全文获取类型
收费全文 | 24309篇 |
免费 | 1364篇 |
国内免费 | 480篇 |
专业分类
财政金融 | 2421篇 |
工业经济 | 1230篇 |
计划管理 | 5538篇 |
经济学 | 5050篇 |
综合类 | 2528篇 |
运输经济 | 369篇 |
旅游经济 | 548篇 |
贸易经济 | 3184篇 |
农业经济 | 2390篇 |
经济概况 | 2895篇 |
出版年
2024年 | 66篇 |
2023年 | 561篇 |
2022年 | 543篇 |
2021年 | 818篇 |
2020年 | 1046篇 |
2019年 | 792篇 |
2018年 | 745篇 |
2017年 | 1001篇 |
2016年 | 934篇 |
2015年 | 896篇 |
2014年 | 1764篇 |
2013年 | 2206篇 |
2012年 | 1955篇 |
2011年 | 2225篇 |
2010年 | 1620篇 |
2009年 | 1501篇 |
2008年 | 1576篇 |
2007年 | 1400篇 |
2006年 | 1195篇 |
2005年 | 946篇 |
2004年 | 627篇 |
2003年 | 429篇 |
2002年 | 279篇 |
2001年 | 239篇 |
2000年 | 176篇 |
1999年 | 117篇 |
1998年 | 95篇 |
1997年 | 71篇 |
1996年 | 65篇 |
1995年 | 53篇 |
1994年 | 46篇 |
1993年 | 25篇 |
1992年 | 41篇 |
1991年 | 16篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 11篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The impact of conservation tillage on maize yield and input demand: the case of smallholder farmers in north‐west Ethiopia 下载免费PDF全文
Yohannis Mulu Tessema John Asafu‐Adjaye Bekele Shiferaw 《The Australian journal of agricultural and resource economics》2018,62(4):636-653
This study analyses the economics of conservation tillage (CT) with respect to its effect on maize yield and chemical fertiliser, herbicide, and female and male labour demand. We estimate production and input demand functions using seemingly unrelated regressions on plot‐level cross‐sectional farm household data collected in the north‐west of Ethiopia. A two‐step control function is applied to address potential endogeneity bias due to the inclusion of the CT adoption decision as an explanatory variable. Our results show that CT increases maize yield and chemical fertiliser demand. Additionally, the results show that the adoption of CT reduces female and male labour required for crop production. However, this is achieved through the increased use of herbicides, which might have an undesirable health and environmental effects. 相似文献
72.
空气质量指数(AQI)在波动中既具有整体的时间序列线性特征和明显的季节性波动周期,又具有多种因素影响的不确定性,为了提高AQI的预测精度,基于Ri386 3.3.3和Matlab R2014a两种编程软件,提出了一种同时具有线性和非线性的复合特征的时间序列预测模型——SARIMA-SVR组合模型。以太原市2014年1月—2019年7月的AQI月均值数据为基础,利用SARIMA时间序列模型进行线性预测,利用SVR模型对残差进行非线性预测,加和得到组合预测模型的预测结果,分析比较SARIMA,SVR和SARIMA-SVR这3种模型的预测结果和平均绝对百分比误差。结果表明,组合预测模型发挥了2种模型各自的优势,相较于单一预测模型的预测结果而言,其预测精度更高,稳定性更好。通过此模型得到的空气质量预测结果不仅可为人们的日常生活提供指导,而且可为大气污染的防治工作提供科学依据和借鉴意义。 相似文献
73.
Marco Realdon 《Quantitative Finance》2019,19(2):191-210
Prior literature indicates that quadratic models and the Black–Karasinski model are very promising for CDS pricing. This paper extends these models and the Black [J. Finance 1995, 50, 1371–1376] model for pricing sovereign CDS’s. For all 10 sovereigns in the sample quadratic models best fit CDS spreads in-sample, and a four factor quadratic model can account for the joint effects on CDS spreads of default risk, default loss risk and liquidity risk with no restriction to factors correlation. Liquidity risk appears to affect sovereign CDS spreads. However, quadratic models tend to over-fit some CDS maturities at the expense of other maturities, while the BK model is particularly immune from this tendency. The Black model seems preferable because its out-of-sample performance in the time series dimension is the best. 相似文献
74.
对建筑企业进行环境行为效率评价是促进我国建筑行业健康可持续发展的重要手段。根据建筑行业特点及我国现有的企业环境信用标准,构建了建筑企业环境行为评价的投入产出指标体系,将改进的数据包络分析方法模型运用到企业环境行为效率评价领域,解决了现有企业评价研究主观性突出的问题,得出建筑企业评价分析方法。在此基础上对某代表性建筑企业2010—2017年环境行为数据进行了评价分析。分析结果表明该企业环境行为总体效率良好,但鉴于出现了奇数年和偶数年的效率波动情况,仍需提高环境行为效率。 相似文献
75.
