全文获取类型
收费全文 | 20659篇 |
免费 | 594篇 |
专业分类
各国政治 | 919篇 |
工人农民 | 751篇 |
世界政治 | 1817篇 |
外交国际关系 | 791篇 |
法律 | 11736篇 |
中国共产党 | 2篇 |
中国政治 | 92篇 |
政治理论 | 4938篇 |
综合类 | 207篇 |
出版年
2021年 | 105篇 |
2020年 | 247篇 |
2019年 | 299篇 |
2018年 | 412篇 |
2017年 | 479篇 |
2016年 | 537篇 |
2015年 | 365篇 |
2014年 | 390篇 |
2013年 | 2228篇 |
2012年 | 497篇 |
2011年 | 507篇 |
2010年 | 432篇 |
2009年 | 490篇 |
2008年 | 542篇 |
2007年 | 574篇 |
2006年 | 550篇 |
2005年 | 498篇 |
2004年 | 495篇 |
2003年 | 514篇 |
2002年 | 469篇 |
2001年 | 741篇 |
2000年 | 688篇 |
1999年 | 565篇 |
1998年 | 372篇 |
1997年 | 306篇 |
1996年 | 234篇 |
1995年 | 269篇 |
1994年 | 297篇 |
1993年 | 273篇 |
1992年 | 397篇 |
1991年 | 410篇 |
1990年 | 372篇 |
1989年 | 399篇 |
1988年 | 371篇 |
1987年 | 392篇 |
1986年 | 389篇 |
1985年 | 393篇 |
1984年 | 342篇 |
1983年 | 358篇 |
1982年 | 303篇 |
1981年 | 284篇 |
1980年 | 211篇 |
1979年 | 283篇 |
1978年 | 197篇 |
1977年 | 175篇 |
1976年 | 154篇 |
1975年 | 140篇 |
1974年 | 153篇 |
1973年 | 136篇 |
1972年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
921.
922.
Robert Reagan 《环境索赔杂志》2019,31(3):191-217
AbstractFor nearly a decade, Republicans accused Democrats and the Obama Administration of waging a “war on coal” and Democrats has cited economics as the primary cause of the industry’s troubles. Now that President Trump has declared the war on coal to be over, it is time to examine the regulations promulgated during the Obama Administration and their impact on the industry. This article will discuss the coal industry prior to, during, and after the Obama Administration with particular attention to Obama-era regulations that impacted the industry and President Trump’s efforts to repeal and replace the same. 相似文献
923.
Chloë J. Wallace 《The Law teacher》2018,52(3):260-271
Learning legal reasoning is a central part of any undergraduate law degree and remains a threshold concept: one which is vital for any law student to grasp, but which is often difficult to explain. It is a form of reasoning which is very distinctive to the discipline. This article explores the applicability of learning theories typically used to ground pedagogy in higher education to the specific task of teaching legal reasoning. Constructivist or experiential theories of learning are widely used in higher education, but they need to be used with a clear focus on the specific nature of legal reasoning, which does not fit neatly within the assumptions about learning which underpin many constructivist approaches. Situated learning theories, which place emphasis on the role of the community in constructing knowledge, can also be of value. However, steps need to be taken to avoid replicating the hierarchy of the legal community within educational communities. Overall, the pedagogy of legal reasoning needs to pay attention to the specific nature of legal reasoning, to enable students to access the discourse of the legal community to use as a model, and to take students seriously as members of that community. 相似文献
924.
An often implicit assumption of perceptual deterrence tests is that the elicited values pertaining to arrest risk reflect stable underlying beliefs. But researchers in other disciplines have found that reported expectations are highly susceptible to exogenous factors (e.g., anchors and question ordering), indicating that such values are somewhat arbitrary responses to probabilistic questions. At the same time, reported expectations are coherent within persons, such that respondents rank order them rationally. For deterrence, then, absolute values reported on arrest risks are likely not stable but individuals still rank order specific crimes in meaningful ways. We examine the interpretability of reported arrest risk for three possibilities: 1) Reported risks are stable probabilistic values; 2) reported risks are arbitrary and uninformative for deterrence research; or 3) reported risks display “coherent arbitrariness” with unstable values between individuals but stable rank ordering of crimes within individuals. Through the use of three random experiments of college students, our results indicate that elicited risk perceptions are arbitrary in that they are influenced by the presentation of anchors and question ordering. Nevertheless, the rank ordering of crimes within and across conditions is unaffected by the presentation of anchors, suggesting that reported risks are locally coherent within persons. 相似文献
925.
Christopher J. Katilie BS Lauryn E. DeGreeff PhD Caitlin E. Sharpes MS Eric M. Best PhD Patricia E. Buckley PhD Jenna D. Gadberry BS Michele N. Maughan PhD 《Journal of forensic sciences》2023,68(6):2021-2036
While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel–oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material. 相似文献
926.
927.
Effects of positional restraint on oxygen saturation and heart rate following exercise 总被引:1,自引:0,他引:1
D T Reay J D Howard C L Fligner R J Ward 《The American journal of forensic medicine and pathology》1988,9(1):16-18
This report assesses the effects on peripheral oxygen saturation and heart rate that positional restraint induces when a person is prone, handcuffed, and "hog-tied." Peripheral oxygen saturation and heart rate were monitored at rest, during exercise, and during recovery from exercise for 10 adult subjects. The effects of positional restraint produced a mean recovery time that was significantly prolonged. Consequently, the physiological effects produced by positional restraint should be recognized in deaths where such measures are used. 相似文献
928.
Jamie K. Pringle Ph.D. John P. Cassella Ph.D. John R. Jervis Ph.D. Anna Williams Ph.D. Peter Cross M.Sc. Nigel J. Cassidy Ph.D. 《Journal of forensic sciences》2015,60(4):1052-1060
In homicide investigations, it is critically important that postmortem interval and postburial interval (PBI) of buried victims are determined accurately. However, clandestine graves can be difficult to locate; and the detection rates for a variety of search methods (ranging from simple ground probing through to remote imaging and near‐surface geophysics) can be very low. In this study, simulated graves of homicide victims were emplaced in three sites with contrasting soil types, bedrock, and depositional environments. The long‐term monthly in situ monitoring of grave soil water revealed rapid increases in conductivity up to 2 years after burial, with the longest study evidencing declining values to background levels after 4.25 years. Results were corrected for site temperatures and rainfall to produce generic models of fluid conductivity as a function of time. The research suggests soilwater conductivity can give reliable PBI estimates for clandestine burials and therefore be used as a grave detection method. 相似文献
929.
930.
A simultaneous equations model is estimated to analyze the interaction between state Medicaid pharmaceutical drug reimbursement rates, drug recipients per capita, and expenditures per drug recipient. Interest groups are shown to have a strong positive impact on pharmacy reimbursement rates, which, in turn, have an impact on pharmacy participation rates and drug utilization and expenditure patterns. Finally, a strong inverse relationship exists between expenditures per recipient and program size. The results verify the existence of substantial variation in state Medicaid programs and point to potentially growing disparities as a result of current policies. 相似文献