全文获取类型
收费全文 | 926篇 |
免费 | 53篇 |
专业分类
各国政治 | 58篇 |
工人农民 | 44篇 |
世界政治 | 58篇 |
外交国际关系 | 69篇 |
法律 | 387篇 |
中国政治 | 12篇 |
政治理论 | 339篇 |
综合类 | 12篇 |
出版年
2023年 | 9篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 31篇 |
2017年 | 36篇 |
2016年 | 50篇 |
2015年 | 26篇 |
2014年 | 39篇 |
2013年 | 128篇 |
2012年 | 36篇 |
2011年 | 35篇 |
2010年 | 28篇 |
2009年 | 28篇 |
2008年 | 22篇 |
2007年 | 26篇 |
2006年 | 41篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 38篇 |
2002年 | 34篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 14篇 |
1998年 | 16篇 |
1997年 | 19篇 |
1996年 | 4篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1983年 | 5篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 3篇 |
排序方式: 共有979条查询结果,搜索用时 15 毫秒
151.
Recently, a sample containing cyclopropylfentanyl was analyzed at this laboratory. Cyclopropylfentanyl began to appear in the United States' illicit drug markets in 2017. Unfortunately, cyclopropylfentanyl presents an analytical challenge due to its mass spectrum being almost identical to that of crotonylfentanyl. There are two possible isomers of crotonylfentanyl, Z- and E- crotonylfentanyl. In order to provide sufficient analytical data to distinguish the two isomers of crotonylfentanyl and cyclopropylfentanyl, crotonylfentanyl was synthesized and fully characterized. Each isomer was analyzed via nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry, and Fourier transform infrared spectroscopy. During the synthesis of crotonylfentanyl, an unknown compound was formed. The identification of this compound and the analytical characterization of the two isomers of crotonylfentanyl are presented. Through the comparison of these compounds, it was confirmed that cyclopropylfentanyl can be differentiated from crotonylfentanyl. 相似文献
152.
Patrick M. Seffrin 《Justice Quarterly》2017,34(4):652-673
Sexually active men, who are not in a monogamous relationship, may be at a greater risk for violence than men who are sexually active within monogamous relationships and men who are not sexually active. The current study examines changes in sexual behavior and violence in adolescence to early adulthood. Data on male (n = 4,597) and female (n = 5,523) respondents were drawn from four waves of the National Longitudinal Study of Adolescent and Adult Health (Add Health). HLM regression models indicate that men who transition to a monogamous, or less competitive, mode of sexual behavior (fewer partners since last wave), reduce their risk for violence. The same results were not replicated for females. Further, results were not accounted for by marital status or other more readily accepted explanations of violence. Findings suggest that competition for sex be further examined as a potential cause of male violence. 相似文献
153.
We describe an infant with an acute subdural hematoma, a fatal head injury, and severe hemorrhagic retinopathy caused by a stairway fall. His cerebral and ocular findings are considered diagnostic of abusive head trauma by many authors. Our literature search of serious injuries or fatalities from stairway or low-height falls involving young children yielded 19 articles of primary data. These articles are discrepant, making the classification of a young child's death following a reported short fall problematic. This case report contradicts the prevalent belief of many physicians dealing with suspected child abuse that low-height falls by young children are without exception benign occurrences and cannot cause fatal intracranial injuries and severe retinal hemorrhages. The irreparable harm to a caregiver facing an erroneous allegation of child abuse requires physicians to thoroughly investigate and correctly classify pediatric accidental head injuries. 相似文献
154.
Suicide by burning is an extreme act that is uncommon in the United States and throughout the Western world. The characteristics of people who complete such acts are not well understood. To address this issue, we examined the death records of the King County Medical Examiner's Office in Washington State over the 13 years from 1996 to 2009. Twenty-five cases of suicide by burning were identified and used to characterize decedent demographics, circumstances of death, and motivating factors. Compared to other methods of suicide, burning demonstrated a significant overrepresentation of decedents who were women, 40-59 years of age, and Asian/Pacific Islander. They also tended to have previous psychiatric illness and/or substance abuse issues. Self-burning predominantly occurred at the decedent's residence with the intent of suicide given. There was no unifying theme in motivating factors. Together, these data represent the characteristics of people whose death is because of suicide by burning in King County, Washington. 相似文献
155.
