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   719篇
  免费   44篇
各国政治   6篇
工人农民   29篇
世界政治   7篇
外交国际关系   29篇
法律   374篇
中国共产党   22篇
中国政治   84篇
政治理论   32篇
综合类   180篇
  2023年   8篇
  2022年   5篇
  2021年   10篇
  2020年   10篇
  2019年   11篇
  2018年   13篇
  2017年   19篇
  2016年   32篇
  2015年   13篇
  2014年   32篇
  2013年   46篇
  2012年   53篇
  2011年   48篇
  2010年   40篇
  2009年   39篇
  2008年   43篇
  2007年   44篇
  2006年   50篇
  2005年   46篇
  2004年   54篇
  2003年   42篇
  2002年   35篇
  2001年   26篇
  2000年   11篇
  1999年   6篇
  1998年   1篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   4篇
  1991年   3篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   3篇
  1983年   1篇
排序方式: 共有763条查询结果,搜索用时 296 毫秒
111.
Vitreous humor (VH) and synovial fluid (SF) become optional postmortem samples for biochemistry investigation. However, few studies have explored SF as a potential source, and there is still controversy whether the biochemical concentrations in bilateral VH are the same. We explored the concentrations of biochemical substances in both VH and SF, and compared between both sides and between the fluids. We also correlated the biochemical concentrations in both fluids. All samples were centrifuged after collection and the supernatant fluids were used for the analysis. The results indicated no significant difference in the constituent concentrations between the fluids from both sides (> 0.05). Sodium, potassium, chloride, and magnesium concentrations were significantly higher in the VH, but in vice versa for glucose, uric acid, and creatinine concentrations (< 0.001). Sodium, potassium, glucose, lactate, urea, uric acid, and creatinine concentrations between both fluids showed significant correlation (< 0.05), but not chloride and magnesium concentrations.  相似文献   
112.
Synthetic cannabinoids are sprayed onto plant material and smoked for their marijuana‐like effects. Clandestine manufacturers modify synthetic cannabinoid structures by creating closely related analogs. Forensic laboratories are tasked with detection of these analog compounds, but targeted analytical methods are often thwarted by the structural modifications. Here, direct analysis in real time coupled to accurate mass time‐of‐flight mass spectrometry (DART‐TOF‐MS) in combination with liquid chromatography quadruple time‐of‐flight mass spectrometry (LC‐QTOF‐MS) are presented as a screening and nontargeted confirmation method, respectively. Methanol extracts of herbal material were run using both methods. Spectral data from four different herbal products were evaluated by comparing fragmentation pattern, accurate mass and retention time to available reference standards. JWH‐018, JWH‐019, AM2201, JWH‐122, 5F‐AKB48, AKB48‐N‐(4‐pentenyl) analog, UR144, and XLR11 were identified in the products. Results demonstrate that DART‐TOF‐MS affords a useful approach for rapid screening of herbal products for the presence and identification of synthetic cannabinoids.  相似文献   
113.
The time since deposition (TSD) of a bloodstain is a valuable piece of evidence for forensic scientists to determine the time at which a crime took place. The objective of this study was to determine whether attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy could be used to estimate the TSD of a bloodstain in a relatively early period (from 0 min to the time required for the bloodstain to dry out). For this purpose, we used ATR‐FTIR to study the variation in absorbance at certain wavelengths as rat and human blood sample dried out. The absorbance at 3308/cm (A3308) was found to have a close correlation with the TSD during this time period, and the changes in A3308 during the drying of rat and human blood drops under the same controlled conditions showed similar results. The current study indicates that ATR‐FTIR spectroscopy has potential as a tool for estimating TSD at early time periods of blood deposition.  相似文献   
114.
While prior research has shown that the probability of detection plays a role in the decision-making of many offenders, much less is known on offenders’ relative success in avoiding arrest. In this study, we draw from detailed criminal career data on 172 offenders involved in lucrative criminal activities to examine the role of criminal competence in the probability of being arrested in a given month. We examine a particular aspect of competence, criminal efficiency, which is defined as the ability to earn a relatively large amount of money for each crime committed. Our research design allows us to disentangle the effect of criminal efficiency as a static trait of offenders from the dynamic variations in efficiency that offenders experience over time. Results show that efficiency is a strong, negative predictor of arrest, both at the static and dynamic levels.  相似文献   
115.
