全文获取类型
收费全文 | 218篇 |
免费 | 10篇 |
专业分类
化学 | 159篇 |
晶体学 | 1篇 |
力学 | 10篇 |
数学 | 20篇 |
物理学 | 38篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 12篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 26篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 13篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有228条查询结果,搜索用时 15 毫秒
51.
52.
Loukas Athanasekos Alexandros El Sachat Stergios Pispas Christos Riziotis 《Journal of Polymer Science.Polymer Physics》2014,52(1):46-54
Efficient functionalization of polymer optical fibers' (POF) surface by a novel block copolymer material toward the development of low‐cost multiagent sensors is presented. The employed poly(styrene sulfonate‐b‐tert‐butylstyrene) (SPS‐b‐PtBS) diblock copolymer possesses two blocks of distinctively different polarity and charge, the hydrophilic SPS which is sensitive to polar substances and the hydrophobic PtBS which is sensitive to organic solvents. The coexistence of two different blocks allows for the detection of a wide variety of agents, ranging from ammonia, and organic solvents, to biomolecules like lysozyme, at room temperature as opposed to alternative usually more complicated techniques, all with the sole use of one sensing medium. Copolymers' high glass transition temperature enables the formation of stable and environmentally robust overlayers. The sensing performance of the material is evaluated experimentally on the customizable platform of POFs, demonstrating fast response, high operational reversibility, and also reusability in successively different testing agents. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 46–54 相似文献
53.
Alexandros Pitilakis Odysseas Tsilipakos Emmanouil E. Kriezis 《Applied Physics A: Materials Science & Processing》2014,115(2):475-479
Hybrid silicon-plasmonic waveguides constitute an appealing platform for integrated photonic circuitry. They merge the technical maturity and prevalence of the SOI platform with the subwavelength confinement of plasmonic waveguides, essential for accessing enhanced nonlinear response at micron length-scales. Employing full-wave numerical simulations complemented with Schrödinger equation techniques, we propose nonlinear waveguide designs for Kerr-effect applications exhibiting minimized impairments due to free-carrier effects, thus raising the power-ceiling imposed on standard silicon waveguides. 相似文献
54.
55.
Demetris P. Papahatjis Dr. Victoria R. Nahmias Spyros P. Nikas Dr. Marion Schimpgen Alexandros Makriyannis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(13):4091-4099
Two novel methyl‐substituted arachidonic acid derivatives were prepared in an enantioselective manner from commercially available chiral building blocks, and were found to be excellent templates for the development of (13S)‐methyl‐substituted anandamide analogues. One of the compounds synthesized, namely, (13S,5Z,8Z,11Z,14Z)‐13‐methyl‐eicosa‐5,8,11,14‐tetraenoic acid N‐(2‐hydroxyethyl)amide, is an endocannabinoid analogue with remarkably high affinity for the CB1 cannabinoid receptor. 相似文献
56.
57.
Bächler J Bartke J Bialkowska H Bock R Brockmann R Buncic P Chase SI Derado I Eckardt V Eschke J Ferenc D Fleischmann B Foka P Fuchs M Gazdzicki M Gladysz E Harris JW Heck W Hoffmann M Jacobs PM Kabana S Kadija K Keidel R Kosiec J Kowalski M Kühmichel A Lahanas M Lee JY Ljubicic A Margetis S Morse R Nappi E Odyniec G Paic G Panagiotu AD Petridis A Piper A Posa F Poskanzer AM Pugh HG Pühlhofer F Rai G Rauch W Renfordt R Röhrich D Roland G Rothard H Runge K Sandoval A Schambach JJ Schmitz N 《Physical review letters》1994,72(10):1419-1422
58.
The molecular and electronic structures, stabilities, bonding features, and magnetoresponsive properties of three‐membered [c‐Ln3]+/0/? (Ln = La, Ce, Pr, Nd, Gd, Lu) and heterocyclic six‐membered [c‐Ln3E3]q (Ln = La, Ce, Pr, Nd, Gd, Lu; E = C, N; q = 0 or 1) rings have been investigated by means of electronic structure calculation methods at the DFT level. The [c‐Ln3]+/0/? clusters are predicted to be bound with respect to dissociation to their constituent atoms, the estimated binding energies ranging from 45.8 to 2056.4 kJ/mol. The [c‐Ln3] rings capture easily a planar three‐coordinated nitrogen atom at the center or above the center of the ring yielding the lanthanide nitride clusters [c‐Ln3(μ3‐N)] adopting a planar geometry, except [c‐La3(μ3‐N)] which exhibits pyramidal geometry. The [c‐Ln3(μ3‐N)] clusters are predicted to be bound, with respect to dissociation to N (4S) atom and [c‐Ln3] clusters in their ground states, the binding energies ranging from 53.9 to 257.9 kcal/mol. The six‐membered [c‐Ln3E3]q rings are predicted to be bound with respect to dissociation to LnEq monomers in their ground states with dissociation energies in the range of 173.8 to 318.0 kcal/mol. Calculation of the NICSzz‐scan curves of the clusters predicted a “hermaphrodic” magnetic response of the [c‐Ln3]+/0/? and heterocyclic six‐membered [c‐Ln3E3]q rings, manifested by the coexistence of successive diatropic (aromatic) and paratropic (antiaromatic) zones. The [c‐La3]+/0/? and [c‐Lu3]? are predicted to be weakly antiaromatic, the [c‐Lu3]0/+, [c‐Lu3C3]+, and [c‐Lu3N3] double (σ+π) aromatic, and the [c‐Gd3C3] and [c‐Gd3N3]+ rings (σ+δ)‐aromatic systems. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011 相似文献
59.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. 相似文献
60.
Miltiadis Vasileiadis Ioannis Koutselas Stergios Pispas Nikolaos A. Vainos 《Journal of Polymer Science.Polymer Physics》2016,54(5):552-560
A systematic approach and a new scheme for the evaluation of the as–is encapsulation of CdSe/ZnS core/shell quantum dots into polymer matrices is proposed, aiming to the implementation of thin film photonic integrated structures. Work focuses on quantum dots capped by hexadecylamine and trioctylphosphine oxide with no ligand exchange or other intermediate processing steps involved. The polymers studied include poly(methyl–methacrylate) (PMMA), polystyrene and acrylic polymers incorporating long alkyl chains, which are expected to promote the compatibility of the quantum dot ligands to that of the polymer chains. In this approach, the variation of photoluminescence properties of the nanocomposite thin films is measured versus increased concentration of the quantum dots, so as to evaluate the suitability of each polymer structure as an efficient host. Furthermore, the refractive index of the quantum dots/polymer nanocomposite thin films are also estimated using white light reflectance spectroscopy data, as appropriate for the integration of photonic devices. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 552–560 相似文献