全文获取类型
收费全文 | 60篇 |
免费 | 0篇 |
专业分类
化学 | 38篇 |
晶体学 | 8篇 |
物理学 | 14篇 |
出版年
2013年 | 1篇 |
2012年 | 5篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 6篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有60条查询结果,搜索用时 218 毫秒
31.
A paper chromatographic method is described for the identification of the volatile fatty acids and some of their bromo- and iodo-derivatives. Some new spraying reagents are suggested which enable the different classes of acids to be detected in presence of one another. 相似文献
32.
Thermoanalytical techniques have been used to investigate the oxidative thermal degradation of polypropylene with special reference to the inhibiting effects of certain metal chelates. The inhibiting efficiency, defined in terms of the difference in temperature between the melting point of the polymer and the temperature of onset of exothermic oxygen uptake, has been determined for each additive using differential thermal analysis (DTA). The exothermicity of polypropylene oxidation has also been estimated. 相似文献
33.
AK Leung IM Hafez S Baoukina NM Belliveau IV Zhigaltsev E Afshinmanesh DP Tieleman CL Hansen MJ Hope PR Cullis 《The journal of physical chemistry. C, Nanomaterials and interfaces》2012,116(34):18440-18450
Lipid nanoparticles (LNP) containing ionizable cationic lipids are the leading systems for enabling therapeutic applications of siRNA; however, the structure of these systems has not been defined. Here we examine the structure of LNP siRNA systems containing DLinKC2-DMA(an ionizable cationic lipid), phospholipid, cholesterol and a polyethylene glycol (PEG) lipid formed using a rapid microfluidic mixing process. Techniques employed include cryo-transmission electron microscopy, (31)P NMR, membrane fusion assays, density measurements, and molecular modeling. The experimental results indicate that these LNP siRNA systems have an interior lipid core containing siRNA duplexes complexed to cationic lipid and that the interior core also contains phospholipid and cholesterol. Consistent with experimental observations, molecular modeling calculations indicate that the interior of LNP siRNA systems exhibits a periodic structure of aqueous compartments, where some compartments contain siRNA. It is concluded that LNP siRNA systems formulated by rapid mixing of an ethanol solution of lipid with an aqueous medium containing siRNA exhibit a nanostructured core. The results give insight into the mechanism whereby LNP siRNA systems are formed, providing an understanding of the high encapsulation efficiencies that can be achieved and information on methods of constructing more sophisticated LNP systems. 相似文献
34.
M.A. Migliorato M.J. Steer W.M. Soong C.M. Tey H-Y. Liu S.L. Liew P. Navaretti D.J. Norris A.G. Cullis M. Hopkinson 《Physica E: Low-dimensional Systems and Nanostructures》2005,26(1-4):124
We discuss a novel approach to the optimisation of quantum dot bilayer structures grown by molecular beam epitaxy. Use of a kinetic segregation model has shown that a reduction of the In composition for the upper layer of a bilayer structure can be used to compensate for the excess In that exists on the surface prior to growth. Three samples have been grown with upper dot In compositions varying from 90% to 100% and have been investigated by means of optical spectroscopy and electron microscopy. 相似文献
35.
D. J. Paul S. A. Lynch R. Bates Z. Ikonic R. W. Kelsall P. Harrison D. J. Norris S. L. Liew A. G. Cullis P. Murzyn C. Pidgeon D. D. Arnone D. J. Robbins 《Physica E: Low-dimensional Systems and Nanostructures》2003,16(3-4):309
Intersubband electroluminescence results are presented from Si/SiGe quantum cascade emitters at 3.2 THz and at temperatures up to 150 K. The effect of adding doping into the active quantum wells was studied in addition to reduced barrier widths from previous measurements. While the current through the sample is increased by the addition of doping, the emitted power is reduced through additional free carrier absorption and Coulombic scattering. Free electron laser measurements confirm the intersubband transitions in the quantum wells of the cascade devices and produce non-radiative lifetimes of 20 ps between 4 and 150 K. 相似文献
36.
Muthusamy Jayaraman Steven M. Ansell Barbara L. Mui Ying K. Tam Jianxin Chen Xinyao Du David Butler Laxman Eltepu Shigeo Matsuda Jayaprakash K. Narayanannair Kallanthottathil G. Rajeev Ismail M. Hafez Akin Akinc Martin A. Maier Mark A. Tracy Pieter R. Cullis Thomas D. Madden Muthiah Manoharan Michael J. Hope 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(34):8657-8661
37.
38.
Fry PW Itskevich IE Mowbray DJ Skolnick MS Finley JJ Barker JA O'Reilly EP Wilson LR Larkin IA Maksym PA Hopkinson M Al-Khafaji M David JP Cullis AG Hill G Clark JC 《Physical review letters》2000,84(4):733-736
New information on the electron-hole wave functions in InAs-GaAs self-assembled quantum dots is deduced from Stark effect spectroscopy. Most unexpectedly it is shown that the hole is localized towards the top of the dot, above the electron, an alignment that is inverted relative to the predictions of all recent calculations. We are able to obtain new information on the structure and composition of buried quantum dots from modeling of the data. We also demonstrate that the excited state transitions arise from lateral quantization and that tuning through the inhomogeneous distribution of dot energies can be achieved by variation of electric field. 相似文献
39.
40.
Rodenburg JM Hurst AC Cullis AG Dobson BR Pfeiffer F Bunk O David C Jefimovs K Johnson I 《Physical review letters》2007,98(3):034801
We demonstrate a hard-x-ray microscope that does not use a lens and is not limited to a small field of view or an object of finite size. The method does not suffer any of the physical constraints, convergence problems, or defocus ambiguities that often arise in conventional phase-retrieval diffractive imaging techniques. Calculation times are about a thousand times shorter than in current iterative algorithms. We need no a priori knowledge about the object, which can be a transmission function with both modulus and phase components. The technique has revolutionary implications for x-ray imaging of all classes of specimen. 相似文献