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1.
林科军 《中国农业资源与区划》2018,39(6):128-135
[目的]通过分析2012年和2014年乌蒙山片区绿色减贫指数,评价该地区不同年份扶贫效果,这也为今后各项扶贫政策的实施提供理论参考。[方法]文章依据中国绿色减贫指数指标体系,从经济增长绿化度、资源利用与环境保护程度、社会发展能力和扶贫开发与减贫效果4个方面,以人均地区生产总值、单位地区生产总值能耗等27个因子作为评价指标,利用线性加权综合法分析2012年和2014年经济增长绿化度、资源利用与环境保护程度、社会发展能力和扶贫开发与减贫效果指标值,最终确定绿色减贫指数。同时,分析片区内各贫困县波动较大的第三产业增加值比重、单位耕地面积化肥施用量、城乡收入比和农村人均纯收入增长率等指标。[结果]2014年相比2012年,乌蒙山片区经济增长绿化度、资源利用与环境保护程度和扶贫开发与减贫效果指标值上升,社会发展能力指标值降低,绿色减贫指数提高了15.40%。各县第三产业比重均降低,但农村人均纯收入都有提高。四川省10个县单位耕地面积化肥施用量增加。四川省除叙永县和美姑县,贵州省除赤水市,片区内的各贫困县城乡收入比降低。[结论]2014年,乌蒙山区在落实国家扶贫规划上取得了较好的成效。但各县之间差距较大,在今后的扶贫攻坚中,需要从不同地区的实际情况出发,了解贫困类型和贫困程度,考察当地资源储备和环境现状,统筹区域发展。 相似文献
2.
José García-Pérez María del Mar López-Martín Catalina García-García Román Salmerón-Gómez 《Revue internationale de statistique》2020,88(3):776-792
Justifying ridge regression from a geometrical perspective is one of the main contributions of this paper. To the best of our knowledge, this question has not been treated previously. This paper shows that ridge regression is a particular case of raising procedures that provide greater flexibility by transforming the matrix X associated with the model. Thus, raising procedures, based on a geometrical idea of the vectorial space associated with the columns of matrix X , lead naturally to ridge regression and justify the presence of the well-known constant k on the main diagonal of matrix X ′ X . This paper also analyses and compares different alternatives to raising with respect to collinearity mitigation. The results are illustrated with an empirical application. 相似文献
3.
针对传统子空间算法需要进行特征值分解或奇异值分解等复杂计算的问题,提出一种双平行线阵(Double Parallel Linear Array,DPLA)的快速一维波达方向(Direction of Arrival,DOA)估计算法。算法通过处理互协方差矩阵的第一列元素构造出等效的噪声子空间,再通过求根MUSIC(Multiple Signal Classification)算法得到DOA估计,有效避开了特征值分解或奇异值分解,降低了计算复杂度,提高了运算速度。仿真结果表明,该算法在提高了估计精度的同时减少了估计时间。 相似文献
4.
Motor carrier safety is an important concern of shippers, carriers, policy makers, consignees, insurance providers, and the motoring public. One aspect of carrier safety that has garnered substantial attention is whether carriers making greater use of owner–operators are more or less safe vis‐à‐vis carriers making greater use of employee drivers. Currently, conflicting theoretical predictions exist regarding the direction of this relationship. In this article, we offer a reconciliation of the alternative theoretical predictions by developing a coherent theory that merges sociological rational choice theory and theory regarding motor carrier safety. We subject our theory to empirical testing by fitting a series of seemingly unrelated regression models to a vector of safety measures tracked as part of the Federal Motor Carrier Safety Administration's Compliance, Safety, and Accountability program. Our results are consistent with our proposed theory of owner—operator safety and provide meaningful theoretical and managerial implications and directions for future research. 相似文献
5.
研究目的:针对以往工业用地集约利用影响因素研究仅考虑单一层次且多集中于宏观、中观尺度的问题,尝试从微观企业尺度分析企业、开发区两层因素对工业用地集约利用的影响。研究方法:综合评价法和分层线性模型。研究结果:江西省开发区企业土地集约利用水平总体偏低,在地域分布上呈现出赣北赣东赣西赣中赣南的特征,与开发区土地集约利用水平地域分布一致;开发区企业用地集约度受到企业和开发区两个层次影响。企业层次主要受企业规模、企业所有制、行业类型、研发投入和初始基础设施影响;开发区层次主要受开发区级别、工业用地率和土地利用集约度影响,并且通过影响企业资本类型、研发投入和初始基础设施的系数对企业用地集约度产生加成效用。研究结论:分层线性模型有效解决了开发区企业土地集约利用影响因素的结构分层和嵌套问题,揭示了开发区企业土地集约利用影响因素与机制,研究结果为研究区有针对性的制定土地集约利用政策提供一定依据。 相似文献
6.
