检索结果-南通市图书馆

Photonic band gap from periodic structures containing anisotropic nonmagnetic left-handed metamaterial

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2010年第4期8卷 431-434页

作者：唐婷婷陈福深孙豹 key laboratory of Broadband Optical Fiber Transmission and Communication Networks in University of Electronic Science and Technology of china Ministry of Education Department of Optoelectronic Technology Chengdu University of Information Technology key laboratory of Broadband Optical Fiber Transmission and Communication Networks in University of Electronic Science and Technology of china Ministry of Education

We demonstrate a photonic band gap（PBG） from one-dimensional（1D） periodic structures created by a double-layer unit cell with an air layer and an anisotropic nonmagnetic left-handed metamaterial（LHM） layer whose permittivity elements are partially *** requirements imposed on the materials and structures to realize a PBG are derived when the frequency is above or below the cutoff frequency,and the transmission properties of the PBG are discussed by utilizing 4×4 transfer-matrix method with dispersive semiconductor metamaterial.

关键词： Anisotropy Cutoff frequency Energy gap Metamaterials Photonic band gap Transfer matrix method

A Power Line-delivered and Lamp-based Broadband Mobile Communication System

在线全文

学校读者我要写书评

暂无评论

ZTE communications 2007年第3期5卷 28-31页

作者： Tang Youxi Shao Shihai (national key Lab of communications,UESTC,chengdu 610054,china)

A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadband mobile communications. The architecture introduces the Information Lamp (IL),a novel device carrying out transceiver function,as the access point,besides providing light. It fulfills information interaction between the access points and radio access network through the power line (or fiber). The new system,supported by core technologies such as multi-antenna based distributed space-time signal processing and distributed radio resource management,integrates the wired and wireless networks to provide high-speed and high-quality mobile communication services.

关键词： MIMO line A Power Line-delivered and Lamp-based Broadband Mobile Communication System Access

Research on Water Resources Conservation of Mountain River Based on the Concept of Region Partition

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第4期8卷 582-591页

作者： LIU Yubang TAO Qingyu LIANG Chuan WU Yong State key laboratory of Geohazard Prevention and Geoenvironment Protection chengdu University of Technology Chengdu 61o059 China State key laboratory of Hydraulics and Mountain River Engineering College of Water Resource & Hydropower Sichuan University Chengdu 61oo65 China Academic Journal Center of chengdu University of Technology Chengdu 61oo59 China

Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious *** mountain ecosystems play a key role in water resources conservation of mountain rivers,and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution,partition theory can be applied to the water resources conservation of mountain *** theory observes the following partition principles:regional relativity,spatial continuity,integralcounty,meeting management needs,hierarchical principle,and comparability *** it lays equal emphasis on both water resources conservation and environmental protection,on both water quality conservation and water quantity protection,on the combination of water features,water cycle and water *** the partition methods,index method and map superposition method will be applied in region *** example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers,and it provides a platform for future study in water resources conservation.

关键词： Water resources conservation Mountain river Region partition Mountain ecosystems

PIXE and INAA studies on ancient potteries from Guangfulin relics in Shanghai

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1348-1356页

作者： Lin Jiawei1, Cheng Huansheng1, Zhang Zhengquan1, Zhang Bin1, Feng Songlin2, Song Jian3, Gao Menghe4 and Zhu Dan1(1. Applied Ion Beam Physics laboratory, key laboratory of the Ministry of Education, Institute of modern Physics, Fudan University, Shanghai 200433, china 2. key laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Beijing 100039, china 3. Shanghai Museum, Shanghai 200003, china 4. Department of Cultural Heritage and Museology, Fudan University, Shanghai 200433, china) Applied Ion Beam Physics laboratory Institute of Modern Physics Fudan University Shanghai 200433 China key laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Beijing 100039 China Shanghai Museum Shanghai 200003 China Department of Cultural Heritage and Museology Fudan University Shanghai 200433 China

This paper reports the study of ancient potteries unearthed from the Guangfulin site in Shanghai. From the external features of these potteries, archeologists can classify them into two different cultural types: Liangzhu culture (local culture) and a new culture which might be derived elsewhere, but they can not recognize whether they were produced in the same place. Proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA) were used to measure the chemical compositions of the samples and the results were analyzed using multivariate statistics. We found that the two methods can complement each other and their database can be mutually referenced in the study of ancient potteries. Experimental results show that the compositions of the potteries from the two cultural types are different, which means that the materials for ancient potteries of new culture originate from elsewhere. This supports the archaeologists’ speculation that a group of ancient people migrated to Shanghai from some other places 4000 years ago.

