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Wyświetlanie 1-40 z 40
Tytuł:
A novel polypeptide from Cervus nippon Temminck proliferation of epidermal cells and NIH3T3 cell line
Autorzy:
Guan, Shu-Wen
Duan, Leng-Xin
Li, Yuan-Yuan
Wang, Ben-Xiang
Zhou, Qiu-Li
Powiązania:
https://bibliotekanauki.pl/articles/1041255.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
polypeptide
velvet antler
promoting cell proliferation
Opis:
A novel polypeptide, velvet antler polypeptide (VAPPs), having a stimulary effect on proliferation of some cell was isolated from the velvet antler of sika deer (Cervus nippon Temminck). This polypeptide consists of a single chain of 32 amino-acid residues VLSAT DKTNV LAAWG KVGGN APAFG AEALE RM. VAPPs showed marked stimulary effect on rat epidermal cells and NIH3T3 cell line (dose range from 10-40 mg·L-1 and 5-80 mg·L-1, respectively).
Źródło:
Acta Biochimica Polonica; 2006, 53, 2; 395-397
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of surface deformation controlled by key strata groups and separation in strip mining
Autorzy:
Luan, Yuan-Zhong
Li, Zeng-Xin
Weng, Li-Yuan
Zhang, Ming-Xin
Powiązania:
https://bibliotekanauki.pl/articles/1402348.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
key strata groups
separation
breaking distance
surface deformation
probability integration
Opis:
In this paper, the key stratum theory is introduced in view of the small surface deformation value of the mining of thick coal mines in Gucheng Coal Mine. The analysis of geological drilling data in Gucheng Goal Mine determines three key strata groups and one main key stratum for controlling the surface deformation of the stratum above the No. 3 coal according to the stiffness and strength condition of the stratum. The breaking distance of the main key stratum in this Mine is determined to be 302–373.7 m in terms of the elastic foundation beam theory and the surface measured basin data. In addition, a large-scale separation model of the main key stratum of the five strip mining face of this Mine is established, and the quantitative calculation formula of the limit spanning of rock beam is proposed and applied to. Finally, the probability integral method is used to predict the surface deformation problem of multiple working faces, and the partition prediction is performed according to the key stratum breaking distance to obtain prediction values of surface deformation consistent with the fracture of key stratum in the study area.
Źródło:
Mining Science; 2020, 27; 303-322
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized limits and a mean ergodic theorem
Autorzy:
Li, Yuan-Chuan
Shaw, Sen-Yen
Powiązania:
https://bibliotekanauki.pl/articles/1220908.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Banach limits
$L$-limits
states
numerical radius
reflexive space
mean ergodic theorem
Opis:
For a given linear operator L on $ℓ^∞$ with ∥L∥ = 1 and L(1) = 1, a notion of limit, called the L-limit, is defined for bounded sequences in a normed linear space X. In the case where L is the left shift operator on $ℓ^∞$ and $X = ℓ^∞$, the definition of L-limit reduces to Lorentz's definition of σ-limit, which is described by means of Banach limits on $ℓ^∞$. We discuss some properties of L-limits, characterize reflexive spaces in terms of existence of L-limits of bounded sequences, and formulate a version of the abstract mean ergodic theorem in terms of L-limits. A theorem of Sinclair on the form of linear functionals on a unital normed algebra in terms of states is also generalized.
Źródło:
Studia Mathematica; 1996, 121, 3; 207-219
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Foreshadow prediction of coal and gas outbursts based on a weighted first-order local-region method
Prognozowanie wyrzutów gazu i węgla na podstawie ważonej metody lokalnej pierwszej potęgi
Autorzy:
Li, Z. Q.
Liu, Z.
Yuan, S.
Powiązania:
https://bibliotekanauki.pl/articles/348565.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ważona metoda lokalna pierwszej potęgi
wyrzuty węgla i gazu
chaotyczny szereg czasowy
prognozowanie wyrzutów
weighted first-order local-region method
coal and gas outbursts
chaotic time series
outburst prediction
Opis:
This paper presents a method for the foreshadow prediction of coal and gas outburst. It was hypothesized that the gas emission prior to coal and gas outburst was nonlinear and the chaotic time series could be used in the short-term prediction. The weighted first-order local-region method was used to analyze the historical monitored gas emission data prior to the coal and gas outburst in a coal mine. The phase space of gas emission time series was reconstructed according to Takens' theory and a dynamic mathematical model of prediction was constructed. Then, the model was applied to predict the gas emission and the results were good. More than 75 percent of the predictive value error constitutes less than 1 percent. The results show that the weighted first-order local-region method is much more precise than some prediction methods and it is also easy to operate. So it is good in application and provides an effective method for coal and gas outburst prediction based on the obviously nonlinear gas emission data.
Niniejsza publikacja przedstawia metodę prognozowania wyrzutów węgla i gazu. Z postawionych hipotez wynika, że emisja gazu, do której dochodzi przed wyrzutem węgla i gazu, ma przebieg nieliniowy, a chaotyczny szereg czasowy może być wykorzystywany w prognozach krótkoterminowych. Do analizy danych historycznych monitorowanej emisji gazu przed wyrzutem węgla i gazu w kopalni zastosowano ważoną metodę lokalną pierwszej potęgi. Przestrzeń fazową szeregu czasowego emisji gazu zrekonstruowano na podstawie twierdzenia Takensa, a następnie sporządzono dynamiczny model matematyczny prognozy. Model ten wykorzystano do prognozy emisji gazu. Wyniki testu były zadowalające. 75 procent błędu wartości prognozowanej stanowi mniej niż 1 procent. Wyniki pokazują, że ważona metoda lokalna pierwszej potęgi jest o wiele bardziej precyzyjna niż wiele innych metod prognostycznych. Ponadto jest ona łatwa do zastosowania. Prostota i skuteczność tej metody czyni ją odpowiednią do prognozowania wyrzutów węgla i gazu na podstawie nieliniowych danych emisji gazu.
Źródło:
AGH Journal of Mining and Geoengineering; 2012, 36, 3; 217-223
1732-6702
Pojawia się w:
AGH Journal of Mining and Geoengineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of digital transformation and MSMEs performance from a spatial perspective: Evidence from China
Autorzy:
Zheng, Bing
Yuan, Yuqing
Li, Huizhuan
Jiang, Yihan
Powiązania:
https://bibliotekanauki.pl/articles/18721474.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
digital transformation
double sampling frame
performance analysis
MSMEs
Opis:
Aim/purpose – Not only have micro, small, and medium enterprises (MSMEs) been regarded as a driving force of the national economy, but they have also become important in promoting innovation and entrepreneurship. In general, today’s MSMEs face problems, such as high business costs, insufficient innovation, and inadequate management capabilities, that have all forced the digital transformation of MSMEs. However, in existing studies, the impact of digital transformation on performance is controversial, and the subjects are generally listed companies. In this paper, we have decided to use micro business survey data and analyze them from a spatial perspective to explore how MSMEs’ digital transformation plays a role in influencing performance and the path of its effect. Design/methodology/approach – We use a sampling method with a dual directory-regional sampling frame to investigate MSMEs in Ningbo City, Zhejiang Province, China and then delve into the impact of digital transformation on enterprise performance from a spatial perspective by the spatial weighted logit model. Findings – Hierarchical analysis shows that there is a large room for improvement in the Digital transformation of enterprises. The digitalization level of an enterprise has a positive impact on performance. While from a spatial perspective, the digitalization level of neighboring enterprises has a negative impact on the performance of the enterprise. Path analysis shows that the digital transformation of enterprises can increase innovation, reduce costs, and improve the performance of enterprises. Originality/value – We provide an empirical basis for vigorously promoting the digital transformation of enterprises, jointly building digital parks, and improving enterprise performance by reducing costs and improving efficiency. At the same time, it provides relevant suggestions for digital transformation for manufacturing MSMEs that are hesitant to see or are at a loss in the digital transformation and helps manufacturing MSMEs to achieve cost reduction and increase efficiency.