线性文化遗产是一种特殊的遗产类型,随着人们对遗产完整性不断深入的理解以及遗产活化利用理念的发展,线性文化遗产旅游的重要性日益显现。因此,树立线性文化遗产意识,把握线性文化遗产特征,是推进线性文化遗产旅游利用和可持续发展的重要问题。本文以《世界遗产名录》中收录的线性文化遗产为基础数据,对线性文化遗产的类别与列入标准、资源组合模式和核心区与缓冲区等典型特征进行深入分析,并从旅游空间演化和旅游活化路径两方面总结其对旅游利用模式的影响,以期为线性文化遗产旅游的可持续发展提供科学参考。研究结果表明,线性文化遗产旅游空间结构发展过程遵循“增长极”演化规律,并在遗产文化分层上表现出不同的利用方式和活化路径。 相似文献
7.
Existing research on private label market share is primarily in the context of the Western market. The Chinese market context research is scarce, although private labels are developing rapidly in the past several years. This study investigates how the average wage and number of stores affect the Chinese market's private label market share. More importantly, this paper examines the moderating effect of the average wage and the number of stores on the relationship between the private label market share and product assortment as well as the relationship between the private label market share and pricing. Data collected from a Chinese supply chain dyad is analyzed to study category management using hierarchical linear models. The results reveal that the average wage and the number of stores positively affect the private label market share. Furthermore, the average wage enhances the negative effect of the number of brands, weakens the negative effect of the private label price, weakens the positive effect of national brand price. Meanwhile, the number of stores enhances the positive effect of the SKU proliferation of private label, enhances the negative effects of the number of brands, and enhances the negative effect of the private label price. This study contributes to category management. Furthermore, the findings will be valuable to domestic and international grocery marketers and retailers operating private labels in China. 相似文献
8.
This study uses multiple linear regression to identify factors contributing to perceived risk among residents near Taoyuan and Kaohsiung International Airports, the effect of perceived risk on their willingness to reduce risk, and consumption preferences that can reduce risk. Results indicated that residents' risk perception near Taoyuan Airport is lower than that near Kaohsiung Airport. Noise pollution experience, perceived probability of environmental contamination and negative effects, and perceived severity of catastrophic consequences significantly increase residents' perceived risks. Residents are willing to recognize and participate in mitigating the risks of aircraft noise pollution. The more risk residents perceive, the more willing they are to participate in disaster reduction and investigate means of improving the risk environment. 相似文献
9.
《Socio》2019
Biofuels are emerging as a prominent renewable and sustainable energy sources in developed countries. In this sense, this paper presents a case study in which a biorefinery has to be sited in Northern Spain. Thus, the strategic decision of locating such a facility is deeply investigated through strategic policy evaluation. Then, tactical decisions ranging from purchasing and transportation policies to storage protocols are carried out. Only local and limited biomass can be harvested for supplying the biorefinery through a heterogeneous vehicle fleet. Moreover two different and mutually exclusive storage strategies are evaluated: direct supply from crops to biorefinery and using intermediate-collectors. Additionally, crop exploitation factors and biorefinery sizes are used to generate several scenarios in which the strategic decision of location as well as all the tactic decisions are made. Some mixed integer linear programming models are proposed to figure out all relevant decision problems.The results suggest that the Northwest study area as the best option to locate the biorefinery and recommend the intermediate-collector storage strategy. Moreover, the key information about critical biomass, crops and times are also provided. 相似文献
10.
[目的]以高分1号(GF-1)融合2m卫星遥感影像为基础数据源,结合土地利用现状数据、高分多源遥感影像和地面样方等数据,对冬小麦分类提取中存在的面积误差问题进行研究和分析。[方法]文章以河南省永城市为研究区,在冬小麦提取结果聚类处理基础上,基于线性地物缓冲区数据,采用GIS空间运算实现线性地物面积扣除,接着分析了样方数据和土地利用现状数据再扣除零星地物面积比例上的差异,并采用样方零星地物平均扣除系数对全市各乡镇耕地与非耕地中冬小麦提取面积进行了相关统计和误差分析。[结果]永城市冬小麦最终解译面积11. 29万hm~2,其中线性地物和零星地物扣除面积分别为6 613. 08hm~2和3 875. 22hm~2,占研究区冬小麦解译面积的5. 86%和3. 32%,与统计上报数据相比,其处理前后误差由14. 12%降低至4. 41%,有效地提高冬小麦提取面积精度。[结论]误差来源分析与修正对冬小麦解译面积核算精度具有重要影响,该研究为县级区域尺度下冬小麦面积提取核算提供了思路和借鉴。 相似文献