首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18535篇
  免费   210篇
各国政治   849篇
工人农民   517篇
世界政治   1444篇
外交国际关系   754篇
法律   11214篇
中国共产党   1篇
中国政治   114篇
政治理论   3707篇
综合类   145篇
  2021年   82篇
  2020年   412篇
  2019年   442篇
  2018年   502篇
  2017年   577篇
  2016年   617篇
  2015年   526篇
  2014年   564篇
  2013年   2064篇
  2012年   412篇
  2011年   510篇
  2010年   654篇
  2009年   608篇
  2008年   453篇
  2007年   495篇
  2006年   530篇
  2005年   404篇
  2004年   415篇
  2003年   409篇
  2002年   383篇
  2001年   552篇
  2000年   469篇
  1999年   390篇
  1998年   266篇
  1997年   226篇
  1996年   210篇
  1995年   213篇
  1994年   209篇
  1993年   203篇
  1992年   284篇
  1991年   317篇
  1990年   289篇
  1989年   293篇
  1988年   280篇
  1987年   266篇
  1986年   294篇
  1985年   281篇
  1984年   286篇
  1983年   252篇
  1982年   212篇
  1981年   178篇
  1980年   171篇
  1979年   192篇
  1978年   137篇
  1977年   132篇
  1976年   95篇
  1975年   98篇
  1974年   107篇
  1973年   100篇
  1972年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
    
Housing insecurity is a known threat to child health understanding predictors of housing insecurity can help inform policies to protect the health of young children in low-income households. This study sheds light on the relationship between housing insecurity and availability of housing that is affordable to low-income households.

We developed a county-level index of availability of subsidized housing needed to meet the demand of low-income households. Our results estimate that if subsidized units are made available to an additional 5% of the eligible population, the odds of overcrowding decrease by 26% and the odds of families making multiple moves decrease by 31%. Both of these are known predictors of poor child health outcomes. Thus, these results suggest that state and federal investments in expanding the stock of subsidized housing could reduce housing insecurity and thereby also improve the health and well-being of young children, including their families' food security status.  相似文献   

902.
    
This paper is situated within the rhetorical turn in political science and investigates the discourses constructed by Trotskyist parties in order to justify the policy of electoral participation despite poor electoral performance. A wide range of texts are examined from eight organizations that contested seats in the 2010 UK General Election. The thrust of Trotskyist discourse downplayed dismal vote totals, contextualizing them by reference to pro-Labour tactical voting and elaborating a variety of benefits that emerged from electoral participation. It is argued that such analysis could usefully be incorporated into the study of party responses to electoral problems and setbacks.  相似文献   
903.
    
  相似文献   
904.
Australian state governments are engaging in strategic planning processes and publishing departmental and/or overall state strategic plans. One means of achieving the goals outlined in these strategic plans is via public procurement processes. Investments in construction projects by governments are strategic in nature and made to create infrastructure, which enables the provision of public services. This article investigates the contribution that construction procurement across the five Australian state governments who expend the most money on infrastructure makes towards the achievement of government strategy. The research draws on interviews with experienced project managers to assess whether public sector construction procurement is aligned or disconnected with publically stated government strategies.  相似文献   
905.
    
Criminal self-efficacy, an antisocial belief representing positive appraisal of one's capabilities to enact crime, is theorized to drive criminal behaviour, but few measures exist. Our aim was to re-validate one measure of criminal self-efficacy by re-testing its ability to predict recidivism.  相似文献   
906.
    
Fluoxetine is a selective serotonin reuptake inhibitor, commonly used for the treatment of a variety of psychopathological conditions. As such, fluoxetine may be expected to appear in clinical and forensic cases. Dermestes maculatus De Geer (Coleoptera: Dermestidae) has been recognized as a relevant component of the insect fauna associated with decomposing human and animal remains. Experiments were conducted to study the effect of fluoxetine on developing D. maculatus using two‐drug administration models: a non‐living animal model (pork muscle) and a living one (Sus scrofa L. pigs). We assessed the duration of immature stages and total life cycle, as well as morphological parameters (body length, cephalic width, and weight). The effect of fluoxetine was studied at an overdose concentration: In the non‐living animal model the drug was mixed with macerated pork muscle (2000 mg/kg) and in the living animal model, pigs were given the drug orally (833 mg/kg). A control was used for each model. Daily observations were performed from the beginning to the end of the experiments. GC‐MS was used for drug detection and quantification. There were no statistically significant differences in the duration of immature stages, life cycle, larval mortality, morphological parameters, or sex ratio, between treatment and control, regardless of the drug administration model. Given that fluoxetine had no detectable effect on the development of D. maculatus, detection of this drug in forensic situations would not compromise the accuracy of PMI estimations.  相似文献   
907.
    
Leading police scholars and practitioners were asked to reflect on the most urgent issues that need to be addressed on the topic of use of force. Four themes emerged from their contributions: use of force and de-escalation training needs to improve and be evaluated; new ways of conceptualizing use of force encounters and better use of force response models need to be developed; the inequitable application of force, and how to remediate biases, needs to be more fully understood; and misconceptions about police use of force need to be identified and corrected. The highlighted topics serve as an agenda for future research. Such research should provide greater insight into when, where, and why force is used by police officers, and how it can be applied appropriately. If implemented, the practical recommendations included in the contributions should have a positive impact on police performance, public trust and confidence in the police, and citizen and officer safety.  相似文献   
908.
    
Accurate age estimates of immature necrophagous insects associated with a human or animal body can provide evidence of how long the body has been dead. These estimates are based on species-specific details of the insects’ aging processes, and therefore require accurate species identification and developmental stage estimation. Many professionals who produce or use identified organisms as forensic evidence have little training in taxonomy or metrology, and appreciate the availability of formalized principles and standards for biological identification. Taxonomic identifications are usually most readily and economically made using categorical and qualitative morphological characters, but it may be necessary to use less convenient and potentially more ambiguous characters that are continuous and quantitative if two candidate species are closely related, or if identifying developmental stages within a species. Characters should be selected by criteria such as taxonomic specificity and metrological repeatability and relative error. We propose such a hierarchical framework, critique various measurements of immature insects, and suggest some standard approaches to determine the reliability of organismal identifications and measurements in estimating postmortem intervals. Relevant criteria for good characters include high repeatability (including low scope for ambiguity or parallax effects), pronounced discreteness, and small relative error in measurements. These same principles apply to individuation of unique objects in general.

Key points

  • Metrological rigour can increase in forensic entomology by selecting measurements based on their metrological qualities.
  • Selection of high-quality features for morphological identification of organisms should consider these criteria: (1) pronounced discreteness of features (minimising group overlap or maximizing interval); (2) high repeatability of assessment (such as symmetrical width rather than asymmetrical length); (3) small relative error in measurement (selecting the physically largest continuous rigid feature for measurement).
  • These metrological principles also apply to individuation of unique objects in general.
  相似文献   
909.
    
  相似文献   
910.
    
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号