全文获取类型
收费全文 | 192篇 |
免费 | 2篇 |
专业分类
化学 | 96篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 12篇 |
物理学 | 82篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 11篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 10篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1957年 | 2篇 |
排序方式: 共有194条查询结果,搜索用时 15 毫秒
71.
M. Besnard O. Costerousse L. Merlin Y. Cohen 《Journal of Radioanalytical and Nuclear Chemistry》1975,26(1):201-208
The radiochemical purity of technetium-99m-tin-diethylene-triamino-pentaacetic acid (DTPA) complex is checked by ascending
paper chromatography. The percentage of uncomplexed technetium is lower than 5%. The technetium valency state is determined
by visible absorption spectrometry.
相似文献
72.
Alternating adsorption of polycations and polyanions on permeable supports provides a convenient and versatile method for preparing composite membranes with selective, ultrathin polyelectrolyte skins. Control over charge and composition in the polyelectrolyte skin allows highly selective separation of ions according to charge, size, or hydration energy. 相似文献
73.
Merlin Carl 《PAMM》2016,16(1):901-902
In the last two decades, various machine models of computability have been generalized to work in the transfinite. I will give an overview of these models, some of the main results concerning them and some reasons why studying them is of interest outside of foundational considerations. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
74.
Sean Merlin Edwin Rowold Ann Abegg Cathleen Berglund Jon Klover Nick Staten John P. McKearn Stephen C. Lee 《Applied biochemistry and biotechnology》1997,67(3):199-214
A deletion derivative of the cytokine human interleukin-3 (hIL-315–125, comprising amino acids 15–125 of the native protein) was produced as a fusion to the filamentous phage surface protein pIII.
The cytokine was detected in association with phage particles by protein immunoblotting. Compared to an equivalent quantity
of soluble cytokine, phage-presented hIL-315–125 exhibited reduced biological activity in a hIL-3-dependent cell proliferation assay. The reduction in activity was attributable
to presence of phage particles in the assay, rather than directly owing to physical incorporation of the cytokine into the
phage particle. Owing to the position of the amber codon in the phagemid vector, the phagemid-produced free hIL-315–125 species (designated hIL-315–125 ε) had 20 amino acids appended to its C-terminus; hIL-315–125 ε did not exhibit reduced bioactivity. hIL-315–125-presenting phage were affinity-selected with either a hIL-3-reactive polyclonal antibody or with cells expressing the heterodimeric
hIL-3 receptor. These data are consistent with the use of phage-display technology for the affinity selection of hIL-3 variants
with modified biological properties. 相似文献
75.
Jason T Miller John H Bartley Hereward JC Wimborne Aisha L Walker David C Hess William D Hill James E Carroll 《BMC neuroscience》2005,6(1):63
Background
Stromal cell-derived factor 1 (SDF-1 or CXCL12) is chemotaxic for CXCR4 expressing bone marrow-derived cells. It functions in brain embryonic development and in response to ischemic injury in helping guide neuroblast migration and vasculogenesis. In experimental adult stroke models SDF-1 is expressed perivascularly in the injured region up to 30 days after the injury, suggesting it could be a therapeutic target for tissue repair strategies. We hypothesized that SDF-1 would be expressed in similar temporal and spatial patterns following hypoxic-ischemic (HI) injury in neonatal brain. 相似文献76.
Bruening ML Dotzauer DM Jain P Ouyang L Baker GL 《Langmuir : the ACS journal of surfaces and colloids》2008,24(15):7663-7673
Over the last 15 years, the layer-by-layer deposition of polyelectrolytes and the growth of polymer brushes from surfaces have become established techniques for the formation of a wide range of thin films. This article discusses the use of these techniques in creating the skin layer of nanofiltration or gas-separation membranes and in functionalizing the interior of membranes for protein adsorption or catalysis. In the case of separation membranes for nanofiltration, the minimal thickness of layer-by-layer films allows for high flux, and the wide range of available polyelectrolytes that can form these films permits the tailoring of membranes for separations such as water softening, the reduction of F (-) concentrations, and the removal of dyes from wastewater. For gas separation, polymers grown from surfaces are more attractive than layer-by-layer coatings because most polyelectrolyte films are not highly gas-selective. Cross-linked poly(ethylene glycol dimethacrylate) films grown from porous alumina exhibit CO(2)/CH(4) selectivities of around 20, and the careful selection of monomers should further improve the selectivity of similar membranes. Both layer-by-layer methods and polymer brushes can also be employed to modify the interior of membranes, and we have utilized these techniques to create catalysts, antibody arrays in membranes, and membrane absorbers for protein purification. Polymer brushes are particularly attractive because they allow the absorption of multilayers of protein to yield membranes with binding capacities as high as 150 mg protein/cm(3). Some challenges in the practical implementation of these systems, such as the economical formation of membranes using highly permeable polymeric supports, and future directions in research on membrane modification with multilayer films and polymer brushes are also discussed herein. 相似文献
77.
Gustav Komlaga Grégory Genta-Jouve Sandrine Cojean Rita A. Dickson Merlin L.K. Mensah Philippe M. Loiseau Pierre Champy Mehdi A. Beniddir 《Tetrahedron letters》2017,58(38):3754-3756
The chemical investigation of the antimalarial plant Phyllanthus fraternus G. L. Webster (Phyllanthaceae) resulted in the discovery of the Securinega alkaloid (+)-allonorsecurinine (1), previously reported as a synthetic compound, together with the known ent-norsecurinine (2), nirurine (3), bubbialine (4), epibubbialine (5) and the lignan phyllanthin (6). The structure and absolute configuration of the new compound were elucidated on the basis of extensive spectroscopic analysis, optical rotation, and GIAO NMR shift calculation followed by CP3 analysis. The antiplasmodial activity of these compounds was evaluated against chloroquine-resistant (W2) and -sensitive (3D7) strains of Plasmodium falciparum. Among them, ent-norsecurinine (2) and (+)-allonorsecurinine (1) showed the strongest activity (IC50: 1.14 ± 0.32 and 2.57 ± 0.53 µM) respectively, against W2 but one of the weakest against 3D7. 相似文献
78.
In a recent paper published in MSS, Wilson and Pritchard (2007) exhibit some results suggesting that the limiting probability of the referendum paradox given in Feix et al. (2004) could be wrong. After having explained the origin of this disagreement, we propose in this note some further analytical (and complementary) methods to compute the probability of this paradox. 相似文献
79.
OK Yoon WG Hwang JC Choe MS Kim 《Rapid communications in mass spectrometry : RCM》1999,13(14):1515-1521
A technique to investigate photodissociation kinetics on a nanosecond time scale has been devised for molecular ions generated by multiphoton ionization (MPI) using mass-analyzed ion kinetic energy spectrometry. The branching ratio or rate constant has been determined for the photodissociation of the n-butylbenzene, bromobenzene, iodobenzene, and aniline molecular ions generated by MPI at 266 nm. The ion internal energies have been estimated by comparing the measured kinetic data with the previous energy dependence data. The analysis has shown that only those molecular ions generated by two-photon ionization contribute to the photodissociation signals. Around half of the available energy has been found to remain as molecular ion internal energy in the two-photon ionization process. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
80.
α-Haloketones and -dibromides are converted to the corresponding ketones and alkenes respectively with nickel boride generated from sodium borohydride and nickel chloride. 相似文献