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   1556篇
  免费   64篇
各国政治   43篇
工人农民   52篇
世界政治   34篇
外交国际关系   58篇
法律   605篇
中国共产党   86篇
中国政治   235篇
政治理论   96篇
综合类   411篇
  2024年   2篇
  2023年   18篇
  2022年   21篇
  2021年   17篇
  2020年   32篇
  2019年   25篇
  2018年   13篇
  2017年   35篇
  2016年   32篇
  2015年   25篇
  2014年   81篇
  2013年   130篇
  2012年   97篇
  2011年   105篇
  2010年   82篇
  2009年   121篇
  2008年   124篇
  2007年   143篇
  2006年   149篇
  2005年   86篇
  2004年   84篇
  2003年   60篇
  2002年   51篇
  2001年   45篇
  2000年   17篇
  1999年   6篇
  1998年   3篇
  1997年   4篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1984年   2篇
排序方式: 共有1620条查询结果,搜索用时 666 毫秒
201.
《Justice Quarterly》2012,29(1):77-106
The present study examined the effects of institutional pressures on homeland security preparedness among law enforcement agencies in Illinois. The data come from the Illinois Homeland Security Survey (IHSS). Specifically, the study employed three theories to explain homeland security preparedness: contingency theory, resource dependence theory, and institutional theory. We hypothesized that institutional pressures will lead to isomorphism as agencies attempt to conform to institutional expectations about appropriate activities in a homeland security era. To evaluate these theories and their impact on homeland security practices, the authors used confirmatory factor analysis. The IHSS data lend strong support to the application of organizational theory as a lens through which homeland security preparedness can be understood. Institutional pressures, such as professional and government publications, training, professional associations, and the actions of peer agencies, significantly influenced municipal and county agencies in Illinois. Funding, while often thought important to encourage preparedness, was not a significant predictor. The results of this analysis advance our understanding of homeland security preparedness via institutional theory by suggesting that the larger environment is salient.  相似文献   
202.
吴喜梅 《河北法学》2012,30(11):52-57
现代化农业的建设离不开对农业科学持续大量的投入,加强农业投资立法,从法律层面明确各农业投资主体的权利义务,严格规范各投资主体的农业投资活动,为农业投资行为提供法律的确定性和可预见性具有重要意义.农业投资立法应当以财政资金引导多元投入原则、保护各投资主体合法利益原则、农业可持续发展原则和科学管理与有效监督原则为指导,在明确各农业投资主体法律地位的基础上构建以《农业法》为核心的农业投资法律体系.  相似文献   
203.
The transfer of DNA from hands to objects by holding or touching has been examined in the past. The main purpose of this study was to examine the variation in the amount of DNA transferred from hands to glass, fabric and wood. The study involved 300 volunteers (100 for glass, 100 for fabric and 100 for wood) 50% of which were male and 50% female. The volunteers held the material for 60 s. The DNA was recovered from the objects using a minitape lift, quantified using the Quantifiler kit assay, extracted using a ‘Qiagen® QIAamp DNA mini kit’ and amplified using the AmpFlSTR® SGM Plus™ Amplification Kit at 28 cycles. The results show that using ANOVA there was a significant difference (F = 8.2, p < 0.05) between the three object types in the amount of DNA recovered. In terms of DNA transfer and recovery, wood gave the best yield, followed by fabric and then glass. The likelihood of success of obtaining a profile indicative of the holder was approximately 9% for glass samples, 23% for fabric and 36% for wood. There was no significant difference between the amount of DNA transferred by male or female volunteers. In this study good shedder status, as defined by obtaining useful profiles of 6 or more alleles, is estimated at approximately 22% of the population. The phenomenon of secondary transfer was observed when mixed DNA profiles were obtained but the incidence was low at approximately 10% of the total number of samples. DNA profiles corresponding to more than one person were found on objects which had been touched by only one volunteer. Although secondary transfer is possible the profiles obtained from touched objects are more likely to be as a result of primary transfer rather than a secondary source.  相似文献   
204.
205.
“Touch DNA” is a form of trace DNA that is presumed to be deposited when an individual touches something and leaves behind DNA-containing skin cells, sweat, or other fluids. While touch DNA is often the result of direct contact (i.e., primary transfer), it can also be indirectly transferred between surfaces or individuals (e.g., secondary or tertiary transfer). Even experts cannot distinguish between different types of transfer and do not fully understand which variables affect direct versus indirect transfer or how often each type of transfer occurs. In this study, we utilize an innovative protocol that combines a paired male and female transfer DNA experimental design with an Amelogenin qPCR assay to generate data on primary, secondary, and tertiary DNA transfer. We report frequencies of indirect DNA transfer and also investigate the potential effects of participant age, self-identified ethnicity, and skin conditions on DNA transfer. Out of 22 experimental trials, we detected primary transfer (male + female) in 71% of trials, secondary DNA transfer in 50% of trials, and tertiary DNA transfer in 27% of trials. No significant associations were found between primary DNA transfer and age, self-identified ancestry, or skin conditions, however, all individuals with sloughing skin conditions demonstrated primary DNA transfer and we suggest this variable be explored in larger samples. These results contribute to a better understanding of the conditions under which secondary and tertiary DNA transfer occurs and can be used to propose realistic DNA transfer scenarios in court cases.  相似文献   
206.
The ability to detect low level DNA brings with it the uncertainty of whether the detected DNA is a result of transfer. To address this uncertainty, a simulation study was conducted in which a mock illicit drug packet was placed into the personal bags of individuals. When the average transit time of the packets was increased from around 2 h to more than 14 h, the percentage of the DNA profiles recovered from the packets which could be attributed to the individuals increased greatly from 5.3% to 48.6%. We found that drug packers who were poor shedders could not be included as contributors to the DNA profiles from the drug packets at all and there was a higher chance that individuals other than themselves could be included as contributors to the DNA profile recovered from drug packets. We also found that it was equally likely that the drug packers who had direct contact with the drug packets and bag owners who did not, could be included as contributors to the DNA profiles recovered from the packets. The results in this study highlight the importance of taking into consideration the transit time of drug packet, the shedder status of the alleged packer and the history of an item, when evaluating DNA evidence in the context of illicit drug activities.  相似文献   
207.
正Researchers debunk the theory that the Chinese Government is tackling food security by buying African land By Corrie Dosh It’s the kind of headline that sells magazines:"China Buys Up the World."It appeared in a November 2010 issue of The Economist,illustrated by a faceless,militaristic figure loading cars,oil barrels,power lines and various manufactured goods into  相似文献   
208.
了解贵州少数民族自治地方人口素质的现状,分析形成的原因,提出解决问题的措施,促进贵州省少数民族自治地方人口素质的提高。  相似文献   
209.
民族贫困地区开发面临的最大约束是人口素质问题.人口素质提高对民族贫困地区经济增长、缓解贫困,使人口与经济、资源、环境相互协调,可持续发展,具有非常关键的作用.本文以海南中部为例,实证分析民族贫困地区存在着人力资本投资不足及教育资源和卫生资源的配置效率欠佳问题,指出应通过加大教育投资的制度创新力度等措施,从根本上解决问题.  相似文献   
210.
In the present study the genetic variation of different Peruvian populations was investigated. The samples for this study were obtained from 669 individuals distributed among 11 populations from Peru. All samples were analyzed using 23 autosomal STR markers. The Arlequin v3.5.2.2 software was used to determine the genetic distances (Fst) of the studied populations. Notable population substructure was detected between some populations.  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