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81.
Richard?D.?AdamsEmail author Erin?Boswell Shaobin?Miao Sanghamitra?Sanyal 《Journal of Cluster Science》2005,16(2):117-126
Two cobalt containing products CpCoMn2(CO)6(μ3-S)2, 2 and Cp2FeCoMn(CO)3(μ3-S)2, 3 were obtained from the reaction of [CpFeMn(CO)5(μ-S2)]2, 1 with CpCo(CO)2 at room temperature. The two rhodium containing products: Cp*RhMn2(CO)6(μ3-S)2, 4 (11% yield) and CpFeCp*RhMn(CO)3(μ3-S)2, 5 (9% yield), were obtained from the reaction of 1 with Cp*Rh(CO)2. Compounds 3 and 5 were characterized structurally by single crystal X-ray diffraction methods. Compounds 3 and 5 both contain triangular clusters of three different types of metal atoms and have triply bridging sulfido ligands on each side of the cluster. A mechanism for their formation from 1 is proposed.†Dedicated to F. A. Cotton on the occasion of his 75th birthday. 相似文献
82.
A novel class of amphiphiles, sodium N-(n-dodecyl-2-aminoethanoyl)-l-amino acidate, have been synthesized. These amphiphiles have been shown to form oil-in-water-type gel emulsions with a high internal-phase ratio in organic solvents as well as in commercial fuels simply by agitation. No heating and cooling cycle was required for the formation of gels. The amphiphiles also showed efficient phase-selective gelation in the presence of excess water. The minimum gelator concentrations for the amphiphiles in the solvents employed have been determined. The effects of the chain length of the hydrocarbon tail and the chirality of a representative amphiphile on its ability to promote gelation in a given organic solvent have been investigated. Also, the effect of acid and alkali on the gelation has been examined. The optical microscopic picture of the gel emulsion showed foamlike structures with oil compartments separated by the continuous aqueous phase. The mechanism of the formation of gel emulsions has been discussed. 相似文献
83.
Sanghamitra Khatua S. N. Mishra S. H. Devare H. G. Devare 《Hyperfine Interactions》1993,78(1-4):553-557
The local susceptibilities (T) of isolated Rh impurities in Pb, Ru, Au, Pd, Pt andYb hosts have been measured as a function of temperature. The results show close to unity for Rh in Pb, Ru, Au andYb indicating nonmagnetic behaviour. In contrast, the magnetic response in exchange enhanced d band metal hosts, e.g. Pd andPt, shows Curie-Weiss-like local susceptibility andreflects a large quasi stable 4d magnetic moment on Rh. 相似文献
84.
Richard D. Adams Burjor Captain O-Sung Kwon Perry J. Pellechia Sanghamitra Sanyal 《Journal of organometallic chemistry》2004,689(8):1370-1376
The reactions of activated CpFeMn(CO)71a and Cp*FeMn(CO)71b, Cp=C5Me5 with thiirane yielded the new dimeric mixed metal disulfido complexes: [CpFeMn(CO)5(μ3-S2)]2 (2) and [Cp*FeMn(CO)5(μ3-S2)]2 (3). Compounds 2 and 3 both contain two triply bridging disulfido ligands. When heated at 40 °C, compound 2 was transformed into a trimeric compound Cp3Fe3Mn3(CO)15(μ3-S2)(μ4-S2)2, 4. Compound 4 contains three disulfido ligands, each of which has a different bridging coordination mode in the six atom metal cluster. There are three inequivalent CpFe(CO)2 groupings linked to a central Mn3(S2)3 core by the disulfido ligands. In solution, compound 4 exhibits a dynamical intramolecular exchange process that interconverts two of the three CpFe(CO)2 groups on the NMR timescale. 相似文献
85.
