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Friction and wear behavior and mechanism of low carbon microalloyed steel containing Nb

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China Foundry 2023年第3期20卷 263-270页

作者： Mei-yi yuan Jia-cheng Zhang yi-tao Yang School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Dry sliding friction and wear test of Nb containing low carbon microalloyed steel was carried out at room temperature,and the effect of Nb on the wear behavior of the steel,as welll as the mechanism was *** electron microscopy(SEM) and energy dispersive spectrometry(EDS) were employed to analyze the morphology and composition of the worn surface,and the structure evolution of the plastic deformation *** carbide content and type in the steel were analyzed by the electrolytic extraction device and X-ray diffraction(XRD).The experimental results demonstrate that the addition of 0.2% Nb can refine the grain and generate Nb C to improve the wear resistance of the *** enhancing the load and speed of wear experiment,the wear mechanism of the test steel with 0.2% Nb changes from slight oxidation wear to severe adhesion wear and oxidation *** with the load,the increase in the rotation speed exerts a greater influence on the wear of the test steel.

关键词： Nb content low carbon microalloyed steel friction and wear carbide

A thermoelectric generator and water-cooling assisted high conversion efficiency polycrystalline silicon photovoltaic system

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Frontiers in Energy 2021年第2期15卷 358-366页

作者： Zekun LIU Shuang yuan yi yuan Guojian LI Qiang WANG Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China Key Laboratory of Electromagnetic Processing of Materials of the Ministry of Education Northeastern UniversityShenyang 110819China

Solar energy has been increasing its share in the global energy structure. However, the thermal radiation brought by sunlight will attenuate the efficiency of solar cells. To reduce the temperature of the photovoltaic (PV) cell and improve the utilization efficiency of solar energy, a hybrid system composed of the PV cell, a thermoelectric generator (TEG), and a water-cooled plate (WCP) was manufactured. The WCP cannot only cool the PV cell, but also effectively generate additional electric energy with the TEG using the waste heat of the PV cell. The changes in the efficiency and power density of the hybrid system were obtained by real time monitoring. The thermal and electrical tests were performed at different irradiations and the same experiment temperature of 22°C. At a light intensity of 1000 W/m2, the steady-state temperature of the PV cell decreases from 86.8°C to 54.1°C, and the overall efficiency increases from 15.6% to 21.1%. At a light intensity of 800 W/m2, the steady-state temperature of the PV cell decreases from 70°C to 45.8°C, and the overall efficiency increases from 9.28% to 12.59%. At a light intensity of 400 W/m2, the steady-state temperature of the PV cell decreases from 38.5°C to 31.5°C, and the overall efficiency is approximately 3.8%, basically remain unchanged.

关键词： photovoltaic(PV) thermoelectric generator conversion efficiency hybrid energy systems water-cooled plate(WCP)

Preparation of a cationic azobenzene dye-montmorillonite intercalation compound and its photochemical behavior

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Journal of University of Science and Technology Beijing 2006年第3期13卷 281-286页

作者： Tao Wan yi yuan Wenqiong He College of Materials and Chemistry ＆ Chemical Engineering Chengdu University of Technology Chengdu 610059 China

Montmorillonite/cationic azobenzene dye （GTL） intercalation compounds were prepared by the conventional ion exchange method. As compared with that of pure GTL, the thermal stability of the intercalated GTL was greatly enhanced, and the absorption band corresponding to azobenzene group in intercalated GTL shifted towards a longer wavelength by 55 nm, which could be ascribed to the strong conjugation of GTL supramolecular order structure （J cluster） confined in a nanoscale space of montmorillonite interlayer gallery. The microstructures of the resulting intercalation compounds could be successfully controlled by varying the amount of dye loaded as evidenced by the basal spacing of the intercalation compounds. The intercalated azo dye in the montmorillonite interlayer space exhibited reversible trans-to-cis photoisomerization and thermal cis-to-trans reaction. FTIR proved the successful intercalation of GTL into the silicate layer.

关键词： Na-montmorillonite azobenzene intercalation photoisomerization

Seismic design analysis of the country masonry school buildings in the meizoseismal area

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Earthquake Engineering and Engineering Vibration 2011年第3期10卷 359-367页

作者： Feng yuan yi Dan Bi Qiong China Southwest Architecture Design ＆ Research Institute Chengdu 610042 China

Several reinforcing schemes are illustrated that are based on the loading characteristics of typical country masonry school buildings with sparsely spaced transversal walls and large depth. From the seismic damage observed following the Wenchuan Earthquake, the effects of reinforcing schemes, tie-columns and tie-beams on the seismic resistance of masonry buildings are analyzed. The concept of improving the ductility of these types of buildings is presented. Finally, some suggestions are proposed for the design of masonry buildings with sparsely spaced transversal walls and large depth.

