全文获取类型
收费全文 | 116篇 |
免费 | 12篇 |
国内免费 | 27篇 |
专业分类
化学 | 88篇 |
力学 | 28篇 |
综合类 | 1篇 |
数学 | 14篇 |
物理学 | 24篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 7篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 11篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2000年 | 2篇 |
1999年 | 8篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 265 毫秒
11.
12.
CAD软件在工程地质三维建模中的应用 总被引:3,自引:0,他引:3
如何快速、准确地建立地质体的三维模型一直是众多岩土工程数值模拟工作者所面临的难题。虽然三维地学模拟软件具有很好的三维地质建模能力,但是由于数据结构的差异,采用他们现行三维地学模拟软件建立的地质模型难以导入数值模拟分析软件中,以为相应工程问题的数值模拟服务。目前,随着各种CAD、CAM软件行业的的飞速发展,涌现出了许多优秀的三维建模软件,而且这些软件大都与现行数值分析软件有着良好的数据接口功能。据此,本文提出了采用现行CAD软件来建立工程地质体的三维模型,使得建立的模型达到既"可视"又"可算"的目的。将其应用于云南某高速公路边坡的三维建模中,证明了该法具有方便、快捷和合理等优点。 相似文献
13.
14.
Cyclometalated Iridium(III) Complexes as Two‐Photon Phosphorescent Probes for Specific Mitochondrial Dynamics Tracking in Living Cells 下载免费PDF全文
Chengzhi Jin Jiangping Liu Dr. Yu Chen Leli Zeng Ruilin Guan Cheng Ouyang Prof. Liangnian Ji Prof. Dr. Hui Chao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12000-12010
Five cyclometalated iridium(III) complexes with 2‐phenylimidazo[4,5‐f][1,10]phenanthroline derivatives ( IrL1 – IrL5 ) were synthesized and developed to image and track mitochondria in living cells under two‐photon (750 nm) excitation, with two‐photon absorption cross‐sections of 48.8–65.5 GM at 750 nm. Confocal microscopy and inductive coupled plasma‐mass spectrometry (ICP‐MS) demonstrated that these complexes selectively accumulate in mitochondria within 5 min, without needing additional reagents for membrane permeabilization, or replacement of the culture medium. In addition, photobleaching experiments and luminescence measurements confirmed the photostability of these complexes under continuous laser irradiation and physiological pH resistance. Moreover, results using 3D multicellular spheroids demonstrate the proficiency of these two‐photon luminescent complexes in deep penetration imaging. Two‐photon excitation using such novel complexes of iridium(III) for exclusive visualization of mitochondria in living cells may substantially enhance practical applications of bioimaging and tracking. 相似文献
15.
基于数字图像的土、岩和混凝土内部结构定量分析和力学数值计算的研究进展 总被引:4,自引:0,他引:4
土、岩及混凝土是一种内部结构极其复杂的材料,内部细观组成和结构决定了它们在外力作用下内部应力和应变等物理场的分布状态,在很大程度上控制了它们的宏观力学响应和破坏机理和过程。自1995年以来,数字图像处理技术作为一种材料细观空间结构及几何形态的精确量测和数字表述手段快速地被应用于沥青混凝土、水泥混凝土、土和岩体材料细观结构定量分析中来。本文在研究相关文献的基础上,分析和研究了数字图像技术在土、岩及混凝土内部结构定量分析和力学数值计算中的发展过程和研究成果,内容包括:单个骨料颗粒形态特征定量分析;土、岩和混凝土内部结构定量分析;岩体结构定量分析中的应用;基于数字图像处理的土、岩和混凝土细观结构力学计算。在此基础上,本文进一步对数字图像技术在岩土领域中的应用进展及未来的发展趋势进行了探讨,认为数字图像作为一种空间分布测量手段和数字表述方法使得它具有巨大的潜力,特别是在岩土领域的纵深发展过程中,它可能实现考虑细微观结构性的岩土力学和工程分析和预测的、新的方法和理论。 相似文献
16.
