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971.
972.

Objectives

Researchers have used repeated cross sectional observations of homicide rates and sanctions to examine the deterrent effect of the adoption and implementation of death penalty statutes. The empirical literature, however, has failed to achieve consensus. A fundamental problem is that the outcomes of counterfactual policies are not observable. Hence, the data alone cannot identify the deterrent effect of capital punishment. This paper asks how research should proceed. We seek to make transparent how assumptions shape inference.

Methods

We study the identifying power of relatively weak assumptions restricting variation in treatment response across places and time. We perform empirical analysis using state-level data in the United States in 1975 and 1977.

Results

The results are findings of partial identification that bound the deterrent effect of capital punishment. Under the weakest restrictions, there is substantial ambiguity: we cannot rule out the possibility that having a death penalty statute substantially increases or decreases homicide. This ambiguity is reduced when we impose stronger assumptions, but inferences are sensitive to the maintained restrictions.

Conclusions

Imposing certain assumptions implies that adoption of a death penalty statute increases homicide, but other assumptions imply that the death penalty deters it. Thus, society at large can draw strong conclusions only if there is a consensus favoring particular assumptions. Without such a consensus, data on sanctions and murder rates cannot settle the debate about deterrence. However, data combined with weak assumptions can bound and focus the debate.  相似文献   
973.
This paper analyzed the existing literature on risk and protective factors for intimate partner violence among Hispanics using the four-level social-ecological model of prevention. Three popular search engines, PsycINFO, PubMed, and Google Scholar, were reviewed for original research articles published since the year 2000 that specifically examined factors associated with intimate partner violence (IPV) among Hispanics. Factors related to perpetration and victimization for both males and females were reviewed. Conflicting findings related to IPV risk and protective factors were noted; however, there were some key factors consistently shown to be related to violence in intimate relationships that can be targeted through prevention efforts. Future implications for ecologically-informed research, practice, and policy are discussed.  相似文献   
974.
We describe sibling proactive and reactive aggression in middle and late adolescence. Participants were 8th (n?=?303, M age?=?13.74 years, SD?=?.59) and 12th (n?=?300, M age?=?17.73 years, SD?=?.56) grade adolescents who completed an in-school survey. Findings revealed that these adolescents were significantly more likely to engage in reactive than proactive aggression with their closest-aged sibling. However, 8th grade adolescents reported greater aggression toward their closest-aged sibling than did 12th grade adolescents. In addition, sex composition of the sibling dyad moderated the association between sibling relationship quality (i.e., warmth and rivalry) and both proactive and reactive aggression indicating unique links for brother-brother and older sister-younger brother pairs.  相似文献   
975.
976.
Explanations for the incumbency advantage in American elections have typically pointed to the institutional advantages that incumbents enjoy over challengers but overlook the role of individual traits that reinforce this bias. The institutional advantages enjoyed by incumbents give voters more certainty about who incumbents are and what they might do when (and if) they assume office. We argue that these institutional advantages make incumbents particularly attractive to risk-averse individuals, who shy away from uncertainty and embrace choices that provide more certainty. Using data from 2008 and 2010 Cooperative Congressional Election Study, we show that citizens who are more risk averse are more likely to support incumbent candidates, while citizens who are more risk accepting are more likely to vote for challengers. The foundations of the incumbency advantage, we find, lie not only in the institutional perks of office but also in the individual minds of voters.  相似文献   
977.
This study examines the community‐wide effects of two statewide early childhood policy initiatives in North Carolina. One initiative provides funding to improve the quality of child care services at the county level for all children between the ages of 0 to 5, and the other provides funding for preschool slots for disadvantaged four‐year‐olds. Differences across counties in the timing of the rollout and in the magnitude of the state financial investments per child provide the variation in programs needed to estimate their effects on schooling outcomes in third grade. We find robust positive effects of each program on third‐grade test scores in both reading and math. These effects can best be explained by a combination of direct benefits for participants and spillover benefits for others. Our preferred models suggest that the combined average effects on test scores of investments in both programs at 2009 funding levels are equivalent to two to four months of instruction in grade 3.  相似文献   
978.
In order to connect the appearance of macrophages and giant cells in pulmonary tissue with the time of asphyxia the authors analyzed 50 asphyxiated human lungs paying their attention on the number of alveolar and interstitial macrophages and giant cells. They compared histological specimens of 25 asphixiated humans lungs following a slow asphyxia (30 min or more) with 25 histological specimens of asphyxiated human lungs following a rapid asphyxia (10-15 min). Alveolar and interstitial macrophages and giant cells per section, were considered and numbered. Controls were done on histological examination of traumatized lungs. In the pulmonary alveoli following on acute asphyxia there were 27.7+/-4.4 macrophages per section. Subjects dead after a slow asphyxiation showed 68.2+/-7.1 alveolar macrophages per section (p<0.001). Interstitial macrophages were also frequently present. No differences are detectable in the number of polynuclear giant cells between rapidly and slowly asphyxiated human lungs. The number of alveolar and interstitial macrophages per section can be considered as a further histological evidence of a slow asphyxia and can differentiate a slow asphyxia from an acute one.  相似文献   
