维普中文期刊产品整合服务
1038篇 您的检索式:关键字=Research
    题名 作者 年代 出处 被引量
1中国区域物流业与经济发展协调度研究--基于复合系统模型与30个省区面板数据显示文摘采用复合系统模型计算了全国30个省(区)物流业子系统与经济子系统的有序度,在此基础上得出了全国与东、中、西3个地区各子系统有序度和复合系统协调度,并进一步分析了经济最发达的4个区域的协调度在研究时段内的变化情况。结果显示对物流业子系统贡献最大的序参量是周转量,受各个地方政府2005年加大物流业投入影响,物流业固定资产投资对物流业子系统贡献也明显上升。对经济子系统而言,城镇与农村居民恩格尔系数与人均工资先后对经济子系统贡献最大。总体上,东、中、西3个地区协调度呈上升趋势。张毅 陈圻 2010软科学2010,24,12:68
2Progress of potato staple food research and industry development in China显示文摘Potato is the largest non-cereal food crop worldwide and ranked as the world's fourth most important food crop after rice, wheat, and maize. Potato is a vital food-security crop and substitute for cereal crop considering its high yield and great nutritive value. Therefore, by replacing wheat, rice or maize in traditional staple foods partly by potato, the nutritional value of traditional foods and the utilization of potato are expected to be improved. China is the largest potato producer worldwide in terms of either volume or area. However, majority of potatoes are consumed as fresh vegetables for cuisine, and the industrial processing rate is much lower than the global average. Thus, research and development for nutritional potato stable food suitable for the dietary habits of Chinese residents are of great significance. However, we still confronted plenty of constraints in the development of potato staple food. In order to develop potato staple food suitable for Chinese residents' dietary habit like noodles, Mantou(steamed bread), rice and rice noodles, also to industrialize production of potato staple foods, some transformations need to be realized. Independent innovation is the only choice to realize the potato staple food processing and industrial development strategy on the technical level. Thus a lot of researches have been done to promote the development of potato staple food in China. Up to now, we already developed a series kinds of potato staple foods and some of these staple foods have already been widely promoted in Chinese markets.ZHANG Hong XU Fen WU Yu HU Hong-hai DAI Xiao-feng 2017Journal of Integrative Agriculture2017,16,12:42
3Recent progresses in mangrove conservation,restoration and research in China显示文摘Aims In this paper,we highlighted some key progresses in mangrove conservation,restoration and research in China during last two decades.Methods Based on intensive literature review,we compared the distribution and areas of existing mangroves among selected provinces of China,discussed the issues associated with mangrove conservation and restoration and highlighted major progresses on mangrove research conducted by key institutions or universities in China's Mainland,Hong Kong,Taiwan and Macao.Important findings The population boom and rapid economic developments have greatly reduced mangrove areas in China since 1980s,leaving only 22700 ha mangroves in China's Mainland in 2001.Chinese government has launched a series of programs to protect mangroves since 1980s and has established mangrove ecosystems as high-priority areas for improving environmental and living resource management.During last three decades,a total of 34 natural mangrove conservation areas have been established,which accounts for 80%of the total existing mangroves areas in China.Mangrove restoration areas in China' Mainland accounted for<7%of the total mangroves areas in 2002.A great deal of research papers on Chinese mangroves has been published in international journals.However,more systematic protection strategies and active restoration measurements are still urgently needed in order to preserve these valuable resources in China.Luzhen Chen Wenqing Wang Yihui Zhang Guanghui Lin 2009Journal of Plant Ecology2009,2,2:42