17.
18.
Dr. Lina Xie Dr. Le Shi Dr. Kai Xiong Dr. Ruilin Guan Prof. Dr. Yu Chen Prof. Dr. Jiangang Long Prof. Liangnian Ji Prof. Dr. Hui Chao 《欧洲无机化学杂志》2023,26(15):e202300001
Two novel unsymmetrical Ir(III) complexes [Ir(ppy)2(N N)Cl2] (N N=2-(pyrazin-2-yl)naphtha[1,2-e][1,2,4]triazine, Ir1 ; 2-(pyrazin-2-yl)-4b,4b’-dihydroaceanthryleno[1,2-e][1,2,4]triazine, Ir2 ) were developed as chemotherapy agents. Ir1 was mainly located in mitochondria. In contrast, Ir2 accumulated in mitochondria but subsequently migrated to the nucleus. Ir1 and Ir2 showed cytotoxicity toward cancerous cells, especially the cisplatin-resistant ones, indicating their ability to overcome cisplatin resistance. Although both Ir1 and Ir2 disrupted mitochondrial metabolism, they showed different cell death mechanisms. Ir1 induced mitochondria-mediated apoptosis in cisplatin-resistant A549R cells. Ir2 was demonstrated to cause PARP-1 activated necroptosis in A549R cells. This study provides an experimental basis for the rational design of metal-based chemotherapeutic drugs. 相似文献
19.
A new low-molecular-weight antibacterial dye was obtained by reaction of Reactive Blue 19 and chitosan previously hydrolyzed with H2O2. The compounds were characterized by Fourier-transform infrared spectroscopy, 13C solid-state nuclear magnetic resonance, X-ray photoelectron spectroscopy, X-ray diffraction analysis, and antibacterial, solubility, and dyeing performance tests including color difference and fastness. The results show that chitosan dyes were generated with covalent bonds between carbon and nitrogen atoms via reaction of alkene group of dye and primary amine group of chitosan. According to solubility tests, the solubility of the chitosan dye was controlled by the molecular weight of chitosan. In addition, compared with Reactive Blue 19, the antibacterial property of the chitosan dye was increased against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Besides, chitosan dye demonstrated better lightfastness and waterfastness than the original dye. Therefore, chitosan dye provides a new perspective for improving decorative and antimicrobial properties of wood products. 相似文献
20.
Differentiation of essential oils in Atractylodes lancea and Atractylodes koreana by gas chromatography with mass spectrometry 下载免费PDF全文
Qiutao Liu Shanshan Zhang Xihui Yang Ruilin Wang Weiying Guo Weijun Kong Meihua Yang 《Journal of separation science》2016,39(24):4773-4780
Atractylodes rhizome is a valuable traditional Chinese medicinal herb that comprises complex several species whose essential oils are the primary pharmacologically active component. Essential oils of Atractylodes lancea and Atractylodes koreana were extracted by hydrodistillation, and the yield was determined. The average yield of essential oil obtained from A. lancea (2.91%) was higher than that from A. koreana (2.42%). The volatile components of the essential oils were then identified by a gas chromatography with mass spectrometry method that demonstrated good precision. The method showed clear differences in the numbers and contents of volatile components between the two species. 41 and 45 volatile components were identified in A. lancea and A. koreana, respectively. Atractylon (48.68%) was the primary volatile component in A. lancea, while eudesma‐4(14)‐en‐11‐ol (11.81%) was major in A. koreana. However, the most significant difference between A. lancea and A. koreana was the major component of atractylon and atractydin. Principal component analysis was utilized to reveal the correlation between volatile components and species, and the analysis was used to successfully discriminate between A. lancea and A. koreana samples. These results suggest that different species of Atractylodes rhizome may yield essential oils that differ significantly in content and composition. 相似文献