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38篇 您的检索式:作者名="Weixing Yu"
    题名 作者 年代 出处 被引量
1A Phytophthora capsici RXLR Effector Targets and Inhibits a Plant,PPlase to Suppress Endoplasmic Reticulum-Mediated Immunity显示文摘Guangjin Fan Yang Yang Tingting Li Wenqin Lu Yu DU Xiaoyu Qiang Qujiang Wen Weixing Shan 2018Molecular Plant2018,11,8:18
2High-sum-rate beamformers for multi-pair two-way relay networks with amplify-and-forward relaying strategy显示文摘In multi-pair two-way relay networks,the control over inter-pair-interference is a challenging problem.When mobile stations(MSs)cooperate fully,to achieve the sum capacity of networks and at the same time completely remove the inter-pair-interference,a singular value decomposition(SVD)based beamforming scheme at relay station(RS)is established where SVD beamformers are applied over both uplink and downlink channels,respectively.To avoid any cooperation among users,an efcient beamforming scheme is proposed.This scheme uses the Max-SINR based receive beamformer at RS in uplink channel and the Max-SLNR based transmit precoder at RS in downlink channel.It omits interference(uplink)and leakage(donwlink)inside each pair of users due to their abilities of self-interference cancellation.This beamforming scheme provides an analytical solution like some well-known linear beamformers such as zero-forcing,block diagonalization,etc.From simulation,we find:the proposed SVD shows an excellent sum-rate performance at the expense of a large cooperation overhead at MSs and can be used as a tighter upper bound of sum-rate;the proposed scheme of Max-SINR beamformer plus Max-SLNR precoder performs much better on sum-rate than the ZF-based and the BD-based schemes by using almost the same computational amount.SHU Feng LU YaZhe CHEN Yu YOU XiaoHu WANG JianXin WANG Mao SHENG WeiXing CHEN Qian 2014Science China(Information Sciences)2014,57,2:15
3Modeling gross primary production of a temperate grassland ecosystem in Inner Mongolia, China, using MODIS imagery and climate data显示文摘Carbon fluxes in temperate grassland ecosystems are characterized by large inter-annual variations due to fluctuations in precipitation and land water availability. Since an eddy flux tower has been in operation in the Xilin Gol grassland, which belongs to typical temperate grassland in North China, in this study, observed eddy covariance flux data were used to critically evaluate the biophysical per- formance of different remote sensing vegetation indices in relation to carbon fluxes. Furthermore, vegetation photosynthesis model (VPM) was introduced to estimate gross primary production (GPP) of the grassland ecosystem for assessing its dependability. As defined by the input variables of VPM, Moderate Resolution Imaging Spectroradimeter (MODIS) and standard data product MOD09A1 were downloaded for calculating enhanced vegetation index (EVI) and land surface water index (LSWI). Measured air temperature (Ta) and photosynthetically active radiation (PAR) data were also included for model simulating. Field CO2 flux data, during the period from May, 2003 to September, 2005, were used to estimate the 'observed' GPP (GPPobs) for validation. The seasonal dynamics of GPP predicted from VPM (GPPVPM) was compared quite well (R2=0.903, N=111, p<0.0001) with the observed GPP. The ag- gregate GPPVPM for the study period was 641.5 g C·m?2, representing a ~6% over-estimation, compared with GPPobs. Additionally, GPP predicted from other two typical production efficiency model (PEM) represents either higher overestimation or lower underestimation to GPPobs. Results of this study demonstrate that VPM has potential for estimating site-level or regional grassland GPP, and might be an effective tool for scaling-up carbon fluxes.WU WeiXing WANG ShaoQiang XIAO XiangMing YU GuiRui FU YuLing HAO YanBin 2008Science China Earth Sciences2008,51,10:13
4A theoretical model for mid-and low-latitude ionospheric electric fields in realistic geomagnetic fields显示文摘The geomagnetic fields,which play important roles in the ionospheric dynamo,can greatly affect the global distribution of ionospheric electric fields,currents and other ionospheric electrodynamics phenomena.In the study of ionospheric electrodynamics phenomena,such as the longitudinal variations of ionospheric electric fields,the non-dipolar component of the geomagnetic fields must be taken into account.In this paper,we deduce a theoretical electric field model for ionospheric dynamo at mid-and low-latitude which adopt a modified magnetic apex coordinates system.In the new electric field model,the geomagnetic fields can be calculated from either the IGRF model or the dipole field model,and the neutral winds and conductivities are calculated based on empirical models.Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method,and the ionospheric electric fields and currents are derived from the calculated potential.Our model can reproduce the main features of the ionospheric electrodynamics processes,so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.REN ZhiPeng WAN WeiXing WEI Yong LIU LiBo YU Tao 2008Chinese Science Bulletin2008,53,24:7
