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   453篇
  免费   24篇
各国政治   15篇
工人农民   61篇
世界政治   57篇
外交国际关系   14篇
法律   266篇
中国政治   10篇
政治理论   52篇
综合类   2篇
  2024年   1篇
  2023年   4篇
  2022年   5篇
  2021年   3篇
  2020年   15篇
  2019年   14篇
  2018年   25篇
  2017年   16篇
  2016年   20篇
  2015年   13篇
  2014年   24篇
  2013年   72篇
  2012年   21篇
  2011年   13篇
  2010年   14篇
  2009年   29篇
  2008年   24篇
  2007年   28篇
  2006年   20篇
  2005年   25篇
  2004年   14篇
  2003年   12篇
  2002年   15篇
  2001年   5篇
  2000年   2篇
  1999年   7篇
  1998年   4篇
  1997年   3篇
  1996年   2篇
  1995年   1篇
  1994年   4篇
  1993年   2篇
  1992年   6篇
  1991年   5篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1980年   2篇
排序方式: 共有477条查询结果,搜索用时 15 毫秒
341.
Teacher ratings of 336 preschool children (mean age = 48 months) attending two urban Head Start programs were collected to examine the influence of contextual variables of teacher training, classroom, and site on the prevalence of significant problems. The prevalence of externalizing behaviors in the problem range was higher than expected and fewer children were rated in the well-adjusted range on social competence measures. Psychometric characteristics of the ratings indicated that teachers in this urban setting were less consistent in their ratings of internalizing problems, calling into question the lack of elevation of such problems in this population. Ratings by teachers and teacher assistants of the same children showed low agreement; the level of ratings was not affected by differences in training but did vary across classrooms. Hierarchical linear modeling analyses of the entire sample showed significant effects of classroom and site on problem behaviors and social competence. These results reveal the wide variation in problem frequency across classrooms, which needs to be considered in the implementation and evaluation of evidence-based interventions. Further, these results point to the importance of studying possible lasting effects on children exposed to these differing contexts.  相似文献   
342.
Allele frequencies for the 19 short tandem repeat (STR) loci CSF1PO, D2S1338, D3S1358, D5S818, D7S820, D8S306, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, DHFRP2 (FOLP23), F13A01, FES/FPS, FGA, TH01, TPOX, and vWA were obtained from a sample of 106 unrelated Filipinos from different regions of the Philippine archipelago.  相似文献   
343.
We present a validated method for the simultaneous analysis of basic drugs which comprises a sample clean-up step, using mixed-mode solid-phase extraction (SPE), followed by LC-MS/MS analysis. Deuterated analogues for all of the analytes of interest were used for quantitation. The applied HPLC gradient ensured the elution of all the drugs examined within 14 min and produced chromatographic peaks of acceptable symmetry. Selectivity of the method was achieved by a combination of retention time, and two precursor-product ion transitions for the non-deuterated analogues. Oral fluid was collected with the Intercept, a FDA approved sampling device that is used on a large scale in the US for workplace drug testing. However, this collection system contains some ingredients (stabilizers and preservatives) that can cause substantial interferences, e.g. ion suppression or enhancement during LC-MS/MS analysis, in the absence of suitable sample pre-treatment. The use of the SPE was demonstrated to be highly effective and led to significant decreases in the interferences. Extraction was found to be both reproducible and efficient with recoveries >76% for all of the analytes. Furthermore, the processed samples were demonstrated to be stable for 48 h, except for cocaine and benzoylecgonine, where a slight negative trend was observed, but did not compromise the quantitation. In all cases the method was linear over the range investigated (2-200 microg/L) with an excellent intra-assay and inter-assay precision (coefficients of variation <10% in most cases) for QC samples spiked at a concentration of 4, 12 and 100 microg/L. Limits of quantitation were estimated to be at 2 microg/L with limits of detection ranging from 0.2 to 0.5 microg/L, which meets the requirements of SAMHSA for oral fluid testing in the workplace. The method was subsequently applied to the analysis of Intercept samples collected at the roadside by the police, and to determine MDMA and MDA levels in oral fluid samples from a controlled study.  相似文献   
344.
The most complex and risky decisions made by forensic psychiatrists revolve around the decision to release insanity acquittes from custody. This decision has several levels of risk, including the potential liability to the psychiatrist as well as the possible risk to the community. A single bad outcome, even if not predictable, can have disastrous results, not only for victims, but also for the releasing facility. Since predicting violence has so many problems, we chose to look at completeness of treatment instead, so we could say to the Court, "We don't know about violence, but we do know that he has vastly improved." Since many NGRI (Not Guilty by Reason of Insanity) patients spend years in the hospital, they are also expensive. They have rights, as well; therefore the complex assessment must be done as quickly and as accurately as possible. We have developed a spread sheet program to compare these multiple factors, and have compared it against the clinical decisions we have made in more than 100 discharges. We believe this gives a framework for decision-making that will increase the consistency of this process.  相似文献   
345.
The purpose of this study was to investigate levels of interpersonal dependency, an indicator of insecure attachment in adulthood, among batterers court-mandated into domestic violence treatment. The study collected data from 158 batterers beginning treatment and 25 nonviolent men. Analysis indicated that batterers demonstrated significantly elevated levels of interpersonal dependency, relative to the nonviolent comparison group. These findings indicate that more research is needed before the role of interpersonal dependency in the etiology and maintenance of domestic violence can be understood. Program Director, Alternatives to Violence Program  相似文献   
346.
347.
The relationship between nonformal education (NFE) and democracy has not been subject to empirical examination. Given the prominence that NFE has gained in many countries, such as those in Africa, this inattention is unfortunate. Using data from a survey involving a probability sample of 1484 Senegalese citizens, this paper examines the effects of education, both formal and nonformal, on political participation among rural Senegalese. The results indicate that NFE and formal education tend to have similar effects on several political behaviors, but the effect of NFE generally appears to be stronger. NFE has a positive impact on political participation. NFE increases the likelihood that one will vote and contact officials regarding community and personal problems. In addition, NFE has a strong, positive impact on community participation.Michelle T. Kuenzi, Assistant Professor, Department of Political Science, University of Nevada Las Vegas, 4505 Maryland Pkwy, Box 455029, Las Vegas, NV 89154-5029, USA (michele.kuenzi@ccmail.nevada.edu)  相似文献   
348.
In the spring of 2000, the National Institute of Standards and Technology and nineteen participants conducted a comparison of smokeless powder additive compositional measurements. The purpose of this exercise was to determine the state-of-the-practice for forensic smokeless powder determinations. For the comparison, two handgun reloading powder samples were mixed and were compositionally evaluated for homogeneity by NIST. Participant laboratories included military, academic, and state/local, federal, and international forensic agencies. We solicited qualitative data identifying nitroglycerin, diphenylamine, N-nitrosodiphenylamine, and ethyl centralite. In addition, some laboratories provided identification of additional ingredients, such as nitrocellulose, or reported other measurements, such as dimensional morphology. In this paper, laboratory identification of the smokeless powder additives and a summary of the measurement methods used for the evaluations are presented. All laboratories correctly identified NG and the major stabilizers. Some disparity between laboratories was noted for the identification of minor (<0.01% by weight) stabilizers and stabilizer decomposition products.  相似文献   
349.
350.
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