全文获取类型
收费全文 | 686篇 |
免费 | 50篇 |
专业分类
各国政治 | 56篇 |
工人农民 | 29篇 |
世界政治 | 82篇 |
外交国际关系 | 30篇 |
法律 | 373篇 |
中国政治 | 5篇 |
政治理论 | 156篇 |
综合类 | 5篇 |
出版年
2024年 | 1篇 |
2023年 | 14篇 |
2021年 | 14篇 |
2020年 | 22篇 |
2019年 | 25篇 |
2018年 | 21篇 |
2017年 | 32篇 |
2016年 | 37篇 |
2015年 | 28篇 |
2014年 | 33篇 |
2013年 | 136篇 |
2012年 | 44篇 |
2011年 | 36篇 |
2010年 | 21篇 |
2009年 | 14篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 23篇 |
2005年 | 22篇 |
2004年 | 25篇 |
2003年 | 24篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 16篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有736条查询结果,搜索用时 15 毫秒
221.
Colby E. Ott M.S. Kourtney A. Dalzell B.S. Pedro José Calderón-Arce M.S. Ana Lorena Alvarado-Gámez Ph.D. Tatiana Trejos Ph.D. Luis E. Arroyo Ph.D. 《Journal of forensic sciences》2020,65(6):1935-1944
The increasing demand for rapid methods to identify both inorganic and organic gunshot residues (IGSR and OGSR) makes electrochemical methods, an attractive screening tool to modernize current practice. Our research group has previously demonstrated that electrochemical screening of GSR samples delivers a simple, inexpensive, and sensitive analytical solution that is capable of detecting IGSR and OGSR in less than 10 min per sample. In this study, we expand our previous work by increasing the number of GSR markers and applying machine learning classifiers to the interpretation of a larger population data set. Utilizing bare screen-printed carbon electrodes, the detection and resolution of seven markers (IGSR; lead, antimony, and copper, and OGSR; nitroglycerin, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite) was achieved with limits of detection (LODs) below 1 µg/mL. A large population data set was obtained from 395 authentic shooter samples and 350 background samples. Various statistical methods and machine learning algorithms, including critical thresholds (CT), naïve Bayes (NB), logistic regression (LR), and neural networks (NN), were utilized to calculate the performance and error rates. Neural networks proved to be the best predictor when assessing the dichotomous question of detection of GSR on the hands of shooter versus nonshooter groups. Accuracies for the studied population were 81.8 % (CT), 88.1% (NB), 94.7% (LR), and 95.4% (NN), respectively. The ability to detect both IGSR and OGSR simultaneously provides a selective testing platform for gunshot residues that can provide a powerful field-testing technique and assist with decisions in case management. 相似文献
222.
International non‐governmental organisations (INGOs) are prominent actors in the international arena, aiming to improve the life of disadvantaged people. However, INGOs often do not succeed in doing this. Consequently, INGO legitimacy is regularly questioned. Increased transparency and tightened accountability mechanisms are often‐mentioned solutions to this problem. Based on an analysis of four dimensions of INGO legitimacy—normative, regulatory, cognitive and output legitimacy—we argue that this is not necessarily adequate. We conclude that INGO mission statements create a normative source of legitimacy, but that this, in itself, is not enough to ground INGO legitimacy: it also needs to be institutionalised and organised. However, as a result of power relations and resulting pressures for accountability and transparency, as defined by their external stakeholders, INGOs experience a permanent struggle to reconcile their mission with the requirements for regulatory, cognitive and output legitimacy. The more these stakeholders press for increased organisation of INGO work, the more the pursuit of the core objectives of INGOs is obstructed. We illustrate this argument with the case of the post‐Tsunami humanitarian intervention (2004/2005). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
223.
Marcus André Melo 《拉美政治与社会》2007,49(4):115-148
Current explanations of taxation levels have identified a host of factors, such as levels of economic development and GDP per capita, tax handles, tax morale, and political regimes. But none of them can account for Argentina's exceptionalism. Using a "transaction cost politics" approach and the case of Brazil for comparison, this article argues that the key to explaining low taxation in Argentina is political instability. Systemic instability affects the tax behavior of governments. Facing an uncertain future, incumbent governments choose to extract resources from society through inflation rather than normal taxation. This article argues that political institutions, particularly federalism, contribute to instability and thereby reduce the discount rates of government policymakers. 相似文献
224.
André Kaiser 《Politische Vierteljahresschrift》2007,48(1):119-135
Ohne Zusammenfassung 相似文献
225.
226.
227.
Age at death assessment of adult skeletons is one of the most difficult problems in forensic and physical anthropology. Two fundamental sources of error are described: the complex variability in the process of skeletal aging and methodological bias. Taking into account these limits, we developed a new scoring system for the auricular surface of the ilium and the pubic symphysis. In order to address a large variability, we examine reference samples from Europe, North America, Africa, and Asia. Data were processed using Bayesian prediction in order to classify specimens in age range categories. Results show that combining indicators do not perform better than the auricular surface used as a single indicator. Morphological changes with aging are variable between Asian, African, and European populations, confirming the necessity to use population-specific standards. Bayesian prediction produces reliable classification and is applicable for subjects over 50 years old, a real methodological improvement. 相似文献
228.
229.
Telmon N Gaston A Chemla P Blanc A Joffre F Rougé D 《Journal of forensic sciences》2005,50(3):507-512
Age determination is a major field of interest in forensic anthropology. Among the different methods based on macroscopic skeletal study, the Suchey-Brooks method, which analyzes the pubic symphysis, is one of the most reliable. We applied the Suchey-Brooks method to three-dimensional computed tomographic reconstructions of the pubic symphysis. We demonstrated excellent agreement between the results of analysis of bone samples and those of the three-dimensional images, in particular regarding ridges of the articular surface and delimitation of the extremities. The accuracy of age estimation did not significantly differ (Wilcoxon test) between the Suchey-Brooks method applied to bones and the same method applied to CT images. Using high-quality images, this approach seems as reliable as the standard Suchey-Brooks method and offers several advantages: no bone preparation, no damage to bone material, and the possibility of application to living individuals. 相似文献
230.
Pinheiro MF Cainé L Pontes L Abrantes D Lima G Pereira MJ Rezende P 《Forensic science international》2005,148(2-3):221-223
Allele frequencies of sixteen autossomal short tandem repeats (STRs), D3S1358, VWA, D16S539, D8S1179, D21S11, D18S51, TH01, FGA, D5S818, D13S317, D7S820, TPOX, CSF1PO, Penta D, Penta E (included in the PowerPlex 16 kit), and the SE33 (PowerPlex ES Monoplex System SE33) were determined in a sample of 200 healthy unrelated individuals from the north of Portugal. 相似文献