关键词： masonry school buildings tie-columns tie-beams ductility wall between the windows Wenchuan earthquake seismic damage

Height Variation in the Summer Quasi-Zero Wind Layer over Dunhuang, Northwest China: A Diagnostic Study

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Journal of Meteorological Research 2022年第4期36卷 618-630页

作者： yi yuan yi LIU Lingkun RAN Hua ZHANG School of Environmental Studies China University of GeosciencesWuhan 430074 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081

This study investigates the variation in the stratospheric quasi-zero wind layer(QZWL)over Dunhuang,Gansu Province,China,on 9 August 2020 using sounding observations from the Dunhuang national reference station and the fifth generation of ECMWF atmospheric reanalysis data(ERA5).The QZWL over Dunhuang was located between 18.6 and 20.4 km on 9 August *** South Asian high(SAH)and subtropical westerly jet jointly affected the *** the SAH retreated westward,the upper-level westerly jet over Dunhuang strengthened,and the jet axis height *** a result,the zonal westerly wind was lifted to a higher altitude,and the wind speed of 100–70 hPa increased,raising the *** addition,the east–west oscillation of the SAH occurred earlier than the adjustment of the QZWL altitude,which can be used as a forecasting indicator for the *** further explore the mechanism responsible for the QZWL adjustment,the forcing terms in the equations for zonal wind,kinetic energy,and vertical wind shear were *** results showed that the upper-level geopotential gradient was the basic physical factor forcing the local change in zonal wind and kinetic *** change in zonal wind and kinetic energy led to the uplift of the *** results revealed that the vertical shear of horizontal wind could adequately indicate the stratospheric QZWL location.

关键词： stratospheric quasi-zero wind layer stratospheric airships South Asian high

Cultural Empathy and Its Cultivation in Cross-Cultural Communication

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学术界 2020年第7期 227-234页

作者： yuan yi School of Foreign Studies Shaanxi University of Technology Hanzhong Shaanxi 723001

With the continuous development of global integration and frequent exchanges between countries,heterogeneous cultural conflicts grow as a result.A good ability of cross-cultural communication is playing an important part in resolving these contradictions and *** empathy is an important factor of cross-cultural communication ability,and is the key factor to the smooth and successful cross-cultural *** empathy needs to follow the moderate principle—neither"missing"nor"excessive".This article discusses the connotation of cultural empathy from the basic connotation of cross-cultural communication,*** the principle of moderation will be helpful in multicultural communication across cultural differences through multi-channel cultivation and,with agreement to disagree,to achieve effective cross-cultural communication.

关键词： cross-cultural communication(CC) cultural empathy cultivation

A Note on the Lehmer Problem over Short Intervals

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Acta Mathematica Sinica,English Series 2011年第6期27卷 1115-1120页

作者： Ya Ming LU yuan yi School of Science Xi'an Jiaotong University Xi'an 710049 P. R. China

Let p be an odd prime, c be an integer with （c,p） = 1, and let N be a positive integer withN ≤ p - 1. Denote by r（N, c;p） the number of integers a satisfying 1 ≤ a ≤ N and 2 a ＋ a, where a is an integer with 1 ≤a≤ p - 1, aa ≡ c （mod p）. It is well known that r（N, c;p） = 1/2N ＋ O（p1/2log2p）.The main purpose of this paper is to give an asymptotic formula for ∑p-1 c=1（τ（N,c;p）-1/2N）2.

关键词： Lehmer problem character sum Dirichlet L-function

On the Generalization of the *** Problem

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Acta Mathematica Sinica,English Series 2009年第8期25卷 1269-1274页

作者： Ya Ming LU yuan yi Research Center for Basic Science Xi'an Jiaotong University Xi'an 710049 P. R. China

Let n ≥ 2 be a fixed positive integer, q ≥ 3 and c be two integers with （n, q） = （c, q） = 1. We denote by rn（51, 52, C; q）（δ 〈 δ1,δ2≤ 1） the number of all pairs of integers a, b satisfying ab ≡ c（mod q）, 1 〈 a ≤δ1q, 1 ≤ b≤δ2q, （a,q） = （b,q） = 1 and nt（a＋b）. The main purpose of this paper is to study the asymptotic properties of rn （δ1, δ2, c; q）, and give a sharp asymptotic formula for it.

关键词： D. H. Lehmer problem Gauss sum Kloosterman sum

Influence of seasonal temperature change on autotrophic nitrogen removal for mature landfill leachate treatment with high-ammonia by partial nitrification-Anammox process

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Journal of Environmental Sciences 2021年第4期33卷 291-300页

作者： Xiang Li Ming-yu Lu Yong Huang yi yuan Yan yuan School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology Suzhou 215009China

In this study,a denitrification(DN)–partial nitritation(PN)–anaerobic ammonia oxidation(Anammox)system for the efficient nitrogen removal of mature landfill leachate was built with a zone-partitioning self-reflux biological reactor as the core device,and the effects of changes in seasonal temperature on the nitrogen removal in non-temperature-control environment were *** results showed that as the seasonal temperature decreased from 34℃to 11.3℃,the total nitrogen removal rate of the DN-PN-Anammox system gradually decreased from the peak value of 1.42 kg/(m^(3)·day)to 0.49 kg/(m^(3)·day).At low temperatures(<20℃),when the nitrogen load(NLR)of the system is not appropriate,the fluctuation of high NH_(4)^(+)-N concentration in the landfill leachate greatly influenced the stability of the nitrogen *** temperatures of 11℃–15℃,the NLR of the system is controlled below 0.5 kg/(m^(3)·day),which can achieve stable nitrogen removal and the nitrogen removal efficiency can reach above 96%.The abundance of Candidatus Brocadia gradually increased with the decrease of ***,Candidatus Brocadia and Candidatus Kuenenia as the main functional microorganisms in the low temperature.

关键词： Landfill leachate Denitrification-partial nitrification-Anammox Seasonal temperature Nitrogen removal Microbiology community