全文获取类型
收费全文 | 16768篇 |
免费 | 734篇 |
专业分类
各国政治 | 818篇 |
工人农民 | 639篇 |
世界政治 | 1216篇 |
外交国际关系 | 554篇 |
法律 | 10833篇 |
中国共产党 | 1篇 |
中国政治 | 91篇 |
政治理论 | 3262篇 |
综合类 | 88篇 |
出版年
2020年 | 247篇 |
2019年 | 305篇 |
2018年 | 335篇 |
2017年 | 419篇 |
2016年 | 422篇 |
2015年 | 339篇 |
2014年 | 387篇 |
2013年 | 1699篇 |
2012年 | 366篇 |
2011年 | 443篇 |
2010年 | 420篇 |
2009年 | 427篇 |
2008年 | 448篇 |
2007年 | 423篇 |
2006年 | 444篇 |
2005年 | 379篇 |
2004年 | 373篇 |
2003年 | 376篇 |
2002年 | 350篇 |
2001年 | 683篇 |
2000年 | 608篇 |
1999年 | 476篇 |
1998年 | 268篇 |
1997年 | 217篇 |
1996年 | 188篇 |
1995年 | 176篇 |
1994年 | 213篇 |
1993年 | 197篇 |
1992年 | 306篇 |
1991年 | 349篇 |
1990年 | 332篇 |
1989年 | 331篇 |
1988年 | 330篇 |
1987年 | 331篇 |
1986年 | 366篇 |
1985年 | 342篇 |
1984年 | 284篇 |
1983年 | 278篇 |
1982年 | 185篇 |
1981年 | 202篇 |
1980年 | 147篇 |
1979年 | 242篇 |
1978年 | 155篇 |
1977年 | 139篇 |
1976年 | 119篇 |
1975年 | 115篇 |
1974年 | 155篇 |
1973年 | 140篇 |
1972年 | 114篇 |
1971年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Vogel JS Parker JR Jordan FB Coury TL Vernino AR 《The American journal of forensic medicine and pathology》2000,21(3):264-269
The authors report a fatal case of a Persian leopard (Panthera pardus) attack in an animal sanctuary in Oklahoma. The victim was a 53-year-old Costa Rican woman who was attempting to feed the animal when she was attacked and killed. Autopsy, radiography, fingerprint analysis, microbiologic cultures, and dental impressions were used to evaluate the case. These simple techniques can be applied to similar cases involving wild and domestic animal attacks. 相似文献
982.
Morphine-3-D glucuronide stability in postmortem specimens exposed to bacterial enzymatic hydrolysis
Carroll FT Marraccini JV Lewis S Wright W 《The American journal of forensic medicine and pathology》2000,21(4):323-329
Medical examiners frequently rely on the finding of free morphine present in postmortem specimens to assist in certifying deaths associated with narcotics. In vitro hydrolysis of morphine-3-D glucuronide (M3DG) to free morphine was studied using variable specimen pH, initial degree of specimen putrefaction, storage temperature and time, and the effectiveness of sodium fluoride (NaF) preservation. Reagent M3DG was added to opiate-free fresh blood and urine and to autopsy-derived blood specimens. Reagent bovine glucuronidase was also added to certain specimens. Freshly collected and refrigerated NaF-preserved blood produced minimal free morphine, whereas four of five autopsy blood specimens produced free morphine from M3DG. Increased storage time, temperature, and initial degree of putrefaction resulted in greater free morphine generation despite the absence of viable bacteria. Hydrolysis occurring during specimen storage can generate free morphine from M3DG and may result in erroneous conclusions in certifying narcotic deaths. 相似文献
983.
984.
