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Laminar Flow in the Gap between Two Rotating Parallel Frictional Plates in Hydro-viscous Drive

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Chinese Journal of Mechanical Engineering 2012年第1期25卷 144-152页

作者： HUANG Jiahai wei jianhua QIU Minxiu The State Key Lab of Fluid Power Transmission and Control Zhejiang UniversityHangzhou 310027China

The velocity, pressure and temperature distributions of the flow in the gap between hydro-viscous drive friction disks are the key parameters in the design of hydro-viscous drive and angular velocity controller. In the previous works dealing with the flow in the gap between disks in hydro-viscous drive, few authors considered the effect of Coriolis force on the flow. The object of this work is to investigate the flow with consideration of the effects of centrifugal force, Coriolis force and variable viscosity. A simplified mathematical model based on steady and laminar flow is presented. An approximate solution to the simplified mathematical model is obtained by using the iteration method assuming that the fluid viscosity remains constant. Then the model considering the effect of variable viscosity is solved by means of computational fluid dynamics code FLUENT. Numerical results of the flow are obtained. It is found that radial velocity profile diverges from the ideal parabolic curve due to inertial forces and tangential velocity profile is nonlinear due to Coriolis force, and pressure has two possible solution branches. In addition, it is found that variable viscosity plays an important role on pressure profiles which are significantly different from those of fluid with constant viscosity. The experimental device designed for this work consists of two disks, and one of them is fixed. Experimental pressure and temperature of the flow within test rig are obtained. It is shown that the trend of numerical results is in agreement with that of experimental ones. The research provides a theoretical foundation for hydro-viscous drive design.

关键词： hydro-viscous drive rotating disks flow inertial force viscosity-temperature characteristics

A novel Pd/silicalite-1 composite membrane for hydrogen separation

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Chinese Science Bulletin 2009年第12期54卷 2131-2133页

作者： XlAO wei YANG jianhua WANG JinQu State Key Laboratory of Fine Chemicals of Dalian University of Technology Dalian 116012 China

A novel Pd/silicalite-1 composite membrane supported on the macroporous tubular stainless steel substrate was successfully fabricated by electroless plating at 303 K. The structure, morphology and gaseous permeability of the membrane were detected by X-ray diffractiometry (XRD), scanning electron microscopy (SEM) and single-gas permeation test, respectively. Results confirm the formation of a thin, smooth, and continuous Pd/silicalite-1 composite membrane. The obtained composite membrane shows a high H2 permeance of 1.15×10-6 mol·m-2·s-1·Pa-1 with moderate H2 selectivity of 250 for H2/N2 at 773 K, at 0.1 MPa pressure drop, suggesting the potential application for H2 separation.

关键词：复合膜氢气分离化学镀光气体渗透膜

THEORY AND APPLICATION OF πBRIDGE HYDRAULIC RESISTANCE NETWORKS

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中国有色金属学会会刊：英文版 1999年第1期9卷 204-208页

作者： Yanping, Hu jianhua, wei Yingfu, Guo Genmao, Wu Deshun, Liu Xiangtan Polytechnic Univ Xiangtan China

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｔｗｏｋｉｎｄｓｏｆｈｙｄｒａｕｌｉｃｎｅｔｗｏｒｋｓ，ｉ．ｅ．４ａｒｍｓｂｒｉｄｇｅｈｙｄｒａｕｌｉｃｒｅｓｉｓｔａｎｃｅｎｅｔｗｏｒｋａｎｄｈａｌｆｂｒｉｄｇｅｈｙｄｒ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｔｗｏｋｉｎｄｓｏｆｈｙｄｒａｕｌｉｃｎｅｔｗｏｒｋｓ，ｉ．ｅ．４ａｒｍｓｂｒｉｄｇｅｈｙｄｒａｕｌｉｃｒｅｓｉｓｔａｎｃｅｎｅｔｗｏｒｋａｎｄｈａｌｆｂｒｉｄｇｅｈｙｄｒａｕｌｉｃｒｅｓｉｓｔａｎｃｅｎｅ...

