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An improved CFD model of gas flow and particle interception in a fiber material

Chinese Journal of Chemical Engineering 2017年第3期25卷 264-273页

作者： Zhiwei Sun Jianhui wen Xiao Luo wen du Zhiwu Liang Kaiyun Fu Technology Center of China Tobacco Hunan Industrial Co. Ltd. Joint International Center for CO2 Capture and Storage (iCCS) Hunan Provincial Key Laboratory for Cost-effective Utilization of Fossil Fuel Aimed at Reducing CO2 EmissionsCollege of Chemistry and Chemical EngineeringHunan University

An improved CFD model of gas flow and particle interception in a fiber material which fiber size is Y-shape was developed in this work. The porous medium model was used to build the model of the whole size of fiber filter medium. Mixture model was adopted. The algorithm of particle interception in the whole size of fiber filter medium was derived and UDF(User Defined Function) that described kinds of particle filtering mechanisms in filter fibrous media was added to the Fluent default conservation equation as source term for simulation. The inertial resistance of the filter was taken into consideration, which provided a more precise measurement of the smoke flow and the particle interception in the filter under higher smoke speed conditions. The commercial software, Fluent 6.3, was used to simulate the smoke flow and particle interception in the filter in a single suction. The velocity and pressure profiles of smoke or nicotine particle in the filter, as well as nicotine particle volume fraction profile were well simulated. Finally, the comparisons of nicotine particle filtration efficiency between Fluent simulation results in this work and experimental results, as well as the model prediction in the literature were made to validate the simulation model. The comparisons showed that the particle entrapment model from simulation results was in good agreement with that from the experimental results. In addition, the Fluent simulation results are closer to reality both at the beginning and the end of the smoke process comparing with the model predicted results in the literature.

关键词： Numerical simulation Y-shape fiber Particle interception Flow field distribution Filtration efficiency UDF

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Precipitation behavior of 14H-LPSO structure in Mg–12Gd–2Er–1Zn–0.6Zr Alloy

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Rare Metals 2016年第5期35卷 367-373页

作者： Kai wen wen-Bo du Ke Liu Zhao-Hui Wang Shu-Bo Li College of Materials Science and Engineering Beijing University of Technology

The microstructures of as-cast and as-solution Mg–12Gd–2Er–1Zn–0.6Zr alloys were investigated by optical microscopy（OM）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, highresolution transmission electron microscopy（HRTEM）X-ray diffraction（XRD） and selected-area electron diffraction（SAED） in the present investigation. The results show that the primary eutectic phase Mg5（Gd, Er, Zn） and some flocculent features are found in the as-cast alloy; the SAED pattern indicates that these flocculent features are the dense areas of stacking faults. The 14H-LPSO structure precipitates in the temperature range of 673–793 K, and the volume fraction of 14H-LPSO structure increases with the extension of heating time; however, there is no precipitation of 14H-LPSO structure when the temperature reaches up to 803 K. In addition, the Mg5（Gd, Er, Zn） phase dissolves gradually along with the precipitation of 14H-LPSO structure.

关键词： Mg–Gd–Er–Zn–Zr alloy Dense stacking faults area Heat treatment Microstructure

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Microstructures and mechanical properties of homogenization and isothermal aging Mg–Gd–Er–Zn–Zr alloy

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Rare Metals 2016年第6期35卷 443-449页

作者： Kai wen wen-Bo du Ke Liu Zhao-Hui Wang Shu-Bo Li College of Materials Science and Engineering Beijing University of Technology

The effects of homogenization and isothermal aging treatment on the mechanical properties of Mg-12Gd- 2Er-1Zn-0.6Zr （wt%） alloy were investigated. The precipitated long-period stacking order （LPSO） structure and the aging precipitation sequence of the conditioned alloys were observed and analyzed, respectively. The results indicate that the 14H-LPSO structure occurs after the homogenization treatment and the 131 phase forms after the isothermal aging process. These two independent processes could be controlled by the precipitation temperature range. The significant increase in the elongation of the as-cast alloy after homogenization treatment is attributed to the disappearance of the coarse primary Mgs（Gd, Er, Zn） phase and the presence of the 14H-LPSO structure. The precipitation sequence of the investigated alloy is α-Mg（SSS）/β″（D019）/β′（cbco）/β. Furthermore, the yield tensile strength （YTS） and ultimate tensile strength （UTS） values of the isothermal aging alloy have a great improvement, which could be attributed to the high density of the precipitated β′ phase.

