全文获取类型
收费全文 | 156篇 |
免费 | 2篇 |
专业分类
化学 | 110篇 |
晶体学 | 6篇 |
力学 | 5篇 |
数学 | 9篇 |
物理学 | 28篇 |
出版年
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 2篇 |
2013年 | 5篇 |
2012年 | 15篇 |
2011年 | 7篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
1961年 | 2篇 |
1960年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有158条查询结果,搜索用时 15 毫秒
61.
Tiruchinapally G Yin Z El-Dakdouki M Wang Z Huang X 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(36):10106-10112
Traditional chemical synthesis of heparin oligosaccharides first involves assembly of the full length oligosaccharide backbone followed by sulfation. Herein, we report an alternative strategy in which the O-sulfate was introduced onto glycosyl building blocks as a trichloroethyl ester prior to assembly of the full length oligosaccharide. This allowed divergent preparation of both sulfated and non-sulfated building blocks from common advanced intermediates. The O-sulfate esters were found to be stable during glycosylation as well as typical synthetic manipulations encountered during heparin oligosaccharide synthesis. Furthermore, the presence of sulfate esters in both glycosyl donors and acceptors did not adversely affect the glycosylation yields, which enabled us to assemble multiple heparin oligosaccharides with preinstalled 6-O-sulfates. 相似文献
62.
Vinod Kumar Yata P. Gopinath Siddhartha Sankar Ghosh 《Applied biochemistry and biotechnology》2012,167(7):2103-2116
Nonmammalian cytosine deaminases (CDs) have been investigated for last 30?years in the context of cancer therapy. The therapeutic effect of CD is based on its ability to catalyze the conversion of nontoxic prodrug 5-fluorocytosine (5FC) into the anticancer drug 5-fluorouracil (5FU) by deamination of the number 4 carbon of 5FC. This deamination property of CD has been explored to develop innovative therapeutic approach for treatment of cancer. A general overview is needed for the identification of efficient cytosine deaminases for potential use in cancer therapy. In this review, we have discussed about nonmammalian CDs for a variety of prodrug gene/enzyme therapy applications with several recent examples. Finally, we have provided a prospective on the future aspects of CDs and their applications in cancer therapy. 相似文献
63.
KS Thushara ES Gnanakumar R Mathew TG Ajithkumar PR Rajamohanan S Bhaduri CS Gopinath 《Dalton transactions (Cambridge, England : 2003)》2012,41(37):11311-11318
A new molecular adduct of MgCl(2) with isobutanol, namely MgCl(2)·4((CH(3))(2)CHCH(2)OH) (MgiBOH), has been prepared as a precursor to the supporting material for an olefin polymerization catalyst. The MgiBOH adduct and final titanated Ziegler-Natta catalysts have been thoroughly characterized by powder XRD, thermal analysis, Raman spectroscopy and solid-state NMR for structural and spectroscopy aspects. A peak observed at 712 cm(-1) in the Raman spectra of MgiBOH indicates the characteristic Mg-O(6) breathing mode and the formation of the adduct. The diffraction feature at 2θ = 7.8° (d = 11.223 ?) in the XRD confirms the adduct formation and the layered structure. The aim of the present article is to study how the insertion of a bulky isobutanol moiety affects the structural and electronic properties of the MgCl(2)·isobutanol molecular adduct. Indeed, the focus of the present study is to explore how the presence of isobutanol, in the initial molecular adduct, influences the final Z-N catalyst properties and its activity. 相似文献
64.
65.
T. Suresh S. Vetrivel S. Gopinath R.U. Mullai 《Chinese Journal of Physics (Taipei)》2018,56(6):2773-2781
Single crystal of l-Asparagine Indium chloride (LAIn), a new semi-organic crystal was grown by slow evaporation method with deionized water as solvent at ambient condition. The crystal structure of LAIn has been determined by single crystal X-ray diffraction and the result shows that the crystal belongs to the orthorhombic system with P212121 space group. The crystalline nature of grown crystal was analyzed by powder X-ray diffraction analysis. Optical parameters, such as absorbance, transmittance and optical band gap energy were analyzed using UV–Vis NIR transmittance data at the range of 190–800?nm. The ultraviolet (UV) emission nature of the sample was established from the sharp emission peaks in photoluminescence (PL) spectrum. The photo conductivity test exhibits that the grown crystal has positive photo conductive nature. The induced surface laser damage threshold (LDT) for the grown crystal was measured using Nd:YAG laser. The nonlinear optical efficiency of the LAIn crystal was studied using modified Kurtz-Perry powder technique. The hardness, Meyer index, yield strength and elastic stiffness constant were calculated for the grown crystal using Vickers microhardness tester. The variation of dielectric constant and dielectric loss of the grown crystals as a function of frequency has been investigated at different temperatures. The melting point and thermal stability of the LAIn single crystal have been studied by thermo gravimetric analysis and differential thermal analysis (TG/DTA). 相似文献
66.
Odeh Ali Abu Al-Douri Y. Voon C. H. Mat Ayub R. Gopinath Subash C. B. Odeh Raed Abu Ameri M. Bouhemadou A. 《Mikrochimica acta》2017,184(7):2211-2218
Microchimica Acta - The authors describe an integrated biosensor for amperometric DNA detection of Dengue virus in real time. Cu2CdSnS4 (CCTS) quaternary alloy nanostructures were successfully... 相似文献
67.
R.C. Issac G.K. Varier P. Gopinath S.S. Harilal V.P.N. Nampoori C.P.G. Vallabhan 《Applied Physics A: Materials Science & Processing》1998,67(5):557-561
17 cm-3 and it is found that the density increases as a function of distance away from the target. Dependence of probe current on
laser intensity shows plasma shielding at high laser intensities.
Received: 5 January 1998/Accepted: 3 July 1998 相似文献
68.
Rajesh Gopinath Nakka Lingaiah I. Suryanarayana Potharaju S. Sai Prasad 《Reaction Kinetics and Catalysis Letters》2003,79(1):61-68
Catalysts containing 10 wt. % Pd supported on Nb2O5 were prepared by microwave irradiation and conventional electrical heating, using palladium chloride as the precursor for
Pd. Whereas higher residual chloride content decreased the activity and stability of the microwave irradiated catalyst, formation
of PdO during calcination in air improved the performance of the conventionally heated catalyst. Calcination after microwave
irradiation offers the highest activity and stability.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
69.
The structure (I) assigned to the alkaloid avicine has been confirmed by a synthesis of oxyavicine (III). 相似文献
70.
N. Gopinath G. A. Rama Rao V. K. Manchanda P. R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》1985,96(3):273-280
The potentiometric determination of uranium is widely carried out in phosphoric acid medium to suppress the interferences of plutonium by complexation. Owing to the complexity of the recycling plutonium from the phosphate based waste involving manifold stages of separation, a method has been proposed in the present paper which does not use phosphoric acid. Uranium and plutonium are reduced to U/IV/ and Pu/III/ in 1M H2SO4 by Ti/III/, and NaNO2 is chosen to selectively oxidize Pu/III/ and the excess of Ti/III/. The unreacted NaNO2 is destroyed by sulphamic acid and excess Fe/III/ is added following dilution. The equivalent amount of Fe/II/ thus liberated is titrated against standard K2Cr2O7. R.S.D. obtained for the determination of uranium /1–2 mg/ is 0.3% with plutonium being present upto 4.0 mg. 相似文献