关键词： hydraulic resistance network theory application

Kondo resonance assisted thermoelectric transport through strongly correlated quantum dots

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Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 118-126页

作者： YongXi Cheng ZhenHua Li jianhua wei HongGang Luo HaiQing Lin YiJing Yan Beijing Computational Science Research Center Beijing 100193China Department of Science Taiyuan Institute of TechnologyTaiyuan 030008China School of Physical Science and Technology Key Laboratory for Magnetism and Magnetic Materials of the MoELanzhou UniversityLanzhou 730000China Department of Physics Renmin University of ChinaBeijing 100872China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

We theoretically studied the thermoelectric transport properties of a strongly correlated quantum dot system in the presence of the Kondo effect based on accurate numerical evaluations using the hierarchical equations of motion *** thermocurrent versus gate voltage shows a distinct sawtooth line-shape at high *** particular,the current changes from positive(hole charge)to negative(particle charge)in the electron number N=1 region due to the Coulomb blockade ***,at low temperatures,where the Kondo effect occurs,the thermocurrent’s charge polarity reverses,along with a significantly enhanced *** anticipated,the current sign can be analyzed by the occupation difference between particle and ***,the characteristic turnover temperature can be further defined at which the influences of the Coulomb blockade and Kondo resonance are in an effective ***,the identified characteristic turnover temperature,as a function of the Coulomb interaction and dot-lead coupling,possessed a much higher value than the Kondo *** a magnetic field is applied,a spin-polarized thermocurrent can be obtained,which could be tested in future experiments.

关键词： thermoelectric transport strongly correlated quantum dot Kondo resonance spin-polarized thermocurrent

Dynamic Per-flow Queuing to Reduce Competitions Among Large Number of Flows

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Chinese Journal of Electronics 2014年第4期23卷 783-789页

作者： wei jianhua ZHU Lei ZHANG weichuan FENG Zhi GUO Peng Electronics and Information College Xi'an Polytechnic University

Per-flow queuing is believed to be able to guarantee advanced Quality of service(Qo S) for each flow at high speed routers. With the dramatic increase for both link speed and number of traffic flows, per-flow queuing confronts a great challenge, since millions of queues need to be maintained for implementation in a traditional sense. In this paper, setting only a small number of physical queues,we propose a Dynamic per-flow queuing(DPFQ) mechanism that achievesthe same performance as per-flow queuing at a cost of an additional Binary content addressable memory(BCAM). The proposed mechanism works due to the fact that the number of simultaneous active flows at a mini-time scale in the router buffer is much smaller than that of in-progress flows. In DPFQ, a physical queue is created on demand when a new flow comes, and released when the flow temporarily pauses or finishes. A small BCAM is occupied to map flows to queues, so as to guarantee that only the packets from the same flow are buffered in any assigned queue. Through analysis and simulation we show that using a small number of physical queues,DPFQ achieves both low operation delay and power consumption.

关键词： Packet buffers Memory management Per-flow queuing

Virus-induced silencing of a tobacco deoxyhypusine synthase gene

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Chinese Science Bulletin 2005年第23期50卷 2707-2713页

作者： WANG Hongzhi MA Rongcai LI Ruifen WANG Guoying wei jianhua State Key Laboratory for Agrobiotechnology China Agricultural University Beijng 100094 China Beijing Agro-Biotechnology Research Center Beijing Academy of Agriculture and Forestry Science Beijing 100089 China

A cDNA fragment corresponding to deoxyhy-pusine synthase gene NbDHS was isolated and cloned into potato virus X (PVX) vector for functional analysis in Nico-tiana benthamiana by using virus-induced gene silencing (VIGS). Plants agroinfected with recombinant virus vector PVX-NbDHS exhibited an increase in leaf biomass, delay in natural leaf senescence and flowering time, and decrease in leaf chlorophyll content. Semi-quantitative RT-PCR and Northern analysis showed that the transcript level of DHS was significantly lower in PVX-NbDHS infected plants. At the same time, the expression for eIF-5A, the target proteins of DHS in N. benthamiana, was concomitantly suppressed by semi-quantitative RT-PCR and Western analysis. From the phenotypic feature of the infected plants and the reduced expression abundance of DHS and eIF-5A, we concluded that NbDHS plays important roles in plant growth, development and senescence. The possible application of DHS gene in ge-netic modification of crops and horticultural plants was dis-cussed.