5Development of a middle and low latitude theoretical ionospheric model and an observation system data assimilation experiment显示文摘On the basis of previous work, we develop a middle and low latitude theoretical ionospheric model in this paper, named Theoretical Ionospheric Model of the Earth in the Institute of Geology and Geophysics, Chinese Academy of Sciences (TIME-IGGCAS). TIME-IGGCAS solves the equations of mass continuity, motion and energy of electron and ions self-consistently and uses an eccentric dipole field approxima-tion to the Earth’s magnetic field. We combine the Eulerian and Lagrangian approaches in the model and take account of the plasma E×B drift velocity. Calculation results reveal that the model is steady and credible and can reproduce most large-scale features of ionosphere. By using TIME-IGGCAS, we carried out an observation system data assimilation experiment. Assimilation results show that the E×B drift velocity can be accurately estimated by ingesting the observed foF2 and hmF2 into the model ap-plying nonlinear least-square fit method. We suggest that this work is of great significance in the de-velopment of ionospheric data assimilation model to give better nowcast and forecast of ionosphere.YUE XinAn WAN WeiXing LIU LiBo LE HuiJun CHEN YiDing YU Tao 2008Chinese Science Bulletin2008,53,1:7
6Power generation and heat sink improvement characteristics of recooling cycle for thermal cracked hydrocarbon fueled scramjet显示文摘In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle.BAO Wen QIN Jiang ZHOU WeiXing ZHANG Duo YU DaRen 2011Science China(Technological Sciences)2011,54,4:6
7Design method with controllable velocity direction at throat for inward-turning inlets显示文摘In the design of a hypersonic inward-turning inlet by applying the traditional basic flowfield, a reflected shock-wave is formed in the isolator due to the continuous reflection of the cowlreflected shock wave in the basic flow-field, which interacts with the boundary layer to produce a considerable influence on the performance of the inlet. Here, a basic flow-field design method that can control the velocity direction at the throat section is developed, and numerical simulations are conducted to demonstrate the effectiveness of this method. The method presented in this paper can achieve the absorption of the reflected waves at the shoulder of the basic flow-field by adjusting the variation law of the center radius in the basic flow-field, and a smooth transition between the compression surface and the isolator can also be produced. The Mach number and total pressure recovery coefficient of the inlet designed according to this method are 3.00 and 0.657, respectively, at design point(the incoming flow Mach number Ma1= 6.0). The results show that with this method, the inlet can efficiently weaken both the reflection of the shock wave and the interaction between the boundary layer and the reflected shock waves, which improves the aerodynamic performance of the inlet.Wenyou QIAO Anyuan YU Wei GAO Weixing WANG 2019Chinese Journal of Aeronautics2019,32,6:4
8Capability-based context ontology modeling and reasoning for C^4ISR communication显示文摘Modeling and reasoning on domain contexts play a key role for adding intelligence to communication services, and the approach of capability-based requirement engineering ensures the scientificity and accuracy of requirement elicitation. This paper presents a capability-based context ontology modeling approach for command and control, communication, computer, intelligence, surveillance and reconnaissance(C4ISR) communication. Primarily, a capability-based C^4ISR communication meta-concept model and a C^4ISR communication context meta-ontology are constructed. The context ontology is established under the constraints of the C^4ISR communication context meta-ontology, and furthermore, algorithms are proposed to support context reasoning based on description logic. A case study is presented to demonstrate applicability of the proposed method.Weixing Zhu Zhixue Wang Guolin Hou Minggang Yu 2016Journal of Systems Engineering and Electronics2016,27,4:3
9Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China显示文摘Binrui Xu Weixing Dong Chunming Yu Zhaoqing He Yanli Lv Yanzheng Sun Xiaoyu Feng Ning Li L. F. Lee Maoxiang Li 2004Avian Pathology2004,,1:3
