全文获取类型
收费全文 | 4476篇 |
免费 | 167篇 |
国内免费 | 52篇 |
专业分类
管理学 | 258篇 |
劳动科学 | 18篇 |
民族学 | 168篇 |
人才学 | 2篇 |
人口学 | 120篇 |
丛书文集 | 1193篇 |
理论方法论 | 188篇 |
综合类 | 2025篇 |
社会学 | 304篇 |
统计学 | 419篇 |
出版年
2024年 | 4篇 |
2023年 | 15篇 |
2022年 | 41篇 |
2021年 | 55篇 |
2020年 | 56篇 |
2019年 | 54篇 |
2018年 | 76篇 |
2017年 | 121篇 |
2016年 | 79篇 |
2015年 | 120篇 |
2014年 | 160篇 |
2013年 | 272篇 |
2012年 | 255篇 |
2011年 | 294篇 |
2010年 | 363篇 |
2009年 | 325篇 |
2008年 | 290篇 |
2007年 | 334篇 |
2006年 | 345篇 |
2005年 | 313篇 |
2004年 | 153篇 |
2003年 | 117篇 |
2002年 | 152篇 |
2001年 | 126篇 |
2000年 | 86篇 |
1999年 | 88篇 |
1998年 | 60篇 |
1997年 | 62篇 |
1996年 | 50篇 |
1995年 | 61篇 |
1994年 | 44篇 |
1993年 | 39篇 |
1992年 | 21篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有4695条查询结果,搜索用时 0 毫秒
71.
Yanjie Zhang Bilal M. Ayyub Dongming Zhang Hongwei Huang Yalda Saadat 《Risk analysis》2019,39(12):2718-2731
The observed global sea level rise owing to climate change, coupled with the potential increase in extreme storms, requires a reexamination of existing infrastructural planning, construction, and management practices. Storm surge shows the effects of rising sea levels. The recent super storms that hit the United States (e.g., Hurricane Katrina in 2005, Sandy in 2012, Harvey and Maria in 2017) and China (e.g., Typhoon Haiyan in 2010) inflicted serious loss of life and property. Water level rise (WLR) of local coastal areas is a combination of sea level rise, storm surge, precipitation, and local land subsidence. Quantitative assessments of the impact of WLR include scenario identification, consequence assessment, vulnerability and flooding assessment, and risk management using inventory of assets from coastal areas, particularly population centers, to manage flooding risk and to enhance infrastructure resilience of coastal cities. This article discusses the impact of WLR on urban infrastructures with case studies of Washington, DC, and Shanghai. Based on the flooding risk analysis under possible scenarios, the property loss for Washington, DC, was evaluated, and the impact on the metro system of Shanghai was examined. 相似文献
72.
One of the most dynamic and fruitful areas of current health‐related research concerns the various roles of the human microbiome in disease. Evidence is accumulating that interactions between substances in the environment and the microbiome can affect risks of disease, in both beneficial and adverse ways. Although most of the research has concerned the roles of diet and certain pharmaceutical agents, there is increasing interest in the possible roles of environmental chemicals. Chemical risk assessment has, to date, not included consideration of the influence of the microbiome. We suggest that failure to consider the possible roles of the microbiome could lead to significant error in risk assessment results. Our purpose in this commentary is to summarize some of the evidence supporting our hypothesis and to urge the risk assessment community to begin considering and influencing how results from microbiome‐related research could be incorporated into chemical risk assessments. An additional emphasis in our commentary concerns the distinct possibility that research on chemical–microbiome interactions will also reduce some of the significant uncertainties that accompany current risk assessments. Of particular interest is evidence suggesting that the microbiome has an influence on variability in disease risk across populations and (of particular interest to chemical risk) in animal and human responses to chemical exposure. The possible explanatory power of the microbiome regarding sources of variability could reduce what might be the most significant source of uncertainty in chemical risk assessment. 相似文献
73.
In order to broadcast an alert message from the accident site to the control center as soon as possible, the roadside units (RSUs) act as the critical component in vehicular ad hoc networks (VANETs). It is not possible to make a pervasive RSU deployment due to the huge cost and market requirement. Hence, how to deploy a minimum number of RSUs in a given region becomes a challenge problem. In this paper, we present an analysis for the total delay of broadcasting alert messages in VANETs along highways. Based on the analysis, the relationship between optimal number of RSUs with the highway distance is given. Moreover, the experiment results verifies the delay analysis and the optimization of RSUs deployment. 相似文献
74.
