检索结果-南通市图书馆

CO_2 Mitigation in Coal Gasification Cogeneration Systems with Integration of the Shift Reaction, CO_2 Absorption and Methanol Production

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal science 2004年第3期13卷 193-198页

作者： Yuanyuan DUAN Jin ZHANG Key laboratory of Thermal science and Power Engineering, Department of Thermal Engineering, tsinghua university, {3., china Key laboratory of Thermal science and Power Engineering Department of Thermal Engineering Tsinghua University Beijing China

Cogeneration of electricity and liquid fuel can achieve higher efficiencies than electricity generation alone in Integrated Gasification Combined Cycle (IGCC), and cogeneration systems are also expected to mitigate CO2 emissions. A proposed methanol-electricity cogeneration system was analyzed in this paper using exergy method to evaluate the specified system. A simple cogeneration scheme and a complicated scheme including the shift reaction and CO2 removal were compared. The results show that the complicated scheme consumes more energy, but has a higher methanol synthesis ratio with partial capture of *** those methanol and electricity cogeneration systems, the CO2 mitigation is not merely an additional process that consumes energy and reduces the overall efficiency, but is integrated into the methanol production.

关键词： cogeneration system methanol synthesis CO2 mitigation exergy analysis

Dense coding scheme using superpositions of Bell-states and its NMR implementation

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key laboratory for Quantum information and Measurements, Department of Physics, tsinghua university, {3., china Center for Quantum information, tsinghua university, {3., china Department of Materials science and Engineering, beijing Normal university, beijing 100875, china Testing and Analytical Center, beijing Normal university, beijing 100875, china Department of Physics, beijing Normal university, beijing 100875, china 1. Key laboratory for Quantum information and Measurements Department of Physics Tsinghua University 100084 Beijing China 2. Center for Quantum information Tsinghua University 100084 Beijing China 3. Department of Materials science and Engineering Beijing Normal University 100875 Beijing China 4. Testing and Analytical Center Beijing Normal University 100875 Beijing China 5. Department of Physics Beijing Normal University 100875 Beijing China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

A measurement error model for microarray data analysis

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2005年第7期15卷 614-620页

作者： ZHOU Yiming and CHENG Jing ( Department of Biological sciences and Biotechnology, tsinghua university, {3., china State Key laboratory of Biomembrane and Membrane Biotechnology, tsinghua university, {3., china National Engineering Research Center for beijing Biochip technology, 18 Life science Parkway, beijing 102206, china) Department of Biological sciences and Biotechnology Tsinghua University Beijing 100084 China. State Key laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing 100084 China. National Engineering Research Center for beijing Biochip technology 18 Life Science Parkway Beijing 102206 China

Microarray technology has been widely used to analyze the gene expression levels by detecting fluorescence intensity in a high throughput fashion. However, since the measurement error produced from various sources in microarray experiments is heterogeneous and too large to be ignored, we propose here a measurement error model for microarray data processing, by which the standard deviation of the measurement error is demonstrated to be linearly increased with fluorescence intensity. A robust algorithm, which estimates the parameters of the measurement error model from a single microarray without replicated spots, is provided. The model and algorithm for estimating of the parameters from a given data set are tested on both the real data set and the simulated data set, and the result has been proven satisfactory. And, combining the measurement error model with traditional Z-test method, a full statistical model has been developed It can significantly improve the statistical inference for identifying differentially expressed genes.

关键词： microarray measurement error model parameter estimation differentially expressed genes.

Optimal MAC based cooperative spectrum sensing in cognitive radio networks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(information sciences) 2012年第6期55卷 1388-1396页

作者： CHEN Zhong 1,ZHANG XianDa 1 & YANG LanJuan 2 1 State Key laboratory of Intelligent technology and Systems,tsinghua National laboratory for information science and technology,Department of Automation,tsinghua university,beijing 100084,china 2 Institute of Command Automation,PLA university of science and technology,Nanjing 210007,china 1. State Key laboratory of Intelligent technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Automation Tsinghua University Beijing 100084 China2. Institute of Command Automation PLA University of Science and Technology Nanjing 210007 China

This paper considers a cognitive radio (CR) system in non-ideal fading wireless channels and pro-poses cooperative spectrum sensing schemes based on coherent multiple access channels (MAC),serving as an alternative way to improve the cooperative spectrum sensing performance and provide space diversity for spec-trum *** statistics are transmitted using a common channel from the secondary users (SUs) to a fusion center (FC) where the global decision is *** optimal scaling factors of the proposed schemes are obtained by maximizing the detection probability under a target false alarm probability and a transmit power *** the proposed optimal MAC scheme has high computational complexity,a sub-optimal solu-tion based on maximization of the deflection coefficient (DC) is also *** results show that the proposed algorithms can significantly improve the spectrum sensing performance and approach the detection baseline.

