检索结果-南通市图书馆

SNMS: an intelligent transportation system network architecture based on WSN and P2P network

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 65-70页

作者： li li liu yuan-an TANG Bi-hua Wireless Center Beijing University of posts and TelecommunicationsBeijing 100876 China

With the development of city road networks, the question of how to obtain information about the roads is becoming more and more important. In this article, sensor network with mobile station （SNMS）, a novel two-tiered intelligent transportation system （ITS） network architecture based on wireless sensor network （WSN） and peer-to-peer （P2P） network, is proposed to provide significant traffic information about the road and thereby, assist travelers to take optimum decisions when they are driving. A detailed explanation with regard to the strategy of each level as well as the design of two main components in the network, sensor unit （SU） and mobile station （MS）, is presented. Finally, a representative scenario is described to display the operation of the system.

关键词： SNMS WSN P2E SU MS

NUMERICAL SIMULATION OF FLOW OF PULP FIBER SUSPENSIONS IN STOCK PUMP WITH SEMI-OPEN IMPELLER

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2005年第4期18卷 546-549页

作者： li Hong yuan Shouqi liu Weiwei Research Center of Fluid Machinery Engineering and Technology Jiangsu University Zhenjiang 212013 China

The flow of pulp fiber suspensions with a consistency below 5% through a pump falls into the turbulent region. The 2-phase 3D turbulent flow of the mixture is simulated in the hydraulic components composed by suction chamber, front board, semi-impeller and volute casing for the first time. The pseudo-fluid model and the k-ε turbulent model are modified. Phase coupled SIMPLE algorithm is applied to make pressure-velocity correction equation. Based on the results of the numerical simulation, the distribution of velocity, pressure and density of liquid and particle phase are compared and analyzed. The flow analysis in the tip between front board and impeller is emphasized, which reflects the advantage of semi-open impeller when it transports 2-phase medium. This calculation result will be helpful for the design of pump impeller and the establishment of design method of centrifugal stock pump.

关键词： Centrifugal stock pump Pulp fiber suspensions Numerical simulation

Pricing in combinatorial double auction-based grid allocation model

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 59-65页

作者： li li liu yuan-an liu Kai-ming MA Xiao-lei YANG Ming Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This article proposes a novel grid resource allocation model, in which the users and the grid service providers participate in the combinatorial double auction for the resource allocation. To obtain the detailed resource allocation status and the price information, a novel pricing algorithm is designed for the allocation model. Simulation results demonstrate that the proposed algorithm completes the resource allocation and pricing efficiently, and exhibits incentive compatible characteristic. Moreover, users with the higher average price and providers with the lower average price get compensation during the pricing process.

关键词： grid combinatorial double auction resource allocation pricing

Time and Temperature Dependence of the Structural Evolution for Polyamide 1012

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2020年第9期38卷 993-998,I0007页

作者： Xin-Ran liu Yu Wang li-yuan liu Xia Dong Du-Jin Wang CAS Key Laboratory of Engineering Plastics CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China

The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been *** results show that the viscosity increases and crosslinking reaction occurs simultaneously together with the increase of temperature,thus causing the variation of storage modulus(G')and loss modulus(G")in the repeated frequency sweeps with residual *** research has pointed out that the superposition is valid for monitoring the complex behavior composed of the viscosity increasing and crosslink occurring process by tracing the variation behavior of the crossover points of G'and G"with time,revealing the same time-temperature dependence of the two reactions in the isothermal process.A normalized master curve has been proposed to describe the melt behavior at a given temperature.

关键词： Polyamide 1012 Rheology Crosslinking Viscosity increasing Time-temperature superposition

Temperature-induced dissociation reaction and dynamics of light-harvesting complex II isolated from purple photosynthetic bacterium ***

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第8期52卷 1029-1035页

作者： FENG Juan li XueFeng liu yuan School of life Science and Technology University of Electronic Science & Technology of China Chengdu 610054 China

Steady-state absorption spectroscopy,circular dichroism,and resonance Raman spectroscopy have been used to investigate the thermal stability of LH2 complex isolated from purple photosynthetic bacterium *** results show that:1)upon increasing the temperature,a transition from B800 and B850 to free bacteriochlorophyll(B780)happens;2)a gradual decrease and disappearance of CD signal in visible region occur;3)a shift of the frequency,belonging to C==C and C—C stretching vibration,to higher wavenumber takes *** is suggested that LH2 complex can be dissociated in the presence of B800,B850 and carotenoids ***-exponential fitting on the dynamic decay curves gives the apparent time constants of hundreds of minutes for various pigments.

关键词：紫色光合细菌沼泽红假单胞菌温度诱导离解反应反应动力学捕光配合物Ⅱ

Molecular Characterization of Three Ethylene Responsive Element Binding Factor Genes from Cotton

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2010年第5期52卷 485-495页

作者： Long-Guo Jin Hui li Jin-yuan liu Laboratory of Molecular Biology and MOE Laboratory of Protein Science Department of Biological Sciences and Biotechnology TsinghuaUniversity Beijinq 100084 China

