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691.
Michelle Wood Marleen Laloup Maria del Mar Ramirez Fernandez Kevin M. Jenkins Michael S. Young Jan G. Ramaekers Gert De Boeck Nele Samyn 《Forensic Science International Supplement Series》2005,150(2-3):227
We present a validated method for the simultaneous analysis of basic drugs which comprises a sample clean-up step, using mixed-mode solid-phase extraction (SPE), followed by LC–MS/MS analysis. Deuterated analogues for all of the analytes of interest were used for quantitation. The applied HPLC gradient ensured the elution of all the drugs examined within 14 min and produced chromatographic peaks of acceptable symmetry. Selectivity of the method was achieved by a combination of retention time, and two precursor-product ion transitions for the non-deuterated analogues. Oral fluid was collected with the Intercept®, a FDA approved sampling device that is used on a large scale in the US for workplace drug testing. However, this collection system contains some ingredients (stabilizers and preservatives) that can cause substantial interferences, e.g. ion suppression or enhancement during LC–MS/MS analysis, in the absence of suitable sample pre-treatment. The use of the SPE was demonstrated to be highly effective and led to significant decreases in the interferences. Extraction was found to be both reproducible and efficient with recoveries >76% for all of the analytes. Furthermore, the processed samples were demonstrated to be stable for 48 h, except for cocaine and benzoylecgonine, where a slight negative trend was observed, but did not compromise the quantitation. In all cases the method was linear over the range investigated (2–200 μg/L) with an excellent intra-assay and inter-assay precision (coefficients of variation <10% in most cases) for QC samples spiked at a concentration of 4, 12 and 100 μg/L. Limits of quantitation were estimated to be at 2 μg/L with limits of detection ranging from 0.2 to 0.5 μg/L, which meets the requirements of SAMHSA for oral fluid testing in the workplace. The method was subsequently applied to the analysis of Intercept® samples collected at the roadside by the police, and to determine MDMA and MDA levels in oral fluid samples from a controlled study. 相似文献
692.
Jan P. S. Fiselier 《Journal of Quantitative Criminology》1992,8(1):133-151
This paper tests the hypothesis of the stability of punishment as developed by Blumstein and his associates against Dutch prison data. After summarizing the existing empirical evidence, Dutch prison data are presented pertaining to the average daily population in penal institutions, on the one hand, and the number of admissions in these institutions, on the other hand. In three ways it is tested whether these data do support the hypothesis: regression analysis, Box-Jenkins analysis, and the analysis of a few dynamic models as presented by Berket al. (1981). The paper ends with discussing Blumstein's hypothesis and considers the way research into the extent of the prison population should be continued. 相似文献
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A new convention of ‘self-help housing’ has become established over the past 20 years. However, a close examination of the literature shows that this approach is not widely implemented, but remains largely at the level of showcase projects; moreover the lowest income groups are usually not the principal beneficiaries of sites-and-service schemes. The literature gives evidence of powerful political, administrative and economic interests against the large-scale legal delivery of sites-and-services, and in favour of the continued dependence of the poor on illegal access. 相似文献
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696.
Cecil E. Martin William E. Hefley David J. Bristow David Jan Steele 《Policy Sciences》1992,25(1):57-75
This paper addresses certain shortcomings of traditional acquisition approaches, especially for large-scale, unprecedented systems. Shortcomings in the requirements engineering processes are emphasized. We review incremental acquisition approaches and identify issues essential to successful application of incremental acquisition approaches to overcome these shortcomings.In identifying these issues, cases based on systems being developed by the Air Force Space Command are examined. They are the Granite Sentry (GS), Space Defense Operations Centers (SPADOC), and Mobile Command and Control System (MCCS) programs. Three key aspects of the lessons learned from these efforts parallel the steps suggested by a recent Air Force Studies Board report for reducing risk in developing unprecedented systems. These are team-based development, managing requirements uncertainty and change, and increased use of incremental acquisition approaches.This work was sponsored by the U.S. Department of Defense. Approved for public release, distribution unlimited. The views expressed in this article are those of the authors and do not reflect the official policy or position of the U.S. Air Force, the Department of Defense or the U.S. Government. 相似文献
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699.
Anise oil as para-methoxyamphetamine (PMA) precursor 总被引:1,自引:0,他引:1
These days, MDMA is one of the most popular drugs of abuse. Due to its illegality, MDMA and its chemical precursors are watched by governmental organizations in many countries. To avoid conflicts with legal instances, underground chemists have tried to market several new unregulated amphetamine analogues, such as 4-MTA. Para-methoxyamphetamine (PMA), on the other hand, is regulated by law but its precursors are easily obtained since they are cheap and unwatched. This article presents such a case, namely the large scale synthesis of PMA using anethole, a main constituent of anise oil, as precursor. Anethole has been converted to its phenyl acetone analogue via peracid oxidation, while PMA itself has been synthesized using this ketone as precursor in the Leuckart synthesis. The synthesis of PMA using anethole as starting product has been investigated applying GC/MS and GC-HSPME/MS techniques, hereby discovering new specific (4-methoxyphenol) and already identified synthesis impurities (4-methyl-5-(4-methoxyphenyl)pyrimidine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzyl methyl ketimine, 1-(4-methoxyphenyl)-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, 1-(4-methoxyphenyl)-N-methyl-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzaldimine). The new impurity 4-methoxyphenol is specific for the application of a peracid oxidation method where anethole is used as precursor. 相似文献
700.