全文获取类型
收费全文 | 580篇 |
免费 | 20篇 |
国内免费 | 6篇 |
专业分类
化学 | 433篇 |
晶体学 | 3篇 |
力学 | 11篇 |
数学 | 38篇 |
物理学 | 121篇 |
出版年
2024年 | 3篇 |
2023年 | 4篇 |
2022年 | 18篇 |
2021年 | 15篇 |
2020年 | 28篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 21篇 |
2016年 | 20篇 |
2015年 | 19篇 |
2014年 | 22篇 |
2013年 | 45篇 |
2012年 | 43篇 |
2011年 | 36篇 |
2010年 | 35篇 |
2009年 | 36篇 |
2008年 | 42篇 |
2007年 | 26篇 |
2006年 | 21篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 11篇 |
1998年 | 9篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1947年 | 1篇 |
排序方式: 共有606条查询结果,搜索用时 15 毫秒
601.
V.D. Patake S.M. Pawar V.R. Shinde T.P. Gujar C.D. Lokhande 《Current Applied Physics》2010,10(1):99-103
In the present study, ruthenium oxide (RuO2) thin films were deposited on the stainless steel (s.s.) substrates by anodic deposition. The nucleation and growth mechanism of electrodeposited RuO2 film has been studied by cyclic voltammetry (CV) and chronoamperometry (CA). The deposited films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive analysis by X-rays (EDAX) for structural, morphological, and compositional studies. The electrochemical supercapacitor study of ruthenium oxide thin films have been carried out for different film thicknesses in 0.5 M H2SO4 electrolyte. The highest specific capacitance was found to be 1190 F/g for 0.376 mg/cm2 film thickness. 相似文献
602.
Polycrystalline soft ferrite samples with general formula ZnNdxFe2−xO4 (where x=0, 0.01, 0.02 and 0.03) were synthesized by oxalate co-precipitation method. The samples were characterized by XRD and SEM techniques. The single phase cubic spinel structure of all the samples was confirmed by XRD. The lattice constant and grain size of the samples are found to decrease with increase in Nd3+ content. Room temperature DC resistivity of the Nd3+ substituted zinc ferrites is 102 times higher than that of zinc ferrite. The dielectric constant (ε′) and dielectric loss (tan δ) of all the samples were measured in the frequency range 20 Hz-1 MHz. The dielectric behaviour is attributed to the Maxwell-Wagner type interfacial polarization. The dielectric loss of the samples is found to decrease with increase in Nd3+ content. High resistivity and low dielectric loss makes these ferrites particularly suitable for high frequency applications. 相似文献
603.
Synthesis of three novel phenyl(1H-benzoimidazol-5-yl)methanone based fluorescent monoazo disperse dyes and their characterization by spectroscopic methods (1H NMR, 13C NMR, IR and MS) are presented. Insertion of phenyl(1H-benzoimidazol-5-yl)methanone moiety bring about induced fluorescence properties and enhanced photostability as compared to the previously reported analogues (CI Solvent Yellow 14, 4-diethylamino-2-hydroxy-1-diazobenzene and 7-(diethylamino)-4-hydroxy-3-(phenyldiazenyl)-2H-chromen-2-one). Synthesized phenyl(1H-benzoimidazol-5-yl)methanone based dyes exhibited red-shifted absorption maxima (497–516 nm), high molar extinction coefficients and are emitting in the far-red region (565–627 nm). Moreover, naphthalene-comprising dyes showed negative solvatochromism while N,N-diethylamine comprising dyes showed positive solvatochromism and are in good agreement with solvent polarity graphs and the computed energy levels of highest occupied and lowest unoccupied molecular orbitals. Synthesised dyes have better photostability (light fastness) and sublimation fastness on dyed polyester and nylon compared to reported analogues. DFT calculated energies, electrophilicity index and Frontier Molecular Orbitals (FMO’s) enabled to evaluate the stabilities of azo and hydrazone forms of the dyes. 相似文献
604.
Amol H. Kategaonkar Rajkumar U. Pokalwar Sandip A. Sadaphal Pravin V. Shinde Bapurao B. Shingate Murlidhar S. Shingare 《Heteroatom Chemistry》2009,20(7):436-441
A simple and convenient method is developed for the synthesis of new O,O‐diethyl O‐(substituted tetrazolo[1,5‐a]quinolin‐4‐yl)methyl phosphorothioates, which has been synthesized for the first time from tetrazolo[1,5‐a] quinolines via tetrazolo[1,5‐a]quinolin‐4‐ylmethanol derivatives. The structures of the all newly synthesized compounds were elucidated by analytical and spectral methods. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:436–441, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20570 相似文献
605.
Gadge Sandhya Tamboli Ashif Shinde Manish Fouad Hassan Terashima Chiaki Chauhan Ratna Gosavi Suresh 《Journal of Solid State Electrochemistry》2023,27(8):2005-2015
Journal of Solid State Electrochemistry - The industrial revolution has raised major concern of environmental pollution, due to excess release of hazardous chemical, dyes, etc. into water bodies.... 相似文献
606.