全文获取类型
收费全文 | 303篇 |
免费 | 7篇 |
国内免费 | 3篇 |
专业分类
化学 | 244篇 |
晶体学 | 4篇 |
力学 | 15篇 |
数学 | 5篇 |
物理学 | 45篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 12篇 |
2021年 | 19篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 12篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 21篇 |
2013年 | 26篇 |
2012年 | 32篇 |
2011年 | 43篇 |
2010年 | 25篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 13篇 |
2004年 | 10篇 |
2003年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有313条查询结果,搜索用时 0 毫秒
31.
Tae Kyu Kim Euh Duck Jeong Chae Young Oh Min Seob Shin Jong-Pil Kim Ok-Sang Jung Hongsuk Suh Fazlur Rahman Nawaz Khan Myung Ho Hyun Jong Sung Jin 《Chemical Papers》2011,65(6):863-872
A series of neutral gelators and cationic amphiphiles derived from 1,2 diphenylethylenediamine (I) and 1,2-cyclohexanediamine (II) was synthesised. Helical silica nanotubes were prepared utilising these organic gelators through sol-gel polycondensation
of tetraethoxy silane, (TEOS-silica source). Right- and left-handed helical nanotubes respectively were obtained from a 1:
1 mass mixture of optically active, (1S,2S)-III-(1S,2S)-V neutral gelator and (1S,2S)-IV-(1S,2S)-VI cationic amphiphile and a 1: 1 mass mixture of optically active, (1R,2R)-III-(1R,2R)-V neutral gelator and (1R,2R)-IV-(1R,2R)-VI cationic amphiphile, indicating that the handedness of the helical nanotubes varied with the change in the neutral gelator
precursors used. The nanotubes were characterised by SEM images. 相似文献
32.
André R Tahir MN Link T Jochum FD Kolb U Theato P Berger R Wiens M Schröder HC Müller WE Tremel W 《Langmuir : the ACS journal of surfaces and colloids》2011,27(9):5464-5471
In nature, mineralization of hard tissues occurs due to the synergistic effect of components present in the organic matrix of these tissues, with templating and catalytic effects. In Suberites domuncula, a well-studied example of the class of demosponges, silica formation is mediated and templated by an axial proteinaceous filament with silicatein-α, one of the main components. But so far, the effect of other organic constituents from the proteinaceous filament on the catalytic effect of silicatein-α has not been studied in detail. Here we describe the synthesis of core-shell TiO(2)@SiO(2) and TiO(2)@ZrO(2) nanofibers via grafting of silicatein-α onto a TiO(2) nanowire backbone followed by a coassembly of silintaphin-1 through its specifically interacting domains. We show for the first time a linker-free, one-step funtionalization of metal oxides with silicatein-α using glutamate tag. In the presence of silintaphin-1 silicatein-α facilitates the formation of a dense layer of SiO(2) or ZrO(2) on the TiO(2)@protein backbone template. The immobilization of silicatein-α onto TiO(2) probes was characterized by atomic force microscopy (AFM), optical light microscopy, and high-resolution transmission electron microscopy (HRTEM). The coassembly of silicatein-α and silintaphin-1 may contribute to biomimetic approaches that pursue a controlled formation of patterned biosilica-based biomaterials. 相似文献
33.
Selvaraj Mohana Roopan F. Nawaz Khan Jong Sung Jin R. Senthil Kumar 《Research on Chemical Intermediates》2011,37(8):919-927
Montmorillonite K10 efficiently catalyzed a one pot–three component cyclocondensation of isatoic anhydride, NH4OAc and aromatic/heteroaromatic aldehydes under ambient conditions to produce the corresponding 2-substituted-2,3-dihydroquinazolin-4(1H)-ones
in good yields. The 2-(2-chloroquinolin-3-yl)-2,3-dihydroquinazolin-4(1H)-ones 3a–d were screened for their antitumor activity against Ehrlich Ascites Carcinoma tumor cells 相似文献
34.
