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351.
Abstract: This study presents a new method for understanding postmortem heat-induced crack propagation patterns in teeth. The results demonstrate that patterns of postmortem heat-induced crack propagation differ from perimortem and antemortem trauma-induced crack propagation patterns. Dental material of the postmortem tooth undergoes dehydration leading to a shrinking and more brittle dentin material and a weaker dentin-enamel junction. Dentin intertubule tensile stresses are amplified by the presence of the pulp cavity, and initiates crack propagation from the internal dentin, through the dentin-enamel junction and lastly the enamel. In contrast, in vivo perimortem and antemortem trauma-induced crack propagation initiates cracking from the external surface of the enamel toward the dentin-enamel junction where the majority of the energy of the crack is dissipated, eliminating the crack’s progress into the dentin. These unique patterns of crack propagation can be used to differentiate postmortem taphonomy-induced damage from antemortem and perimortem trauma in teeth. 相似文献
352.
Abstract: Although the ophthalmoscope was invented by Hermann von Helmholtz in 1851, pathologists until recently have relied almost exclusively on ocular enucleation to identify and describe postmortem fundal abnormalities. An inexpensive but valuable tool for forensic pathologists, the postmortem monocular indirect ophthalmoscope consists of a light source attached to a headband along with a hand-held lens. This permits a wide view of the fundus after death but the technique can be challenging to master for pathology residents and forensic pathology fellows. To facilitate skill acquisition in monocular indirect ophthalmoscopy, a simple and inexpensive teaching model can be constructed from hinged, cylindrical plastic containers. An artificial pupil created in the lid and a removable color fundal image placed in the bottom of the opaque container allows the pathologist-in-training to practice the technique of monocular indirect ophthalmoscopy and correctly identify, localize, and describe fundal abnormalities such as retinal hemorrhages. 相似文献
353.
354.
Mast cell histochemistry has been proposed in addition to classic histological methods to estimate the course of traumatic events before and after death. We have addressed the utility of this approach on nine victims of different types of trauma. Sections of wounded skin were stained with hematoxylin and eosin and with fluorescent avidin to tag mast cells. Mast cell numbers were evaluated by both direct and digitalized counts. Intact skin was used as control. The results on mast cells implemented the findings upon hematoxylin and eosin stain and helped to put the wounds and death in chronological sequence. Digitalized morphometry allowed to reduce intra- and inter-observer variation. We conclude that combined histological and histochemical analyses can be of practical use in forensic pathology, that a preliminary setting of the reference values is needed for each laboratory, and that image analysis can be of help for the quantification of the results. 相似文献
355.
The "coffin fly,"Conicera tibialis Schmitz (Order: Diptera, Family: Phoridae), is well known for its frequent occurrence on buried corpses, in some cases after postmortem intervals of even 3-5 years. The present report describes the presence of a large amount of individuals of C. tibialis inside the coffin of a buried human corpse exhumed 18 years after death in central Spain. Adults, some of them newly emerged, and empty puparia were found in connection with the remains. Such postmortem interval is significantly longer than previously known for this species and raises the question on the current state of knowledge about the use of insects for estimating the postmortem interval in old, buried remains. 相似文献
356.
Christian Jackowski M.D. Marcel J. B. Warntjes Ph.D. Johan Kihlberg R.N. Johan Berge M.D. Michael J. Thali M.D. Anders Persson M.D. 《Journal of forensic sciences》2011,56(1):208-215
Abstract: A quantification of T1, T2, and PD in high isotropic resolution was performed on corpses. Isotropic and quantified postmortem magnetic resonance (IQpmMR) enables sophisticated 3D postprocessing, such as reformatting and volume rendering. The body tissues can be characterized by the combination of these three values. The values of T1, T2, and PD were given as coordinates in a T1–T2–PD space where similar tissue voxels formed clusters. Implementing in a volume rendering software enabled color encoding of specific tissues and pathologies in 3D models of the corpse similar to computed tomography, but with distinctively more powerful soft tissue discrimination. From IQpmMR data, any image plane at any contrast weighting may be calculated or 3D color‐encoded volume rendering may be carried out. The introduced approach will enable future computer‐aided diagnosis that, e.g., checks corpses for a hemorrhage distribution based on the knowledge of its T1–T2–PD vector behavior in a high spatial resolution. 相似文献
357.
利用尸体软组织生物力学性状时序性变化推断死亡时间 总被引:1,自引:1,他引:0
目的探讨尸体软组织生物力学性状时序性变化规律及其推断死亡时间的可行性。方法将实验大鼠用颈椎脱臼法处死,放置25℃恒温培养箱内即刻、6、12、18、24、30、36、42、48、60、72、96、120、144、168、192h,定时、定位、定向、定形切取大鼠胸部正中皮肤、腹壁肌肉、胸主动脉、结肠和小肠的生物力学试件,用电子万能材料试验机检测各试件的极限载荷、应变、应力生物力学参数。结果除主动脉外,尸体皮肤、肌肉、小肠、结肠的各项软组织生物力学参数均呈明显的死后时序性下降趋势。各参数下降趋势具有显著性差异的"窗口期"分别为:极限载荷:死后18h内皮肤、小肠呈下降趋势;24h内肌肉、结肠呈下降趋势;96~168h肌肉呈下降趋势;72~192h结肠呈下降趋势。应变:各组织在24h内均呈下降趋势,其结肠72~192h缓慢下降趋势。应力:皮肤18h内呈下降趋势,肌肉、小肠24h内呈下降趋势,结肠36h内呈下降趋势。结论大鼠尸体软组织各生物力学性状在不同的"窗口期"存在时序性变化规律,综合各指标可用于推断相应"窗口期"内的死亡时间。 相似文献
358.
运用再现理论对《人民日报》、《新民晚报》、《羊城晚报》的历史研究发现,媒体建构的农民工群体正在蜕去早期的形象,经历着从都市"边缘人"到成长中的"新市民"的时代嬗变。这对于正确认识真实的农民工群体,正确认识城市化过程中的客观表象及背后的社会心理变迁,揭示大众传媒助推农民工融入城市的作用具有重要意义。 相似文献
359.
360.
Ruder TD Hatch GM Ebert LC Flach PM Ross S Ampanozi G Thali MJ 《Journal of forensic sciences》2012,57(3):778-782
Computed tomography (CT) and magnetic resonance (MR) imaging have become important elements of forensic radiology. Whereas the feasibility and potential of CT angiography have long been explored, postmortem MR angiography (PMMRA) has so far been neglected. We tested the feasibility of PMMRA on four adult human cadavers. Technical quality of PMMRA was assessed relative to postmortem CT angiography (PMCTA), separately for each body region. Intra-aortic contrast volumes were calculated on PMCTA and PMMRA with segmentation software. The results showed that technical quality of PMMRA images was equal to PMCTA in 4/4 cases for the head, the heart, and the chest, and in 3/4 cases for the abdomen, and the pelvis. There was a mean decrease in intra-aortic contrast volume from PMCTA to PMMRA of 46%. PMMRA is technically feasible and allows combining the soft tissue detail provided by MR and the information afforded by angiography. 相似文献