全文获取类型
收费全文 | 9043篇 |
免费 | 329篇 |
专业分类
各国政治 | 394篇 |
工人农民 | 367篇 |
世界政治 | 699篇 |
外交国际关系 | 349篇 |
法律 | 5902篇 |
中国政治 | 54篇 |
政治理论 | 1542篇 |
综合类 | 65篇 |
出版年
2023年 | 78篇 |
2021年 | 69篇 |
2020年 | 152篇 |
2019年 | 195篇 |
2018年 | 239篇 |
2017年 | 287篇 |
2016年 | 284篇 |
2015年 | 190篇 |
2014年 | 259篇 |
2013年 | 976篇 |
2012年 | 266篇 |
2011年 | 266篇 |
2010年 | 209篇 |
2009年 | 196篇 |
2008年 | 257篇 |
2007年 | 299篇 |
2006年 | 286篇 |
2005年 | 214篇 |
2004年 | 245篇 |
2003年 | 243篇 |
2002年 | 198篇 |
2001年 | 338篇 |
2000年 | 319篇 |
1999年 | 236篇 |
1998年 | 103篇 |
1997年 | 82篇 |
1996年 | 84篇 |
1995年 | 83篇 |
1994年 | 84篇 |
1993年 | 73篇 |
1992年 | 145篇 |
1991年 | 159篇 |
1990年 | 141篇 |
1989年 | 158篇 |
1988年 | 137篇 |
1987年 | 155篇 |
1986年 | 137篇 |
1985年 | 156篇 |
1984年 | 125篇 |
1983年 | 143篇 |
1982年 | 97篇 |
1981年 | 95篇 |
1980年 | 70篇 |
1979年 | 100篇 |
1978年 | 75篇 |
1977年 | 70篇 |
1976年 | 61篇 |
1974年 | 62篇 |
1973年 | 60篇 |
1971年 | 53篇 |
排序方式: 共有9372条查询结果,搜索用时 15 毫秒
951.
952.
Comparing Electronic News Media Reports of Potential Bioterrorism-Related Incidents Involving Unknown White Powder to Reports Received by the United States Centers for Disease Control and Prevention and the Federal Bureau of Investigation: U.S.A., 2009–2011 下载免费PDF全文
Geroncio C. Fajardo M.D. M.B.A. M.S. M.S. Joseph Posid M.P.H. Stephen Papagiotas M.P.H. Luis Lowe M.S. M.P.H. 《Journal of forensic sciences》2015,60(Z1):S76-S82
There have been periodic electronic news media reports of potential bioterrorism-related incidents involving unknown substances (often referred to as “white powder”) since the 2001 intentional dissemination of Bacillus anthracis through the U.S. Postal System. This study reviewed the number of unknown “white powder” incidents reported online by the electronic news media and compared them with unknown “white powder” incidents reported to the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Federal Bureau of Investigation (FBI) during a 2-year period from June 1, 2009 and May 31, 2011. Results identified 297 electronic news media reports, 538 CDC reports, and 384 FBI reports of unknown “white powder.” This study showed different unknown “white powder” incidents captured by each of the three sources. However, the authors could not determine the public health implications of this discordance. 相似文献
953.
Jamie K. Pringle Ph.D. John P. Cassella Ph.D. John R. Jervis Ph.D. Anna Williams Ph.D. Peter Cross M.Sc. Nigel J. Cassidy Ph.D. 《Journal of forensic sciences》2015,60(4):1052-1060
In homicide investigations, it is critically important that postmortem interval and postburial interval (PBI) of buried victims are determined accurately. However, clandestine graves can be difficult to locate; and the detection rates for a variety of search methods (ranging from simple ground probing through to remote imaging and near‐surface geophysics) can be very low. In this study, simulated graves of homicide victims were emplaced in three sites with contrasting soil types, bedrock, and depositional environments. The long‐term monthly in situ monitoring of grave soil water revealed rapid increases in conductivity up to 2 years after burial, with the longest study evidencing declining values to background levels after 4.25 years. Results were corrected for site temperatures and rainfall to produce generic models of fluid conductivity as a function of time. The research suggests soilwater conductivity can give reliable PBI estimates for clandestine burials and therefore be used as a grave detection method. 相似文献
954.
