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991.
Christopher J. Katilie BS Lauryn E. DeGreeff PhD Caitlin E. Sharpes MS Eric M. Best PhD Patricia E. Buckley PhD Jenna D. Gadberry BS Michele N. Maughan PhD 《Journal of forensic sciences》2023,68(6):2021-2036
While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel–oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material. 相似文献
992.
Applying a dynamic latent‐variable model to data on 148 policies collected over eight decades (1936–2014), we produce the first yearly measure of the policy liberalism of U.S. states. Our dynamic measure of state policy liberalism marks an important advance over existing measures, almost all of which are purely cross‐sectional and thus cannot be used to study policy change. We find that, in the aggregate, the policy liberalism of U.S. states steadily increased between the 1930s and 1970s and then largely plateaued. The policy liberalism of most states has remained stable in relative terms, though several states have shifted considerably over time. We also find surprisingly little evidence of multidimensionality in state policy outputs. Our new estimates of state policy liberalism have broad application to the study of political development, representation, accountability, and other important issues in political science. 相似文献
993.
994.
Food and health regulations are increasingly being pushed onto the political agenda, with rising concerns about genetically modified foods, obesity rates, and vaccination. Public beliefs and attitudes on these issues often conflict with the scientific evidence, yet we know relatively little about what influences opinion on these issues. The public lacks clear partisan cues, and many food and health attitudes cut across the ideological spectrum. We argue that these issues represent new ‘purity’ attitudes that are driven by the emotion of disgust. Across three studies, both by measuring individuals’ trait disgust sensitivity and experimentally inducing an emotional state of disgust, we demonstrate the impact of disgust on food and health policy attitudes. Our results show that greater sensitivity to disgust is associated with support for organic foods, opposition to genetically modified foods, and anti-vaccination beliefs. However, we find only limited evidence that experimentally manipulated disgust affects attitudes toward genetically modified and organic foods. Overall, our results demonstrate that disgust plays an important role in attitudes regarding public health and broadens our understanding of purity attitudes. 相似文献
995.
Those who turn out in American primary elections are a small and unrepresentative subset of the population. Why do citizens forgo participation in nominating contests yet vote in general elections? We argue that limited contact lowers participation in primary elections. We present results from a randomized field experiment with near 150,000 letters in California’s 2014 primary. Each letter went to one of the four million Californians who had participated in recent general elections but not in primaries. We find that a single letter increased turnout by 0.5 points from a base rate of 9.3 percent. This increase is more than twice the average effect calculated in a recent meta-analysis and represents a proportional increase of 5.4 percent. Our experiment shows that registrants who typically abstain from primaries—and who are thus often ignored by campaigns—can be effectively mobilized. 相似文献
996.
Standing as a candidate in public elections has been characterized as the ultimate act of political participation. We test the hypothesis that acquiring office within civil organizations increases the probability of becoming a candidate in public elections. In order to take self-selection problems into account, we provide quasi-experimental evidence using election discontinuities, in which we compare the likelihood of being nominated for public office between closely ranked winners and losers in Swedish student union (SU) elections. Our original data cover 5,000 SU candidates and register data on their candidacies in public elections (1991–2010). The analysis provides support to the hypothesis: Students elected to SU councils were about 34 percent (6 percentage points) more likely to become a candidate in a public election than SU council candidates who were not elected. The causal impact is fairly stable over time. The analysis makes important contributions to two interrelated bodies of literature: First, it provides political recruitment literature with causal evidence that acquiring leadership experiences at arenas outside of representative democratic institutions facilitate entry into election processes. Second, it provides strong evidence to an increasingly contested issue within political participation research by showing that certain organizational activities increase individuals’ political involvement. 相似文献
997.
Trust in state institutions is a prominent explanation of social trust. However, previous—mainly cross-sectional—analyses provide limited causal evidence regarding the relationship between institutional trust and social trust and it is thus essentially unknown whether an observed relationship reflects reverse causality (social trust forming institutional trust), or both forms of trust reflecting deep-seated dispositions (common confounding). Against the backdrop of the shortcomings of previous cross-sectional analyses, this paper utilizes two Danish panel surveys containing measures of both types of trust for the same individuals surveyed at multiple points in time over a long time-span (up to 18 years) to address the potentially reverse and/or spurious relationship. Using individual fixed effects and cross-lagged panel models, the results provide strong evidence of trust in state institutions exercising a causal impact on social trust, whereas the evidence for a reverse relationship is limited. 相似文献
998.
Scholars have reached mixed conclusions about the implications of increased political polarization for citizen decision-making. In this paper, we argue that citizens respond to ideological divergence with heightened affective polarization. Using a survey experiment conducted with a nationally representative sample of U.S. citizens, we find that increased ideological differences between political figures produce increasingly polarized affective evaluations, and that these differences are especially large among respondents with stronger ideological commitments and higher levels of political interest. We provide further support for these findings in an observational study of citizens’ evaluations of the U.S. Senators from their state. We also find that the polarizing effects of ideological differences can be largely mitigated with biographical information about the public officials, which suggests that the pernicious consequences of ideological polarization can be overcome by focusing on matters other than political disagreement. 相似文献
999.
Antoine J. Banks 《Political Behavior》2016,38(3):635-657
Research shows that group conflict sets ethnocentric thinking into motion. However, when group threat is not salient, can ethnocentrism still influence people’s political decision-making? In this paper, I argue that anger, unrelated to racial and ethnic groups, can activate the attitudes of ethnocentric whites and those that score low in ethnocentrism thereby causing these attitudes to be a stronger predictor of racial and immigration policy opinions. Using an adult national experiment over two waves, I induced several emotions to elicit anger, fear, or relaxation (unrelated to racial or ethnic groups). The experimental findings show that anger increases opposition to racial and immigration policies among whites that score high in ethnocentrism and enhances support for these policies among those that score low in ethnocentrism. Using data from the American National Election Study cumulative file, I find a similar non-racial/ethnic anger effect. The survey findings also demonstrate that non-racial/ethnic fear increases opposition to immigration among whites that don’t have strong out-group attitudes. 相似文献
1000.
To date, field experiments on campaign tactics have focused overwhelmingly on mobilization and voter turnout, with far more limited attention to persuasion and vote choice. In this paper, we analyze a field experiment with 56,000 Wisconsin voters designed to measure the persuasive effects of canvassing, phone calls, and mailings during the 2008 presidential election. Focusing on the canvassing treatment, we find that persuasive appeals had two unintended consequences. First, they reduced responsiveness to a follow-up survey among infrequent voters, a substantively meaningful behavioral response that has the potential to induce bias in estimates of persuasion effects as well. Second, the persuasive appeals possibly reduced candidate support and almost certainly did not increase it. This counterintuitive finding is reinforced by multiple statistical methods and suggests that contact by a political campaign may engender a backlash. 相似文献