Ethylene-responsive factors （ERFs） are important regulators of plant gene expression. In this study, three novel ERF genes, GhERF2, GhERF3 and GhERF6, were isolated from cotton （Gossypium hirstum） using rapid amplification of cDNA ends-polymerase chain reaction. Transient expression analysis using GhERF-green fluorescent protein fusions showed that these three proteins were targeted to the nucleus. Fusion proteins consisting of GhERF2, GhERF3 or GhERF6 coupled to the GAL4 DNA binding domain strongly activated transcription in yeast. Furthermore, GhERF6 was shown to be able to bind specifically to GCC boxes using a particle bombardment assay in tobacco cells. Semi-quantitative reverse transcription-polymerase chain reaction revealed that GhERF2 and GhERF3 are constitutively expressed in all organs, while GhERF6 is only constitutively expressed in vegetative organs. When plants were treated with ethylene, abscisic acid, salt, cold and drought, the transcripts of GhERF2, GhERF3 and GhERF6 were rapidly induced to high levels. Promoter analysis also indicated that the 5＇ upstream regions of the three genes possess elements induced by these physiological and environmental factors. Collectively, our data suggest that GhERF2, GhERF3 and GhERF6 might function as positive trans-acting factors in the plant responses to ethylene, abscisic acid and other stresses and provide useful clues for further research into the mechanism of them in regulating cotton multiple stress responses.

关键词： PLANT gene expression COTTON POLYMERASE chain reaction ETHYLENE ABSCISIC acid

Power control for two-way amplify-and-forward relaying over Rayleigh fading channels

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第4期12卷 280-287页

作者： Xing-zheng li yuan-an liu Gang XIE Pan-liang DENG Fang liu School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

We propose two novel power control policies for a two-way amplify-and-forward (AF) relaying system,in which each node (two sources and one relay) is assumed to operate under bothminimum and peak power *** the exploitation of instantaneous channel gains,the first policy can maximize the sum rate of the ***,the instantaneous channel gains may be unavailable in a rapid time-varying system,where the first policy is ***,a robust power control policy which requires only mean channel gains is proposed to maximize the upper bound of the average sum rate,and the properties of this policy are *** results show that,by comparison with the policy in which all the nodes use their peak transmit power,the proposed power control policies can provide considerable system performance ***,the performance difference between the two proposed policies is negligible when the relay is close to one source.

关键词： Amplify-and-forward (AF) relaying Power control Two-way relay channel Bidirectional relaying Cooperative communication

RNA解旋酶DDX5:细菌性炎症反应的调节器

在线全文

学校读者我要写书评

暂无评论

中国兽医科学 2024年第6期54卷 852-852页

作者： Jian Xu li-yuan liu Fei-Jie Zhi Yin-Juan Song Zi-Hui Zhang Bin li Fu-Ying Zheng Peng-Cheng Gao Su-Zi Zhang Yu-Yu Zhang Ying Zhang Ying Qiu Bo Jiang Yong-Qing li Chen Peng Yue-Feng Chu State Key Laboratory for Animal Disease Control and Prevention College of Veterinary Medicine Lanzhou University Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou China. National Key Laboratory of Veterinary Public Health College of Veterinary Medicine China Agricultural University Beijing China. College of Veterinary Medicine Xinjiang Agricultural University Urumqi China. State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences University of Chinese Academy of Sciences Shanghai China. Institute of Animal Husbandry and Veterinary Medicine Beijing Academy of Agriculture and Forestry Sciences Beijing China. National Key Laboratory of Veterinary Public Health College of Veterinary Medicine China Agricultural University Beijing China. pengchenea@***. State Key Laboratory for Animal Disease Control and Prevention College of Veterinary Medicine Lanzhou University Lanzhou Veterinary Research Institute Chinese Academy of Agricultural Sciences Lanzhou China. chuyuefeng@***.

细菌性感染是威胁动物和人类健康的重要原因之一,国际著名医学杂志《柳叶刀》发表的一项研究表明,金黄色葡萄球菌、大肠杆菌、肺炎链球菌、支原体等33种常见细菌感染是2019年全球人类第二大死亡原因,与全球八分之一的死亡有关,减少细菌... 详细信息

细菌性感染是威胁动物和人类健康的重要原因之一,国际著名医学杂志《柳叶刀》发表的一项研究表明,金黄色葡萄球菌、大肠杆菌、肺炎链球菌、支原体等33种常见细菌感染是2019年全球人类第二大死亡原因,与全球八分之一的死亡有关,减少细菌感染已成为全球公共卫生的优先事项。研制细菌感染防控技术和制定有效防控策略,离不开对细菌致病和免疫机制的深度解析。病原菌与宿主间存在双向、动态、复杂的相互作用,其中甲基化、泛素化等表观遗传修饰在病原菌与宿主互作的过程中发挥了重要作用.

关键词：细菌感染防控技术细菌性感染免疫机制肺炎链球菌防控策略金黄色葡萄球菌 RNA解旋酶

Generating 0.42 THz radiation from a second harmonic gyrotron

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第28期56卷 3572-3574页

作者： FU WenJie YAN Yang li XiaoYun yuan XueSong liu ShengGang Terahertz Research Center School of Physical Electronics University of Electronic Science and Technology of China Chengdu 610054 China

Gyrotrons are high powered coherent electromagnetic radiation sources, and are considered to be available powerful sources that have the potential to bridge the so-called terahertz gap. In the University of Electronic Science and Technology of China, a second harmonic gyrotron has been designed, manufactured, and tested. The gyrotron generated radiation at a 0.423 THz frequency in 5μs pulses with an 8.1 Tesla magnetic field, with a power per pulse of about 4.4 kW. To date this is the highest frequency recorded for vacuum electronic devices in China. The gyrotron design, operation and measurements are presented.

关键词： THz辐射二次谐波回旋管电子科技大学真空电子器件中国科技脉冲功率出现频率