全文获取类型
收费全文 | 114篇 |
免费 | 2篇 |
国内免费 | 8篇 |
专业分类
化学 | 84篇 |
力学 | 6篇 |
综合类 | 2篇 |
数学 | 18篇 |
物理学 | 14篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 1篇 |
2006年 | 4篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有124条查询结果,搜索用时 15 毫秒
51.
Combustion instability of O2/kerosene, O2/kerosene/hydrogen, and O2/kerosene/hydro-gen spray flame is numerically studied. The numerical results of combustion self-oscillation are consistent with the historical experiments. Hydrogen is helpful to stabilizing oxygen/hydrocarbon combustion. High gas injecting velocity of the coaxial injector would increase the combustion stability. Contrary to the former expectation, the most sensitive region for combustion instability is not where the heat releases most intensely but is the low-temperature premixed region near the injectors. According to the simulation, the technology steps, such as adding catalyzer to decrease the reaction activity energy, or improving the injector design to reduce the premixed low temperature region, would improve the combustion stability. 相似文献
52.
53.
WANG Zhicong ZHANG Qinghe LI Tong ZHAO Zhongyi & ZHANG Weibing . Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China . Dalian Elite Analytical Instrument Co. Ltd. Dalian China . Faculty of Material Science Chemical Engineering China University of Geosciences Wuhan China 《中国科学B辑(英文版)》2006,49(6):527-533
A comprehensive two-dimensional liquid chromatographic system (2D SCX/RP) is con- structed with a 10-port-2-way valve using strong cation exchange chromatography (Hypersil SCX, 100 mm×4.6 mm I.D.) followed by reversed phase chromatography (Hypersil BDS C18, 15 mm×4.6 mm I.D.) to separate the complex peptides from globin peptic hydrolysate. After the sample was loaded on the SCX column, the phosphate buffer (pH 4.0) was used to elute the peptides. Then, elutes flowed through the interface and the peptides focused on the head of the trapping columns (Hypersil BDS C18, 15 mm×4.6 mm I.D.) but salt passed into the waste. After the valve was switched, the samples were flushed with a backward flow into the RP analytical column. The peptides on the SCX were eluted with 12 discontinuous steps linearly increasing salt concentrations. The peptides enriched on the trapping column were desalted and separated by the RP columns. The resolution and the resolved peaks of the 2D SCX/RP system were greatly increased and the total peak capacity reached as high as 2280. 相似文献
54.
本文对量子化学方法应用于分析化学的有机显色反应能作一综述,重点从量子化学在生色理论,在试剂络合性能研究中,在试剂质子化及其酸碱平衡和存在形成研究中以及在取代基效应的中的应用四个方面进行了论述,重点介绍我国在这一方面的工作。认为用量子化学方法预测试剂和络合物的某些性质成为可能。参考文献60篇。 相似文献
55.
稀土农用是国家经委要求的推广项目之一。石河子地区经过三年的小区试验和大面积示范,说明在春小麦的苗期、棉花的初花期喷施稀土“农乐”益植素可以收到明显的增产效果和经济效益。 相似文献
56.
57.
58.
A 5(3) pair of extended Runge–Kutta–Nyström type methods for the numerical integration of perturbed oscillators is presented. These methods are based on the order conditions of extended Runge–Kutta–Nyström type methods proposed by Yang et al. [H.L. Yang, X.Y. Wu, X. You, Y.L. Fang, Extended RKN-type methods for numerical integration of perturbed oscillators, Comput. Phys. Commun. 180 (2009) 1777–1794]. The numerical stability and phase properties of the fifth-order methods are analyzed. Numerical experiments are carried out to show the efficiency and robustness of our new methods in comparison with some well known high quality codes proposed in the scientific literature. 相似文献
59.
Alan L. Stottlemyer Thomas G. Kelly Qinghe Meng Jingguang G. Chen 《Surface Science Reports》2012,67(9-10):201-232
Historically the interest in the catalytic properties of transition metal carbides (TMC) has been inspired by their “Pt-like” properties in the transformation reactions of hydrocarbon molecules. Recent studies, however, have revealed that the reaction pathways of oxygen-containing molecules are significantly different between TMCs and Pt-group metals. Nonetheless, TMCs demonstrate intriguing catalytic properties toward oxygen-containing molecules, either as the catalyst or as the catalytically active substrate to support metal catalysts, in several important catalytic and electrocatalytic applications, including water electrolysis, alcohol electrooxidation, biomass conversion, and water gas shift reactions. In the current review we provide a summary of theoretical and experimental studies of the interaction of TMC surfaces with oxygen-containing molecules, including both inorganic (O2, H2O, CO and CO2) and organic (alcohols, aldehydes, acids and esters) molecules. We will discuss the general trends in the reaction pathways, as well as future research opportunities in surface science studies that would facilitate the utilization of TMCs as catalysts and electrocatalysts. 相似文献
60.