全文获取类型
收费全文 | 1340篇 |
免费 | 80篇 |
专业分类
各国政治 | 62篇 |
工人农民 | 55篇 |
世界政治 | 125篇 |
外交国际关系 | 143篇 |
法律 | 643篇 |
中国政治 | 8篇 |
政治理论 | 375篇 |
综合类 | 9篇 |
出版年
2023年 | 11篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 36篇 |
2019年 | 41篇 |
2018年 | 44篇 |
2017年 | 66篇 |
2016年 | 69篇 |
2015年 | 42篇 |
2014年 | 46篇 |
2013年 | 175篇 |
2012年 | 43篇 |
2011年 | 59篇 |
2010年 | 45篇 |
2009年 | 41篇 |
2008年 | 50篇 |
2007年 | 42篇 |
2006年 | 44篇 |
2005年 | 46篇 |
2004年 | 54篇 |
2003年 | 52篇 |
2002年 | 42篇 |
2001年 | 35篇 |
2000年 | 41篇 |
1999年 | 25篇 |
1998年 | 19篇 |
1997年 | 17篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 17篇 |
1992年 | 10篇 |
1991年 | 18篇 |
1990年 | 18篇 |
1989年 | 17篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 4篇 |
1985年 | 16篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有1420条查询结果,搜索用时 15 毫秒
181.
182.
183.
184.
The English Patents Court has recently refused a declarationof non-infringement in relation to the compound patent coveringAtorvastatin (Lipitor), the world's best-selling drug, but founda patent relating to its hemicalcium salt invalid for lack ofnovelty and obviousness; this decision is seen as a victoryfor Pfizer since the invalidation of the hemicalcium salt patenthas not shortened its period of exclusivity. 相似文献
185.
The application of infrared chemical imaging to the analysis of bicomponent fibers was evaluated. Eleven nominally bicomponent fibers were examined either side-on or in cross-section. In six of the 11 samples, infrared chemical imaging was able to spatially resolve two spectroscopically distinct regions when the fibers were examined side-on. As well as yielding characteristic infrared spectra of each component, the technique also provided images that clearly illustrated the side-by-side configuration of these components in the fiber. In one case it was possible to prepare and image a cross-section of the fiber, but in general the preparation of fiber cross-sections proved very difficult. In five of the 11 samples, the infrared spectra could be used to identify the overall chemical composition of the fibers, according to a published classification scheme, but the fiber components could not be spatially resolved. Difficulties that are inherent to conventional "single-point" infrared spectroscopy, such as interference fringing and sloping baselines, particularly when analyzing acrylic type fibers, were also encountered in the infrared chemical image analysis of bicomponent fibers. A number of infrared sampling techniques were investigated to overcome these problems, and recommendations for the best sampling technique are given. Chemical imaging results were compared with those obtained using conventional fiber microscopy techniques. 相似文献
186.
Eckenrode BA Ramsey SA Stockham RA Van Berkel GJ Asano KG Wolf DA 《Journal of forensic sciences》2006,51(4):780-789
The Scent Transfer Unit (STU-100) is a portable vacuum that uses airflow through a sterile gauze pad to capture a volatiles profile over evidentiary items for subsequent canine presentation to assist law enforcement personnel. This device was evaluated to determine its ability to trap and release organic compounds at ambient temperature under controlled laboratory conditions. Gas chromatography-mass spectrometry (GC-MS) analyses using a five-component volatiles mixture in methanol injected directly into a capture pad indicated that compound release could be detected initially and 3 days after the time of collection. Additionally, 15 compounds of a 39-component toxic organic gaseous mixture (10-1000 parts per billion by volume [p.p.b.(v)]) were trapped, released, and detected in the headspace of a volatiles capture pad after being exposed to this mixture using the STU-100 with analysis via GC-MS. Component release efficiencies at ambient temperature varied with the analyte; however, typical values of c. 10% were obtained. Desorption at elevated temperatures of reported human odor/scent chemicals and colognes trapped by the STU-100 pads was measured and indicated that the STU-100 has a significant trapping efficiency at ambient temperature. Multivariate statistical analysis of subsequent mass spectral patterns was also performed. 相似文献
187.
