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   220篇
  免费   7篇
各国政治   8篇
工人农民   25篇
世界政治   21篇
外交国际关系   19篇
法律   119篇
中国政治   2篇
政治理论   33篇
  2022年   1篇
  2021年   3篇
  2020年   6篇
  2019年   6篇
  2018年   7篇
  2017年   9篇
  2016年   8篇
  2015年   3篇
  2014年   7篇
  2013年   43篇
  2012年   3篇
  2011年   8篇
  2010年   5篇
  2009年   11篇
  2008年   7篇
  2007年   9篇
  2006年   11篇
  2005年   6篇
  2004年   9篇
  2003年   5篇
  2002年   10篇
  2001年   10篇
  2000年   6篇
  1999年   5篇
  1998年   1篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1992年   3篇
  1991年   1篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有227条查询结果,搜索用时 15 毫秒
11.
12.
This article examines the mode of understanding and experiences of family relationships of Chinese migrant women in Britain. In contrast to much existing research work on the patterns and experiences of postwar settlement of unskilled Chinese male labourers in Britain, the focus here is on the life stories of 41 Chinese women with different migration trajectories and varying economic and cultural capital. Their oral testimonies reveal Chinese women's diverse expectations and experiences of migrant family relationships and their different strategies to achieve self-fulfillment both within and outside the confines of the migrant family. For some women, migration brings opportunities for a fulfilling and independent lifestyle. They are successful in negotiating their way around and sometimes out of their initial familial and social position. For others, they bear the disproportionate cost and labour of familial strategies of advancement and remain vulnerable to the most constraining aspects of diasporic existence.  相似文献   
13.
The authors describe three accidental deaths resulting from occupational hazards involving environmental gas alterations. One involved the displacement of oxygen caused by leakage of liquid nitrogen during the installation of a magnetic resonance imaging system. Two involved elevated environmental carbon dioxide concentrations: dry ice sublimation in a walk-in refrigerator in a research laboratory, and activation of a carbon dioxide fire alarm-extinguisher system by a woman locked in a bank vault. The autopsy findings, scene investigations, and certifications of these deaths, as related to the mechanisms of death, are discussed.  相似文献   
14.
15.
There is a growing awareness of the complex and largely negative attitudes many girls in the UK hold towards physical activity in general and Physical Education (PE) in particular. This research in the UK involves a qualitative study of six Year 9 girls' experiences and motivations in PE.Reflexive interpretation and biographical analysis of in-depth interviews are utilized to explore the themes of the relationship between “sportiness” and heterosexual desirability; and the polarized images of “tomboy” and “girlie.” Work by Connell [Connell, R.W. (1987). Gender and power. Cambridge: Polity Press.] on the gender order, and theories arising from the cultural analysis tradition on teenage girls' subcultures and identity formation are drawn on in order to make sense of the girls' narratives.The findings of this research reveal that images of teenage girls and young women being physically active are non-congruous with the traditional ideologies of acceptable femininity. This paper describes how these girls negotiate the contradictions and the tensions caused by the “femininity deficit” incurred in PE by creating “double identities” and living “split lives.”  相似文献   
16.
17.
This paper describes a collaborative exercise organised under the auspices of the European Network of Forensic Science Institutes (ENFSI). The purpose of this EU (European Union) funded group is to carry out research to enable STR loci to be compared between European laboratories, ultimately leading to the formation of a pan-European database. Accordingly, an exercise was designed to evaluate a prototype STR multiplex system manufactured by Applied Biosystems (ABD). Each laboratory was sent 12 samples to analyse along with a multiplex kit. Of specific interest was the definition of parameters to define the efficiency of the system. Stutter, split allelic peaks (differing by one base), pull-up, heterozygous balance and between locus balance were all objectively measured. Once the important parameters are defined it is possible to directly compare performances of different multiplexes and the different laboratories carrying out the tests. Since the multiplex used was a prototype system, this exercise cannot be regarded as a proficiency test.  相似文献   
18.
