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   578篇
  免费   21篇
各国政治   59篇
工人农民   46篇
世界政治   45篇
外交国际关系   28篇
法律   236篇
中国政治   49篇
政治理论   133篇
综合类   3篇
  2023年   4篇
  2021年   8篇
  2020年   9篇
  2019年   16篇
  2018年   22篇
  2017年   27篇
  2016年   23篇
  2015年   15篇
  2014年   14篇
  2013年   107篇
  2012年   22篇
  2011年   15篇
  2010年   12篇
  2009年   12篇
  2008年   14篇
  2007年   24篇
  2006年   15篇
  2005年   15篇
  2004年   17篇
  2003年   14篇
  2002年   22篇
  2001年   11篇
  2000年   10篇
  1999年   10篇
  1998年   5篇
  1997年   11篇
  1996年   5篇
  1995年   5篇
  1994年   10篇
  1993年   4篇
  1992年   4篇
  1991年   5篇
  1990年   14篇
  1989年   4篇
  1988年   8篇
  1987年   5篇
  1986年   4篇
  1985年   4篇
  1984年   6篇
  1983年   9篇
  1982年   4篇
  1981年   6篇
  1979年   6篇
  1978年   2篇
  1977年   3篇
  1976年   2篇
  1975年   4篇
  1974年   2篇
  1968年   2篇
  1964年   2篇
排序方式: 共有599条查询结果,搜索用时 15 毫秒
431.
Psychological defence mechanisms have been considered important personality processes in the onset, maintenance and recovery of mental disorders. More recently, their application to understanding presenting problems and as potential outcome indicators for forensic patients has been recommended. However, to date there have been no investigations into the reliability and factor structure of defence mechanism assessments for this population. The current study investigated the factor structure, internal consistency and test-retest reliability of the Defence Style Questionnaire-40 (DSQ) for 160 adult male UK forensic patients. The three-factor model of defences proposed by the DSQ-40 developers was not confirmed in the study sample. Reliability indices of the three factors indicated that the Immature factor was the most ‘acceptable’ in terms of internal consistency. Test-retest reliability coefficients ranged from .70 to .91. A revised three-factor structure that closely corresponds to the original validation study is recommended following an exploratory factor analysis. The findings are compared with previous reliability and factor analytic evaluations of the DSQ-40, and recommendations for its use with forensic patients are discussed.  相似文献   
432.
Organophosphate (OP) pesticides are highly toxic substances and are frequently represented as poisons. In order to qualify and quantify the selected OP pesticides (methyl paraoxon, ethyl paraoxon, methyl parathion, fenitrothion, and ethyl parathion), micellar electrokinetic chromatography and short‐end injection were investigated. This is the first time that this combination has been used to separate OP pesticides. A capillary with 8.5 cm effective length was used, and the analytes were separated within 2.1 min. Separation conditions including buffer (type, pH, and concentration), sodium dodecyl sulfate concentration, and separation voltage were optimized. The limit of detection (LOD) was estimated in the range of 10–20 μM. The OP pesticides spiked in artificial saliva and drinking water gave superior peak profiles, and good average recoveries 95.6% and 62.3%, respectively. Overall, a rapid method with excellent resolution and efficiency was developed and successfully applied in the analysis of potential sample matrixes.  相似文献   
433.
Blind trials of an onsite saliva drug test for marijuana and opiates   总被引:5,自引:0,他引:5  
The objective of these clinical trials was to calculate the performance, limit of detection, specificity and sensitivity of a novel, semi-quantitative immunoassay for drugs of abuse in saliva and to determine operator bias when measured blind by four different operators. The test is based on lateral flow gold particle technology coupled with digital photography to provide a semi-quantitative end point. The performance of the test was compared with that of enzyme immunoassays and GC/MS methods. Volunteers consumed marijuana or codeine and their saliva was collected 0.25 to 24 h later with the Cozart RapiScan collection device. The sensitivity and specificity of the opiate test were both 100%+/-10.4% for codeine for 9 h after dosing. The cutoff of the marijuana test at 10 ng/mL THCA was too high to detect marijuana use for more than a few hours after smoking. There was no operator bias because the results were presented in written form either as "positive" or "negative" for each of the five drug classes on the screen of the hand-held reader.  相似文献   
434.
435.
This article addresses the rise of poverty, violence, and decay in the pre-indus- trialized societies of the Roman and Chinese Empires. Major similarities between the declines of these two Empires include the unchecked authority of those in charge, an arbitrary market meant to serve the elite, and the costs of financing wars and luxury living. This is contrasted with the rage and unruliness of large numbers of lower class members who lacked the basic necessities of life, including food and work. One difference is that strong ethnic self-awareness in China survived the collapse of the empire, whereas Romes willingness to grant its land to foreigners contributed to subsequent fragmentation.  相似文献   
436.
A new set of multiplexed PCR primers has been applied to the analysis of human skeletal remains to determine their efficacy in analyzing degraded DNA. These primer sets, known as Miniplexes, produce shorter amplicons (50-280 base pairs (bp)) than standard short tandem repeat (STR) kits, but still utilize the 13 CODIS STR loci, providing results that are searchable on national DNA databases. In this study, a set of 31 different human remains were exposed to a variety of environmental conditions, extracted, and amplified with commercial and Miniplex DNA typing kits. The amplification efficiency of the Miniplex sets was then compared with the Promega PowerPlex 16 system. Sixty-four percent of the samples generated full profiles when amplified with the Miniplexes, while only 16% of the samples generated full profiles with the Powerplex 16 kit. Complete profiles were obtained for 11 of the 12 Miniplex loci with amplicon sizes less than 200 bp. These data suggest smaller PCR amplicons may provide a useful alternative to mitochondrial DNA for anthropological and forensic analysis of degraded DNA from human skeletal remains.  相似文献   
437.
Psychological maltreatment, including verbal aggression, has been implicated as an important contributor to children's behavioral problems. The present study looked specifically at the relationship between different forms of maternal verbal aggression and their association with children's adjustment. Mothers from Violent and Nonviolent families were compared on their use of various verbal aggression tactics, as measured by the Conflict Tactics Scale (Straus, 1979). Mothers from both groups used threats and insults with comparable frequency. In both groups, insults were predictive of children's adjustment. The relationship was particularly striking in children from violent homes. We conclude that chronic exposure to inter-parental violence may render children emotionally susceptible to maternal disparagement.  相似文献   
438.
439.
440.
Determining the location and distribution of cockpit and aircrew-related equipment within the wider debris field of a military aircraft crash site is an essential first step in planning and executing the recovery of missing aircrew members presumed still to be on the site. Understanding the spatial relationship of these materials improves the likelihood of finding and recovering the remains of the aircrew during the excavation of an aircraft crash site. Since the greater portion of these unaccounted for crewmembers were involved in aircraft with single-seat cockpits or cockpits with two or three seats in tandem, pre-analysis of the debris pattern may be more-or-less straightforward. Larger, multiple-personnel aircraft, on the other hand, create a potentially more complex analytical situation given the aircrew's greater freedom of movement within the aircraft. Nevertheless, the same fundamental principles apply and, indeed, have been successfully so for some time in the civilian arena. But older aircraft crash sites, i.e., those dating to World War II, Korea, or the Vietnam conflict, have been and still are undergoing taphonomic processes that progressively alter these relationships. The following will illustrate that exchange of information between the anthropologist/archaeologist and the life-support analyst is required to maximize the effectiveness of field recovery and demonstrates the relationship between the recovery of life-support equipment and human remains and the effect that aircraft type has on this relationship.  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