全文获取类型
收费全文 | 117篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 68篇 |
力学 | 5篇 |
数学 | 14篇 |
物理学 | 35篇 |
出版年
2023年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1936年 | 1篇 |
1925年 | 1篇 |
1906年 | 2篇 |
1904年 | 1篇 |
1897年 | 2篇 |
1882年 | 1篇 |
1879年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 15 毫秒
11.
12.
13.
Ohne Zusammenfassung 相似文献
14.
Jesús Martínez-Sánchez Rufina Bastida Alejandro Macías Harry Adams David E. Fenton Paulo Pérez-Lourido Laura Valencia 《Polyhedron》2010
Acetate and perchlorate dinuclear metal complexes of Co(II), Cu(II) and Zn(II) with the cresolate polypodal ligand having mixed phenolate and pyridyl pendant functionalities, H3L, have been synthesized. The complexes were characterized by microanalysis, LSI mass spectrometry, IR, UV–Vis spectroscopy, magnetic studies and conductivity measurements. Crystal structures of H3L, [Cu2(HL)(OAc)(H2O)2](OAc)·1.5H2O and [Zn2L(CH3OH)3](ClO4)CH3OH·2H2O complexes, have been also determined. 相似文献
15.
J. N. Spencer Travis F. Ganunis Abrahim I. Zafar Shaym Puppala James L. Ealy Larry J. Fenton Sunita Gupta C. H. Yoder J. E. Mihalick 《Journal of solution chemistry》1992,21(9):1005-1012
Equilibrium constants and enthalpies of hydrogen-bond formation of mcresol to various cyclic (crown) and acyclic polyethers have been determined in benzene solvent. Equilibrium constants indicated no evidence for an operative macrocyclic effect; the relationship between the increasing size of the equilibrium constant and the number of ether oxygens was rationalized with a simple statistical thermodynamic model. Enthalpies of interactions ranged between –19 and –23 kJ-mol–1. In agreement with PCILO calculations, enthalpies of interaction were essentially independent of the number of oxygen atoms in the ether; no significant difference in enthalpies of interaction between cyclic and acyclic ethers was found. 相似文献
16.
17.
There is currently a renewed focus aimed at understanding allosteric mechanisms at atomic resolution. This current interest
seeks to understand how both changes in protein conformations and changes in protein dynamics contribute to relaying an allosteric
signal between two ligand binding sites on a protein (e.g., active and allosteric sites). Both nuclear magnetic resonance
(NMR), by monitoring protein dynamics directly, and hydrogen/deuterium exchange, by monitoring solvent accessibility of backbone
amides, offer insights into protein dynamics. Unfortunately, many allosteric proteins exceed the size limitations of standard
NMR techniques. Although hydrogen/deuterium exchange as detected by mass spectrometry (H/DX-MS) offers an alternative evaluation
method, any application of hydrogen/deuterium exchange requires that the property being measured functions in both H2O and D2O. Due to the promising future H/DX-MS has in the evaluation of allosteric mechanisms in large proteins, we demonstrate an
evaluation of allosteric regulation in D2O. Exemplified using phenylalanine inhibition of rabbit muscle pyruvate kinase, we find that binding of the inhibitor is greatly
reduced in D2O, but the effector continues to elicit an allosteric response. 相似文献
18.
E.W. Fenton 《Solid State Communications》1981,38(6):457-461
It is shown that certain conditions on the anomalous quasiaverages of electron-hole pairing are satisfied by all eigenstates of the hamiltonian. These conditions are imposed on approximate states with electron-hole pairing such as those in the Hartree-Fock theory of Halperin and Rice. In Hartree-Fock theory at least, no current-density-wave excitonic states exist. 相似文献
19.
The upper critical field is determined for an even-parity singlet pairing state in the presence of arbitrary spin-orbit scattering. Comparison with critical field experiments suggests that superconductivity in CeCu2Si2 is a singlet pairing state, and in UBe13 is either a triplet pairing state or is a singlet state with restrictive conditions that the pair orbital be nearly isotropic and that strong spin-orbit scattering increase strongly as the field increases. 相似文献
20.
This paper describes the use of a mixed-integer programming model for the problem of determining methods of reinforcing and increasing a natural gas pipeline network. The model considers the options of (i) reinforcing pipes, (ii) building new pipes into the network, (iii) setting up of liquid natural gas tanks at certain points on the network, and attempts to find the best policy for satisfying demand levels. Because of the difficulties of solving the resultant mixed-integer problem, the model can only be used for small networks. 相似文献