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Sarcopenia and liver transplant: The relevance of too little muscle mass 被引量:2
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作者 Eric R Kallwitz 《World Journal of Gastroenterology》 SCIE CAS 2015年第39期10982-10993,共12页
Loss of muscle mass and function is a common occurrence in both patients with decompensated cirrhosis and those undergoing liver transplantation. Sarcopenia is associated with morbidity and mortality before and after ... Loss of muscle mass and function is a common occurrence in both patients with decompensated cirrhosis and those undergoing liver transplantation. Sarcopenia is associated with morbidity and mortality before and after liver transplantation. The ability of skeletal muscle mass to recover after transplant isquestionable, and long term adverse events associated with persistent sarcopenia have not been well studied. Limited data is available examining mechanisms by which decreased muscle mass might develop. It is not clear which interventions might reduce the prevalence of sarcopenia and associated health burdens. However, measures to either decrease portal hypertension or improve nutrition appear to have benefit. Research on sarcopenia in the liver transplant setting is hampered by differing methodology to quantify muscle mass and varied thresholds determining the presence of sarcopenia. One area highlighted in this review is the heterogeneity used when defining sarcopenia. The health consequences, clinical course and potential pathophysiologic mechanisms of sarcopenia in the setting of cirrhosis and liver transplantation are further discussed. 展开更多
关键词 SARCOPENIA Liver TRANSPLANTATION CIRRHOSIS Body co
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Sleep-disordered breathing and stroke:A relation to be considered
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作者 Ridvan Alimehmeti Arba Cecia +1 位作者 Arsen Seferi Ermir Roci 《World Journal of Clinical Cases》 SCIE 2016年第5期124-126,共3页
Stroke is a leading cause of death and disability.Despite expensive and elaborative research in finding out mechanisms of interrelation between sleep-disordered breathing(SDB)and stroke,there is yet much attention to ... Stroke is a leading cause of death and disability.Despite expensive and elaborative research in finding out mechanisms of interrelation between sleep-disordered breathing(SDB)and stroke,there is yet much attention to be given in stroke units worldwide to the prompt diagnosis and treatment of SDB in order to improve morbidity and mortality rates related with stroke.The preventive diagnosis and treatment of SDB reduce stroke rate and improves penumbra area in case of ischemic stroke.Stroke itself predispose to SDB,making the interrelationship more complicated.The review by Parra O and Arboix A reflects the results from carefully selected reviews reported in the literature so far.This review of the literature and presentation of the original study of the Authors based on their patients’data,enhances the conviction that there exists a direct relation between SDB and stroke.Diagnosis of SDB in new stroke cases should be sought and treated carefully whenever present. 展开更多
关键词 Sleep-disordered STROKE HYPERTENSION PENUMBRA BREATHING
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Speech Acts and the Truth-Conditional Analysis of Temporal Expressions
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作者 Douglas J. Wulf 《Journal of Philosophy Study》 2013年第2期97-112,共16页
