全文获取类型
收费全文 | 955篇 |
免费 | 11篇 |
国内免费 | 16篇 |
专业分类
化学 | 559篇 |
晶体学 | 18篇 |
力学 | 18篇 |
综合类 | 1篇 |
数学 | 1篇 |
物理学 | 385篇 |
出版年
2024年 | 5篇 |
2023年 | 111篇 |
2021年 | 3篇 |
2020年 | 17篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 18篇 |
2015年 | 22篇 |
2014年 | 27篇 |
2013年 | 52篇 |
2012年 | 14篇 |
2011年 | 32篇 |
2010年 | 32篇 |
2009年 | 72篇 |
2008年 | 68篇 |
2007年 | 58篇 |
2006年 | 55篇 |
2005年 | 31篇 |
2004年 | 25篇 |
2003年 | 24篇 |
2002年 | 33篇 |
2001年 | 28篇 |
2000年 | 34篇 |
1999年 | 36篇 |
1998年 | 35篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 7篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有982条查询结果,搜索用时 15 毫秒
921.
Abstract A simple method for the surface grafting of crosslinked polystyrene latex particles of narrow size distribution as core is described. Amino groups were generated on the surface of these microspheres by a two-step process of nitration and subsequent reduction. Polyethylene glycol chain of desired molecular weight was covalently linked to the surface amino group using diiso-cyanate-coupling reaction. The method is appropriate for designing brush polymers. 相似文献
922.
923.
Mausumi Chattopadhyaya Sabyasachi Sen Md.Mehboob Alam Swapan Chakrabarti 《Journal of Physics and Chemistry of Solids》2014
The present study deals with the relative performance of the various density functional approaches in evaluating the band gap of polymer materials. Several density functional approximations that includes pure generalized gradient approximated (GGA) functional, meta-GGA, hybrid and range separated hybrid functionals have been used to evaluate the electrical band gap or transport gap of the studied polymers and compared with that obtained using Hubbard U corrected GGA functional (GGA+U). It has been observed that the experimental band gap of the polymers studied is satisfactorily reproducible when GGA+U approach is adopted. The band gap analyses further suggest that range separated hybrid functional, CAM-B3LYP, largely overestimates the band gap of all the polymers studied while the performance of hybrid B3LYP functional and other range separated hybrid functional like HSE is moderate. Better performance of the GGA+U method clearly indicates that short range coulomb correlation plays more significant role over the non-local Hartree-Fock (HF) exchange in determining the electrical band gap of polymer materials. It is also noticeable that the Hubbard U parameter used for the various polymers under consideration is relatively large, indicating the semi-empirical nature of the GGA+U level of calculations. The present finding will help us design new low band gap polymer through estimating band gap by the GGA+U method and this could be very useful for solar cell research. 相似文献
924.
Optically stimulated luminescence (OSL) is a known phenomenon with several applications in various fields of radiation dosimetry. This phenomenon may be used for estimating dose of absorbed radiation as well as the age of archeological and geological samples. For some applications (e.g. in medicine) it would be develop detectors in the form of high-area flexible foils. This could be achieved by incorporating small grains of typical inorganic crystalline OSL phosphors into organic (polymer) matrix. In the present study we prepared samples containing Al2O3:C microcrystalline grains in polymeric matrices. Polymer matrices change the OSL readout and significantly influence the total OSL response. We observed that the dose responses of investigated hybrid materials are linear in the studied range and depend on the types of the matrix and radiation. 相似文献
925.
The properties of coordination complexes grafted to a polymer backbone are reviewed in this article. The focus is on complexes of phthalocyanine and tetraazaannulene (5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine, also abbreviated tmdbztaa) with various transition metal ions and Al(III). In addition to the morphological characteristics of the materials, their thermal and photochemical reactions are reviewed. Processes such as catalysis of the lignin degrading process and the reduction of CO2 are presented as examples of these materials potential applications. 相似文献
926.