关键词： PIXE INAA factor analysis Guangfulin ancient pottery

What does the Sun tell and hint now?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2009年第9期9卷 959-965页

作者： Ke-Jun Li1,2 1 national Astronomical Observatories /Yunnan Observatory,Chinese Academy of Sciences,Kunming 650011,china 2 key laboratory of Solar Activity,national Astronomical Observatories,Chinese Academy of Sciences,Beijing 100012,china national Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China key laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Some historical records, which have held since the beginning of modern solar activity cycles, are being broken by the present Sun： cycle 23 records the longest cycle length and fall time; latitudes of high-latitude sunspots belonging to a new cycle around the minimum time of the cycle are statistically the lowest at present, compared with those of other cycles; there are only one or no sunspots in a month appearing at high latitudes for 58 months, which is the first time that such a long duration has been observed. The solar dynamo is believed to be slowing down due to：（1） the minimum smoothed monthly mean sunspot number is the smallest since cycle 16 onwards, and even probably among all modern solar cycles; and （2） once the time interval between the first observations of two neighboring sunspot groups is larger than 14 d, it should be approximately regarded as an observation of no sunspots on the visible solar disk, called a spotless event. Spotless events occur with the highest frequency around the minimum time of cycle 24, and the longest spotless event also appears around the minimum time for observations of the Sun since cycle 16. Cycle 24 is expected to have the lowest level of sunspot activity from cycle 16 onwards and even probably for all of the modern solar cycles.

关键词： Sun: activity -- Sun: general -- sunspots

EFFECT OF PROCESSING METHOD ON THE IMPACT STRENGTH OF POM/TPU/CaCO_3 TERNARY COMPOSITES

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2005年第5期23卷 531-537页

作者： Xiao-ling Gao Cheng Qu Qin Zhang Rong-ni Du and Qiang Fu Department of Polymer Science & Materials,Sichuan University,State key laboratory of Polymer Materials Engineering,chengdu 610065,china Department of Polymer Science & Materials Sichuan University State Key Laboratory of Polymer Materials Engineering Chengdu 610065 China

Polyoxymethylene （POM）/elastomer/filler ternary composites were prepared, in which thermoplastic polyurethane （TPU） and inorganic filler, namely, CaCO3, were used to achieve balanced mechanical properties of POM. The dispersion and phase morphology of POM/elastomer/filler composites were found to depend largely on processing method, CaCO3 content in masterbatch and the filler size. Two processing methods were employed to prepare POM/elastomer/filler ternary composites. One is called the one-step method, in which elastomer and the filler directly melt blended with POM matrix. The other is called the two-step method, in which the elastomer and the filler were mixed to get masterbatch first, which was then melt blended with pure POM of different content. The effect of phase morphology and processing method on impact strength was investigated. It was found that the two-step method results in an increase in impact strength but not for the one-step method. Additionally, the impact strength of POM ternary composites decreases with the increase in the size of CaCO3 particles.

关键词： POM/TPU/CaCO3 composites Core-shell structure Impact strength.

Metallic photonic crystals for terahertz tunable filters

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第1期55卷 72-78页

作者： FAN Fei,CHANG ShengJiang&HOU Yu Institute of modern Optics,Nankai University,key laboratory of Optical Information Science and Technology,Ministry of Education,Tianjin 300071,china Institute of modern Optics Nankai University Key Laboratory of Optical Information Science and Technology Ministry of Education Tianjin China

We have investigated the photonic band gap and transmission properties of metallic photonic crystals(PCs)filled with liquid crystal(LC)in the terahertz region by using the finite element method and the finite-dierence time-domain *** calculations on the LC-filled metallic PC and metallic PC waveguide demonstrated that they can realize low-loss broadband terahertz tunable filters,which have a tunable range of about 110 GHz and extinction ratio larger than 35 ***,the 3 dB bandwidths of the filters keep *** designed filters based on the metallic PC can greatly improve the performances in terms of loss,bandwidth and tunable region compared to those based on the LC-filled dielectric PC.

