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Reconstruction of precipitation variation from tree rings in recent 1.00 years in Delingha, Qinghai

Science china Earth Sciences 2005年第7期48卷 939-949页

作者： SHAO Xuemei1. HUANG Lei1. LIU Hongbin2, LIANG Eryuan1. FANG Xiuqi3 & WANG Lili1.1. Institute of Geographic Sciences and Natural Resources research, Chinese Academy of Sciences, {1. 1.01.1. china 2. National Climate center, {1. 1.0081. china 3. {1. Normal University, {1. 1.0875, china Institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing 100101 China National Climate center Beijing 100081 China beijing Normal University Beijing 100875 China

Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1.00 years was re- constructed for Delingha. The reconstruction can capture 63.1. of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD1.20—1.33 and 1.33—2001. whereas dry intervals in 1.29—1.1. and 1.34—1.41. In ad- dition, the magnitude in precipitation variation was lower before 1.30 with about 1. mm, but it increased to 30 mm during the period of 1.30 to 1.50. After 1.50, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1.90s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1.00-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 21.t century.

关键词： northeastern part of the Qaidam Basin tree-ring width series of Qilian juniper precipitation reconstruction in 1.00 years.

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Explanation of the mechanism of carcinogenesis and syntheses of anticancer agents with high selectivity

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Science china Chemistry 2006年第1期49卷 44-62页

作者： DAI Qianhuan1.2 1. center of Chemistry and Bioengineering of Cancer {1., beijing Polytechnic University (Now known as beijing Univer-sity of Technology), beijing 1.0022, china 2. center of Environmental Sciences, Peking University, beijing 1.0871. china 1. center of Chemistry and Bioengineering of Cancer {1. Beijing Polytechnic University Beijing 100022 China 2. center of Environmental Sciences Peking University Beijing 100871 China

In 1.79, the mechanism of chemical carcinogenesis, a challenging anddifficult scientific problem pending for a number of years, was explained by Dai Qianhuan. Themechanism named di-region theory predicted that a carcinogen always metabolizes to form a specialbi-functional alky-lating agent. This agent induces cross-linkages between the complementary basepairs in DMA and switches on initial mutageneses in genomes including point and frameshiftmutations. This, in turn, induces further deep mutageneses including the production of variouschimeric chromosomes, deletions and other aberrations found in genomes. In the end this initiatescarcinogenesis of the whole cell through the reverse transcription mechanism after a lengthyincubation period. Recently, this laboratory has verified that physical carcinogenesis, includingthe oncogenesis induced by radiation and asbestos as well as the carcinogenesis induced byendogenous factors such as estrogen or diethyl-stilbestrol switch on carcinogenesis by inducing theformation of cross-linkages between the complementary base pairs in DNA. Di-region theory has nowbeen supported by many experimental observations such as mutational spectra of various *** potential for carcinogenesis, teratogenesis, sterility and mutagenesis lumped together asgenetic toxicity appears to originate almost uniformly from the cross-linking between complementarybases, i.e. malignant cross-linking, which is in accordance with di-region theory. Other forms ofcross-linking between non-complementary bases, benign cross-linkings, show bi-functional alkylationanticancer activity but lack genetic toxicity. The predictable design and synthesis of a highselectivity anticancer agent with high efficacy and low genetic toxicity, a goal long pursued incancer chemotherapy, have been realized for the first time in this laboratory by inhibitingmalignant and heightening benign cross-linking using the principles of di-region theory. A series ofpatented new anticanc

关键词： mechanism of carcinogenesis, di-region theory, minoplatin, selectivity of anticancer agent, cross-linking between DNA bases, anticancer platinum complexes, predictive design of anticancer agent, second generation anticancer agent.

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Application of Multicast-based Video Conference on CERNET Backbone

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计算机工程 2002年第S1期28卷 133-136页

作者： ZHANG Xuan, WANG Yalei, LI Chongrong(network {1. center of tsinghua University, beijing 1.0084,china) network {1. center of tsinghua University Beijing 100084China

Multicast-based video conference is a representative application in advanced network. In multi-point video conference using multicast can get better efficiency facilitated by inner-group broadcast mechanism. In the application, the multicast-based network resources assignment, management and security should be considered together. This paper presents a framework model of multicast-based video conferencing application with three layers. And a practical multicast-based video conferencing is implemented in CERNET(china Education and research network) backbone. The practice is valuable for the development of multicast-based video conferencing application in china.

