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91.
In a double-blind placebo controlled study on psychomotor skills important for car driving (Study 1), a 75 mg dose of +/- 3,4-methylenedioxymethamphetamine (MDMA) was administered orally to 12 healthy volunteers who were known to be recreational MDMA-users. Toxicokinetic data were gathered by analysis of blood, urine, oral fluid and sweat wipes collected during the first 5h after administration. Resultant plasma concentrations varied from 21 to 295 ng/ml, with an average peak concentration of 178 ng/ml observed between 2 and 4h after administration. MDA concentrations never exceeded 20 ng/ml. Corresponding MDMA concentrations in oral fluid, as measured with a specific LC-MS/MS method (which required only 50 microl of oral fluid), generally exceeded those in plasma and peaked at an average concentration of 1215 ng/ml. A substantial intra- and inter-subject variability was observed with this matrix, and values ranged from 50 to 6982 ng/ml MDMA. Somewhat surprisingly, even 4-5h after ingestion, the MDMA levels in sweat only averaged 25 ng/wipe. In addition to this controlled study, data were collected from 19 MDMA-users who participated in a driving simulator study (Study 2), comparing sober non-drug conditions with MDMA-only and multiple drug use conditions. In this particular study, urine samples were used for general drug screening and oral fluid was collected as an alternative to blood sampling. Analysis of oral fluid samples by LC-MS/MS revealed an average MDMA/MDEA concentration of 1121 ng/ml in the MDMA-only condition, with large inter-subject variability. This was also the case in the multiple drug condition, where generally, significantly higher concentrations of MDMA, MDEA and/or amphetamine were detected in the oral fluid samples. Urine screening revealed the presence of combinations such as MDMA, MDEA, amph, cannabis, cocaine, LSD and psilocine in the multiple-drug condition.  相似文献   
92.
Existential anxiety is hypothesized to be a core human issue in a great deal of theoretical and philosophical writing. However, little is known about the emergence of these concerns and their relation to emotional functioning in youth. The purpose of this study was to examine the phenomenon of existential anxiety in a sample of adolescents. Data on existential concerns, identity development and psychological symptoms were collected on a sample of 139 youth in grades 9–12. Results indicated that existential anxiety concerns have a theoretically consistent factor structure, are common among adolescents, and are associated with psychological symptoms, as well as identity issues. Results are discussed with regard to the importance of existential concerns in the lives of youth and the need for additional research.Received PhD from Florida International University. Interests are identity development including associated anxiety and distress, cross-national comparisons, and the development of identity interventions.Received PhD from Florida International University. Interests focus on the developmental psychopathology of anxiety and depression.Received PhD from the University of Arizona. Interests include a range of topics in developmental psychopathology, prevention, program evaluation, and research methodology.  相似文献   
93.
Drawing on recent insights in the nationalism and citizenship regime literatures, this article develops a macrotheoretical framework for understanding cross-national variations in tolerance of ethnic minorities. Specifically, it tests the hypothesis that the degree to which the dominant ethnic tradition or culture is institutionalized in the laws and policies of a nation-state affects citizen tolerance of ethnic minorities. Employing a multilevel regression model, it systematically tests the framework, as well as competing individual and country-level explanations, for all member states of the European Union in 1997. Results confirm a strong relationship between the laws governing the acquisition and expression of citizenship, that is, citizenship regime type, and individual tolerance judgments. Moreover, citizenship regime type has a strong mediating effect on three individual-level variables previously shown to predict tolerance: ingroup national identity, political ideology, and satisfaction with democracy.  相似文献   
94.
In 2006, the Public Choice Society chose a new president using approval voting. There were five candidates, and the election was extremely close. We indicate the sources of support of the different candidates, based in part on spectral analysis, by voters who cast between one and five votes. Using preference information that was also gathered, we show that two candidates different from the approval voting winner, including the apparent Condorcet winner, might have won under different voting systems. Because most voters did not indicate their complete preference rankings, however, these differences are hardly robust, especially since the outcome was essentially a dead heat.  相似文献   
95.
As the debates over cloning and stem cell research indicate, issues raised by biotechnology combine research into the genetic sciences, perspectives and contexts articulated by the social sciences, and the ethical and anthropological concerns of philosophy. Consequently, we argue that intervening in the debates over biotechnology require supradisciplinary critical philosophy and social theory to illuminate the problems and their stakes. More specifically, we will demonstrate problems with the cloning of animals that for now render the cloning of humans unacceptable. In addition, we take on arguments for and against stem cell research and contend that it contains positive potential for medical advances that should not be blocked by problematic conservative positions. Nonetheless, we believe that the entire realm of biotechnology is fraught with dangers and problems that require careful study and democratic debate of key ethical and political issues.  相似文献   
96.
We investigated the relation between urban psychosocial stressors and intimacy achievement in a sample of 59 African American, Hispanic American, and White adolescent fathers-to-be. Participants received an intimacy score based on Orlofsky's Intimacy Status Rating Scale. Those with higher cumulative psychosocial stressors had lower levels of intimacy. One psychosocial risk factor, low interpersonal empathy, was significantly associated with intimacy levels. African Americans had lower levels of intimacy than Hispanic or White participants.  相似文献   
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99.
Since the 1970s, a wide body of research has suggested that the accuracy of clinical risk assessments of violence might be increased if clinicians used actuarial tools. Despite considerable progress in recent years in the development of such tools for violence risk assessment, they remain primarily research instruments, largely ignored in daily clinical practice. We argue that because most existing actuarial tools are based on a main effects regression approach, they do not adequately reflect the contingent nature of the clinical assessment processes. To enhance the use of actuarial violence risk assessment tools, we propose a classification tree rather than a main effects regression approach. In addition, we suggest that by employing two decision thresholds for identifying high- and low-risk cases--instead of the standard single threshold--the use of actuarial tools to make dichotomous risk classification decisions may be further enhanced. These claims are supported with empirical data from the MacArthur Violence Risk Assessment Study.  相似文献   
100.
Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.  相似文献   
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