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991.
A biomechanical study of the human vertebral artery with implications for fatal arterial injury 总被引:8,自引:0,他引:8
We studied the biomechanical behaviour of ring and strip specimens from along the length of 18 vertebral arteries taken from 16 subjects aged 28-90 years, in order to consider some of the factors which may play a role in vertebral artery rupture. The method was chosen to allow a comparison between circumferential distension (ring samples) and longitudinal extension, (strip samples). The samples were extended between the jaws of a tensile testing apparatus until the specimen broke and a number of biomechanical parameters were derived. These were the percentage extension to break, the tensile strength, Young's modulus and the peak load. There were a number of important findings. The vertebral artery was shown to be susceptible to longitudinal stretching with a number of strip samples breaking when extended by as little as 16-20%. The tensile strength and load at peak of the strip specimens were correspondingly lower than for the ring samples. Marked intersubject variations were shown for all these parameters and prominent changes in behaviour occurred along the vertebral artery. This study indicates that the artery may be susceptible to head and neck movements which cause the vessel to stretch, and intersubject variations in behaviour may be one important explanation for the marked differences in outcome which appear to exist in subjects who suffer broadly similar head and neck insults. 相似文献
992.
Comparison techniques used in bite mark analysis are many and varied, the choice of technique depending largely on personal preference. Until recently, no one technique has been shown to be better than the others, and very little research has been carried out to compare different methods. This study evaluates and compares the accuracy of direct comparisons between suspects' models and bite marks with indirect comparisons in the form of conventional traced overlays of suspects' models or a new method using photocopier-generated overlays. Artificial bite marks in pigskin were made using standardized sets of models and recorded as photographs and fingerprint powder lifts on tape. The bite mark photographs and fingerprint lifts were coded and randomized so that a blind comparison could be made with the models, traced overlays, and photocopier-generated overlays using a modified version of the American Board of Forensic Odontology Scoring (ABFO) System for Bite Marks. It was found that the photocopier-generated overlays were significantly more accurate at matching the correct bite mark to the correct models irrespective of whether the bite mark was recorded photographically or as a fingerprint lift. The photocopier-generated overlays were also found to be more sensitive at matching the correct bite marks to the correct models than the other two methods used. The modified ABFO scoring system was able to discriminate between a correct match and several incorrect matches by awarding a high score to the correct match. 相似文献
993.
Erwin J. A. T. Mattijssen MSc Cilia L. M. Witteman PhD Charles E. H. Berger PhD Xiaoyu A. Zheng MSc Johannes A. Soons PhD Reinoud D. Stoel PhD 《Journal of forensic sciences》2021,66(1):96-111
Forensic firearm examination provides the court of law with information about the source of fired cartridge cases. We assessed the validity of source decisions of a computer‐based method and of 73 firearm examiners who compared breechface and firing pin impressions of 48 comparison sets. We also compared the computer‐based method's comparison scores with the examiners' degree‐of‐support judgments and assessed the validity of the latter. The true‐positive rate (sensitivity) and true‐negative rate (specificity) of the computer‐based method (for the comparison of both the breechface and firing pin impressions) were 94.4% and at least 91.7%, respectively. For the examiners, the true‐positive rate was at least 95.3% and the true‐negative rate was at least 86.2%. The validity of the source decisions improved when the evaluations of breechface and firing pin impressions were combined and for the examiners also when the perceived difficulty of the comparison decreased. The examiners were reluctant to provide source decisions for "difficult" comparisons even though their source decisions were mostly correct. The correlation between the computer‐based method's comparison scores and the examiners' degree‐of‐support judgments was low for the same‐source comparisons to negligible for the different‐source comparisons. Combining the outcomes of computer‐based methods with the judgments of examiners could increase the validity of firearm examinations. The examiners' numerical degree‐of‐support judgments for their source decisions were not well‐calibrated and showed clear signs of overconfidence. We suggest studying the merits of performance feedback to calibrate these judgments. 相似文献
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T H Ingalls 《The American journal of forensic medicine and pathology》1989,10(3):213-215
Epidemiologic evidence indicates that the outbreak of 30-40 cases of multiple sclerosis and other demyelinating syndromes in Galion, Ohio, USA, during 1982-1985 was related to an excess concentration of heavy-metal wastes, especially of cadmium and chromium in sewage and river water. Both multiple sclerosis and myasthenia gravis were diagnosed by board-certified neurologists. 相似文献
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An enzyme-linked immunosorbent assay for plasma-paraquat levels of poisoned patients 总被引:1,自引:0,他引:1
To investigate the efficacy of medical treatments, plasma-paraquat levels were measured in patients who had ingested the liquid weedkiller, Gramoxon, containing paraquat. We determined the levels by an enzyme-linked immunosorbent assay (ELISA) using a murine paraquat-specific monoclonal antibody developed by Niewola et al. (Clin. Chim. Acta, 148 (1985) 149-156). Using this ELISA, concentrations of paraquat in the range 1.56-100 ng/ml could be measured. This assay method had good precision and was suitable for measurement of low levels of paraquat. The therapeutic treatments were most effective on the day of admission. The plasma-paraquat levels of poisoned patients decreased significantly. However, the levels tended to increase again during the pause period of the haemoperfusion and this increase was serious for fatal cases. It is clear that elimination of poison not only from blood but also from tissues is necessary to lower the mortality rate. 相似文献