关键词： Multicast Video conference network application

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Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1.,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

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Study on attribute characterization for reservoir dynamic monitoring by seismic

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Science china Earth Sciences 2008年第S2期51卷 218-225页

作者： CHEN XiaoHong1.3,LI JingYe2,3 & ZHAO Wei4 1.Key Lab of Geophysical Exploration of CNPC,china Petroleum University,{1. 1.2249,china 2 Basin & Reservoir research center,china Petroleum University,{1. 1.2249,china 3 State Key Laboratory of Petroleum Resource and Prospecting,china University of Petroleum,{1. 1.2249,china 4 research center of CNOOC,{1. 1.0027,china 1. Key Lab of Geophysical Exploration of CNPC China Petroleum University Beijing 102249 China 3. State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China 2. Basin & Reservoir research {1. China Petroleum University Beijing 102249 China 4. research {1. of CNOOC Beijing 100027 China

Study on characterizing reservoir parameters dynamic variations by time-lapse seismic attributes is the theoretical basis for effectively distinguishing reservoir parameters variations and conducting time-lapse seismic interpretation,and it is also a key step for time-lapse seismic application in real oil fields. Based on the rock physical model of unconsolidated sandstone,the different effects of oil saturation and effective pressure variations on seismic P-wave and S-wave velocities are calculated and analyzed. Using numerical simulation on decoupled wave equations,the responses of seismic amplitude with different offsets to reservoir oil saturation variations are analyzed,pre-stack time-lapse seismic attributes differences for oil saturation and effective pressure variations of P-P wave and P-S converted wave are calculated,and time-lapse seismic AVO (Amplitude Versus Offset) response rules of P-P wave and P-S converted wave to effective pressure and oil saturation variations are compared. The theoretical modeling study shows that it is feasible to distinguish different reservoir parameters dynamic variations by pre-stack time-lapse seismic information,including pre-stack time-lapse seismic attributes and AVO information,which has great potential in improving time-lapse seismic interpreta-tion precision. It also shows that the time-lapse seismic response mechanism study on objective oil fields is especially important in establishing effective time-lapse seismic data process and interpreta-tion scheme.

关键词： time-lapse seismic dynamic monitoring rock physical model pre-stack attribute Amplitude Versus Offset (AVO)

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Effects of binders on the performance of electric double-layer capacitors of carbon nanotube electrodes

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Progress in Natural Science:Materials International 2005年第5期15卷 453-457页

作者： LI Chensha1.*, WANG Dazhi1. ZHANG Baoyou2, WANG Xiaofeng1. CAO Maosheng3 and LIANG Ji1.1. Department of Mechanical Engineering, tsinghua University, {1., china 2. center for Analysis and Measurement, Harbin Institute of Technology, Harbin 1.0001. china 3. School of Material Science and Engineering, tsinghua University, {1., china) Department of Mechanical Engineering Tsinghua University Beijing 100084 China center for Analysis and Measurement Harbin Institute of Technology Harbin 150001 China School of Material Science and Engineering Tsinghua University Beijing 100084 China

Polarizable electrodes of electric double layer capacitor (EDLCs) were made from carbon nanotubes. Effects of different binders, which are phenolic resin (PF) and polytetrafluoroethylene (PTFE), on the properties of polarizable electrodes are studied. Results indicate that the microstructure, pore size distribution and specific capacitance of the electrodes with PTFE binder are superior to those electrodes with PF binder after carbonization. The suitable binder (PTFE) for carbon nanotubes electrodes is proposed.

关键词： carbon nanotubes electric double-layer capacitors phenolic resin polytetrafluoroethylene.

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research on the multi-level intake water temperature effect of the Yalong River Jinping-I hydropower project

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Science china(Technological Sciences) 2011年第S1期54卷 125-132页

作者： WU ShiYong 1.CAO Wei 1.WANG HongMei 1.SUN ShuangKe 2 &CHEN QiuWen 3 1.Ertan Hydropower Development Company,Ltd.,Chengdu 61.051.china 2 china Institute of Water Resources and Hydropower research,beijing 1.0038,china 3 research center for Eco-Environmental Sciences,Chinese Academy of Sciences,beijing 1.0085,china 1. Ertan Hydropower Development Company Ltd. Chengdu 610051 China2. China Institute of Water Resources and Hydropower Research Beijing 100038 China3. Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Based on the discussion of the multi-level intake application status of high dam reservoir,this paper takes the Jinping-I hydropower project reservoir in the Yalong River as an example,which is shaped by the highest 305 m high arch dam,and carries out the forecasting research on the reservoir temperature by numerical simulation and physical model *** paper studies the intake effect of withdrawing the surface warm water by the stoplog gates inlets and verifies the reliability of the mathematical model by comparative *** results show that for a high dam hydropower station,taking the appropriate multi-level intake measure can withdraw the surface warm water in the spawning season and provide a favorable environment for the fish *** technical ideas and implementation scheme are adopted in this *** can provide technical reference for the solutions of similar problems in the future and it also has important engineering significance on the research of water temperature in large deep reservoirs.

