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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

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

Enhancing the resolution of seismic data based on the generalized S-transform

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Petroleum Science 2009年第2期6卷 153-157页

作者： Tian jianhua Song wei Yang Feizhou State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China Key Laboratory of CNPC Geophysical Prospecting China University of Petroleum Beijing 102249 China

In this paper, we analyze the seismic signal in the time-frequency domain using the generalized S-transform combined with spectrum modeling. Without assuming that the reflection coefficients are random white noise as in the conventional resolution-enhanced techniques, the wavelet which changes with time and frequency was simulated and eliminated. After using the inverse S-transform for the processed instantaneous spectrum, the signal in the time domain was obtained again with a more balanced spectrum and broader frequency band. The quality of seismic data was improved without additional noise.

关键词： Time-frequency domain generalized S-transform spectrum modeling instantaneous spectrum balanced spectrum

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.

Dosimetric parameters of palladium-103 brachytherapy source with Monte Carlo simulation

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Chinese Science Bulletin 2008年第9期53卷 1304-1309页

作者： WANG jianhua LIU wei XU XunJiang GU JiaHui CAI Jun HUA ZhengDong XU JiaQiang Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China

Before clinical application of a new source, the dosimetric parameters of the source should be accu- rately determined. This work is dedicated to the Monte Carlo method to calculate dosimetric parameters as recommended by the American Association of Physicists in Medicine (AAPM) TG-43 guidelines for model ADVANTAGETM palladium-103 source and, through comparison with data from another published report for the same source, presents a suggested dataset for clinical applications. From these calcula- tions, tables are presented for the radial dose function and the anisotropy function of palladium-103 brachytherapy source. The dose rate constants are found to be 0.671 (cGyh-1U-1) in liquid water and 0.673 (cGyh-1U-1) in Solid WaterTM. And the anisotropy constants in liquid water and Solid WaterTM are found to be 0.864 and 0.865 respectively. Comparison with the previous study shows that our results of dosimetric parameters are in good agreement with those measured and calculated by Meigooni et al. (2006) both in Water and Solid WaterTM.

关键词：短程治疗钯-103 测量参数数学模型