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Tytuł:
Occupational daily walking steps have inverse relationship with papillary thyroid cancer risk and progression: a retrospective analysis
Autorzy:
Zhang, Chunling
Zhang, Li
Su, Yan
Xiang, Lei
Zhang, Qin
Zhang, Chunhong
Huan, Qin
Powiązania:
https://bibliotekanauki.pl/articles/28761990.pdf
Data publikacji:
2024-03-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
biochemical markers
office workers
construction workers
papillary thyroid cancer
daily step counts
PTC stages
Opis:
Objectives Investigate the impact of daily occupational walking steps on the progression of papillary thyroid cancer (PTC), a topic hitherto underresearched. Material and Methods The authors analyzed the data from 800 individuals with PTC across stages 0–IV. Participants were evenly divided into 2 distinct occupational groups: office workers and construction workers (N = 400 each). Data included comprehensive records of daily walking steps, demographic information, and clinical indicators. Pearson’s correlation coefficients or analysis of variance (ANOVA) were employed to assess the linkage between daily walking steps and PTC risk and stage, as well as associated biochemical markers. Results The analysis revealed a significant inverse relationship between daily walking steps and PTC risk. A higher frequency of daily steps was associated with reduced chances of PTC onset and a lower diagnostic stage of the disease. This protective effect of physical activity was particularly pronounced in the construction worker cohort. Subsequent evaluations showed that construction workers who consistently logged higher daily steps had markedly lower levels of thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, thyroid peroxidase antibody, thyroglobulin antibody, and thyroglobulin (Tg). Notably, daily walking steps exhibited a strong inverse correlation with body mass index (BMI), age, PTC volumes, and levels of TSH and Tg across both occupational groups (ρ < –0.37). The increase in daily steps was associated with the reduction in PTC stages (p < 0.001). Conclusions The research underscores the potential benefits of increased daily walking steps, suggesting that they may play a protective role in reducing PTC risk and moderating its progression.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2024, 37, 1; 58-71
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A BIM technology-based underwater structure damage identification and management method
Autorzy:
Li, Xiaofei
Su, Rongrong
Cheng, Peng
Sun, Heming
Meng, Qinghang
Song, Taiyi
Wei, Mengpu
Zhang, Chen
Powiązania:
https://bibliotekanauki.pl/articles/2204531.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
building information modeling
underwater structural disease
damage identification
deep learning
modelowanie informacji o budynku
identyfikacja uszkodzeń
uczenie głębokie
uszkodzenie podwodnej konstrukcji
Opis:
With the continuous development of bridge technology, the condition assessment of large bridges has gradually attracted attention. Structural Health Monitoring (SHM) technology provides valuable information about a structure's existing health, keeping it safe and uninterrupted use under various operating conditions by mitigating risks and hazards on time. At the same time, the problem of bridge underwater structure disease is becoming more obvious, affecting the safe operation of the bridge structure. It is necessary to test the bridge’s underwater structure. This paper develops a bridge underwater structure health monitoring system by combining building information modeling (BIM) and an underwater structure damage algorithm. This paper is verified by multiple image recognition networks, and compared with the advantages of different networks, the YOLOV4 network is used as the main body to improve, and a lightweight convolutional neural network (Lite-yolov4) is built. At the same time, the accuracy of disease identification and the performance of each network are tested in various experimental environments, and the reliability of the underwater structure detection link is verified.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 2; art. no. e144602
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Fault Diagnosis of Highway Bi-LSTM Based on Attention Mechanism
Autorzy:
Li, Xueyi
Su, Kaiyu
He, Qiushi
Wang, Xiangkai
Xie, Zhijie
Powiązania:
https://bibliotekanauki.pl/articles/24200832.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
fault diagnosis
Bi-LSTM
attention
highway
deep learning
Ball Bearing
Opis:
Deep groove ball bearings are widely used in rotary machinery. Accurate for bearing faults diagnosis is essential for equipment maintenance. For common depth learning methods, the feature extraction of inverse time domain signal direction and the attention to key features are usually ignored. Based on the long short term memory(LSTM) network, this study proposes an attention-based highway bidirectional long short term memory (AHBi-LSTM) network for fault diagnosis based on the raw vibration signal. By increasing the Attention mechanism and Highway, the ability of the network to extract features is increased. The bidirectional LSTM network simultaneously extracts the raw vibration signal in positive and inverse time-domains to better extract the fault features. Six deep groove ball bearings with different health conditions were used to validate the AHBi-LSTM method in an experiment. The results showed that the accuracy of the proposed method for bearing fault diagnosis was over 98%, which was 8.66% higher than that of the LSTM model. The AHBi-LSTM model is also better than other relevant models for bearing fault diagnosis.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 2; art. no. 162937
