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101.
What is the irrigation potential for Africa? A combined biophysical and socioeconomic approach 总被引:2,自引:0,他引:2
Liangzhi You Claudia Ringler Ulrike Wood-Sichra Richard Robertson Stanley Wood Tingju Zhu Gerald Nelson Zhe Guo Yan Sun 《Food Policy》2011,36(6):770-782
Although irrigation in Africa has the potential to boost agricultural productivities by at least 50%, food production on the continent is almost entirely rainfed. The area equipped for irrigation, currently slightly more than 13 million hectares, makes up just 6% of the total cultivated area. More than 70% of Africa’s poor live in rural areas and mostly depend on agriculture for their livelihoods. As a result, agricultural development is key to ending poverty on the continent. Many development organizations have recently proposed to significantly increase investments in irrigation in the region. However, the potential for irrigation investments in Africa is highly dependent upon geographic, hydrologic, agronomic, and economic factors that need to be taken into account when assessing the long-term viability and sustainability of planned projects. This paper analyzes the large, dam-based and small-scale irrigation investment potential in Africa based on agronomic, hydrologic, and economic factors. We find significant profitable irrigation potential for both small-scale and large-scale systems. This type of regional analysis can guide distribution of investment funds across countries and should be a first step prior to in-depth country- and local-level assessment of irrigation potential, which will be important to agricultural and economic development in Africa. 相似文献
102.
Many phenomena in the life sciences can be analyzed by using a fixed design regression model with a regression function m that exhibits a crossing‐point in the following sense: the regression function runs below or above its mean level, respectively, according as the input variable lies to the left or to the right of that crossing‐point, or vice versa. We propose a non‐parametric estimator and show weak and strong consistency as long as the crossing‐point is unique. It is defined as maximizing point arg max of a certain marked empirical process. For testing the hypothesis H0 that the regression function m actually is constant (no crossing‐point), a decision rule is designed for the specific alternative H1 that m possesses a crossing‐point. The pertaining test‐statistic is the ratio max/argmax of the maximum value and the maximizing point of the marked empirical process. Under the hypothesis the ratio converges in distribution to the corresponding ratio of a reflected Brownian bridge, for which we derive the distribution function. The test is consistent on the whole alternative and superior to the corresponding Kolmogorov–Smirnov test, which is based only on the maximal value max. Some practical examples of possible applications are given where a certain study about dental phobia is discussed in more detail. 相似文献
103.
Community-based natural resource management and nature-based tourism often go hand in hand to drive conservation and economic development in sub-Saharan Africa. However, the complementarity of the two strategies is controversially discussed in the literature. Built on survey data from 200 households conducted in 2012 we analysed the trade-off between conservation and development objectives by means of a mathematical programming model representing the economy of a rural conservancy in Namibia. We found that in the scenario describing unrestricted resource extraction, local communities mainly benefit from fishing and utilising forest products. In comparison, the scenario representing the social optimum, implying sustainably managed fish stocks and appropriate diets for community inhabitants, shows that community households increase agricultural diversification and shift livelihoods towards tourism employment. 相似文献
104.
Alfredo Valentino Matteo Caroli Ulrike Mayrhofer 《International Business Review》2018,27(6):1250-1258
This research examines the effects of the establishment mode of foreign subsidiaries (greenfield vs acquisition) on the type of network relationships (social vs business) they develop in local markets. The authors use the network approach to better understand the role played by local subsidiaries for the development of networks in multinational enterprises. The empirical study is based on a dataset covering 120 foreign-owned subsidiaries in Italy. The findings show that acquired subsidiaries are more directly involved in business relationships, whereas greenfield subsidiaries pay more attention to social relationships before building business networks. The establishment mode thus affects the type of network relationships developed by local subsidiaries, which can help them to overcome the liabilities of foreignness and outsidership. 相似文献
105.
Ulrike Schaede 《Review of International Economics》2004,12(2):277-294
Japan's steep postwar growth was nested in a political economy built around producer‐oriented policies: by fostering the growth of large firms using the tools of industrial policy, the government could jumpstart development. Many large firms, and their employees, benefited indirectly from this growth program, and very small firms and industries not included in the growth model were compensated through preferential policies or subsidies. Japan's social contract evolved around this system, having as its centerpiece lifetime employment. The government spent more resources on supporting exporting industries and compensating domestic ones than on building a forward‐looking welfare system. Japan's decade‐long economic downturn marks a structural transition towards a postindustrial society. While excelling in producing tangibles, Japan has fallen behind in fostering modern industries, including services; the country also lacks a welfare system to handle increasing structural unemployment that this transition brings about. Without a commitment towards a welfare system and a welfare society, and a reorientation of the social contract towards citizens, Japan is unlikely to transition successfully. 相似文献
106.
Otwin Becker Johannes Leitner Ulrike Leopold-Wildburger 《The German Economic Review》2008,9(1):96-112
Abstract. Experimental studies of expectation formation of subjects are predominantly limited to the prediction of one single time series despite the practical relevance of expectations in situations with multiple sources of information. In this paper, we report on an experiment in which subjects are given time series (indicators) as additional information for the judgemental forecast of a stationary time series. The quality and the number of these indicators are varied in three versions of a forecasting experiment. We explore the effects on forecasting accuracy and we test the average forecasts of the subjects for consistency with the rational expectations hypothesis. A simple heuristic is presented that explains the average forecasting behavior better than the rational expectations if indicators are presented to the subjects. It is demonstrated by a simulation study that this result is representative for the considered stationary stochastic processes. 相似文献
107.
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109.
While research has started to pay attention to the content and delivery of sustainable tourism education, little is known about what students actually know and feel with respect to sustainability. This preliminary study explores students’ knowledge of and attitudes toward sustainable tourism as well as their sense of competence and empowerment to make sustainability-related decisions. The focus was on Latin America, where tourism has caused severe negative impacts and where sustainability knowledge and skills are most needed to protect fragile natural and cultural resources. Results show that although most tourism students think sustainable tourism is important, they have limited knowledge of sustainability principles and technical aspects related to sustainable tourism. Implications for teaching are discussed. 相似文献
110.