Abid OU Nawaz M Ibad MF Khera RA Iaroshenko V Langer P 《Organic & biomolecular chemistry》2011,9(7):2185-2191
Aryl-substituted pyridines and pyrimidines were prepared by [4+2] cycloadditions of alkynyl-substituted pyridines and -pyrimidines with electron-rich dienes. The reactions proceed by formation of a bridged cycloadduct and subsequent thermal extrusion of ethylene. The pyridine moiety plays a crucial role for the success of the reaction. 相似文献
35.
Cyclic peptoids were efficiently synthesized on a solid phase in high yields utilizing ring-closing metathesis (RCM). This method should be a valuable tool for easy access to cyclic peptoid libraries and various cyclic compounds. 相似文献
36.
37.
Berry DJ Ma Y Ballinger JR Tavaré R Koers A Sunassee K Zhou T Nawaz S Mullen GE Hider RC Blower PJ 《Chemical communications (Cambridge, England)》2011,47(25):7068-7070
A new tripodal tris(hydroxypyridinone) bifunctional chelator for gallium allows easy production of (68)Ga-labelled proteins rapidly under mild conditions in high yields at exceptionally high specific activity and low concentration. 相似文献
38.
Shahid Hussain Arshad Muhammad Nawaz Naeem Nazra Sultana Zafar Iqbal Abdul Ghafar Shah 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(8):999-1016
In the present work, vibration characteristics of thin functionally graded cylindrical shells are studied under the influence
of various boundary conditions. Fabrication of FGM cylindrical shell is carried out by using exponential volume fraction law.
Strain- and curvature-displacements relationships are taken from Love’s thin shell theory. The frequency equation in the form
of eigenvalue problem is obtained by adapting the Rayleigh-Ritz method. Characteristic beam functions are assumed to approximate
the axial modal dependence. Effects of exponential volume fraction law on the natural frequencies of the FGM cylindrical shells
for various boundary conditions are studied against circumferential wave number, length to radius ratio and thickness to radius
ratio for different values of power law exponents. Results evaluated show good agreement with those available in the literature. 相似文献
39.
Muhammad Khurram Tufail Adeel Ahmed Muhammad Rafiq Muhammad Asif Nawaz Syed Shoaib Ahmad Shah Manzar Sohail Muhammad Sufyan Javed Tayyaba Najam Raed H. Althomali Mohammed M. Rahman 《Chemical record (New York, N.Y.)》2024,24(1):e202300155
In recent years, flexible and wearable electronics such as smart cards, smart fabrics, bio-sensors, soft robotics, and internet-linked electronics have impacted our lives. In order to meet the requirements of more flexible and adaptable paradigm shifts, wearable products may need to be seamlessly integrated. A great deal of effort has been made in the last two decades to develop flexible lithium-ion batteries (FLIBs). The selection of suitable flexible materials is important for the development of flexible electrolytes self-supported and supported electrodes. This review is focused on the critical discussion of the factors that evaluate the flexibility of the materials and their potential path toward achieving the FLIBs. Following this analysis, we present how to evaluate the flexibility of the battery materials and FLIBs. We describe the chemistry of carbon-based materials, covalent-organic frameworks (COFs), metal-organic frameworks (MOFs), and MXene-based materials and their flexible cell design that represented excellent electrochemical performances during bending. Furthermore, the application of state-of-the-art solid polymer and solid electrolytes to accelerate the development of FLIBs is introduced. Analyzing the contributions and developments of different countries has also been highlighted in the past decade. In addition, the prospects and potential of flexible materials and their engineering are also discussed, providing the roadmap for further developments in this fast-evolving field of FLIB research. 相似文献
40.
Rafiq Shahid Abbas Zaheer Nawaz Muhammad Alharbi Sayer Obaid 《Journal of Thermal Analysis and Calorimetry》2021,145(6):3269-3279
Journal of Thermal Analysis and Calorimetry - A numerical model is developed to study the effects of temperature-dependent viscosity on heat transfer in magnetohydrodynamic flow of micropolar fluid... 相似文献