全文获取类型
收费全文 | 26050篇 |
免费 | 509篇 |
国内免费 | 13篇 |
专业分类
财政金融 | 4847篇 |
工业经济 | 1978篇 |
计划管理 | 4147篇 |
经济学 | 5612篇 |
综合类 | 753篇 |
运输经济 | 162篇 |
旅游经济 | 464篇 |
贸易经济 | 4203篇 |
农业经济 | 1330篇 |
经济概况 | 3042篇 |
邮电经济 | 34篇 |
出版年
2021年 | 145篇 |
2020年 | 281篇 |
2019年 | 403篇 |
2018年 | 477篇 |
2017年 | 532篇 |
2016年 | 478篇 |
2015年 | 365篇 |
2014年 | 551篇 |
2013年 | 2555篇 |
2012年 | 651篇 |
2011年 | 753篇 |
2010年 | 689篇 |
2009年 | 713篇 |
2008年 | 807篇 |
2007年 | 714篇 |
2006年 | 558篇 |
2005年 | 552篇 |
2004年 | 524篇 |
2003年 | 545篇 |
2002年 | 524篇 |
2001年 | 529篇 |
2000年 | 574篇 |
1999年 | 463篇 |
1998年 | 493篇 |
1997年 | 508篇 |
1996年 | 477篇 |
1995年 | 446篇 |
1994年 | 449篇 |
1993年 | 505篇 |
1992年 | 473篇 |
1991年 | 444篇 |
1990年 | 410篇 |
1989年 | 350篇 |
1988年 | 313篇 |
1987年 | 324篇 |
1986年 | 344篇 |
1985年 | 479篇 |
1984年 | 535篇 |
1983年 | 488篇 |
1982年 | 460篇 |
1981年 | 479篇 |
1980年 | 415篇 |
1979年 | 432篇 |
1978年 | 340篇 |
1977年 | 331篇 |
1976年 | 294篇 |
1975年 | 229篇 |
1974年 | 232篇 |
1973年 | 209篇 |
1972年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Summary Completeness of a family of probability distributions implies its bounded completeness but not conversely. An example of a
family which is boundedly complete but not complete was presented by Lehmann and Scheffe [5]. This appears to be the only
such example quoted in the statistical literature. The purpose of this note is to provide further examples of this type. It
is shown that any given family of power series distributions can be used to construct a class containing infinitely many boundedly
complete, but not complete, families. Furthermore, it is shown that the family of continuous distributions
, is boundedly complete, but not complete, whereU denotes the uniform distribution on [a, b] and {P
ϑ,ϑ ∈ IR}, is a translation family generated by a distributionP
0 with mean value zero, which is continuous with respect to the Lebesgue measure. 相似文献
112.
D Taylor 《Development Southern Africa》1988,5(4):465-481
The various agricultural practices employed in eastern Maputaland are described.
Agricultural strategies utilized in Maputaland are low in productivity but aim to minimize risk. The area is marginal for agriculture as soils are sandy and rainfall unreliable. Insects and plant diseases accentuate the problem. Infrastructure is lacking in the area. Traditional agricultural systems predominate.
Farming in the area is generally of a subsistence nature and can be divided into gardening, swamp farming and field cropping. Steps towards modernization of agriculture must take into account all existing constraints. 相似文献
113.
114.
Assessing and acquiring technology does not have to be chaotic, driven solely by price, clinical preference, and emotion. With the tools available, it can be distilled to a process of organized common sense, which results in maximum flexibility for the user and allows materiel managers to procure the best, most cost-effective equipment for the hospital. 相似文献
115.
Karp D 《Medical economics》1992,69(16):128-9, 133-5
116.
117.
Brendel D 《Fund raising management》1992,23(2):42-44
Responding to donor complaints takes great care. But know who's complaining and keep things in perspective. 相似文献
118.
Yankelovich D 《Fortune》1992,126(7):102-4, 108
The public's thinking on issues progresses through seven predictable stages, the dean of American pollsters finds. Politicians make a big mistake just looking at raw numbers. 相似文献
119.
An aging population with nearly unlimited access to high-priced doctors and technology is pushing medical costs skyward. Managed care is the best way to bring them down. 相似文献
120.
Richman LS 《Fortune》1992,126(3):34-40
Many more than ever face the crises of childhood: violence, drugs, bad schools, poverty, divorce, or two parents at work. And no one seems to care. 相似文献