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Numerical Simulation of Unsteady Discharge Flow with Fluctuation in Positive Discharge Blower

Chinese Journal of Mechanical Engineering 2009年第2期22卷 214-220页

作者： LIU Zhengxia wang dou XU Lianhuan School of Mechanical Engineering Tianjin University Tianjin 300072 China State Key Laboratory of Engines Tianjin University Tianjin 300072 China Xi＇an Shaangu Power Co. Ltd Xi＇an 710075 China Shandong Power Equipment Company Jinan 250022 China

The operating performance of positive discharge blower is markedly influenced by the pulsation of the discharge flow, but difficult to be measured with experimental methods. The internal and discharge flow of positive discharge blower with involute type three-lobe are numerically investigated, both in air cooling and countercurrent cooling conditions by means of computational fluid dynamics （CFD）. The unsteady compressible flow equations are solved using RNG x-ε turbulent model. The finite difference method and the second order upwind difference scheme are applied into discrete equations. In the numerical simulation, the dynamic mesh techniques are used to approach the rotating displacement of cell cubage and the alterability of inlet, outlet flow area. The non-uniform mesh is applied to the rotor-stator coupled area. The reliability of the numerical method is verified by simulating the inner flow and comparing with the semi-empirical theory. The flow flux curves and the distributing of velocity vector showed obvious vortex motion in all the discharge process, both in air cooling and countercurrent cooling conditions. These vortexes with different positions, intension and numbers at different rotating angles have remarkable influences on the discharge flux. For air cooling, the vortex produced a second pulsation with big-amplitude in a cycle, and led to the early appearance of maximum of backflow. For countercurrent cooling, the frequency of pulsation increased due to the pre-inflow, but the backflow at the outlet is prevented, also the pulsation strength has greatly decreased.

关键词： countercurrent cooling positive discharge blower dynamic mashing techniques flow fluctuation mumerical simulation

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ILC 3.2 km damping ring design based on the FODO cell

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Chinese Science Bulletin 2011年第16期56卷 1665-1670页

作者： wang dou GAO Jie XU Gang wang YiWei Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

We report on a new design for an ILC 3.2 km damping ring,with 2 arcs based on the FODO cell and 2 straight sections that are nearly the same as the newest version of the 6.4 km ring *** new lattice requires fewer magnets and a lower RF voltage, and has a better dynamic aperture than DCO4 while maintaining flexibility in regard to the momentum compaction *** far, this design is the only one satisfying all the requirements for a 3.2 km *** work on the lattice design and the dynamic aperture study is presented in detail.

关键词：阻尼环设计公里细胞基础最新版本压实系数直管段

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High birefringence, low loss, and flattened dispersion photonic crystal fiber for terahertz application

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Chinese Physics B 2019年第11期28卷 394-398页

作者： dou-dou wang Chang-Long Mu De-Peng Kong Chen-Yu Guo College of Sciences Xi’an University of Science and TechnologyXi’an 710054China The State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China

A type of photonic crystal fiber based on Kagome lattice cladding and slot air holes in a rectangular core is investigated. Full vector finite element method is used to evaluate the modal and propagation properties of the designed *** birefringence of 0.089 and low effective material loss of 0.055 cm^-1 are obtained at 1 THz. The y-polarized fundamental mode of the designed fiber shows a flattened and near-zero dispersion of 0±0.45 ps · THz^-1· cm^-1 within a broad frequency range(0.5 THz–1.5 THz). Our results provide the theory basis for applications of the designed fiber in terahertz polarization maintaining systems.

关键词： terahertz photonic crystal fiber birefringence loss dispersion

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Ion sulphuration-an effective surface engineering technique for reducing friction and wear of rubbing-pairs

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中国有色金属学会会刊：英文版 2004年第z1期14卷 13-18页

作者： LIU Jia-jun wang Hai-dou ZHANG Ning ZHANG Da-ming Department of Mechanical Engineering Tsinghua University Beijing 100084 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China Chinergy Co. Ltd. Beijing 100084 China Department of Mechanical Engineering Tsinghua University Beijing 100084 China

The low temperature ion sulphuration-an effective surface engineering technique for reducing friction and wear of rubbing-pairs was introduced. It involves the principle of ion sulphuration process, microstructure of FeS film on 1045 steel, tribological properties of FeS film on steels, microstructions and tribological properties of MoS2 and nano-FeS/MoS2 multi-layered films, as well as their applications.

