全文获取类型
收费全文 | 4706篇 |
免费 | 146篇 |
专业分类
各国政治 | 150篇 |
工人农民 | 213篇 |
世界政治 | 311篇 |
外交国际关系 | 177篇 |
法律 | 3134篇 |
中国政治 | 24篇 |
政治理论 | 820篇 |
综合类 | 23篇 |
出版年
2023年 | 37篇 |
2021年 | 26篇 |
2020年 | 57篇 |
2019年 | 76篇 |
2018年 | 103篇 |
2017年 | 97篇 |
2016年 | 115篇 |
2015年 | 68篇 |
2014年 | 89篇 |
2013年 | 411篇 |
2012年 | 114篇 |
2011年 | 135篇 |
2010年 | 94篇 |
2009年 | 120篇 |
2008年 | 117篇 |
2007年 | 116篇 |
2006年 | 122篇 |
2005年 | 82篇 |
2004年 | 102篇 |
2003年 | 108篇 |
2002年 | 85篇 |
2001年 | 208篇 |
2000年 | 207篇 |
1999年 | 149篇 |
1998年 | 61篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 52篇 |
1994年 | 59篇 |
1993年 | 52篇 |
1992年 | 118篇 |
1991年 | 106篇 |
1990年 | 132篇 |
1989年 | 121篇 |
1988年 | 136篇 |
1987年 | 129篇 |
1986年 | 100篇 |
1985年 | 106篇 |
1984年 | 80篇 |
1983年 | 71篇 |
1982年 | 52篇 |
1981年 | 47篇 |
1980年 | 40篇 |
1979年 | 50篇 |
1978年 | 36篇 |
1976年 | 30篇 |
1975年 | 28篇 |
1974年 | 39篇 |
1973年 | 28篇 |
1970年 | 27篇 |
排序方式: 共有4852条查询结果,搜索用时 15 毫秒
361.
Gruszecki AC Kloda S Simmons GT Daly TM Hardy RW Robinson CA 《Journal of forensic sciences》2003,48(2):432-434
A 29-year old female with a history of depression was found dead in a hotel room. The death scene investigation found empty pill bottles and an empty liter bottle of wine. Metaxalone, a centrally acting muscle relaxant, along with citalopram, ethanol, and chlorpheniramine were identified in the postmortem samples and quantitated by gas chromatography-mass spectrometry. The concentration of metaxalone in femoral vein blood was 39 mg/L. The heart blood concentration was 54 mg/L. Femoral vein blood concentrations of citalopram and chlorpheniramine were 0.77 mg/L and 0.04 mg/L, respectively. Ethanol levels were 0.13 g/dL in vitreous and 0.08 g/dL in heart blood. Other tissue samples were also analyzed. The authors consider the metaxalone concentrations toxic and potentially fatal. The citalopram concentrations were lower than those reported in fatal cases for this drug alone. Death was ascribed to polydrug abuse/overdose with metaxalone a major contributor. This represents the first reported case to our knowledge in which a metaxalone overdose significantly contributed to death. 相似文献
362.
This study was conducted in an attempt to develop a metallographic method for the investigation of pipe bombings. Three common pipe materials, ASTM A53 steel, AISI 304L stainless steel, and 6061-T6 aluminum, were shock-loaded using five high explosives and three propellants. The explosives used were ANFO, Composition C4, C6 detasheet, nitroglycerine-based dynamite, and flake TNT. The propellants used were FFFFg black powder. Red Dot smokeless powder, and Turbo Fuel A. The post-blast microstructure, hardness, and, in the case of 304L, transformed martensite content were examined for each test. The damage done to the microstructure was found to increase with increasing detonation velocity of the explosives and increase in pressure generated by the shock-metal interaction. Material hardness and, in the case of 304L, martensite content showed a sharp increase followed by a plateau as the shock pressure and detonation velocity increased. 相似文献
363.
Disability has high societal and personal costs. Various disparate federal and state programs attempt to address the economic and social needs of people with disabilities. Presumably workplace injuries and accidents are an important source of disability. Yet separate public policies and research literatures have evolved for these two social problems--disability and workplace injuries--despite their relatedness. This article seeks to document the overlap between these two phenomena in estimating the proportion of the disabled population whose disability was caused by workplace injury, accident, or illness using the Health and Retirement Study of 1992. The results point toward the need for initiatives to reduce disability that focus on work-related causes, which are a common pathway to disability, and that may result in substantial savings in federal programs. 相似文献
364.
365.
366.
Melton T Clifford S Kayser M Nasidze I Batzer M Stoneking M 《Journal of forensic sciences》2001,46(1):46-52
Variation in the mitochondrial DNA (mtDNA) control region as detected by sequence-specific oligonucleotide (SSO) probes is described for 2282 individuals from African-American, European-American, and Hispanic subpopulations from five broadly defined regions of North America (Northeast, Southeast, Central, Northwest, Southwest). Population diversity estimates were uniformly high for all subpopulations and for each major ethnic group. Only the Pennsylvania Hispanic group was remarkable with respect to its mitochondrial DNA types, having both six low frequency population specific types (ranging from 1.2-8.6%) and three high frequency shared types (10-20% each). There was no statistically significant subpopulation heterogeneity present within any of the three major groups at either the subpopulation level or the regional level (p > 0.01). However, statistically significant heterogeneity was measured when comparing the three major groups to each other, with the variance component attributable to this large division accounting for 18.60% of the total variance (p < 0.001). Overall mtDNA is a satisfactory forensic typing locus within broadly defined African-American, European-American, and Hispanic groups from North America, based on the high diversity estimates and absence of heterogeneity, as characterized by SSO typing. 相似文献
367.
368.
369.
Medical training in the United States often takes the form of a grueling endurance test in which patients are often those most at risk. This Article discusses sleep deprivation among resident physicians in the United States with an eye towards resolving the problem through legal channels. It analyzes the effects of sleep deprivation on resident physicians, with subsequent discussion of the implications for patient care and medical training. Next, it makes comparisons to medical training in other developed nations, as well as regulations that exist in the airline and trucking industries, where public safety is a principal concern. Furthermore, this Article discusses proposals to mend the dilemmas created by sleep-deprived resident physicians through statutory and regulatory reform, deterrence by way of tort law, and unionization or collective bargaining. 相似文献
370.
Carlin TM 《Journal of law and medicine》2001,9(1):95-104
A substantial proportion of the body of literature dealing with the question of whether or not a doctor stands in a fiduciary relationship with a patient in Australia assumes or asserts that this should be the case, despite strong indications to the contrary in Australian case law. Three key bases for making such assertions, the internationalist, revisionist and remedialist approaches, are identified and critiqued. It is argued that each of these approaches to justifying the characterisation of the doctor-patient relationship as a fiduciary one is flawed and unlikely to meet with success in future litigation. Additionally, there are issues of economic and resource allocation conflict in doctor-patient relationships. The implications for these conflicts in the doctor-patient fiduciary debate are briefly considered. It is concluded that, contrary to the dominant assertion in the extant literature on the subject, in Australia at least, the scales tip against, rather than towards, the characterisation of the doctor-patient relationship as a fiduciary one. 相似文献