全文获取类型
收费全文 | 260篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 115篇 |
晶体学 | 7篇 |
力学 | 7篇 |
数学 | 105篇 |
物理学 | 31篇 |
出版年
2023年 | 1篇 |
2022年 | 13篇 |
2021年 | 12篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 13篇 |
2012年 | 14篇 |
2011年 | 18篇 |
2010年 | 14篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 15篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 31 毫秒
71.
72.
73.
74.
Zahra Abdi Dr. Robabeh Bagheri Dr. Mohammad Reza Mohammadi Prof. Zhenlun Song Dr. Mikaela Görlin Prof. Holger Dau Prof. Dr. Mohammad Mahdi Najafpour 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(4):1330-1336
All studies on oxygen-evolution reaction by Mn oxides in the presence of cerium(IV) ammonium nitrate (CAN) have been so far carried out by synthesizing Mn oxides in the first step. And then, followed by the investigation of the Mn oxides in the presence of oxidants for oxygen-evolution reaction (OER). This paper presents a case study of a new and promising strategy for in situ catalyst synthesis by the adding MnII to either CAN or KMnO4/CAN solution, resulting in the formation of Mn-based catalysts for OER. The catalysts were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. Both compounds contained nano-sized particles that catalyzed OER in the presence of CAN. The turnover frequencies for both catalysts were 0.02 (mmol /molMn⋅s). 相似文献
75.
Fereja Tadesse Haile Kitte Shimeles Addisu Snizhko Dmytro Qi Liming Nsabimana Anaclet Liu Zhongyuan Xu Guobao 《Analytical and bioanalytical chemistry》2018,410(26):6779-6785
Analytical and Bioanalytical Chemistry - Ethyl formate is extensively used as food flavor, fungicide, and larvicide. It naturally exists in coffee, fruits, honey, brandy, and rum as well as dust... 相似文献
76.
77.
78.
An anisothermal elastoviscoplastic three-dimensional model is proposed in order to predict the response of brake discs used in the French T.G.V. (high speed train). The brake disc is subjected simultaneously to mechanical and thermal cyclic loadings by the application of brake pads to the friction surface. This anisothermal law is based on the internal thermodynamic variables and takes into account the non-linear kinematic hardening, isotropic hardening (to describe cyclic softening) and plastic strain memory effect. Cyclic viscoplastic behavior under in-phase changes of temperature and strain is analysed by using this elaborate anisothermal model with its material constants determined from isothermal experiments. Good agreement is obtained between the predictions and experiments. 相似文献
79.
S. H. Abdi Oskooie M. M. Heravi P. Khosrofar F. Faridbod 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2399-2402
Reaction of various aromatic aldehydes with 4-amino-6-methyl-1,2,4-triazin-5-one supported on to montmorillonite-K10 in the presence of nitrobenzene under microwaves irradiation, afforded the corresponding [1,3,4] thiadiazole [2,3-c][1,2,4]-triazinones. 相似文献
80.
M. R. Abdi H. R. Shakur Kh. Rezaee Ebrahim Saraee M. Sadeghi 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1217-1225
For the first time, effects of CuO nanoparticles concentration (from 1 to 24.2 wt%) in CuO/NaX nanocomposite and replacing various cations (Ag+, K+, Ca2+, and Mg2+) with Na+ ions in NaX zeolite on removal of uranium ions from drinking water are reported. The removal of uranium was performed under natural conditions of pH, laboratory temperature and the presence of competing cations and anions that are available in tap water of Isfahan city. Characterization of parent NaX zeolite and modified samples were investigated using X-ray fluorescence, X-ray powder diffraction patterns, scanning electron microscopy, and atomic absorption spectroscopy methods. Using Langmuir, Freundlich, and C-models, isotherms of equilibrium adsorption were studied. Results show the removal efficiency and distribution coefficient of NaX zeolite decrease in the presence of other competing anions and cations that exist in drinking water. But, modification of NaX zeolite with various cations and CuO nanoparticles might enhance the ability of X zeolite in removing uranium from drinking water. 相似文献