全文获取类型
收费全文 | 6924篇 |
免费 | 221篇 |
专业分类
各国政治 | 344篇 |
工人农民 | 279篇 |
世界政治 | 551篇 |
外交国际关系 | 243篇 |
法律 | 4098篇 |
中国政治 | 39篇 |
政治理论 | 1524篇 |
综合类 | 67篇 |
出版年
2020年 | 82篇 |
2019年 | 110篇 |
2018年 | 156篇 |
2017年 | 144篇 |
2016年 | 149篇 |
2015年 | 105篇 |
2014年 | 118篇 |
2013年 | 771篇 |
2012年 | 153篇 |
2011年 | 172篇 |
2010年 | 149篇 |
2009年 | 159篇 |
2008年 | 164篇 |
2007年 | 164篇 |
2006年 | 184篇 |
2005年 | 158篇 |
2004年 | 154篇 |
2003年 | 165篇 |
2002年 | 153篇 |
2001年 | 222篇 |
2000年 | 180篇 |
1999年 | 161篇 |
1998年 | 101篇 |
1997年 | 95篇 |
1996年 | 70篇 |
1995年 | 78篇 |
1994年 | 78篇 |
1993年 | 82篇 |
1992年 | 119篇 |
1991年 | 150篇 |
1990年 | 133篇 |
1989年 | 146篇 |
1988年 | 130篇 |
1987年 | 150篇 |
1986年 | 140篇 |
1985年 | 148篇 |
1984年 | 136篇 |
1983年 | 140篇 |
1982年 | 101篇 |
1981年 | 95篇 |
1980年 | 90篇 |
1979年 | 94篇 |
1978年 | 76篇 |
1977年 | 58篇 |
1976年 | 66篇 |
1975年 | 61篇 |
1974年 | 69篇 |
1973年 | 68篇 |
1972年 | 55篇 |
1969年 | 56篇 |
排序方式: 共有7145条查询结果,搜索用时 15 毫秒
961.
962.
A case is presented of a fatal drug interaction caused by ingestion of methocarbamol (Robaxin) and ethanol. Methocarbamol is a carbamate derivative used as a muscle relaxant with sedative effects. Therapeutic concentrations of methocarbamol are reported to be 24 to 41 micrograms/mL. Biological fluids were screened for ethanol using the Abbott TDx system and quantitated by gas-liquid chromatography (GLC). Determination of methocarbamol concentrations in biological tissue homogenates and fluids were obtained by colorimetric analysis of diazotized methocarbamol. Blood ethanol concentration was 135 mg/dL (0.135% w/v) and urine ethanol was 249 mg/dL (0.249% w/v). Methocarbamol concentrations were: blood, 257 micrograms/mL; bile, 927 micrograms/L; urine, 255 micrograms/L; gastric, 3.7 g; liver, 459 micrograms/g; and kidney, 83 micrograms/g. The combination of ethanol and carbamates is contraindicated since acute alcohol intoxication combined with carbamate usage can lead to combined central nervous system depression as a result of the interactive sedative-hypnotic properties of the compounds. 相似文献
963.
Genetic polymorphism of transferrin (TF) was revealed in human urine by isoelectric focusing and immunoblotting on thin-layer polyacrylamide gels. Using this technique more than 300 urine samples were examined, and correct TF typing from a small volume of urine (approx. 0.5 ml) was achieved, in comparison with the results of direct grouping for plasma. Three common phenotypes, TF C1, C2-1 and C2, were differentiated. In addition, the rare types TF C1D, C2D, and C1B were observed. The frequencies of the TF alleles in our samples were found to be: TF*C1 = 0.7265, TF*C2 = 0.2624, TF*D = 0.0083 and TF*B = 0.0028. 相似文献
964.
A series of calcium phosphate standards having calcium/phosphorus (Ca/P) molar ratios of 0.50, 1.00, 1.50, and 1.67, respectively, was prepared for bulk specimen analysis using scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDXA). The standards were mounted on carbon planchettes as either pure crystals or crystals embedded in epoxy resin. Ten different samples of each embedded and non-embedded standard were analyzed in a JEOL 100 CX electron microscope interfaced with a Kevex 8000 EDXA system using a lithium-drifted silicon detector and a multichannel analyzer. The Ca/P ratios were determined by calculating both net peak intensities without matrix corrections and atomic kappa-ratios using the MAGIC V computer program with ZAF correction factors for quantitative analysis. There was such extensive absorption of phosphorus X-rays in standards embedded in an epoxy matrix that the observed Ca/P ratios were statistically compatible with four different standards ranging in theoretical Ca/P ratios from 1.0 to 1.67. Although the non-embedded crystals showed a greater separation in the Ca/P ratios, both methods of preparation produced serious flaws in analysis. Direct application of the discovery of this caveat to the identification of suspected bone fragments for forensic science purposes is discussed. 相似文献
965.
966.
967.
W G Eckert 《The American journal of forensic medicine and pathology》1982,3(3):221-230
The physician, like any other human being, is subject to emotional problems, greed, jealousy, and instability of an individual under stress as well as mental disease which may all bring out improper behavior or criminal activity. Over the last two centuries, there have been instances where physicians have committed deliberate acts of murder on wives, relatives, patients, and others. Their motivation has ranged from ridding themselves of a nagging wife or for insurance and inheritance gains to insane acts. The methods used have usually been associated with poisons and drugs, of which the physician may have great familiarity. The frequency of physician-involved murders seems to have increased in the past two decades with several sensational cases being the topics of media coverage and further review in books and visual media, including television and the movies. The investigation of these cases may be very difficult, especially when a drug may be given to a victim which could cause severe problems after small amounts are given. The detection of death as being a murder may be the first problem faced, the demonstration of the fatal agent in the body in the next problem, and probably the most difficult is finding a suspect with the medication in his or her possession or paraphenalia for injecting such as a syringe and needle. The stealth and cunning of the murderer may further complicate the picture for the investigator as well as the reputation of the physician in the community, which is often above reproach so that the public has to be convinced of the actual involvement of the suspect. 相似文献
968.
969.
Upon investigation of semen- and blood-free vaginal swabs using starch gel electrophoresis the Phosphoglucomutase type was clearly identified in about 40%. Using cellulose acetate membrane electrophoresis PGM could not be demonstrated. In all cases the results correspond with those obtained in blood. No relation was found between secretor type (determined in saliva) and PGM typing. In vaginal material the following could not be determined: Adenylatkinase (AK) using starch gel electrophoresis, Esterase D (EsD) using cellulose acetate membrane electrophoresis, and Glyoxalase I (GLO) using agarose gel thin-layer electrophoresis. 相似文献
970.
An intrapleural free floating golf ball size body was an incidental finding at autopsy. The pathogenesis and clinical significance of this lesion are discussed. 相似文献