关键词： solid lubrication low temperature ion sulphuration friction and wear surface engineering

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Antidepressant effect of Xingnao Jieyu decoction mediated by alleviating neuroinflammation in a rat model of post-stroke depression

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Journal of Traditional Chinese Medicine 2019年第5期39卷 658-666页

作者： Yan Yongmei Li Tao wang dou Zhao Bingbing Zhou Qi Department of Encephalopathy Affiliated hospital of Shaanxi University of Chinese Medicine

OBJECTIVE: To identify the antidepressant effect of Xingnao Jieyu (XNJY) decoction on a post-stroke depression (PSD) rat model and the underlying molecular mechanism. METHODS: We established a rat PSD model by middle cerebral artery occlusion (MCAO) combined with chronic unpredictable mild stress (CUMS). Healthy SD rats were randomly divided into six groups: sham, PSD, fluoxetine (Flu), and XNJY groups at low, middle, and high doses. The sham group underwent sham operation, while the other groups underwent MCAO+CUMS. The Flu and XNJY decoction groups were intragastrically administered with Flu or different doses of XNJY for 21 consecutive days. Histopathological changes in the cortex and hippocampus were observed by staining with hematoxylin and eosin and Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling. Iba1 positive cells were evaluated by immunofluorescence assay. The expressions of tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6), interleukin-1β(IL-1β), 5-hydroxytryptamine (5-HT), and norepinephrine (NE) in the cortex and hippocampus were measured by enzyme linked immunosorbent assay. RESULTS: The PSD group rats had a significant decrease in body weight, consumption of sucrose water, and locomotor activity but an increase in immobility time during a forced swimming test (P < 0.01) compared with sham group. Flu and different doses of XNJY significantly recovered these indices (P < 0.01). XNJY also inhibited neuronal damage and apoptosis in the cortex induced by PSD (P < 0.01). Furthermore, XNJY reduced the number of Iba1 positive cells and the expressions of TNF-α, IL-6, and IL-1β, in addition to recovered the levels of 5-HT and NE in the cortex and hippocampus (P < 0.01). CONCLUSION: The alleviation of neuroinflammation might be an important mechanism of the XNJY decoction against PSD. Thus, XNJY might be a promising candidate for the treatment of PSD.

关键词： Depression Stroke Infarction, middle cerebral artery Stress Inflammation Antidepressive agents Xingnao Jieyu

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Failure behavior of protective organic coatings under corrosive conditions

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中国有色金属学会会刊：英文版 2004年第z1期14卷 395-404页

作者： ZHANG Xian-cheng XU Bin-shi wang Hai-dou WU Yi-xiong National Key Laboratory of Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory of Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory of Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China School of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200030 China

Recent research activities on the formation of micro-defects and porosity in organic coatings were reviewed. The mechanisms of aggressive ionic conduction through organic coatings were analyzed. The micro-mechanisms for the failure behavior of coatings under corrosive environments were discussed in detail. These mechanisms included blistering (i. e. osmotic blistering, anodic blistering and cathodic blistering) in the coating, wet-adhesion loss at the substrate/coating interface, cathodic delamination of coating from the substrate. Based on these researches, it was found that the failure behavior of organic coatings is closely related to the micro-defects in coatings, regardless of the failure mode. Additionally, the general failure mode of a coating system was proposed to interpret the failure behavior of organic in corrosion environments. The topics discussed can provide some insights into the development of a methodology for designing fail-safe coating systems.

关键词： organic coating micro-defect porosity failure mechanism failure mode

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Wear-resistance and anti-scuffing of multi-arc ion plating molybdenum films

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中国有色金属学会会刊：英文版 2004年第z1期14卷 391-394页

作者： wang Hai-dou XU Bin-shi LIU Jia-jun ZHUANG Da-ming National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China Department of Mechanical Engineering Tsinghua University Beijing 100084 China Department of Mechanical Engineering Tsinghua University Beijing 100084 China

The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.

