全文获取类型
收费全文 | 6762篇 |
免费 | 62篇 |
专业分类
各国政治 | 261篇 |
工人农民 | 296篇 |
世界政治 | 618篇 |
外交国际关系 | 281篇 |
法律 | 4027篇 |
中国政治 | 61篇 |
政治理论 | 1258篇 |
综合类 | 22篇 |
出版年
2021年 | 44篇 |
2020年 | 83篇 |
2019年 | 121篇 |
2018年 | 151篇 |
2017年 | 145篇 |
2016年 | 155篇 |
2015年 | 90篇 |
2014年 | 146篇 |
2013年 | 683篇 |
2012年 | 164篇 |
2011年 | 178篇 |
2010年 | 156篇 |
2009年 | 167篇 |
2008年 | 200篇 |
2007年 | 196篇 |
2006年 | 176篇 |
2005年 | 175篇 |
2004年 | 186篇 |
2003年 | 161篇 |
2002年 | 147篇 |
2001年 | 323篇 |
2000年 | 291篇 |
1999年 | 210篇 |
1998年 | 94篇 |
1997年 | 90篇 |
1996年 | 61篇 |
1995年 | 64篇 |
1994年 | 59篇 |
1993年 | 52篇 |
1992年 | 134篇 |
1991年 | 152篇 |
1990年 | 141篇 |
1989年 | 138篇 |
1988年 | 121篇 |
1987年 | 135篇 |
1986年 | 109篇 |
1985年 | 107篇 |
1984年 | 105篇 |
1983年 | 90篇 |
1982年 | 61篇 |
1981年 | 82篇 |
1980年 | 39篇 |
1979年 | 76篇 |
1978年 | 50篇 |
1975年 | 39篇 |
1974年 | 57篇 |
1973年 | 61篇 |
1972年 | 45篇 |
1971年 | 35篇 |
1970年 | 32篇 |
排序方式: 共有6824条查询结果,搜索用时 15 毫秒
91.
This article studies whether the attitudes of Norwegian doctors regarding surrogate decision power in end-of-life care conform to legal rules, particularly as they apply to the protection of children. The article is based on a hypothetical scenario concerning a critically ill child, believed to be dying, presented to 406 doctors. The study indicates that doctors may permit parental/surrogate decision-making to a greater extent than justified by law, sometimes in contravention of the child's best interests, which should be a fundamental guideline in all decisions that concern children. This article suggests a need to improve knowledge of doctors concerning parents'/surrogates' right to participate in life-or-death decisions. We conclude that Norway needs a precedent decision from the Supreme Court that confirms the right of judicial review of end-of-life decisions, and which applies the principle of the child's best interests as a fundamental guideline in the final decision. 相似文献
92.
The results of extraction of lambda-cigalotrin from dioxan aqueous solutions by hydrophobic organic solvents are presented. It is shown that the degree of extraction depends on the nature of the extractant, the water to dioxan ratio, and saturation of the water-dioxan layer with the electrolyte. The highest efficiency of lambda-cigalotrin extraction was achieved using chlorophorm as a solvent under desalination conditions. The extraction factor was calculated necessary to obtain the desired amount of lambda-cigalotrin from the water-dioxan solution (4:1) with the help of the extractants being used. 相似文献
93.
The present study explored the influence of survivor weight and participant gender, rape myth acceptance, and antifat attitudes on perceptions of sexual assault. Using an online survey tool, a community sample of 413 adult Canadian residents reviewed a hypothetical sexual assault scenario and completed a series of evaluations and attitudinal questionnaires. Generalized linear model analyses revealed that participants were more likely to hold the survivor responsible, excuse the perpetrator's actions, and respond more negatively toward the survivor and more positively toward the perpetrator when the survivor was depicted as thin versus overweight. Interactions were found between rape myth acceptance and survivor weight, gender and survivor weight, and gender and antifat attitudes, for certain dependent variables. In addition, men and those with higher levels of rape myth acceptance and antifat attitudes were found to make more negative evaluations of the survivor and more positive evaluations of the perpetrator. Recommendations for future research and interventions are discussed. 相似文献
94.
95.
The identification of human bodies in situations when there are no clues as to the person's identity from circumstantial data, poses a difficult problem to the investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 ((14)C) incorporated in the enamel of teeth from individuals from different geographical locations. The 'bomb pulse' refers to a significant increase in (14)C levels in the atmosphere caused by above ground test detonations of nuclear weapons during the cold war (1955-1963). By comparing (14)C levels in enamel with (14)C atmospheric levels systematically recorded over time, high precision birth dating of modern biological material is possible. Above ground nuclear bomb testing was largely restricted to a couple of locations in the northern hemisphere, producing differences in atmospheric (14)C levels at various geographical regions, particularly in the early phase. Therefore, we examined the precision of (14)C birth dating of enamel as a function of time of formation and geographical location. We also investigated the use of the stable isotope (13)C as an indicator of geographical origin of an individual. Dental enamel was isolated from 95 teeth extracted from 84 individuals to study the precision of the (14)C method along the bomb spike. For teeth formed before 1955 (N=17), all but one tooth showed negative Δ(14)C values. Analysis of enamel from teeth formed during the rising part of the bomb-spike (1955-1963, N=12) and after the peak (>1963, N=66) resulted in an average absolute date of birth estimation error of 1.9±1.4 and 1.3±1.0 years, respectively. Geographical location of an individual had no adverse effect on the precision of year of birth estimation using radiocarbon dating. In 46 teeth, measurement of (13)C was also performed. Scandinavian teeth showed a substantially greater depression in average δ(13)C (-14.8) than teeth from subjects raised in Japan (-13.5), Middle East and North Africa (-12.7) and South America (-10.9). In summary, isotopic analysis of carbon in enamel from a single tooth can give a good estimate of the year of birth of an individual and also provide information about the geographical origin of the individual. This strategy can assist police and forensic authorities when attempting to solve unidentified homicide cases and may facilitate the identification work associated with mass disasters. 相似文献
96.