关键词： Magnesium alloys Isothermal aging Mechanical properties Mg-Gd-Er-Zn(Zr) Microstructures

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Research of 6-DOF Serial-Parallel Mechanism Platform for Stability Training of Legged-Walking Robot

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Journal of Harbin Institute of Technology(New Series) 2014年第2期21卷 75-82页

作者： Wei-Guo Wu wen-Qian du Humanoid and Gorilla Robot & Its Intelligent Motion Control Lab Harbin Institute of Technology

The concept of legged-robot stability training with a training platform is proposed and a serial-parallel mechanism platform with 6 degrees of freedom is designed for this target. The designed platform is composed of 4-DOF parallel mechanism with spherical joints and prismatic pairs,and 2-DOF serial mechanism with prismatic pairs. With this design,the platform has advantages of low platform countertop,big workspace,high carrying capacity and high stiffness. On the basis of DOF analysis and computation of space mechanism,weight supporting auxiliary mechanism and raceways-balls supporting mechanism are designed,so as to improve the stiffness of designed large platform and payload capacity of servo motors. And then the whole structure design work of the platform is done. Meanwhile,this paper derives the analytical solutions of forward kinematics, inverse kinematics and inverse dynamics. The error analysis model of position and orientation is established. And then the simulation is done in ADAMS to ensure the correctness and feasibility of this design.

关键词： 6-DOF serial-parallel mechanism forward kinematics stability training legged-walking robot

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SPATIAL DIFFERENTIATION OF LAND TRANSFER——Case Study of Shanghai, Nanjing and Taizhou in Changjiang River Delta

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Chinese Geographical Science 2006年第1期16卷 24-31页

作者： du wen-xing HUANG Xian-jin ZHAI wen-xia PENG Bu-zhuo Department of Urban and Resources Sciences Nanjing University Nanjing 210093 P. R. China Department of Urban Plnnning and Resources Sciences Xianning College Xianning 437005 P. R. China

The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households＇ behavior. This paper selected I l factors covering four aspects of rural households＇ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households＇ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang （Yangtze） River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households＇ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.

关键词： land transfer spatial differentiation land transaction Changjiang River Delta

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New phenomena in laser-assisted scattering of an electron by a muon

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Frontiers of physics 2018年第4期13卷 251-258页

作者： wen-Yuan du Peng-Fei Zhang Bing-Hong Wang Department of Modern Physics University of Science and Technology of China Hefei 230026 China

The scattering of an electron by a muon in the presence of a linearly polarized laser field is investigated in the first Born approximation. The theoretical results reveal the following： i） At medium and large scattering angles, many multiphoton processes occur during scattering, and these nonlinear phenomena may predict the resonant state of the electron and the muon formed in the collision process, ii） The photoabsorption （inverse brerasstrahlung） dominates the photoemission （bremsstrahlung）, causing the cross section to increase, iii） When the laser polarization deviates from the incident direction, the laser- modified total cross section depends considerably on the azimuthal angle of the scattered electron. The dependence of the cross section on the field strength, polarization direction, and electron-impact energy are studied.

关键词： laser-assisted scattering multiphoton processes nonlinear effect generalized Bessel function

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A new model for wrinkling and collapse analysis of membrane inflated beam

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Acta Mechanica Sinica 2010年第4期26卷 617-623页

作者： Chang-Guo Wang Hui-Feng Tan Xing-wen du Xiao-Dong He Center for Composite Materials Harbin Institute of TechnologyHarbin 150001 China Postdoctoral Research Center in Material Science and Engineering Harbin Institute of Technology Harbin 150001 China

A new model is proposed to accurately predict the wrinkling and collapse loads of a membrane inflated beam. In this model, the pressure effects are considered and a modified factor is introduced to obtain an accurate prediction. The former is achieved by modifying the pressure-related structural parameters based on elastic small strain considerations, and the modified factor is determined by our test data. Compared with previous models and our test data, the present model, named as shell-membrane model, can accurately predict the wrinkling and collapse loads of membrane inflated beams.

关键词： Inflated beam. Shell-membrane. Bending Wrinkling Collapse

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In vitro inhibition of proliferation,migration and epithelial-mesenchymal transition of human lens epithelial cells by fasudil

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International Journal of Ophthalmology(English edition) 2018年第8期11卷 1253-1257页

作者： Jing-Zhi Shao Ying Qi Shan-Shan du wen-wen du Fu-Zhen Li Feng-Yan Zhang Department of Ophthalmology the First Affiliated Hospital of Zhengzhou University

AIM： To study the potential role of fasudil as a treatment for posterior capsular opacification（PCO） of the human crystalline ***： Human lens epithelial cells（HLECs; line SRA01/04） was exposed to transforming growth factor-β2（TGF-β2） to induce the process of epithelial-mesenchymal transition（EMT）. Fasudil was applied to the cell samples. Its effect on overall HLECs proliferation and migration was studied, as was its influence on EMT induction by TGF-β2 using cell migration assay, MTT colorimetric assay and Western blot ***： Fasudil inhibited the proliferation of SRA01/04. Its effect was time-and concentration-dependent. The migration of SRA01/04 cells was significantly reduced 24-72 h after fasudil treatment, and the half maximal inhibitory concentration（IC50） was 22.37 μmol/mL at 72 h. Reversal of the elongated, fibroblast-like shape changes induced by TGF-β2 in SRA01/04 cells was observed. Fasudil up-regulated the expression of Connexin43 protein and down-regulated the expression of α-SMA protein compared with the cells treated with TGF-β2. Furthermore, when exposed to fasudil, the phosphorylation of Rhoassociated protein kinase（Rock） and myosin light chain（MLC） could not be activated in the cell ***： Fasudil suppresses the proliferation and migration of SRA01/04 cells, and inhibits the process of EMT induced by TGF-β2. These results suggest that fasudil may serve as a therapeutic agent for PCO.