Źródło:
Journal of Economics and Management; 2023, 45; 319-343
1732-1948
Pojawia się w:
Journal of Economics and Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Optimization of Underwater Lower-Frequency Sound Insulation for Locally Resonant Sonic Material Using Genetic Algorithm
Autorzy:
Yuan, Bo
Chen, Yong
Tan, Bilian
Li, Bo
Powiązania:
https://bibliotekanauki.pl/articles/177461.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
underwater acoustic
sound insulation
local resonance
statistical optimization
global optimum
Opis:
The locally resonant sonic material (LRSM) is an artificial metamaterial that can block underwater sound. The low-frequency insulation performance of LRSM can be enhanced by coupling local resonance and Bragg scattering effects. However, such method is hard to be experimentally proven as the Best optimizing method. Hence, this paper proposes a statistical optimization method, which first finds a group of optimal solutions of an object function by utilizing genetic algorithm multiple times, and then analyzes the distribution of the fitness and the Euclidean distance of the obtained solutions, in order to verify whether the result is the global optimum. By using this method, we obtain the global optimal solution of the low-frequency insulation of LRSM. By varying parameters of the optimum, it can be found that the optimized insulation performance of the LRSM is contributed by the coupling of local resonance with Bragg scattering effect, as well as a distinct impedance mismatch between the matrix of LRSM and the surrounding water. This indicates coupling different effects with impedance mismatches is the Best method to enhance the low-frequency insulation performance of LRSM.
Źródło:
Archives of Acoustics; 2019, 44, 2; 365-374
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphogenesis and Molecular Characterization of a Little Known Soil Ciliate, Oxytricha nauplia Berger et Foissner, 1987 (Ciliophora, Sporadotrichida)
Autorzy:
Bai, Yang
Li, Song
Li, Yuan
Miao, Miao
Hu, Xiaozhong
Powiązania:
https://bibliotekanauki.pl/articles/52254410.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
ciliature
ontogeny
oxytrichid
phylogeny
SSU rDNA
Opis:
 A Chinese population of Oxytricha nauplia Berger et Foissner, 1987 was recently discovered from the surface soil in the Kuisu Valley, Huhhot, China. Its morphology corresponds well with that of the original population in the body size and shape, the absence of cortical granules, two macronuclear nodules and two micronuclei. Both morphogenesis during binary fission and small subunit of ribosomal gene (SSU rDNA) of the species were first investigated. Though earlier dividers are unavailable for this species, morphogenesis almost proceeds as in congeners by given stages. The SSU rDNA sequence of O. nauplia is 1728 bp long and has a DNA G+C content of 45.72%. Phylogenetic analyses revealed that Oxytricha nauplia grouped with O. paragranulifera first with high support, and then clustered into a subclade including Onychodromopsis flexilis, Paroxytricha ottowi, Paroxytricha longigranulosa and Rigidothrix goiseri, which branched off most congeners, but clustered into the Oxytrichidae clade. 
Źródło:
Acta Protozoologica; 2018, 57, 2; 79-94
0065-1583
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Small mammal fauna from Wulanhuxiu (Nei Mongol, China) implies the Irdinmanhan–Sharamurunian (Eocene) faunal turnover
Autorzy:
LI, QIAN
WANG, YUAN-QING
FOSTOWICZ-FRELIK, ŁUCJA
Powiązania:
https://bibliotekanauki.pl/articles/945478.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
mammalia
rodentia
duplicidentata
anagalidae
eocene
ulan shireh formation
china
erlian basin
Opis:
Wulanhuxiu, a middle Eocene locality in the Erlian Basin, Nei Mongol (China) has been commonly regarded as belonging to the Ulan Shireh Formation, equated with the Irdin Manha Formation. We recognized two separate mammalian faunas of different age from the beds exposed at Wulanhuxiu. The lower fossiliferous horizon contains an anagalid, uncommon duplicidentate representatives (Gomphos progressus sp. nov., Mimolagus, Erenlagus, and Strenulagus), and diverse perissodactyls. This combination of taxa points to an Irdinmanhan age, but one element of the fauna (Schlosseria) may represent an Arshantan relic. Overall, the assemblage comprises “paleoplacental” mammals mixed with “neoplacentals”. The upper horizon is less species-rich and the only paleoplacentals present are scarce creodonts. However, this horizon is marked by abundant remains (including postcranial material) of the lagomorph Gobiolagus and by the presence of an advanced form of Gobiomys (Rodentia), and is most probably Sharamurunian in age. Thus, Wulanhuxiu documents replacement, albeit incomplete, of paleoplacentals by neoplacentals in the Chinese Eocene record.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 4; 759-776
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Cotton Matured Fibre Quality and the Super-Molecular Structure in Upland Cotton RILs
Analiza jakości dojrzałych włókien bawełny Upland i jej struktury nadcząsteczkowej
Autorzy:
Wang, Y.
Li, C
Shang, H
Li, B
Liu, A
Yuan, Y
Powiązania:
https://bibliotekanauki.pl/articles/231848.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
upland cotton
recombinant inbred lines
fibre super-molecular structure
fibre quality
dojrzałe włókna bawełny
bawełna Upland
zmodyfikowana genetycznie bawełna
cechy włókniste bawełny
super-molekularna struktura włókien
jakość włókna
Opis:
A RIL(recombinant inbred lines) population with 196 F6:9 lines was developed from an F2 population of upland cotton (Gossypium hirsutum L.) cross of sGK9708×0-153. sGK9708 is a commercial transgenic variety with Bt+CpTI genes resistant to budworm and 0-153 with high fibre quality. Five materials with high fibre strength and five materials with low fibre strength from the recombinant inbred lines were researched [1]. Ten materials of super-molecular structure and fibre quality were studied by X-ray diffraction and the HVI900 technique. The results indicated that cotton matured fibre quality should mainly depend on the decrease in the orientational parameter in the crystalline section, especially the orientational separate and orientational distribution angles. The correlation of fibre maturity, linear density and the fibre super-molecular structure is an innovation in the study. Studies on the correlation of cotton fibre quality and the fibre super-molecular structure provide a scientific basis for the improvement cotton fibre quality.
Artykuł dotyczy badań jakości dojrzałych włókien bawełny amerykańskiej Upland i jej struktury nadcząsteczkowej. Uzyskano zmodyfikowany genetycznie gatunek bawełny amerykańskiej Upland za pośrednictwem sztucznego samozapylenia bawełny wykazującej cechy włókniste (linii wsobnej). Dla uzyskanych w opisany sposób włókien bawełny przeprowadzono wszechstronne badania właściwości fizycznych, a także struktury nadcząsteczkowej. Uzyskane wyniki badań skonfrontowano z właściwościami fizycznymi i strukturą nadczasteczkową tradycyjnej bawełny amerykańskiej Upland posiłkując się w tym celu analizą korelacyjną.
Źródło:
Fibres & Textiles in Eastern Europe; 2014, 5 (107); 28-33
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative methodology for recycling iron from magnetic preconcentrate of an iron ore tailing
Autorzy:
Yu, J.
Han, Y.
Gao, P.
Li, Y.
Yuan, S.
Li, W.
Powiązania:
https://bibliotekanauki.pl/articles/110888.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetic preconcentrate
iron ore tailing
iron recycling
fluidized magnetization roasting
magnetic separation
Opis:
Iron ore tailing is a kind of hazardous solid waste produced by iron and steel industry. In order to separate and recycle iron from the magnetic preconcentrate of an iron ore tailing, an innovative technological route of fluidized magnetization roasting followed by low-intensity magnetic separation was proposed in this paper. The effects of roasting temperature, dosages of reducing gas CO and fluidizing gas N2 on recovery rate of iron were carried out and optimized. The results showed that the hematite was almost reduced to magnetite by a gas mixture of 4 m3/h CO and 1 m3/h N2 at roasting temperature of 540 °C. Under the optimized conditions, a magnetic concentrate assaying 61.4 wt% Fe with a recovery rate of 81.8% was obtained from the magnetic preconcentrate of an iron ore tailing. The iron chemical phase, X-ray diffraction (XRD), and optical metallographic microscope analyses revealed that siderite was converted to magnetite successfully after roasting, and some coarse magnetite-hematite interlocking particles were formed due to insufficient reaction time, which could also be recovered by magnetic separation after liberating from gangue minerals.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 668-676
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of calcination temperature on activation behaviors of coal-series kaolin by fluidized bed calcination
Autorzy:
Yuan, S.