Stereolithography is a computer-mediated method that can be used to quickly create anatomically correct three-dimensional epoxy and acrylic resin models from various types of medical data. Multiple imaging modalities can be exploited, including computed tomography and magnetic resonance imaging. The technology was first developed and used in 1986 to overcome limitations in previous computer-aided manufacturing/milling techniques. Stereolithography is presently used to accurately reproduce both the external and internal anatomy of body structures. Current medical uses of stereolithography include preoperative planning of orthopedic and maxillofacial surgeries, the fabrication of custom prosthetic devices; and the assessment of the degree of bony and soft-tissue injury caused by trauma. We propose that there is a useful, as yet untapped, potential for this technology in forensic medicine. 相似文献
985.
Gruszecki AC Robinson CA Embry JH Davis GG 《The American journal of forensic medicine and pathology》2000,21(2):166-171
Hair samples are useful as a matrix for drug testing because drugs can be detected in hair for longer periods than in blood or urine. The authors report a prospective comparison of the detection of cocaine and cocaethylene in routine postmortem biologic specimens to the detection of cocaine and cocaethylene in hair. The authors collected hair samples from various areas of the head in 53 autopsy cases, prepared them, and analyzed them by gas chromatography/mass spectrometry (GC/MS) for cocaine and cocaethylene. The authors compared the results of hair analysis with the results of toxicologic analysis performed on routine postmortem samples by enzyme multiplied immunoassay technique and GC/MS. Cocaine was found in either biologic fluids or in hair in 16 of 53 samples tested. Nine samples were positive for cocaine in both biologic fluids and hair. Five samples contained cocaine only in biologic fluids, and two contained cocaine only in hair. Cocaethylene was present in two cases. Drug screening of hair provides additional information in some autopsy cases, but the authors have not made hair analysis a routine practice. It may prove useful to save hair samples in all cases for later analysis if warranted by additional history or autopsy findings. 相似文献
986.
987.
988.
Steadman HJ Silver E Monahan J Appelbaum PS Robbins PC Mulvey EP Grisso T Roth LH Banks S 《Law and human behavior》2000,24(1):83-100
Since the 1970s, a wide body of research has suggested that the accuracy of clinical risk assessments of violence might be increased if clinicians used actuarial tools. Despite considerable progress in recent years in the development of such tools for violence risk assessment, they remain primarily research instruments, largely ignored in daily clinical practice. We argue that because most existing actuarial tools are based on a main effects regression approach, they do not adequately reflect the contingent nature of the clinical assessment processes. To enhance the use of actuarial violence risk assessment tools, we propose a classification tree rather than a main effects regression approach. In addition, we suggest that by employing two decision thresholds for identifying high- and low-risk cases--instead of the standard single threshold--the use of actuarial tools to make dichotomous risk classification decisions may be further enhanced. These claims are supported with empirical data from the MacArthur Violence Risk Assessment Study. 相似文献
989.
990.
Gusmão L González-Neira A Sánchez-Diz P Lareu MV Amorim A Carracedo A 《Forensic science international》2000,112(1):49-57
The amplification of the STR DYS391, using the primers described in the Genome Data Base (GDB: G00-365-251), shows not only an additional band to the Y-specific one in males with a size range of 26 bp less than those of DYS391 locus alleles, but also a polymorphic pattern in females in the same size range as the additional band observed in males. The DYS391 pattern in families reflects a Y-specific linked locus and also a polymorphic X locus with an X-linked pattern of inheritance. A first screening in the X homologous locus allowed the identification of five different alleles. Allele frequencies were explored in different population groups for both the Y locus and the homologous locus in the X chromosome showing a similar allele distribution pattern in the X and Y homologous loci. An alternative reverse primer was designed to amplify the Y-chromosome specific STR in order to improve the specificity and applicability of this system to forensic genetics. Comparative results of the amplification with the new and the previously described primers proved that with this new primer there is a substantial increase in the specificity of the amplification. Moreover, a smaller fragment is amplified with a size out of the range of the alleles of the other Y-STRs usually used in forensic applications, therefore simplifying its inclusion in multiplex systems. 相似文献