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust dual color images watermarking scheme with hyperchaotic encryption based on quaternion DFrAT and genetic algorithm
Autorzy:
Luo, Hui-Xin
Gong, Li-Hua
Chen, Su-Hua
Powiązania:
https://bibliotekanauki.pl/articles/27310094.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
color image watermarking
hyperchaotic encryption
quaternion discrete fractional angular transform
quaternion singular value decomposition
genetic algorithm
Opis:
A robust dual color images watermarking algorithm is designed based on quaternion discrete fractional angular transform (QDFrAT) and genetic algorithm. To guarantee the watermark security, the original color watermark image is encrypted with a 4D hyperchaotic system. A pure quaternion matrix is acquired by performing the discrete wavelet transform (DWT), the block division and the discrete cosine transform on the original color cover image. The quaternion matrix is operated by the QDFrAT to improve the robustness and the security of the watermarking scheme with the optimal transform angle and the fractional order. Then the singular value matrix is obtained by the quaternion singular value decomposition (QSVD) to further enhance the scheme’s stability. The encryption watermark is also processed by DWT and QSVD. Afterward, the singular value matrix of the encryption watermark is embedded into the singular value matrix of the host image by the optimal scaling factor. Moreover, the values to balance imperceptibility and robustness are optimized with a genetic algorithm. It is shown that the proposed color image watermarking scheme performs well in imperceptibility, security, robustness and embedding capacity.
Źródło:
Optica Applicata; 2023, 53, 2; 261--280
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Double-image encryption algorithm based on discrete fractional angular transform and fractional Fourier transform
Autorzy:
Qiu, Tian
Dai, Wei-Hua
Chen, Su-Hua
Zhou, Hang
Gong, Li-Hua
Powiązania:
https://bibliotekanauki.pl/articles/2172857.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chaotic system
fractional transform
discrete fractional angular transform
double-image encryption
Opis:
By combining fractional Fourier transform with discrete fractional angular transform, a double-image encryption algorithm is designed. The discrete cosine transform is performed on two grayscale images to generate a spectrum image, and then the generated spectrum image is compressed into an image with Zigzag scanning. The compressed image is processed with the discrete fractional angular transform, and then fractional Fourier transform and double random phase coding are executed on the image. The DNA operation controlled by chaotic system is introduced to change the pixel values. Finally, the ciphertext image is obtained through bit-level permutation and pixel adaptive diffusion. The statistical information of the plaintext images is employed as the input of the SHA-256 to calculate the initial conditions of the chaotic map. Simulation experiments demonstrate that the double-image encryption algorithm can effectively reduce the correlation among adjacent pixels of the plaintext images.
Źródło:
Optica Applicata; 2022, 52, 4; 669--684
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency Evaluation and Influencing Factors of Government Financial Expenditure on Environmental Protection: An SBM Super-efficiency Model Based on Undesired Outputs
Ocena efektywności i czynniki wpływające na rządowe wydatki finansowe na ochronę środowiska: model Super-efektywności SBM oparty na niepożądanych efektach
Autorzy:
Jialu, Su
Zhiqiang, Ma
Mingxing, Li
Agyeman, Fredrick Oteng
Yue, Zhu
Powiązania:
https://bibliotekanauki.pl/articles/2073438.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
efficiency of government expenditure on environmental protection
unexpected output
SBM super efficiency model
influence factor
efektywność wydatków rządowych na ochronę środowiska
nieoczekiwane wyniki
model super efektywności SBM
współczynniki wpływu
Opis:
In recent years, the adoption of the precise approach for coordinating socio-economic growth and environmental protection to attain sustainable development has become an urgent challenge to be addressed in China. The current development of environmental governance and the efficiency of government financial expenditure on environmental protection (EPEE) deserves enormous attention. With the aid of the provincial panel data, this study emphasized on the use of the SBM super-efficiency model based on unexpected output to quantify the efficiency of China’s government expenditure on environmental protection from 2013-2018 and constructed the Ordinary Least Squares (OLS) regression model to investigate the influencing factors of the government expenditure on environmental protection. The results of the efficiency measurement portray that the aggregate EPEE in China is unsatisfactory. The efficiency value for the western region is greater than that of the central and eastern regions, while the values obtained from the eastern region are above that of the central region. Population size and urbanization level have negative implications on the efficiency value, while the regional economic development level positively promotes the efficiency of the government expenditure on environmental protection. Finally, the corresponding countermeasures and suggestions for policy implementation are outlined accordingly.