Contribution of Antemortem Computed Tomography Findings to Cause of Death Determination: An Unusual Fatal Stroke 下载免费PDF全文
Camille Rérolle M.D. Julien Pucheux M.D. Thierry Lefrancq M.D. Céline Barrault M.D. Pauline Saint‐Martin M.D. Ph.D. 《Journal of forensic sciences》2015,60(4):1095-1098
In the case reported here, the antemortem computed tomography scan (CT scan) was essential in the forensic investigation. A 32‐year‐old man was found fully awake with a facial abrasion, after what seemed to be a car accident. He lost consciousness suddenly one hour after initial management. Successive CT scan showed a facial fracture and a metallic foreign body in the carotid canal associated with an occlusion/dissection of the left internal carotid, a pseudoaneurysm, and a carotid‐cavernous fistula. The victim died from a stroke. Autopsy confirmed that the facial abrasion was a gunshot entrance wound, the metallic foreign body being a projectile. Intracranial vascular injuries linked with gunshot wounds are most of the time isolated and due to pelet embolism. The observed vascular injury association has never been described in the existing literature. The CT scan provided a better understanding of the chronology of events that led to death. 相似文献
955.
Investigating the Postmortem Molecular Biology of Cartilage and its Potential Forensic Applications 下载免费PDF全文
Shawna N. Bolton M.Sc. Michael P. Whitehead Ph.D. Jayesh Dudhia Ph.D. Timothy C. Baldwin Ph.D. Raul Sutton Ph.D. 《Journal of forensic sciences》2015,60(4):1061-1067
This study investigated the postmortem molecular changes that articular cartilage undergoes following burial. Fresh pig trotters were interred in 30‐cm‐deep graves at two distinct locations exhibiting dissimilar soil environments for up to 42 days. Extracts of the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joint cartilage from trotters disinterred weekly over 6 weeks were analyzed by Western blot against the monoclonal antibody 2‐B‐6 to assess aggrecan degradation. In both soil conditions, aggrecan degradation by‐products of decreasing molecular size and complexity were observed up to 21 days postmortem. Degradation products were undetected after this time and coincided with MCP/MTP joint exposure to the soil environment. These results show that cartilage proteoglycans undergo an ordered molecular breakdown, the analysis of which may have forensic applications. This model may prove useful for use as a human model and for forensic investigations concerning crimes against animals and the mortality of endangered species. 相似文献
956.
TrueAllele® Genotype Identification on DNA Mixtures Containing up to Five Unknown Contributors 下载免费PDF全文
Mark W. Perlin Ph.D. M.D. Jennifer M. Hornyak M.S. Garett Sugimoto M.S. Kevin W.P. Miller Ph.D. 《Journal of forensic sciences》2015,60(4):857-868
Computer methods have been developed for mathematically interpreting mixed and low‐template DNA. The genotype modeling approach computationally separates out the contributors to a mixture, with uncertainty represented through probability. Comparison of inferred genotypes calculates a likelihood ratio (LR), which measures identification information. This study statistically examined the genotype modeling performance of Cybergenetics TrueAllele® computer system. High‐ and low‐template DNA mixtures of known randomized composition containing 2, 3, 4, and 5 contributors were tested. Sensitivity, specificity, and reproducibility were established through LR quantification in each of these eight groups. Covariance analysis found LR behavior to be relatively invariant to DNA amount or contributor number. Analysis of variance found that consistent solutions were produced, once a sufficient number of contributors were considered. This study demonstrates the reliability of TrueAllele interpretation on complex DNA mixtures of representative casework composition. The results can help predict an information outcome for a DNA mixture analysis. 相似文献
957.
An Accelerated Analytical Process for the Development of STR Profiles for Casework Samples 下载免费PDF全文
Significant efforts are being devoted to the development of methods enabling rapid generation of short tandem repeat (STR) profiles in order to reduce turnaround times for the delivery of human identification results from biological evidence. Some of the proposed solutions are still costly and low throughput. This study describes the optimization of an analytical process enabling the generation of complete STR profiles (single‐source or mixed profiles) for human identification in approximately 5 h. This accelerated process uses currently available reagents and standard laboratory equipment. It includes a 30‐min lysis step, a 27‐min DNA extraction using the Promega Maxwell®16 System, DNA quantification in <1 h using the Qiagen Investigator® Quantiplex HYres kit, fast amplification (<26 min) of the loci included in AmpF?STR® Identifiler®, and analysis of the profiles on the 3500‐series Genetic Analyzer. This combination of fast individual steps produces high‐quality profiling results and offers a cost‐effective alternative approach to rapid DNA analysis. 相似文献
958.
959.
960.