DeYoung PA Hall CC Mears PJ Padilla DJ Sampson R Peaslee GF 《Journal of forensic sciences》2011,56(2):366-371
A procedure has been developed to analyze the trace element concentrations in glass fragments using particle-induced X-ray emission (PIXE) spectrometry. This method involves using accelerated protons to excite inner-shell electronic transitions of target atoms and recording the resultant X-rays to characterize the trace element concentrations. The protocol was able to identify those glass fragments that originated from different sources based on their elemental analyses. The protocol includes specific approaches to calculating uncertainties and handling measurements below the level of detection. The results indicate that this approach has increased sensitivity for several elements with higher atomic number compared with X-ray fluorescence methods. While not as sensitive as laser-ablation or inductively coupled plasma mass spectrometry methods of dissolved samples, it is entirely nondestructive and entails a much simpler sample preparation process that may be used to presort glass fragments for more comprehensive elemental analysis. As such, the technique described may have a niche role in forensic glass analysis. 相似文献
156.
Star H Thevissen P Jacobs R Fieuws S Solheim T Willems G 《Journal of forensic sciences》2011,56(Z1):S77-S82
Abstract: Secondary dentine is responsible for a decrease in the volume of the dental pulp cavity with aging. The aim of this study is to evaluate a human dental age estimation method based on the ratio between the volume of the pulp and the volume of its corresponding tooth, calculated on clinically taken cone beam computed tomography (CBCT) images from monoradicular teeth. On the 3D images of 111 clinically obtained CBCT images (Scanora®3D dental cone beam unit) of 57 female and 54 male patients ranging in age between 10 and 65 years, the pulp–tooth volume ratio of 64 incisors, 32 canines, and 15 premolars was calculated with Simplant® Pro software. A linear regression model was fit with age as dependent variable and ratio as predictor, allowing for interactions of specific gender or tooth type. The obtained pulp–tooth volume ratios were the strongest related to age on incisors. 相似文献
157.
158.
Davis NL Horan PM Romich T Roman JL Lacy JM Catanese CA 《The American journal of forensic medicine and pathology》2010,31(4):330-334
This is a series reviewing 14 cases of giant saccular aneurysms diagnosed at the Office of the Chief Medical Examiner of New York City collected over an 11-year period. Data collected on all 14 cases included neuropathological findings, comorbidities, and toxicological findings. Of these 14 cases, 8 were in women, and the ages ranged from 3 to 79 years, with a mean and a median of 50 years. Women were overrepresented in the sixth through eighth decades. Of the 14 cases described, 11 presented with a subarachnoid hemorrhage; 3, no hemorrhage; 2, subdural hemorrhage; 8, intraventricular hemorrhage; 2, intracerebral hemorrhage; and 8, more than 1 hemorrhage type. Location of the aneurysms varied with 6 in the left side of the brain, 6 present in the right side of the brain, and 2 at the midline. We described the clinical, pathological, and toxicological findings associated with these giant aneurysms. 相似文献
159.
160.
Patrick T. McGonigal Samantha L. Bernecker Michael J. Constantino 《The journal of forensic psychiatry & psychology》2018,29(5):774-781
Despite the prevalence of anger management programs in correctional settings, there is mixed support for their effectiveness, and little is known about who benefits most. This preliminary study aimed to (1) evaluate the effectiveness of anger management for inmates, and (2) examine baseline psychopathology and midtreatment variables as response predictors. Participants were 30 incarcerated men undergoing 12-session anger management groups. Post-intervention, inmate-reported anger, and disciplinary actions decreased. Increased reported emotion regulation strategies predicted anger reduction. 相似文献