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   1046篇
  免费   66篇
各国政治   76篇
工人农民   15篇
世界政治   27篇
外交国际关系   196篇
法律   513篇
中国共产党   7篇
中国政治   43篇
政治理论   89篇
综合类   146篇
  2024年   4篇
  2023年   10篇
  2022年   13篇
  2021年   21篇
  2020年   38篇
  2019年   27篇
  2018年   30篇
  2017年   30篇
  2016年   29篇
  2015年   28篇
  2014年   46篇
  2013年   76篇
  2012年   57篇
  2011年   74篇
  2010年   63篇
  2009年   69篇
  2008年   99篇
  2007年   91篇
  2006年   82篇
  2005年   41篇
  2004年   32篇
  2003年   29篇
  2002年   34篇
  2001年   23篇
  2000年   20篇
  1999年   11篇
  1998年   10篇
  1997年   1篇
  1996年   3篇
  1995年   3篇
  1989年   2篇
  1986年   3篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1982年   4篇
  1981年   1篇
  1980年   1篇
排序方式: 共有1112条查询结果,搜索用时 15 毫秒
151.
新安全视角下美国政府的气候政策   总被引:1,自引:0,他引:1  
"人类安全"逐渐成为一种新的安全理念,环境气候问题等各种影响人类安全和福祉的非传统安全问题日益引起广泛关注。全球性安全威胁的严重程度则取决于治理框架的反应能力。包括气候政策、法律和机构在内的气候环境治理框架能够最大限度地削弱全球化冲突的根源,避免影响的发生或减缓其进程。奥巴马上任以来美国新政府能源、环境和应对气候变化政策出现较大调整,大力推动新能源法案来减缓气候变化。这一政策转向具有深刻的历史动因和政治基础,并将给美国经济复苏和美国企业的国际竞争力带来压力,加剧美国对外贸易摩擦和削弱其在国际气候环境合作中的领导地位。  相似文献   
152.
结盟是相关行为体为了维护自己的安全利益根据自己的安全战略而进行的安全合作安排,盟友之间因安全环境的变化而产生的战略分歧和利益差异也将会导致同盟关系的调整。美韩同盟是冷战时期形成的,具有防御性且主要着眼于半岛安全之同盟的性质,但进入后冷战时期,尤其是"9.11"事件之后,基于安全环境和战略利益的变化,美韩两国对同盟关系进行了较大幅度的调整,调整之后的美韩同盟虽然在联合指挥协调机制问题上还存在着一定的不确定性,但从整体上看美韩同盟在本世纪初的调整则是一个走向强化的过程。  相似文献   
153.
对从长春地区腹泻仔猪结肠中分离到的1株毛滴虫进行了形态观察,并采用PCR扩增该毛滴虫的5.8SrRNA基因,测序后与国外已报道的三毛滴虫进行核酸同源性分析,并应用DNAStar软件绘制系统发育进化树。形态观察表明分离的毛滴虫为猪三毛滴虫。猪三毛滴虫长春分离株5.8SrRNA序列与国外已报道的三毛滴虫高度同源。系统发育进化树表明该序列与已报道的猪三毛滴虫5.8SrRNA(序列号U85966.1),牛胎儿三毛滴虫5.8SrRNA(序列号U85967.1,AF339736.1,AF466749.1,AF466750.1,AF466751.1)和T.mobiliensis5.8SrRNA(序列号U86612.1)同属于一个亚群,但与另1株猪三毛滴虫5.8SrRNA(序列号AY349190.1)亲缘关系较远。形态观察和5.8SrRNA基因分析表明,从长春地区分离的猪毛滴虫为猪三毛滴虫。  相似文献   
154.
This article examines the confluence of forces at work to shape U.S. policy toward Cuba since the late 1990s. Our approach examines four key factors involved in policymaking toward Cuba in this period: (1) the entry of new interest groups into the Cuba policy process and an "entrepreneurial" Congress; (2) the executive's constitutionally based interests; (3) bureaucratic interests; and (4) pressure from outside the United States. We examine U.S.–Cuba policy by describing each determinant in isolation and then by looking at the dynamic interaction among them, showing how they are linked together. In doing so, we argue that an analysis including multiple factors better explains U.S. policy toward Cuba than one that focuses on a single factor such as the power of the Cuban-American community.  相似文献   
155.
