检索结果-南通市图书馆

Origin and age of Mn deposits of the Nantuo Formation in the Sinian System

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1997年第24期42卷 2072-2075页

作者： YANG Jiedong, WANG Zongzhe, XUE Yaosong, SUN Weiguo, TAO Xiancong and ZHOU Chuanming1. center of Modern Analysis, nanjing university, nanjing 2.0093, china 2. nanjing Institute of Geology and Palaeontology, Chinese Academy of sciences, nanjing 210008, china center of Modern Analysis Nanjing University Nanjing China nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

THE tillites in the Nantuo Formation of the Sinian System is considered contemporary with theVaranger ice age. The manganese deposits in the Nantuo Formation are most suitable to iso-topic dating and may record the precious information on paleo-ocean chemistry. However,there have heen different views and disputations about their origin and age for a long time. The Sinian System in the Yangtze region is divided into 3 formations from base to top:the Nantuo Formation, the Doushantuo Formation and the Dengying Formation. The

关键词： Neoproterozoie ice age Mn deposit isotopic age.

A mutation in signal peptide of rat resistin gene inhibits differentiation of 3T3-L1 preadipocytes

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第12期25卷 139-145页

作者： Xi-rong GUO2,3, Hai-xia GONG2, Yan-qin GAO4, Li FEI, Yu-hui NI, Rong-hua CHEN Department of Pediatrics, center of Human Functional Genomics, nanjing Medical university, nanjing 210029, china 4Department of Pediatrics, the Third Affiliated Hospital of nanjing Medical university, Yizheng 211900, china Department of Pediatrics Center of Human Functional Genomics Nanjing Medical University Department of Pediatrics the Third Affiliated Hospital of Nanjing Medical University

AIM: To detect the resistin expression of white adipose tissue in diet-induced obese (DIO) versus diet-resistant (DR)rats, andto investigatethe relationshipof mutatedresistin and 3T3-L1 preadipocytes differentiation. METHODS: RT-PCR and Western Blot were used to detect gene /protein expression. 3T3-L1 cells were cultured, transfected, and induced to differentiation using 0.5 mmol/L 3-isobutyl-1-methyxanthine (MIX), 1 mg/L insulin, and 1 μmol/L dexamethasone. Oil red O staining was applied to detect the degree of preadipocytes differentiation. RESULTS: Expression of resistin mRNA was upregulated in DIO rats and downregulated in DR rats. However, the expression levels varied greatly within the groups. Sequencing of the resistin genes from DIO and DR rats revealed a Leu9Val (C25G) missense mutation within the signal peptide in one DR rat. The mutant resistin inhibited preadipocyte differentiation. Local experiments and Western blotting with tagged resistin fusion proteins identified both mutant and wild type proteins in the cytoplasm and secreted into the culture medium. Computer predictions using the Proscan and Subloc programs revealed four putative phosphorylation sites and a possible leucine zipper motif within the rat resistin protein. CONCLUSION: Resistin-increased differentiation may be inhibited by the mutation- containing precursor protein, or by the mutant non-secretory resistin isoform.

关键词： resistin mutation adipocyte differentiation obesity

A new sequential learning algorithm for RBF neural 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(Technological sciences) 2004年第4期47卷 447-460页

作者： YANG Ge1, LV Jianhong1 & LIU Zhiyuan2 1. Department of Power Engineering, Southeast university, nanjing 210096, china 2. Department of Power Engineering, nanjing Institute of Technology, nanjing 210013, china 1. Department of Power Engineering Southeast University 210096 Nanjing China 2. Department of Power Engineering Nanjing Institute of Technology 210013 Nanjing China

Due to their inherent imperfections, it is hard to use the static neural networks for nonlinear time-varying process modeling and prediction, and the minimal resource allocation network (MRAN) is difficult to be realized for its too many regulation parameters. A new sequential learning algorithm for radial basis function (RBF) neural networks based on local projection named Local Projection Network (LPN) is proposed in this paper. The results of validation for several benchmark problems with the new algorithm show that the presented LPN not only has the same level as M-RAN in network size and precision of the outputs, but also has fewer regulation parameters and is more predictable.

关键词： radial basis functions, local projection network, minimal resource allocation network, learning algorithm.

Seasonal variation of global stratosphere-troposphere mass exchange

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12期17卷 1466-1475页

作者： Guo Dong1,2, Lu Daren2 and Sun Zhaobo1(1. Institute of Atmospheric sciences, nanjing university of Information science and Technology, nanjing 210044, china 2. LAGEO, Institute of Atmospheric Physics, Chinese Academy of sciences, Beijing 100029, china) Institute of Atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China LAGEO Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 44 years from 1958 to 2001 using the European center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83% of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.

关键词： stratosphere troposphere mass exchange seasonal variation.

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

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 Chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3,LI Aimin1,3,CAI Jianguo1,3,MENG Guanhua1,3 & ZHANG Quanxing1,3 1. State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,nanjing university.nanjing 2.0093.china 2. nanjing College of Chemical Technology,nanjing 210048,china 3. Jiangsu Engineering & Technology Research center for Organic Toxicant Control and Resource Reuse,nanjing 210038,china 1. State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China 2. nanjing College of Chemical Technology Nanjing 210048 China 3. Jiangsu Engineering & Technology Research center for Organic Toxicant Control and Resource Reuse Nanjing 210038 China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.

