全文获取类型
收费全文 | 973篇 |
免费 | 31篇 |
专业分类
各国政治 | 64篇 |
工人农民 | 20篇 |
世界政治 | 117篇 |
外交国际关系 | 90篇 |
法律 | 401篇 |
中国政治 | 9篇 |
政治理论 | 282篇 |
综合类 | 21篇 |
出版年
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 26篇 |
2016年 | 32篇 |
2015年 | 23篇 |
2014年 | 13篇 |
2013年 | 182篇 |
2012年 | 20篇 |
2011年 | 29篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 29篇 |
2007年 | 28篇 |
2006年 | 38篇 |
2005年 | 40篇 |
2004年 | 37篇 |
2003年 | 41篇 |
2002年 | 33篇 |
2001年 | 14篇 |
2000年 | 20篇 |
1999年 | 21篇 |
1998年 | 14篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 12篇 |
1994年 | 13篇 |
1993年 | 15篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 9篇 |
1989年 | 13篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 20篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 14篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 7篇 |
1974年 | 6篇 |
1969年 | 4篇 |
1968年 | 4篇 |
排序方式: 共有1004条查询结果,搜索用时 15 毫秒
141.
Kavlick MF Lawrence HS Merritt RT Fisher C Isenberg A Robertson JM Budowle B 《Journal of forensic sciences》2011,56(6):1457-1463
Successful mitochondrial DNA (mtDNA) forensic analysis depends on sufficient quantity and quality of mtDNA. A real-time quantitative PCR assay was developed to assess such characteristics in a DNA sample, which utilizes a duplex, synthetic DNA to ensure optimal quality assurance and quality control. The assay's 105-base pair target sequence facilitates amplification of degraded DNA and is minimally homologous to nonhuman mtDNA. The primers and probe hybridize to a region that has relatively few sequence polymorphisms. The assay can also identify the presence of PCR inhibitors and thus indicate the need for sample repurification. The results show that the assay provides information down to 10 copies and provides a dynamic range spanning seven orders of magnitude. Additional experiments demonstrated that as few as 300 mtDNA copies resulted in successful hypervariable region amplification, information that permits sample conservation and optimized downstream PCR testing. The assay described is rapid, reliable, and robust. 相似文献
142.
DNA-based analysis is integral to missing person identification cases. When direct references are not available, indirect relative references can be used to identify missing persons by kinship analysis. Generally, more reference relatives render greater accuracy of identification. However, it is costly to type multiple references. Thus, at times, decisions may need to be made on which relatives to type. In this study, pedigrees for 37 common reference scenarios with 13 CODIS STRs were simulated to rank the information content of different combinations of relatives. The results confirm that first-order relatives (parents and fullsibs) are the most preferred relatives to identify missing persons; fullsibs are also informative. Less genetic dependence between references provides a higher on average likelihood ratio. Distant relatives may not be helpful solely by autosomal markers. But lineage-based Y chromosome and mitochondrial DNA markers can increase the likelihood ratio or serve as filters to exclude putative relationships. 相似文献
143.
Likelihood ratios are necessary to properly interpret mixed stain DNA evidence. They can flexibly consider alternate hypotheses and can account for population substructure. The likelihood ratio should be seen as an estimate and not a fixed value, because the calculations are functions of allelic frequency estimates that were estimated from a small portion of the population. Current methods do not account for uncertainty in the likelihood ratio estimates and are therefore an incomplete picture of the strength of the evidence. We propose the use of a confidence interval to report the consequent variation of likelihood ratios. The confidence interval is calculated using the standard forensic likelihood ratio formulae and a variance estimate derived using the Taylor expansion. The formula is explained, and a computer program has been made available. Numeric work shows that the evidential strength of DNA profiles decreases as the variation among populations increases. 相似文献
144.
This study offers the first research data on the interest of divorcing parents in marital reconciliation. A sample of 2,484 divorcing parents was surveyed after taking required parenting classes. They were asked about whether they believed their marriage could still be saved with hard work, and about their interest in reconciliation services. About 1 in 4 individual parents indicated some belief that their marriage could still be saved, and in about 1 in 9 matched couples both partners did. As for interest in reconciliation services, about 3 in 10 individuals indicated potential interest. In a sub‐sample of 329 matched couples, about 1 in 3 couples had one partner interested but not the other, and in 1 in 10 couples both partners were interested in reconciliation services. Findings were consistent across most demographic and marital factors. The only strong predictors of reconciliation interest were gender, with males being more interested than females, and initiator status, with far greater interest among those whose partner initiated the divorce. These findings are discussed in terms of attachment theory and future prospects of divorce services. 相似文献
145.
The recent financial crisis has provoked a raft of contending claims as to whether the cause of the crisis is better attributed to market failure or political failure. Such claims are predicated on a presumption that markets and polities are meaningfully separate entities. To the contrary, we argue that contemporary arrangements create an entangled political economy that renders theorizing based on separation often misleading. Within this alternative framework of entangled political economy, we illuminate both the recent Troubled Assets Relief Program (TARP) and the New Deal??s National Recovery Administration (NRA). 相似文献
146.