Vijay Kumar Thakur Manju Kumari Thakur Raju Kumar Gupta 《International Journal of Polymer Analysis and Characterization》2014,19(3):256-271
The effective utilization of raw natural fibers as indispensable component in polymers for developing novel low-cost eco-friendly composites with properties such as acceptable specific strength, low density, high toughness, good thermal properties, and biodegradability is one of the most rapidly emerging fields of research in polymer engineering and science. In fact, raw natural fiber–reinforced composites are the subject of numerous scientific and research projects, as well as many commercial programs. Keeping in mind the immense advantages of raw natural fibers, in the present article we concisely review raw natural fiber/polymer matrix composites with particular focus on their mechanical properties. 相似文献
927.
Josef Janča Jaroslav Sobota 《International Journal of Polymer Analysis and Characterization》2014,19(4):296-308
More than 45 years have passed since the invention of field-flow fractionation (FFF). During this time, several methods and techniques, differing mainly by the nature of the applied field, have been proposed and experimentally implemented. However, only few of them are currently in practical laboratory use. Recent trends of miniaturization of all separation techniques have also been followed in the development of FFF apparatus. The aim of this work is to give an overview of the advances that are important in the practical use of microfluidic FFF techniques. Another aim is a critical evaluation of the crucial characteristics of the most widespread FFF techniques performed in standard-size channels. 相似文献
928.
The analysis of synthetic polymers represents today an important part of polymer science to determine their physical properties and to optimize the performance of polymeric materials for block copolymers as well as blend systems. The characterization can easily and rapidly be performed by mass spectrometry. In particular, the film formation of a synthetic polymer is of interest in material research and quality control, which can be determined by employing mass spectrometric imaging (MSI) using secondary ion mass spectrometry (SIMS) or matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. MALDI-MSI has been rapidly improved for the analysis of tissue cross-sections due to its soft ionization and accessible m/z range, which both also play an important role in polymer science. On the other hand, SIMS-MSI enables a sub-micrometer molecular spatial resolution, which is limited in MALDI-MSI due to the spatial resolution capabilities of the laser desorption process. The aim of the present contribution is to summarize recent advances in both imaging techniques for the analysis of synthetic polymers and to highlight their capabilities to correlate several imaging modalities in future applications. 相似文献
929.
Sijia Cao Prof. Dr. Arne Thomas Dr. Changxia Li 《Angewandte Chemie (International ed. in English)》2023,62(8):e202214391
Solar-driven water purification is considered as an effective and sustainable technology for water treatment using green solar energy. One major goal for practical applications is to improve the solar evaporation performance by the design of novel photothermal materials, with optimized heat localization and water transport pathways to achieve reduced energy consumption for water vaporization. Recently, some emerging materials like polymers, metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and also single molecules were employed to construct novel solar evaporation systems. In this minireview, we present an overview of the recent efforts on materials development for water purification systems. The state-of-the-art applications of these emerging materials for solar-driven water treatment, including desalination, wastewater purification, sterilization and energy production, are also summarized. 相似文献
930.
Benjamin P. M. Lake Dr. Ryan G. Wylie Dr. Cyril Bařinka Dr. Anthony F. Rullo 《Angewandte Chemie (International ed. in English)》2023,62(9):e202214659
Chemical immunotherapeutic strategies including Antibody Recruiting Molecules (ARMs - bivalent small molecules containing an antibody-binding domain (ABD) and a target-binding domain (TBD)) direct immune-mediated clearance of diseased cells. Anti-cancer ARM function relies on high tumor antigen valency, limiting function against lower antigen expressing tumors. To address this limitation, we report a tunable multivalent immune recruitment (MIR) platform to amplify/stabilize antibody recruitment to cells with lower antigen valencies. An initial set of polymeric ARMs (pARMs) were synthesized and screened to evaluate ABD/TBD copy number, ratio, and steric occlusion on specific immune induction. Most pARMs demonstrated simultaneous high avidity binding to anti-dinitrophenyl antibodies and prostate-specific membrane antigens on prostate cancer. Optimized pARMs mediated enhanced anti-cancer immune function against lower antigen expressing target cells compared to an analogous ARM. 相似文献