Chaotic laser synchronization and its application in optical fiber secure communication

在线全文

学校读者我要写书评

暂无评论

science in china(Series F) 2004年第3期47卷 332-347页

作者： YAN Senlin CHI Zeying CHEN Wenjian Schoof of Electronic Engineering and Photoelectronic Technology, nanjing university of science and Technology, nanjing 210094, china 1. School of Electronic Engineering and Photoelectronic Technology Nanjing University of Science and Technology 210094 Nanjing China

In this paper, optical fiber chaotic secure communication is proposed bycoupling chaotic laser synchronous system with optical fiber propagation channel.Feedback synchronous system of chaotic semiconductor lasers is presented andsynchronous error and decoding formulae are demonstrated. Synchronization betweentwo chaotic laser systems with distributed feedback semiconductor lasers at wavelengthof 1.31 μm is simulatively achieved with almost zero synchronous error. Parametermismatch, synchronous transient response and noise effect on the system are studied.Robustness of synchronization and anti-perturbation can increase by increasing thefeedback coefficient of the system. Influence of group-velocity-dispersion and self-phasemodulation of optical fiber on chaotic laser signal and synchronization are analyzed, and itis found that group-velocity-dispersion affects pulse shape, synchronization and decoding,and limits optical fiber propagation distances, and self-phase modulation does not affectpulse shape, while its product of nonlinear phase shift can affect synchronization anddecoding, and restrict propagation distances of optical fiber chaotic communicationsystem and hence the maximum optical power formula is educed. Injecting parametermodulation and amplitude modulation are numerically simulated in long-haul optical fibersecure communication systems.

关键词： optical fiber chaos synchronization seeure communication

Detection of subcritical crack propagation for concrete dams

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2009年第12期52卷 3654-3660页

作者： BAO TengFei1 ,2&YU Hong 1,2 1College of Water Conservancy&Hydropower Engineering,Hohai university.nanjing 210098,china 2National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety,nanjing 210098,china College of Water Conservancy & Hydropower Engineering Hohai University Nanjing 210098 China National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety Nanjing 210098 China

Subcritical propagation of cracks is a warning sign of *** such propagation is detected at an early stage,timely maintenance measures can be taken to prevent the failure of *** detect the subcritical propagation of a crack,the crack needs to be monitored continuously in a long term, which is not realistic under certain ***,cracks in concrete dams can be monitored continuously by dam monitoring to offer possible detection for subcritical *** this paper, with measured crack openings from dam monitoring,a state equation for characterizing crack development is established based on the grey system *** relation between the stability of the equation and the subcritical crack propagation is investigated,then a criterion is proposed for detecting subcritical *** example demonstrates the validity of the criterion and its potential for practical application.

关键词： crack subcritical propagation criterion concrete

Characteristics of fMRI BOLD signal and its neurophysiological mechanism

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6期17卷 630-638页

作者： Zhao Xiaohu1,2, Wu Yigen3 and Guo Shengli3(1. College of Life sciences, Zhejiang university, Hangzhou 310058, china 2. Imaging Department of Tongji Hospital of Tongji university, Shanghai 200065, china 3. College of Mathematics and Physics, nanjing university of Information science and Technology, nanjing 210044, china) College of Life sciences Zhejiang University Hangzhou 310058 China Imaging Department Tongji Hospital Tongji University Shanghai 200065 China College of Mathematics and Physics Nanjing University of Information Science and Technology Nanjing 210044 China

The functional magnetic resonance imaging (fMRI) based on blood oxygen level dependent (BOLD) contrast has emerged as one of the most potent noninvasive tools for mapping brain function and has been widely used to explore physiological, pathological changes and mental activity in the brain. Exploring the nature and property of BOLD signal has recently attracted more attentions. Despite that great progress has been made in investigation of the characteristics and neurophysiological basis, the exact nature of BOLD signal remains unclear. In this paper we discuss the characteristics of BOLD signals, the nonlinear BOLD response to external stimuli and the relation between BOLD signals and neural electrophysiological recordings. Furthermore, we develop our new opinions regarding nonlinear BOLD response and make some perspectives on future study.

关键词： functional magnetic resonance imaging blood oxygen level dependent nonlinear response neural electrophysiological activity.

P2P traffic optimization

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7期55卷 1475-1492页

作者： ZHANG GuoQiang 1,2 ,TANG MingDong 3 ,CHENG SuQi 2,4 ,ZHANG GuoQing 2 ,SONG HaiBin 5 ,CAO JiGuang 6 & YANG Jing 7 1 School of Computer science and Technology,nanjing Normal university.nanjing 210046,china 2 Institute of Computing Technology,Chinese Academy of sciences,Beijing 100190,china 3 School of Computer science and Engineering,Hunan university of science and Technology,Xiangtan 411201,china 4 Graduate university of Chinese Academy of sciences,Beijing 100190,china 5 nanjing R&D center,Huawei Technologies,nanjing 210012,china 6 china Academy of Telecommunication Research of MIIT,Beijing 100191,china 7 china Mobile Research Institute,Beijing 100053,china 1. School of Computer science and Technology Nanjing Normal University Nanjing 210046 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China3. School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China4. Graduate University of Chinese Academy of Sciences Beijing 100190 China5. Nanjing R&D Center Huawei Technologies Nanjing 210012 China6. China Academy of Telecommunication Research of MIIT Beijing 100191 China7. China Mobile Research Institute Beijing 100053 China

Peer-to-peer (P2P) based content distribution systems have emerged as the main form for content distribution on the Internet,which can greatly reduce the distribution cost of content providers and improve the overall system ***,the mismatch between the overlay and underlay networks causes large volume of redundant traffic,which intensifies the tension between P2P content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2P *** paper surveys the state-of-art P2P traffic optimization technologies from three perspectives:P2P cache,locality-awareness and data *** details,comparison between these technologies and their applicabilities are presented,followed by a discussion of the issues that remain to be addressed and the direction of future content distribution research.

关键词： P2P traffic localization P2P traffic optimization P2P cache locality-awareness network coding content-centric network