4藏北羌塘中部绒玛地区蓝片岩岩石学、矿物学和^(40)Ar/^(39)Ar年代学显示文摘藏北羌塘中部沿龙木错-双湖-线出露一条低温高压变质带,目前已有多处蓝片岩的报道。然而,除冈玛错地区产有典型的蓝闪石外,多数地区并没有典型蓝闪石的报道。绒玛蓝片岩位于羌塘中部高压变质带的中段,是该带中规模最大、保存最好的蓝片岩,对蓝片岩进行了详细的岩石学和矿物学研究,钠质角闪石主要为蓝闪石、青铝闪石、钠闪石和镁钠闪石。对蓝片岩中蓝闪石和多硅白云母进行了^(40)Ar/^(39)Ar定年,获得了227.3±3.8Ma和215±1.5Ma的坪年龄,分别代表蓝片岩快速俯冲消减和俯冲作用结束开始折返抬升的时代。绒玛蓝片岩岩石学、矿物学和^(40)Ar/^(39)Ar年代学研究为羌塘中部高压变质带的研究提供了新的资料。翟庆国 李才 王军 陈文 张彦 2009岩石学报2009,25,9:38
5Challenges in Research and Development of Traditional Chinese Medicines显示文摘This review is briefly to recall the history of research and development (R&D) of Chinese materia medica (CMM) and to discuss the challenges of Chinese traditional and herbal medicines (CTHM) facing the modern science and technology. The R&D of CTHM is thought to be an important pathway for new drug discovery. Since1949, about 140 approved new drugs have been developed, among which about 80 originated directly or indirectly from medicinal plants. CTHM has gained interest from the international medical, biomedical, and pharmaceutical institutions as a valuable source of potential medicines. For the modernization of CMM and innovative research of CTHM, there are following challenges to be faced: (1) to evaluate the efficacy, pharmacological properties, action mechanism, and active chemical constituents; (2) to develop new methodologies for the quality and safety of CTHM; (3) to apply new '-omics' techniques to accelerate drug discoveries developed from CTHM; and (4) to apply international practices including good agricultural practice, good manufacturing practice, good laboratory practice, and good clinical practice in the R&D of CTHM.LIU Chang-xiao1*, XIAO Pei-gen2, PENG Yong2, SONG Nai-ning1 1. Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China 2. Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Beijing 100193, China 2009Chinese Herbal Medicines2009,1,1:34
6国际化视角--Cell Research办刊经验点滴显示文摘Cell Research自创刊起始终坚持国际化办刊理念和视角,发展到现在已具有较好的国际化基础,具有一定的国际影响,已被国际同行认可。本文从国际合作和引进高端编辑人才两方面介绍了Cell Research人近年来办刊的重要举措,希望能对期刊出版同行和各级领导指导创办我国的国际性期刊有所借鉴。程磊 张爱兰 李党生 2010中国科技期刊研究2010,21,5:31
7用学术影响力评价学术论文——兼论关于学术传承效应和长期引用的两个新指标显示文摘1引言 学术论文是科学技术研究,特别是自然科学基础研究成果的重要表现形式,对其学术影响力的研究一直被科技界所关注.研究学术影响力的一个重要方面是后续学术论文与之前发表的学术论文具有什么关系,这种研究对于学术创新具有重大意义.尚海茹 冯长根 孙良 2016科学通报2016,61,26:31
81901~2013年GPCC和CRU降水资料在中国大陆的适用性评估显示文摘利用1901~2013年中国大陆地区的气象台站实测降水资料,对东英吉利(East Anglia)大学气候研究中心(Climatic Research Unit,CRU)和全球降水气候中心(Global Precipitation Climatology Centre,GPCC)的降水资料分别从季节、年际和年代际尺度上进行了评估。结果表明:1961~2013年CRU与GPCC降水资料均能较准确地描述中国大陆地区的降水特征,且在东部较西部地区、夏季较冬季与站点实测降水情况更为一致。将中国大陆划分为不同区域并在其季节、年际和年代际时间尺度上通过比较降水偏差绝对值的百分比、均方根误差和相关系数等统计量后发现:CRU在青藏高原和其它较大的山脉附近与站点实测降水的差别较大,且年均降水趋势在西北一带的阿尔金山脉、黄土高原、东南地区和长江下游地区,比实测降水的年均趋势小、甚至出现趋势相反的情况。此外,CRU降水的年代际变化趋势也偏小。而GPCC数据不论是降水量还是降水趋势都更接近实际情况。在1901~1961年,通过与65个长期气象观测站点的降水时间序列比较发现,CRU在110°E以西地区与站点观测的降水资料间的差别较大,而GPCC与站点观测资料的吻合较好。最后,利用1961~2013年两套降水资料和站点实测资料分别计算了标准化降水指数(SPI),简单分析了中国大陆地区的干旱变化,发现GPCC对旱涝的时空变化特征的描述比CRU更接近站点实际观测;并且CRU也没有反映出1997年夏季中国地区出现的严重干旱情况,而GPCC较为准确地反映出了这一干旱事件特征。因此,本文的研究结果认为,就中国大陆地区长时期降水资料而言,GPCC的适用性优于CRU。王丹 王爱慧 2017气候与环境研究2017,22,4:34
9Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China显示文摘Bemisia tabaci(Gennadius) biotype B,called a 'superbug',is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity,evolution and molecular eco-adaptation of biotype B.Furthermore,it provides a base for sustainable management of B.tabaci using biological and ecological measures.WAN FangHao1,ZHANG GuiFen1,LIU ShuSheng2,LUO Chen3,CHU Dong4,ZHANG YouJun4,ZANG LianSheng2,JIU Min2,Lü ZhiChuang1,CUI XuHong1,ZHANG LiPing4,ZHANG Fan3,ZHANG QingWen5,LIU WanXue1,LIANG Pei5,LEI ZhongRen1 & ZHANG YongJun1 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Acadeny of Agriculture Sciences,Beijing 100094,China 2 Institute of Applied Entomology,Zhejiang University,Hangzhou 310029,China 3 Institute of Plant and Environment Protection,Beijing Academy of Agricultural and Forestry Sciences,Beijing 100089,China 4 Institute of Vegetables and Flowers,Chinese Acadeny of Agricullare Sciences,Beijing 100081,China 5 Department of Entomology,China Agriculture University,Beijing 100094,China 2009Science China(Life Sciences)2009,52,1:30
10旅游学学科树构建及旅游学研究的时空特征分析——《旅游研究纪事》30年显示文摘本文对国际旅游学界权威学术刊物《旅游研究纪事》(AnnalsofTourismResearch)在1973~2003年间的《主题词索引》(SubjectIndex)进行了统计研究,以此为依据绘制了旅游学学科树,并在此基础上分析了旅游学及其分支学科从1973年至今30多年来研究的时空特征。吴必虎 邢珏珏 2005旅游学刊2005,20,4:29
11Metabolomics and its application in the treatment of coronary heart disease with traditional Chinese medicine显示文摘Traditional Chinese Medicine(TCM) is the treasure of Chinese Nation and gained the gradual acceptance of the international community. However, the methods and theories of TCM understanding of diseases are lack of appropriate modern scientific characterization systems. Moreover, traditional risk factors cannot promote to detection and prevent those patients with coronary artery disease(CAD) who have not developed acute myocardial infarction(MI) in time. To sum up, there is still no objective systematic evaluation system for the therapeutic mechanism of TCM in the prevention and cure of cardiovascular disease.Thus, new ideas and technologies are needed. The development of omics technology, especially metabolomics, can be used to predict the level of metabolites in vivo and diagnose the physiological state of the body in time to guide the corresponding intervention.In particular, metabolomics is also a very powerful tool to promote the modernization of TCM and the development of TCM in personalized medicine. This article summarized the application of metabolomics in the early diagnosis, the discovery of biomarkers and the treatment of TCM in CAD.WU Gao-Song LI Hou-Kai ZHANG Wei-Dong 2019Chinese Journal of Natural Medicines2019,17,5:28
12Tri-Co Robot: a Chinese robotic research initiative for enhanced robot interaction capabilities显示文摘Since the invention of the first industrial robot in 1959, the missions of robots have evolved from basic mechanical transfer or assistance to a diverse range of tasks through close interactions with environment, their human counterparts and robot peers. Through adaptation to uncertain and dynamic environments.Han Ding Xuejun Yang Nanning Zheng Ming Li Yinan Lai Hao Wu 2018National Science Review2018,5,6:24
13NEW METHOD OF SIMULATING CONCENTRATED DRAIN HOLES IN SEEPAGE CONTROL ANALYSIS显示文摘In this paper, based upon the basic solution of sink, the approximate solution of single drain hole in finite elements is derived by use of the superposition principle. Then, the theoretical solution is extended to the case of some drain holes in one finite element, and the method is used in seepage control analysis with quick convergence and high accuracy. On the other hand, if the positions of the drain holes are changed, only some control factors of drain holes are changed, but the finite element grid need not to be reformed. Therefore, the method is more suitable in optimal research of seepage control.Zhan Mei li, Su Bao yu , Liu Jun yong, Shen Zhen zhong College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, P.R.China (Received Aug.1, 1998) 1999Journal of Hydrodynamics1999,11,3:22