W ostatnich latach przyjęcie precyzyjnego podejścia do koordynacji wzrostu społeczno-gospodarczego i ochrony środowiska w celu osiągnięcia zrównoważonego rozwoju stało się pilnym zadaniem w Chinach. Na ogromną uwagę zasługuje obecny rozwój zarządzania środowiskiem oraz efektywność rządowych nakładów finansowych na ochronę środowiska (EPEE). Z pomocą danych panelowych z prowincji, badanie to kładło nacisk na wykorzystanie modelu super-wydajności SBM opartego na nieoczekiwanych wynikach do ilościowego określenia wydajności chińskich wydatków rządowych na ochronę środowiska w latach 2013-2018. Skonstruowano kwadraty (OLS) modelu regresji do badania czynników wpływających na wydatki rządowe na ochronę środowiska. Wyniki pomiaru efektywności pokazują, że zagregowany EPEE w Chinach jest niezadowalający. Wartość efektywności dla regionu zachodniego jest większa niż w regionach centralnych i wschodnich, podczas gdy wartości uzyskane z regionu wschodniego są wyższe niż w regionie centralnym. Negatywnie na wartość efektywności wpływa wielkość populacji i poziom urbanizacji, natomiast regionalny poziom rozwoju gospodarczego pozytywnie wpływa na efektywność wydatków rządowych na ochronę środowiska. Na koniec nakreślono możliwe sposoby poprawy sytuacji i sugestie dotyczące wdrażania polityki.
Źródło:
Problemy Ekorozwoju; 2022, 17, 1; 140--150
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New approach to spindle thermal extension measuring based on machine vision for the vertical maching centre
Autorzy:
Su, Dongxu
Cai, Xin
Li, Yang
Zhao, Wanhuan
Zhang, Huijie
Powiązania:
https://bibliotekanauki.pl/articles/1849108.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Spindle thermal extension measuring
machine vision
Gaussian sub-pixel fitting
thermal error compensation
Opis:
When machine tool spindles are running at a high rotation speed, thermal deformation will be introduced due to the generation of large amounts of heat, and machining accuracy will be influenced as a result, which is a generalized issue in numerous industries. In this paper, a new approach based on machine vision is presented for measurements of spindle thermal error. The measuring system is composed of a Complementary Metal-Oxide-Semiconductor (CMOS) camera, a backlight source and a PC. Images are captured at different rotation angles during end milling process. Meanwhile, the Canny edge detection and Gaussian sub-pixel fitting methods are applied to obtain the bottom edge of the end mill which is then used to calculate the lowest point coordinate of the tool. Finally, thermal extension of the spindle is obtained according to the change of the lowest point at different time steps of the machining process. This method is validated through comparison with experimental results from capacitive displacement sensors. Moreover, spindle thermal extension during the processing can be precisely measured and used for compensation in order to improve machining accuracy through the proposed method.
Źródło:
Metrology and Measurement Systems; 2021, 28, 2; 357-370
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Organ-level evaluation of the carbon starvation hypothesis in deciduous broad-leaved Catalpa bungei plants undergoing drought-induced mortality
Autorzy:
Qiu, Q.
Wang, J.
Su, Y.
Li, J.
Ma, J.
He, Q.
Powiązania:
https://bibliotekanauki.pl/articles/2078283.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Carbon starvation
Catalpa bungei
Drought
Non-structural carbohydrate (NSC)
Plant mortal-
ity
Opis:
The carbon starvation hypothesis (CSH) is one of the current leading hypotheses regarding the mechanism of plant death, although it has not been sufficiently validated due to a lack of evidence. To help verify the role of carbon starvation in plant mortality, we measured the non-structural carbohydrate (NSC) concentration ([NSC]) in different organs (roots, stems, and leaves) of plants of Catlapa bungei clone 9-1 after the cessation of photosynthesis and death due to drought and in well-watered controls. Drought in- duced the loss of NSC reserves, which was observed in all organs at death, and carbon starvation appeared to begin after the cessation of photosynthesis. The [NSC] dynamics, occurrence time of carbon starvation, and survival time varied among the organs, and even within the same organs at different stem heights. Overall, our findings are compatible with the CSH in that carbon starvation occurs in roots, stems, and leaves and concurs with plant death during prolonged drought.
