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   363篇
  免费   11篇
各国政治   30篇
工人农民   5篇
世界政治   9篇
法律   287篇
中国政治   12篇
政治理论   30篇
综合类   1篇
  2024年   38篇
  2023年   150篇
  2022年   2篇
  2021年   38篇
  2020年   6篇
  2019年   5篇
  2018年   3篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   2篇
  2013年   27篇
  2012年   11篇
  2011年   10篇
  2010年   12篇
  2009年   11篇
  2008年   6篇
  2007年   2篇
  2006年   6篇
  2005年   4篇
  2004年   4篇
  2003年   2篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1991年   3篇
  1989年   3篇
  1988年   1篇
  1986年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
排序方式: 共有374条查询结果,搜索用时 15 毫秒
141.
Soil is useful in criminal investigations as it is highly variable and readily transferred. Forensic geologists use several different techniques to removal soil from evidence prior to the analysis of inorganic components. There has been recent interest from the forensic science community to analyze environmental deoxyribonucleic acid (eDNA) associated with soil to augment existing forensic analyses. Notably however, limited research has been conducted to compare commonly used soil removal methods for downstream eDNA analysis. In this study, three soil removal methods were assessed: picking/scraping, sonication, and swabbing. Three mock evidence types (t-shirts, boot soles, and trowels) were sampled in triplicate with each removal method (n = 27). Soil samples underwent DNA isolation, quantification, and amplification of four genomic barcode regions: 16S for bacteria, ITS1 for fungi, ITS2 for plants, and COI for arthropods. Amplicons were prepared into libraries for DNA sequencing on an Illumina® MiniSeq. DNA concentrations were highest in picked/scraped samples and were statistically significant compared with swabbed and sonicated samples. Amplicon sequence variants (ASVs) were identified, and removal methods had no impact on the recovery of the total number of target ASVs. Additionally, when assessing each sample in multidimensional space, picked/scraped samples tended to cluster separately from swabbed and sonicated samples. The soil core used a reference in this study also clustered with the picked/scraped samples, indicating that these samples may be more reflective of the communities collected from soil cores. Based on these data, we identified that picking/scraping is an acceptable soil removal method for eDNA analysis.  相似文献   
142.
143.
Ketamine deemed as a psychoactive substance has gained popularity for recreational use owing to its hallucinogenic and dissociative effects. Understanding the synthetic processes of ketamine can provide essential clues for law enforcement officers against illicit ketamine manufacturing. In this case report, a chemical company was being monitored by law enforcement officers due to its importation of precursors and materials that could be used for the synthesis of illicit drugs. After materials and products seized from this chemical company were employed for analyses using gas chromatography–mass spectrometry, liquid chromatography–high-resolution mass spectrometry, and nuclear magnetic resonance analyses, ketamine, hydroxylamine, 2-chlorophenyl cyclopentyl ketone, and cyclopentanone p-toluenesulfonylhydrazone were identified. In addition, a novel process for the synthesis of ketamine precursor 2-chlorophenyl cyclopentyl ketone from cyclopentanone p-toluenesulfonylhydrazone and 2-chlorobenzaldehyde was validated. This is the first report to uncover this novel process for the synthesis of 2-chlorophenyl cyclopentyl ketone and can be used to increase awareness among law enforcement officers and forensic practitioners about these novel starting materials for the synthesis of ketamine.  相似文献   
144.
Digitalization has increased the number of video surveillance systems that sometimes capture crime images. Traditional methods of human height estimation use projective geometry. However, sometimes they cannot be used because the video camera surveillance system is not available or has been moved and there are no reference lines on the frame. Scientific studies have developed a new method for human height estimation using 3D laser scanning. This model necessarily requires a series of approximations, which increase the final measurement error. To overcome this problem, in the present study, images of a subject are projected directly on the 3D model, estimating the height of the subject. This article describes the methodological approach adopted through the analysis of a real case study in a controlled environment executed by Carabinieri Forensic Investigation Department (Italy). The aim is to obtain a human anthropometric measure derived from frames extracted from the videos associated with the digital survey of the framed area obtained with 3D laser scanning and point cloud analysis. The result is the height estimation of five subjects filmed by a camera obtained through the combination of 2D images extracted by a DVR/surveillance systems with 3D laser scanning. Results show that most estimated measurements are less than the real measurement of the subject; it also depends on the posture of the subject while walking. Furthermore, results shows the differences between the real height and the estimated height with a statistical approach.  相似文献   
145.
