全文获取类型
收费全文 | 626篇 |
免费 | 11篇 |
专业分类
财政金融 | 45篇 |
工业经济 | 74篇 |
计划管理 | 44篇 |
经济学 | 19篇 |
综合类 | 2篇 |
运输经济 | 6篇 |
贸易经济 | 38篇 |
农业经济 | 6篇 |
经济概况 | 7篇 |
水利工程 | 396篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 25篇 |
2012年 | 10篇 |
2011年 | 66篇 |
2010年 | 35篇 |
2009年 | 66篇 |
2008年 | 11篇 |
2007年 | 10篇 |
2006年 | 11篇 |
2005年 | 37篇 |
2004年 | 109篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 21篇 |
2000年 | 8篇 |
1999年 | 21篇 |
1998年 | 24篇 |
1997年 | 15篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 26篇 |
1992年 | 31篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有637条查询结果,搜索用时 265 毫秒
1.
Tim Power 《Revue internationale de statistique》2003,71(1):59-67
This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field. 相似文献
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field. 相似文献
2.
Li Yu-cheng He Ming Dept.of Civil Engineering Dalian Univ.of Technology Dalian P.R.China 《水动力学研究与进展(B辑)》1993,(4)
Based on model test,the statistical distribution of extreme values of wave-current in-line forces acting on vertical circular cylinder is analyzed in this paper.It is shownthat the results calculated by the simplified method,proposed by authors,agree well with the testdata;Weibull distribution is also adoptable in the region of high KC number, and the shapeparameter a and scale parameter β are related well with KC number respectively. 相似文献
3.
Li Wang ping Mechanics Department Huazhong University of Science Technology Wuhan P.R.China Yeo K.S. Khoo B.C. Mechanical Production Engineering Department National University of Singapore 《水动力学研究与进展(B辑)》1999,(3)
1. INTRODUCTIONThemaingoalofthispaperistoexplorethepossibilitytolearnmoreaboutthemechanismofturbulentboundarylayerflowinteractionsanditseffectsoncompliantwallperformance.Therearecertainprerequisiteconditionstofurtherthestudyonthemechanism,i.e.theco… 相似文献
4.
5.
中国石油规划总院市场营销研究所 《国际石油经济》2009,17(9):85-88
2009年8月,全国大部分地区进入施工高峰期,沥青终端需求总量较上月出现明显上升。分区域来看,华东和华南地区在项目需求的支撑下,终端需求大量释放,炼厂出货顺畅;西南地区随着灾后重建项目工程的逐步增多,市场交投气氛也日益活跃;北方市场除河北和山西需求相对较好外,其他市场如西北、东北和山东等,需求均小于预期,市场供需基本平衡。 相似文献
6.
K.A. Al-Abdulqader G. Hannah D.M. Power 《Research in International Business and Finance》2007,21(1):69-86
This paper reports on a questionnaire survey about share valuation practices among investors and their intermediaries in Saudi Arabia. The findings suggest that fundamental analysis is used most by investor respondents where a P/E multiple is applied to an earnings forecast to generate a prediction of future price. However, technical analysis is also used to a much greater extent than in developed markets. Finally, the results indicate that quarterly and annual reports as well as newspapers are widely consulted by investors when forming their expectations about share valuations. 相似文献
7.
Huai Wen-xin Wuhan University of Hydraulic & Electric Engineering Wuhan Hubei P.R.China Prof.Li Wei 《水动力学研究与进展(B辑)》1993,(3)
Turbulence represents an essential aspect in atmospheric and oceanic circulations.In particu-lar,it is a preponderant factor in the dispersion of pollutants of artificial or natural origin.Thevertical turbulent jets,plumes and buoyant jets discharging into static environment is one of themost important and basic flow patterns related with the environment pollution.These flows havenumerous important applications,for example,thrust augmentors,waste disposal plumes fromstacks and combustion systems,and significant problems of turbulent diffusion. 相似文献
8.
Li Jian-zhong Niu Zheng-meng Chen Gang Tan Li-xing Shaanxi Institute of Mechanical Engineering Xi''''an P.R.China 《水动力学研究与进展(B辑)》1993,(4)
This paper will introduce experimental studies and numerical calculation onturbulent boundary layer of water flow along curved surface in our country in recent years.Onthe basis of the experimental studies,the effects of curvature and roughness on velocitydistribution and pressure distribution and the change of turbulent flow boundary layer onoverflow bucket concave surface is discussed.We proposed the empirical formula of velocity,pressure and the change of turbulent flow boundary layer on outlet bucket concave.According tothe momentum principle,we have deduced the momentum integral equation full water depthboundary layer and using the element as control unit inside the boundary layer on concavesurface of bucket.Combining with continuity equation,we have computed the boundary layerdevelopment on the bucket of a spillway.Compared with the field experimental data,thecalculation results are available.Under polar coordinates,a mathematical model for simulatingtime-averaged flow characteristics in concave surface of bucket is established.The turbulent flowfield on concave surface of bucket is calculated by SIMPLE method and this mathematicalmodel.The flow velocity field,pressure field,distribution of turbulent kinetic energy,distribution of turbulent energy dissipating rate and distribution of shear stress are available.Thecalculation value is consistent with measured test data. 相似文献
9.
Special Committee on Pumped-storage Power Plant 《水力发电》1998,(12):50-51
我国台湾省目前有明潭和明湖两座抽水蓄能电站,其装机容量2602 万k W ,占台湾省电力系统总装机容量的101% , 主要用来解决峰谷差的矛盾和提高电网供电质量, 降低系统发电综合成本, 其运行和检修情况良好。台湾省电力公司对这两个直属的抽水蓄能电厂直接负责其建设与运行管理。 相似文献
10.
Liu Xiao-zhou Liu Ying-zhong Miao Guo-ping School of Naval Architecture Ocean Engineering Shanghai Jiaotong University Shanghai China 《水动力学研究与进展(B辑)》2001,(1)
1 . INTRODUCTIONWhenhigh speedairfloworcurrentpassesovergapsorcavitiesinaflatplate ,self excitedoscillationsmayoccur ,leadingtodramaticpressureandvelocityfluctuationandintensivenoise .Thesephenomenamayappearinmanyengineeringapplications .Forexample ,weaponb… 相似文献