Truth-conditional approaches to tense and other temporal expressions have relied on both linear-time and branching-time frameworks as needed. However, in the truth-conditional enterprise generally, it seems advisable ... Truth-conditional approaches to tense and other temporal expressions have relied on both linear-time and branching-time frameworks as needed. However, in the truth-conditional enterprise generally, it seems advisable to settle on a single depiction of time. Linear time is the simpler framework, and branching time faces difficulties for which we seem to have no immediate solutions. This paper defends the applicability of linear time. The apparent branching of time results from the use of speech acts other than factual assertion. Truth in correspondence with specific conditions is relevant when making factual assertions. However, we are in no epistemic position to advance factual assertions about the future, but only suppositions and predictions. For these, the truth-conditional content is employed differently. For suppositions and predictions, we only "pretend" to reference things, to assert facts, and to accept them as "true." There is a wide array of alternatives about what we can suppose or predict, giving the impression of branching options. Suppositions and predictions under active consideration are often marked with present tense, whereas those that are inactive (not presently under active consideration but nonetheless relevant) are often marked with past tense. 展开更多
关键词 English language (modern) SEMANTICS imperfective paradox non-factual before TENSE aspect application of truth-conditional semantics
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TBtools: An Integrative Toolkit Developed for Interactive Analyses of Big Biological Data 被引量:1148
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作者 Chengjie Chen Hao Chen +4 位作者 Yi Zhang Hannah R.Thomas Margaret H.Frank Yehua He Rui Xia 《Molecular Plant》 SCIE CAS CSCD 2020年第8期1194-1202,共9页
The rapid development of high-throughput sequencing techniques has led biology into the big-data era.Data analyses using various bioinformatics tools rely on programming and command-line environments,which are challen... The rapid development of high-throughput sequencing techniques has led biology into the big-data era.Data analyses using various bioinformatics tools rely on programming and command-line environments,which are challenging and time-consuming for most wet-lab biologists.Here,we present TBtools(a Toolkit for Biologists integrating various biological data-handling tools),a stand-alone software with a userfriendly interface.The toolkit incorporates over 130 functions,which are designed to meet the increasing demand for big-data analyses,ranging from bulk sequence processing to interactive data visualization.A wide variety of graphs can be prepared in TBtools using a new plotting engine("JIGplot")developed to maximize their interactive ability;this engine allows quick point-and-click modification of almost every graphic feature.TBtools is platform-independent software that can be run under all operating systems with Java Runtime Environment 1.6 or newer.It is freely available to non-commercial users at https://github.com/CJ-Chen/TBtools/releases. 展开更多
关键词 TBtools BIOINFORMATICS big data data visulization gene family
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Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS 被引量:1084
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作者 LIU YongSheng HU ZhaoChu +4 位作者 ZONG KeQing GAO ChangGui GAO Shan XU Juan CHEN HaiHong 《Chinese Science Bulletin》 SCIE EI CAS 2010年第15期1535-1546,共12页
A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The... A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti). 展开更多
关键词 PB同位素 微量元素 元素分析 ICP MS法 锆石 LA 固体火箭发动机
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Characterization of microRNAs in serum: a novel class of biomarkers for diagnosis of cancer and other diseases 被引量:983
