检索结果-南通市图书馆

Subsidence control and farmland conservation by solid backfilling mining technology

中国有色金属学会会刊：英文版 2011年第S3期21卷 665-669页

作者： GUO Guang-li1, 2, FENG Wen-kai3. ZHA Jian-feng1, 2, 3. LIU Yuan-xu1, 2, WANG Qiang1, 2 1. Key Laboratory for Land Environment and Disaster Monitoring of the State Bureau of Surveying and Mapping, china university of Mining and Technology, Xuzhou 221116, china 2. Jiangsu Key Laboratory of Resources and Environmental {3. Engineering, china university of Mining and Technology, Xuzhou 221116, china 3. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu university of Technology, Chengdu 610059, china Key Laboratory for Land Environment and Disaster Monitoring of the State Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China Jiangsu Key Laboratory of Resources and Environmental information Engineering China University of Mining and Technology Xuzhou 221116 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining technology, which decreases the height of fissure zone and caving zone, and alleviates the subsidence, is a new technology for farmland conservation. Based on the situation analysis of farmland destruction in mining area, three ways for farmland protection were proposed. In order to improve the feasibility of this technology, the limited filling materials should be used to increase resources recovery ratio, and then the surplus materials could be backfilled into goaf. An index, namely farmland conservation ability, was put forward to optimize the ways for farmland conservation. At last, the Wanbei coal mine was taken as a case for farmland conservation. It was shown that 3.40 t dull coal was substituted and 52 hm2 farmland was conserved by solid backfilling mining in this coal mine.

关键词： solid backfilling farmland conservation mining subsidence equivalent mining height

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study On communication Scheduling of Fieldbus

Study On Communication Scheduling of Fieldbus

引用

2009中国控制与决策会议

作者： Zhang Xiang-li information & communication College,guilin {3. of electronic Technology,541004 guilin,Guangxi,P.R.china

＜正＞The communication tasks of fieldbus system often include the information transfer among the field devices. However,fieldbus is not an absolute system,which is a component of entire ***,as to fieldbus scheduling,not only the communication tasks of fieldbus but also the restrains from the other tasks in the system should be *** this paper,a dynamic fieldbus scheduling algorithm is used to cope with the dynamic scheduling of the task system including cyclic real-time tasks,acyclic real-time tasks,non-real-time tasks and time slot tasks under distributed multi-processor *** model of the task system is presented and the algorithm is *** last,a real-time communication scheduling of computer numerical control（CNC） fieldbus system is illustrated to apply the algorithm,and the time and space cost of this algorithm is analyzed.

关键词： Fieldbus communication Task Scheduling Multi-processor

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Two possible mechanisms for vortex self-organization

引用

Science china Earth Sciences 2006年第2期49卷 202-211页

作者： LUO Zhexian2, ZHOU Xiuji1 & GAO Shouting3.1. Chinese Academy of Meteorological Sciences, Beijing 100081, china 2. Department of Space information Science, Nanjing university of information Science and Technology, Nanjing 210044, china 3. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china Department of Environmental Science Nanjing University of Information Science and Technology Nanjing China Chinese Academy of Meteorological Sciences Beijing China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The vortex self-organization is investigated in this paper by four groups of numerical experiments within the framework of quasi-geostrophic model, and based on the experimental results two types of possible mechanisms for vortex self-organization are suggested. The meso-scale to-pography may enable separated vortices to merge into a larger scale vortex; and the interaction of meso-γ and meso-β scale systems may make separated vortices to self organize a typhoon-like vor-tex circulation.

关键词： vortex, self-organization, meso-scale topography, interaction of different scales.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

引用

Science china(information Sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3.1Department of electronic and information Engineering, Zhejiang Institute of Media and communications, Hangzhou 3.0018,{3. 2Department of information Engineering, Jiangsu City Vocation College, Nanjing 21003.,{3. 3.ollege of communication and information Engineering, Nanjing university of Posts and Telecommunications, Nanjing 210003.{3. Department of electronic and information Engineering Zhejiang Institute of Media and Communications Hangzhou China Department of information Engineering Jiangsu City Vocation College Nanjing China College of communication and information Engineering Nanjing University of Posts and Telecommunications Nanjing China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-scale Interfacial Friction Behavior between Two Kinds of Materials in MEMS Based on Molecular Dynamics Simulations

