全文获取类型
收费全文 | 154篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
化学 | 99篇 |
晶体学 | 2篇 |
力学 | 1篇 |
数学 | 12篇 |
物理学 | 50篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 1篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 5篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
1.
Eric P. Bescher Atif Noori John D. Mackenzie 《Journal of Sol-Gel Science and Technology》2004,32(1-3):69-72
A fluorinated copolymer/metal oxide hybrid is fabricated by refluxing a high hydroxyl content fluorinated copolymer with tetraethoxysilane. The resulting organic-inorganic hybrids are transparent throughout the entire compositional range if processed with HCl as a catalyst. They exhibit a continuous variation in hardness, hydrophobicity, and abrasion resistance, intermediary between the properties of the pure polymer and that of a silica gel. The catalyst has a strong influence over the microstructure of the hybrid. 29Si MAS-NMR indicates the presence of highly condensed silica clusters within the structure of the hybrid. If a Nd(III) alkoxide is used instead of TEOS, a Nd 3+-doped fluoropolymer is obtained. These results indicate that when a fluorinated copolymer contains groups amenable to hydrolysis and condensation, cross-linking with a metal alkoxide is possible, leading to an interesting families of hybrids. 相似文献
2.
3.
Atif Ali Fan Cheng Wei-Hong Wen Xiao Ying Jaipal Kandhadi Hui Wang Hai-Yang Liu Chi-Kwong Chang 《中国化学快报》2018,29(12):1888-1892
A new bulky 2-chloro-5,10,15-tris(2,4,6-triphenylphenyl)-corrole was casually synthesized and the effect of mono-β-chlorination on its photophysical, electrochemical properties and light-induced singlet oxygen generation was investigated. 相似文献
4.
Fong-Fu Hsu Irfan J. Lodhi John Turk Clay F. Semenkovich 《Journal of the American Society for Mass Spectrometry》2014,25(8):1412-1420
We describe a linear ion-trap (LIT) multiple-stage (MSn) mass spectrometric approach towards differentiation of alkylacyl, alk-1-enylacyl- and diacyl-glycerophoscholines (PCs) as the [M – 15]– ions desorbed by electrospray ionization (ESI) in the negative-ion mode. The MS4 mass spectra of the [M – 15 – R2′CH = CO]– ions originated from the three PC subfamilies are readily distinguishable, resulting in unambiguous distinction of the lipid classes. This method is applied to two alkyl ether rich PC mixtures isolated from murine bone marrow neutrophils and kidney, respectively, to explore its utility in the characterization of complex PC mixture of biological origin, resulting in the realization of the detailed structures of the PC species, including various classes and many minor isobaric isomers. Graphical abstract
? 相似文献
5.
Ahmad VU Hussain J Hussain H Farooq U Farmanullah Lodhi MA Choudhary MI 《Natural product research》2005,19(3):267-274
Two new myrsinol-type diterpene polyesters 3,5,13,17-tetra-O-acetyl-7-O-benzoyl-15-hydroxymyrsinol (1) and 3,5,13,17-tetra-O-acetyl-7-O-butanoyl-13-hydroxymyrsinol (2), with a tricyclic carbon skeleton have been isolated from Euphorbia decipiens Boiss. & Buhse. The structure elucidation of the isolated compounds was based primarily on HREIMS, EIMS, IR, UV, ID-, and 2D-NMR analyses, including COSY, HMQC, HMBC, and NOESY correlations. Compounds 1 and 2 also showed activity against urease enzyme. 相似文献
6.
毛细管电泳具有分析时间短,分离效率高,样品消耗量少等优点,在生物样品分离,特别是蛋白质分析领域有重要应用。然而,毛细管内壁硅羟基的解离给分离结果带来诸多不良影响。聚合物涂层能够抑制蛋白质在毛细管内壁的吸附以及调控电渗流,故对毛细管内壁进行有效修饰能够提高其对蛋白质的分离效率及分离稳定性。该文主要综述了动态及静态聚合物涂层毛细管的最新研究进展,并概述了近些年基于多巴胺/聚多巴胺发展起来的涂层毛细管的研究进展,最后展望了聚合物涂层毛细管的发展趋势。 相似文献
7.
Nasir Khalid Mohammad Wasim Nadeem A. Lodhi Mohammad Arif 《Journal of Radioanalytical and Nuclear Chemistry》2013,297(1):153-159
Certified alloys of Ni–Cu based, Fe based and Cu–Sn based were analysed by semi-absolute, standardless k 0-instrumental neutron activation analysis (k 0-INAA) and flame atomic absorption spectrophotometry (FAAS) aiming at evaluating their comparative performances. In k 0-INAA measurements, the irradiations were performed at miniaturized neutron source reactor having thermal neutron flux of about 1 × 1012 cm?2 s?1. The experimentally optimized parameters for INAA suggested a maximum of three irradiations for the quantification of 21 elements within 5 days. The same experiments also produced quantitative results of 13 elements not reported in the certificates of the reference materials. AAS was, however, unable to determine any of those elements. Accuracy of the two techniques was assessed by comparing their average root mean squared errors. The data analysis concluded that k 0-INAA had better sensitivity and accuracy than FAAS. 相似文献
8.
The present study evaluates the photodynamic damage with 5-aminolevulinic acid (5-ALA) using HeLa as experimental model. HeLa
cell line was irradiated with red light (He-Ne laser, λ = 632.8 CW nm). The influence of different incubation times and concentrations
of 5-ALA, different irradiation doses and various combinations of photosensitizer and light doses on the cellular viability
of HeLa cells were studied. The optimal uptake of photosensitizer ALA in HeLa cells was investigated by means of PpIX fluorescence
intensity by exciting the HeLa cell suspension at 450 nm and a detection wavelength set at 690 nm. Cells viability was determined
by means of trypan blue solution. The spectrometric measurements showed that the maximal cellular uptake of 5-ALA occurred
after 4 h in vitro incubation. We found that the combination with 5-ALA and laser irradiation leads to time/concentration-dependent
increase of cells death and also energy doses-dependent enlarge the cells death. The fluorescence intensity after PDD of carcinoma
cells reduce when compared with the control group. The fluorescence emission spectral profiles after PDD of carcinoma cells
showed a dip around 425–525 nm when compared with the control group. This may be due to the damage of mitochondria component
of cells. The percentage of HeLa cells after PDD shows that the percentage of cells survival rate as function of laser dose
(power). Hence it is clear that at 200 μg/ml ALA and 20 mW laser irradiation, more than 70% of HeLa cells were dead after
15 min. 相似文献
9.
Study of the efficacy of photofrin®-Mediated PDT on human hepatocellular carcinoma (HepG2) cell line
Laser Physics - The present study evaluates the effects of photodynamic therapy (PDT) with Photofrin® using human liver cancer cells (HepG2) as an experimental model. We optimized the... 相似文献
10.