全文获取类型
收费全文 | 585篇 |
免费 | 54篇 |
专业分类
各国政治 | 34篇 |
工人农民 | 25篇 |
世界政治 | 94篇 |
外交国际关系 | 58篇 |
法律 | 216篇 |
中国政治 | 7篇 |
政治理论 | 202篇 |
综合类 | 3篇 |
出版年
2023年 | 10篇 |
2022年 | 7篇 |
2021年 | 5篇 |
2020年 | 23篇 |
2019年 | 28篇 |
2018年 | 47篇 |
2017年 | 54篇 |
2016年 | 34篇 |
2015年 | 27篇 |
2014年 | 26篇 |
2013年 | 80篇 |
2012年 | 33篇 |
2011年 | 21篇 |
2010年 | 11篇 |
2009年 | 16篇 |
2008年 | 29篇 |
2007年 | 22篇 |
2006年 | 8篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 3篇 |
排序方式: 共有639条查询结果,搜索用时 62 毫秒
601.
Since the end of the Cold War, and particularly since September 11, 2001, the U.S. Government has substantially misunderstood its circumstances and has launched policies based on a compound error that has made those circumstances worse. The error consists of three parts: thinking the United States had more usable power after the Cold War when it had less; misreading the sources of apocalyptical terrorism; and failing to correct its misreading because of a bias set deep in its own political culture. Seeing the situation and the problems as they really are would lead to vast changes in both foreign and homeland security policies. 相似文献
602.
Liverpool Law Review - 相似文献
603.
The following study examines the reliability of physically matching fragments of bone and other mineral-based biological materials such as shells and teeth. Participants with varying education, training, and experience were asked to complete a matching exercise consisting of intentionally fragmented specimens. Success rates were very high; the positive association (correct match) rate was 0.925, while the nonassociation (overlooked match) rate was 0.075, and negative associations (incorrect matches) occurred at a rate of just 0.001. Results also indicate that those with more education and related experience tended to have higher positive association rates, although not significant statistically. Experienced osteologists, however, completed the matching exercise in significantly less time. Low error rates among both experienced and inexperienced individuals support the reliability and validity of performing physical matches of these materials, and suggest that performance may also be related to an individual's aptitude for spatial tasks or other factors. 相似文献
604.
605.
Adam G. Brown B.Sc. Daniel Sommerville B.Sc. Brian J. Reedy Ph.D. Ronald G. Shimmon Ph.D. Mark Tahtouh B.Sc. 《Journal of forensic sciences》2009,54(1):114-121
Abstract: Although the ability to develop latent fingerprints on paper using heat alone has been noted previously, it has been considered impractical for casework and inferior to other techniques. Here a new refinement of the technique is demonstrated for the high quality development of latent fingerprints on porous surfaces such as paper. Fingerprints deposited on various papers were developed by exposing them to hot air with a temperature in the vicinity of 300°C, for periods of c. 10–20 sec. Several different heating methods were tested. The novel observation was made that after shorter heating times, fluorescent prints could be observed. These became visible after longer heating times, as noted by earlier workers, but with greatly improved contrast compared with their results. Prints from various donors (and aged prints) were developed with excellent ridge contrast. Direct heating methods (such as with a hot plate or press) produced inferior results. The refined technique, which is simple, safe and inexpensive compared with conventional methods, has great potential for use in forensic laboratories. 相似文献
606.
This is the latest edition of Baker & McKenzie's column on developments in EU law relating to IP, IT and telecommunications. This article summarises recent developments that are considered important for practitioners, students and academics in a wide range of information technology, e-commerce, telecommunications and intellectual property areas. It cannot be exhaustive but intends to address the important points. This is a hard copy reference guide, but links to outside web sites are included where possible. No responsibility is assumed for the accuracy of information contained in these links. 相似文献
607.
As scientific understandings of genetics advance, researchers require increasingly rich datasets that combine genomic data from large numbers of individuals with medical and other personal information. Linking individuals' genetic data and personal information precludes anonymity and produces medically significant information--a result not contemplated by the established legal and ethical conventions governing human genomic research. To pursue the next generation of human genomic research and commerce in a responsible fashion, scientists, lawyers, and regulators must address substantial new issues, including researchers' duties with respect to clinically significant data, the challenges to privacy presented by genomic data, the boundary between genomic research and commerce, and the practice of medicine. This Article presents a new model for understanding and addressing these new challenges--a "public genomics" premised on the idea that ethically, legally, and socially responsible genomics research requires openness, not privacy, as its organizing principle. Responsible public genomics combines the data contributed by informed and fully consenting information altruists and the research potential of rich datasets in a genomic commons that is freely and globally available. This Article examines the risks and benefits of this public genomics model in the context of an ambitious genetic research project currently under way--the Personal Genome Project. This Article also (i) demonstrates that large-scale genomic projects are desirable, (ii) evaluates the risks and challenges presented by public genomics research, and (iii) determines that the current legal and regulatory regimes restrict beneficial and responsible scientific inquiry while failing to adequately protect participants. The Article concludes by proposing a modified normative and legal framework that embraces and enables a future of responsible public genomics. 相似文献
608.
609.
610.
Treatment of morphine, at room temperature, with a mixture of trifluoroacetic anhydride (TFAA) and acetic acid (20-30min) affords good yields of heroin. GC-MS and HPLC examination shows that heroin produced by this route to be extremely clean, but the product contains slightly less heroin than observed via the more traditional acetic anhydride (AA) route (76.1% versus 83.55%); and greater quantities of 3-MAM and 6-MAM (6.9% versus 0.75% and 7.13% versus 0.63%). The concentration ratios of the major alkaloid impurities were found to be both production method (TFAA and AA) as well as morphine extraction methodology dependant. Data contained herein describe the impact of this new production method on current intelligence efforts, largely by-passing existing heroin signature programs and the UNDCP's efforts to restrict access to key synthetic precursors. Given the methodology dependency we find that examination of the major alkaloid ratios is unsuitable for the development of a new heroin signature program. Further examination of the TFAA methodology allowed the identification of TFAA specific marker compounds, namely bis-trifluoroacetylmorphine (30), 3-trifluoroacetyl-6-acetylmorphine (31), 3-acetyl-6-trifluoroacetylmorphine (32) and trifluoroacetylcodeine (33). However, the hydrolytic lability of trifluroacetyl esters requires careful treatment of suspect samples, thus we propose a modification to existing HSP's in instances were the 6-MAM/WM ratio falls within the average minimum and maximum values of 6.17 and 17.32. 相似文献