14褐煤的超细粉再燃中NO_x的生成与还原的数值模拟显示文摘对CRF(Combustion Research Facility)炉中褐煤的1种常规燃烧和6种超细粉再燃工况进行了数值模拟,模拟所得工况2和工况3的NOx含量分布与中试试验数据较好地吻合.计算结果显示褐煤的超细粉再燃在很大程度上减少了NOx的出口排放,与常规燃烧相比脱除率达到了58.20%~75.06%.同时也对超细粉再燃的再燃区和燃尽区中NOx的生成与还原进行了分析,炉膛出口NOx的含量不仅决定于再燃区NOx的还原率,还决定于燃尽区NOx的新生成.郭永红 孙保民 刘彤 冯兆兴 王旸 李振中 2005中国电机工程学报2005,25,9:23
15复合酶法提取南瓜多糖及其抗氧化性的研究(摘要)(英文)显示文摘[目的]优化复合酶法提取南瓜多糖的工艺条件,研究南瓜多糖的抗氧化性。[方法]采用单因素试验设计研究了不同提取时间、温度、料液比、pH对南瓜多糖提取率的影响,并通过正交试验确定了提取南瓜多糖的最佳的复合酶配比和最佳提取条件。采用水杨酸法检测南瓜多糖对羟基自由基(.OH)和改进的邻苯酚自氧化法检测其对超氧阴离子自由基(O2-)的清除效果。[结果]当纤维素酶的浓度为1.0%、果胶酶为1.5%、木瓜蛋白酶为1.0%时,以及温度为40℃、pH=4.6、料液比为1∶30、提取时间为30min的条件下南瓜多糖的提取率最高;南瓜多糖对.OH具有较好的清除效果,对O2-有部分清除作用。[结论]该研究为南瓜多糖的研究及应用提供了基础资料。孙婕 尹国友 陈兰英 Guo-you Lan-ying 2010Agricultural Science & Technology2010,11,5:20
16城市化对2008年8月25日上海一次特大暴雨的影响显示文摘本文利用新一代中尺度数值天气模式Weather Research and Forecasting Model(v3.1.1,WRFV3)、日本气象厅20 km分析资料及自动站观测数据等模拟了2008年8月25日上海一次特大暴雨过程,并研究了城市化对这次暴雨过程的影响.研究结果表明:WRFV3模式能够较好地模拟出上海0825暴雨的主要分布特征,强降水中心以及暴雨随时间变化趋势;上海城市化使得这次暴雨过程在城市中心区域和迎风区降雨增强,城市背风区降雨减少;而城市化引起的陆面粗糙度等变化的动力作用对城市地区低层风场产生阻挡,使得城市迎风区垂直上升运动增强、水汽增多,是造成城市迎风区降雨增强的主要原因.吴风波 汤剑平 2011南京大学学报(自然科学版)2011,47,1:20
17A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems显示文摘Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years(2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem,trends, and challenges are described from three aspects. Conclusions of the paper are presented,and the future of SRURSs is discussed to enable further research interests.Xilun DING Pin GUO Kun XU Yushu YU 2019Chinese Journal of Aeronautics2019,32,1:18
18基于TAM的百度百科用户参与意向的影响因素研究显示文摘基于TAM的模型框架和相关文献,运用结构方程方法,探查了百度百科用户参与意向的影响因素。结果表明:兴趣动机和态度直接影响参与意向;求知动机、互惠动机和易用性感知通过其他变量间接影响参与意向;有用性感知既直接影响参与意向,又通过其他变量间接影响参与意向。各因素按对参与意向的总影响程度从大到小排序为兴趣动机、有用性感知、易用性感知、求知动机、态度和互惠动机。常静 杨建梅 欧瑞秋 2010软科学2010,24,12:17
19急性呼吸窘迫综合征预后的影响因素探讨显示文摘目的探讨影响急性呼吸窘迫综合征(ARDS)预后的因素。方法对我院呼吸内科重症监护室(R ICU)30例ARDS患者性别、年龄、基础疾病、诱发因素(肺源性、肺外源性)、合并下呼吸道感染、行机械通气、并发多器官功能障碍综合征(MODS)、发病至确诊时间、APACHEⅡ评分、氧合指数(PaO2/F iO2)、C-反应蛋白(CRP)、血清白蛋白(ALB)、血尿素氮(BUN)等因素与其预后的关系行单因素分析。将单因素分析有显著性意义的变量分级并赋值,采用多因素Logistic回归筛选预后因素。结果 30例ARDS患者死亡20例,存活10例。患者的病死率与性别、年龄、诱发因素、合并下呼吸道感染、行机械通气无关。死亡组与存活组患者的APACHEⅡ评分、PaO2/F iO2、CRP、ALB基础值(治疗前)比较差异均无显著性(P>0.05)。既往患基础病、并发MODS、发病至确诊时间长、CRP升高及确诊时BUN指标异常是ARDS患者死亡的独立危险因素。结论既往患基础疾病、并发MODS、发病至确诊时间长、CRP升高与ARDS患者死亡密切相关。槐永军 张绍敏 马壮 陈萍 2010临床军医杂志2010,38,6:17
20Development of highway constructing technology in the permafrost region on the Qinghai-Tibet plateau显示文摘The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surroundings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2―0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate, and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project 'Research on a series of technologies for highway constructing in the permafrost regions' in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engineering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road engineering life in the cold surroundings with high altitude and less oxygen. This article describes a series of technologies for highway constructing according to the special surroundings in the plateau, including some innovative achievements and the research and development of permafrost engineering.WANG ShuangJie CHEN JianBing ZHANG JinZhao LI ZhuLong 2009Science China(Technological Sciences)2009,52,2:16
返回顶部 每页显示:
共52页 首页 上一页 第1页 下一页 末页 /52 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费