Han, Y.
Li, Y.
Gao, P.
Yu, J.
Powiązania:
https://bibliotekanauki.pl/articles/109800.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal-series kaolin
fluidized bed calcination
calcination temperature
activation behaviors
Opis:
This paper is aimed at investigating activation behaviors for coal-series kaolin using fluidized bed calcination as a novel method. The properties of calcined products at different temperature by fluidized bed calcination were evaluated by determination of weight loss rate, whiteness, chemical oxygen demand (COD), aluminum dissolution degree. The thermal behaviors and reaction mechanism were characterized by thermo gravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), particle size distribution (PSD) and scanning electron microscopy (SEM). The results showed that calcination temperature was essential factor determining the properties and crystallinity of calcined products using fluidized bed calcination. Coal-series kaolin transformed into irregular and amorphous metakaolin with excellent properties as calcined at 600-900 °C, which attributed to the dehydroxylation of kaolinite and combustion of carbon/organic matter. Calcined kaolin eliminated activity ascribed to the recrystallization into mullite when calcination temperature was over 1000 °C. It was believed that fluidized bed calcination was an efficient thermal activation technology for coal-series kaolin and the calcination temperature should be controlled accurately.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 590-600
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of air inlet layout on the inner flow field for a vertical turbo air classifier
Autorzy:
Yu, Yuan
Li, Xingshuai
Zhang, Yu
Jiao, Zhiwei
Liu, Jiaxiang
Powiązania:
https://bibliotekanauki.pl/articles/27323654.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
turbo air classifier
powder technology
air inlet layout
numerical simulation
classification performance
Opis:
In this study, the influence of air inlet layout on the flow field distribution and particle movement trajectory for the vertical turbo air classifier are analyzed comparatively using the numerical simulation method. The air inlet layout adjustment can increase the axial velocity and turbulent dissipation rate at the feeding inlet and do not generate the axial negative velocity, which improves powder material pneumatic transportation and dispersion capacity; the air inlet layout adjustment can match the airflow rotation direction with the rotation direction of the rotor cage, which can eliminate the vortices in the rotor cage channel effectively. Moreover, the particle movement time is shortened and fast classification is completed, which can decrease the particle agglomeration probability and weaken the ‘fish-hook’ effect. The optimization scheme of the air inlet layout is Type-BC. In accordance with the numerical simulation results, the calcium carbonate classification experimental results indicate that the classification performance of the classifier is improved using Type-BC.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 175859
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Helicobacter pylori cytotoxin-associated gene A impairs the filtration barrier function of podocytes via p38 MAPK signaling pathway
Autorzy:
Yang, Man
Wang, Ling
Gu, Li-jie
Yuan, Wei-jie
Powiązania:
https://bibliotekanauki.pl/articles/1038590.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
CagA
ZO-1
p38 MAPK
podocyte
proteinuria
Opis:
Helicobacter pylori (Hp) specific antigens were found deposited in the glomeruli in some kidney diseases. However, the underlying molecular mechanisms remain to be elucidated. The aim of this study was to investigate the effect of cytotoxin associated gene A protein (CagA), a key virulence factor of Hp, on mouse podocytes. Cells were cultured and treated with recombinant CagA protein. The expression of the tight junction protein ZO-1 and p38 MAPK signaling pathway activation were measured with real-time RT-PCR and western blotting. The filtration barrier function of podocytes was evaluated with albumin influx assay. CagA decreased the expression and membrane distribution of ZO-1, impaired the filtration barrier function of podocytes, while activating p38 MAPK signaling pathway in these cells. Selective p38 MAPK inhibition partly prevented CagA-induced filtration barrier dysfunction of podocytes through ameliorating ZO-1 downregulation. Taken together, the results suggested that CagA, at least via p38 MAPK signaling pathway, may induce podocyte injury. Anti-Hp therapy may be beneficial for the treatment of kidney diseases related to Hp antigen deposition.
Źródło:
Acta Biochimica Polonica; 2017, 64, 3; 471-475
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Job category differences in the prevalence and associated factors of insomnia in steel workers in China
Autorzy:
Li, Xiaoming
Cui, Shiyue
Wu, Jianhui
Wang, Lihua
Yuan, Juxiang
Powiązania:
https://bibliotekanauki.pl/articles/2116661.pdf
Data publikacji:
2020-03-13
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
insomnia
shift work
job stress
life events
steel workers
job category
Opis:
ObjectivesThis study aimed to investigate the prevalence of insomnia and risk factors among different job categories of steel workers in China, in order to improve their quality of occupational life.Material and MethodsA cross-sectional face-to-face survey was conducted which involved 5834 steel workers from a large enterprise located in northern China, including front-line, maintenance and inspection, and other auxiliary workers. The Athens Insomnia Scale and the Job Content Questionnaire were used to assess the status of insomnia and job stress/social support, respectively. Multivariable logistic regression was used to identify factors influencing insomnia.ResultsThe overall prevalence of insomnia was determined at 42.0% (95% confidence interval: 40.7%–43.2%). For front-line, maintenance and inspection, and other auxiliary workers, the prevalence was 42.3%, 39.8%, and 47.9% (p = 0.001), respectively. The participants with high stress and low support, and those who had experienced ≥2 major life events in the past 12 months, compared to those with low stress and high support, and those without major events, displayed an increased risk of insomnia among all 3 job categories (the adjusted odds ratio ranged 1.56–2.38 and 1.30–1.75, respectively). The educational level, shift work, alcohol consumption, and present illness were identified as influencing factors of insomnia for 1 or 2 job categories.ConclusionsThe prevalence of insomnia was the highest in the group of other auxiliary steel workers among the 3 job categories of steel workers under consideration. While the influencing factors of insomnia differed among the groups, job stress and major life events were common risk factors of insomnia among the 3 categories of steel workers.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2020, 33, 2; 215-233
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter identification approach using improved teaching and learning based optimization for hub motor considering temperature rise
Autorzy:
Li, Yong
Wang, Yuan
Zhang, Taohua
Hu, Han
Wu, Hao
Powiązania:
https://bibliotekanauki.pl/articles/2203368.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
parameters identification
teaching–learning-based optimization
hub motor
temperature rise
Opis:
Temperature rise of the hub motor in distributed drive electric vehicles (DDEVs) under long-time and overload operating conditions brings parameter drift and degrades the performance of the motor. A novel online parameter identification method based on improved teaching-learning-based optimization (ITLBO) is proposed to estimate the stator resistance, -axis inductance, -axis inductance, and flux linkage of the hub motor with respect to temperature rise. The effect of temperature rise on the stator resistance, -axis inductance, -axis inductance, and magnetic flux linkage is analysed. The hub motor parameters are identified offline. The proposed ITLBO algorithm is introduced to estimate the parameters online. The Gaussian perturbation function is employed to optimize the TLBO algorithm and improve the identification speed and accuracy. The mechanisms of group learning and low-ranking elimination are established. After that, the proposed ITLBO algorithm for parameter identification is employed to identify the hub motor parameters online on the test bench. Compared with other parameter identification algorithms, both simulation and experimental results show the proposed ITLBO algorithm has rapid convergence and a higher convergence precision, by which the robustness of the algorithm is effectively verified.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 99--115
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of YSZ coatings on nickel-based alloys by anodic electrophoretic deposition
Autorzy:
Binxia, Yuan
Tianzhong, Chen
Yongzhi, Shang
Haibo, Xue
Min, Li
Powiązania:
https://bibliotekanauki.pl/articles/2204142.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
YSZ coating
anodic electrophoretic deposition
suspension solution
nickel-based alloys
Opis:
