全文获取类型
收费全文 | 4863篇 |
免费 | 1015篇 |
国内免费 | 200篇 |
专业分类
化学 | 5209篇 |
晶体学 | 18篇 |
力学 | 55篇 |
综合类 | 16篇 |
数学 | 190篇 |
物理学 | 590篇 |
出版年
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 31篇 |
2019年 | 99篇 |
2018年 | 76篇 |
2017年 | 139篇 |
2016年 | 172篇 |
2015年 | 451篇 |
2014年 | 478篇 |
2013年 | 491篇 |
2012年 | 451篇 |
2011年 | 480篇 |
2010年 | 431篇 |
2009年 | 409篇 |
2008年 | 413篇 |
2007年 | 349篇 |
2006年 | 295篇 |
2005年 | 290篇 |
2004年 | 277篇 |
2003年 | 243篇 |
2002年 | 127篇 |
2001年 | 92篇 |
2000年 | 89篇 |
1999年 | 59篇 |
1998年 | 29篇 |
1997年 | 23篇 |
1996年 | 22篇 |
1995年 | 7篇 |
1994年 | 12篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有6078条查询结果,搜索用时 15 毫秒
271.
Pol Besenius 《Journal of polymer science. Part A, Polymer chemistry》2017,55(1):34-78
The self‐assembly into supramolecular polymers is a process driven by reversible non‐covalent interactions between monomers, and gives access to materials applications incorporating mechanical, biological, optical or electronic functionalities. Compared to the achievements in precision polymer synthesis via living and controlled covalent polymerization processes, supramolecular chemists have only just learned how to developed strategies that allow similar control over polymer length, (co)monomer sequence and morphology (random, alternating or blocked ordering). This highlight article discusses the unique opportunities that arise when coassembling multicomponent supramolecular polymers, and focusses on four strategies in order to control the polymer architecture, size, stability and its stimuli‐responsive properties: (1) end‐capping of supramolecular polymers, (2) biomimetic templated polymerization, (3) controlled selectivity and reactivity in supramolecular copolymerization, and (4) living supramolecular polymerization. In contrast to the traditional focus on equilibrium systems, our emphasis is also on the manipulation of self‐assembly kinetics of synthetic supramolecular systems. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 34–78 相似文献
272.
273.
Biologically inspired optimal structures combining the bioresorbable and bioactive properties are expected for the next generation of biomaterials. A compositional gradient structure was found to be spontaneously formed in the film of biodegradable chitosan/poly(vinyl alcohol) blend by casting aqueous solution on an aluminum dish. The formation of compositional gradient structure was confirmed by FTIR mapping measurement, DMTA measurement, and SEM observation on the freeze‐fractured cross section. In DMTA measurement, a broadening of the α‐relaxation curve corresponding to the glass transition was observed for the compositional gradient film, while a composition‐dependent single glass transition was observed for the homogeneous blend films. The resulted film with stable self‐organized compositional gradient exhibits novel physical properties inaccessible for the film of homogeneous blends obtained by casting from the same solution on a Teflon dish. The compositional gradient films present a unique combination of stronger stress and higher yield strain when compared with those of the homogeneous films at both dry and wet states. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3069–3076, 2005 相似文献
274.
275.
Masashi Watanabe 《先进技术聚合物》2005,16(10):744-748
In this article the possibility of using various elastic polymer substrates for preparing wrinkled gold films was studied. The gold film was deposited on the substrate using an ion‐sputtering technique, while the substrate was stretched and fixed on a frame. The obtained gold film had wrinkles with a striped pattern. However, whether the pattern was well regulated or not depended on the substrate material. Polydimethylsiloxane (PDMS) was the preferable material when it did not contain fillers. Materials containing fillers are not suitable for this purpose. However, double layer substrates that consist of the PDMS without fillers (the upper layer) and the material containing fillers (the lower layer) could be used to obtain a relatively well‐ordered pattern. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
276.