Źródło:
Dendrobiology; 2018, 80; 48-60
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and Analysis of Sintering Furnace Temperature Based on Fuzzy Neural Network Control
Autorzy:
Chaoxin, Zou
Rong, Li
Zhiping, Xie
Ming, Su
Jingshi, Zeng
Xu, Ji
Xiaoli, Ye
Ye, Wang
Powiązania:
https://bibliotekanauki.pl/articles/1837792.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuzzy neural network
furnace
sintering
temperature control
PID
sieć neuronowa rozmyta
piec
spiekanie
kontrola temperatury
Opis:
Aiming at the problems of delay and couple in the sintering temperature control system of lithium batteries, a fuzzy neural network controller that can solve complex nonlinear temperature control is designed in this paper. The influence of heating voltage, air inlet speed and air inlet volume on the control of temperature of lithium battery sintering is analyzed, and a fuzzy control system by using MATLAB toolbox is established. And on this basis, a fuzzy neural network controller is designed, and then a PID control system and a fuzzy neural network control system are established through SIMULINK. The simulation shows that the response time of the fuzzy neural network control system compared with the PID control system is shortened by 24s, the system stability adjustment time is shortened by 160s, and the maximum overshoot is reduced by 6.1%. The research results show that the fuzzy neural network control system can not only realize the adjustment of lithium battery sintering temperature control faster, but also has strong adaptability, fault tolerance and anti-interference ability.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 23-30
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and Analysis of Sintering Furnace Temperature Based on Fuzzy Neural Network Control
Autorzy:
Chaoxin, Zou
Rong, Li
Zhiping, Xie
Ming, Su
Jingshi, Zeng
Xu, Ji
Xiaoli, Ye
Ye, Wang
Powiązania:
https://bibliotekanauki.pl/articles/1837849.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuzzy neural network
furnace
sintering
temperature control
PID
sieć neuronowa rozmyta
piec
spiekanie
kontrola temperatury
Opis:
Aiming at the problems of delay and couple in the sintering temperature control system of lithium batteries, a fuzzy neural network controller that can solve complex nonlinear temperature control is designed in this paper. The influence of heating voltage, air inlet speed and air inlet volume on the control of temperature of lithium battery sintering is analyzed, and a fuzzy control system by using MATLAB toolbox is established. And on this basis, a fuzzy neural network controller is designed, and then a PID control system and a fuzzy neural network control system are established through SIMULINK. The simulation shows that the response time of the fuzzy neural network control system compared with the PID control system is shortened by 24s, the system stability adjustment time is shortened by 160s, and the maximum overshoot is reduced by 6.1%. The research results show that the fuzzy neural network control system can not only realize the adjustment of lithium battery sintering temperature control faster, but also has strong adaptability, fault tolerance and anti-interference ability.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 23-30
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation studies on the influence of other combustible gases on the characteristics of methane explosions at constant volume and high temperature
Autorzy:
Luo, Zhenmin
Liu, Litao
Gao, Shuaishuai
Wang, Tao
Su, Bin
Wang, Lei
Yang, Yong
Li, Xiufang
Powiązania:
https://bibliotekanauki.pl/articles/1853863.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gaz palny
ciśnienie wybuchu
temperatura płomienia
constant volume
volume fraction of combustible gas
initial temperature
adiabatic flame temperature
maximum explosion pressure
Opis:
Gas explosions are major disasters in coal mining, and they typically cause a large number of deaths, injuries and property losses. An appropriate understanding of the effects of combustible gases on the characteristics of methane explosions is essential to prevent and control methane explosions. FLACS software was used to simulate an explosion of a mixture of CH4 and combustible gases (C2H4, C2H6, H2, and CO) at various mixing concentrations and different temperatures (25, 60, 100, 140 and 180℃). After adding combustible gases to methane at a constant volume and atmospheric pressure, the adiabatic flame temperature linearly increases as the initial temperature increases. Under stoichiometric conditions (9.5% CH4-air mixture), the addition of C2H4 and C2H6 has a greater effect on the adiabatic flame temperature of methane than H2 and CO at different initial temperatures. Under the fuel-lean CH4-air mixture (7% CH4-air mixture) and fuel-rich mixture (11% CH4-air mixture), the addition of H2 and CO has a greater effect on the adiabatic flame temperature of methane. In contrast, the addition of combustible gases negatively affected the maximum explosion pressure of the CH4-air mixture, exhibiting a linearly decreasing trend with increasing initial temperature. As the volume fraction of the mixed gas increases, the adiabatic flame temperature and maximum explosion pressure of the stoichiometric conditions increase. In contrast, under the fuel-rich mixture, the combustible gas slightly lowered the adiabatic flame temperature and the maximum explosion pressure. When the initial temperature was 140℃, the fuel consumption time was approximately 8-10 ms earlier than that at the initial temperature of 25℃. When the volume fraction of the combustible gas was 2.0%, the consumption time of fuel reduced by approximately 10 ms compared with that observed when the volume fraction of flammable gas was 0.4%.
