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排序方式: 共有152条查询结果,搜索用时 15 毫秒
31.
Trinadh Kaicharla Tony Roy Manikandan Thangaraj Dr. Rajesh G. Gonnade Dr. Akkattu T. Biju 《Angewandte Chemie (International ed. in English)》2016,55(34):10061-10064
Lewis acid‐catalyzed reactions of 2‐substituted cyclopropane 1,1‐dicarboxylates with 2‐naphthols is reported. The reaction exhibits tunable selectivity depending on the nature of Lewis acid employed and proceed as a dearomatization/rearomatization sequence. With Bi(OTf)3 as the Lewis acid, a highly selective dehydrative [3+2] cyclopentannulation takes place leading to the formation of naphthalene‐fused cyclopentanes. Interestingly, engaging Sc(OTf)3 as the Lewis acid, a Friedel–Crafts‐type addition of 2‐naphthols to cyclopropanes takes place, thus affording functionalized 2‐naphthols. Both reactions furnished the target products in high regioselectivity and moderate to high yields. 相似文献
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33.
Manikantan Syamala K Abe H Fujita Y Tomimoto K Biju V Ishikawa M Ozaki Y Itoh T 《Langmuir : the ACS journal of surfaces and colloids》2012,28(24):8952-8958
We report on plasmon resonance Rayleigh scattering (PRRS) and surface enhanced Raman scattering (SERS) imaging for inhibition assay of yeast cell walls. This assay reveals that the proteins having alkali sensitive linkage bound to β1,3 glucan frameworks in cell walls are involved in SERS activity. The result is further confirmed by comparison of genetically modified cells and wild type cells. Finally, we find that PRRS and SERS spots do not appear on cell walls when daughter cells are enough smaller than parent ones, but appear when size of daughter cells are comparable to parent cells. This finding indicates the relationship between expression of the proteins that generate SERS spots and cell division. These results demonstrate that PRRS and SERS imaging can be a convenient and sensitive method for analysis of cell walls. 相似文献
34.
Biju Joseph K. A. Venkatesan K. Nagarajan T. G. Srinivasan P. R. Vasudeva Rao 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(1):167-171
Lithium assisted electrochemical reduction of U3O8 in the room temperature ionic liquid (RTIL), N-methyl-N-propylpiperidinium bis(trifluoromethylsulfonyl)imide (MPPiNTf2), was studied to explore the feasibility of using RTILs for direct electrochemical reduction of uranium oxide at near ambient
temperature. The electrochemical behavior of Li+ in MPPiNTf2 at stainless steel electrode was investigated by cyclic voltammetry and chronoamperometry. The cyclic voltammogram of LiNTf2 in MPPiNTf2 at 373 K consisted of a surge in cathodic current occurring at a potential of −2.8 V (vs. Fc/Fc+) due to the reduction of Li(I) to metallic form. The nucleation phenomenon observed in the voltammogram was investigated
by chronoamperometry. Electrodeposition of metallic lithium on U3O8 particles contained in a stainless steel (SS) basket was carried out to examine the feasibility of reducing U3O8 to metallic form. The results are discussed in this paper. 相似文献
35.
Itoh T Kikkawa Y Biju V Ishikawa M Ikehata A Ozaki Y 《The journal of physical chemistry. B》2006,110(43):21536-21544
We observed a background luminescence emission that was associated with surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G (R6G) molecules adsorbed on single Ag nanoaggregates and investigated the origin of the background luminescence. Thanks to the observation of single nanoaggregates, we clearly identified nanoaggregate-by-nanoaggregate variations in the steady-state and time-resolved background luminescence spectra of each nanoaggregate. From the variations in the steady-state spectra, two kinds of key properties were revealed. First, the background luminescence spectra were divided into four components: one fluorescence band corresponding to the monomers of R6G and three Lorentzian bands whose maxima were red-shifted from the fluorescence maximum of the monomer by several tens of nanometers. On the basis of the red-shifted luminescence maxima, and experimental and theoretical studies of background luminescence, we attributed the three background luminescences to fluorescence from aggregates (dimer and two kinds of higher-order aggregates) of R6G molecules on an Ag surface. Second, a positive correlation was observed between wavelengths of background luminescence maxima and wavelengths of plasmon resonance maxima. This positive correlation invoked the idea that the dipoles of both the background luminescence and the plasmon radiation are coupled with each other. From the key observations in the steady-state background luminescence spectra, we propose that two factors contribute to the variations in the steady-state background luminescence spectra; one is the aggregation (monomer, dimer, and two kinds of higher-order aggregates) of R6G molecules on an Ag surface, and the other is plasmon resonance maxima of single Ag nanoaggregates. Considering these two factors, we propose that the variations in the time-resolved background luminescence spectra are associated with deaggregation of R6G molecules (higher- to lower-order aggregates) and temporal shifts in the plasmon resonance maxima of single Ag nanoaggregates. 相似文献
36.
