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Deformation Behavior of Medium-strength TA18 High-pressure Tubes During NC Bending with Different Bending Radii

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Chinese Journal of Aeronautics 2011年第5期24卷 657-664页

作者： JIANG Zhiqiang ZHAN Mei YANG He XU Xudong LI Guangjun School of Materials Science and Engineering State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi ＇an 710072 China Chengdu Aircraft industry （Group） Corporation Ltd. Chengdu 610092 China

To improve the forming quality and forming limit of the numerical control （NC） bending of high-pressure titanium alloy tubes, in this study, using three-dimensional （3D） finite element method, deformation behavior of medium-strength TA 18 high-pressure tubes during NC bending with different bending radii is investigated. The results show that the cross-sectional deformation and the wall thickness variation during NC bending of TA18 tubes using a small bending radius （less than 2 times of tube outside diameter） are clearly different from that using a normal bending radius （between 2 and 4 times of tube outside diameter）. For bending with a normal bending radius, with or without a mandrel, the distribution of the flattening in the bending area resembles a platform and an asymmetric parabola, respectively. For bending with a small bending radius, with or without a mandrel, the flattening both distributes like a parabola, but the former has a stable peak which deflects toward the initial bending section, and the latter has a more pronounced peak with a bending angle and deflects slightly toward the bending section. The wall thickness variations with a normal bending radius, with and without a mandrel, both resemble a platform when the bending angle exceeds a certain angle. For the bending with a small radius, the distribution of the wall thickness variation without a mandrel follows an approximate parabola which increases in value as the bending angle increases. If a mandrel is used, the thickening ratio increases from the initial bending section to the bending section.

关键词： titanium alloy tubes deformation behaviors numerical control bending finite element method normal bending radius small bending radius

Effect of Water Vapor Absorption on Measurements of Atmospheric Nitrate Radical by LP-DOAS

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Chinese Journal of Chemical Physics 2008年第5期21卷 433-437页

作者： Su-wen Li Wen-qing Liu Pin-hua Xie Yi-jun Yang De-bao Chen Zheng Li Department of Physics Huaibei Coal Industry Teachers College Huaibei 235000 China Key Laboratory of Environmental Optical and Technology Anhui Institute of Optics and Fine Me-chanics Chinese Academy of Sciences Hefei 230031 China

During the measurement of atmospheric nitrate radical by long-path differential optical absorption spectroscopy, water vapor strong absorption could affect the measurement of nitrate radical and detection limits of system. Under the tropospheric condition, the optical density of water vapor absorption is non-linearly dependent on column density. An effective method was developed to eliminate the effect of water vapor absorption. Reference spectra of water vapor based on the daytime atmospheric absorption spectra, when fitted together with change of cross section with water vapor column densities, gave a more accurate fitting of water vapor absorptions, thus its effect on the measurements of nitrate radical could be restricted to a minimum and detection limits of system reached 3.6 ppt. The modified method was applied during an intensive field campaign in the Pearl River Delta, China. The NO3 concentration in polluted air masses varied from 3.6 ppt to 82.5 ppt with an average level of 23.6±1.8 ppt.

关键词： Nitrate radical Water vapor absorption Long-path differential optical absorption spectroscopy Detection limit

What will happen in patients with advanced nonalcoholic fatty liver disease?

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Hepatobiliary Surgery and Nutrition 2019年第3期8卷 283-285页

作者： Takefumi Kimura Naoki Tanaka Eiji Tanaka Molecular Signaling section Laboratory of Bioorganic ChemistryNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA Department of Internal Medicine Division of GastroenterologyShinshu University School of MedicineMatsumotoJapan Department of Metabolic Regulation Shinshu University School of MedicineMatsumotoJapan International Research Center for Agricultural Food industry Shinshu UniversityMatsumotoJapan

Non-alcoholic fatty liver disease(NAFLD)and advanced form non-alcoholic steatohepatitis(NASH)have been become globally major chronic liver diseases(1,2).NAFLD is one of the leading causes of liver cirrhosis,hepatic failure,and hepatocellular carcinoma(HCC)(3).A large number of retrospective studies reported the importance of hepatic fibrosis with NAFLD patients as the strongest factor of liver-related mortality(4,5).On the other hand,NAFLD patients with advanced hepatic fibrosis are thought to have higer risk of developing vascular events and extrahepatic cancers because of the high prevalence of coexisting cardiometabolic risk factors,such as hypertension,diabetes mellitus,dyslipidemia,and obesity(6).However,since former literatures included only few NAFLD patients with advanced hepatic fibrosis,it is hard to estimate the accurate risk on the whole spectrum of these complications.