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作者 Xi Chen Yi Ba +26 位作者 Lijia Ma Xing Cai Yuan Yin Kehui Wang Jig ang Guo Yujing Zhang Jiangning Chen Xing Guo Qibin Li Xiaoying Li Wenjing Wang Yan Zhang Jin Wang Xueyuan Jiang Yang Xiang Chen Xu Pingping Zheng Juanbin Zhang Ruiqiang Li Hongjie Zhang Xiaobin Shang Ting Gong Guang Ning Jun Wang Ke Zen Junfeng Zhang Chen-Yu Zhang 《Cell Research》 SCIE CAS CSCD 2008年第10期997-1006,共10页
Dysregulated expression of microRNAs (miRNAs) in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and o... Dysregulated expression of microRNAs (miRNAs) in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and other animals such as mice, rats, bovine fetuses, calves, and horses. The levels of miRNAs in serum are stable, reproducible, and consistent among individuals of the same species. Employing Solexa, we sequenced all serum miRNAs of healthy Chinese subjects and found over 100 and 91 serum miRNAs in male and female subjects, respectively. We also identified specific expression patterns of serum miRNAs for lung cancer, colorectal cancer, and diabetes, providing evidence that serum miRNAs contain fingerprints for various diseases. Two non-small cell lung cancer-specific serum miRNAs obtained by Solexa were further validated in an independent trial of 75 healthy donors and 152 cancer patients, using quantitative reverse transcription polymerase chain reaction assays. Through these analyses, we conclude that serum miRNAs can serve as potential biomarkers for the detection of various cancers and other diseases. 展开更多
关键词 serum-microRNA expression profile FINGERPRINT blood-based biomarker Solexa CANCERS diabetes
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用陆地卫星TM6数据演算地表温度的单窗算法 被引量:828
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作者 覃志豪 Zhang Minghua +1 位作者 Arnon Karnieli Pedro Berliner 《地理学报》 EI CSCD 北大核心 2001年第4期456-466,共11页
陆地卫星 TM数据 (TM6)热波段表示地表热辐射和地表温度变化。长期以来 ,从 TM6数据中演算地表温度通常是通过所谓大气校正法。这一方法需要估计大气热辐射和大气对地表热辐射传导的影响 ,计算过程很复杂 ,误差也较大 ,在实际中应用不... 陆地卫星 TM数据 (TM6)热波段表示地表热辐射和地表温度变化。长期以来 ,从 TM6数据中演算地表温度通常是通过所谓大气校正法。这一方法需要估计大气热辐射和大气对地表热辐射传导的影响 ,计算过程很复杂 ,误差也较大 ,在实际中应用不多。根据地表热辐射传导方程 ,推导出一个简单易行并且精度较高的演算方法 ,把大气和地表的影响直接包括在演算公式中。该算法需要用地表辐射率、大气透射率和大气平均温度 3个参数进行地表温度的演算。验证表明 ,该方法的地表温度演算较高。当参数估计没有误差时 ,该方法的地表温度演算精度达到 <0 .4℃ ,在参数估计有适度误差时 ,演算精度仍达 <1 .1℃。因该方法适用于仅有一个热波段的遥感数据 ,故称为单窗算法。 展开更多
关键词 地表温度 热辐射 LandsatTM单窗算法 亮度温度 陆地卫星
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Current cancer situation in China:good or bad news from the 2018 Global Cancer Statistics? 被引量:871
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作者 Rui-Mei Feng Yi-Nan Zong +1 位作者 Su-Mei Cao Rui-Hua Xu 《Cancer Communications》 SCIE 2019年第1期202-213,共12页
Cancer is the leading cause of death in China and depicting the cancer pattern of China would provide basic knowhows on how to tackle it more effectively.In this study we have reviewed several reports of cancer burden... Cancer is the leading cause of death in China and depicting the cancer pattern of China would provide basic knowhows on how to tackle it more effectively.In this study we have reviewed several reports of cancer burden,including the Global cancer statistics 2018 and Cancer statistics in China,2015,along with the GLOBCAN 2018 online database,to investigate the differences of cancer patterns between China,the United States(USA)and the United Kingdom(UK).An estimated 4.3 million new cancer cases and 2.9 million new cancer deaths occurred in China in 2018.Compared to the USA and UK,China has lower cancer incidence but a 30%and 40%higher cancer mortality than the UK and USA,among which 36.4%of the cancer-related deaths