Three new homodinuclear lanthanide(III) complexes of xanthene-9-carboxylic acid, [Ln2(XA)6(DMSO)2(H2O)2](Ln = Eu (1), Tb (2) and Gd (3); HXA = xanthene-9-carboxylic acid; DMSO = dimethylsulfoxide), have been synthesized, of which 1 and 2 were structurally characterized by single-crystal X-ray diffraction. These compounds crystallize in the monoclinic space group P21/n with a =17.849(4) A, b = 9.6537(19) A, c = 23.127(5) A, beta = 109.06(3) degrees , and V = 3766.5(13) A3 for 1 and a =17.809(4) A, b = 9.6548(19) A, c = 23.075(5) A, beta = 108.97(3) degrees , and V = 3752.1(13) A3 for 2. The crystal structures of 1 and 2 consist of homodinuclear species that are bridged by two oxygen atoms from two carboxylate ligands. The two lanthanide ions are related by a center of inversion. Each lanthanide ion is coordinated by eight oxygen atoms in an overall distorted square-prismatic geometry. Six of the oxygen atoms are furnished by the carboxylate moieties, and the remaining two oxygen atoms are provided by water and DMSO molecules. The photophysical properties of these complexes in the solid state at room temperature have been investigated. The quantum yields were found to be 0.06 +/- 0.01 and 7.30 +/- 0.73% for 1 and 2, respectively. 相似文献
37.
38.
Shivappa B. Halligudi Biju M. Devassy N.K. Kala Raj Manju P. Degaonkar Sarada Gopinathan 《Reaction Kinetics and Catalysis Letters》2000,71(2):289-294
Oxidation of p-xylene and methyl 4-methylbenzoate were catalyzed by transition metal Schiff-base complexes having the general formula LMCl1–2 (where M = manganese or ruthenium and L = salen, salicylaldehydeethylenediimine, saloph, salicylaldehyde-o-phenylenediimine and EDTA, ethylenediaminetetraacetate) at 150°C and 500 psig air and gave p-toluic acid (> 85 %) and monomethyl terephthalate (> 70%) as the major oxidation products, respectively. 相似文献
39.
Matthijs K.J. ter Wiel Mirjam Arnold Sandra Peter Ingo Troltsch Stefan Merget Florian Glaser Michael Schwarm Harjinder S. Bhatti Biju Kuriakose Suryakant S. Pol Mohanasundaram Balamurugan Viral V. Joshi 《Tetrahedron: Asymmetry》2009,20(4):478-482
A procedure has been developed for the large scale synthesis of enantiopure β3-neopentylglycine and its Cbz-protected derivative. The synthetic route developed in our laboratory features Cbz-protection of the racemic β-amino acid followed by resolution with l-norephedrine and provides the enantiomerically pure Cbz-β-neopentylglycine in good yield and excellent enantiopurity. No toxic or dangerous chemicals are used, allowing the scale-up of this procedure without major safety concerns. 相似文献
40.
Vinoy?Thomas Gijo?Jose Gin?Jose P.?R.?Biju S.?Rajagopal N.?V.?UnnikrishnanEmail author 《Journal of Sol-Gel Science and Technology》2005,33(3):269-274
Silica glasses doped with Dy3+ were prepared by sol–gel method. The FTIR and thermo gravimetric analysis (TGA) clearly show complete densification (density = 2.2 gm/cm3) of the gels around 1000C. The fluorescence properties of Dy3+ ion are utilized to study the structural changes during the gel to glass transition of the silica xerogels. The fluorescence intensity and full width at half maximum (FWHM) of the emission bands show an increasing tendency with heat treatment. This is attributed to a glassy silica network with an asymmetric environment. The (Y/B) ratio for the Dy3+ ion is found to be less sensitive to site symmetry effects. 相似文献