PENDULUM--a guideline-based approach to the interpretation of STR mixtures   总被引:2,自引:0,他引:2  
Several years ago, a theory to interpret mixed DNA profiles was proposed that included a consideration of peak area using the method of least squares. This method of mixture interpretation has not been widely adopted because of the complexity of the associated calculations. Most reporting officers (RO) employ an experience and judgement based approach to the interpretation of mixed DNA profiles. Here we present an approach that has formalised the thinking behind this experience and judgement. This has been written into a computer program package called PENDULUM. The program uses a least squares method to estimate the pre-amplification mixture proportion for two potential contributors. It then calculates the heterozygous balance for all of the potential sets of genotypes. A list of "possible" genotypes is generated using a set of heuristic rules. External to the programme the candidate genotypes may then be used to formulate likelihood ratios (LR) that are based on alternative casework propositions. The system does not represent a black box approach; rather it has been integrated into the method currently used by the reporting officers at the Forensic Science Service (FSS). The time saved in automating routine calculations associated with mixtures analysis is significant. In addition, the computer program assists in unifying reporting processes, thereby improving the consistency of reporting.  相似文献   
19.
A single nucleotide polymorphism (SNP) multiplex has been developed to analyse highly degraded and low copy number (LCN) DNA template, i.e. <100 pg, for scenarios including mass disaster identification. The multiplex consists of 20 autosomal non-coding loci plus Amelogenin for sex determination, amplified in a single tube PCR reaction and visualised on the Applied Biosystems 3100 capillary electrophoresis (CE) system. Allele-specific primers tailed with shared universal tag sequences were designed to speed multiplex design and balance the amplification efficiencies of all loci through the use of a single reverse and two differentially labelled allele denoting forward universal primers. As the multiplex is intended for use with samples too degraded for conventional profiling, a computer program was specifically developed to aid interpretation. Critical factors taken into account by the software include empirically determined extremes of heterozygous imbalance (Hb) and the drop-out threshold (Ht) defined as the maximum peak height of a surviving heterozygous allele, where its partner may have dropped out. The discrimination power of the system is estimated at 1 in 4.5 million, using a White Caucasian population database. Comparisons using artificially degraded samples profiled with both the SNP multiplex and AMPFISTR SGM plus (Applied Biosystems) demonstrated a greater likelihood of obtaining a profile using SNPs for certain sample types. Saliva stains degraded for 147 days generated an 81% complete SNP profile whilst short tandem repeats (STRs) were only 18% complete; similarly blood degraded for 243 days produced full SNP profiles but only 9% with STRs. Reproducibility studies showed concordance between SNP profiles for different sample types, such as blood, saliva, semen and hairs, for the same individual, both within and between different DNA extracts.  相似文献   
20.
Since 1995 the Forensic Science Service (FSS) has carried out DNA profiling of reference samples for the UK National DNA Database and in forensic casework using two multiplex STR profiling systems. During this period, profiles with anomalous banding patterns, although comparatively rare, have been encountered regularly. The FSS has collected instances of triallelic patterns and aberrant diallelic patterns. A systematic examination of these patterns has provided insight into their underlying genetic cause. The triallelic patterns could be classified into two types based on the relative intensities of their component alleles. In the Type 1 pattern the alleles were of uneven intensity, whereas in the Type 2 pattern, all three alleles were of even intensity. Evidence is presented that the more frequent Type 1 pattern is the result of somatic mutation at a heterozygous locus, and the Type 2 pattern is the result of a localized chromosomal rearrangement at a heterozygous locus. Directly from the Type 1 pattern, it was possible to deduce the size difference between the progenitor and mutated allele. All mutational changes were found to be multiples of four nucleotides, suggesting the loss or addition of one or more tetrameric repeat units. Aberrant diallelic patterns were identified by analysts due to an unexpectedly large difference in intensity between alleles at a heterozygous locus. While some of these diallelic patterns are likely caused by the same genetic phenomena described above occurring at a homozygous locus, others are demonstrated to be caused by a mutation in the primer binding sequence, leading to a reduction in amplification efficiency of one allele. It is concluded that based on a visual inspection of a profile, it is possible to infer a likely genetic basis directly from the triallelic pattern. By contrast, the aberrant diallelic patterns can be due to any one of a number of possible genetic effects.  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