In the paper, YSZ coatings were prepared on nickel-based alloy substrates by anodic electrophoretic deposition. The YSZ suspension solution was obtained under stirring and ultrasonic treatment, in which the anhydrous ethanol and acetylacetone were used as the dispersion medium and ammonium polyacrylate was used as the dispersant of the suspension. The effects of different deposition voltage and deposition time on YSZ coating were investigated. Meantime, the microstructure of the coating surface was observed by metallographic microscope. It was found that the high-quality YSZ coating could be obtained by deposition at 60 V for 2–3 min. Finally, the effect of sintering temperature on coating quality was investigated by X-ray diffractometer and scanning electron microscopy. The results showed that the YSZ coating bonded closely with the substrate after sintering at 1200 °C, and the porosity of the YSZ coating increased after sintering.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 1; 8--11
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The depression mechanism on pyrite in a low-alkaline system with combined depressants : Experiment, HSC, DFT and ToF–SIMS studies
Autorzy:
Li, Suqi
Yuan, Jiaqiao
Ding, Zhan
Li, Jie
Yu, Anmei
Wen, Shuming
Bai, Shaojun
Powiązania:
https://bibliotekanauki.pl/articles/24085821.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pyrite
calcium hypochlorite
lime
depression
low alkaline system
Opis:
Depression of pyrite in a low-alkaline system has sparked soaring interests for the multi-metal sulfide minerals flotation recently. This study investigates effects of combined depressants (Ca(ClO)2 and CaO) on pyrite flotation with butyl xanthate (KBX). Micro-flotation experiments indicate that the addition of 200 mg/L combined depressants (a mass ratios of CaO to Ca(ClO) 2 of 2:3) and 1.0×10−3 mol/L KBX at pH 9.5 can effectively depresses the flotation of pyrite, and a minimum pyrite recovery rate of 12.5% is obtained. Basic thermodynamic evaluation results confirm the participation of Ca(ClO) 2 significantly decrease the negative Gibbs free energies of pyrite oxidation reaction. Besides, the calcium species (Ca(OH) 2, Ca2+ and Ca(Cl) 2) will spontaneously transform into CaCO3,and it is the ultimate dominant calcium species in the CO32- system. Density functional theory (DFT) results indicate that CaCO3 can chemically adsorb onto the pyrite surface with an adsorption energy of –671.13 kJ/mol. The O1 and Ca atoms mainly contribute to the bonding process and are responsible for the stable adsorption of CaCO3. ToF-SIMS results provide strong evidence that the combined depressants increase the amount of hydrophilic species and decrease dixanthogen adsorption onto the pyrite surface. The thickness of the whole formed hydrophilic species is approximately 50 nm. Semiquantitative amounts of hydrophilic species follow the order of hydroxy calcium>iron carbonyl>calcium carbonate. Overall, hydrophilic species repulse adsorption of dixanthogen and significantly reduce the flotation performance of pyrite.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 168454
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First-principles calculations on phase transition and elastic properties of CoN
Autorzy:
De-Chun, He
Yong, Peng
Su-Yuan, Li
Yong-Lin, He
Powiązania:
https://bibliotekanauki.pl/articles/1075580.pdf
Data publikacji:
2016-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
62.20.-x
62.20.de
62.50.-p
62.20.dq
Opis:
The structural phase transition and elastic properties of CoN are investigated by ab initio plane-wave pseudopotential density function theory method. The equilibrium lattice parameters a₀, elastic constants C_{ij}, bulk modulus B₀ and its derivative B'₀ are calculated. From the usual condition of equal enthalpy, the phase transition of CoN from zinc-blende to rocksalt structure occurs at 35.4 GPa with a volume collapse of about 15.6%, consistent with the calculated result 36 GPa (FP-LDA), but an uncertainty is about 4.4 GPa compared with the 31 GPa (ASA-GGA). All three independent elastic constants, C₁₁, C₁₂, and C₄₄ for CoN are calculated from direct computation of stresses generated by small strains. Both C₁₂ and C₄₄ are less sensitive to pressure as compared with C₁₁. The calculated conclusions offer theoretical data for the further research of the mechanical properties for CoN.
Źródło:
Acta Physica Polonica A; 2016, 130, 3; 743-747
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of overlying water pH, dissolved oxygen and temperature on heavy metal release from river sediments under laboratory conditions
Autorzy:
Huang, Y.
Zhang, D.
Xu, Z.
Yuan, S.
Li, Y.
Wang, L.
Powiązania:
https://bibliotekanauki.pl/articles/204852.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heavy metal
release
river sediment
Opis:
The heavy metal release experiments were conducted in the laboratory to examine the effects of 3 factors - pH, dissolved oxygen (DO), and temperature on the metal release from sediments taken from the Huangpu River. The metal concentrations in the dry sediments ranged from 0.030 to 0.296 mg g-1 for Cr, 0.021 to 0.097 mg g-1 for Ni, 0.014 to 0.219 mg g-1 for Cu, 0.035 mg to 0.521 mg g-1 for Zn, 0.0002 to 0.001 mg g-1 for Cd and 0.023 to 0.089 mg g-1 for Pb. Most of the metals found in the sediments were in the form of residual fraction, the exchangeable fraction consisted of only a small portion of total metals. The average dissolved metal concentrations in the overlying water during the 13-day period under different conditions were ranging from 0.82 to 1.93 μg L-1 for Cr, 1.08 to 4.19 μg L-1 for Ni, 40.79 to 82.28 μg L-1 for Cu, 20.30 to 29.96 μg L-1 for Zn, 1.57 to 4.07 μg L-1 for Cd, and 22.26 to 75.50 μg L-1 for Pb, respectively. Statistical interpretation of the data indicated that pH (7, 8, 9), dissolved oxygen DO (1.0 and 5.0 mg L-1) and temperature (4, 16, 25°C) had no significant effects on the heavy metal release under the studied conditions. Cu and Pb had the highest release flux, while Cd, Pb and Cu had higher mobility. The main factors controlling the metals release might be the inherent characters of metals and sediments.
Źródło:
Archives of Environmental Protection; 2017, 43, 2; 28-36
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative flotation technology for the lime-depressed pyrite recovery from copper sulphide ore via acid mine drainage (AMD) activation
Autorzy:
Yuan, Jiaqiao
Ding, Zhan
Bi, Yunxiao
Li, Jie
Wen, Shuming
Bai, Shaojun
Powiązania:
https://bibliotekanauki.pl/articles/2175438.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
copper sulfide ore
acid mine drainage (AMD)
lime-depressed-pyrite
activator
hydrophilic species
Opis:
In this study, an innovative flotation technology consisted of Cu differential flotation with high alkali lime and pyrite recovery with acid mine drainage (AMD) activation was investigated for the cleaner beneficiation of the copper sulfide ore. Flotation test results showed that H2SO4 -CuSO4 and AMD could effectively activate the pyrite flotation with SBX collector. Moreover, the recovery of S concentrate is increased by 5.33% in the AMD system. Adsorption amount results of SBX collector indicated that the hydrophilic species (Ca2+, CaOH+ and FeOOH) were formed on the pyrite surfaces in the high alkali lime craft (pH=11.3) and degraded the interaction between SBX and pyrite surfaces. AMD can effectively clear off the hydrophilic calcium species and the copper ions originated from the AMD absorb onto the pyrite surfaces, facilitating the SBX collector adsorption. Composition analysis results of tailings water confirmed that the tailing water obtained by the AMD flotation system was more desirable to be recycled in the Cu differential flotation due to its higher pH value (8.7). The present study provides a novel approach for the treatment of AMD, and has the vital practical significance for the emission reduction of AMD and the increase of beneficiation profits.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 152609
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of pollution accumulation on coating aging of UHV line insulators with different suspension height in coal-ash polluted area
Autorzy:
Lan, Lei
Mu, Lin
Wang, Yu
Yuan, Xiaoqing
Wang, Wei
Li, Zhenghui
Powiązania:
https://bibliotekanauki.pl/articles/140717.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aging
pollution component
pollution degree
RTV coating
Opis:
Room temperature vulcanized (RTV) silicone rubber is widely used to prevent pollution flashover with its excellent hydrophobicity and hydrophobicity transfer. However, RTV coatings are at the risk of deterioration and failure in heavily polluted operating environment. In this paper, RTV coated insulators with different suspension heights operating in coal ash polluted areas were sampled. Pollution degree, pollution composition and aging degree of coatings were tested. The result shows that the insoluble pollution contains Al(OH)3 filler precipitated from RTV coating, which indicates the aging of the RTV coating. The top surface coating is more affected by ultraviolet and rainwater than the bottom surface resulting in more serious degradation. As the pollution degree of the lower phase insulator is heavier than that of the upper phase insulator, the erosion effect of pollution on the RTV coating is more intense. The fillers and rubber molecules of RTV continuously precipitate into the pollution layer, leading to further aging. Therefore, the overall aging degree of the lower insulator coating is more serious than that of the upper insulator coating.
