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   1035篇
  免费   61篇
各国政治   87篇
工人农民   60篇
世界政治   87篇
外交国际关系   60篇
法律   540篇
中国共产党   1篇
中国政治   4篇
政治理论   250篇
综合类   7篇
  2023年   12篇
  2022年   11篇
  2021年   14篇
  2020年   29篇
  2019年   34篇
  2018年   74篇
  2017年   71篇
  2016年   65篇
  2015年   39篇
  2014年   44篇
  2013年   154篇
  2012年   50篇
  2011年   44篇
  2010年   44篇
  2009年   27篇
  2008年   31篇
  2007年   42篇
  2006年   27篇
  2005年   30篇
  2004年   39篇
  2003年   29篇
  2002年   19篇
  2001年   28篇
  2000年   26篇
  1999年   13篇
  1998年   3篇
  1997年   13篇
  1996年   2篇
  1995年   3篇
  1994年   3篇
  1992年   3篇
  1991年   4篇
  1990年   4篇
  1989年   7篇
  1988年   4篇
  1987年   3篇
  1986年   3篇
  1985年   7篇
  1984年   3篇
  1983年   8篇
  1982年   2篇
  1981年   3篇
  1980年   3篇
  1977年   4篇
  1976年   2篇
  1968年   2篇
  1967年   3篇
  1965年   1篇
  1964年   2篇
  1963年   2篇
排序方式: 共有1096条查询结果,搜索用时 15 毫秒
991.
A comparative morphological study of preimaginal stages (larvae and pupae) of Calliphora vicina Robineau-Desvoidy, 1830 is presented. The entomological samples came from laboratory colonies bred under controlled environmental conditions (25°C and 60% relative humidity). In this study, a recently published technique to clear Diptera larvae for light microscopy and a standard protocol for scanning electron microscopy were used. For the morphological comparison of larval instars I, II and III, and pupae of C. vicina, different larval regions (cephalic, thoracic and abdominal, including anal division), as well the internal chitinised cephalopharyngeal skeleton, were considered separately. Our results focus on showing the changes observed throughout development for the most important structures in the cephalic region (sensilla of maxillary palpus, antennae and oral ridges), the thoracic region (the first segment and its anterior spinose band) and in the anal division of the abdominal region (posterior spiracles and shape of the papillae). In addition, some morphological structures are described or pictured for the first time, such as the ventral organ and the anterior spiracle of larva I and the antenna sensilla, Keilin's organ and wrinkled area of the anal division of all instars. The cephalopharyngeal skeleton is an important structure for the taxonomy of Diptera larvae in all instars, including Calliphoridae. Our observations in C. vicina indicate that an in-depth review of the sclerite composition is needed. Pupae and larvae stages can only be compared by following the segmentary spinose bands and the anal segment, where the morphology of the posterior spiracles and papillae can be observed, in some cases despite the reduced condition of the latter.  相似文献   
992.
The 'herbal highs' market continues to boom. The added synthetic cannabinoids are often exchanged for another one with a high frequency to stay at least one step ahead of legal restrictions. While most of these substances were synthesized for pharmaceutical purposes and have been described in the scientific literature before, others originate from clandestine laboratories supplying this lucrative market. In this paper, the identification and structure elucidation of two synthetic cannabinoids is reported. The first compound, 1-[(5-fluoropentyl)-1H-indol-3yl]-(4-methylnaphthalen-1-yl)methanone, was found along with AM-2201 in a 'herbal mixture' obtained via the Internet. For isolation of the substance from the mixture, a newly developed flash chromatography method was used providing an inexpensive and fast way to gain pure reference substances from 'Spice' products for the timely development or enhancement of analytical methods in the forensic field. The second substance, 4-fluoronaphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-412) was seized by German authorities as microcrystalline powder, making it very likely that it will be found in 'herbal mixtures' soon.  相似文献   
993.
Two studies investigated the effects of information related to rape myths on Spanish college students' perceptions of sexual assault. In Study 1, 92 participants read a vignette about a nonconsensual sexual encounter and rated whether it was a sexual assault and how much the woman was to blame. In the scenario, the man either used physical force or offered alcohol to the woman to overcome her resistance. Rape myth acceptance (RMA) was measured as an individual difference variable. Participants were more convinced that the incident was a sexual assault and blamed the woman less when the man had used force rather than offering her alcohol. In Study 2, 164 college students read a scenario in which the woman rejected a man's sexual advances after having either accepted or turned down his offer of alcohol. In addition, the woman was either portrayed as being sexually attracted to him or there was no mention of her sexual interest. Participants' RMA was again included. High RMA participants blamed the victim more than low RMA participants and were less certain that the incident was a sexual assault, especially when the victim had accepted alcohol and was described as being sexually attracted to the man. The findings are discussed in terms of their implications for the prevention and legal prosecution of sexual assault.  相似文献   
994.
The present study examined gender differences in intimate partner homicide (IPH) and offender characteristics with the focus on putative gender-specific risk factors in a nationwide consecutive sample of homicide offenders. Data on all offenders (N = 642; 91 females, 551 males) convicted of homicide and subjected to a forensic psychiatric examination in Finland were obtained for the years 1995 and 2004. IPH offenders, 39 female and 106 male, were compared for risk factors with female and male offenders whose victims were not spouses. The forensic psychiatric examination reports were retrospectively analyzed, and the Hare Psychopathy Checklist-Revised (PCL-R) was rated. Significant gender differences were found in four risk factors: employment, intoxication of victim, self-defense, and quarrel, mostly related to alcohol as a factor of the offense. The findings support the notion that female IPH is linked to defensive reactions resulting from prior abuse, and that IPH offenders resemble the general population more than offenders of other types of homicide.  相似文献   
995.
Twelfth Night     
  相似文献   
996.
997.
998.
999.
1000.
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