关键词： patients hepatic NAFLD

Effects of Optimized Operating Parameters on Combustion Characteristics and NO_(x)Emissions of a Burner based on Orthogonal Analysis

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Journal of Thermal Science 2021年第4期30卷 1212-1223页

作者： XU Qian AKKURT Nevzat YANG Gang ZHU Lidong SHI Kejian WANG Kang ZOU Zhenwei LIU Zhihui WANG Jiulong DU Zhiwei School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory for Energy Conservation and Emission Reduction for Metallurgical industry Beijing 100083China Department of Mechanical Engineering Munzur UniversityTunceli 62000Turkey Department of Big Data Technology and Application Development Computer Network Information CenterChinese Academy of SciencesBeijing 100190China AVIC Xinxiang Aviation industry(group)CO. LTDHenan 453002China

To optimize the structure of the burner,improve the combustion performance,and reduce the emission of NO_(x),a self-circulating low NO_(x)combustion technology was used to design a new type of flue gas self-circulating low NO_(x)*** on previous research on the numerical model of combustion and the composition of mixed gas on combustion and NO_(x)emissions,the effect of various factors on the ejection coefficient of the flue gas self-circulating structure was analyzed using the orthogonal test method,and the burner operating parameters,such as preheating temperature and excess air coefficient,were deeply studied through the three-dimensional finite element numerical model in this *** results show that the diameter ratio of the nozzle and the length of the cylindrical section of the flue gas self-circulating structure have great influence on its ejection and mixing *** optimal ejection coefficient was ***,the amount of NO_(x)emissions greatly increased from 6.23×10^(-6)(volume fraction)at the preheating temperature 973 K to 3.5×10^(-3)at preheating temperature 1573 *** the excess air coefficient decreased from 1.2 to 1,the maximum combustion temperature decreased from 2036.3 K to 1954.22 K,and the NO_(x)emissions decreased from 352.29×10^(-6)to 159.73×10^(-6).

关键词： preheating temperature excess air coefficient self-circulating flue gas low oxygen combustion low-NO_(x)emissions

Improvement and performance of parallel multilevel fast multipole algorithm

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Journal of Systems Engineering and Electronics 2011年第1期22卷 164-169页

作者： Zhanhe Liu Peilin Huang Zhe Wu Xu Gao School of Aeronautic Science and Engineering Beihang University Beijing 100191 P. R. China The First Aircraft Institute Aviation Industry Corporation of China Xi'an 710089 E R. China

The method of establishing data structures plays an important role in the efficiency of parallel multilevel fast multipole algorithm（PMLFMA）.Considering the main complements of multilevel fast multipole algorithm（MLFMA） memory,a new parallelization strategy and a modified data octree construction scheme are proposed to further reduce communication in order to improve parallel *** far interaction,a new scheme called dynamic memory allocation is *** analyze the workload balancing performance of a parallel implementation,the original concept of workload balancing factor is introduced and verified by numerical *** results show that the above measures improve the parallel efficiency and are suitable for the analysis of electrical large-scale scattering objects.

关键词： multilevel fast multipole algorithm(MLFMA) electromagnetic scattering parallelization radar cross section(RCS).

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最近国际环境会议动向

世界环境 1989年第4期 14-17页

作者： Shinjiro Tsuge 张有余 Pollution Control section Pollution Dept.Ministry of Trade and IndustryJapan

1.引言近年,CO2等造成的温室效应、氟里昂造成的臭氧层破坏、热带雨林的减少、沙漠化、酸雨、危险废物的越境迁移等问题越来越突出,这些问题不仅限于一国之内,而且是可以超越国界对全球环境产生深远影响的问题。由于全球环境问题规模之... 详细信息

1.引言近年,CO2等造成的温室效应、氟里昂造成的臭氧层破坏、热带雨林的减少、沙漠化、酸雨、危险废物的越境迁移等问题越来越突出,这些问题不仅限于一国之内,而且是可以超越国界对全球环境产生深远影响的问题。由于全球环境问题规模之大,影响之广涉及全球,因而是各国有识之士团结起来共同努力解决的问题,过去在高级首脑会议上也曾提出过各国政府相互配合处理此问题的重要性。本文拟对这些全球环境问题的概况及国际会议动向作一简介。

