全文获取类型
收费全文 | 38658篇 |
免费 | 615篇 |
专业分类
财政金融 | 6594篇 |
工业经济 | 2321篇 |
计划管理 | 6366篇 |
经济学 | 9094篇 |
综合类 | 675篇 |
运输经济 | 184篇 |
旅游经济 | 347篇 |
贸易经济 | 7990篇 |
农业经济 | 1144篇 |
经济概况 | 3876篇 |
信息产业经济 | 46篇 |
邮电经济 | 636篇 |
出版年
2023年 | 111篇 |
2021年 | 152篇 |
2020年 | 287篇 |
2019年 | 464篇 |
2018年 | 2699篇 |
2017年 | 2482篇 |
2016年 | 1679篇 |
2015年 | 436篇 |
2014年 | 645篇 |
2013年 | 2468篇 |
2012年 | 1195篇 |
2011年 | 2644篇 |
2010年 | 2438篇 |
2009年 | 2219篇 |
2008年 | 2151篇 |
2007年 | 2402篇 |
2006年 | 672篇 |
2005年 | 894篇 |
2004年 | 896篇 |
2003年 | 997篇 |
2002年 | 663篇 |
2001年 | 559篇 |
2000年 | 505篇 |
1999年 | 415篇 |
1998年 | 486篇 |
1997年 | 425篇 |
1996年 | 436篇 |
1995年 | 359篇 |
1994年 | 370篇 |
1993年 | 354篇 |
1992年 | 363篇 |
1991年 | 381篇 |
1990年 | 345篇 |
1989年 | 255篇 |
1988年 | 264篇 |
1987年 | 267篇 |
1986年 | 262篇 |
1985年 | 359篇 |
1984年 | 357篇 |
1983年 | 332篇 |
1982年 | 284篇 |
1981年 | 286篇 |
1980年 | 283篇 |
1979年 | 277篇 |
1978年 | 226篇 |
1977年 | 183篇 |
1976年 | 182篇 |
1975年 | 162篇 |
1974年 | 149篇 |
1973年 | 148篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Innovation is the engine of development for enterprises, and there is an increasing trend to adopt an open innovation strategy. However, how to manage external resources in an open, collaborative and complementary manner, and in a shared environment that will yield the greatest networking effects, it is a challenging task. Because there is no such a satisfactory model for an open innovation strategy that combine operational mechanisms with the management of, external resources. Thhis article tries to fill the gap by adopting a resource-based perspective to construct an overall open innovation (OOI) business model. In this model, external resources are classified as industrial and non-industrial entities, to enable the identification of the interaction methods between manufacturing enterprises and external resources. The management of external resources involved in a Technology Open Innovation (TOI) cycle is given particular attention that includes: 1) the classification of the external resources of a TOI, 2) the general mechanisms extracted to promote qualified resources in and unqualified resources out, and 3) a business model to conceptualize the collaboration between enterprises and external resources. A case study of TOI is also provided to empirically verify its feasibility. This paper contributes to the literature by providing an original operational model and mechanism design for an open innovation strategy that is capable of managing external resources effectively. 相似文献
992.
L. J. Dijkstra A. V. Yakushev P. A. C. Duijn A. V. Boukhanovsky P. M. A. Sloot 《Quality and Quantity》2014,48(5):2739-2755
The criminal nature of narcotics complicates the direct assessment of a drug community, while having a good understanding of the type of people drawn or currently using drugs is vital for finding effective intervening strategies. Especially for the Russian Federation this is of immediate concern given the dramatic increase it has seen in drug abuse since the fall of the Soviet Union in the early nineties. Using unique data from the Russian social network ‘LiveJournal’ with over 39 million registered users worldwide, we were able for the first time to identify the on-line drug community by context sensitive text mining of the users’ blogs using a dictionary of known drug-related official and ‘slang’ terminology. By comparing the interests of the users that most actively spread information on narcotics over the network with the interests of the individuals outside the on-line drug community, we found that the ‘average’ drug user in the Russian Federation is generally mostly interested in topics such as Russian rock, non-traditional medicine, UFOs, Buddhism, yoga and the occult. We identify three distinct scale-free sub-networks of users which can be uniquely classified as being either ‘infectious’, ‘susceptible’ or ‘immune’. 相似文献
993.
Stefan Christiansen 《保险科学杂志》2017,106(5):447-451
Digitalisation of the health care system proceeds. Therefore it is to be expected that telemedicine applications will also be introduced into health care. Currently, the number of telemedicine applications in Germany is low and it is also scarce in comparison to foreign countries. This is striking because it is usually supposed that telemedicine applications have got a great potential to improve health care and reduce expenditures. Hence, this publication discusses offers, chances and the cost-effectiveness of telemedicine. 相似文献
994.
High-quality science communication to the public depends to a large extent on the way research findings are translated into comprehensible language and common speech. In this communicative process, a reasonable evaluation of the trustworthiness of empirical findings, based on an adequate interpretation of statistical analyses, is absolutely crucial. This paper’s authors argue that the credibility of science is jeopardised by two compromising developments within science itself: on the one hand, an inflation of ostensible empirical evidence related to misuses and misinterpretations of the concept of statistical significance, and, on the other, a sensationalist overvaluation of the results of single studies instead of an adequate representation of the available body of evidence in a given scientific field. 相似文献
995.
