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   6700篇
  免费   266篇
各国政治   335篇
工人农民   349篇
世界政治   546篇
外交国际关系   324篇
法律   4181篇
中国政治   30篇
政治理论   1159篇
综合类   42篇
  2023年   64篇
  2022年   39篇
  2021年   64篇
  2020年   126篇
  2019年   164篇
  2018年   224篇
  2017年   237篇
  2016年   246篇
  2015年   156篇
  2014年   213篇
  2013年   762篇
  2012年   219篇
  2011年   218篇
  2010年   152篇
  2009年   165篇
  2008年   192篇
  2007年   201篇
  2006年   183篇
  2005年   129篇
  2004年   162篇
  2003年   150篇
  2002年   115篇
  2001年   239篇
  2000年   241篇
  1999年   166篇
  1998年   78篇
  1997年   69篇
  1996年   61篇
  1995年   63篇
  1994年   66篇
  1993年   63篇
  1992年   124篇
  1991年   114篇
  1990年   138篇
  1989年   125篇
  1988年   139篇
  1987年   135篇
  1986年   102篇
  1985年   111篇
  1984年   85篇
  1983年   73篇
  1982年   55篇
  1981年   47篇
  1980年   40篇
  1979年   51篇
  1978年   36篇
  1976年   32篇
  1975年   30篇
  1974年   43篇
  1973年   29篇
排序方式: 共有6966条查询结果,搜索用时 31 毫秒
191.
192.
To analyze how Japan's competing objectives and specific policies have been evolving and how they trade off in today's regional security situation, this article argues that shifting Japanese foreign and security policies in Northeast Asia can be understood as ongoing responses to tensions along three key axes. First Japan confronts a tension between bilateralism and multilateralism; second Japan's economic and security interests are often at odds, and third, Japan still struggles with the competing pulls exerted by Asia on the one hand and the West (most particularly the United States) on the other.  相似文献   
193.
194.
Coleman D  Casey JT 《危机》2007,28(4):198-203
The treatment processes associated with reduced suicidal ideation have received little research attention. This study evaluates the influence on suicidal ideation of theory-based intrapsychic processes: maladaptive cognition and defensive style. Thirty-three community mental health patients completed questionnaires at two time points. Decreases in automatic thoughts were a strong correlate of decreased suicidal ideation, and decreases in immature defenses were a moderate strength correlate. These relationships remained significant even when controlling for initial level of depression. The theorized mechanisms of cognitive-behavioral and psychodynamic therapy had the expected effects on suicidal ideation. The strong association of decreased maladaptive cognitions with decreased suicidal ideation supports further development of cognitive-behavioral suicide interventions and clinical use of cognitive interventions. Psychodynamic processes in suicidal ideation and behavior warrant further exploration.  相似文献   
195.
The goals of the Postvention Taskforce of the International Association for Suicide Prevention (IASP) are to increase awareness of postvention and survivor issues. One of the strategies is to organize meetings. We report on the 1st International Suicide Postvention Seminar, held as a 1-day preevent at the 11th European Symposium on Suicide and Suicidal Behavior in Portoroz, Slovenia, September 2006. The seminar provided a state of the art review of the postvention field, with plenary presentations on research, psychotherapeutic care, development of national networks, and of postvention materials. We summarize the presentations below.  相似文献   
196.
The Journal of Technology Transfer - The paper investigates the relationship between public research and radical technological development. This study draws on the theory of recombinant innovation...  相似文献   
197.
Postmortem magnetic resonance imaging (MRI) is rarely used for the radiologic assessment of gunshot injuries, although it has clear advantages over postmortem computed tomography (CT) with regard to the imaging of soft tissue injuries. Another benefit in using MRI is that lodged projectiles composed of nonferromagnetic material such as lead present only marginal metal artifacts compared with severe artifacts on CT. This case report presents CT and MRI findings in a case with two gunshot wounds to the neck: a perforating wound and a nonperforating wound with a lead bullet lodged in the cervical spine. The decedent underwent CT and MRI before the scheduled autopsy. A ring of radiopaque material under the dermis in the fatty tissue was identified at both entrance wounds on CT, which was indicative of contact shots. The perforating gunshot was clearly indicated on CT by bullet fragments along the wound channel through the perforated 6th cervical vertebra and the fractured cricoid cartilage at the exit wound. The second trajectory, however, was only assumed based on the presence of gunshot residues at the entrance wound and the position of the lodged bullet. The radiologic assessment was severely impeded by the metal artifacts on CT. Barely noticeable metal artifacts on MRI allowed for clear visualization of the soft tissue injuries and the ruptured medulla oblongata. Only MRI clarified the soft tissue injuries of the brainstem noninvasively, which could provide specific and graphic information on the rapidity of death and the incapacitation of the victim.  相似文献   
198.
Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO.  相似文献   
199.
Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.  相似文献   
200.
Hacking trauma is prevalent in forensic cases involving genocide and dismemberment, but research into the identification of this type of trauma is lacking. The present study examines characteristics of hacking and blunt force skeletal trauma in order to determine if there is a point at which blunt force trauma becomes distinguishable from hacking trauma. Ten implements with a range of blade angles (i.e., the striking surface of the implement) were used in conjunction with a controlled-force hacking device to impact 100 limb bones of white-tailed deer (Odocoileus virginianus). Observations of the trauma included the occurrence and degree of fragmentation, the entrance widths of the impacts, and composite scores of six hacking characteristics, especially the distinctive V-shaped kerf. ANOVA tests and regression analyses were used to assess the relationships between these characteristics and the blade angles. A significant relationship (p-value = 0.011) was found between the composite hacking scores and the blade angles, indicating that blunt force and hacking trauma can be distinguished. The entrance widths of the impacts exhibited a significant relationship with the blade angles (p-value = 0.037). There was also a significant relationship between the visibility of a V-shaped kerf in the bones (p-value = 0.003), with visibility decreasing around the 60° blade angle. These data should assist in establishing guidelines to differentiate hacking and blunt force skeletal trauma in cases where the implement is on a spectrum between sharp and blunt.  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