Źródło:
Archives of Electrical Engineering; 2020, 69, 1; 39-56
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on dose correction method of vehicle-borne environmental radiation measurement equipment
Autorzy:
Xu, Jie
Ren, Jizhou
Yang, Jianbo
Fan, Jiawen
Li, Rui
Li, Hui
Huang, Weiqi
Yuan, Biao
Powiązania:
https://bibliotekanauki.pl/articles/2055679.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dose correction factor
reference radiation field
vehicle-borne environmental radiation measurement equipment
Opis:
This study establishes a near-ground reference radiation field based on typical radionuclides of the Fukushima accident in response to the need for vehicle-borne environmental radiation measurement equipment that can accurately evaluate the environmental dose of nuclear accidents. The Monte Carlo code FLUKA is used to study the environmental dose of such equipment in the early and mid-late reference radiation fields of nuclear accidents. Results of the air dose rate at 1 m above the ground were corrected to eliminate data difference between diverse measurement platforms. Simulation results show that t he dose correction factor (CF) fluctuates at approximately 0.8813 in the early reference radiation field and at approximately 0.6711 in the mid-late reference radiation field . This deviation of the dose CF in the early and mid-late reference radiation field s is within 2% and is not affected by the change in detector position. This research can be applied to obtain more accurate measurement of an ambient dose in the near-ground radiation field and support the vehicle-borne environmental radiation measurement technology.
Źródło:
Nukleonika; 2021, 66, 3; 103--110
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on synthesis and photoelectric properties of AgInS2 quantum dots
Autorzy:
Yuan, Binxia
Luo, Zige
Sun, Yongjun
Cao, Sheng
Cao, Lan
Li, Min
Powiązania:
https://bibliotekanauki.pl/articles/2106479.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
AgInS
Quantum dots
Optical properties
Photocatalytic hydrogen production
Opis:
AgInS2 Quantum dots (AIS QDs) have high quantum yield and catalytic performance, which is promising materials in photo-catalytic and optoelectronic fields. In the paper, it adopted a simple and non-toxic method to synthesize AIS QDs. The effect of reaction temperature on the growth mechanism, optical and physical properties of AIS had been extensively investigated by using L-cysteine as the sulfur source, and their application in catalytic hydrogen production was also studied. The results demonstrated that the fluorescence properties will be quenched with the increase of temperature, indicating that the separation speed of electron hole pairs of samples obtained at higher temperature was faster. Meantime, the electron transport capacity and the photocurrent had also improved with the increase of reaction temperature. Finally, the sample obtained at 100 oC had higher hydrogen production rate.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 2; 21--26
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective agglomeration of magnetite in entlandite-serpentine system and implication for their separation
Autorzy:
Lu, J.
Yuan, Z.
Liu, J.
Li, L.
Wang, N.
Meng, Q.
Powiązania:
https://bibliotekanauki.pl/articles/110411.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
serpentine
pentlandite
magnetite
selective magnetic agglomeration
magnetic separation
Opis:
In nickel sulfide processing, magnesium silicates (serpentines) can easily form slime coatings or hetero-aggregation on pentlandite surfaces, and hence decrease the pentlandite flotation rate and recovery. In this work, magnetic separation of pentlandite from serpentine using selective magnetic coating through adding magnetite fines as magnetic seeds was investigated. Interactions of magnetite-pentlandite and magnetite-serpentine were calculated by the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory. The results show that the interaction of magnetite-pentlandite was obviously stronger than that of magnetite-serpentine with an external weak magnetic field (4776 A/m-1). Therefore, fine magnetite fractions selectively adhered to the pentlandite surfaces and enhanced its magnetism, resulting in being separated from serpentine by magnetic separation, which was further verified by magnetic coating-magnetic separation and SEM observations.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 943-955
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics and metal leachability of natural contaminated soil under acid rain scenarios
Autorzy:
Tan, Wenfa
Li, Yuan
Ding, Lei
Wang, Yachao
Li, Jiangxiang
Deng, Qinwen
Guo, Feng
Xiao, Xue
Powiązania:
https://bibliotekanauki.pl/articles/205435.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heavy metal
soil pollution
fraction analysis
soil leaching
Opis:
Contamination of soil with heavy metals has become a worldwide environmental problem, and receives great attention. In this study, we aim to investigate soil pollution level affected by an industrial district nearby. The total amount of typical heavy metals in the soils (Hengyang Songmu Industrial Park, Hunan Province, China) was analyzed. In addition, the fraction analysis and laboratory simulation leaching via different pH rainwater was carried out to study the migration and transformation of heavy metals. The main results show that the contents of Cu, Zn, Pb, Cr and Cd in the samples were higher than the soil background values in Hunan Province. The heavy metals forms, analyzed by sequential extraction method, show that the proportion of the unstable form of Cd, Zn and Pb was more than 50%. Igeo values indicate that the heavy metal pollution degree of soil sample #5 at the investigated area is recorded in the order of Cd(6.42), Zn(2.28), Cu(1.82), Pb(1.63), and Cr(0.37). Cu, Zn, Pb, Cr and Cd in this area could pose a potential leaching risk to the environment which may affect the food chain and constitute a threat to human health. It would be necessary to take steps to stabilize and monitor the heavy metals in soil.
Źródło:
Archives of Environmental Protection; 2019, 45, 2; 91-98
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic Analyses of the Genus Architricha and Pleurotricha curdsi (Ciliophora, Oxytrichidae), with Redescriptions of Their Morphology
Autorzy:
Xu, Yuan
LI, Lifang
Fan, Xinpeng
Pan, Hongbo
GU, Fukang
Al-Farraj, Saleh A.
Powiązania:
https://bibliotekanauki.pl/articles/763754.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Opis:
Two oxytrichids Architricha indica Gupta et al., 2006 and Pleurotricha curdsi (Shi et al. 2002) Gupta et al., 2003 collected in East China, were studied using live observation and the silver staining method. The description and morphometric characterization of the new populations were supplied. The Shanghai population of A. indica differs from the Indian population in the number of cirri in the third right marginal row (average of 16.8 vs. 21.1). The Shanghai population of P. curdsicorresponds well with the Indian population, but it differs from the other Chinese population in the number of right marginal rows (two vs. three). The early process of reorganization of A. indica was studied, and a difference on the formation of anlage V was found compared to the original report. The small subunit rRNA genes of both species were sequenced for the first time. The phylogenetic analyses based on SSU rRNA gene sequence data revealed that Architricha is sister to the assemblage of Pseudouroleptus caudatus and two Strongylidium, while P. curdsi clusters with its congener P. lanceolata and is located in Stylonychinae.
