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991.
This study investigates what pupils aged 10–12 can learn from working with robots, assuming that understanding robotics is a sign of technological literacy. We conducted cognitive and conceptual analysis to develop a frame of reference for determining pupils’ understanding of robotics. Four perspectives were distinguished with increasing sophistication; “psychological”, “technological”, “function”, and “controlled system”. Using Lego® Mindstorms® NXT robots, as an example of a Direct Manipulation Environment, we developed and conducted a lesson plan to investigate pupils’ reasoning patterns. There is ample evidence that pupils have little difficulty in understanding that robots are man-made technological and functional artifacts. Pupils’ understanding of the controlled system concept, more specifically the complex sense-reason-act loop that is characteristic of robotics, can be fostered by means of problem solving tasks. The results are discussed with respect to pupils’ developing technological literacy and the possibilities for teaching and learning in primary education.  相似文献   
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995.
The Emission Trading Schemes of China and Europe show that China’s envisaged national ETS could bring a major contribution in the international approach against global warming; new perspectives on the use of composite sustainability indicators are also highlighted. China’s regional pilot schemes will converge to a (more) uniform price of emission allowances. As China is a major economic and political actor in the world economy, China’s progress with ETS is important. At the same time, China’s progress in the field of green international competitiveness – standing for a positive revealed comparative advantage in environmentally friendly goods – in the period 2000–2015 is considerable and the improved positioning of China in the EIIW-vita sustainability indicator shows considerable technological dynamics in Asia. The European ETS is working, but it suffers from the rather low price of emission allowances. The long-term time horizon of 2050 in the EU climate policy is rather ambitious and it is unclear whether or not a consistent G20 approach can be achieved – with the EU, China, Japan and the US cooperating amongst each other. There is a lack of a specialized climate stabilization institution in the world economy, the traditional anchoring of climate policy in the UN weakens the practical pressure for efficient cooperation since the UN is very heterogeneous in terms of per capita income and GHG emissions per unit of GDP; G20 might be an institution that is suitable for effective policy cooperation. More initiatives in the field of recycling could be useful.  相似文献   
996.
Effects of direct flights on trade costs are investigated using micro price data at the city level. After controlling for local retail/distribution costs, traded input prices are obtained to be further used in the measurement of trade costs across cities through arbitrage conditions. The existence of a direct flight enters trade costs regressions negatively and significantly. The results are shown to be robust to the consideration of many control variables, nonlinearities in the effects of distance on trade costs, possible endogeneity of having direct flights between cities and alternative definitions of the data. The direct flights that are shown to be determined by bilateral air services agreements are further shown to reduce trade costs through an endogeneity analysis; the main policy implications are twofold: (i) international trade policies through aviation services, such as Open Skies Agreements of the US, are alternative trade policy tools to reduce international trade barriers; (ii) direct flights facilitate the integration of internal markets as in the case of European Union.  相似文献   
997.
Theoretically, reallocating an input from a firm where the input has low marginal product to a firm where the input has high marginal product would increase aggregate productivity without any underlying change in technology. This paper argues that measuring these reallocation effects requires accounting for detailed input types because, for example, differences in wages across producers often reflect the skill mix of workers, not allocative inefficiency. The paper develops an approach to measuring reallocation that accounts for worker skill and the composition of capital assets, thus focuses on the set of countries for which this information is available. The results show once input heterogeneity is accounted for, the effects of reallocation on aggregate productivity were small on average, but sizable in a subset of countries. Panel regressions indicate that reallocation effects are related to population distribution and government effectiveness.  相似文献   
998.
This paper focuses on developing countries’ pioneer exports to the OECD and obtains several important results on export dynamics, linking export experience and export survival. Using product level data at the SITC 5-digit level for 114 developing countries over the 1962–2009 period, we show that prior export experience obtained in non-OECD markets significantly increases survival of pioneer exports toward the OECD. The experience does not need to last long, as gaining experience for more than two years does not confer any additional benefit. The effect of experience depreciates rapidly with time: a break in export experience prior to entering the OECD reduces the advantage on survival. Finally, the role of prior export experience is particularly relevant for survival in the first two years upon entry into the OECD. The geographic dynamic of export experience reveals that experience is acquired in neighboring, easy to access markets before reaching more distant, richer partners and ultimately serving the OECD with a higher probability of survival.  相似文献   
999.
In this paper, we examine optimal exchange-rate flexibility in a model of local-currency pricing with vertical production and trade. Following a large body of empirical evidence, we assume that final-goods prices are sticky, but intermediate-goods prices are flexible. We find that, unlike what is found in the literature, optimal nominal exchange rate is flexible under local-currency pricing. The key element in deriving our conclusion is the difference in expenditure shares between home and foreign households. The conclusion holds even if the degrees of home bias in production are identical between home and foreign final-goods producers, which contrasts with the findings in the literature.  相似文献   
1000.
In this paper I analyze the London Monetary and Economic Conference of 1933, an almost forgotten episode in U.S. monetary history. I study how the Conference shaped dollar policy during the second half of 1933 and early 1934. I use daily data to investigate the way in which the Conference and related policies associated to the gold standard affected commodity prices, bond prices, and the stock market. My results show that the Conference itself did not impact commodity prices or the stock market. However, it had a small effect on bond prices. I do find that the events associated with the abandonment of the gold standard impacted prices in a significant way, even before the actual monetary and currency channels were at work. These results are consistent with the “change in regime” hypothesis of Sargent (1983).  相似文献   
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