全文获取类型
收费全文 | 2784篇 |
免费 | 136篇 |
专业分类
各国政治 | 223篇 |
工人农民 | 183篇 |
世界政治 | 393篇 |
外交国际关系 | 172篇 |
法律 | 1389篇 |
中国政治 | 10篇 |
政治理论 | 534篇 |
综合类 | 16篇 |
出版年
2023年 | 26篇 |
2022年 | 19篇 |
2021年 | 43篇 |
2020年 | 73篇 |
2019年 | 108篇 |
2018年 | 143篇 |
2017年 | 167篇 |
2016年 | 168篇 |
2015年 | 106篇 |
2014年 | 151篇 |
2013年 | 434篇 |
2012年 | 131篇 |
2011年 | 106篇 |
2010年 | 73篇 |
2009年 | 69篇 |
2008年 | 103篇 |
2007年 | 112篇 |
2006年 | 114篇 |
2005年 | 102篇 |
2004年 | 97篇 |
2003年 | 82篇 |
2002年 | 79篇 |
2001年 | 53篇 |
2000年 | 51篇 |
1999年 | 36篇 |
1998年 | 28篇 |
1997年 | 24篇 |
1996年 | 21篇 |
1995年 | 26篇 |
1994年 | 17篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1979年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1967年 | 7篇 |
1966年 | 3篇 |
排序方式: 共有2920条查询结果,搜索用时 15 毫秒
121.
122.
123.
124.
With increasing frequency, relatively small, fragmentary evidence thought to be osseous or dental tissue of human origin is submitted to the forensic laboratory for DNA analysis with the request for positive identification. Prior to performing DNA analysis, however, it is prudent to first perform a presumptive test or "screen" to determine whether the questioned material may be eliminated from further consideration. When material is shown not to be consistent with bone/teeth, DNA testing is not performed. When such determinations cannot be made from gross morphological features, elemental analysis can be indicative. This presumptive test is made possible by applying scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) in conjunction with an X-ray spectral database recently developed by the FBI laboratory. This database includes spectra for many different materials including known examples of bone and tooth from many different contexts and representing the full range of taphonomic conditions. Results of SEM/EDS analysis of evidence can be compared to these standards to determine if they are consistent with bone and/or tooth and, if not, then what the material might represent. Analysis suggests that although the proportions and amounts of calcium and phosphorus are particularly important in differentiating bone and tooth from other materials, other minor differences in spectral profile can also provide significant discrimination. Analysis enables bone and tooth to be successfully distinguished from other materials in most cases. Exceptions appear to be ivory, mineral apatite, and perhaps some types of corals. 相似文献
125.
Validation of a 16-locus fluorescent multiplex system 总被引:24,自引:0,他引:24
Krenke BE Tereba A Anderson SJ Buel E Culhane S Finis CJ Tomsey CS Zachetti JM Masibay A Rabbach DR Amiott EA Sprecher CJ 《Journal of forensic sciences》2002,47(4):773-785
STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results. 相似文献
126.
The suicide rate on death row for the period 1976 through 1999 was found to be high (113 per 100,000 per year), some five times higher than the suicide rate for the male population of the United States. The death row suicide rate was predicted by features of the death row population (negatively with the population on death row) and by social indicators of the society as a whole (negatively with birth and divorce rates and positively with marriage rates). 相似文献
127.
Torres MC Osuna E Pérez-Cárceles MD Gómez-Zapata M Luna A 《The American journal of forensic medicine and pathology》2002,23(2):155-158
The authors evaluated the usefulness of the postmortem biochemical analysis of ionic ratios in different parts of the heart and their relation to cardiac damage caused by chest trauma, as observed by anatomopathologic study. Fifty-nine 59 cases were studied, selected from routine necropsies, and samples were taken from different sites of cardiac tissue. The cause of death was trauma in 40 cases and nontraumatic causes in 19 cases. The object of this study was to analyze the levels of Na+, K+, Ca+2, Mg+2, and Zn+2 in different zones of the heart, and the relationship between intracellular and extracellular ion ratios and the different causes of death and any anatomopathologic alterations observed. The biochemical tests revealed a possible relation between the ionic values and cause of death. Alterations in cell membrane permeability and corresponding modification of the ionic ratios were produced earlier than histologic alterations, which need longer to establish themselves whether or not they follow a traumatic process. 相似文献
128.
129.
130.
In their essay "When Efficiency Is Unbelievable: Normative Lessons from 30 Years of City–County Consolidations," published in the July/August 2005 issue of PAR , Leland and Thurmaier make an important contribution to understanding how city–county consolidation occurs. They revise the widely accepted Rosenbaum and Kammerer model of consolidation and posit that "strong arguments" based on economic development, especially in the absence of organized opposition, led to victory for consolidation advocates. In this response, we argue that efforts to identify a set of arguments or charter provisions that will lead to successful consolidation are misguided. The real story in consolidation campaigns is how participants use heresthetical arguments in an effort to turn their opponents into political losers. What makes arguments strong or weak is not their substantive policy focus, but how they are structured. 相似文献