引用

Journal of Wuhan university of Technology(Materials Science) 2006年第4期21卷 173-176页

作者：杨平 Research Center of Micro-Nano Science and Technology Jiangsu University Zhenjiang 212013ChinaResearch Center of Advanced Design & Manufacturing Guilin Institute of Electronic Technology Guilin 541004 China

The aim of this article was to provide a systematic method to perform molecular dynamics simulotion or evaluation for nano-scale interfacial friction behavior between two kinds of materials in MEMS design. Friction is an important factor affecting the performance and reliability of MEMS. The model of the nano-scale interracial friction behavior between two kinds of materials was presented based on the Newton＇ s equations of motion. The Morse potential function was selected for the model. The improved Verlet algorithm was employed to resolve the model, the atom trajectories and the law of the interfacial friction behavior. Comparisons with experimental data in other paper confirm the validity of the model. Using the model it is possible to simulate or evaluate the importance of different factors for designing of the nano-scale interfacial friction behavior between two kinds of materials in MEMS.

关键词： molecular dynamics simulation interfacial friction nano-scale friction MEMS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal user scheduling and power control in multi-user cognitive broadcast systems

引用

Science china(information Sciences) 2012年第6期55卷 1402-1414页

作者： WANG QunHuan 1,2,3.WANG HuiMing 1,2,3.& YIN QinYe 1,3.1 school of electronic and information Engineering,Xi'an Jiaotong {3.,Xi'an 710049,china 2 State Key Lab for Integrated Services Networks,Xidian {3.,Xi'an 710071,china 3.Ministry of Education Key Lab for Intelligent Networks and Network Security,Xi'an Jiaotong {3.,Xi'an 710071,china. school of electronic and information Engineering Xi’an Jiaotong University Xi’an China State Key Lab for Integrated Services Networks Xidian University Xi’an China Ministry of Education Key Lab for Intelligent Networks and Network Security Xi’an Jiaotong University Xi’an China

Cognitive radio systems should not only have the ability to sense and exploit "frequency spectrum holes",but also the ability to sense and utilize "spatial spectrum holes".In this paper,we consider the issue of maximizing the throughput of the cognitive systems by fully utilizing "spatial spectrum holes" brought in by multiple cognitive users,in the scenario where a pair of licensed users and a cognitive broadcast system share multiple spectrum *** exploiting the channel reciprocity under the premise that the licensed system adopts the time-division-duplexing (TDD) mode,we propose a more practical cognitive access scheme that can sense the interference at the licensed user caused by the cognitive transmitter,based on the existing feedback signals from the licensed user to the licensed base *** both interferences from the licensed base station to the cognitive receiver and from the cognitive transmitter to the licensed user into consideration,we investigate the optimal user scheduling and power allocation scheme that can maximize the ergodic sum rate of the cognitive *** show that scheduling the user whose channel gain to interference and noise ratio (CGINR) is the largest for each frequency band is *** also derive the dynamic power allocation scheme meeting the three practical constraints,i.e.,the transmitter's average transmission power constraint,the power amplifier's instantaneous transmission power constraint,and the interference power constraint at the licensed *** result shows that in different coherent time intervals and different frequency bands,the power allocation has a multi-level waterfilling *** analysis shows that the strategy scheduling user with the largest CGINR introduces significant performance improvement compared with the traditional strategy scheduling user with the largest channel gain to noise ratio (CGNR).We also illustrate the impact of power constraints and the number of users on system p

关键词： cognitive radio distributed spatial spectrum holes opportunistic scheduling power allocation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Vision navigation algorithm for mine agent based on quaternion

引用

中国有色金属学会会刊：英文版 2011年第S3期21卷 610-615页

作者： LI Ke-zhao1, 4, LEI Wei-wei1, 2, GUO Zeng-zhang1, 2, WU Li-xin3. ZHANG Qin4 1. school of Survey and Land information Engineering, Henan Polytechnic university, Jiaozuo 454003.{3. 2. Key Laboratory of Mine Spatial information Technologies of State Bureau of Surveying and Mapping, Henan Polytechnic university, Jiaozuo 454003.{3. 3. College of Resources and Civil Engineering, Northeastern university, Shenyang 110819,{3. 4. College of Geology Engineering and Geomatics, Chang’an university, Xi’an 710054,{3. school of Survey and Land information Engineering Henan Polytechnic University Jiaozuo 454003 China College of Geology Engineering and Geomatics Chang'an University Xi'an 710054 China Key Laboratory of Mine Spatial information Technologies of State Bureau of Surveying and Mapping Henan Polytechnic University Jiaozuo 454003 China College of Resources and Civil Engineering Northeastern University Shenyang 110819 China