10Anomaly detection of hot components in gas turbine based on frequent pattern extraction显示文摘Hot components operate in a high-temperature and high-pressure environment. The occurrence of a fault in hot components leads to high economic losses. In general, exhaust gas temperature(EGT) is used to monitor the performance of hot components.However, during the early stages of a failure, the fault information is weak, and is simultaneously affected by various types of interference, such as the complex working conditions, ambient conditions, gradual performance degradation of the compressors and turbines, and noise. Additionally, inadequate effective information of the gas turbine also restricts the establishment of the detection model. To solve the above problems, this paper proposes an anomaly detection method based on frequent pattern extraction. A frequent pattern model(FPM) is applied to indicate the inherent regularity of change in EGT occurring from different types of interference. In this study, based on a genetic algorithm and support vector machine regression, the relationship model between the EGT and interference was tentatively built. The modeling accuracy was then further improved through the selection of the kernel function and training data. Experiments indicate that the optimal kernel function is linear and that the optimal training data should be balanced in addition to covering the appropriate range of operating conditions and ambient temperature. Furthermore, the thresholds based on the Pauta criterion that is automatically obtained during the modeling process, are used to determine whether hot components are operating abnormally. Moreover, the FPM is compared with the similarity theory, which demonstrates that the FPM can better suppress the effect of the component performance degradation and fuel heat value fluctuation. Finally, the effectiveness of the proposed method is validated on seven months of actual data obtained from a Titan130 gas turbine on an offshore oil platform. The results indicate that the proposed method can sensitively detect malfunctions in hot components during the early stages of a fault, and is robust to various types of interference.LIU JinFu ZHU LinHai MA YuJia LIU Jiao ZHOU WeiXing YU DaRen 2018Science China(Technological Sciences)2018,61,4:2
11MicroRNA-135a contributes to the development of portal vein tumor thrombus by promoting metastasis in hepatocellular carcinoma显示文摘Shupeng Liu Weixing Guo Jie Shi Nan Li Xiya Yu Jie Xue Xiaohui Fu Kaijian Chu Chongde Lu Jiangsha Zhao Dong Xie Mengchao Wu Shuqun Cheng Shanrong Liu 2011Journal of Hepatology2011,,2:2
12GPS detection of the coseismic ionospheric disturbances following the 12 May 2008 M7.9 Wenchuan earthquake in China显示文摘Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06:28 UT on 12 May,2008.One is detected 7.9 min after the earthquake and had an intensive'N'shape oscillated waveform with a pronounced amplitude of about 1 TECU,which propagates approximately southward to the distance about 1000 km with the horizontal phase velocity of 600±84 m/s and the period of 9.5±1.3 min.The other is detected8.5 min after the earthquake and has an oscillated waveform more like a positive pulse with an amplitude of about 0.5 TECU,which propagates eastward to the distance about 800 km with the horizontal phase velocity of 720±59 m/s and the period of7.4±0.8 min.These two coseismic ionospheric disturbances are caused by the acoustic gravity waves excited by partial transformation of the acoustic waves originated from the energy release of the earthquake,somewhere near the epicenter.The directional preferences of these two coseismic ionospheric disturbances may be associated with the oblique geomagnetic field lines and the background winds filtering effect.SONG Qian DING Feng YU Tao WAN WeiXing NING BaiQi LIU LiBo ZHAO BiQiang 2015Science China Earth Sciences2015,58,1:2
13Germanium nanopyramid arrays showing near-100% absorption in the visible regime显示文摘Solar energy is regarded as one of the most plentiful sources of renewable energy. An extraordinary light-harvesting property of a germanium periodic nanopyramid array is reported in this Letter. Both our theoretical and experimental results demonstrate that the nanopyramid array can achieve perfect broadband absorption from 500- to 800-nm wavelength. Especially in the visible regime, the experimentally measured absorption can even reach 100%. Further analyses reveal that the intrinsic antireflection effect and slow-light waveguide mode play an important role in the ultra-high absorption, which is helpful for the research and development of photovoltaic devices.Qi Han Yongqi Fu Lei Jin Jingjing Zhao Zongwei Xu Fengzhou Fang Jingsong Gao Weixing Yu 2015Nano Research2015,8,7:2
