首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1571篇
  免费   18篇
管理学   450篇
民族学   7篇
人才学   2篇
人口学   190篇
丛书文集   2篇
理论方法论   56篇
综合类   8篇
社会学   776篇
统计学   98篇
  2023年   6篇
  2020年   9篇
  2019年   7篇
  2018年   10篇
  2017年   19篇
  2016年   14篇
  2015年   10篇
  2014年   62篇
  2013年   230篇
  2012年   122篇
  2011年   99篇
  2010年   79篇
  2009年   90篇
  2008年   31篇
  2007年   55篇
  2006年   109篇
  2005年   31篇
  2004年   36篇
  2003年   67篇
  2002年   52篇
  2001年   71篇
  2000年   50篇
  1999年   7篇
  1998年   9篇
  1997年   8篇
  1996年   46篇
  1995年   52篇
  1994年   53篇
  1993年   19篇
  1992年   12篇
  1991年   5篇
  1990年   6篇
  1989年   8篇
  1988年   8篇
  1987年   3篇
  1986年   7篇
  1984年   4篇
  1983年   4篇
  1982年   10篇
  1981年   5篇
  1980年   13篇
  1979年   19篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1973年   3篇
  1972年   2篇
  1971年   5篇
  1969年   3篇
  1968年   2篇
排序方式: 共有1589条查询结果,搜索用时 593 毫秒
281.
The accounting for pension obligations is based upon numerous parameters, whose future developments must be forecasted for valuation purposes. If the actual realizations of theses parameters deviate from their original estimations there are generated so-called actuarial gains and losses. IAS 19 provides three alternative accounting treatments with respect to these actuarial gains and losses. In particular the equity and the corridor approach, both frequently used in practice, implicitly assume that the actuarial gains and losses offset each other in the long run. However different studies have demonstrated by using the Monte-Carlo-Simulation-technique that this long-term offset is not assured. But those studies do not propose a rationale for the observed generation of systematic actuarial gains and losses. The present paper provides an analytic rationale for the systematic appearance of actuarial gains and losses and comes to the following conclusion: The long-term offset of actuarial gains and losses is assured only if the parameters that must be estimated for valuation purposes are independent. However if there is an interdependence between those parameters, which seems to be a sound assumption in reality, the offset of actuarial gains and losses is not given. In case of a positive correlation actuarial losses are generated on a systematic basis, whereas a negative correlation results in actuarial gains.  相似文献   
282.
283.
Since Ulrich (Human resource champions: the next agenda for adding value and delivering results, Boston, Harvard Business School Press, 1997) shaped the strategic role of HR managers, his concept of an HR business partner has been controversially discussed by researchers and practitioners. Explanations about when and how HR managers act as strategic business partners have found limited attention in the literature. Based on the theory of reasoned action developed by Ajzen und Fishbein (Understanding attitudes and predicting social behavior, Englewood Cliffs, Prentice-Hall, 1980; J Pers Soc Psychol 27(1):41?C57, 1973), we hypothesize a positive relation between personal attitudes as well as subjective norm and the behaviour of HR managers to act as a strategic business partner. Results of the German Cranet survey in 2009 show that expected positive consequences influence the personal attitude, whereas the acceptance of the human resources as well as the existence of an HR strategy within the organisation is positively related with subjective norm. Hence, both attitude and subjective norm positively influence the behaviour of HR managers to act as a strategic business partner.  相似文献   
284.
285.