Nerium oleander is an ornamental evergreen shrub belonging to the family Apocynaceae. The Apocynaceae family includes the attractive evergreen shrub known as oleander. The cardiotoxic glycoside, oleandrin, is present in all portions of the common oleander plant. Oleander consumption can result in deadly situations accidentally or as a suicide attempt. After consuming kettle-boiled oleander leaf extract as part of a suicide attempt, an 80-year-old man was discovered comatose in his home and taken to our emergency room. The patient's heart rate was 30 beats per minute, and he had hypotension. Arterial blood gas analysis revealed remarkable metabolic acidosis and hyperkalemia (K: 7.7 mEq/L). An electrocardiogram showed a wide QRS wave, similar to a sine curve. The patient collapsed following cardiac arrest soon after hospital arrival. Veno-arterial extracorporeal membrane oxygenation was initiated; however, the patient eventually died. The serum level of oleandrin at hospital arrival, subsequently measured by LC–MS/MS, was found to be 33.4 ng/mL, far above the levels reported in previous fatal cases.  相似文献   
146.
Abstract

The discipline of public administration in the Philippines has been undergoing its version of an ‘identity crisis’ over the past decade. This crisis has been manifested in four areas: (1) the inordinate influence of mostly American public administration theories and concepts upon Philippines public administration has led Filipino academics in the early to mid-1980s to ask the question ‘is there a Philippine public administration?’; (2) the perceived disconnect between theories of public administration as taught in schools and the realities in the outside world has raised questions of the relevance of the discipline to real world challenges; (3) the continued frustration over the perception that in spite of many public administration and governance reforms, the Philippines continues to be among the more corrupt nations in the region; and (4) the recent fascination of academics in other disciplines, especially economists, that ‘institutions matter’, has led some public administration scholars to argue that their discipline has been arguing precisely the same point since the 1950s.  相似文献   
147.
Oversight function is a major component of the activities of modern legislatures irrespective of the form of government in practice. This study examines the extent to which the Nigerian legislature, characterised by infrequent appearances on the political scene and operating in an environment largely dominated by the executive arm, has performed its oversight role. The study, which is basically empirical, argues that the Nigerian legislature has been incapable of effectively performing its oversight role because, in addition to constraints like executive interference, crippling internal conflict, inexperience and high rate of members turnover hampering legislative efficiency, the legislature has compromised its role. However, occasional flashes of a measure of assertiveness by the legislature suggest that with effective mitigation of its internal problems its performance will improve as legislative culture deepens.  相似文献   
148.
149.
A young adult black female, known to be a prostitute and suspected of smuggling narcotics, was found dead in her apartment in a state of early decomposition. Oval‐shaped gray‐white masses of exogenous origin protruded from the anus. The autopsy showed dilatation of the folds of the large intestine, which were almost completely filled with these oval‐shaped gray‐white masses of foreign material. The uterus was enlarged with multiple large leiomyomas. Toxicological tests of blood and the foreign material revealed no toxicologically relevant substances. Kaolin was detected in a sample of the foreign material from the large intestine. The immediate cause of death was intestinal obstruction due to the formation of a kaolin bezoar with simultaneous compression of the large intestine by the enlarged myomatous uterus. Subsequent revelation of a habit the deceased had brought from her native country led to the conclusion that this exotic custom was responsible for her death.  相似文献   
150.
A 32‐year‐old pregnant woman in the 25th week of pregnancy underwent oral glucose tolerance screening at the diabetologist's. Later that day, she was found dead in her apartment possibly poisoned with Chlumsky disinfectant solution (solutio phenoli camphorata). An autopsy revealed chemical burns in the digestive system. The lungs and the brain showed signs of severe edema. The blood of the woman and fetus was analyzed using gas chromatography with mass spectrometry and revealed phenol, its metabolites (phenyl glucuronide and phenyl sulfate) and camphor. No ethanol was found in the blood samples. Both phenol and camphor are contained in Chlumsky disinfectant solution, which is used for disinfecting surgical equipment in healthcare facilities. Further investigation revealed that the deceased woman had been accidentally administered a disinfectant instead of a glucose solution by the nurse, which resulted in acute intoxication followed by the death of the pregnant woman and the fetus.  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