Marian C Anghel A Bel SM Ferencz BK Ursoniu S Dressler M Popescu O Budowle B 《Forensic science international》2007,170(1):73-75
Allele frequencies for the 15 tetranucleotide short tandem repeat loci contained in the AmpFlSTR Identifiler kit were obtained from a population sample of 219 unrelated individuals born in the western part of Romania. 相似文献
147.
Martinez-Gonzalez LJ Lorente JA Martinez-Espin E Alvarez JC Lorente M Villanueva E Budowle B 《Journal of forensic sciences》2007,52(2):397-399
We report a case where an alleged father (AF) attempted to substitute someone else's saliva sample for his reference sample in a paternity analysis. Buccal cells were collected from the AF and the child, and DNA analysis was performed using an autosomal STR loci (Identifiler). The profile from the AF showed extra peaks in some loci, as well as a much higher "X" allele peak relative to the "Y" allele peak at the amelogenin locus. After conducting reanalysis by another technician with another set of positive and negative controls, it was concluded that the only source of the mixed profile was by intentional introduction by the AF, at the time of sampling, of some foreign human biological material, most likely saliva from a woman. Owing to the inconclusive results, when the AF was called back to the lab and the peculiar results were explained to him, he admitted that he had introduced into his mouth saliva from another person in an attempt to be excluded as the father of the child. Although tampering with DNA reference samples is not common, some individuals may attempt to contaminate or otherwise adulterate specimens before DNA tests. Personnel responsible for sampling should be aware of this possibility and should try to establish procedures to avoid the problem. 相似文献
148.
Dirk T. Van Der Meer D.M.D. Paula C. Brumit D.D.S. Bruce A. Schrader D.D.S. Stephen B. Dove D.D.S. M.S. David R. Senn D.D.S. 《Journal of forensic sciences》2010,55(6):1499-1503
Abstract: An online forensic dental identification exercise was conducted involving 24 antemortem–postmortem (AM–PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM–PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT‐ID index = 0.923) and Spearman’s rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer‐aided dental identification allows for an objective comparison of AM–PM radiographs and can be a useful tool to support a forensic dental identification conclusion. 相似文献
149.
Ushtana Antia M.Sc. Malcolm D. Tingle Ph.D. Bruce R. Russell Ph.D. 《Journal of forensic sciences》2010,55(5):1311-1318
Abstract: An LC–MS method was developed for benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP), constituents of “party pills” or “legal herbal highs,” and their metabolites in human blood plasma. Compounds were resolved using a mixture of ammonium formate (pH 4.5, 0.01 M) and acetonitrile (flow rate of 1.0 mL/min) with a C18 column. Calibration curves were linear from 1 to 50 ng/mL (R2 > 0.99); the lower limit of quantification (LLOQ) was 5 ng/mL; the accuracy was >90%; the intra‐ and interday relative standard deviations (R.S.D) were <5% and <10%, respectively. Human plasma concentrations of TFMPP were measured in blood samples taken from healthy adults (n = 6) over 24 h following a 60‐mg oral dose of TFMPP: these peaked at 24.10 ng/mL (±1.8 ng/mL) (Cmax) after 90 min (Tmax). Plasma concentrations of 1‐(3‐trifluoromethyl‐4‐hydroxyphenyl) piperazine peaked at 20.2 ng/mL (±4.6 ng/mL) after 90 min. TFMPP had two disposition phases (t½ = 2.04 h (±0.19 h) and 5.95 h (±1.63 h). Apparent clearance (Cl/F) was 384 L/h (±45 L/h). 相似文献
150.
In this study, we randomly assigned 123 sixth and seventh grade classrooms from seven middle schools in the greater Cleveland
area to one of two five-session curricula addressing gender violence/sexual harassment (GV/SH) or to a no-treatment control
group. A baseline survey and two follow-up surveys were administered immediately after the treatment (Wave 2) and about six
months post-treatment (Wave 3). In an earlier paper, we demonstrated the effectiveness of two approaches to youth GV/SH prevention
programming (a fact-based, law and justice curriculum and an interaction-based curriculum). In this paper, we explored whether
these largely positive findings remain for both girls and boys, including whether girls experience higher levels of GV/SH
than boys. Most of our statistical models proved to be non-statistically significant. However, in 2 of our 48 victimization/perpetration
(any violence, sexual violence and non-sexual violence) models (across two post-intervention follow-up points), we observed
that the interventions reduced peer (male or female, non-dating partner) sexual violence victimization and reduced peer perpetration,
but another outcome model indicated that the interventions increased dating perpetration. These mixed findings will need to
be explored further in future research. Regarding our primary research question, we observed no statistically significant
differences for the treatment multiplied by gender interaction terms for any of the perpetration or victimization outcome
models, suggesting that the treatment had similar effects on girls and boys. However, we did observe that boys are more involved
in violence than girls: both as victims and perpetrators. Boys experienced significantly more of three types of victimization
from peers and dating partners compared to what girls experienced at the hands of their peers and dating partners. As perpetrators,
boys committed more sexual victimization against peers (immediately post-intervention only) and more sexual victimization
against dating partners than girls. The implications of these results are discussed. 相似文献