Back Cover: Multifunctional Tricarbazolo Triazolophane Macrocycles: One‐Pot Preparation,Anion Binding,and Hierarchical Self‐Organization of Multilayers (Chem. Eur. J. 2/2016)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
277.
《Macromolecular bioscience》2018,18(7)
Herein, a new series of non‐ionic dendritic and carbohydrate based amphiphiles is synthesized employing biocompatible starting materials and studied for supramolecular aggregate formation in aqueous solution. The dendritic amphiphiles 12 and 13 possessing poly(glycerol) [G2.0] as hydrophilic unit and C‐10 and C‐18 hydrophobic alkyl chains, respectively, exhibit low critical aggregation concentration (CAC) in the order of 10−5m and hydrodynamic diameters in the 8–10 nm range and supplemented by cryogenic transmission electron microscopy. Ultraviolet‐visible (UV‐Vis) and fluorescence spectroscopy suggests the effective solubilization of hydrophobic guests by the self‐assembled architectures, with the nanotransporters 12 and 13 possessing the highest encapsulation efficiency of 80.74 and 98.03% for curcumin. Efficient uptake of encapsulated curcumin in adenocarcinomic human alveolar basal epithelial (A549) cells is observed by confocal laser scanning microscopy. Amphiphiles 12 and 13 are non‐cytotoxic at the concentrations studied, however, curcumin encapsulated samples efficiently reduce the viability of A549 cells in vitro. Experimental studies indicate the ability of amphiphile 13 to encapsulate 1‐anilinonaphthalene‐8‐sulfonic acid (ANS) and curcumin with binding constant of 1.16 × 1055m −1 and 1.43 × 106m −1, respectively. Overall, our findings demonstrate the potential of these dendritic amphiphiles for the development of prospective nanocarriers for the solubilization of hydrophobic drugs. 相似文献
278.
Christian Rein Steen Nissen Mariusz Grzelakowski Morten Meldal 《Journal of polymer science. Part A, Polymer chemistry》2016,54(13):2032-2039
A facile click chemistry method of immobilizing surface‐functionalized polymer vesicles on casted polymeric PAN substrates is described. Microporous PAN membranes were subjected to hydrochloric acid hydrolysis to obtain surface carboxylates. The carboxylic groups were activated with EDC/NHS‐solution and were then reacted with propargylamine to introduce alkyne groups for CuAAC reactions. The alkyne functionality of the modified membrane surface was verified by reaction with an azide functional click dye both before and after the immobilization of azide‐functionalized ABA vesicles. The efficient postfunctionalization of the membrane with alkyne allowed quantitative coverage of the membrane surface with a polymersome monolayer, as confirmed by immobilization of polymerzomes loaded with a fluorescent dye. Polymersome monolayers immobilized on alkyne functionalized PAN‐membranes were characterized by cryo‐SEM and monolayers were confirmed by atom force microscopy. These methods opens up new avenues for preparing membrane based filtration and sensor technologies. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2032–2039 相似文献
279.
280.
Dr. Gui‐Chao Kuang Ming‐Jun Teng Prof. Xin‐Ru Jia Prof. Dr. Er‐Qiang Chen Prof. Dr. Yen Wei 《化学:亚洲杂志》2011,6(5):1163-1170
There is a delicate balance for a low‐weight molecule to behave as a gelator or crystal. The synthesis of two novel amino acid‐based naphthalene‐dendrons, Nap ‐ G1 and Nap ‐ G2 is described. Both dendrons display polymorphic properties in organic solvents. Nap ‐ G1 developed a fibrous network with β‐sheet architecture in cyclohexane but exhibited a spherulitic network in mixed solvents (chloroform/petroleum ether 1:5, v/v). On the other hand, Nap ‐ G2 acted as an efficient organogelator in chloroform but formed crystalline fibers in relatively high polarity solvents (such as acetone and methanol). Combinations of characterizations have been employed to study the polymorphism. 相似文献