14Experimental study on enhancement of the metastatic potential of portal vein tumor thrombus-originated hepatocellular carcinoma cells using portal vein serum显示文摘Objective: Portal vein metastasis of hepatocellular carcinoma(HCC) results in a poor prognosis and seriously affects the survival rate of patients. The mechanism underlying the formation of portal vein tumor thrombus(PVTT) is complex and is not yet fully understood. This study was conducted to investigate the impact of portal vein blood on the proliferation, metastasis, invasion and apoptosis of PVTT cells and to explore its possible mechanisms, which was expected to lay a foundation for ascertaining the mechanism underlying the portal vein metastasis of HCC.Methods: Peripheral blood and portal vein blood were collected from patients with HCC, and the sera from these two sources were used to culture the PVTT-originated HCC cell line CSQT-2. The cells were collected after 24 h, and flow cytometry was performed to detect cell proliferation, cell cycle stages and apoptosis. Transwell migration and invasion assays were applied to detect the metastasis and invasion of the cells in each group. The changes in the expression of MMP-2 and MMP-9 in cells were detected via Western blotting. The contents of IL-12, IFN-γ, IL-1β, IL-2 and TNF-α in the two groups of sera were quantified using corresponding kits. Results: Compared with the group of cells cultured with peripheral serum, the cells cultured with portal vein serum showed significantly lower apoptosis(P<0.01), significantly enhanced cell metastasis and invasion(P<0.01), whereas cell proliferation and the stages of the cell cycle did not differ significantly(P>0.05). A significantly increased expression level of MMP-2 has been observed in tumor cells treated portal vein serum. In addition, compared with peripheral serum, the content of IL-12 was significantly decreased in portal vein serum(P<0.05), while the contents of IFN-γ, IL-1β, IL-2, and TNF-α did not differ significantly(P>0.05). Conclusions: Portal vein serum from HCC patients could inhibit the apoptosis of PVTT-originated HCC cells and promote cell metastasis and invasion. This effect may be related to the lower level of IL-12 in portal vein serum.Yufu Tang Hongming Yu Long Zhang Kang Wang Weixing Guo Jie Shi Shupeng Liu Mengchao Wu Hongyang Wang Shuqun Cheng 2014Chinese Journal of Cancer Research2014,26,5:2
15Tracking and ray tracing equations for the target-aligned heliostat for solar tower power plants显示文摘WEI Xiudong LU Zhenwu YU Weixing 2011Renewable Energy2011,36,10:1
16Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China显示文摘Binrui Xu Weixing Dong Chunming Yu 2004Avian Pathol2004,33,1:1
17A new code for the design and analysis of the heliostat field layout for power tower system 显示文摘Wei Xiudong Lu Zhenwu Yu Weixing 2010Solar Energy2010,84,4:1
18Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China显示文摘Binrui Xu Weixing Dong Chunming Yu etal 2004Avian Pathology2004,33,1:1
19A new code for the design and analysis of the heliostat eld layout for power tower system显示文摘WEI XIULONG LU ZHENWU YU WEIXING etal 2010Solar Energy2010,,84:1
20Dynamic Characteristics of Hydrocarbon Fuel within the Channel at Supercrit- ical and Pyrolysis Condition显示文摘Regenerative cooling with fuel as the coolant is used in the scramjet engine. In order to grasp the dynamic characteristics of engine fuel supply processes, this article studies the dynamic characteristics of hydrocarbon fuel within the channel. A one-dimensional dynamic model was proved, the thermal energy storage effect, fuel volume effect and chemical dynamic effect have been considered in the model, the ordinary differential equations were solved using a 4 th order Runge-Kutta method. The precision of the model was validated by three groups of experimental data. The effects of input signal, working condition, tube size on the dynamic characteristics of pressure,flow rate, temperature have been simulated. It is found that cracking reaction increased the compressibility of the fuel pyrolysis mixture and lead to longer responding time of outlet flow. The responding time of outlet flow can reach 3 s when tube is 5 m long which will greatly influence the control performance of the engine thrust system.Meanwhile, when the inlet flow rate appears the step change, the inlet pressure leads to overshoot, the overshoot can reach as much as 100%, such highly transient impulse will result in detrimental effect on fuel pump.YU Bin ZHOU Weixing QIN Jiang BAO Wen 2017Journal of Thermal Science2017,26,6:1
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