Francesco Pauli 《Revue internationale de statistique》2019,87(1):68-79
The reproducibility crisis, that is, the fact that many scientific results are difficult to replicate, pointing to their unreliability or falsehood, is a hot topic in the recent scientific literature, and statistical methodologies, testing procedures and p‐values, in particular, are at the centre of the debate. Assessment of the extent of the problem–the reproducibility rate or the false discovery rate–and the role of contributing factors are still an open problem. Replication experiments, that is, systematic replications of existing results, may offer relevant information on these issues. We propose a statistical model to deal with such information, in particular to estimate the reproducibility rate and the effect of some study characteristics on its reliability. We analyse data from a recent replication experiment in psychology finding a reproducibility rate broadly coherent with other assessments from the same experiment. Our results also confirm the expected role of some contributing factor (unexpectedness of the result and room for bias) while they suggest that the similarity between original study and the replica is not so relevant, thus mitigating some criticism directed to replication experiments. 相似文献
76.
Jung Eun Lee 《心理学和销售学》2019,36(1):57-71
Retailers frequently use exaggerated price discount advertisements with a tensile price claim (TPC; e.g., “Save up to 70%”) to attract consumers because they expect that once consumers enter a store, they will purchase low‐ or medium‐discounted products. Drawing on the selective accessibility model, this study investigated the way in which an implausibly high maximum level of savings stated in a TPC influences consumers’ expected price discount (EPD) and perceptions of actual price discounts across different types of TPCs (i.e., TPC stating a maximum level and TPC stating a range of savings). This study also investigated two situations in which consumers have previous knowledge of a product’s price discount versus when they have less or no knowledge of the discount. For both conditions, a single‐anchor TPC (i.e., “Save up to Y%”) that stated an implausible maximum level of savings led to a higher EPD and lower perceptions of the deal (i.e., perceived savings, price fairness, and perceived value) with respect to the actual price discount than did a TPC with a plausible maximum level of savings. In contrast, when the TPC stated two anchors (i.e., “Save X–Y%”) and consumers had knowledge of the price discount, their EPDs assimilated only toward the plausible anchor (X), and ignored the implausibly high maximum price discount (Y), resulting in a lower EPD and higher perceptions of the deal of the actual price discounts than a TPC that stated a plausibly high maximum level of savings. In contrast, when consumers had no knowledge of the price discount, their EPDs only adjusted toward the more plausible anchor (X), regardless of whether they perceived the maximum anchor as plausible or implausible. Thus, there was no difference in consumers’ perceptions of “Save X–Y%” between implausibly and plausibly high Y%. 相似文献
77.
Trade openness is an important determinant of the inflation process. The effect of trade openness on inflation, however, is still an issue of debate at both theoretical and empirical levels. This study tried to provide a contribution to the literature by examining the relationship between inflation and trade openness in Tunisia over the period 1975Q1-2015Q4 using a nonlinear model. The originality of this study stems from the fact that it is the first investigation considering both the Residual-Based Tests for Cointegration in Models with the Regime Shifts and Threshold Regression model. The linear model confirms the existence of a positive relationship between inflation and trade in Tunisia. Yet, considering the nonlinear model, trade openness growth and Consumer Price Index (CPI) inflation growth show a statistically significant negative link as long as the trade openness evolution does not exceed the threshold. Nevertheless, if the trade openness growth is higher than the threshold, integrating the trade positively affects CPI inflation. Furthermore, a positive influence of Money supply growth on this type of inflation was noticed in Tunisia in all the considered regimes proving the effect of monetary factors on inflation level. Consequently, trade openness could be used to control inflation in Tunisia. 相似文献
78.
由于即将退休与刚退休的这一代人拥有低赡养比与低抚养比,本文称其为“双低一代”。本文基于宏观统计数据与微观调查数据,利用分位回归等方法对“双低一代”的社会学特征与经济学特征进行研究,发现其具有人口总量较多、教育背景优良、社会阅历丰富、消费倾向明显等特征。此外,通过对“双低一代”的人力资本存量进行测算,提出充分发挥“双低一代”余热、缓解老龄化问题的政策建议。 相似文献
79.
Binlei Gong 《新兴市场金融与贸易》2018,54(15):3438-3453
The “industry nurturing agriculture” reforms and World Trade Organization accession led to dramatic growth in public expenditure and international trade in China’s agricultural sector. This article aims to estimate the effects of public expenditure and trade on agricultural productivity in China for 2004–2015. A semi-parametric production function with shape constraints is introduced to derive more accurate productivity before the productivity determinants are analyzed with an emphasis on public expenditure and trade. The empirical result shows that public expenditure and exports can effectively improve agricultural productivity, while imports have no significant effects. Policy implications are discussed in the context of supply-side reforms. 相似文献
80.