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231.
Postmortem stability of DNA   总被引:11,自引:0,他引:11  
High-molecular-weight DNA was recovered postmortem in sufficient quantities from various human organ tissues as well as from blood, although not all organs were equally well suitable. Good DNA stability was found in brain cortex, lymph nodes and psoas muscle over a period of three weeks postmortem. Spleen and kidney showed good DNA stability up to five days postmortem but after longer periods, rapid degradation was observed. Yields of DNA from blood were not consistent because of the non homogeneity of samples. Blood clots were rich with DNA. Generally, the amount of degraded DNA correlated directly with the duration of the postmortem period. However in some cases, DNA degradation was already prominent after a short period. However in some cases, DNA degradation was already prominent after a short period. Case histories showed that high environmental temperature at the site of death and/or infectious diseases prior to death were the main factors for rapid autolysis. Gradual disappearance to complete loss of the long fragments (15-23 kb) was observed in DNA fingerprinting using the minisatellite probe 33.15. No extra-bands were noted, thus excluding erroneous conclusions. However, evidentiary value of older samples was lower.  相似文献   
232.
Hopelessness is implicated in multiple psychological disorders. Little is known, however, about the trajectory of hopelessness during adolescence or how emergent future orientation may influence its trajectory. Parallel process latent growth curve modelling tested whether (i) trajectories of future orientation and hopelessness and (ii) within-individual change in future orientation and hopelessness were related. The study was comprised of 472 adolescents [52% female, 47% Caucasian, 47% received free lunch] recruited at ages 12–13 who completed measures of future orientation and hopelessness at five annual assessments. The results indicate that a general decline in hopelessness across adolescence occurs quicker for those experiencing faster development of future orientation, when controlling for age, sex, low socio-economic status in addition to stressful life events in childhood and adolescence. Stressful childhood life events were associated with worse future orientation at baseline and negative life events experienced during adolescence were associated with both an increase in the trajectory of hopelessness as well as a decrease in the trajectory of future orientation. This study provides compelling evidence that the development of future orientation during adolescence is associated with a faster decline in hopelessness.  相似文献   
233.
Adolescent self-regulation is increasingly seen as an important predictor of sexual risk-taking behaviors, but little is understood about how changes in self-regulation affect later sexual risk-taking. Family financial stress may affect the development of self-regulation and later engagement in sexual risk-taking. We examined whether family financial stress influences self-regulation in early adolescence (age 13) and growth in self-regulation throughout adolescence (from age 13–17 years). We then assessed the effects of family financial stress, baseline self-regulation, and the development of self-regulation on adolescent sexual risk-taking behaviors at age 18 years. Using a curve-of-factors model, we examined these relationships in a 6-year longitudinal study of 470 adolescents (52% female) and their parents from a large northwestern city in the United States. Results indicated that family financial stress was negatively associated with baseline self-regulation but not with growth in self-regulation throughout adolescence. Both baseline self-regulation and growth in self-regulation were predictive of decreased likelihood of engaging in sexual risk-taking. Family financial stress was not predictive of later sexual risk-taking. Intervening to support the development of self-regulation in adolescence may be especially protective against later sexual risk-taking.  相似文献   
234.
An extensive body of research documents how governing parties generally suffer electoral defeats. Varying explanations have been offered, most of which touch upon the liabilities of policy responsibility. Although media coverage is generally acknowledged as one of these liabilities, few empirical studies have examined how news content affect government support. Based on the fact that voters get their information about politics, policies and societal issues from the media, this article studies how the constant stream of negative news influences incumbent support over a 20-year period in Denmark. Modeling a previously untested argument on the cost of ruling, it shows that the accumulation of bad news throughout tenure exerts a substantial effect on government support.  相似文献   
235.
There is an ongoing debate among practitioners and scholars about the security consequences of transnational migration. Yet, existing work has not, so far, fully taken into account the policy instruments states have at their disposal to mitigate these risks, and reliable evidence is lacking for the effectiveness of such measures. This article addresses both shortcomings as whether and to what extent national migration policies affect the diffusion of terrorism via population movements are analysed. Spatial analyses report robust support for a moderating influence of states’ policies: while terrorism can travel from one country to another via larger migration populations, this only applies to target countries with extremely lax regulations and control mechanisms. This research sheds new light on the security implications of population movements, and it crucially adds to our understanding of governments’ instruments for addressing migration challenges as well as their effectiveness.  相似文献   
236.
Innovating upon previous field experiments and theories of identity‐based discrimination, we test whether public officials are using searches (“identity‐questing”) to profile citizens and acting on latent biases. Pairs of “institutional” and “noninstitutional” requesters send lower and moderate burden freedom of information (FOI) requests—providing no identity cues apart from undistinctive names, e‐mails, and ID numbers—to nearly 700 of Brazil's largest municipalities. Results show institutional requesters receive one‐fifth more responses than noninstitutional comparators. For moderate versus lower burden requests, noninstitutional requesters are 11% less likely to receive a compliant response than their institutional comparators. The only plausible explanation for these results is identity‐questing, a phenomenon that has far‐reaching policy implications. Most of the world's FOI laws, for example, contain vague ID obligations, which translate incoherently from laws to regulation and practice. Results enjoin public service providers to protect the identities of citizens by default or upon request.  相似文献   
237.
Amidst calls for more scrutiny of the failure of infrastructure public–private partnerships (PPPs), uncertainty about how we can measure failure remains, and little systematic evidence illuminates its likelihood. Our mixed‐methods design explores the notion of failure and identifies the conditions under which it happens. The first phase of our research employs documentary analysis and semistructured expert interviews, and identifies project cancellation as capturing the most severe occurrences of failure. A second phase statistically analyzes a unique World Bank data set capturing the provisions of over 4,000 infrastructure PPPs launched between 1990 and 2015 in 89 countries. We find robust evidence supporting the theoretical claim that PPPs are less likely to be canceled in countries with more veto points among their political institutions to restrain politicians from intervening in policy implementation. Cancellation is a rare, but valid indicator of failure, and the importance of veto players clarifies how political risk operates in this context.  相似文献   
238.

China’s rise as a global power corresponded with a diminution of Taiwanese diplomacy, which has left Central America as the last region to host a continuous bloc of countries that recognize the ROC. In this article, we argue that China’s success in gaining diplomatic recognition from Taiwan’s former allies has largely resulted from China's economic policy, specifically its promises of large-scale infrastructure projects and the integration of Central American economies with Chinese markets. However, there are limits to how far China has advanced in gaining full recognition from the region. The competing political and economic interests of China, Taiwan, the United States, and the Central American countries themselves, continue to influence patterns of diplomatic switching. More specifically, we argue that the threat of punitive measures from the United States combined with a turn in Taiwanese diplomacy toward assistance efforts to combat Covid-19 may deter future switching in the short to medium-term. Our analysis offers case studies of four Central American countries (Costa Rica, Panama, El Salvador and Nicaragua) to illustrate the multi-year processes by which China’s economic strategy leads to diplomatic switching and examine the paths ahead for the remaining holdouts facing the prospect of economic and political penalties by the United States.

  相似文献   
239.
Several developing countries are currently experiencing a significant fertility decline, however, academic economists have paid little attention to this transition. This paper seeks to explain the fertility transition by infant mortality, urbanisation, income, culture and educational attainment of females and males using annual data for 92 developing countries over the period 1960–2014. External instruments are used to deal with endogeneity. The results suggest that increasing per capita income, improved female education and increasing secularisation have been important determinants for declining fertility in the developing world.  相似文献   
240.
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