Źródło:
Acta Protozoologica; 2015, 54, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of MoS2 Nanosheet Fillers on Poly(vinyl alcohol) Nanofibre Composites Obtained by the Electrospinning Method
Wpływ zastosowania wypełniaczy MoS2 na kompozyty z nanowłókien poli(alkoholu winylowego) otrzymane metodą elektroprzędzenia
Autorzy:
Yuan, Bin
Liu, Jun
Qiu, Lei
Hui, Qian
Chang, Meng-Jie
Li, Ya-Qing
Powiązania:
https://bibliotekanauki.pl/articles/233334.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electrospinning
MoS2 nanosheet
poly(vinyl alcohol)
composite
nanofibre
elektroprzędzenie
nanoskładnik MoS2
poli(alkohol winylowy)
kompozyt
nanowłókno
Opis:
The graphene-like two dimensional (2D) inorganic materials have been been shown great interest for a variety of applications. In this work, polymer composite nanofibres containing molybdenum disulfide (MoS2) nanosheets were obtained by electrospinning. The MoS2 nanosheets were well dispersed inside the fibres, and the nanofibres maintained the fibre morphology well with the MoS2 nanosheets embedded. The incorporation of MoS2 nanosheets changes polymer nanofibre morphology from round to ribbon-like. Moreover, through thermogravimetric (TG) analysis and dynamic mechanical thermal analysis (DMTA) measurements, it was found that the MoS2 nanosheets as an additive material led to an increase in thermal stability and in the storage modulus. This work comprises an extensive approach to producing a novel 2D inorganic-organic composite structure, which should be applicable for membrane engineering with enhanced thermal and mechanical stability.
Dwuwymiarowe nieorganiczne materiały podobne do grafenu wywołały liczne zainteresowanie w różnych zastosowaniach. W pracy otrzymano metodą elektroprzędzenia kompozytowe nanowłókna polimerowe zawierające disiarczek molibdenu (MoS2). Nanoskładniki MoS2 były dobrze rozproszone we włóknach, a ich morfologia była na zadowalającym poziomie. Włączenie nanoskładników MoS2 zmienia nanowłókna polimerowe z morfologii okrągłej na wstążkową. Co więcej, dzięki analizie termograwimetrycznej (TG) i pomiarom dynamicznej mechanicznej analizy termicznej (DMTA) stwierdzono, że dodatek MoS2 może zapewnić wzrost stabilności termicznej i zwiększyć moduł przechowywania. Praca prezentuje rozszerzone podejście do produkcji nowej dwuwymiarowo nieorganiczno-organicznej struktury kompozytowej, która może mieć zastosowanie w wytwarzaniu membran o podwyższonej stabilności termicznej i mechanicznej.
Źródło:
Fibres & Textiles in Eastern Europe; 2020, 3 (141); 62-67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of the Penetration Characteristics of Ni-Al and Pure Cu Shaped Charge Liners
Autorzy:
Liu, Yingbin
Zhang, Chaoxia
Hu, Xiaoyan
Yang, Li
Sun, Miao
Zhang, Zeng
Yuan, Lei
Powiązania:
https://bibliotekanauki.pl/articles/27788048.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
shaped charge liners
Ni-Al
penetration experiments
white band
microstructure analysis
Opis:
In order to investigate the correlation between the reactivity of Ni-Al and micro-structural differences in the crater walls, penetration experiments were performed with Ni-Al and pure Cu shaped charge liners (SCLs). The experimental results showed that the average penetration depth of Cu jets is 2.3 times that of Ni-Al jets, but the crater entrance diameter of Ni-Al jets is larger by 26.6%. The microstructure of the recovered targets was characterized using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and a Vickers micro-hardness system. The Ni-Al “white” band was thicker than that of Cu because it releases a lot of heat. The micro-hardness test showed that the “white” band had a relatively high hardness, and the “white” band hardness in the tail was more significant than that in the head. However, the micro-structural evolution of the crater walls is related to the reactivity of Ni-Al, but is also related to other factors. Combined with the macro penetration results and the evolution of the micro-structure of the crater walls, the “white” band can absorb impact energy more strongly and weaken the jet breaking ability or armour protection ability.These results can provide more valuable reference for designing shaped charge warheads and protection structures.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 2; 199--222
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical study of the uniaxial compressive stress-strain relationship of a rock mass with two parallel joints
Autorzy:
Xiong, L. X.
Yuan, H. Y.
Zhang, Y.
Zhang, K. F.
Li, J. B.
Powiązania:
https://bibliotekanauki.pl/articles/231076.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
masa skalna łączona
złącze równoległe
siła szczytowa
jointed rock mass
parallel joint
peak strength
Opis:
A “rock bridge”, defined as the closest distance between two joints in a rock mass, is an important feature affecting the jointed rock mass strength. Artificial jointed rock specimens with two parallel joint fractures were tested under uniaxial compression and numerical simulations were carried out to study the effects of the inclination of the rock bridge, the dip angle of the joint, rock bridge length, and the length of joints on the strength of the jointed rock mass. Research results show: (1) When the length of the joint fracture, the length of the rock bridge, and the inclination of the rock bridge stay unchanged, the uniaxial compressive strength of the specimen gradually increases as the inclination of the joint fracture increases from 0° to 90°. (2) When the length of the joint fracture, the length of the rock bridge, and the inclination of the joint fracture stay unchanged, the uniaxial compressive strength of the specimen shows variations in trends with the inclination of the rock bridge increasing from 30° to 150° (3). In the case when the joint is angled from the vertical loading direction, when the dip angle of the joint fracture, the inclination of the rock bridge, and the length of the rock bridge stay unchanged, the uniaxial compressive strength of the specimen gradually decreases with an increasing length of joint fracture. When the dip angle of the joint fracture, the inclination of the rock bridge, and the length of the joint fracture stay unchanged, the uniaxial compressive strength of the specimen does not show a clear trend with an increase of the length of the rock bridge.
