全文获取类型
收费全文 | 2150篇 |
免费 | 83篇 |
专业分类
各国政治 | 170篇 |
工人农民 | 111篇 |
世界政治 | 107篇 |
外交国际关系 | 82篇 |
法律 | 1421篇 |
中国政治 | 17篇 |
政治理论 | 309篇 |
综合类 | 16篇 |
出版年
2023年 | 15篇 |
2022年 | 16篇 |
2021年 | 15篇 |
2020年 | 47篇 |
2019年 | 52篇 |
2018年 | 62篇 |
2017年 | 93篇 |
2016年 | 85篇 |
2015年 | 48篇 |
2014年 | 50篇 |
2013年 | 268篇 |
2012年 | 66篇 |
2011年 | 77篇 |
2010年 | 53篇 |
2009年 | 57篇 |
2008年 | 65篇 |
2007年 | 60篇 |
2006年 | 59篇 |
2005年 | 65篇 |
2004年 | 62篇 |
2003年 | 66篇 |
2002年 | 50篇 |
2001年 | 68篇 |
2000年 | 50篇 |
1999年 | 49篇 |
1998年 | 18篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 14篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 30篇 |
1991年 | 32篇 |
1990年 | 36篇 |
1989年 | 40篇 |
1988年 | 36篇 |
1987年 | 26篇 |
1986年 | 35篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 16篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1979年 | 19篇 |
1978年 | 21篇 |
1977年 | 16篇 |
1971年 | 18篇 |
1970年 | 17篇 |
1968年 | 17篇 |
1967年 | 12篇 |
排序方式: 共有2233条查询结果,搜索用时 15 毫秒
111.
The forensic pathologist increasingly relies on the forensic anthropologist to be the consulting expert in human identification. Likewise, if identification is not possible from visual inspection of skeletal remains, the forensic biologist may be called upon to conduct DNA analysis. The possibility of downstream DNA testing needs to be considered when skeletal preparation techniques are employed to deflesh human remains, as they have the potential to strongly impact genetic analyses and subsequent identification. In this study, three cleaning techniques, boiling bone in water, in bleach, and in powdered detergent/sodium carbonate, were tested for their effect on nuclear and mtDNA recovery from a variety of human and non-human bones. A statistically significant reduction in DNA yields occurred in non-human bones cleaned with bleach, and DNA degradation was apparent electrophoretically. The human bones also showed much lower yields from bleach cleaning, while the detergent/carbonate method allowed the largest segments of DNA to be amplified, indicating it may have a less degradative effect on bone DNA than either of the other cleaning processes. 相似文献
112.
The technique is proposed allowing quantitation of brain edema and typing of liquor distribution in different parts of brain tissue. In combination with other assays this test can determine a variant of tanatogenesis, detect cause of death and duration of the terminal period. The method application is illustrated by the study of brain hydration in mechanical strangulation asphyxia. It is shown that this death is associated with hypohydration of cerebral structures, especially pronounced in the cortical compartments. 相似文献
113.
Some causes of ineffective dental care because of the patient's negligence were analyzed. In 16 cases the patients ignored recommendations of the dentist and missed visits to the doctor. As a result, the patients developed complications leading to esthetic dissatisfaction, prolonged treatment, repeated prosthetic management. 相似文献
114.
Zviagin VN Mal'tseva NL Aleksina LA Galitskaia OI 《Sudebno-meditsinskaia ekspertiza》2005,48(6):27-34
We studied 16 sizes of the hyoid bone (HB) from 158 corpses of known gender, Russians, who had died at the age over 15 years by the K. Miller et al program (1998) and 205 back projection electroroentgenograms of the neck of patients of the traumatological hospital in the town of Kirov. HB skeletization was made by the enzymatic drug enzyme. SPSS package and multidimentional statistics (regression and discriminant analyses) were used for data processing. It was established that HB is an informative object of forensic medical personal identification allowing determination of the body length and gender as well as anatomical, x-ray and osteometric individual features. Precision of human body length diagnosis by HB is 6.71-7.26 cm. Therefore, this method should be used in combination with the diagnosis by long tubular bones. Diagnosis of human gender by osteometric signs of HB based on one-dimentional discriminant analysis is feasible in 80-85%, based on canonical discriminant analysis--in 91.1% cases. The method of anatomic, osteometric and roentgenological assessment of HB individuality can be used in personal identification by intravital x-ray of cervical organs and in traumatic defects of HB. The methods may be applied in forensic medical practice in expert examination of body fragments or isolated bone fragments. 相似文献
115.