Źródło:
Archives of Mining Sciences; 2021, 66, 2; 279-295
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical and experimental study of marine hydrogen–natural gas–diesel tri–fuel engines
Autorzy:
Zhao, Rui
Xu, Leping
Su, Xiangwen
Feng, Shiquan
Li, Changxiong
Tan, Qinming
Wang, Zhongcheng
Powiązania:
https://bibliotekanauki.pl/articles/1573839.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
hydrogen
tri-fuel engine
combustion performance
emission performance
Opis:
Maritime shipping is a key component of the global economy, representing 80–90% of international trade. To deal with the energy crisis and marine environmental pollution, hydrogen-natural gas-diesel tri-fuel engines have become an attractive option for use in the maritime industry. In this study, numerical simulations and experimental tests were used to evaluate the effects of different hydrogen ratios on the combustion and emissions from these engines. The results show that, in terms of combustion performance, as the hydrogen proportion increases, the combustion ignition delay time in the cylinder decreases and the laminar flame speed increases. The pressure and temperature in the cylinder increase and the temperature field distribution expands more rapidly with a higher hydrogen ratio. This means that the tri-fuel engine (H2 +CH4 +Diesel) has a faster response and better power performance than the dual-fuel engine (CH4 +Diesel). In terms of emission performance, as the hydrogen proportion increases, the NO emissions increase, and CO and CO2 emissions decrease. If factors such as methane escape into the atmosphere from the engine are considered, the contribution of marine tri-fuel engines to reducing ship exhaust emissions will be even more significant. Therefore, this study shows that marine hydrogen-natural gas-diesel tri-fuel engines have significant application and research prospects.
Źródło:
Polish Maritime Research; 2020, 4; 80-90
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Al-Cu Cast Alloy Composition for Hydraulic Valves
Autorzy:
Li, Rong
Chen, Lunjun
Zeng, Qi
Su, Ming
Xie, Zhiping
Powiązania:
https://bibliotekanauki.pl/articles/381745.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Cu alloy
optimization
strengthening mechanisms
hydraulic multi-way valve
stop Al-Cu
optymalizacja
mechanizm wzmacniający
zawór hydrauliczny
Opis:
In order to identify the influence of different Mn, Cd, V and Zr content on the properties of Al-Cu casting alloys in hydraulic valves, orthogonal test methods were used to prepare alloy test bars with different elements and contents. Tensile tests were performed on the test bars so obtained. The microstructure of alloys with different compositions is studied. The results show that adding approximately 0.4% of Mn can not only form a strengthening phase but also reduce the excessive segregation of the matrix along the grain boundary. A Cd content of 0.2% can promote the formation of micro Cd spheres in the softer aluminum matrix. Hard spots increase the wear resistance of the material; however, an excess of Cd will cause element segregation and deteriorate the mechanical properties of the valve body. Zr and V refine the grains in the alloy; however, an excess of these elements will lead to a large area of segregation. If proper heat treatment is lacking, the mechanical properties of the valve body deteriorate.
