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21.
The problem considered is that of finding an optimum measurement schedule to estimate population parameters in a nonlinear model when the patient effects are random. The paper presents examples of the use of sensitivity functions, derived from the General Equivalence Theorem for D-optimality, in the construction of optimum population designs for such schedules. With independent observations, the theorem applies to the potential inclusion of a single observation. However, in population designs the observations are correlated and the theorem applies to the inclusion of an additional measurement schedule. In one example, three groups of patients of differing size are subject to distinct schedules. Numerical, as opposed to analytical, calculation of the sensitivity function is advocated. The required covariances of the observations are found by simulation. 相似文献
22.
在对国外公司财务预警经典研究成果进行回顾和总结的基础上,运用多元判别分析方法(MDA)和逐步判别分析(Stepdisc)等方法逐层推进构造预测模型,以经济实用为选择标准,最终建立一个预测准确率最高、变量最少的适合中国实际情况的财务危机预测模型。 相似文献
23.
针对串联型稳压器,设计了一种应用于串联型稳压器具有自建基准的新型误差放大电路。该电路具有构思巧妙,结构优化,易于集成及较高的开环增益,共模抑制比及交流特性的优点。通过验证,实测数据与仿真结果基本一致。 相似文献
24.
杨曼英 《湖南人文科技学院学报》2004,(2):78-79
通过定义、定理、正反对比的例题论述了函数列收敛、一致收敛、内闭一致收敛及其之间的关系与差异。 相似文献
25.
Peter Hall Qiwei Yao 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(2):425-442
Summary. We develop a general methodology for tilting time series data. Attention is focused on a large class of regression problems, where errors are expressed through autoregressive processes. The class has a range of important applications and in the context of our work may be used to illustrate the application of tilting methods to interval estimation in regression, robust statistical inference and estimation subject to constraints. The method can be viewed as 'empirical likelihood with nuisance parameters'. 相似文献
26.
屈颖 《西安石油大学学报(社会科学版)》2003,12(2):43-46
阐述了我国财务公司的性质和特点;指出并分析了当前我国财务公司存在的业务定位不准,融资渠道狭窄,缺乏人才资源和行政干预过多等主要问题;提出了明确财务公司的定位,拓展金融服务功能,拓宽融资渠道,开发人才资源,制定长远发展战略,提高竞争力和抗风险能力等解决问题的对策。 相似文献
27.
Diagnostics for dependence within time series extremes 总被引:1,自引:0,他引:1
Anthony W. Ledford Jonathan A. Tawn 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(2):521-543
Summary. The analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed. 相似文献
28.
郑璋鑫 《宝鸡文理学院学报(社会科学版)》2002,22(1):92-96
西部经济发展落后的重要原因之一在于资金的短缺.要发展西部经济,缩小东西部差距,有必要制定区域(差别)货币金融政策,包括差别再贷款权政策、差别存款准备金率和贴现率政策、差别利率政策以及在西部开发中试行资本项目可兑换政策和积极培育西部资本市场,发展区域金融中心等. 相似文献
29.
Impacts of complex emergencies or relief interventions have often been evaluated by absolute mortality compared to international standardized mortality rates. A better evaluation would be to compare with local baseline mortality of the affected populations. A projection of population-based survival data into time of emergency or intervention based on information from before the emergency may create a local baseline reference. We find a log-transformed Gaussian time series model where standard errors of the estimated rates are included in the variance to have the best forecasting capacity. However, if time-at-risk during the forecasted period is known then forecasting might be done using a Poisson time series model with overdispersion. Whatever, the standard error of the estimated rates must be included in the variance of the model either in an additive form in a Gaussian model or in a multiplicative form by overdispersion in a Poisson model. Data on which the forecasting is based must be modelled carefully concerning not only calendar-time trends but also periods with excessive frequency of events (epidemics) and seasonal variations to eliminate residual autocorrelation and to make a proper reference for comparison, reflecting changes over time during the emergency. Hence, when modelled properly it is possible to predict a reference to an emergency-affected population based on local conditions. We predicted childhood mortality during the war in Guinea-Bissau 1998-1999. We found an increased mortality in the first half-year of the war and a mortality corresponding to the expected one in the last half-year of the war. 相似文献
30.
学术期刊属性研究 总被引:3,自引:0,他引:3
尹玉吉 《山东理工大学学报(社会科学版)》2006,22(2):99-105
在编辑传播学界关于学术期刊属性的研究上,普遍存在着一个突出的问题,这就是论者们几乎不假思索地认为“学术期刊是商品”。我们认为,这是一个很大的误区,这种认识在理论上是错误的,在实践上是有害的。首先,“学术期刊商品论”是自相矛盾的;其次,“学术期刊商品论”与马克思主义经济学是相悖的;再次,“学术期刊商品论”与普遍存在的事实是恰恰相反的。学术期刊和学术事业是一项创新的事业,它关系一个国家的生存安危,对此,江泽民同志曾经反复强调,创新是一个民族进步的灵魂,是国家兴旺发达的不竭动力之源。因此,对待学术和学术期刊事业应当像对待军队、警察机构一样,不能也不可能使其商品化,学术期刊应该走自己的健康发展之路。 相似文献