Źródło:
Archives of Civil Engineering; 2019, 65, 2; 67-80
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Cryogenic Treatment on Wear Resistance and Microstructure of 42CrMo Steel
Autorzy:
Zhang, Haidong
Yan, Xianguo
Chen, Zhi
Zhao, Minna
Tang, Liang
Gao, Yuan
Li, Fan
Huang, Yao
Li, Junji
Powiązania:
https://bibliotekanauki.pl/articles/2048794.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cryogenic treatment
orthogonal design method
hardness
coefficient of friction
wear resistance
microstructure
Opis:
In this work, thermo-mechanically treated 42CrMo steel was subjected to cryogenic treatment conducted by means of orthogonal design method, followed by low-temperature tempering to investigate the effect of different parameters of cryogenic treatment on wear resistance of 42CrMo steel and to optimize parameters of cryogenic treatment for improving wear resistance. The results of hardness test and wear test show that cryogenic treatment significantly improves wear resistance with marginal changes in coefficient of friction and hardness. Specifically, cryogenic temperature has the largest impact on wear resistance of 42CrMo steel, holding time has medium impact, and the parameter of treatment cycles has the least impact. The optimum parameters of cryogenic treatment are -196°C for 12 hours with one cycle for improving wear resistance. The results of scanning electron microscopy (SEM) and X-ray diffractometry (XRD) analysis indicate that marginal changes in hardness and coefficient of friction may be owing to little amount of transformation of retained austenite, and the significant influence of cryogenic treatment on improving wear resistance of 42CrMo steel can be mainly attributed to segregation of carbon atoms promoted by cryogenic treatment resulting in more precipitation of carbides in subsequent tempering.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 1; 127-135
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An association between cumulative exposure to light at night and the prevalence of hyperuricemia in steel workers
Autorzy:
Li, Xiaoming
Xu, Xianghui
Song, Yang
Cui, Shiyue
Xue, Chao
Wang, Lihua
Wu, Jianhui
Yuan, Juxiang
Powiązania:
https://bibliotekanauki.pl/articles/2085783.pdf
Data publikacji:
2021-06-28
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
uric acid
circadian rhythms
hyperuricemia
steel workers
light at night
restricted cubic spline
Opis:
ObjectivesExposure to light at night (LAN) can disturb circadian endocrine and metabolic rhythms. Hyperuricemia (HUA) is an early-onset metabolic disorder. However, it is still not clear whether LAN exposure increases the prevalence of HUA.Material and MethodsThe authors used crosssectional data on the Beijing-Tianjin-Hebei occupational populations cohort from March–July 2017. A total of 7664 steel workers were finally selected to investigate the relationship between LAN exposure and the prevalence of HUA among steel workers. The authors collected demographic and socio-economic data, as well as information on lifestyle factors, anthropometric measures, and laboratory tests. The restricted cubic spline method was used to analyze the dose-response relationship between cumulative LAN exposure and the prevalence of HUA. Logistic regression analyses were used to fit the relationship between them.ResultsThe average age of the participants was 43.5±8.6 years; 7051 (91.7%) of them were males, 2749 (35.9%) reported to suffer from HUA, and 1241 (16.2%) were not exposed to LAN. There was a significant non-linear dose-response relationship between them. After adjustment for the confounding factors, including demographic data, lifestyle factors, etc., the lower LAN exposure was significantly associated with HUA (0–1931.7 days, OR = 1.180, and the 95% CI: 1.000–1.394; 1931.7–4343 days, OR = 1.215, 95% CI: 1.035–1.426).ConclusionsThis study revealed that a certain amount of exposure to LAN is independently related to the prevalence of HUA in steel workers in China.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 3; 385-401
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The presence of Chlamydia phage PhiCPG1 capsid protein VP1 genes and antibodies in patients infected with Chlamydia trachomatis
Autorzy:
Ma, Jingyue
Liu, Yuan
Liu, Yuanjun
Li, Lingjie
Hou, Shuping
Gao, Xibo
Qi, Manli
Liu, Quanzhong
Powiązania:
https://bibliotekanauki.pl/articles/1038770.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Chlamydia trachomatis
Chlamydia bacteriophage
capsid protein
VP1
Opis:
Chlamydia phage PhiCPG1 has been found in Chlamydia caviae in a guinea pig model for inclusion conjunctivitis, raising the possibility that Chlamydia phage is also present in patients infected with C. trachomatis (Ct). In the present study, we assayed for presence of Chlamydia phage capsid protein VP1 genes and antibodies in 84 non-Ct controls and 206 Ct patients using an enzyme-linked immunoassay (ELISA), followed by verification with Western blot. None of the subjects were exposed to an antibiotic treatment or had a C. pneumoniae infection. The VP1 antibody test was positive in both, the ELISA and Western blot assay, in 4 Ct patients. PCR amplification experiments revealed presence of the VP1 gene in 5 Ct patients. The results suggest that Chlamydia phage capsid protein VP1 may exist in some Ct patients.
Źródło:
Acta Biochimica Polonica; 2016, 63, 3; 501-504
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and Properties of Chain Branched Nitrocellulose
Autorzy:
Liu, Yanhua
Shao, Ziqiang
Yuan, Jingjing
Jia, Shuai
Wang, Feijun
Li, Yonghong
Guo, Bingyi
Yang, Zhonglin
Zuo, Yingying
Powiązania:
https://bibliotekanauki.pl/articles/27787917.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nitrate glycerol ether cellulose
NGEC
mechanical properties
compatibility
propellant
energy
Opis:
Nitrocellulose (NC) with a semi-rigid polymer chain is one of the typical traditional cellulose derivatives. Optimization of its mechanical properties is of great significance for improving the performance of NC-based propellants. The nitrate glycerol ether cellulose (NGEC) was prepared by introducing glycerol onto the unreacted, free hydroxyl groups on NC through a three-step process (alkalization, etherification, and nitration). The effects of both the nitration process and the degree of etherification on the NGEC nitrogen content were qualitatively explored. By adding NGEC into modified double-base propellant, a standard engine grain with a diameter of 50 mm was produced by adsorption, granulation, and screw extrusion. The heat of explosion, and other physical properties of NGEC were characterized and the variation in mechanical properties and performance after storage for 6 years was investigated. The results indicated that the sensitivity was improved, and the stability was slightly decreased on increasing the nitrogen content of NGEC. Compared with NC containing similar nitrogen levels, NGEC exhibited a slightly higher heat of explosion, similar compatibility, and lower sensitivity. Additionally, the solubility of NGEC in ethanol/ether exceeded 99.7%. Through branched-chain chemical modification, the glycerol ether played a significant role in achieving internal plasticization among the cellulose chains.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 4; 448--476
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of Two Novel Species of Chaenea (Ciliophora, Litostomatea): Chaenea paucistriata spec. nov. and C. sinica spec. nov.
Autorzy:
Fan, Xinpeng
Xu, Yuan
GU, Fukang
LI, Jiqiu
Al-Farraj, Saleh A.
Al-Rasheid, Khaled A. S.
Hu, Xiaozhong
Powiązania:
https://bibliotekanauki.pl/articles/763652.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Chaenea, ciliary pattern, identification key, marine ciliates, new species, taxonomy
Opis:
During faunistic studies of ciliates in coastal waters of Daya Bay and Bohai Bay, China, two previously unknown ciliates were discovered and investigated using standard taxonomic methods. Morphological comparative analyses revealed that they represent two novel species in the genus Chaenea. Chaenea paucistriata spec. nov. can be distinguished from its congeners by the following traits: body length in vivo about 180–250 µm; eight somatic kineties; dorsal brush rows 1–4 consisting of three, five, seven, and two dikinetids, respectively; rod-like extrusomes, 8 µm long; 63–94 macronuclei; cortical granules minute and colourless. Chaenea sinica spec. nov. differs from its congeners in having: body length in vivo about 140–240 µm; 17–21 somatic kineties; dorsal brush rows 1–4 consisting of 3–7, 10 or 11, 11–13, and 3–6 dikinetids, respectively; rod-like extrusomes about 6–8 µm long; 71–164 macronuclei. A key is presented to assist the identification of all Chaenea species.
Źródło:
Acta Protozoologica; 2015, 54, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dexamethasone inhibits U937 cell adhesion via the down-regulation of ROCK1 activity
Autorzy:
Liu, Dong
Chen, Xing
Xiong, Ren
Ning, Ya
Li, Ping
Peng, Yan
Liu, Ping
Zhao, Yan
Yang, Nan
Zhou, Yuan
Powiązania:
https://bibliotekanauki.pl/articles/1039650.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
dexamethasone
ROCK1
fasudil
non-genomic effects
Opis:
Objective. To explore the effect of dexamethasone (DEX) on monocyte adhesion function and its underlying mechanism. Methods. The effects of DEX and fasudil on adhesion of cultured U937 monocytes to human umbilical vein endothelial cells (HUVEC) following stimulation with phorbol myristate acetate (PMA) were studied; Changes in the Rho-associated coiled-coil protein kinase 1 (ROCK1) protein content and activity were evaluated. Results. DEX and fasudil significantly inhibited U937 cell adhesion rates under PMA stimulation and inhibited ROCK1 activity. Mifepristone (RU-486) and cycloheximide (CHX) did not alter these effects of DEX. Conclusions. DEX interferes with the adhesion function of U937 cells through the inhibition of ROCK1 activity.
Źródło:
Acta Biochimica Polonica; 2012, 59, 4; 557-560
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Real-time optical demultiplexing with the chirped pulses
Autorzy:
Li, Y.
Zhang, X.
Yuan, J.
Kang, Z.
Sang, X.
Kang, S.
Kang, X.
Yan, B.
Wang, K.
Yu, C.
Powiązania:
https://bibliotekanauki.pl/articles/175106.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
linearly chirped pulse
parametric process
real-time optical demultiplexing
Opis:
A scheme for real-time optical demultiplexing is proposed by utilizing the time-broadened and linearly chirped pulses instead of the conventional mode-locked pulses. The copies of the optical-time-division-multiplexed signal are acquired through a dual-pump parametric gate and used as the parametric multicast block. Simulation results show that the demultiplexing from 160 Gb/s down to sixteen 10 Gb/s tributaries can be achieved only by using a sampling source of 10 GHz. The proposed scheme can effectively reduce the complexity of parallel processing, and find important applications in the high-speed all-optical signal processing.