were from the digestive tract cancers(stomach,liver,and esophagus cancer)and have relatively poorer prognoses.In comparison,the digestive cancer deaths only took up≤5%of the total cancer deaths in either USA or UK.Other reasons for the higher mortality in China may be the low rate of early-stage cancers at diagnosis and non-uniformed clinical cancer treatment strategies performed by different regions.China is undergoing the cancer transition stage where the cancer spectrum is changing from developing country to developed country,with a rapidly increase cancer burden of colorectal,prostate,female breast cancers in addition to a high occurrence of infection-related and digestive cancers.The incidence of westernized lifestyle-related cancers in China(i.e.colorectal cancer,prostate,bladder cancer)has risen but the incidence of the digestive cancers has decreased from 2000 to 2011.An estimated 40%of the risk factors can be attributed to environmental and lifestyle factors either in China or other developed countries.Tobacco smoking is the single most important carcinogenic risk factor in China,contributing to~24.5%of cancers in males.Chronic infection is another important preventable cancer contributor which is responsible for~17%of cancers.Comprehensive prevention and control strategies in China should inc 展开更多
关键词 GLOBCAN 2018 Cancer pattern China USA UK Carcinogenic risk factor Tobacco smoking Chronic infection Westernized lifestyles Cancer control strategies
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Evolution of the novel coronavirus from the ongoing Wuhan outbreak and modeling of its spike protein for risk of human transmission 被引量:778
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作者 Xintian Xu Ping Chen +5 位作者 Jingfang Wang Jiannan Feng Hui Zhou Xuan Li Wu Zhong Pei Hao 《Science China(Life Sciences)》 SCIE CAS CSCD 2020年第3期457-460,共4页
Dear Editor,The occurrence of concentrated pneumonia cases in Wuhan city,Hubei province of China was first reported on December 30,2019 by the Wuhan Municipal Health Commission(WHO,2020).The pneumonia cases were found... Dear Editor,The occurrence of concentrated pneumonia cases in Wuhan city,Hubei province of China was first reported on December 30,2019 by the Wuhan Municipal Health Commission(WHO,2020).The pneumonia cases were found to be linked to a large seafood and animal market in Wuhan,and measures for sanitation and disinfection were taken swiftly by the local government agency.The Centers for Disease Control and Prevention(CDC)and Chinese health authorities later determined and announced that a novel coronavirus(CoV),denoted as 2019-nCoV,had caused the pneumonia outbreak in Wuhan city(CDC,2020).Scientists from multiple groups had obtained the virus samples from hospitalized patients(Normile,2020).The isolated viruses were morphologically identical when observed under electron microscopy. 展开更多
关键词 WUHAN EVOLUTION measures
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从智能电网到能源互联网:基本概念与研究框架 被引量:759
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作者 董朝阳 赵俊华 +1 位作者 文福拴 薛禹胜 《电力系统自动化》 EI CSCD 北大核心 2014年第15期1-11,共11页
以化石能源集中式利用为特征的传统经济和社会发展模式正在逐步发生变革,而以新能源技术和互联网技术为代表的第三次工业革命正在兴起。作为第三次工业革命的核心技术,能源互联网力图结合可再生能源技术与互联网技术,推动分布式可再生... 以化石能源集中式利用为特征的传统经济和社会发展模式正在逐步发生变革,而以新能源技术和互联网技术为代表的第三次工业革命正在兴起。作为第三次工业革命的核心技术,能源互联网力图结合可再生能源技术与互联网技术,推动分布式可再生能源的大规模利用与分享,促进电力、交通、天然气等多种复杂网络系统的相互融合,最终实现改变能源利用模式,推动经济与社会可持续发展的目的。在此背景下,展望了能源互联网的发展前景,并试图建立其基本的研究框架。首先,给出了能源互联网的初步定义,并概述了能源互联网的基本架构及其组成。随后,针对广域内分布式设备的协调与控制、电力系统与交通系统的融合、电力系统与天然气网络的融合、信息物理建模及安全等几个核心问题,探讨了能源互联网研究中可能面临的主要挑战。 展开更多
关键词 能源互联网 智能电网 天然气网络 电气化交通 信息物理建模 信息物理安全性
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有效控制“H型”高血压——预防卒中的新思路 被引量:740
