全文获取类型
收费全文 | 12666篇 |
免费 | 362篇 |
专业分类
各国政治 | 871篇 |
工人农民 | 449篇 |
世界政治 | 1042篇 |
外交国际关系 | 624篇 |
法律 | 6692篇 |
中国政治 | 72篇 |
政治理论 | 3155篇 |
综合类 | 123篇 |
出版年
2020年 | 145篇 |
2019年 | 185篇 |
2018年 | 243篇 |
2017年 | 284篇 |
2016年 | 307篇 |
2015年 | 215篇 |
2014年 | 279篇 |
2013年 | 1669篇 |
2012年 | 284篇 |
2011年 | 318篇 |
2010年 | 285篇 |
2009年 | 281篇 |
2008年 | 357篇 |
2007年 | 427篇 |
2006年 | 369篇 |
2005年 | 321篇 |
2004年 | 328篇 |
2003年 | 339篇 |
2002年 | 308篇 |
2001年 | 374篇 |
2000年 | 338篇 |
1999年 | 311篇 |
1998年 | 216篇 |
1997年 | 170篇 |
1996年 | 172篇 |
1995年 | 138篇 |
1994年 | 143篇 |
1993年 | 147篇 |
1992年 | 191篇 |
1991年 | 242篇 |
1990年 | 228篇 |
1989年 | 208篇 |
1988年 | 223篇 |
1987年 | 248篇 |
1986年 | 243篇 |
1985年 | 198篇 |
1984年 | 198篇 |
1983年 | 185篇 |
1982年 | 146篇 |
1981年 | 136篇 |
1980年 | 113篇 |
1979年 | 163篇 |
1978年 | 129篇 |
1977年 | 114篇 |
1976年 | 78篇 |
1975年 | 102篇 |
1974年 | 111篇 |
1973年 | 110篇 |
1972年 | 76篇 |
1971年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
821.
Häkkänen H 《Forensic science international》2005,152(1):61-64
In Finland, homicide by ligature strangulation is a rare event. The purpose of this study was to investigate recent homicide cases by ligature strangulation and to analyse offence and offender characteristics. All forensic psychiatric evaluation statements of offenders accused of ligature strangulation homicides during the 7-year period 1996--2002 (n=19) were reviewed retrospectively. Thirty-five percent of the victims were females. In four cases, the victim was the offender's intimate partner; in one case, it was the stepson; in one case, a father and in the rest of the cases (n=13), an acquaintance. None of the cases involved planning, sadism or sexual elements. In 89% of the cases, the offender was either intoxicated or on drugs at the time of the offence and in 94% of the cases, the victim was found at the scene of the killing. Of the offenders, 63% had crime history, and approximately half of the offenders had experienced parental alcohol abuse, domestic violence or previous trauma. Most of the offenders were unemployed at the time of the offence. In all, 89% were diagnosed as having personality disorder and two were schizophrenic. 相似文献
822.
Drummer OH 《Forensic science international》2005,150(2-3):133-142
This article reviews studies that have measured drug concentrations in oral fluid following controlled dosing regimens. A total of 23 studies have been identified over the last 15 years. These show that the amphetamines including designer amphetamines, cocaine, cannabis and cocaine are quickly found in oral fluid following dosing and usually have similar time-courses to that in plasma. Following common doses peak oral fluid concentrations exceed 0.1 microg/mL and often even 1 microg/mL. The drug concentration will depend on whether a dilution step occurs with buffer as part of the sampling procedure. The uses of collectors that stimulate oral fluid usually reduce the drug concentration compared to a non-stimulated manner. This reduction will not disadvantage the recipient since it will potentially reduce the detectability of drug in oral fluid compared to non-stimulated collections. Only one recent study has been reported for a benzodiazepine. This showed nanogram per milliliter concentrations for flunitrazepam. More studies are required for benzodiazepines and indeed for other drugs, particularly in multiple drug situations and where disease may affect the pharmacokinetics of drugs. 相似文献
823.
Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall "present"/"not found" reports calculated as true positives/(true positives+false negatives) were for the amphetamine specific assay 50%, methyl-amphetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques. 相似文献
824.
A controlled laboratory experiment was conducted in order to investigate the effect of the method of burial (i.e. the presence of coffin and clothing) on the formation of adipocere. This study follows previous studies by the authors who have investigated the effect of physical conditions on the formation of adipocere present in a controlled burial environment. The study utilises infrared spectroscopy to provide a preliminary lipid profile of the remains following a 12 month decomposition period. Inductively coupled plasma-mass spectrometry was employed as a technique for determining the salts of fatty acids present in adipocere. Gas chromatography-mass spectrometry (GC-MS) was used as the confirmatory test for the identification and determination of the chemical composition of adipocere which formed in the controlled burial environments. The results suggest that coffins will retard the rate at which adipocere forms but that clothing enhances its formation. The results concur with previous observations on adipocere formation in burial environments. 相似文献
825.
The medicolegal and subsequent criminologic interpretation of forensic and pathological findings in cases of homicide makes up an important tool of case profiling. In a retrospective study of 26 cases of "multiple homicides" involving 31 perpetrators (30 males, 1 female, mean age 33.5 years) and 73 victims (33 males, 40 females, mean age 36 years, 68 fatalities, 5 survivors), autopsy reports and prosecution authorities' files were investigated with regard to individual characteristics of victims and offenders, circumstances as well as mode of commitment. The major aim of this study was to comprehensively elucidate and characterise relevant forensic and criminologic features, which may gain importance for forensic case profiling. Forty-six victims were found in the close social environment of the perpetrator and 45 homicides were committed either in the victim's, the perpetrator's or the shared domicile. The main motives included concealment of a crime (n=13), personal conflicts/domestic arguments (n=7) and greed (n=12). The relevant injuries with regard to the cause of death were attributable to sharp force (n=13), blunt force (n=7), gunshot wounds (n=24), ligature strangulation (n=3), smothering (n=5), fire/carbon monoxide (n=4) and combined impacts (n=11). In 15 cases, so called defence injuries were found. In 5 victims a post-mortem blood alcohol concentration >1.5 g/l was determined. In six perpetrators, a severe psychiatric impairment of juridical responsibility was ascertained (Section 20 German criminal code, n=2, psychosis; Section 21 German criminal code, n=4, acute alcohol intoxication). As far as conviction data were available, 27 crimes were juridically assessed as murder, 12 as manslaughter and one as bodily harm with fatal consequences. 相似文献
826.
The solution parameters associated with gradient elution reversed phase high-performance liquid chromatography (HPLC) were characterized by evaluating the electrospray ionization mass spectrometry (ESIMS) response of selected smokeless powder additives. Using direct liquid infusion, the positive ion ESIMS responses were determined for three general classes of powder constituents: dialkylphthalate acid esters, N,N'-dialkyl-N,N'-diphenyl urea based stabilizers and nitroso-, nitro-, and dinitro- derivatives of diphenylamine. The relative ESIMS intensities of the powder components were investigated as a function of three solution parameters: ammonium acetate concentration, pH, and percent methanol. The effect of the ammonium acetate concentration demonstrates that the electrolyte is required for efficient ionization and the ESIMS intensity was optimal at a concentration of 2mM for the selected compounds, except 2,4'-dinitrodiphenylamine. The aqueous solution pH, corresponding to the available protons in solution, did not have a significant effect on the ESIMS intensity of the analytes. The percent methanol was evaluated with both decreasing and constant electrolyte concentrations to demonstrate the effects of droplet stability and ion transfer into the gas phase. These findings were applied to the analysis of the selected smokeless powder additives using HPLC-ESIMS to illustrate increased sensitivity for the protonated molecules. 相似文献
827.
828.
829.
830.