Myiasis is defined as an infestation of the organs and/or tissues of human and other animals by fly maggots. Fly species that normally breed in meat or carrion (Diptera: Calliphoridae, Sarcophagidae) may become involved in cutaneous myiasis by colonizing preexisting wounds. Reports of human wound myiasis contracted in hospitals and nursing homes, especially when patients are chronically ill or bed-ridden, are not uncommon across North America and often result in cases of neglect and civil litigation. Based on a case history dealing with this latter situation and circumstances surrounding the treatment of maggot infestation, we designed an experiment to assess the effectiveness of wound cleansing solutions on maggot mortality. Treatments, consisting of four commonly used cleaning solutions (isopropyl alcohol, Dakin's solution, iodine, and hydrogen peroxide) and a control (deionized water), were applied to experimental units (n=5), with each unit consisting of groups of actively feeding Lucilia sericata maggots (Diptera: Calliphoridae). Every 24h, treatments were applied and mortality was assessed for the duration of the study (14 days). Total mean mortality increased over the duration of the experiment, with an initial large increase (10-25%) after the first treatment application, followed by a gradual increase over the remainder of the study. General differences among treatments indicated greatest mean total mortality for Dakin's solution (sodium hypochlorite) (46%), followed by isopropyl alcohol (42%), Betadine (37%), hydrogen peroxide (33%) and lowest mortality for the control (25%); however, no statistically significant differences were observed among treatments and no treatment resulted in 100% maggot mortality. Traditional wound cleansing solutions may not be sufficient for maggot infestations of pre-existing wounds and supplemental treatments may be necessary to effectively treat cases of wound myiasis. 相似文献
97.
98.
Recent headlines comparing the health risks of nanotechnology to those of asbestos have appeared in newspapers throughout the country and on the Internet. Governmental agencies and standard-setting organizations have begun considering and actually adopting requirements to protect against such purported risks. The plaintiffs’ bar and potential plaintiffs have surely taken note. There is every reason to believe that the era of mass tort and class actions related to nanotechnology—“nanotorts” for short—is rapidly approaching. This article examines what nanotort claims might look like, the role that regulations and industry practices may play in such lawsuits, potential defenses to those claims, and what nanotech companies can do now to guard against future nanotort liabilities. 相似文献
99.
Eun J. Lee Ph.D. In K. Hwang M.S. Nam Y. Kim M.D. Kyung L. Lee Ph.D. Myun S. Han Ph.D. Yang H. Lee Ph.D. Mu Y. Kim Ph.D. Moon S. Yang Ph.D. 《Journal of forensic sciences》2010,55(5):1202-1208
Abstract: The proper identification of illicit plants such as Papaver somniferum L (opium poppy) is important for law enforcement agencies. The identification of opium poppy was presently tested using 10 genetic markers that are universal for all plants or specific to a few poppy plants. The genetic distances of universal markers such as nuclear internal transcribed spacer (ITS), 18S rRNA, plastid rbcL, and trnL‐trnF intergenic spacer (IGS) of 14 species included in the Papaveraceae and Fumariaceae family were acquired by sequence comparisons. Both the ITS region and trnL‐trnF IGS showed high levels of interspecific divergence. Six Papaver genera‐specific markers were developed from coding regions involved in morphine biosynthesis. Three markers (TYDC, NCS, and BBE) produced amplicons only in opium poppy, providing a presence/absence test for opium poppy, while three additional markers (CYP80B1, SAT, and COR) were genus specific. These 10 markers might be useful for the forensic DNA analysis of opium poppy. 相似文献
100.
G K Murphy 《The American journal of forensic medicine and pathology》1991,12(2):98-101
Although gunshot is by far the most common means of homicide in the United States, significant numbers of homicides are also perpetrated by other means. Blunt-force injuries are produced by a variety of objects, including hands and feet and many different weapons. Some of these objects produce distinctive patterns of injury of potential evidentiary value. This paper presents a series of 20 consecutive blunt-force homicides in adults. Seventy percent (14 cases) of the victims were men. Thirty percent (six cases) followed an argument or altercation. A number of the weapons used were "weapons of opportunity" seized in the course of the incidents. Sixty-nine percent (nine cases) of known assailants were acquainted with their victims. Few characteristic patterned injuries were seen. Not surprisingly, craniocerebral trauma was the most common cause of death. One half (10 cases) the victims survived their assaults for varying periods of time. Homicides due to blunt-force injury still pose a significant challenge for the forensic pathologist, who must obtain a complete and accurate history of the fatal incident, interpret patterns of injury and other findings at autopsy, and correlate all of the findings to make an accurate ruling of the cause and manner of death. 相似文献