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   68202篇
  免费   1609篇
  国内免费   24篇
财政金融   10682篇
工业经济   4364篇
计划管理   10030篇
经济学   13567篇
综合类   752篇
运输经济   392篇
旅游经济   991篇
贸易经济   9807篇
农业经济   2891篇
经济概况   7134篇
水利工程   9064篇
信息产业经济   3篇
邮电经济   158篇
  2021年   498篇
  2020年   753篇
  2019年   1099篇
  2018年   1468篇
  2017年   1443篇
  2016年   1468篇
  2015年   1011篇
  2014年   1548篇
  2013年   6338篇
  2012年   2299篇
  2011年   2317篇
  2010年   1800篇
  2009年   1999篇
  2008年   2211篇
  2007年   2227篇
  2006年   2129篇
  2005年   1930篇
  2004年   1840篇
  2003年   1422篇
  2002年   1314篇
  2001年   1351篇
  2000年   1275篇
  1999年   1140篇
  1998年   1197篇
  1997年   1157篇
  1996年   1151篇
  1995年   1028篇
  1994年   1031篇
  1993年   1056篇
  1992年   1039篇
  1991年   1072篇
  1990年   959篇
  1989年   804篇
  1988年   798篇
  1987年   819篇
  1986年   777篇
  1985年   1139篇
  1984年   1115篇
  1983年   1114篇
  1982年   1019篇
  1981年   973篇
  1980年   952篇
  1979年   948篇
  1978年   795篇
  1977年   700篇
  1976年   646篇
  1975年   555篇
  1974年   533篇
  1973年   506篇
  1972年   387篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
In the light of the increasing pace and scale of tourism activity in New Zealand, the concept of sustainable tourism has become a key ingredient in the nation's tourism strategy. This paper explores sustainable tourism planning in New Zealand at the level of local government, and in particular, focuses on the implementation of the Resource Management Act 1991 (RMA) as a mechanism for achieving sustainable tourism. Using the findings of a survey of Regional Councils and Territorial Local Authorities, the paper explores public sector planning responses to tourism impacts and sustainability concerns in New Zealand. The paper extends the earlier work of Page and Thorn (1997. Towards sustainable tourism planning in New Zealand: public sector planning responses. Journal of Sustainable Tourism 5(1): 59-77; 2002. Towards sustainable tourism development and planning in New Zealand: the public sector response revisited. Journal of Sustainable Tourism 10(3): 222-238), which identified major issues of concern at local council level with regard to tourism impacts and argued the need for a national vision for tourism to ensure that the RMA achieved its original goals. Since then, a national tourism strategy has been published and changes in legislation have further empowered local authorities to further progress the sustainability agenda. This paper examines these developments and the ensuing implications, concluding that significant progress has been made in developing tourism policies at the local level, but that a number of constraints and issues limit the development of New Zealand as a sustainable destination.  相似文献   
912.
While framing theory is concerned with the way media content is presented, news bias theory concentrates on the evaluative aspect. The study integrates both approaches of news structuring. A detailed argument analysis of two German quality newspapers, Die Welt and Frankfurter Rundschau, representative for two opposite editorial viewpoints, was conducted to test the assumptions of both theories. The examination of news coverage related to the accession of Poland, Czech Republic, Bulgaria and Romania to the EU contradicts previous results of framing and news bias research. Apart from finding a pronounced focus on economical topics in both newspapers, they clearly differ in their frames of reference and political positions on the issues, staying in line with their editorial orientation. A comparison of the different accession times reveals a change in the frames of reference and the advocates of these frames.  相似文献   
913.
Statistical Thinking in Empirical Enquiry   总被引:4,自引:0,他引:4  
This paper discusses the thought processes involved in statistical problem solving in the broad sense from problem formulation to conclusions. It draws on the literature and in-depth interviews with statistics students and practising statisticians aimed at uncovering their statistical reasoning processes. From these interviews, a four-dimensional framework has been identified for statistical thinking in empirical enquiry. It includes an investigative cycle, an interrogative cycle, types of thinking and dispositions. We have begun to characterise these processes through models that can be used as a basis for thinking tools or frameworks for the enhancement of problem-solving. Tools of this form would complement the mathematical models used in analysis and address areas of the process of statistical investigation that the mathematical models do not, particularly areas requiring the synthesis of problem-contextual and statistical understanding. The central element of published definitions of statistical thinking is "variation". We further discuss the role of variation in the statistical conception of real-world problems, including the search for causes.  相似文献   
914.
Meat and poultry recalls, while voluntary, are carried out under governmental oversight. If firms have financial incentives to avoid being implicated in a recall situation, governmental involvement in recalls may cause firms to internalize social costs when making investment decisions concerning food safety controls. To examine these incentives, we analyze federally supervised meat and poultry recalls from 1982 to 1998 within an event study. Results show significant shareholder losses when publicly traded food companies are implicated in a recall involving serious food safety hazards. We find no evidence that the stock market reacts negatively when recalls involve less severe hazards.  相似文献   
915.