979.
On the market several systems exist for collecting spent ammunition data for forensic investigation. These databases store images of cartridge cases and the marks on them. Image matching is used to create hit lists that show which marks on a cartridge case are most similar to another cartridge case. The research in this paper is focused on the different methods of feature selection and pattern recognition that can be used for optimizing the results of image matching.The images are acquired by side light images for the breech face marks and by ring light for the firing pin impression. For these images a standard way of digitizing the images used. For the side light images and ring light images this means that the user has to position the cartridge case in the same position according to a protocol. The positioning is important for the sidelight, since the image that is obtained of a striation mark depends heavily on the angle of incidence of the light. In practice, it appears that the user positions the cartridge case with +/-10 degrees accuracy.We tested our algorithms using 49 cartridge cases of 19 different firearms, where the examiner determined that they were shot with the same firearm. For testing, these images were mixed with a database consisting of approximately 4900 images that were available from the Drugfire database of different calibers.In cases where the registration and the light conditions among those matching pairs was good, a simple computation of the standard deviation of the subtracted gray levels, delivered the best-matched images. For images that were rotated and shifted, we have implemented a "brute force" way of registration. The images are translated and rotated until the minimum of the standard deviation of the difference is found. This method did not result in all relevant matches in the top position. This is caused by the effect that shadows and highlights are compared in intensity. Since the angle of incidence of the light will give a different intensity profile, this method is not optimal.For this reason a preprocessing of the images was required. It appeared that the third scale of the "à trous" wavelet transform gives the best results in combination with brute force. Matching the contents of the images is less sensitive to the variation of the lighting.The problem with the brute force method is however that the time for calculation for 49 cartridge cases to compare between them, takes over 1 month of computing time on a Pentium II-computer with 333MHz. For this reason a faster approach is implemented: correlation in log polar coordinates. This gave similar results as the brute force calculation, however it was computed in 24h for a complete database with 4900 images.A fast pre-selection method based on signatures is carried out that is based on the Kanade Lucas Tomasi (KLT) equation. The positions of the points computed with this method are compared. In this way, 11 of the 49 images were in the top position in combination with the third scale of the à trous equation. It depends however on the light conditions and the prominence of the marks if correct matches are found in the top ranked position. All images were retrieved in the top 5% of the database. This method takes only a few minutes for the complete database if, and can be optimized for comparison in seconds if the location of points are stored in files.For further improvement, it is useful to have the refinement in which the user selects the areas that are relevant on the cartridge case for their marks. This is necessary if this cartridge case is damaged and other marks that are not from the firearm appear on it.  相似文献   
980.
The survival of the tiger (Panthera tigris) is seriously threatened by poaching to provide raw materials for Traditional Chinese Medicines (TCMs). Most highly prized are the tiger's bones, which are used in combination with other animal and plant derivatives in pills and plasters for the treatment of rheumatism and other ailments. Hundreds of patent remedies have been produced which claim to contain tiger bone, but proof of its presence is needed, if legislation prohibiting the trade in endangered species is to be enforced. A highly sensitive tiger-specific real-time PCR assay has been developed to address this problem. Using primers specific to the tiger mitochondrial cytochrome b gene, successful amplification has been reliably achieved from blood, hair and bone as well as from a range of TCMs spiked with 0.5% tiger bone. Although capable of detecting fewer than 10 substrate molecules, the seven varieties of TCM pills and plasters tested showed no detectable trace of tiger DNA before spiking. Furthermore, sequencing several "tiger bone" fragments seized from TCM shops has shown that they actually originated from cattle and pigs. The potential effects of traditional bone preparation methods, evidence that much lower concentrations are used than alleged on TCM packaging, and substitution of bones from other species all suggest a low likelihood of detecting tiger DNA in patent medicines. Despite this, the basic methods have been thoroughly proven and can be readily applied to derivatives from other CITES protected species providing a rapid and highly sensitive forensic test for species of origin. Potential applications to the monitoring of wild populations are demonstrated by the successful identification of shed hairs and faecal samples.  相似文献   
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