全文获取类型
收费全文 | 50篇 |
免费 | 3篇 |
国内免费 | 5篇 |
专业分类
化学 | 28篇 |
力学 | 8篇 |
数学 | 3篇 |
物理学 | 19篇 |
出版年
2015年 | 2篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 9篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1983年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 218 毫秒
51.
WolfgangKlose Amdt-PeterSchinkel 《中国颗粒学报》2004,2(3):107-112
The transport mechanisms of momentum,mass,species,and energy are invertigated in detail for the ro-tary kiln process.The residence time prediction of the granular bed is well improved by considerng differet flow patterns in the drum.Introducing a mixed flow pattern of the basic slipping and slumping behaviour has the most important effect on the improvement of the residence time prediction.The granular bed is assumed to hehave as a Bingham fluid in the active layer of the bed.The transport mechanisms of momentum,species,and energy are modelled on the basis of this assumption and using the kinetic gas theory.Additionally,a mathematical transformation is presented to save comput a-tional time.The model results of the temperature field are in very good agreement with experimental data. 相似文献
52.
53.
J. Lohmüller H. H. Bertschat H. Granzer H. Haas G. Schatz ISOLDE Collaboration PPE Division CERN CH- Geneva- Switzerland W. -D. Zeitz 《Surface science》1996,360(1-3):213-220
Chemisorption and desorption of isolated bromine adatoms on the Si(100)-(2 × 1) surface were investigated with nuclear methods. Br adsorption sites at low coverages of 10−3 monolayers (ML) were characterised by measuring the nuclear quadrupole interaction with perturbed γγ-angular correlation (PAC) of 77Br→77Se probe atoms. Below room temperature, two distinct adsorption sites for Br are revealed by PAC. One of them disappears after isochronal annealing above 300 K. The more stable probe-atom state is associated with single Br atoms saturating a dangling bond of the surface, while the less stable state is attributed to adsorption of Br at a bridge site. The potential barrier between the two adsorption sites is estimated to be 0.9(1) eV. At temperatures above 550 K, the fraction of atoms on distinct sites decreases, presumably due to surface diffusion. By measuring the γ-activity of the sample, complete desorption of the 77Br atoms was observed above 620 K. 相似文献
54.
PiaoPingYANG JianFengYU TongHaoWU GuoZongLIU TaeSunCHANG DongKooLEE DeugHeeCHO 《中国化学快报》2004,15(1):90-92
The urea decomposition property at high temperature has been used to control the pH value in the synthesis of layer compounds. The hydrotalcites of Mg-Al and Ni-Al with high crystallinity were synthesized by using this property. 相似文献
55.
In the lamellar liquid crystallization (LLC) phase of NaOL/ OLA/H2O system, the small angle X-ray diffraction measurements show that the oleic acid is solubilized in the oil layer at first and then into the amphiphile layer. The octadiene added is also located partly in the oil layer and partly in the amphiphile layer in the LLC. With the addition of octadiene as cross-Unking agent, the LLC phase of NaOL/OIA/H2O system was polymerized under the initiation of AIBN with the protection of pure nitrogen at 60℃. Most of the double bond absorption of the monomers in IR spectra disappeared after polymerization. The polymerization takes place not only in the middle of the amphiphile layer between the double bonds of NaOL or OLA and those of octadiene, but also in the oil layer of LLC between the double bonds of OLA and those of octadiene. Interlayer spacing measurements on the copolymer proved d values decreased by about 1-2 nm compared with those of the corresponding system before the polymerization, indicati 相似文献
56.
本文按Schottky方程给出热场发射微波枪阴极电流之值来确定PARMELA程序在每一时间步长内输入粒子数,使PARMELA程序能用来作热场发射微波枪电子的动力学计算,改善了把PARMELA程序不加修改直接用于热场发射微波枪计算而带来的不合理图象。 相似文献
57.
Two remarkable epimerization processes were uncovered during our pursuit of an enantioselective synthesis of(+)-aigialospirol featuring a cyclic acetal tethered ring-closing metathesis.Through modeling,we were able to turn these two unexpected epimerizations to our advantage via modeling to ensure a successful and concise total synthesis,thereby firmly establishing cyclic acetal tethered RCM as a powerful strategy in natural product synthesis.Most importantly,calculations allowed us to fully understand the ... 相似文献
58.
归头和归尾二维相关红外光谱法的鉴别研究 总被引:7,自引:3,他引:4
采用红外光谱法 (FourierTransformInfraredSpectroscopy ,FTIR)并结合二维相关 (Two dimensionalcorrelationspectroscopy)分析技术分析鉴别了来自甘肃岷县的两批当归药材各自的归头和归尾。尽管归头和归尾属于同种药材的不同药用部位 ,在红外的一维谱图上较为相似 ,但由于氨基酸和挥发油在当归的根头部分和归尾部分的分布不均一而引起二维相关红外谱的不同而可方便的加以区分鉴别。该法快速、准确 ,为客观评价中药材提供了一种新的方法和手段 相似文献