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   12454篇
  免费   407篇
各国政治   444篇
工人农民   548篇
世界政治   806篇
外交国际关系   460篇
法律   7494篇
中国共产党   34篇
中国政治   142篇
政治理论   2775篇
综合类   158篇
  2021年   68篇
  2020年   177篇
  2019年   164篇
  2018年   260篇
  2017年   305篇
  2016年   346篇
  2015年   274篇
  2014年   271篇
  2013年   1209篇
  2012年   277篇
  2011年   330篇
  2010年   266篇
  2009年   335篇
  2008年   399篇
  2007年   398篇
  2006年   398篇
  2005年   365篇
  2004年   368篇
  2003年   306篇
  2002年   302篇
  2001年   400篇
  2000年   364篇
  1999年   296篇
  1998年   206篇
  1997年   147篇
  1996年   169篇
  1995年   164篇
  1994年   168篇
  1993年   165篇
  1992年   228篇
  1991年   282篇
  1990年   243篇
  1989年   237篇
  1988年   256篇
  1987年   237篇
  1986年   252篇
  1985年   222篇
  1984年   198篇
  1983年   186篇
  1982年   131篇
  1981年   142篇
  1980年   120篇
  1979年   113篇
  1978年   116篇
  1977年   100篇
  1976年   85篇
  1975年   78篇
  1974年   90篇
  1973年   94篇
  1969年   64篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
943.
This study sought to assign a rough order of magnitude for the amount of explosive residue likely to be available in real-world searches for clandestine explosives. A variety of explosives (TNT, TATP, HMX, AN, RDX, PETN) in various forms (powder, flake, detonating cord, plastic) were carefully weighed or cut into containers, and the amount of residue inadvertently remaining on the work area, hands, or containers was quantified. This was used to evaluate the spillage potential of each explosive. The adhesion of each explosive to a glass surface was quantified from amount of explosive adhering to the inside of a glass vial into which the explosive had been placed and then removed by vigorous tapping. In powdered form, most of the explosives--TNT, PETN, RDX, HMX, and TATP--exhibited similar spillage and adhesion to glass. However, PETN as sheet explosive and plasticized RDX (C-4), showed very little potential to contaminate surfaces, either by spillage or adhesion to glass.  相似文献   
944.
945.
Involuntary treatment is a concept often familiar to psychiatrists. In clinical practice, it usually involves the hospitalization and pharmacological management of patients with severe mental disorders. However, the scope of involuntary treatment is not limited to the management of mental illness alone. Psychiatric patients afflicted with medical illnesses may require hospitalization and invasive procedures for optimal management of these disorders. The following case illustrates a dilemma in which a psychotic patient refuses life-saving medical treatment; however, the treatment itself carries significant risk of morbidity and mortality. This article reviews the ethical, legal and clinical implications of making such difficult treatment decisions.  相似文献   
946.
This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.  相似文献   
947.
Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution.  相似文献   
948.
Supraphysiologic doses of testosterone are associated with increased aggression that is hypothesized to be a function of testosterone serum concentrations, mood, and personality. The study attempted to characterize this relationship among weightlifters who were users (n = 10) and nonusers (n = 18) of anabolic steroids. Participants were interviewed using the Modified Mania Rating Scale and Hamilton Rating Scale for Depression to assess mood, the Buss-Durkee Hostility Inventory (BDHI) and Point Subtraction Aggression Paradigm (PSAP) to assess aggression, and the Personality Disorder Questionnaire (PDQ-R) to assess personality. Blood samples were obtained for the determination of total, free, and weakly bound testosterone. Comparisons of continuous variables between testosterone users and non-users were performed with a parametric (unpaired t-test) or non-parametric (Mann-Whitney) test where appropriate. Correlations with testosterone were examined separately for testosterone users and non-users, using Spearman rank correlation. The subjective (BDHI) and objective (PSAP) assessments of aggression found that supranormal testosterone concentrations were associated with increased aggression. However, the PDQ-R results suggest that this finding was confounded by the personality disorder profile of the steroid users, because steroid users demonstrated Cluster B personality disorder traits for antisocial, borderline, and histrionic personality disorder.  相似文献   
949.
950.
Diphenhydramine is an antihistamine available in numerous over-the-counter preparations. Often used for its sedative effects in adults, it can cause paradoxical central nervous system stimulation in children, with effects ranging from excitation to seizures and death. Reports of fatal intoxications in young children are rare. We present five cases of fatal intoxication in infants 6, 8, 9, 12, and 12 weeks old. Postmortem blood diphenhydramine levels in the cases were 1.6, 1.5, 1.6, 1.1 and 1.1 mg/L, respectively. Anatomic findings in each case were normal. In one case the child's father admitted giving the infant diphenhydramine in an attempt to induce the infant to sleep; in another case, a daycare provider admitted putting diphenhydramine in a baby bottle. Two cases remain unsolved; one case remains under investigation. The postmortem drug levels in these cases are lower than seen in adult fatalities. We review the literature on diphenhydramine toxicity, particularly as it pertains to small children, and discuss the rationale for treating these cases as fatal intoxications.  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