There is currently no published empirical evidence‐base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. In this study, human bones (n = 3) scanned using computed tomography were reconstructed as virtual 3D models (n = 6), and 3D printed using six commercially available printers, with osteometric data recorded at each stage. Virtual models and 3D prints were on average accurate to the source bones, with mean differences from ?0.4 to 1.2 mm (?0.4% to 12.0%). Interobserver differences ranged from ?5.1 to 0.7 mm (?5.3% to 0.7%). Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence‐base for validating 3D printed bones as demonstrative evidence.  相似文献   
156.
Telephone town halls are an increasingly prevalent method for members of Congress (MCs) to communicate with constituents, even while garnering popular criticism for failing to facilitate engagement and accountability. Yet scholars have paid little attention to the events and their effects, and even less to how they might be improved. To remedy this problem, we report on a field experiment in which four MCs joined their constituents in telephone town halls. Overall, participation in an event improved constituents’ evaluations of the format in general, and of the MC in particular. Furthermore, we studied how these events might be improved by evaluating a reform—a single‐topic focus with predistributed briefing materials—designed to enhance deliberative interaction. This reform enhanced effects on opinions of the format without significantly altering effects on attitudes toward the MC. Our results suggest that telephone town halls hold promise for constituents, officeholders, and democratic practice.  相似文献   
157.
In forensic anthropology, age‐at‐death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three‐dimensional laser scans of the pubic symphysis. We report a novel age‐related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age‐estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age‐estimates that are comparable to current practices with root‐mean‐square‐errors between 13.7 and 16.5 years.  相似文献   
158.
We present a new generation of three‐dimensional (3D) measuring systems, developed for the process of crime scene documentation. This measuring system facilitates the preparation of more insightful, complete, and objective documentation for crime scenes. Our system reflects the actual requirements for hierarchical documentation, and it consists of three independent 3D scanners: a laser scanner for overall measurements, a situational structured light scanner for more minute measurements, and a detailed structured light scanner for the most detailed parts of tscene. Each scanner has its own spatial resolution, of 2.0, 0.3, and 0.05 mm, respectively. The results of interviews we have conducted with technicians indicate that our developed 3D measuring system has significant potential to become a useful tool for forensic technicians. To ensure the maximum compatibility of our measuring system with the standards that regulate the documentation process, we have also performed a metrological validation and designated the maximum permissible length measurement error EMPE for each structured light scanner. In this study, we present additional results regarding documentation processes conducted during crime scene inspections and a training session.  相似文献   
159.
目的观察并分析肯定亲权关系的案件,探索STR基因座的突变规律。方法采用Goldeneye 20A试剂盒对20723例肯定亲权关系的案件筛选等位基因突变事件,统计各基因座的突变率和突变等位基因的来源、片段大小、突变步数及重复单位的增加或减少情况,分析突变相关因素的特点。结果 19个STR基因座共发现548例突变,观察到557个突变事件,基因座的突变率为0.07‰~2.23‰。父系突变与母系突变的比例为3.06∶1。突变以一步突变为主,增加与减少重复单位的情况相当;二步以上(含二步)突变更易出现重复单位减少。突变主要发生于中等位基因,重复单位增减比例相当,长等位基因突变中重复单位减少显著多于增加。父系突变出现重复单位增加与减少的比例相当,母系突变重复单位减少较增加多见。结论各基因座的突变率差异具有统计学意义,当出现1~2个基因座不符合遗传规律时,应当加测其他检测系统,并结合突变基因座的信息计算PI值,以进一步明确鉴定意见。  相似文献   
160.
We examined potential predictors of initial court agreement and 1‐year relitigation in a sample of contested paternity cases involving unmarried parents coming to court to establish paternity, child support, and other issues. Cases participated in an RCT of a parent program and of a waiting period between establishment of paternity and court hearing. We controlled for RCT study factors and used baseline assessment data to predict likelihood of reaching full agreement in the initial court hearing and relitigation in the following year. Findings suggest that cases in which parents get along better outside of court are more likely to reach agreement and less likely to return to court. Additionally, particular parent demographics predict lower likelihood of reaching initial agreement (e.g., parents are non‐White, father earns below $10,000 yearly), more relitigation (e.g., parents are non‐White, mother earns above $10,000 yearly, father has children with others), and less relitigation (e.g., father earns above $10,000 yearly). Child demographics and most parent relationship characteristics did not predict outcomes. We discuss findings and offer suggestions for court interventions.  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