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作者 胡大一 徐希平 《中华内科杂志》 CAS CSCD 北大核心 2008年第12期976-977,共2页
人体血中的同型半胱氨酸水平在10μmol/L以上称为高同型半胱氨酸血症或血浆同型半胱氨酸水平升高^[1]。一项6城市研究数据显示,我国成年高血压患者中伴有高同型半胱氨酸血症者约占75%(男性占91%,女性占60%)^[2]。这类伴有高同... 人体血中的同型半胱氨酸水平在10μmol/L以上称为高同型半胱氨酸血症或血浆同型半胱氨酸水平升高^[1]。一项6城市研究数据显示,我国成年高血压患者中伴有高同型半胱氨酸血症者约占75%(男性占91%,女性占60%)^[2]。这类伴有高同型半胱氨酸血症的原发性高血压,我们定义为“H型”高血压。“H型”高血压对我国卒中的预防可能具有特殊意义。 展开更多
关键词 高血压患者 高同型半胱氨酸血症 H型 卒中 预防 血浆同型半胱氨酸 原发性高血压 数据显示
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Petrogenesis of Mesozoic granitoids and volcanic rocks in South China: A response to tectonic evolution 被引量:711
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作者 Xinmin Zhou Tao Sun +2 位作者 Weizhou Shen Liangshu Shu Yaoling Niu 《Episodes》 SCIE 2006年第1期26-33,共8页
This paper summarizes the new results on the petrogenesis of Mesozoic granitoids and volcanic rocks in South China. The authors propose that these rocks were formed in time and space as a response to regional tectonic... This paper summarizes the new results on the petrogenesis of Mesozoic granitoids and volcanic rocks in South China. The authors propose that these rocks were formed in time and space as a response to regional tectonic regime change from the continent-continent collision of the Indosinian orogeny within the broad Tethyan orogenic domain in the Early Mesozoic (T1-T3) (Period Ⅰ) to the largely extensional setting as a result of the Yanshanian orogeny genetically associated with the NW-WNW-ward subduction of the paleo-Pacific oceanic lithosphere in the Late Mesozoic (J2-K2) (Period Ⅱ). Of the Period I Indosinian granitoids, the early (T1-T2^1) ones are syn-collisional, and formed in a compressional setting; the late (T2^2-T3) ones are latecollisional, and formed in a locally extensional environment. During the Period Ⅱ Yanshanian magmatism, the Early Yanshanian (J2-J3) granitoid-volcanic rocks, which are distributed mainly in the Nanling Range and in the interior of the South China tectonic block (SCB), are characteristic of rift-type intraplate magmatism, whereas the Late Yanshanian K1 granitoidovolcanic rocks are interpreted as genetically representing active continental margin magmatism. The K2 tholeiitic basalts interlayered with red beds are interpreted as genetically associated with the development of back-arc extensional basins in the interior of the SCB. The Yanshanian granitoid-volcanic rocks are distributed widely in South China, reflecting extensional tectonics within much of the SCB. The extension-induced deep crustal melting and underplating of mantle-derived basaltic melts are suggested as the two principal driving mechanisms for the Yanshanian granitic magmatism in South China. 展开更多
关键词 SOUTHEASTERN CHINA CRUSTAL EVOLUTION JAPANESE ISLANDS GEOCHEMISTRY MAGMATISM ASIA ND CONSTRAINTS SUBDUCTION ACCRETION
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Science Mapping:A Systematic Review of the Literature 被引量:695
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作者 Chaomei Chen 《Journal of Data and Information Science》 CSCD 2017年第2期1-40,共40页
Purpose: We present a systematic review of the literature concerning major aspects of science mapping to serve two primary purposes: First, to demonstrate the use of a science mapping approach to perform the review ... Purpose: We present a systematic review of the literature concerning major aspects of science mapping to serve two primary purposes: First, to demonstrate the use of a science mapping approach to perform the review so that researchers may apply the procedure to the review of a scientific domain of their own interest, and second, to identify major areas of research activities concerning science mapping, intellectual milestones in the