关键词： fasudil human lens epithelial cells TGF-β2 Rho/Rock epithelial-mesenchymal transition

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Glutamine supplementation attenuates intestinal apoptosis by inducing heat shock protein 70 in heatstroke rats

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World Journal of Emergency Medicine 2023年第1期14卷 37-43页

作者： Li-wen du Bao-qing Xu Kai Xun Fang-qi Zhang Department of Emergency Ningbo No.2 HospitalNingbo 315000China Department of Pathology the 900th Hospital of Joint Logistics Support Force of Chinese PLAFuzhou 350025China Department of Pulmonary and Critical Care Medicine the 987th Hospital of Joint Logistics Support Force of Chinese PLABaoji 721000China

BACKGROUND:Heatstroke is the most hazardous heat-related illness and has a high fatality *** investigated whether glutamine supplementation could have a protective effect on heatstroke ***:Twenty-five 12-week-old male Wistar rats(weight 305±16 g)were randomly divided into a control group(n=5),heatstroke(HS)group(n=10),and heatstroke+glutamine(HSG)group(n=10).Seven days before heat exposure,glutamine(0.4 g/[kg·d])was administered to the rats in the HSG group by gavage every *** hours after heat exposure,serum samples were collected to detect white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines in the *** small intestine tissue was stained to analyze pathological structural changes and ***,immunohistochemistry and Western blotting were used to analyze the expression levels of heat shock protein 70(HSP70).Multiple comparisons were analyzed by using one-way analysis of variance,and the Bonferroni test was conducted for the post hoc ***:After heat exposure,the core temperature of the HS group(40.65±0.31°C)was higher than the criterion of heatstroke,whereas the core temperature of the HSG group(39.45±0.14°C)was lower than the *** supplementation restored the increased white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines that were induced by heatstroke to normal *** intestinal mucosa was injured,and the structure of tight junctions was damaged in the HS group;however,the structure of intestinal mucosal epithelial cells was stable in the HSG *** supplementation alleviated intestinal apoptosis and up-regulated HSP70 ***:Glutamine supplementation may alleviate intestinal apoptosis by inducing the expression of HSP70 and have a protective effect on heatstroke rats.

关键词： Heatstroke Glutamine Core temperature Intestinal apoptosis Heat shock protein 70

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Correlation between age of onset and gastrointestinal stenosis in hospitalized patients with Crohn's disease

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World Journal of Clinical Cases 2020年第13期8卷 2769-2777页

作者： Shan-Bing Yang Shu-wen du Ji-Heng Wang Department of Gastroenterology the Seventh Medical CenterChinese People’s Liberation Army General HospitalBeijing 100700China

BACKGROUND Patients affected by Crohn's disease(CD)are more likely to develop gastrointestinal stenosis and often undergo surgery during the duration of *** To identify the risk factors for gastrointestinal stenosis in hospitalized CD patients in *** The clinical data of CD patients hospitalized at the Seventh Medical Center,Chinese People's Liberation Army General Hospital from January 2010 to December 2018 were *** with gastrointestinal stenosis were compared to those without gastrointestinal stenosis for clinical *** risk factors for gastrointestinal stenosis were identified using univariate and multivariable logistic regression *** treatments for patients with gastrointestinal stenosis were analyzed,and the characteristics of different treatment methods were *** The incidence of gastrointestinal stenosis was 59.02%in the 122 hospitalized CD *** of onset of more than 40 years(odds ratio[OR]=3.072,95%confidence interval[CI]:1.298-7.272,P=0.009)and duration of disease of more than 5 years(OR=2.101,95%CI:1.002-4.406,P=0.048)were associated with the occurrence of gastrointestinal ***(20.83%)patients did not undergo surgery and received internal medicine and nutrition *** treatments were performed in 72.22%(52)of *** rate of postoperative complications was 15.38%(8 cases),and during a median follow-up period of 46 mo,11.54%(6 cases)underwent reoperation.A total of 29.17%(21 cases)were treated with endoscopic therapy,and during a median follow-up period of 32 mo,76.19%(16 cases)had no surgical event,23.81%(5 cases)failed to avoid surgical treatments,and no serious postoperative complications occurred after endoscopic *** Age of onset of more than 40 years and duration of disease of more than 5 years may be strongly correlated with a higher risk of gastrointestinal stenosis in hospitalized CD *** therapy for gastrointestinal stenosis

关键词： Crohn's disease Gastrointestinal stenosis Age of onset duration of disease Endoscopy Surgery

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