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891.
The effects of carbon monoxide and cyanide on the hepatic redox state and energy charge were investigated. Rats were used for the experiment under pentobarbital anesthesia. Immediately after laparotomy, a rat was placed in an animal chamber made of a transparent plastic box and exposed to a test gas for 3 min. Every test gas was produced in a gas chamber connected to the animal chamber with a flexible tube. HCN was produced from NaCN and H2SO4. In the CO inhalation experiment, various amounts of CO were introduced into the gas chamber. Immediately after an exposure, about 2 g liver was frozen in situ with a precooled clamp. Oozed blood from the wound surface was sampled. Concentrations of ATP, ADP, AMP, acetoacetate, and beta-hydroxybutyrate in hepatic mitochondria were determined, and the redox state and the energy charge were calculated. For cyanide as well as CO, significant negative correlations were found between the concentration in the blood and the redox state. The same held true for the energy charge. The redox state showed a slight increase at low concentrations of both gases; however, thereafter it began to decrease sharply with increases in concentrations. When concentrations of the toxicant in the blood reached certain levels, a kind of turning point, beyond which the redox state does not decrease any more, was observed. It was about 40% for HbCO and about 2.0 micrograms/ml for cyanide, and the points seemed to be related to the concentrations, beyond which cells are irreversibly damaged. On the other hand, the energy charge did not change at low concentrations. With an increase in toxicant concentrations, the energy charge decreased drastically. The rate of decrease in the energy charge became higher when blood concentrations exceeded certain levels. It was about 40% for HbCO and 2.0 micrograms/ml for cyanide. The presence of low levels of blood cyanide did not affect the relationship between the energy charge and the HbCO concentration. 相似文献
892.
893.
Personal identification by radiographic comparison of vascular groove patterns of the calvarium 总被引:1,自引:0,他引:1
A case of forensic identification utilizing the vascular grooves within the skull is presented. The case is unique in that the antemortem radiographs were from childhood, rendering useless the more standard points of comparison. Calvarial vascular grooves represent unique points of comparison when the only available premortem radiographs were obtained during childhood, especially when one is attempting to identify children (living or dead). 相似文献
894.
The armamentarium of the forensic thanatologist includes the examiner's subjective assessment of bodily changes together with comprehensive evaluation of environmental and associated factors to estimate the postmortem interval (PMI). Of the various objective means, postmortem accumulation of potassium in vitreous humor is a widely used gauge. In view of the considerable variability inherent in these techniques, an additional marker with greater accuracy would be a welcome supplement to these indices. We have developed a method of estimating PMI from the level of 3-methoxytyramine (3-MT) in the dorsal putamen of the brain. The supernatant of a sample of putamen, sonicated in 6 volumes (weight/volume) of 0.1 M perchloric acid and centrifuged at 51 000 times gravity for 10 min, was analyzed for 3-MT using high-pressure liquid chromatography with electrochemical detection. The change of 3-MT in the putamen is linearly related to the PMI (range: 5.5 to 60 h), irrespective of patient age (1 to 84 years). This observation is attributable to several factors, including high substrate (dopamine) concentration, preservation of catechol-O-methyl transferase activity, and an inactivation of monoamine oxidase activity, as a result of a decrease in tissue pO2. 相似文献
895.
896.
The development strategy literature argues that autonomous bureaucrats in authoritarian Asian NICs followed successful export-led growth strategies while Latin American policymakers were pressured by mobilized sectors to maintain doomed import substitution industrialization. What is more, this ISI strategy made the consolidation of democracy impossible. However, my research on Venezuela indicates that ISI and democracy can be made compatible—the democratic state was penetrated by business and labor, those avenues for penetration were protected from electoral politics, and the relative participation of business and labor remained fluid. How are recently established democracies being made compatible with a new market-oriented development strategy? Evidence from East Asia and Latin America indicates that the transition to market-oriented economies and the institutionalization of participation by key sectors have not gone together. Policymakers are trying to isolate bureaucrats from public pressure and centralize power away from bodies vulnerable to electoral oversight. The “deinstitutionalization” of democratic politics may make the relationship between regime type and development strategy unstable. 相似文献
897.
Although the “stop snitching” phenomenon has brought recent attention to crime reporting, researchers have recognized for a long time the importance of this issue. Early studies focused on individual-level factors related to reporting, but recently, researchers have begun to examine neighborhood-level predictors. Most of these studies, however, omit key individual-level predictors of reporting and provide relatively little insight into the individual-level processes through which neighborhood context might affect reporting. This study uses survey data from a multisite, school-based study to examine whether neighborhood structural characteristics and individual-level attitudes and experiences are related to youths’ intentions to report crime. In addition, we assess whether neighborhood characteristics influence reporting via their effect on individual-level attitudes and experiences. We find that neighborhood poverty has an inverse relationship with crime reporting intentions and that numerous individual-level measures are associated with reporting, including attitudes toward the police, delinquency, and perceptions of the community. Importantly, the effects of neighborhood characteristics are reduced when youths’ attitudes and experiences are included in the model. Taken together, our findings suggest that neighborhood context might affect reporting by shaping the attitudes and experiences of youth. 相似文献
898.
899.
A simple and rapid method for the isolation of seven synthetic pyrethroid insecticides (methothrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin, fenvalerate, deltamethrin) with a solid phase extraction (SPE), utilizing Sep-Pak C18 cartridges, from human urine and plasma is presented. The detection of the insecticides was performed using a wide bore capillary gas chromatograph (GC) with flame ionization detection (FID). The insecticide-containing samples mixed with 70% methanol were directly applied to the cartridges and eluted with 2 ml chloroform. The recoveries using the cartridges were between 90-102% for urine and 81-93% for plasma. Mixing samples with 70% methanol prior to extraction, seems very useful for the screening of synthetic pyrethroid insecticides. 相似文献
900.