全文获取类型
收费全文 | 33556篇 |
免费 | 679篇 |
专业分类
财政金融 | 6078篇 |
工业经济 | 2440篇 |
计划管理 | 5687篇 |
经济学 | 7568篇 |
综合类 | 332篇 |
运输经济 | 227篇 |
旅游经济 | 535篇 |
贸易经济 | 5398篇 |
农业经济 | 1631篇 |
经济概况 | 4234篇 |
信息产业经济 | 3篇 |
邮电经济 | 102篇 |
出版年
2021年 | 220篇 |
2020年 | 388篇 |
2019年 | 593篇 |
2018年 | 662篇 |
2017年 | 712篇 |
2016年 | 699篇 |
2015年 | 493篇 |
2014年 | 772篇 |
2013年 | 3378篇 |
2012年 | 1068篇 |
2011年 | 1099篇 |
2010年 | 967篇 |
2009年 | 1064篇 |
2008年 | 1011篇 |
2007年 | 881篇 |
2006年 | 835篇 |
2005年 | 744篇 |
2004年 | 637篇 |
2003年 | 677篇 |
2002年 | 621篇 |
2001年 | 689篇 |
2000年 | 653篇 |
1999年 | 638篇 |
1998年 | 665篇 |
1997年 | 598篇 |
1996年 | 590篇 |
1995年 | 521篇 |
1994年 | 523篇 |
1993年 | 537篇 |
1992年 | 533篇 |
1991年 | 553篇 |
1990年 | 477篇 |
1989年 | 406篇 |
1988年 | 396篇 |
1987年 | 389篇 |
1986年 | 370篇 |
1985年 | 581篇 |
1984年 | 569篇 |
1983年 | 527篇 |
1982年 | 472篇 |
1981年 | 459篇 |
1980年 | 473篇 |
1979年 | 457篇 |
1978年 | 365篇 |
1977年 | 336篇 |
1976年 | 314篇 |
1975年 | 286篇 |
1974年 | 269篇 |
1973年 | 263篇 |
1972年 | 184篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
An Empirical Look at Software Patents 总被引:4,自引:1,他引:4
Software patents have grown rapidly in number and now comprise 15% of all patents. They are acquired primarily by large manufacturing firms in industries known for strategic patenting; only 5% belong to software publishers. The very large increase in software patent propensity over time is not adequately explained by changes in R&D investments, employment of computer programmers, or productivity growth. The residual increase in software patent propensity is consistent with a sizeable increase in the cost effectiveness of software patents during the 1990s, perhaps arising from changes in the application of patent law to computer software. 相似文献
992.
To study the optimal age-specific labor demand and human capital investment at the firm level we extend the standard dynamic labor demand model by introducing ‘age’ as a second dynamic variable and distinguish between two types of workers: ‘low skilled’ and ‘high skilled’. Applying an age-structured optimal control model we derive qualitative features of the optimal age-specific hiring and training effort. For the case of a linear revenue and production function we prove that firms do not anticipate changes in adjustment costs in their optimal decisions. This result no longer holds if a nonlinear revenue or production function is considered. 相似文献
993.
Remaining life estimation of used components in consumer products: Life cycle data analysis by Weibull and artificial neural networks 总被引:1,自引:1,他引:1
Environmental awareness and legislative pressures have made manufacturers responsible for the take-back and end-of-life treatment of their products. To competitively exploit these products, one option is to incorporate used components in “new” or remanufactured products. However, this option is partly limited by a firm's ability to assess the reliability of used components. A comprehensive two-step approach is proposed. The first stage phase statistically analyzes the behavior of components for reuse. A well-known reliability assessment method, the Weibull analysis, is applied to the time-to-failure data to assess the mean life of components. In the second phase, the degradation and condition monitoring data are analyzed by developing an artificial neural network (ANN) model. The advantages of this approach over traditional approaches employing multiple regression analysis are highlighted with empirical data from a consumer product. Finally, the Weibull analysis and the ANN model are then integrated to assess the remaining useful life of components for reuse. This is a critical advance in sustainable management of supply chains since it allows for a better understanding of not only service requirements of product, but the remaining life in a product and hence its suitability for reuse or remanufacture. Future work should assess: (1) reduction in downtime of process equipment through the implementation of this technique as a means to better manage preventative maintenance; (2) reduce field failure of remanufactured product; (3) selling-service strategy through implementation of the proposed methodology. 相似文献
994.
