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1.
吉林省地区间经济力差距分析   总被引:1,自引:1,他引:0  
按照Kuznets倒U字假说,我国实现经济高速增长过程中,由于区域经济增长的不平衡性,导致了地区间经济力差距的扩大。吉林省为了尽可能地缩小地区间经济力的差距,以便促进地区的均衡发展,应该在省内形成以信息和高速公路网络为基础的共同市场。  相似文献   
2.
Annual concentrations of toxic air contaminants are of primary concern from the perspective of chronic human exposure assessment and risk analysis. Despite recent advances in air quality monitoring technology, resource and technical constraints often impose limitations on the availability of a sufficient number of ambient concentration measurements for performing environmental risk analysis. Therefore, sample size limitations, representativeness of data, and uncertainties in the estimated annual mean concentration must be examined before performing quantitative risk analysis. In this paper, we discuss several factors that need to be considered in designing field-sampling programs for toxic air contaminants and in verifying compliance with environmental regulations. Specifically, we examine the behavior of SO2, TSP, and CO data as surrogates for toxic air contaminants and as examples of point source, area source, and line source-dominated pollutants, respectively, from the standpoint of sampling design. We demonstrate the use of bootstrap resampling method and normal theory in estimating the annual mean concentration and its 95% confidence bounds from limited sampling data, and illustrate the application of operating characteristic (OC) curves to determine optimum sample size and other sampling strategies. We also outline a statistical procedure, based on a one-sided t-test, that utilizes the sampled concentration data for evaluating whether a sampling site is compliance with relevant ambient guideline concentrations for toxic air contaminants.  相似文献   
3.
The weaknesses of established model selection procedures based on hypothesis testing and similar criteria are discussed and an alternative based on synthetic (composite) estimation is proposed. It is developed for the problem of prediction in ordinary regression and its properties are explored by simulations for the simple regression. Extensions to a general setting are described and an example with multiple regression is analysed. Arguments are presented against using a selected model for any inferences.  相似文献   
4.
This study examines the relationships among personal coping resources, social support, external coping resources, job stressors and job strains in a sample of 110 American Telephone and Telegraph employees undergoing a major organizational restructuring. The study expanded on a model suggested by Ashford (1988) by defining another category of coping resources that employees may draw upon to deal with the stressors and strains which occur during major organizational changes. External coping resources were defined as those which provided employees with a sense of 'vicarious control' in stressful situations. Results indicated that personal coping resources, social support and external coping resources had a direct effect upon job stressor and strain levels. No 'buffering' effect of these coplng resources was found. Hierarchical regression analyses indicated that external coping resources added to the prediction of job stressors and strains even when pertonal coping resources and social support were entered first into the prediction questions.  相似文献   
5.
金融危机近些年爆发频繁,传统市场理论如有效市场假说和行为金融面对复杂的现实金融世界未能给出合理解释.Lo提出的适应性市场假说则弥合了这两个学派的分歧,逐渐引起了学术界的重视.本文尝试从动态市场效率、时变贝塔和技术交易策略演变这三个角度对适应性市场假说能否解释我国资本市场进行实证研究.研究发现:我国股票市场效率在动态变化,无效的时段与金融危机或政策巨变等重大事件联系密切;股市风格指数贝塔随市场环境变化而改变;技术交易策略绩效随投资者适应环境变化而演变.研究结果表明,适应性市场假说相比有效市场假说和经典资本资产定价模型,能够更好地解释我国资本市场上述现象.最后对投资者如何根据市场环境变化制定适应性投资策略给出几点建议.  相似文献   
6.
《Risk analysis》2018,38(1):194-209
This article presents the findings from a numerical simulation study that was conducted to evaluate the performance of alternative statistical analysis methods for background screening assessments when data sets are generated with incremental sampling methods (ISMs). A wide range of background and site conditions are represented in order to test different ISM sampling designs. Both hypothesis tests and upper tolerance limit (UTL) screening methods were implemented following U.S. Environmental Protection Agency (USEPA) guidance for specifying error rates. The simulations show that hypothesis testing using two‐sample t ‐tests can meet standard performance criteria under a wide range of conditions, even with relatively small sample sizes. Key factors that affect the performance include unequal population variances and small absolute differences in population means. UTL methods are generally not recommended due to conceptual limitations in the technique when applied to ISM data sets from single decision units and due to insufficient power given standard statistical sample sizes from ISM.  相似文献   
7.
We present an evolutionary perspective on charismatic leadership, arguing that charisma has evolved as a credible signal of a person's ability to solve a coordination challenge requiring urgent collective action from group members. We suggest that a better understanding of charisma's evolutionary and biological origins and functions can provide a broader perspective in which to situate current debates surrounding the utility and validity of charismatic leadership as a construct in the social sciences. We outline several key challenges which have shaped our followership psychology, and argue that the benefits of successful coordination in ancestral environments has led to the evolution of context-dependent psychological mechanisms which are especially attuned to cues and signals of outstanding personal leadership qualities. We elaborate on several implications of this signaling hypothesis of charismatic leadership, including opportunities for deception (dishonest signaling) and for large-scale coordination.  相似文献   
8.
在中印共同崛起的大背景下,探究印度对中国崛起的认知尤为必要。通过皮尤"全球态度调查"项目的数据可见印度对中国崛起的认知呈现"负面"态势。究其原因,在个人层面,印度公众对中国的无知与冷漠以及某些媒体记者对中国的歪曲报道直接造成这一结果;在国家层面,中印之间在边界争端、西藏问题、中印巴和中美印这四个关键议题上存在分歧,而这些敏感的议题又通过媒体的肆意渲染而影响印度公众对中国崛起的认知;印度公众对中国崛起的认知源于中印之间存在的"安全困境"。  相似文献   
9.
中国股市是一个高风险的股市 ,因此有必要运用现代金融计算技术和计量金融理论建立一套股市预警系统。本文在讨论了建立股市预警系统的必要性、可行性的基础上 ,着重讨论了股市预警系统的指标构成原则和框架 ,将近年来在现代金融理论中发展很快的协整理论(CointegrationTheory)、条件异方差理论、市场有效性理论等引入到股市预警系统框架中来  相似文献   
10.
Software packages usually report the results of statistical tests using p-values. Users often interpret these values by comparing them with standard thresholds, for example, 0.1, 1, and 5%, which is sometimes reinforced by a star rating (***, **, and *, respectively). We consider an arbitrary statistical test whose p-value p is not available explicitly, but can be approximated by Monte Carlo samples, for example, by bootstrap or permutation tests. The standard implementation of such tests usually draws a fixed number of samples to approximate p. However, the probability that the exact and the approximated p-value lie on different sides of a threshold (the resampling risk) can be high, particularly for p-values close to a threshold. We present a method to overcome this. We consider a finite set of user-specified intervals that cover [0, 1] and that can be overlapping. We call these p-value buckets. We present algorithms that, with arbitrarily high probability, return a p-value bucket containing p. We prove that for both a bounded resampling risk and a finite runtime, overlapping buckets need to be employed, and that our methods both bound the resampling risk and guarantee a finite runtime for such overlapping buckets. To interpret decisions with overlapping buckets, we propose an extension of the star rating system. We demonstrate that our methods are suitable for use in standard software, including for low p-value thresholds occurring in multiple testing settings, and that they can be computationally more efficient than standard implementations.  相似文献   
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