全文获取类型
收费全文 | 92篇 |
免费 | 1篇 |
专业分类
化学 | 58篇 |
晶体学 | 3篇 |
数学 | 2篇 |
物理学 | 30篇 |
出版年
2024年 | 1篇 |
2022年 | 7篇 |
2020年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 12篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 15 毫秒
41.
A combination of pyridinium dichromate/tert-butyl hydroperoxide (1:1) has been found to be an excellent reagent for the highly selective regeneration of ketones from ketoximes. 相似文献
42.
Gunanathan C Gnanaprakasam B Iron MA Shimon LJ Milstein D 《Journal of the American Chemical Society》2010,132(42):14763-14765
The acridine-based pincer complex 1 exhibits an unprecedented mode of metal-ligand cooperation involving a "long-range" interaction between the distal acridine C9 position and the metal center. Reaction of 1 with H(2)/KOH results in H(2) splitting between the Ru center and C9 with concomitant dearomatization of the acridine moiety. DFT calculations show that this process involves the formation of a Ru dihydride intermediate bearing a bent acridine ligand in which C9 is in close proximity to a hydride ligand followed by through-space hydride transfer. Ammonia induces transfer of a hydride from the Ru center of 1 to C9 of the flexible acridine pincer ligand, forming an unusual dearomatized fac-acridine PNP complex. 相似文献
43.
Subramani Selvi Arun Kannan John M. Jayaraj Thangavel Selvi Muthusamy Karthikeyan Chidambaram Prahalathan Natarajan Sampath Kannupal Srinivasan 《Journal of heterocyclic chemistry》2024,61(4):669-679
A series of 3-hydroxypyrazole derivatives have been synthesized by a base-promoted reaction of nitro-substituted donor–acceptor cyclopropanes with hydrazines. The synthesized compounds have been investigated for their ability to inhibit aquaporin 9 (AQP9) in rat Leydig cells (LC-540). The protein data bank structure for AQP9 was predicted using homology modeling; and the protein–ligand interaction for the synthesized hydroxyl pyrazole derivatives were analyzed using molecular modeling and docking studies. The results of in silico analyses showed that compound 5b had a higher binding affinity with AQP9 than other compounds. Further, in vitro studies conducted in LC-540 cells confirmed that compound 5b effectively inhibits AQP9. Hence, compound 5b may be used as an inhibitor in enhancing our understanding of AQP9 function, and in the treatment of several diseases. 相似文献
44.
Hole mobility and remote scattering in strained InGaSb quantum well MOSFET channels with Al2O3 oxide
Shailesh Kumar Madisetti Thenappan Chidambaram Padmaja Nagaiah Vadim Tokranov Michael Yakimov Serge Oktyabrsky 《固体物理学:研究快报》2013,7(8):550-553
Hall mobility and major scattering mechanisms in surface and buried MBE grown strained InGaSb quantum well (QW) MOSFET channels with in‐situ grown Al2O3 gate oxide are analyzed as a function of sheet hole density, top‐barrier thickness and temperature. Mobility dependence on Al0.8Ga0.2Sb top‐barrier thickness shows that the relative contribution of interface‐related scattering is as low as ~30% in the surface QW channel. An InAs top capping layer reduces the interface scattering even further; the sample with 3 nm total top‐barrier thickness demonstrates mobility of 980 cm2/Vs giving sheet resistance of 4.3 kΩ/sq, very close to the minimum QW resistance in the bulk. The mobility–temperature dependences indicate that the interface‐related scattering is dominated by remote Coulomb scattering at hole densities <1 × 1012 cm–2. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
45.
The results of electrical resistance (R), thermoelectric power (TEP) and X-ray diffraction measurements on praseodymium (Pr) and its alloys with thorium under pressure
are reported. The maximum inR vsP curve exhibited by Pr persists only in the dhcp phase of PrTh alloy. X-ray measurements confirmed that in the alloys also
the maximum inR vsP curve is due to the dhcp → fcc transition. Thus the behaviour of Pr and Pr-Th alloys is different from that of La and its
alloys with Ce and Th where the maximum in theR vsP curve is electronic in origin and is exhibited by the dhcp, fcc and dist fcc phases. 相似文献
46.
A Sequeira S N Momin H Rajagopal J N Soni R Chidambaram Dilip Kumar A Ramana Rao V M Gopu 《Pramana》1978,10(3):289-302
The design and fabrication of an indigenous on-line computer controlled four-circle neutron diffractometer at the CIRUS reactor
in Trombay are described. The diffractometer has an 18 in dia full-circle crystal-orienter which is sturdy enough to carry
a cryostat. Three crystal orientation angles χ, φ and ω and the detector angle 2θ can be set to an accuracy of 0·01°. The
four angle shafts are driven through precision worm-gears by SCR-controlled DC motors and their instantaneous positions sensed
by optical digitizers. The diffractometer is interfaced to an ECIL TDC-312 computer system consisting of the CPU with 4K-memory,
ASR-35 teletype, X-Y plotter and the digital input/output system (DIOS). The DIOS which operates under program control is
a real-time peripheral device used to exchange information in digital form between the computer and the diffractometer. A
software package consisting of over 40 useroriented teletype commands has been developed for on-line control and automatic
data-acquisition. 相似文献
47.
Clusters of 2x10(3) to 4x10(4) Ar atoms are Coulomb exploded in intense (up to 8x10(15) W cm(-2)) laser fields. The dependence of multiply charged argon ion energies on the polarization state of light is probed. A directional asymmetry in the ion-explosion energies is observed for the highest charge states. The ion-energy distribution consists of a low-energy isotropic component, and a high-energy anisotropic one. The results are discussed in terms of an asymmetric Coulomb-explosion scenario. 相似文献
48.
Viftrup SS Kumarappan V Trippel S Stapelfeldt H Hamilton E Seideman T 《Physical review letters》2007,99(14):143602
We illustrate, experimentally and theoretically, a laser-based method to control the rotations of polyatomic molecules in 3D space. A linearly polarized nanosecond pulse strongly aligns the most polarizable axis of an asymmetric top molecule along its polarization axis while an orthogonally polarized, femtosecond pulse sets the molecules into controlled rotation about the aligned axis. As a result, strong three-dimensional (3D) alignment occurs shortly after the femtosecond pulse and is repeated periodically, reflecting coherent revolution about the molecular axis. Our method opens new directions for research in orientationally confined complex molecules. 相似文献
49.
50.
Abstract The structural energy differences have been calculated for zirconium as a function of pressure at zero temperature using the Andersen force theorem and the linear muffin tin orbital method. The structures included are the following: α (hcp), the room temperature room pressure phase, ω- a three atom simple hexagonal, bcc and fcc. Our calculations show that the bcc structure would become energetically most favourable above 11 GPa. This results is in agreement with well known correlation between the crystal structure and the d-electron population in transition metals at normal volume. The diamond anvil cell based high pressure x-ray diffraction experiments are in progress to verify this result. 相似文献