This study evaluates the social and demographic structure of poverty migration during the 1985–90 period based on an analysis of recent census data. Particular attention is given to the roles of two policy-relevant factors that are proposed to be linked to poverty migration. The first of these is the role of immigration from abroad and its effect on the net out-migration of longer-term residents with below-poverty incomes, from States receiving the highest volume of immigrants. Such a response, it is argued, could result from job competition or other economic and social costs associated with immigration. The second involves the poverty population magnet effect associated with State welfare benefits (AFDC and Food Stamp payments) which has come under renewed scrutiny in light of the impending reform of the federal welfare program. The impact of both of these factors on interstate poverty migration is evaluated in a broader context that takes cognizance of other sociodemographic subgroups, and State-level attributes that are known to be relevant in explaining internal migration. This research employs an exceptionally rich data base of aggregate migration flows, specially tabulated from the full migration sample of the 1990 US census (based on the residence 5 years ago question). It also employs an analysis technique, the nested logit model, which identifies separately the push and pull effects of immigration, welfare benefits, and other State attributes on the migration process. Our findings are fairly clear. The high volume of immigration to selected US Statesdoes affect a selective out-migration of the poverty population, which is stronger for whites, Blacks and other non-Asian minorities as well as the least-educated. These results are consistent with arguments that internal migrants are responding to labor market competition from similarly educated immigrants. Moreover, we found that the impact of immigration occurs primarily as a push rather than a reduced pull. In contrast, State welfare benefits exert only minimal effects on the interstate migration of the poverty population—either as pulls or pushes, although some demographic segments of that population are more prone to respond than others. In addition to these findings, our results reveal the strong impact that a State's racial and ethnic composition exerts in both retaining and attracting migrants of like race and ethnic groups. This suggests the potential for a greater cross-state division in the US poverty population, by race and ethnic status.Data Used: 1990 US census tabulations of full migration (residence 5 years ago) sample. Note: Detailed 1990 census statistics on migration of the poverty and nonpoverty populations for individual states can be found in: William H. Frey Immigration and Internal Migration for US States: 1990 Census Findings by Poverty Status and Race, Population Studies CenterResearch Report No. 94-320.This research is supported by the University of Wisconsin Institute for Research on Poverty Small Grants Program and by NICHD grant No. R01 HD29725. The migration data for this paper were prepared at the Population Studies Center, University of Michigan from 1990 US Census files. The authors acknowledge Cathy Sun for computer programming assistance, and Ron Lue-Sang for preparing maps and graphics.  相似文献   
286.
Large scale immigration to the United States and a sluggish national economy have brought to the forefront of the current immigration policy debate, the question of whether immigrants fully pay—in the form of taxes—for the public services they use. Recent estimates of the costs of immigration differ so widely that they have confused rather than enlightened that debate. This paper argues that a uniform accounting framework must be agreed to if future studies are to provide credible and reliable estimates of costs and benefits upon which immigration policy can be formulated. The key conceptual, factual, and accounting issues that are to be addressed for the development of such a framework are outlined.  相似文献   
287.
This text addresses the critiques from the Urban Institute and other immigrant advocacy groups concerning the findings of an earlier study, The Cost of Immigration released in the summer of 1993. That study showed that the public costs associated withimmigrants settling here since 1970 amounted, in 1992, to $42.5 billion more in services and assistance than the $20.2 billion which immigrants paid in taxes (Huddle, 1993). The updated assessment takes into account previously unavailable figures and revises some methods and assumptions used in the earlier work. The updated bottom line is fully consistent with initial findings on immigrant costs for 1992.  相似文献   
288.
There is nothing static about the notion of optimum population. For any given country, region or the world, the optimum population, or maximum acceptable population, depends on a host of related factors: aspirations of a material kind, the state of the environment, the ability of the economy to provide food, shelter, transport, services, consumer durables and other needs. Many countries, such as the U.K., while today enjoying a reasonable standard of living, may not in fact be living within their carrying capacities. The relation between population and development is a dynamic one. Where the trends established by past and current policies are potentially unsustainable, then there is the risk that population levels may compromise the prospects of maintaining living standards and attaining environmental objectives.This paper draws on the recent world modelGlobEcco, to explore the implications of alternative population growth rates for the future of both the industrialised and developing regions of the world. The model is based on ECCO (Evolution of Capital Creation—previously Carrying Capacity—Options): a new integrative procedure which can test out strategies, technologies and rates of population growth aimed at satisfying both economic and environmental aspirations over the long term.  相似文献   
289.