关键词：环境会议全球环境臭氧层破坏首脑会议蒙特利尔议定书气候变化氟里昂极地地区世界气候 UNEP

Spectral-furcated vector soliton in birefringence-managed fiber lasers

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中国光学快报:英文版 2023年第7期21卷 39-45页

作者：贺志文毛东杜岳卿高群曾超袁昌驰赵建林 Key Laboratory of Light Field Manipulation and Information Acquisition Ministry of Industry and Information TechnologyShaanxi Key Laboratory of Optical Information TechnologySchool of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an 710072China

We demonstrate spectral-furcated vector solitons in normal-dispersion fiber lasers comprising a section of polarizationmaintaining *** spectrum of each orthogonal-polarized component is confined by the birefringence-related phasematching principle,and the bicorn spectral structure corresponds to the zero-order sidebands of two vector *** to the Hopf bifurcation effect,the vector soliton evolves into a breathing state at the higher pump level,accompanied by an extra set of sub-sidebands that continuously exchange energy with the zero-order *** results fully reproduce experimental observations of the spectral furcation and soliton breathing,offering comprehensive insights into the pulse-shaping mechanism of the birefringence-managed soliton.

关键词： fiber laser soliton bicorn spectral structure birefringence management

Direct microwelding of dissimilar glass and Kovar alloy without optical contact using femtosecond laser pulses

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Journal of Central South University 2022年第10期29卷 3422-3435页

作者： JI Chang-hao HUANG Yu-jia CHEN Xu JIANG Ji-yan GUO Zhi-jun LONG Yu Institute of Laser Intelligent Manufacturing and Precision Processing School of Mechanical EngineeringGuangxi UniversityNanning 530004China Han’s Laser Technology industry Group Co. Ltd.Shenzhen 518057China

In the current microwelding process using femtosecond(fs) laser between dissimilar materials,surface polishing and pressure assistance,so-called optical contact,are believed *** this paper,direct welding of soda lime glass and Kovar alloy using a fs laser is investigated to overcome the limit of optical *** processing of fs laser welding is comprehensively studied by varying the laser power,welding velocity and the number of *** shear joining strength is as high as 2 *** cross-section of glass-Kovar alloy joints,the elemental diffusion and the fracture behavior of welded joints were *** results show that the fs laser irradiates the surface of Kovar alloy,micron/nanometer-sized metal particles are *** particles perform the role as an adhesive part in the welding *** is believed that the Si atoms diffuses to Kovar alloy from the glass and partially replaces the Fe^(2+) ions on the surface of Kovar alloy,indicating that the mixing and interdiffusion of materials have occurred during the welding ***,the welded sample was tested and has excellent water resistance and sealing ***,to justify that this method can be applied to other stack ups,the glass-copper,the glass-Al6063 and sapphire-ceramic are also welded *** work greatly simplifies the fs laser microwelding process and promotes its industrial applications,such as optoelectronic devices,medical devices and MEMS.

关键词： femtosecond laser microwelding glass Kovar alloy optical contact

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瓦螨微生物防治的不良效果(英文)

安徽农业大学学报 2007年第2期34卷 162-166页

作者：罗莎林.詹姆士 Hayes G USDA Agricultural Research Service Bee Biology & Systematics LaboratoryLoganUT Florida Department of Agriculture and Consumer Services Division of Plant industry Apiary section Gainesville Florida

We report six different field trials testing the efficacy of Metarhizium anisopliae,an entomopathogenic fungus,against varroa mites in honey bee *** mites are parasitic on honey bees and cause serious damage to Apis mellifera *** control methods are available for varroa mites,none are very effective,so new,more effective methods are being *** has previously been shown to be highly susceptible to *** infections,and in our first two field trials,we found some efficacy from spore ***,in subsequent field trials,we were not able to obtain any varroa control,despite attempting several different application methods,two different strains of the fungus,and testing in different climates and during different phenological states of the honey bee *** conclude that microbial control of varroa using fungi is not likely to be effective unless some way is found to prolong the survival of the spores(or other infective units)in the hive environment.

关键词：瓦螨微生物不良效果防治措施