全文获取类型
收费全文 | 313篇 |
免费 | 13篇 |
国内免费 | 4篇 |
专业分类
化学 | 259篇 |
晶体学 | 8篇 |
力学 | 8篇 |
数学 | 42篇 |
物理学 | 13篇 |
出版年
2024年 | 3篇 |
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 18篇 |
2015年 | 10篇 |
2014年 | 4篇 |
2013年 | 35篇 |
2012年 | 9篇 |
2011年 | 18篇 |
2010年 | 16篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有330条查询结果,搜索用时 15 毫秒
71.
Effect of thiol-containing monomer on the preparation of temperature-sensitive hydrogel microspheres
Françoise Meunier Christian Pichot Abdelhamid Elaïssari 《Colloid and polymer science》2006,284(11):1287-1292
The main objective of this study is to prepare, thermally, sensitive microgel particles bearing thiol groups via precipitation polymerization of N-isopropylacrylamide (NIPAM), methylenebisacrylamide (MBA) and vinylbenzylisothiouronium chloride (VBIC) using 2-2′-azobis(2-amidinopropane)-dihydrochloride (V50) as initiator. The influence of various parameters has been investigated as a systematic study to point out the role of each reactant on polymerization conversion, and consequently, on particles and water-soluble polymer formation. The final microgel particles were characterized with respect to particle size and swelling ability. The aim of this paper is to complete our first short communication; Macromolecular symposia, 2000. 150: p. 283–290. 相似文献
72.
Abdelhamid Elaissari 《Macromolecular Symposia》2005,229(1):47-55
Summary: This short review aimed to give to the reader brief applications of polymer colloids in biomedical area and principally in medical diagnostics. Colloidal polymer particles are mainly used as solid supports, as label for biomolecules reactions detection, and as a carrier. The elaboration of appropriate colloids is reached via numerous processes such as polymerization in dispersed media (dispersion, emulsion, precipitation, miniemulsion polymerizations) or as physico-chemical methodologies (i.e., self-assembly). After a short introduction, some particles elaborations are presented and their applications are briefly described and illustrated. 相似文献
73.
Abdulmalik S. Altamimi Adel S. El-Azab Sami G. Abdelhamid Mubarak A. Alamri Ashraf H. Bayoumi Safar M. Alqahtani Alhumaidi B. Alabbas Ali I. Altharawi Manal A. Alossaimi Menshawy A. Mohamed 《Molecules (Basel, Switzerland)》2021,26(10)
A new series of 8-methoxy-2-trimethoxyphenyl-3-substituted quinazoline-4(3)-one compounds were designed, synthesized, and screened for antitumor activity against three cell lines, namely, Hela, A549, and MDA compared to docetaxel as reference drug. The molecular docking was performed using Autodock Vina program and 20 ns molecular dynamics (MD) simulation was performed using GROMACS 2018.1 software. Compound 6 was the most potent antitumor of the new synthesized compounds and was evaluated as a VEGFR2 and EGFR inhibitor with (IC50, 98.1 and 106 nM respectively) compared to docetaxel (IC50, 89.3 and 56.1 nM respectively). Compounds 2, 6, 10, and 8 showed strong cytotoxic activities against the Hela cell line with IC50 of, 2.13, 2.8, 3.98, and 4.94 µM, respectively, relative to docetaxel (IC50, 9.65 µM). Compound 11 showed strong cytotoxic activity against A549 cell line (IC50, 4.03 µM) relative to docetaxel (IC50, 10.8 µM). Whereas compounds 6 and 9 showed strong cytotoxic activity against MDA cell line (IC50, 0.79, 3.42 µM, respectively) as compared to docetaxel (IC50, 3.98 µM). 相似文献
74.
Abdou O. Abdelhamid Mamdouh A. M. Afifi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2703-2713
2-[1,2-Diaza-3-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))prop-2-enylidene]-3-phenyl-5-substituted 1,3,4-thiadiazolines and 2-{[4-(2,3-dimethyl-5-oxo-1-phenyl(3-pyrazolin-4-yl))(1,3-thiazol-2-yl)]cyanomethylene}-3-phenyl-5-substitu- ted 1,3,4-thiadiazolines were synthesized from hydrazonoyl halides and 4-{-2-aza-2-[(methylthiothioxomethyl)amino]vinyl}-2,3-dimethyl-1-phenyl-3-pyrazoin-5-one and 2-[4-(2,3-dimethyl-5-oxo-1-phenyl-3-pyrazolin-4-yl)-1,3-thiazol-2-yl]ethane-nitrile, respectively. All synthesize compounds were elucidated by elemental analysis, spectra, and alternative synthesis routes, whenever possible. 相似文献
75.
