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201.
This paper estimates risk reductions for each layer of security designed to prevent commercial passenger airliners from being commandeered by terrorists, kept under control for some time, and then crashed into specific targets. Probabilistic methods are used to characterize the uncertainty of rates of deterrence, detection, and disruption, as well as losses. Since homeland security decisionmakers tend to be risk‐averse because of the catastrophic or dire nature of the hazard or event, utility theory and Monte Carlo simulation methods are used to propagate uncertainties in calculations of net present value, expected utility, and probabilities of net benefit. We employ a “break‐even” cost‐benefit analysis to determine the minimum probability of an otherwise successful attack that is required for the benefit of security measures to equal their cost. In this context, we examine specific policy options: including Improvised Physical Secondary Barriers (IPSBs) in the array of aircraft security measures, including the Federal Air Marshal Service (FAMS), and including them both. Attack probabilities need to exceed 260 percent or 2.6 attacks per year to be 90 percent sure that FAMS is cost‐effective, whereas IPSBs have more than 90 percent chance of being cost‐effective even if attack probabilities are as low as 6 percent per year. A risk‐neutral analysis finds a policy option of adding IPSBs but not FAMS to the other measures to be preferred for all attack probabilities. However, a very risk‐averse decisionmaker is 48 percent likely to prefer to retain FAMS even if the attack probability is as low as 1 percent per year—a level of risk aversion exhibited by few, if any, government agencies. Overall, it seems that, even in an analysis that biases the consideration toward the opposite conclusion, far too much may currently be spent on security measures to address the problem of airline hijacking, and many spending reductions could likely be made with little or no consequent reduction of security. 相似文献
202.
Jules Stewart 《亚洲事务》2017,48(1):90-102
This article provides an overview of the development of the exploration, mapping and surveying of the frontier territories of India in the 19th century and the context of the Great Game with Russia. It pays particular attention to the Pundits, the native surveyors trained by British officers who made long surveying journeys into the borderlands of the Himalayas and Tibet. It gives an account of the explorations of pundits including Nain Singh, Kishen Singh, Sarat Chandra Das, Kintup, and Ugyen Gatso. 相似文献
203.
“Couplets” moves back and forth, swapping thought images, turns of phrase and story lines conjured up to get inside the machine and spread of a thing. Curiosity is a thought muscle throwing weight against fake foundations. The airs of a day make rhythm promises and labor demands. Paying attention is a starting point but no guarantee when there’s no floor. Things are happening. 相似文献
204.
The 2014 Scottish independence referendum settled little in terms of Scotland's constitutional future. The after-effects of what was the largest exercise in democracy in Scottish history certainly increased Scotland's devolved authority but, following withdrawal from the EU and with continuing differences and disagreements between the Westminster and Scottish governments, there have been increasing demands for a second referendum. One aspect of these conversations has been about the voting rights of Scots living outside Scotland, whose relationship with the nation would certainly be impacted by any successful vote for Scottish independence. And yet, they have had no voice in that decision and despite calls for their inclusion in any future vote, such inclusion remains unlikely. This article examines the reasons why such inclusion would be challenging and then considers what the Scottish diaspora think about Scottish independence and voting rights, by considering qualitative responses to a survey of members of the Scottish diaspora. 相似文献
205.
The main objectives of this article are to determine the prevalence of criminality among a sample of female African American drug users and to examine change in criminality over time, including the correlates associated with this change. Data were collected from 336 adult women who participated in an HIV risk-reduction intervention focused on the context of the women's daily life. Face-to-face structured interviews were conducted at baseline, prior to enrolling in the intervention, and at follow-up, 6 months after completion of the intervention. Bivariate and correlated multivariate methods were utilized to examine changes in criminality and other behaviors over time. Both violent and nonviolent criminality declined significantly between baseline and follow-up assessments. Of the correlates considered, drug-using characteristics and victimization played the greatest role in explaining the decrease in criminality. Low self-control and depressive symptoms also contributed to the reduction in criminality. The findings suggest the importance of considering individual characteristics that may influence the women's criminal behavior as well as the impact of their routine activities. 相似文献
206.
Although the benefits of the use of less lethal kinetic energy munitions are numerous, there is a need to evaluate the munitions prior to deployment to ensure their intended effect. The objective of the current research was to validate a surrogate that could be used to predict the risk of penetration of these devices. Existing data from biomechanical testing with post-mortem human specimens (PMHS) served as the foundation for this research. Development of the surrogate involved simulating the various layers of the skin and underlying soft tissues using a combination of materials. A standardized 12-gauge impactor was used to assess each combination. The energy density that resulted in a 50% risk of penetration for the anterior thorax region (23.99 J/cm(2)) from the previous research was matched using a specific combination of layers. Twelve various combinations of materials were tested with the 50% risk of penetration determined. The final validated surrogate consisted of a Laceration Assessment Layer (LAL) of natural chamois and .6 cm of closed-cell foam over a Penetration Assessment Layer (PAL) of 20% ordnance gelatin. This surrogate predicted a 50% risk of penetration at 23.88 J/cm(2). Injury risk curves for the PMHS and surrogate development work are presented. 相似文献
207.
Alex R. Piquero Jonathan Intravia Eric Stewart Nicole Leeper Piquero Marc Gertz Jake Bratton 《American Journal of Criminal Justice》2012,37(1):19-32
Theoretical and empirical consideration has long been given to the role of subcultural attitudes and how they relate to delinquency
and crime. Recently, Anderson has reconceptualized these early attitudinal depictions by considering the formation and role
of these specific attitudes or ‘code of the street’ among African-Americans in inner-city neighborhoods. A number of important
findings have emerged from this literature, yet much remains to be considered. We contribute to this literature in three specific
ways by examining: (1) the scope of street code attitudes across a wide variety of individuals—and not just inner-city African
American (males) to assess the generalizability of these attitudes; (2) the correlates of street code attitudes; and (3) the
extent to which street code attitudes mediate the relationship between various demographic and attitudinal (self-control)
variables and crime. Theoretical implications and directions for future research are addressed. 相似文献
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