Autonomous relative navigation is the key technology in mining or rescuing. On the basis of mine requirement and the theories of machine vision, an autonomous relative navigation algorithm for mine agent based on quaternion was proposed. In rotation transformation, this algorithm was represented by using quaternion. Because the Jacobi matrix of this method is lower than that of Hall algorithm, the calculation efficiency is improved by using this algorithm. The results of these experiments show that the computation burden of this algorithm based on quaternion is about half that of Hall algorithm. This algorithm based on quaternion is improved as a valid way to solve the problem of mine real-time navigation.

关键词： quaternion mine agent vision navigation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

electronic structure and magnetism of Fe-doped SiC nanotubes

引用

Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2,3.ZHANG FuChun3.ZHANG ZhiYong4,LU ShuYuan5 & YANG YanNing3.1 Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710068,china 2 Graduate university of Chinese Academy of Sciences,Beijing 100049,china 3.College of Physics and {3. information,Yan’an university,Yan’an 716000,china 4 information Science and Technology Institution,Northwest university,Xi’an 710127,china 5 Department of Telecommunications,Xi’an Institute of Posts and Telecommunications,Xi’an 710121,china Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an China Graduate university of Chinese Academy of Sciences Beijing China College of Physics and electronic information Yan’an University Yan’an China information Science and Technology Institution Northwest University Xi’an China Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an China

The electronic structure and magnetic properties of Fe-doped SiC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LSDA).The calculation results indicate that the SiC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2 eV lower than that of antiferromagnetic *** atoms are more likely to replace Si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of SiC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for Si,obviously there are spin-split and intense p-d hybrid effects by Si 3. electron spins and Fe 3. electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3. electrons of Fe *** these results show that the transition metal doping SiC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： SiC nanotube the first-principles doped magnetic properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic and dielectric properties of low temperature fired ferrite/ceramic composite materials

引用

Progress in Natural Science:Materials International 2011年第1期21卷 21-26页

作者： Wei-wei LING~(1,2),Huai-wu ZHANG~1,Ying HE~1,Yuan-xun LI~1,Yun-yan WANG~1 1.State Key Laboratory of electronic Thin Films and Integrated Devices, university of electronic Science and Technology of{3.,Chengdu 610054,china 2.Department of communication Engineering,Chengdu university of information Technology, Chengdu 610225,china State Key Laboratory of electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China Department of communication Engineering Chengdu University of Information Technology Chengdu 610225 China

Ni-Cu-Zn ferrite/CaTiO3.nd Ni-Cu-Zn ferrite/BaTiO3.omposites which can be applied in low temperature co-fired ceramic（LTCC） technology were synthesized by conventional solid-state reaction at temperature lower than 950℃.Influence of the microstructures and the gap parameterδ/D on the complex permeability of the above two composites was *** modifiedδ/D values of the above two composites show a good fit to the magnetic circuit *** dielectric properties of the composites were predicted by the Maxwell-Garnctt effective medium theory and the discrepancy between measured and calculated values was analyzed.

关键词： ferrite/ceramic composite low temperature co-fired ceramic(LTCC) solid-state reaction magnetic properties dielectric properties

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Threshold quantum secure direct communication without entanglement

引用

Science china(Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3.& WEN QiaoYan2 1 College of Computer Science and Technology, Beijing university of Technology, Beijing 100022, china 2.school of Science, Beijing university of Posts and Telecommunications, Beijing 100876, china 3.State Key Laboratory of information Security (Graduate school of Chinese Academy of Sciences), Beijing 100049, china College of Computer Science and Technology Beijing University of Technology Beijing China State Key Laboratory of information Security (Graduate school of Chinese Academy of Sciences) Beijing China school of Science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：