A multilevel, identity-based approach to leadership development 总被引:1,自引:0,他引:1
A frontier of leadership development is examined involving the respective roles of levels-of-analysis and identity in constructing an integrated development system. An approach is described in which individual and relational leadership identities are the focus of developmental efforts at lower organizational levels (e.g., individual contributor and first-level supervisor) but collective identities become the focus at higher levels (e.g., general manager and above). The separate areas of levels-of-analysis and leader identities are first discussed in terms of their respective relevance to leadership development. These are then discussed jointly in elaborating on a proposed development approach that integrates across organizational levels as well as levels of development (i.e., leader development and leadership development). In developing collective leadership identities, processes that involve participants in engaging across boundaries (functional, hierarchical, geographical) are recommended. 相似文献
995.
This paper focuses on: (1) how a select set of financial and economic factors could set the path for interest rates and foreign exchange rates, and (2) whether the resultant realized interest and exchange rates would be in harmony or in disarray. Using post-euro data for the EU and the US, an array of monetary rules is examined. In particular, the paper investigates whether the original and the extended Taylor rules provide an explanation of the dynamics of the EU monetary system since the inception of the euro. Our findings indicate that the EU and the US monetary responses are not the same and that exchange rates play a significant role. 相似文献
996.
J. Castellano-Paulis A. Hernández-Mendo Verónica Morales-Sánchez M. T. Anguera-Argilaga 《Quality and Quantity》2007,41(1):93-104
We present a probabilistic model based on the one developed by Hernández Mendo and Anguera (Revista de Psicologíca Social,
16(1), 71–93, 2001). Here we have tried to break down the interaction contexts that the opposing teams are able to generate
and transform during the game. We are aware that a given player or team does not produce consistent behaviour in similar situations.
However, a degree of uncertainty is assumed to exist regarding whether the results obtained are a specific function of the
analysis used. In order to carry out this research a category system which optimized that used in the previous model was developed.
This system should enable the interaction between teams to be observed within the actual play of a soccer game. A lag sequential
analysis was performed on the basis of a coding of the behavioural flow. After describing the behavioural patterns obtained
a probabilistic model of the development of play in soccer is proposed. 相似文献
997.
In this paper, progressive stress accelerated life tests are considered when the lifetime of a product under use condition
follows a finite mixture of distributions. The experiment is performed when each of the components in the mixture follows
a general class of distributions which includes, among others, the Weibull, compound Weibull, power function, Gompertz and
compound Gompertz distributions. It is assumed that the scale parameter of each component satisfies the inverse power low,
the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress
holds. Based on type-I censoring, the maximum likelihood estimates (MLEs) of the parameters under consideration are obtained.
A special attention is paid to a mixture of two Rayleigh components. Simulation results are carried out to study the precision
of the MLEs and to obtain confidence intervals for the parameters involved. 相似文献
998.
Raymond Nam Cam Trau Charmine Emma Jean Härtel 《Employee Responsibilities and Rights Journal》2007,19(3):207-219
With the current political environment (such as new legislation recognising gay and lesbian couples) and societal changes
(such as increasing disclosure of sexual identity in the workplace) in countries such as the USA and Australia, organizations
are increasingly recognising the existence of their gay and lesbian employees. This paper reports on an on-line survey of
581 working gay men, examining their quality of work life and career attitudes. The findings of the research provide a strong
indication that contextual factors affect the quality of work life and work attitudes of gay men. 相似文献
999.
In this paper characterizations of negative multinomial distributions based on conditional distributions have been studied. 相似文献
1000.
In this paper, we propose an estimator for the population mean when some observations on the study and auxiliary variables
are missing from the sample. The proposed estimator is valid for any unequal probability sampling design, and is based upon
the pseudo empirical likelihood method. The proposed estimator is compared with other estimators in a simulation study. 相似文献