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911.
912.
The header stack-barge was a device that farmers on the American and Canadian plains invented to adapt wheat harvesting machinery to the special requirements of their semi-arid region. Although it appeared at points scattered throughout the length of the North American plains, its greatest use was in Alberta and Saskatchewan during the 1930s. The development of the header stack-barge was an outstanding example of folk technology in the agricultural history of the Great Plains, showing the conditions under which folk invention might flourish and the way it might interact with government extension agents. The case of the header stack-barge then is of consequence both to folklore and to concepts of Great Plains regionalism. 相似文献
913.
Devinder K. Gandhi 《决策科学》1979,10(3):371-386
An important question with respect to government incentive contracts that has received little attention is: What alternatives to the current practice of making single-stage choices of incentive sharing rates can lead to situations in which these sharing rates can be chosen under reduced risk or cost uncertainty? This paper provides a decision-theoretic framework that illustrates a possibility of reducing risk, from the viewpoints of both the contracting parties, given some negotiated estimate of costs to be incurred. It is shown that such a possibility can arise in a situation in which it is technically feasible to separate or partition the contractual work into closely related tasks or units. Specifically, it is demonstrated that for a given cost estimate (target cost) and target profit, a set of optimal sharing rates (one for each unit) yields a higher risk-adjusted value of the contract than the single-stage sharing rate for the entire contract. 相似文献
914.
Reply 总被引:2,自引:0,他引:2
915.
We use data from the 1931, 1941, and 1951 censuses of India and the 1951 census of Pakistan to examine the demographic consequences of Partition in the Punjab in 1947. Had growth rates for the period 1931-41 for the Punjab as a whole continued to 1951, the population of the Punjab would have been 2.9 million larger than that recorded in 1951. Population losses from migration and mortality above age 20 were approximately 2.7 million greater between 1941 and 1951 than would have been predicted by loss rates between 1931 and 1941. We estimate a net Partition-related population movement out of the combined Punjab of about 400,000. We conclude from several lines of analysis that Partition-related population losses in the Punjab, either from deaths or unrecorded migration, were in the range 2.3-3.2 million. Partition was also marked by a dramatic religious homogenization at the district level. 相似文献
916.
R. D. Blanchard-Boehm R. A. Earl J. H. Wachter E. J. Hanford 《Population and environment》2008,29(6):292-312
San Antonio, Texas, the seventh largest city in the United States, has experienced steady population growth, since the “boom”
of the 1960s. Projected water shortages due to this growth were realized as early as the 1970s by city leaders and south-central
Texas regional development decision makers. To reduce dependence on the already over-taxed, Edwards aquifer, a solution, the
Applewhite Dam and Reservoir Project, was developed with wide acceptance by federal, state, and city leaders who regarded
the project as a necessary measure for regional growth and development. However, opposition by taxpayer and environmental
groups led to referendums of 1991 and 1994 in which voters blocked construction of the dam and reservoir leaving the city
with limited options for water provision. This case study investigated the factors which led to a clear mismatch in communication
between decision makers—those who were aware of the actual and quantifiable risk to the region in terms of reduced water supplies—and
the general public, a population that did not have complete and/or adequate knowledge of their actual risk regarding future
water shortages, nor, of solutions being developed, such as the Applewhite project. The findings from this case study indicate
that when municipal leadership fails to adequately communicate risk regarding resource shortage to an affected public, as
well as, openly planned solutions, that voters are likely to underestimate future impacts of water shortages, heed last-minute
opposition, and reject long-standing, publicly proposed projects. The intent of this research is not to support either side
in the Applewhite controversy, but to shed perspective on the process of adequately and effectively communicating future water
needs to an at-risk population. Decision makers in cities across the United States who are faced with solving problems of
limited resources needed by a large populace may be informed by the results of this research. 相似文献
917.
Endsjø DO 《Journal of homosexuality》2008,54(1-2):9-20
The association of normative sexuality with the geographical center and sexual deviancy with the geographical periphery represents a pattern of thinking that has stayed with us in different guises throughout history. The article traces this pattern and some of its complex ramifications from the ancient Greeks to the present. 相似文献
918.
Two overseas survey-based scales measuring perceived quality of neighbourhood were adapted and replicated in a New Zealand
context. An Italian study (Bonaiuto, Fornara, and Bonnes. (2003). Landscape and Urban Planning, 65, 41–52) measuring Perceived Residential Environmental Quality (PREQ) and an American study (Carp and Carp. (1982). Journal of Environmental Psychology, 2, 295–312) using the Perceived Environmental Quality Indices (PEQI) were applied to a sample of Auckland residents, separated
into low, medium, and high population density areas. The surveys measured attitudes towards subjects such as noise, neighbours,
accessibility, green areas, welfare services, recreational services, safety, maintenance, environmental health, transport
services, and characteristics of an ideal neighbourhood, and were completed by 369 respondents. Primary analyses examined
differences in perception across the three density groups. The factor structures of both scales were replicated with the Auckland
sample, and differences across densities were found for subscales of the PREQ. The results are discussed in relation to the
cross-cultural similarities of perceived environmental quality, and the concept that environmental satisfaction is based on
balancing aspects of the residential environment is proposed.
This research was conducted for the Foundation for Research, Science, and Technology under contract OPSX401. 相似文献
919.
Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of
mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in
the literature. This paper described the conceptual foundation, research design, data analysis, as well as inferences involved
in a mediation and/or moderation investigation in both experimental and non-experimental (i.e., correlational) contexts. The
essential distinctions between the investigation of mediators and moderators were summarized and juxtaposed in an example
of a causal relationship between test difficulty and test anxiety. In addition, the more elaborate models, moderated mediation
and mediated moderation, the use of structural equation models, and the problems with model misspecification were discussed
conceptually.
相似文献
Bruno D. ZumboEmail: |
920.
This article uses a demographic approach and data from the Health and Retirement Survey, a nationally representative sample of the U.S. population, to investigate sex differences in the length of life lived with heart disease and after a heart attack for persons in the United States age 50 and older. On average, women live longer than men with heart disease. At age 50 women can expect to live 7.9 years and men 6.7 years with heart disease. The average woman experiences heart disease onset three years older and heart attacks 4.4 years older than men. 相似文献