Ryan M. Roberts Kelly W. Jones Andrew Seidl Audrey Ek Hannah Smith 《Journal of Sustainable Tourism》2017,25(10):1353-1366
Protected areas are key to the conservation of global biodiversity and ecosystem services; however, their success is contingent upon adequate funding. One possibility to increase funding for park management is to “sell” a wider suite of ecosystem services “produced” by protected areas, such as carbon sequestration. We conducted 420 tourist surveys to analyze willingness to pay (WTP) for ecosystem service benefits via a conservation fee in the Tambopata National Reserve in Peru. We also interviewed eight tour operators about their perceptions of the proposed fee. The average stated WTP was 15 USD. Sixty-six percent of tourists stated they would pay 10 USD or more, which, if actually paid, would have resulted in 318,000 USD for park management in 2015. Most respondents stated they would pay an additional fee if it supported biodiversity conservation or local ecosystem services, such as water, but less than 10% of tourists were motivated by carbon sequestration as a reason to pay the fee. Most tour operators supported the additional fee. Our findings suggest that tourists are willing to pay higher fees to support conservation but that interest in paying for additional ecosystem services from parks may not extend to global and intangible benefits such as carbon sequestration. 相似文献
996.
David A. Welch 《Group Decision and Negotiation》2017,26(1):71-92
Many of the most active and most dangerous security challenges in the Asia-Pacific region are generally seen to involve a complex amalgam of material and ideational conflicts. There is surprisingly little consideration, however, of the role of the justice motive. This article explores the role of the justice motive in the context of three specific maritime and territorial disputes: Dokdo/Takeshima, the Senkaku/Diaoyu Islands, and the South China Sea. What explains its intensity? How does it affect political salience, tractability, and danger of conflict? What are the available mechanisms and prospects for resolving justice conflicts? 相似文献
997.
Rana Rizk Mickaël Hiligsmann Mirey Karavetian Silvia M. A. A. Evers 《Journal of medical economics》2017,20(10):1024-1038
Aim: To assess the cost-effectiveness of nutrition education by dedicated dietitians (DD) for hyperphosphatemia management among hemodialysis patients.Materials and methods: This was a trial-based economic evaluation in 12 Lebanese hospital-based units. In total, 545 prevalent patients were cluster randomized to DD, trained hospital dietitian (THD), and existing practice (EP) groups. During Phase I (6 months), DD (n?=?116) received intensive education by DD trained on renal nutrition, THD (n?=?299) received care from trained hospital dietitians, and EP (n?=?130) received usual care from untrained hospital dietitians. Patients were followed-up during Phase II (6 months).Results: At baseline, EP had the lowest weekly hemodialysis time, and DD had the highest serum phosphorus and malnutrition-inflammation score. The additional costs of the intervention were low compared with the societal costs (DD: $76.7, $21,007.7; EP: $4.6, $18,675.4; THD: $17.4, $20,078.6, respectively). Between Phases I and II, DD showed the greatest decline in services use and societal costs (DD: –$2,364.0; EP: –$1,727.7; THD: –$1,105.7). At endline, DD experienced the highest decrease in adjusted serum phosphorus (DD: –0.32; EP: +0.16; THD: +0.04?mg/dL), no difference in quality-adjusted life-years (QALY), and the highest societal costs. DD had a cost-effectiveness ratio of $7,853.6 per 1?mg decrease in phosphorus, compared with EP; and was dominated by THD. Regarding QALY, DD was dominated by EP and THD. The results were sensitive to changes in key parameters.Limitations: The analysis depended on numerous assumptions. Interpreting the results is limited by the significant baseline differences in key parameters, suggestive of higher baseline societal costs in DD.Conclusions: DD yielded the greatest effectiveness and decrease in societal costs, but did not affect QALY. Regarding serum phosphorus, DD was likely to be cost-effective compared with EP, but had a low cost-effectiveness probability compared with THD. Regarding QALY, DD was not likely to be cost-effective. Assessing the long-term cost-effectiveness of DD, on similar groups, is recommended. 相似文献
998.
999.
Fenne M. Pinkster 《International journal of urban and regional research》2014,38(6):2042-2059
One of the key challenges in the study of neighbourhood effects on work is to understand the pathways through which disadvantaged neighbourhoods impact the employment opportunities of residents. Endogenous explanations for neighbourhood effects focus on social life in these neighbourhoods, identifying mechanisms of social isolation, deviant work ethics and neighbourhood disorder. This article studies these mechanisms in a low‐income neighbourhood in the Netherlands. The case study shows that unfavourable socioeconomic outcomes can be indirect and unintended consequences of actions and choices in everyday life that are not directly concerned with work. Nevertheless, these individual actions and choices reflect local social practices that are influenced by the marginalized context in which residents lead their lives. 相似文献
1000.