development of key specialties, evolutionary stages of major specialties involved, and the dynamics of transitions from one specialty to another.Design/methodology/approach: We first introduce a theoretical framework of the evolution of a scientific specialty. Then we demonstrate a generic search strategy that can be used to construct a representative dataset of bibliographic records of a domain of research. Next, progressively synthesized co-citation networks are constructed and visualized to aid visual analytic studies of the domain's structural and dynamic patterns and trends. Finally, trajectories of citations made by particular types of authors and articles are presented to illustrate the predictive potential of the analytic approach.Findings: The evolution of the science mapping research involves the development of a number of interrelated specialties. Four major specialties are discussed in detail in terms of four evolutionary stages: conceptualization, tool construction, application, and codification. Underlying connections between major specialties are also explored. The predictive analysis demonstrates citations trajectories of potentially transformative contributions.Research limitations: The systematic review is primarily guided by citation patterns in the dataset retrieved from the literature. The scope of the data is limited by the source of the retrieval, i.e. the Web of Science, and the composite query used. An iterative query refinement is possible if one would like to improve the data quality, although the current approach serves our purpose adequately. 展开更多
关键词 Science mapping Knowledge domain visualization Domain analysis Systematic review Cite Space
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Management of hepatitis B in China 被引量:661
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作者 LU Feng-min ZHUANG Hui 《Chinese Medical Journal》 SCIE CAS CSCD 2009年第1期3-4,共2页
Hepatitis B virus (HBV) infection is a global public health problem. According to the data of WorldHealth Organization (WHO), 2 billion people worldwide have been infected with HBV, and among them 350400 million a... Hepatitis B virus (HBV) infection is a global public health problem. According to the data of WorldHealth Organization (WHO), 2 billion people worldwide have been infected with HBV, and among them 350400 million are chronic HBV carriers. Hepatitis B causes about 1 million deaths of HBV related liver failure, cirrhosis, and hepatocellular carcinoma annually. 展开更多
关键词 HBV 乙肝病毒 乙型肝炎 肝硬变
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快速叶绿素荧光诱导动力学分析在光合作用研究中的应用 被引量:588
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作者 李鹏民 高辉远 Reto J.Strasser 《植物生理与分子生物学学报》 CAS CSCD 北大核心 2005年第6期559-566,共8页
JIP-测定(JIP-test)是以生物膜能量流动为基础建立的分析方法。利用该方法可以获得有关光系统II的大量信息。文章介绍了快速叶绿素荧光诱导动力学曲线的定义、数据分析方法及相关参数的意义,并举例说明如何利用该方法分析不同环境条件... JIP-测定(JIP-test)是以生物膜能量流动为基础建立的分析方法。利用该方法可以获得有关光系统II的大量信息。文章介绍了快速叶绿素荧光诱导动力学曲线的定义、数据分析方法及相关参数的意义,并举例说明如何利用该方法分析不同环境条件对光合机构主要是PSII的供体侧、受体侧及PSII反应中心的影响。 展开更多
关键词 快速叶绿素荧光诱导动力学 光合机构 PSII 原初光化学反应 JIP-测定
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IPCC第五次评估报告第一工作组报告的亮点结论 被引量:558
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作者 秦大河 Thomas Stocker 《气候变化研究进展》 CSCD 北大核心 2014年第1期1-6,共6页
IPCC第h次评估报告(AR5)第一工作组(WGI)报告的亮点结论,是过去7年全世界气候变化科学研究成果凝练出来的精华。20世纪50年代以来全球气候变暖的一半以上是人类活动造成的。1971年以来人为排放温室气体产生热量的93%进入了海洋,... IPCC第h次评估报告(AR5)第一工作组(WGI)报告的亮点结论,是过去7年全世界气候变化科学研究成果凝练出来的精华。20世纪50年代以来全球气候变暖的一半以上是人类活动造成的。1971年以来人为排放温室气体产生热量的93%进入了海洋,海洋还吸收了大约30%人为排放的CO2,导致海表水pH值下降了0.1,等等。采用全球耦合模式比较计划第五阶段(CMIP5)的模式,预估未来全球气候变暖仍将持续,2l世纪宋全球平均地表温度往19862005年的基础上将升高0-3~4.8℃。限制气候变化需要大幅度持续减少温室气体排放。如果将18611880年以来的人为CO:累积排放控制在1000GtC,那么人类有超过66%的可能性把未来升温幅度控制征2℃以内(相对于1861-1880年)。 展开更多