Źródło:
Optica Applicata; 2018, 48, 4; 621-632
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient phosphate removal in swine wastewatewater using Fe-Mn-modified pyro/hydrochar from swine manure
Autorzy:
Zhu, Fanglun
Zhang, Cheng
Shan, Shengdao
Yuan, Wenqiao
Pawłowski, Artur
Song, Chengfang
Cao, Yucheng
Li, Yongfu
Wangj, Junjie
Qian, Jinyao
Powiązania:
https://bibliotekanauki.pl/articles/2032865.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphate adsorption
pig
water eutrophication
biochar
swine manure
adsorpcja fosforanów
trzoda chlewna
eutrofizacja wód
biowęgiel
obornik świński
Opis:
Phosphorus in wastewater is one of the main causes of water eutrophication. Phosphorus removal from swine wastewater is always a challenge. To achieve on-site recycling of swine farm waste, the low-cost pyro/hydrochars and their Fe-Mn-modified form were prepared from swine manure as an efficient adsorbent for phosphate removal. The results showed that the phosphate removal efficiency of unmodified pyro/hydrochars was less than 7.77%, which was significantly increased to 58.21–83.76% for the Fe-Mn-modified-pyro/hydrochars. The maximum adsorption capacity of pyrochar was found on the Fe-Mn-modified-pyrochar (PC-600M) with a surface area of 102.03 m2/g and a micropore volume of 0.25 cm3/g. The PC-600M exhibited high adsorption capacity (26.07 mg/g) in a low concentration of phosphate (50 mg/dm3), and its removal efficiency reached up to 83.76% within 24 hours. Furthermore, the adsorption of phosphate on biochars without modification (HC-210 and PC-600) was validated using a first-order kinetic model, and the adsorption of phosphate on modified biochars (HC-210M and PC-600M) was well described by the second-order kinetic model and Langmuir isotherm. In addition, there is no significant difference in the adsorption of phosphorus between pyrochars and hydrochars, but the preparation cost of hydrochars is lower than that of pyrochars. It was confirmed that the low-cost Fe-Mn-modified pyro/hydrochar from swine manure had potential for efficient phosphate removal in wastewater treatment and would facilitate value-added utilization of swine manure.
Źródło:
Environment Protection Engineering; 2021, 47, 3; 83-101
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phyllodulcin Protects PC12 Cells Against the Injury Induced by Oxygen and Glucose Deprivation-Restoration
Autorzy:
Hu, Chang-Long
Ge, Lu
Tang, Yong
Li, Jie
Wu, Chun-Hui
Hu, Jiang-Hong
Yuan, Jin-Tao
Fan, Yong-Zhong
Powiązania:
https://bibliotekanauki.pl/articles/895391.pdf
Data publikacji:
2019-12-29
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
apoptosis
oxidative stress
PC12 cells
phyllodulcin
oxygen and glucose deprivation/restoration
Opis:
Phyllodulcin is a natural coumarin derivative found in Hydrangea macrophylla. To discover effective therapeutics for cerebral ischemia-reperfusion injury, we investigated the protective effects of phyllodulcin on PC12 cells injury induced by oxygenation and glucose deprivation/restoration (OGD/R). As a result, phyllodulcin can improve the cell viability and attenuate the extracellular lactate dehydrogenase release. Meanwhile, phyllodulcin can ameliorate the dysfunction of mitochondria through reducing reactive oxygen species production, decreasing the intracellular calcium level and increasing the mitochondrial membrane potential. ROS-associated OGD/R can induce cell apoptosis through the mitochondrial pathway. Phyllodulcin can inhibit apoptosis of PC12 cells through down-regulation of Caspase-3 and Bax as well as up-regulation of Bcl-2. These results indicate phyllodulcin can protect PC12 cells against the damage induced by OGD/R. This investigation gives promising evidences for the therapy of cerebral ischemia-reperfusion injury.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 6; 1043-1050
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of differential serum expression of three factors and pulmonary function in patients with silicosis
Autorzy:
Zhu, Ying
Duan, Xia Yu
Cheng, Yun Qi
Yao, Xin Jing
Xu, Hong
Zhang, Kui Sheng
Li, Feng Shi
Yang, Fang
Liu, Liang He
Yuan, Xiang Ju
Powiązania:
https://bibliotekanauki.pl/articles/2086531.pdf
Data publikacji:
2021-08-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
silicosis
pulmonary function
early diagnosis
ROC
PTPN2
factor B
Opis:
ObjectivesSilicosis is a chronic occupational lung disease. As was previously found by the authors, some proteins increased in the lung tissue of activated rats, and protein tyrosine phosphatase non-receptor type 2 (PTPN2), factor B, and vaccinia-related kinase 1 (VRK1) showed highly differential expressions.Material and MethodsIn this study, serum and bronchoalveolar lavage fluid samples were collected from patients with silicosis and healthy people to verify the expression of PTPN2, factor B, and VRK1. The diagnostic value of differentially expressed proteins for silicosis was judged.ResultsThe expression levels of serum PTPN2, VRK1, and factor B in patients with silicosis were significantly higher than those in the control group (p < 0.01). Higher serum PTPN2 and factor B concentrations significantly and negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), maximum vital capacity (VCmax), FEV1, and FVC, suggesting that the high expression of PTPN2 and factor B is associated with decreased pulmonary ventilation function and restrictive ventilatory impairment in patients with silicosis. All area under curve (AUC) measurements generated from single detection events were >0.744, with PTPN2 reaching the highest value (0.858). The AUC, sensitivity, and specificity for the combined diagnosis using factor B and PTPN2 were 0.907, 86.91% and 85.07%, respectively, for factor B and PTPN2. The 3 differentially expressed proteins are potential classes of predictive biomarkers for silicosis.ConclusionsRegarding the economy and test practicality, the best diagnostic combination is factor B and PTPN2 for the analysis of AUC, sensitivity and specificity.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 4; 527-540
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Element Analysis on Structural Behaviour of Geopolymer Reinforced Concrete Beam using Johnson-Cook Damage in ABAQUS
Autorzy:
Mortar, Nurul Aida Mohd
Al Bakri Abdullah, Mohd Mustafa
Hussin, Kamarudin
Razak, Rafiza Abdul
Hamat, Sanusi
Hilmi, Ahmad Humaizi
Shahedan, Noorfifi Natasha
Li, Long Yuan
Aziz, Ikmal Hakem A.
Powiązania:
https://bibliotekanauki.pl/articles/2174588.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fly ash geopolymer
geopolymer concrete
finite element analysis
Johnson Cook Damage
ABAQUS software
Opis:
This paper details a finite element analysis of the behaviour of Si-Al geopolymer concrete beam reinforced steel bar under an impulsive load and hyper velocity speed up to 1 km/s created by an air blast explosion. The initial torsion stiffness and ultimate torsion strength of the beam increased with increasing compressive strength and decreasing stirrup ratio. The study involves building a finite element model to detail the stress distribution and compute the level of damage, displacement, and cracks development on the geopolymer concrete reinforcement beam. This was done in ABAQUS, where a computational model of the finite element was used to determine the elasticity, plasticity, concrete tension damages, concrete damage plasticity, and the viability of the Johnson-Cook Damage method on the Si-Al geopolymer concrete. The results from the numerical simulation show that an increase in the load magnitude at the midspan of the beam leads to a percentage increase in the ultimate damage of the reinforced geopolymer beams failing in shear plastic deformation. The correlation between the numerical and experimental blasting results confirmed that the damage pattern accurately predicts the response of the steel reinforcement Si-Al geopolymer concrete beams, concluded that decreasing the scaled distance from 0.298 kg/m3 to 0.149 kg/m3 increased the deformation percentage.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1349--1354
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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