The sustainable livelihoods (SL) approach offers a holistic framework and a practical toolkit to analyze tourism's impacts and interactions within a community. This study argues that the usefulness of the SL approach in tourism can be enhanced by ensuring that the approach is built on a genuine people-centered starting point. The exploration of the local community's representations of, and aspirations for, their roles in tourism as a future livelihood choice meets this need. To verify the value of this approach empirically, this study examined the case of Lhasa, Tibet, and local youth as the research respondents. The findings suggest that the young hosts in Lhasa urban area were heterogeneous in their responses to tourism as a future livelihood choice. They fell into four subgroups: in-betweeners, ambivalent supporters, alternative supporters, and lovers. Further, this study examined the profiles of these four subgroups and explored their responses. The study enhances the SL approach by taking tourism as an example and clearly defining the departure point for its adoption within the context of broader livelihoods portfolios. Additionally, it suggests some potential directions for tailored management strategies to meet youth and community perspectives.  相似文献   
916.
European governments must recognize the economic significance of the tourism industry to Europe. Dr Klaus Edelmann, Professor at the Swiss School of Tourism Management, describes how modern marketing methods and EEC consensus policies must be adopted to combat increasing competition from outside Europe and expand the domestic market.  相似文献   
917.
To achieve an environmental objective at least cost, decision makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to an environmental outcome are often known, the way in which these attributes interact to produce the outcome is often unknown. We introduce a nonparametric conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds. We apply the approach empirically to the case of conservation contracting for water-quality objectives. The contract portfolios derived from the application have many desirable properties, including intuitive appeal and robust performance across plausible parametric scoring measures.  相似文献   
918.
The long-term structure of production, factor demand and factor productivity in the Canadian pulp and paper industry was studied for the period 1956 to 1982. A four input (labor, capital, material and energy) nonhomothetic translog cost function was used for the purpose. Least-cost combinations of the four factors were obtained by imbedding an interrelated dynamic adjustment process. These least-cost paths, from which the cyclical fluctuations due to business turns were filtered out, were then used to derive the long-term productivity of each input. Long-term elasticities of substitution and demand were also computed. Long-term and short-term results were compared. Important findings of the study were: (i) the long-term structure of production of the industry can be represented by the nomothetic version of the translog cost function, (ii) the long-term technological progress in the industry is slow despite evidence of some economies of scale in production, (iii) all factors of production in the industry are long-run substitutes despite short-run complementarities between some factors of production, (iv) each input was observed to be misallocated during the period of study as compared to the least-cost allocations, (v) observed productivity growth of capital, labor and energy declined during the seventies and early eighties, as compared to growth in the sixties, but growth in their long-run productivities did not, (vi) though both observed and long-run productivities of raw material declined the rate of decline was lower on the long-run path, and (vii) price increases in the pulp and paper industry after 1971 could have been lower than what was actually experienced if the industry could change with economic circumstances more rapidly. La structure à long terme de production, de facteur de demande et de facteur de productivité dans l'industrie canadienne de putpe et de papier est étudiée pour la période de 1956 à 1982. Une fonction de coût “nonhomothetic translog” avec quatre entrées (la main-d'oeuvre, le capital, le matériel et l‘énergie) est utilisée pour cette étude. Les combinaisons les moins chères des quatre facteurs sont obtenues en incluant un ajustement dynamique du processus d'interaction. Ces chemins les moins chers, desquels les fluctuations conjoncturelles dues aux changements d'affaires sont enlevées, sont utilisés pour dériver la productivité à long terme de chaque entrée. Les élasticités à long terme de substitution et de demande sont aussi calculées. Les résultats à long terme et ceux à court terme sont comparés. Les découvertes importantes de cette étude sont: (i) la structure à long terme de production de l’-industrie peut être représentée par la version “homothetic” de la fonction de coût “translog,” (ii) le progrès technologique à long terme dans l'industrie est lent malgré l‘évidence de certaines économies par la production à grande échelle, (iii) tous les facteurs de production dans l'industrie sont des substituts à long terme malgré les complémentarités à court terme parmi les facteurs de production, (iv) chaque entrée était allouée au mauvais endroit pendant la période d’étude à comparaison des allocations les moins chères, (v) la croissance de productivité observée de capital, de main-d'oeuvre et d‘énergie a diminué pendant les années soixante-dix et au début des années quatre-vingts, à comparaison de la croissance dans les années soixante, mais la croissance de leurs productivités à long terme n'a pas diminué, (vi) bien que les productivités observées et à long terme de matières premières ont diminué, les taux de diminution sont plus bas sur le chemin à long terme, et (vii) les augmentations de prix dans l'industrie de pulpe et de papier après 1971 auraient pu être plus bas qu'on n'a expérimenté si l'industrie était capable de changer plus rapidement selon les circonstances économiques.  相似文献   
919.
A highly controversial and debated question is the ultimate cause of desertification. Is it due more to man or to nature? This article addresses this important question and, by use of examples from the Dust Bowl of the USA in the 1930s, argues that drought does not necessarily cause desertification, but that the actions of mankind do. In the 1930s, in the absence of land management legislation or policy, a drought resulted in severe land degradation. In the 1950s in the same area a drought went largely unnoticed, due mainly to the effective soil conservation measures and large-scale investments in infrastructure that had been imposed since the 1930s. Desertification is bound to continue in the absence of effective policy, planning and development.  相似文献   
920.
A J Hogan  J E Rohrer 《Socio》1987,21(4):245-250
This study analyzes the variance reduction capabilities of three existing nursing home patient classification systems across different shifts and sub-week time periods. The existing classification systems, all based on nursing time data collected in the middle of the working week, performed well with data collected at night and on weekends. Existing nursing home patient classification systems are robust for time periods other than those during which nursing times have usually been collected.  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