关键词： cognitive radio (CR) spectrum sensing multiple access channel (MAC) deflection coefficient optimization

Measuring-basis-encrypted six-state quantum key distribution scheme

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2006年第1期16卷 84-89页

作者： CHEN Pan1, DENG Fuguo1, WANG Pingxiao1 and LONG Guilu1,2 (Key laboratory for Quantum information and Measurements and Department of Physics, tsinghua university, {3., china 2. Key laboratory for Atomic and Molecular Nanosciences, tsinghua university, {3., china) [a]Department of Physics Tsinghua University Key Laboratory for Quantum Information and Measurements Beijing China [b]tsinghua university Key Laboratory for Atomic and Molecular NanoSciences Beijing China

A six-state quantum key distribution scheme with measuring-basis encryption technique, which is based on the six-state protocol and the MBE protocol, is proposed. In this modified six-state quantum key distribution protocol, Alice and Bob use a control key to synchronize the use of their measuring-basis so that they always use the same measuring-basis. This modified six-state quantum key distribution protocol retains the advantage of higher security and at the same time has a higher efficiency.

关键词： quantum key distribution measuring-basis encrypted six-state security.

Transverse vibration of the blade for unmanned micro helicopter using rayleigh-ritz method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of university of science and technology {3. 2003年第6期10卷 40-43页

作者： Jungang Lii, Jiadao Wang, and Darong ChenState Key laboratory of Tribology, tsinghua university, beijing 100084, {3. Lab. of Tribology Tsinghua Univ. Beijing 100084 China

A rotor manipulation mechanism for micro unmanned helicopter utilizing the inertia and the elasticity of the rotor is introduced. The lagging motion equation of the rotor blades is established, and then the natural frequencies and mode shapes of the blade for the helicopter are studied by using beam characteristic orthogonal polynomials by the Rayleigh-Ritz method. The variation of natural frequencies with the speed of rotation and the mode shapes at different rotational speeds are plotted. The using of orthogonal polynomials for the bending shapes enables the computation of higher natural frequencies of any order to be accomplished without facing any difficulties.

关键词： rotor manipulation mechanism rotor blades Rayleigh-Ritz method

A stochastic policy search model for matching behavior

在线全文

学校读者我要写书评

暂无评论

science china(information sciences) 2011年第7期54卷 1430-1443页

作者： CHENG ZhenBo 1,2,ZHANG Yu 1 & DENG ZhiDong 1 1 State Key laboratory on Intelligent technology and Systems,tsinghua National laboratory for information science and technology,Department of Computer science,tsinghua university,beijing 100084,china 2 Department of Computer science and technology,Zhejiang {13. of technology,Hangzhou 3.0014,china 1. State Key laboratory on Intelligent technology and Systems Tsinghua National Laboratory for Information Science and Technology Department of Computer Science Tsinghua University Beijing 100084 China2. Department of Computer Science and Technology Zhejiang University of Technology Hangzhou 310014 China

The matching law is one of the basic empirical laws in decision theory,and it states that a subject’s preference to optional targets depends on which choices are *** this paper,we study the possible mechanisms that explain why subjects’ decisions often obey this *** the basis of reinforcement learning theory,we put forward a decision-making model in which the policy is updated by a policy parameter,and the model might be implemented in the brain through the prefrontal cortex and the basal ganglia neural *** on this model,an algorithm that satisfies the matching law is derived under some simple *** analysis and simulation results show that the decision behavior achieved by the algorithm obeys the matching *** addition,the matching behaviors in two classical experiments are reproduced using the *** results provide a reasonable strategy for the matching law and a useful computational tool for rewarded decision-making tasks.

关键词： policy model matching law reinforcement learning decision-making model

Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3.& ZHANG XiaoZhong4,5 1 Key laboratory of Beam technology & Materials Modification of the Ministry of Education, Institute of Low Energy Nuclear Physics, beijing Normal {3., beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3.laboratory of Optical Physics, Institute of Physics, Chinese Academy of sciences, beijing 100080, china 4 Key laboratory of Advanced Materials of the Ministry of Education, Department of Materials science and Engineering, tsinghua university, beijing 100084, china 5 beijing National Center for Electron Microscopy, tsinghua university, beijing 100084, china 1. Key laboratory of Beam technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China 2. beijing Radiation Center Beijing 100875 China 3. laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China 4. Key laboratory of Advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing 100084 China 5. beijing National Center for Electron Microscopy Tsinghua University Beijing 100084 China

The LaMn1-xTexO3.δ (x=0.1, 0.2, 0.3. were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3. ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3. and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3. is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3. is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

Plant protein kinase genes induced by drought, high salt and cold stresses

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2000年第13期45卷 1153-1157页

作者： LIU Qiang , ZHANG Yong & Chen Shouyi1. Deparlmenl of Biological science and Biotechnology, tsinghua university, {3., china 2. Department of Biological science and Biotechnology, Slate Key laboratory of Biomembrane and Membrane Biotechnology, tsinghua university, {3., china 3. Institute of Genetics, Chinese Academy of sciences, {13. 100101, china Department of Biological science and Biotechnology Tsinghua University Beijing China Department of Biological science and Biotechnology State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China Institute of Genetics Chinese Academy of Sciences Beijing China

Drought, high salt and cold are three different kinds of environment stresses that severely influence the growth, development and productivity of crops. They all decrease the water state of plant cells, and consequently result in the harm of plant from water deficit. Several genes encoding protein kinases and induced by drought, high salt and low temperature have been isolated from Arabidopsis. These protein kinases include receptor protein kinase (RPK), MAP kinases, ribosomal-protein kinases and transcription-regulation protein kinase. The expression features of these genes and the regulatory roles of these protein kinases in stress response and signal transduction are discussed.

关键词： protein kinase environment stress signal transduction gene expression.