关键词：烟草脱氧羟腐胺缩赖氨酸合酶基因基因克隆生长促进作用

Clinical Characteristics of Human Adenovirus Plastic Bronchitis in 10 Pediatric Cases: A Retrospective Study of Seven Years

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Virologica Sinica 2021年第3期36卷 550-554页

作者： Lingjian Zeng jianhua wei Yuyi Tang Enmei Liu Qubei Li Na Zang Department of Respiratory Medicine Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisorderChildren’s Hospital of Chongqing Medical UniversityChongqing Key Laboratory of PediatricsChongqing 400014China

Dear Editors,In recent years,human adenovirus (HAd V) infection has been prevalent in various regions in China (Duan et al.2021).Research in Guangzhou reported that 9.14%of fatal pneumonia cases showed HAd V-PCR posit... 详细信息

关键词： mortality Clinical

Lignin biosynthesis by suppression of two O-methyl-transferases

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Chinese Science Bulletin 2002年第13期47卷 1092-1095,1145页

作者： ZHAO Huayan wei jianhua ZHANG Jinyu LIU Huirong WANG Tai SONG Yanru Institute of Botany Chinese Academy of SciencesBeijing 100093China Beijing Center of Agro-Biotechnology Beijing Institute of Agriculture and ForestryBeijing 100089China 不详

Caffeic acid O-methyltransferase (COMT) and caffeoyl-CoA-3-O-methyltransferase (CCoAOMT) genes encode two methyltransferases at different substrate levels in lignin biosynthesis. We constructed two single antisense expression vectors containing the cDNA of COMT or CCoAOMT genes and one dual antisense expression vector containing cDNAs of both OMTs genes. The antisense constructs were transferred into tobacco mediated by Agrobac-terium tumefacience. PCR-Southern analysis indicated that antisense cDNAs had been integrated into the genome of the transgenic tobacco. The antisense genes were also expressed at transcriptional level displayed by Northern dot analysis. Klason lignin assay of 3-month-old transgenic tobaccos showed that repression in COMT or CCoAOMT alone could result in reduction of lignin content, more reduction was caused by suppression in CCoAOMT than in COMT. Furthermore, simultaneous suppression of both COMT and CCoAOMT resulted in more reduction than that of single gene, which indicated

关键词： COMT CCoAOMT antisense RNA lignin histochemi-cal staining.

Mechanochemical decomposition of pentachlorophenol by ball milling

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Journal of Environmental Sciences 2009年第12期21卷 1761-1768页

作者： wei Yinglei, YAN jianhua, LU Shengyong, LI XiaodongState Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. [a] State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The mechanochemical dechlorination of pentachlorophenol （PCP） was studied using CaO and SiO2 powder as additives. The effects of the milling time and additives on the dechlorination rate were investigated. The resulting product was characterized by X-ray diffraction （XRD）, Fourier transform infrared spectra （FT-IR）, thermogravimetric analysis （TG） and ion chromatography （IC）. It is found that grinding operation could dechlorinate PCP, with the formation of inorganic chloride and amorphous carbon. The addition of quartz to the grinding mixture facilitated dechlorination. On the basis of the experimental results, the decomposition mechanism was proposed. Decomposition predominantly proceeds through rupture of C-Cl bond in PCP molecule, followed by the formation of inorganic chlorides.

关键词： ball milling dechlorination mechanochemical pentachlorophenol