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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

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