Estimating human population carrying capacity for subglobal areas is problematic due to interregional transfers of energy, resources, pollution and waste. However, recent research on Chesapeake Bay sediment has permitted determination of time of onset of major episodes of Bay degradation, which may be used with census data to derive preliminary estimates of the watershed's carrying capacity.Chesapeake Bay, the United States' largest estuary, is experiencing increasing degradation despite a decade of studies and significant remedial activity. Since 1985, phosphorus emissions declined 18%, due mainly to a ban on phosphate detergent, but nitrogen increased at least 2%. Degrading influences, related to increasing fossil-fuel consumption and relentless population growth, include (1) overharvesting of shellfish and fish species, (2) nitrogen emissions from sewage treatment plants, agriculture, fossil-fueled power plants and motor vehicles, (3) phosphorus emissions from sewage and agriculture, (4) debris, sewage, fuel spills and exhaust from 400,000 registered watercraft, (5) storm-water runoff, (6) sedimentation from land-use changes, (7) industrial discharges, (8) construction of dams and other barriers to anadromous fish migration, and (9) disposal of dredged material.Oyster harvests have declined over 95% in Virginia since the 1950s. Submerged aquatic vegetation (SAV), essential to fish and bottom-dwelling invertebrates, is estimated to cover only 10% of its pre-1950 distribution. Where remediation efforts have resulted in recolonization of SAV, species diversity is reduced 50–90%. Anoxic conditions are persistent in the Bay's deeper waters.New sediment data allow precise determination of time of onset of degration by recognizing changes in ratio of benthic to planktonic diatoms. These data, coupled with analyses of living resource populations, indicate that the most significant episode of Bay degradation commenced in the 1950s, and suggest that the human population carrying capacity for the watershed does not exceed 8 million without substantial changes in energy consumption and lifestyle. The watershed's present population of 16 million is projected to increase at least 20% by 2020. Furthermore, registration of motor vehicles may increase by one-third over the same interval. Goals of 40% reduction by 2000 of nitrogen and phosphorus emissions into the Bay set by the Chesapeake Bay Commission are unattainable without permanent changes in behavior affecting every facet of life in the watershed. The extent to which remediation efforts are successful in the Bay's watershed will help define much of the structure and nature of U.S. society in the twenty-first century.  相似文献   
290.
Life on Earth is driven by energy. Autotrophs take it from solar radiation and heterotrophs take it from autotrophs. Energy captured slowly by photosynthesis is stored up, and as denser reservoirs of energy have come into being over the course of Earth's history, heterotrophs that could use more energy evolved to exploit them.Homo sapiens is such a heterotroph; indeed, the ability to use energy extra-somatically (outside the body) enables human beings to use far more energy than any other heterotroph that has ever evolved. The control of fire and the exploitation of fossil fuels have made it possible forHomo sapiens to release, in a short time, vast amounts of energy that accumulated long before the species appeared.By using extrasomatic energy to modify more and more of its environment to suit human needs, the human population effectively expanded its resource base so that for long periods it has exceeded contemporary requirements. This allowed an expansion of population similar to that of species introduced into extremely propitious new habitats, such as rabbits in Australia or Japanese beetles in the United States. The world's present population of over 5.5 billion is sustained and continues to grow through the use of extrasomatic energy.But the exhaustion of fossil fuels, which supply three quarters of this energy, is not far off, and no other energy source is abundant and cheap enough to take their place. A collapse of the earth's human population cannot be more than a few years away. If there are survivors, they will not be able to carry on the cultural traditions of civilization, which require abundant, cheap energy. It is unlikely, however, that the species itself can long persist without the energy whose exploitation is so much a part of itsmodus vivendi.The human species may be seen as having evolved in the service of entropy, and it cannot be expected to outlast the dense accumulations of energy that have helped define its niche. Human beings like to believe they are in control of their destiny, but when the history of life on Earth is seen in perspective, the evolution ofHomo sapiens is merely a transient episode that acts to redress the planet's energy balance.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号