关键词： multi-arc ion plating molybdenum film wear and scuffing

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Post-earthquake building damage assessment in Yushu using airborne SAR imagery

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Earthquake Science 2011年第5期24卷 463-473页

作者： Dingjian Jin Xiaoqing wang Aixia dou Yanfang Dong Institute of Earthquake Science China Earthquake Administration Beijing 100036 China

The synthetic aperture radar （SAR） plays an important role in earthquake emergency response because of its all-time and all-weather imaging capabilities. On April 14, 2010, an Ms7.1 earthquake occurred in Yushu county, Qinghai province of China, causing a lot of buildings collapsed. In this paper, the building damage in Yushu city due to the earthquake was assessed quantitatively using high-resolution X-band airborne SAR image. The features of the buildings with different damage levels （collapsed, partial collapsed, non-collapsed） in the SAR image were analyzed first. Based on these building features, we interpreted the individual building damage in Yushu city block by block and got the numbers of the collapsed, partial collapsed and non-collapsed buildings separately for each block, referring to pre-earthquake QuickBird image when necessary. Let the damage index of individual collapsed, partial collapsed, non-collapsed building be 1, 0.5, 0 respectively, the remote sensing damage index of each block was then calculated through remote sensing damage index equation. Finally, the preliminary quantitative relationship between the remote sensing damage index interpreted from the SAR image and that interpreted from the optical image was built up. It can be concluded that a desirable damage assessment result can be derived from high-resolution airborne SAR imagery.

关键词： SAR remote sensing Yushu earthquake damage assessment seismic damage index manual interpretation

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Design,Manufacture and Maintenance of Pressure Equipment Based on Accidents Survey

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 167-178页

作者： CHEN Xuedong AI Zhibin FAN Zhichao wang Bing dou Wanbo YANG Tiecheng GUAN Weihe National Technical Research Center on Safety Engineering of Pressure Vessels and Pipelines Hefei General Machinery Research Institute Hefei 230031 China

Most of the important units of pressure equipment have been manufactured successfully in China related to the national key construction projects,such as 10 million tons/year oil refinery,million tons/year ethylene,large coal chemical,***,some of them failed to operate shortly after their putting into *** suffered severe damage even during the previous period of manufacture and *** this paper,cases of accident survey and failure analysis are given for some typical pressure *** is found that many accidents are related to insufficient consideration of the design and manufacture of the *** accidents occur fundamentally because of the Chinese design standards codes for pressure equipment without risk or life concepts and the support from a database for potential risk existing in their dynamic *** designers and manufacturers are unable to make correct design,materials selection and manufacturing process all due to a lack of engineering *** order to avoid the repetition of the accidents and improve the safety,reliability and economy of pressure equipment,a platform is suggested for design,manufacture and maintenance of pressure equipment in China based on accidents *** other words,some effective precautionary measures are taken at the design and manufacture stage,and the design methodology has to be based on service life requirement and desirable risk *** the service stage some reasonable inspection/monitoring approaches should be utilized to control risks and ensure the equipment operating safely until its desired ***,the basic scheme and some key technologies are briefly given for the platform *** concept of risk and life based design,manufacture and maintenance proposed herein has important significance for improving and perfecting the codes and standards for design,manufacture and maintenance of Chinese pressure-bearing equipment,enhancing the life and reliability of

关键词： pressure vessel pressure piping damage risk design manufacture maintenance

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Influence of heat treatment on microstructures and micro-hardness of n-SiO2/Ni composite coating

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中国有色金属学会会刊:英文版 2004年第z1期14卷 111-114页

作者： XU Bin-shi wang Hai-dou DONG Shi-yun JIANG Bin TU Wei-yi National Key Laboratory for remanufacturing Academy of Armored Force Engineering Beijing 100072 China

The n-SiO2/Ni composite electro-brush plating coating was prepared on the 1045 steel substrate. SEM and TEM were utilized to analyze the surface and cross-section morphologies or the microstructures of the composite coating before and after heat treatment, as well as a micro-hardness tester was used to measure the micro-hardness before and after heat treatment. The results show that the entrance of nano SiO2 particles into composite coating makes the micro-hardness higher. After heat treatment, due to the obstruction to growth of Ni crystals from nano particles, the composite coating still possesses a higher micro-hardness than that of common Ni-base coating.

关键词： nano SiO2 particles electro-brush plating composite coating heat treatment microstructures microhardness

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