关键词： terahertz metallic photonic crystals liquid crystals filter

Preparation of micro-patterned surfaces of Si-N-O films and their influence on adhesion behavior of endothelial cells

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(Technological Sciences) 2010年第1期53卷 257-263页

作者： ZHENG Nan,YANG Ping,WANG QiYi,YANG ZhongHai & HUANG Nan key laboratory of Advanced Technology for Materials of Education Ministry,key laboratory of Artificial Organ Surface Engineering of Sichuan,School of Materials Science and Engineering,Southwest Jiaotong University,chengdu 610031,china key laboratory of Advanced Technology for Materials of Education Ministry Key Laboratory of Artificial Organ Surface Engineering of Sichuan School of Materials Science and Engineering Southwest Jiaotong University Chengdu China

Microgrooves were prepared on Si(100) surface by photolithography and wet ***,Si-N-O films were deposited on the microgrooves by unbalanced magnetron sputtering(UBMS) and micro-patterned surfaces of Si-N-O films were *** size of the micropatterns was measured by surface *** chemical composition of Si-N-O films were characterized by X-ray photoelectron spectrometry(XPS) and the wettability of the micropatterned surfaces was evaluated by contact angle *** behavior of endothelial cells adhered on the micro-patterned surfaces,including cells adhesion,proliferation and orientation,was evaluated by cell culture test and Alamar blue *** results showed that the amount and activity of endothelial cells on micro-patterned samples were higher than those on flat *** one day's incubation,the cells were well guided along the *** days later,most of the cells grew across the grooves and contacted each *** activity was also much higher than that on flat *** was suggested that the adhesion and proliferation of endothelial cells could be effectively enhanced by micropattern method.

关键词： micropatterns Si-N-O film endothelial cell unbalanced magnetron sputtering

A Novel Missense Mutation(L296Q)in Cholesteryl Ester Transfer Protein Gene Related to Coronary Heart Disease

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第1期36卷 33-36页

作者： Ke-Qin ZHENG, Si-Zhong ZHANG, Li ZHANG, De-Jia HUANG, Lin-Chuan LIAO, and Yi-Ping HOU ( Department of Medical Genetics, West china Hospital Division of Human Morbid Genomics, key laboratory ofBiotherapy of Human Diseases of Ministry of Education, Sichuan University, chengdu 61004., china Department of Cardiology, West china Hospital, Sichuan University, chengdu 61004., china School of Basic and Forensic Medicine, Sichuan University, chengdu 61004., china) Department of Medical Genetics West China Hospital Division of Human Morbid Genomics Key Laboratory of Biotherapy of Human Diseases of Ministry of Education Sichuan University Chengdu 610041 China Department of Cardiology West China Hospital Sichuan University Chengdu 610041 China School of Basic and Forensic Medicine Sichuan University Chengdu 610041 China

Cholesteryl ester transfer protein (CETP) is a key participant in the reverse transport of cholesterol from the peripheral tissues to the liver. To understand the role that CETP gene plays in the pathogenesis of coronary heart disease (CHD) , the promoter region, all 16 exons and adjacent intronic regions of CETP gene were screened for single nucleotide polymorphisms (SNPs) in 203 CHD patients and 209 controls by a combination of PCR, denaturing high performance liquid chromatography (DHPLC), molecular cloning, and DNA sequencing. A novel missense mutation in the CETP gene was identified. This mutation (L296Q) was a T-to-A conversion at codon 296 of exon 10 which replaced the codon for leucine (CTG) with the codon for glutamine (CAG). Association study revealed that L296Q mutation was associated with CHD with a significantly higher mutant allele frequency in the CHD patients than that in the controls (0. 160 vs. 0.091,x2= 9.014, P = 0.003), and that the odds ratio for the development of CHD was 1.83 for

关键词： cholesteryl ester transfer protein gene (CETP gene) coronary heart disease (CHD) missense mutation plasma lipids single nucleoti.de polymorphism (SNP)