Źródło:
Archives of Foundry Engineering; 2020, 20, 1; 84-94
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the X-ray wavelength division multiplexing technology for blackout region communication
Autorzy:
Li, Yao
Su, Tong
Sheng, Lizhi
Xu, Neng
Zhao, Baosheng
Powiązania:
https://bibliotekanauki.pl/articles/1835966.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
X-ray communication
plasma sheath
wavelength division multiplexing
Opis:
After the concept of X-ray communication was proposed, its application in complex electromagnetic environment has received more attention, such as data transmission in re-enter special electro-magnetic condition. In this article, a new type of X-ray source was introduced firstly, which was expected to generate multiple characteristic lines and achieve wavelength division multiplexing technology in X-ray band. Then an experimental platform was built for analyzing transmission characteristics of X-ray photon in various plasma media. Finally, the calculation model for a link power equation was given. Experiment results show that transmittance of 8–18 keV X-ray signal is relatively stable, atomic numbers from 29 to 42 are the most suitable materials for wavelength division multiplexing, the X-ray communication system is expected to realize about 200 kbps data transmission rate in adjacent space.
Źródło:
Optica Applicata; 2020, 50, 4; 619-632
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the Structure and Properties of Continuous Basalt Fibres
Badanie struktury i właściwości ciągłych włókien bazaltowych
Autorzy:
Shi, Fengjun
Su, Hang
Zhao, Lei
Yu, Xiuyan
Li, Shengxian
Powiązania:
https://bibliotekanauki.pl/articles/232546.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
basalt fibre
composition
property
włókno bazaltowe
skład
właściwości
Opis:
The chemical composition, X-ray diffraction, thermal properties, flammability, mechanical properties and morphology of basalt fibres are investigated in this paper. Chemical analysis and energy dispersive X-ray fluorescence spectrometer experiments showed that basalt fibre is a kind of aluminosillicate fibre which is mainly composed of oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, P2O5 and so on. X-ray diffraction indicated that the bulk structure of the fibres is non-crystal with a short range order but no long range order. SEM observation found that basalt fibre is circular in cross-section and smooth in the longitudinal direction. Solubility experiments revealed the superior resistance of the fibre to acids, alkaline and organic solvents. DGA demonstrated there are three weight loss stages in the process of elevating temperature. They are, respectively, evaporation of moisture in the fibre at about 100 °C, decomposition of the residual carbonate minerals between 480 °C and 630 °C, and decomposition of newly generated carbonates between 850~995 °C. On the heat flow curve, there are also three endothermic peaks, where the first and second correspond to the last two stages of weight loss and the third to the melting process of the fibre, whose onset is from 1122.14 °C, reaching a peak value at 1194.96 °C, and ending at 1380 °C. The tensile strength of basalt filaments and staple fibre was measured. Tensile and shear properties of the fibre were also tested.
W pracy zbadano skład chemiczny, dyfrakcję promieniowania rentgenowskiego, właściwości termiczne, łatwopalność, właściwości mechaniczne i morfologię włókien bazaltowych. Analiza chemiczna i eksperymenty ze spektrometrem rentgenowskim z dyspersją energii wykazały, że włókno bazaltowe jest rodzajem włókna glinokrzemianowego, które składa się głównie z tlenków, takich jak SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, P2O5, itd. Dyfrakcja rentgenowska wykazała, że struktura objętościowa włókien jest niekrystaliczna z uporządkowaniem bliskiego zasięgu, ale bez uporządkowania dalekiego zasięgu. Obserwacja SEM wykazała, że włókno bazaltowe ma kołowy przekrój poprzeczny i gładki w kierunku wzdłużnym. Eksperymenty z rozpuszczalnością wykazały lepszą odporność włókna na kwasy, zasady i rozpuszczalniki organiczne. DGA wykazało, że istnieją trzy etapy utraty masy w procesie podwyższania temperatury. Są to, odpowiednio: odparowanie wilgoci we włóknie w temperaturze około 100 °C, rozkład resztkowych minerałów węglanowych w przedziale 480-630 °C oraz rozkład nowo wytworzonych węglanów w przedziale 850-995 °C. Na krzywej przepływu ciepła występują również trzy endotermiczne piki, przy czym pierwszy i drugi odpowiadają ostatnim dwóm etapom utraty masy, a trzeci proces topienia włókna, którego początek wynosi od 1122,14 °C, osiągając wartość szczytową przy 1194,96 °C, a kończąc na 1380 °C. Zbadano także wytrzymałość na rozciąganie włókien bazaltowych.
Źródło:
Fibres & Textiles in Eastern Europe; 2020, 4 (142); 52-56
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 31

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