Choi SH Kim K Jeon J Meka B Bucella D Pang K Khatua S Lee J Churchill DG 《Inorganic chemistry》2008,47(23):11071-11083
We report 16 novel species and 8 molecular structures in studying how meso-thienyl-substituted dipyrrole oxidation, bromination, and metal ion binding impart optical changes, as monitored by UV-vis absorption/emission spectroscopy. Treatment of 4,4-difluoro-8-(3-benzothienyl)-4-bora-3a,4a-diaza-s-indacene (varphi(F) = 0.19) with m-CPBA gives selective S-dioxidation (varphi(F) = 0.006). Results of titrations of transition metal- and "scorpionate"-like dipyrrin species varied under room temperature treatment of m-CPBA. Ni-(thienyl-dipyrrin)(n) (n = 2) degraded significantly in the presence of m-CPBA, whereas related species (M = Cu, Fe, Co; n = 2, 3) were inert. meso-Thienyl group properties were revealed through the use of 3,4,4-triphenyl-8-(thienyl)-4-bora-3a,4a-diaza-s-indacene; Cu(2+) addition resulted in smooth absorption decreases which were modeled to support 1:1 substrate:M(2+) binding; for Hg(2+) 1:2 substrate:M(2+) binding was found. Treatment of 4,4-difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene with Br(2) gave red-shifted UV-vis absorption band features that grow with increasing dipyrrin bromination. Structures of the di- and tetra-substituted bromination products were obtained. 相似文献
86.
Swagatika Satpathy Sanghamitra Pradhan Sujata Mishra 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(3):531-541
The present study aims at investigating the capability of tri-n-butyl phosphate (TBP) in petrofin as extracting agent for La(III) from acidic nitrate medium. The concentrations of TBP and sodium nitrate have positive influence while temperature shows a negative impact on the extraction. The values of standard enthalpy change and entropy change confirm the extraction process as exothermic with a decrease in randomness due to complexation. Regression analysis results fit well with the experimental data in the cases of TBP and nitrate concentration variation. 相似文献
87.
Munmun Khatua Utpal Sarkar Pratim Kumar Chattaraj 《International journal of quantum chemistry》2015,115(3):144-157
Reactivity dynamics and stability of a confined hydrogen molecule in presence of an external magnetic field has been studied using quantum fluid density functional theory. Dynamic profiles of various reactivity parameters such as hardness, electrophilicity, magnetizability, phase volume, entropy, etc. have been studied within a confined environment. Responses in the reactivity parameters as well as the associated electronic structure principles validate the stability of the confined H2 molecule in ground and excited states in presence of an external magnetic field. Confinement to the system has been imposed by the Dirichlet type boundary condition. Confinement and excitation act in opposite directions. Ground state type dynamics is obtained on simultaneous electronic excitation and confinement. © 2014 Wiley Periodicals, Inc. 相似文献
88.
Bitasik Khatua Anjulika Ghosh Anuj Kumar Ray Nayan Banerjee Jayanta Dey Prof. Ankan Paul Prof. Joyram Guin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(19):e202402849
Functionalized primary alkyl chlorides are precursors to a plethora of scaffolds but their access from chemical feedstocks remains challenging. Herein, we report a concise dual Ni/photoredox catalytic protocol for regioselective chlorocarbonylation of unactivated alkenes that enables rapid access to β-keto primary chlorides. The catalytic process features an extensive substrate scope, scalability and functional group tolerance. The Ni/photocatalytic Cl⋅ generation and subsequent cross-coupling is implicated for the process based on the control experiments and DFT study. The synthetic utility of the protocol has been further corroborated through functionalization of complex substrates and modifications of the product. 相似文献
89.
Thermal stability of the blend of polyurethane with three other elastomers, having the reactive functional group, has been
studied. Three different blending techniques have been employed to study the effect of processability on the thermal stability
of the blend. IR spectral analysis revealed that interchain crosslinking takes place between the two elastomer phases. Thermal
stability of the blend increased when preblending and preheating preblending techniques were applied, probably due to the
formation of the interchain crosslink between the elastomer phases.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
90.
Dr. Stewart F. Parker Dr. Sanghamitra Mukhopadhyay Dr. Mónica Jiménez-Ruiz Dr. Peter W. Albers 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(26):6496-6499
The interaction of hydrogen with platinum is enormously important in many areas of catalysis. The most significant of these are in polymer electrolyte membrane fuel cells (PEMFC), in which carbon-supported platinum is used to dissociate hydrogen gas at the anode. The nature of adsorbed hydrogen on platinum has been studied for many years on single-crystal surfaces, on high-surface area-platinum metal (Raney platinum and platinum black), and on supported catalysts. Many forms of vibrational spectroscopy have played a key role in these studies, however, there is still no clear consensus as to the assignment of the spectra. In this work, ab initio molecular dynamics (AIMD) and lattice dynamics were used to study a 1.1 nm nanoparticle, Pt44H80. The results were compared to new inelastic neutron scattering spectra of hydrogen on platinum black and of a carbon-supported platinum fuel cell catalyst and an assignment scheme that rationalises all previous data is proposed. 相似文献