This study tested the hypothesis that investments in early childhood schools have short-term crime reducing effects in neighborhoods. Time series data from the city of Tulsa, Oklahoma, were analyzed to evaluate the effects of an early childhood school built in the neighborhood of Kendall-Whittier as part of a larger neighborhood revitalization plan, on violent and property crime. Results revealed that after controlling for city-wide crime trends and monthly fluctuations, violent crime declined significantly in Kendall-Whittier. Further analysis indicated that the possible crime-reducing effects of school investments on violent crime spread beyond Kendall-Whittier, and no displacement was found. The results for property crime were mixed. The study demonstrates the use of clustering analysis, a useful tool in neighborhood-level research to identify comparison neighborhoods. The findings shed light on the possibility that investments in early childhood schools can yield results in a shorter term than anticipated, making them a desirable component of urban revitalization.  相似文献   
116.
目的考察阿维菌素在急性中毒死家兔体内的再分布。方法按最小致死量一次性灌胃250mg/kg阿维菌素,HPLC法检测家兔死后0h、24h、48h和72h中阿维菌素的含量。结果给家兔一次性灌胃250mg/kg阿维菌素的临床死亡时间为120.6±9.2min(±s,n=10);测定了阿维菌素的致死血浓度和致死组织浓度;家兔死后0h~72h心血和各主要脏器组织中阿维菌素含量存在体内再分布现象;确定肝、肾、肺为最佳组织检材。结论阿维菌素在急性中毒死家兔体内的再分布数据,对法医办理此类案件具有重要参考价值。  相似文献   
117.
狭义刑法解释若干问题探析   总被引:5,自引:0,他引:5  
刑法解释只能在确切的刑法含义范围内进行解释 ,而不能超出刑法含义容量的最大界限。刑法解释应该以“自解释确定之日起施行”更加合适。刑法解释的效力及于刑法的施行期间 ,对于该解释实施前已生效的处理结果 ,应当从有利于被告人的原则来决定是否改判。  相似文献   
118.
张淼 《东北亚论坛》2005,14(6):69-72
刑法是国家之中的重要法律部门。日本自明治维新以来发生了深刻的变化,日本的刑法为了适应社会的发展而不断发生变化。到二次世界大战结束之前,发生了数次变革,这种变化发生的历程深刻体现着日本社会发展和法制发展进程中的被动性,而这种被动性中又有着很强的独立性。  相似文献   
119.
Abstract: Thin layer chromatography (TLC) is a technique that is commonly employed in the forensic drug analysis of pharmaceutical preparations. Detection is typically accomplished using various visualization spray reagents. Conventional gas chromatography–mass spectrometry (GC‐MS) analysis is typically performed to confirm the TLC results. Depending on the drugs tested and the instrument conditions required, this confirmation can take up to an hour to complete. Direct analysis in real time (DART?) is an ionization source, coupled to an accurate‐mass time‐of‐flight mass spectrometer that has the capability to ionize materials under ambient conditions. To streamline analysis, the combination of TLC with DART? detection is proposed to screen and subsequently identify drug compounds, all from the same TLC plate. DART? confirmations of TLC analyses take <10 min to complete and compare favorably to GC‐MS in sensitivity and selectivity. This study validates the use of TLC‐DART in the forensic identification of the components of several pharmaceutical preparations.  相似文献   
120.
Determination of the time of death is one goal of medicolegal death investigations. Algor mortis has been used as a measure of the postmortem interval (PMI). We prospectively recorded the core temperatures of 19 adult bodies entering our morgue cooler and at 3, 6, and 9 h of refrigeration. We then compared the cooling rate with the calculated body mass index (BMI). For each individual body, the rate of cooling was fairly linear with no evidence of a plateau. There was fair to moderate correlation between the BMI and the cooling rate: cooling rate = -0.052 (BMI) + 3.52. The probability of linearity in any given case was 36%. Variables affecting this correlation included the presence and the layers of clothing and if the clothing was wet. Our data confirm that algor mortis is of very limited utility in determining the PMI in bodies that have been refrigerated.  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