We provide an exact myopic analysis for an N‐stage serial inventory system with batch ordering, linear ordering costs, and nonstationary demands under a finite planning horizon. We characterize the optimality conditions of the myopic nested batching newsvendor (NBN) policy and the myopic independent batching newsvendor (IBN) policy, which is a single‐stage approximation. We show that echelon reorder levels under the NBN policy are upper bounds of the counterparts under both the optimal policy and the IBN policy. In particular, we find that the IBN policy has bounded deviations from the optimal policy. We further extend our results to systems with martingale model of forecast evolution (MMFE) and advance demand information. Moreover, we provide a recursive computing procedure and optimality conditions for both heuristics which dramatically reduces computational complexity. We also find that the NBN problem under the MMFE faced by one stage has one more dimension for the forecast demand than the one faced by its downstream stage and that the NBN policy is optimal for systems with advance demand information and stationary problem data. Numerical studies demonstrate that the IBN policy outperforms on average the NBN policy over all tested instances when their optimality conditions are violated. 相似文献
75.
推行人力资本出资形式需研究的几个法律问题 总被引:1,自引:0,他引:1
推行人力资本出资多形式意义非常重大。在制度上需要建构一套完整的体系,这套体系需要包括:人力资本认定要件、人力资本作价方式、人力资本出资范围、人力资本出资比例、人力资本出资转让、人力资本退出机制、人力资本清算程序等内容。人力资本出资形式的研究主要涉及四个方面的法律问题:出资形式的合法性问题、出资额评估方法选择问题、出资法律责任承担问题、出资风险预防问题。 相似文献
76.
业务考评制度与刑事法治 总被引:2,自引:0,他引:2
业务考评制度属法律规则之外的“规则”,在我国特定的司法背景和司法条件下,多年来业务考评制度在刑事司法实践中发挥了不可忽视的作用并仍然可能产生一定的积极影响。但是,业务考评制度存在着大量“前现代”的观念和违反诉讼规律的制度设计,与现代刑事法治的要求不相符合,使司法人员处在“双重结构化”之中,从而产生了一系列负面效应。基于刑事法治的立场,立足于中国现实及社会背景,笔者主张取消法院系统的业务考评制度,彻底改造检察机关和公安机关的业务考评制度。 相似文献
77.
美国历史上的黑白混血儿问题 总被引:1,自引:0,他引:1
黑白混血儿问题是美国黑、白种族关系史上一个很有意思的话题。在以混血为特征的美国社会,黑白混血儿不完全同于纯血黑人、也完全不同于其他混血儿的独特历史命运以及冒充白人的现象,既是对美国白人自认为血统纯正的讽刺,又揭示了建立在肤色基础上的种族歧视制度的脆弱性和荒谬性。 相似文献
78.
Sondra S. Teske Mark H. Weir Timothy A. Bartrand Yin Huang Sushil B. Tamrakar Charles N. Haas 《Risk analysis》2014,34(5):911-928
The effect of bioaerosol size was incorporated into predictive dose‐response models for the effects of inhaled aerosols of Francisella tularensis (the causative agent of tularemia) on rhesus monkeys and guinea pigs with bioaerosol diameters ranging between 1.0 and 24 μm. Aerosol‐size‐dependent models were formulated as modification of the exponential and β‐Poisson dose‐response models and model parameters were estimated using maximum likelihood methods and multiple data sets of quantal dose‐response data for which aerosol sizes of inhaled doses were known. Analysis of F. tularensis dose‐response data was best fit by an exponential dose‐response model with a power function including the particle diameter size substituting for the rate parameter k scaling the applied dose. There were differences in the pathogen's aerosol‐size‐dependence equation and models that better represent the observed dose‐response results than the estimate derived from applying the model developed by the International Commission on Radiological Protection (ICRP, 1994) that relies on differential regional lung deposition for human particle exposure. 相似文献
79.
对于网上性爱,迄今为止仍然缺乏科学的实证研究。本研究基于2010年全国14-61岁总人口的随机抽样调查的数据,第一次在具有总体代表性的意义上,运用多元线性回归分析的方法分析了中国各个社会阶层参与网上性爱的不同程度,发现网上性爱其实是中上社会阶层的主流文化。本文进一步进行检验,发现在16种网下的非主流的性行为实践中,只有"上年中有过一夜情"这样一种情况与"网上性爱参与程度"呈现为显著的相关关系;从而证明了"网上黄毒"的假设不成立。 相似文献
80.
认识储层岩石中含油饱和度及饱和度分布,对驱替机理的深入研究是非常重要的。为了搞清储层岩石在驱替过程中的饱和度分布情况,应用工业CT技术,提出了一种储层含油岩芯被驱替后的饱和度分布的CT密度差测量方法。在岩样的同一断面,分别对干岩样、饱和岩样及在驱替后的岩样进行CT扫描,重建相应的断层图象,测量所建图象的灰度值,计算出相应的密度值,用密度差法计算出饱和度及其分布值。在γ射线工业CT机“CD-300BG”上对某油田岩样进行了实际测量,获得的结果说明,采用CT密度差法测量饱和度分布是有效的。该方法与常规驱替法相比较,具有快速、精度高、无损岩样和能模拟地层状态测量等特点,是油田开发、油藏描述和地层评价的一种新的有效方法。 相似文献