An investigation of the following psychoactive drugs: barbiturate, benzodiazepine, meprobamate, methaqualone and phenothiazine, was performed on all automobile occupants killed in accidents in southern Sweden during 1977 and 1978. Of 122 drivers and 55 passengers analysed, low concentrations of these drugs were found in nine drivers and in five passengers. Thus, 7.3% of the drivers were driving under the influence of drugs and, of these, two drivers (1.6% of all analysed drivers) were also inebriated. Twenty-three per cent of the drivers were inebriated only. According to the circumstances in the accidents and the number of drivers whose analyses proved positive, drug influence seldom seems to be the cause of fatal traffic accidents. 相似文献
116.
117.
118.
Two factors potentially affect observers'attributions of responsibility to a rape survivor: how closely they identify with the survivor and how much they adhere to rape myths. To assess the impact of these factors, 157 female college students categorized by their sexual assault history and by their acceptance of rape myths, evaluated a sexual assault scenario. It was hypothesized that previously victimized participants would attribute less blame, and that those participants who self-identify as rape survivors would view the assault as rape more often than other participants. Neither hypothesis was supported. As expected, those who scored higher on the Rape Myths Acceptance Scale(RMAS) blamed the victim more and were less likely to believe rape had occurred. Only one subscale of the RMAS, Adversarial Sexual Beliefs, was consistently associated with participants'evaluation of the scenario, suggesting that this dimension may be especially important to understanding an observer's assessment of rape. 相似文献
119.
Reliable, sensitive, rapid and quantitative enzyme-based assay for gamma-hydroxybutyric acid (GHB) 总被引:1,自引:0,他引:1
Several assays for gamma-hydroxybutyrate (4-hydroxybutyrate, GHB) have been developed based on the enzyme gamma-hydroxybutyrate dehydrogenase (GHB-DH). Enzymatic oxidation of GHB by NAD+ is coupled to diaphorase-mediated reduction of pro-dye to yield colored product. GHB-DH from Ralstonia eutropha was cloned and expressed as a stable fusion protein easily purified by affinity chromatography. Quantitative initial velocity and endpoint versions of the assay in solution are described. Michaelis-Menten parameters for oxidation of GHB and ethanol were estimated. A semi-quantitative "dipstick" version of the assay on paper also is described. Both solution endpoint and "dipstick" assays are sensitive to about 0.05 mg GHB/mL using 10 microL of sample. Ethanol at concentrations possible in urine and agents used to stabilize physiological fluids for forensics analysis do not interfere significantly. The "dipstick" assay also allows detection of GHB in alcoholic beverages after evaporation of about one-fourth drop of beverage before testing. The enzymatic assay for GHB is reliable, sensitive, inexpensive and rapid. 相似文献
120.
A controlled laboratory experiment is described, in principle and practice, which can be used for the of determination the rate of tissue decomposition in soil. By way of example, an experiment was conducted to determine the effect of temperature (12 degrees, 22 degrees C) on the aerobic decomposition of skeletal muscle tissue (Organic Texel x Suffolk lamb (Ovis aries)) in a sandy loam soil. Measurements of decomposition processes included muscle tissue mass loss, microbial CO2 respiration, and muscle tissue carbon (C) and nitrogen (N). Muscle tissue mass loss at 22 degrees C always was greater than at 12 degrees C (p < 0.001). Microbial respiration was greater in samples incubated at 22 degrees C for the initial 21 days of burial (p < 0.01). All buried muscle tissue samples demonstrated changes in C and N content at the end of the experiment. A significant correlation (p < 0.001) was demonstrated between the loss of muscle tissue-derived C (Ct) and microbially-respired C (Cm) demonstrating CO2 respiration may be used to predict mass loss and hence biodegradation. In this experiment Q10 (12 degrees C-22 degrees C) = 2.0. This method is recommended as a useful tool in determing the effect of environmental variables on the rate of decomposition of various tissues and associated materials. 相似文献