关键词 气候变化 温室气体 IPCCAR5 WGI
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Future Physics Programme of BESⅢ 被引量:538
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作者 M.Ablikim M.N.Achasov +147 位作者 P.Adlarson S.Ahmed M.Albrecht M.Alekseev A.Amoroso F.F.An Q.An Y.Bai O.Bakina R.Baldini Ferroli Y.Ban K.Begzsuren J.V.Bennett N.Berger M.Bertani D.Bettoni F.Bianchi J Biernat J.Bloms I.Boyko R.A.Briere L.Calibbi H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.Chai J.F.Chang W.L.Chang J.Charles G.Chelkov Chen G.Chen H.S.Chen J.C.Chen M.L.Chen S.J.Chen Y.B.Chen H.Y.Cheng W.Cheng G.Cibinetto F.Cossio X.F.Cui H.L.Dai J.P.Dai X.C.Dai A.Dbeyssi D.Dedovich Z.Y.Deng A.Denig Denysenko M.Destefanis S.Descotes-Genon F.De Mori Y.Ding C.Dong J.Dong L.Y.Dong M.Y.Dong Z.L.Dou S.X.Du S.I.Eidelman J.Z.Fan J.Fang S.S.Fang Y.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng M.Fritsch C.D.Fu Y.Fu Q.Gao X.L.Gao Y.Gao Y.Gao Y.G.Gao Z.Gao B.Garillon I.Garzia E.M.Gersabeck A.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl M.Greco L.M.Gu M.H.Gu Y.T.Gu A.Q.Guo F.K.Guo L.B.Guo R.P.Guo Y.P.Guo A.Guskov S.Han X.Q.Hao F.A.Harris K.L.He F.H.Heinsius T.Held Y.K.Heng Y.R.Hou Z.L.Hou H.M.Hu J.F.Hu T.Hu Y.Hu G.S.Huang J.S.Huang X.T.Huang X.Z.Huang Z.L.Huang N.Huesken T.Hussain W.Ikegami Andersson W.Imoehl M.Irshad Q.Ji Q.P.Ji X.B.Ji X.L.Ji H.L.Jiang X.S.Jiang X.Y.Jiang J.B.Jiao Z.Jiao D.P.Jin S.Jin Y.Jin T.Johansson N.Kalantar-Nayestanaki X.S.Kang R.Kappert M.Kavatsyuk B.C.Ke I.K.Keshk T.Khan A.Khoukaz P.Kiese R.Kiuchi R.Kliemt L. 《Chinese Physics C》 SCIE CAS CSCD 2020年第4期I0001-I0004,1-102,共106页
There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac... There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity. 展开更多
关键词 MESON HADRON optimization
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个性化推荐系统的研究进展 被引量:433
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作者 刘建国 周涛 汪秉宏 《自然科学进展》 北大核心 2009年第1期1-15,共15页
互联网技术的迅猛发展把我们带进了信息爆炸的时代.海量信息的同时呈现,一方面使用户很难从中发现自己感兴趣的部分,另一方面也使得大量少人问津的信息成为网络中的"暗信息",无法被一般用户获取.个性化推荐系统通过建立用户... 互联网技术的迅猛发展把我们带进了信息爆炸的时代.海量信息的同时呈现,一方面使用户很难从中发现自己感兴趣的部分,另一方面也使得大量少人问津的信息成为网络中的"暗信息",无法被一般用户获取.个性化推荐系统通过建立用户与信息产品之间的二元关系,利用已有的选择过程或相似性关系挖掘每个用户潜在感兴趣的对象,进而进行个性化推荐,其本质就是信息过滤.个性化推荐系统不仅在社会经济中具有重要的应用价值,而且也是一个非常值得研究的科学问题.事实上,它是目前解决信息过载问题最有效的工具.文中根据推荐算法的不同,分别介绍了协同过滤系统,基于内容的推荐系统,混合推荐系统,以及最近兴起的基于用户—产品二部图网络结构的推荐系统.并结合这些推荐系统的特点以及存在的缺陷,提出了改进的方法和未来可能的若干研究方向.推荐系统的研究受到了信息科学、计算数学、统计物理学、认知科学等多学科的关注,它与管理科学、消费行为等研究也密切相关.能够为不同学科领域的科研工作者研究推荐系统提供借鉴,有助于我国学者了解该领域的主要进展. 展开更多
关键词 推荐系统 个性化推荐 协同过滤 基于内容的推荐 基于网络的推荐
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独立董事能否抑制大股东的“掏空”? 被引量:406
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作者 叶康涛 陆正飞 张志华 《经济研究》 CSSCI 北大核心 2007年第4期101-111,共11页
本文以大股东占用上市公司资金作为研究对象,考察了在中国证券市场上,独立董事的引入能否有效抑制大股东的掏空行为。与以往研究类似,在OLS回归中,我们未能发现独立董事比例与大股东资金占用之间存在显著相关关系。进一步分析表明,中国... 本文以大股东占用上市公司资金作为研究对象,考察了在中国证券市场上,独立董事的引入能否有效抑制大股东的掏空行为。与以往研究类似,在OLS回归中,我们未能发现独立董事比例与大股东资金占用之间存在显著相关关系。进一步分析表明,中国上市公司的独立董事变量具有内生性,在控制独立董事内生性情况下,我们发现独立董事变量与大股东资金占用显著负相关。这表明以往研究未能发现独立董事能够抑制大股东掏空,很可能源于模型设定偏误。在稳健性分析部分,我们采用了多种指标来反映大股东的资金占用行为,本文结论仍然成立。 展开更多
关键词 掏空 独立董事 抑制
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成就动机的测量与分析 被引量:415
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作者 叶仁敏 KuntA.Hagtvet 《心理发展与教育》 CSSCI 北大核心 1992年第2期14-16,共3页
一、问题的提出成就动机是一个比较稳定的个性特征,是一种习得的、与特定情景有关的正向或负向的期望。成就动机的强弱能使人面临的学习任务或工作产生不同的情感反应,从而对其潜在的能力与知识经验的发挥、应用产生不同的作用。成就动... 一、问题的提出成就动机是一个比较稳定的个性特征,是一种习得的、与特定情景有关的正向或负向的期望。成就动机的强弱能使人面临的学习任务或工作产生不同的情感反应,从而对其潜在的能力与知识经验的发挥、应用产生不同的作用。成就动机的测量对于深入了解被试的个性、需要、期望和对事情成败的认识态度,以及可能产生的行为后果;对培养、训练正确的认识和态度,提高学习和工作的效率;在教育中对教师采取适当的教学方法,都有现实意义。 展开更多
关键词 个性特征 教学方法 成就动机 认识态度 中学生 测量与分析 挪威 男女生 得分表 大学生
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