关键词： water temperature multi-level intake Jinping-I hydropower project

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A Novel network Management Model Based on XML for Service and Resource

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计算机工程 2002年第S1期28卷 77-81页

作者： ZHANG JinxiangWU JianpingWANG Jilong(network {1. center of tsinghua University, beijing 1.0084,china, jxzhang@***) network {1. center of tsinghua University Beijing 100084China j xzhang ***

XML can allow for the interchange of data between management applications using different information models. Furthermore, CORBA technique is increasingly used in the management of service and resource in the heterogeneous network environment. As the scheme of information arrangement of CORBA is flat file style, which handles querying, deleting, and insertinginformation inefficiently, this paper puts forward a novel network management model based on XML in the domain of the management of CERNET (china Education and research network), which has used a tree structure of managed objects arrangement to provide efficient operation on managed objects. In addition, arrangement, definition, implementation and finding schemes for CORBA managed objects using XML are also given by the tree structure, and thus can arrange and retrieve managed objects efficiently.

关键词： XMLCORBAnetwork managementModel

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2.5-dimensional angle potential field algorithm for the real-time autonomous navigation of outdoor mobile robots

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Science china(Information Sciences) 2011年第10期54卷 2100-2112页

作者： QIU Quan 1.3 & HAN JianDa 2 1.beijing {1. center of Intelligent Equipment for Agriculture,beijing 1.0097,china 2 State Key Laboratory of Robotics,Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 1.001.,china 3 National {1. center for Intelligent Agricultural Equipment,beijing 1.0097,china 1. beijing {1. center of Intelligent Equipment for Agriculture Beijing 100097 China3. National Research Center for Intelligent Agricultural Equipment Beijing 100097 China2. State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang 110016 China

A new real-time algorithm for the autonomous navigation of mobile robots equipped with laser scanners is proposed in this *** from the existing algorithms designed for 2-dimensional navigation problems,the new algorithm introduces the height information of the obstacles into the guidance process and behaves as a 2.5-dimensional angle potential field algorithm (2.5D-APF) to fulfill the navigation requirements under complex outdoor terrain ***,one laser scan is partitioned into two kinds of function sectors: guidance sector and inspecting ***,the guidance sector and the inspecting sectors are reconstructed to form a virtual guidance scan,where the 2.5D information is taken into ***,the conventional APF is improved to analyze the virtual guidance scan and generate the navigation *** new algorithm is tested on a tracked mobile robot,and the experimental results validate the proposed algorithm.

关键词： robot 2.5-dimensional outdoor real-time autonomous navigation

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Sea surface temperature east of Australia:A predictor of tropical cyclone frequency over the western North Pacific?

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Chinese Science Bulletin 2011年第2期56卷 196-201页

作者： ZHOU BoTao 1.2 & CUI Xuan 3 1.National Climate center,{1. Meteorological Administration,beijing 1.0081.{1. 2 Nansen-Zhu International research center,Institute of Atmospheric Physics,Chinese Academy of Sciences,beijing 1.0029,{1. 3 National Meteorological center,{1. Meteorological Administration,beijing 1.0081.{1. National Climate center China Meteorological Administration Beijing China Nansen-Zhu International research {1. Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China National Meteorological center China Meteorological Administration Beijing China

The relationship between sea surface temperature (SST) east of Australia and tropical cyclone frequency over the western North Pacific (WNPTCF) is analyzed by use of observation *** WNPTCF from June to October is correlated negatively to spring SST east of *** the spring SST is in the positive phase,a cyclonic circulation anomaly in the upper troposphere and an anticyclonic circulation anomaly in the lower troposphere prevail over the western North Pacific from June to October,concurrent with an anomalous atmospheric subsidence and an enlarged vertical zonal wind *** conditions are unfavorable for tropical cyclone genesis,and thus WNPTCF *** negative phase of the spring SST east of Australia leads to more tropical cyclones over the western North *** spring SST east of Australia may give rise to simultaneous change in tropical atmospheric circulation via the teleconnection wave train,and then subsequently affect atmospheric circulation variation over the western North Pacific.

关键词：热带气旋北太平洋澳大利亚西部海面温度热带大气环流预测频率

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