Pasquale-Styles MA Sochaski MA Dorman DC Krell WS Shah AK Schmidt CJ 《Journal of forensic sciences》2006,51(5):1154-1157
Bromethalin is a neurotoxin found in some rodenticides. A delusional 21-year-old male presented to a hospital with altered mental status the day after ingesting a bromethalin-based rodenticide. He died 7 days after his self-reported exposure to c. 17 mg bromethalin (equivalent to 0.33 mg bromethalin/kg). His clinicopathologic course was characterized by altered mental status, obtundation, increased cerebrospinal fluid pressure, cerebral edema, death, and diffuse histologic vacuolization of the white matter in the central nervous system seen on microscopic examination at autopsy. The presence of a demethylated form of bromethalin in the patient's liver and brain was confirmed by gas chromatography with mass spectrometry. Clinical signs and lesions observed in this patient are similar to those seen in animals poisoned with bromethalin. This case illustrates the potential for bromethalin ingestion to result in fatal human poisoning. 相似文献
188.
Schmidt LA Wiley J Dohan D Zabkiewicz D Jacobs LM Henderson S Zivot M 《Journal of health politics, policy and law》2006,31(5):945-980
Sharp declines in welfare rolls since the passage of welfare reform legislation have led many to label it a social policy success. Using data from prereform and postreform samples of welfare applicants and recipients, as well as ethnographic data on welfare reform implementation, we examine three hypotheses based on concerns raised during the welfare reform debate about the possible effects of new policies on substance abusers and addicts: First, they would be "scared off," or discouraged from applying to aid by welfare's new requirements surrounding work and treatment. Second, they might be "weeded out," or face discrimination in the application process because of concerns about the difficulty of moving them successfully from welfare to work. Third, they might be "bumped down," or shifted to local aid programs rather than moving from welfare to self-sufficiency. Our empirical analysis finds no evidence of scaring off or weeding out, and some evidence of bumping down. Using ethnographic data, we offer some possible explanations for these findings by placing them in the context of policy change and implementation in the years following welfare reform. 相似文献
189.
Padosch SA Dettmeyer RB Schmidt PH Musshoff F Madea B 《Forensic science international》2006,159(2-3):230-234
Spinal epidural haematomas (sEDH) can be regarded as rare events, in principle a spontaneous and a traumatic aetiology can be distinguished. Spontaneous spinal epidural haematomas can arise, e.g. from vascular malformations, coagulopathies, etc. On the other hand, traumatic sEDH are related to, e.g. spinal trauma or intraoperative vascular injuries. With regard to clinical significance, spinal epidural haematomas accompanied by transient mild neurological symptoms up to lethal outcomes have been observed. We report on a 53-year-old male alcoholic who was found in the kitchen of his asylum in a grotesquely fixed body position, with his head and cervical spine in a maximum anteflected position. A general practitioner had ruled for a non-natural manner of death due to "broken neck" and alcohol intoxication, therefore, the prosecution authorities called for a medicolegal autopsy. At autopsy, paravertebral soft tissue haemorrhage in between the shoulder blades was disclosed. Furthermore, a spinal epidural haematoma, extending from the foramen magnum down to the middle portion of the thoracic spine was found. No fractures of vertebrae nor lesions of spine ligaments or bleedings of intervertebral discs were found. Blood alcohol concentration was determined 1.92 g/l and urine alcohol concentration was 1.76 g/l. Further morphological findings were cerebral oedema and cardiac hypertrophy; the urinary bladder was found filled to bursting. Neuropathological investigations confirmed the presence of the spinal epidural haematoma and assigned lethal significance to this finding. There were no histological signs of axonal injury. Reconstruction revealed that when sitting on a chair in a drunk condition, the individual's upper part of the body had fallen backwards in the corner and subsequently got stuck with maximum anteflection of the head and cervical spine, causing rupture of vessels and spinal epidural haematoma. Acute respiratory failure caused by impairment of the phrenic nerve following spinal epidural haematoma with potential synergism of alcohol intoxication was ascertained as the cause of death. 相似文献
190.
The post-mortem blood specimens of 389 forensic autopsies were analyzed for diazepam. The age of the cases investigated was above 10 years and the survival time was less than 12 hours. Eighteen samples corresponding to 4.6% were found to be diazepam-positive. These 18 samples were distributed equally between men and women. The proportion of diazepam-positive samples was increased in the groups of suicide and poisoning (alcohol and opiates). The association between diazepam intake and poisoning was statistically highly significant. No correlation was found between diazepam intake and age. Alcohol was found to occur significantly more often in the group of the diazepam positive cases as compared to the diazepam negative group. 相似文献