M. Abdelhamid S. Grassini E. Angelini G.M. Ingo M.A. Harith 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010
Laser-induced breakdown spectroscopy (LIBS) is a relatively novel technique that is being applied to the characterization of interfaces in layered materials as an alternative to other classic surface analytical techniques. 相似文献
76.
Teresa López‐León Dr. Delfina Bastos‐González Dr. Juan Luis Ortega‐Vinuesa Dr. Abdelhamid Elaïssari Prof. 《Chemphyschem》2010,11(1):188-194
Poly(N‐isopropylacrylamide) (PNIPAM) is well known to exhibit reentrant behavior or cononsolvency in response to the composition of a mixed solvent consisting of water and a low‐chain alcohol. Since the solvent structure plays an important role in this phenomenon, the presence of structure‐breaking/structure‐making ions in solution is expected to have a dramatic effect on the cononsolvency of PNIPAM. The present work examines the way that the presence of different salts can modify the reentrant‐phase diagram displayed by a cationic PNIPAM microgel in the mixed ethanol/water solvent. The effects of four Hofmeister anions—SO42?, Cl?, NO3? and SCN?—with different abilities to modify the solvent structure are analyzed. The species with kosmotropic or structure‐making character show a clear competition with ethanol for the water molecules, intensifying the nonsolvency of the PNIPAM with the EtOH volume fraction (?e). However, striking results are found with the most chaotropic or structure‐breaking anion, SCN?. In contrast to what happens in water‐rich solutions, the presence of SCN? in alcohol‐rich solvents enhances the solubility of the polymer, which macroscopically results in the microgel swelling. Moreover, this ion displays great stabilizing properties when ?e> is 0.2. These results have been explained by considering how chaotropic or structure‐breaking ions interact with water and ethanol molecules. 相似文献
77.
We present a sensitive measurement of the dissipation and the effective viscosity of a simple confined liquid (octamethylcyclotetrasiloxane) using an atomic force microscope. The experimental data show that the damping and the effective viscosity increase and present oscillations as the gap between the cantilever tip and the surface is diminished. To our knowledge, the damping and the viscosity modulation are reported here with such good accuracy for the first time. Such an experimental result is different from what has been reported earlier where only a continuous increase of the damping and the viscosity are observed. 相似文献
78.
Mediterranean Journal of Mathematics - We consider degenerate parabolic equations with nonsmooth right hand parts of a special form. We derive unique solvability of the Cauchy problem and an... 相似文献
79.
Marzouki H Khaldi A Falconieri D Piras A Marongiu B Molicotti P Zanetti S 《Natural product communications》2010,5(12):1955-1958
The essential oils and supercritical CO2 extracts of wild Daucus carota L. subsp. carota from two different sites in Tunisia were investigated. The main components of the essential oil of the flowering and mature umbels with seeds from Sejnane were eudesm-7(11)-en-4-ol (8.2 - 8.5%), carotol (3.5 - 5.2%), sabinene (12.0 -14.5%), a-selinene (7.4 - 8.6) and 11-alpha-(H)-himachal-4-en-1-beta-ol (12.7 - 17.4%), whereas the oils from Tunis were predominantly composed of elemicin (31.5 - 35.3%) and carotol (48.0 - 55.7%). The antimicrobial activity of the essential oils were assayed by using the broth dilution method on Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and clinical strains of Candida albicans and C. tropicalis 1011 RM. The MIC values obtained were all > 2.5% (v/v). 相似文献
80.
Slaheddine Chaabouni Jean Michel Savariault Abdelhamid Ben Salah 《Journal of chemical crystallography》2004,34(3):223-227
The salt di(N-benzyl piperidinium) pentachloroantimonate(III) dihydrate crystallizes in the orthorhombic system with space group Cmc21, the unit cell dimensions are: a = 29.383(1), b = 10.509(2), c = 9.941(1) Å, with Z = 8. The structure shows a layer arrangement perpendicular to the a axis: planes of SbCl6 octahedra alternate with planes of [C12H17N]+ cations. The SbCl6 octahedra are connected through a O(W)–HCl hydrogen bonds and a chlorine bridge, so that infinite unidimensional chains of composition [SbCl5(H2O)2]2n–
n are formed in the structure along the c direction. These chains are connected to [C12H17N]+ entities by N–HCl and N–HO(W) hydrogen bonds, forming a three-dimensional network. It was found that lengths of Sb–Cl bonds may differ from each other. The differences shown as a distortion of the SbCl6 octahedra were attributed to the Sb(III) lone electron pair stereoactivity. 相似文献