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31.
Frontispiece: Electrochemiluminescence Bioassays with a Water‐Soluble Luminol Derivative Can Outperform Fluorescence Assays
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R. McCaffer M. J. McCaffrey A. Thorpe 《The Journal of the Operational Research Society》1984,35(5):415-424
Predictions of the tender price of proposed buildings are needed during early design. Conventionally, these are prepared manually and based on limited data.A computer system was produced which prepares estimates using a library of data containing rate, quantity and date for the constituent elements of previous buildings, inflation indices and statistical models.Because the scatter of the rate vs quantity data for each element in a sample of buildings was so variable between samples, no one model was adequate. Thirty two different models were included, together with a criterion for selecting the most appropriate. This ensured the most precise prediction possible.The co-efficient of variation of the ratio forecast to actual price measured for a set of system-produced estimates grouped by building type ranged from 10 to 19%. Current manual practice ranges from 6 to 21%, but this is only achieved much later when design is complete and more reliable data is available. 相似文献
35.
Changes of the refractive index for homologous series of hydrocarbons are usually plotted versus the density. While there is a clear linear dependence for alkanes and alkenes, the linearity deteriorates for homologous series with functional groups involving heteroatoms. The slope can even become negative, e. g., for carboxylic acids. For gaining a deeper understanding and to establish a more general correlation, we reinvestigate the corresponding theories starting with the Newton-Laplace, Gladstone-Dale and the Lorentz-Lorenz rules. We revisit the concept of molar refractivity pioneered by Landolt and Brühl and show that it is closely connected with a twin of Beer's law. We conclude that the refractive index of homologues series should better be plotted versus the molar concentration of the main UV-chromophore, the C−H bond, which actually causes the refractive index changes. This new approach is not limited to alkanes and alkenes but holds for homologous series with functional groups including heteroatoms. 相似文献
36.
Synthesis of a Two‐Dimensional Covalent Organic Monolayer through Dynamic Imine Chemistry at the Air/Water Interface
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Wenyang Dai Feng Shao Jacek Szczerbiński Ryan McCaffrey Prof. Dr. Renato Zenobi Dr. Yinghua Jin Prof. Dr. A. Dieter Schlüter Prof. Dr. Wei Zhang 《Angewandte Chemie (International ed. in English)》2016,55(1):213-217
A two‐dimensional covalent organic monolayer was synthesized from simple aromatic triamine and dialdehyde building blocks by dynamic imine chemistry at the air/water interface (Langmuir–Blodgett method). The obtained monolayer was characterized by optical microscopy, scanning electron microscopy, and atomic force microscopy, which unambiguously confirmed the formation of a large (millimeter range), unimolecularly thin aromatic polyimine sheet. The imine‐linked chemical structure of the obtained monolayer was characterized by tip‐enhanced Raman spectroscopy, and the peak assignment was supported by spectra simulated by density functional theory. Given the modular nature and broad substrate scope of imine formation, the work reported herein opens up many new possibilities for the synthesis of customizable 2D polymers and systematic studies of their structure–property relationships. 相似文献
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Prof. Dr. Bikshandarkoil R. Srinivasan Santosh Y. Shetgaonkar PD Dr. Christian Näther 《无机化学与普通化学杂志》2011,637(1):130-136
The preparation, crystal structures, and thermal properties of [Ca(pyr)2(4‐nba)2]n ( 1 ) (pyr = pyrazole; 4‐nba = 4‐nitrobenzoate) {[Ca(H2O)2(3‐npth)] · H2O}n ( 2 ) (3‐npth = 3‐nitrophthalate), [Mg(H2O)5(3‐npth)] · 2H2O ( 3 ), and [Mg(H2O)4(2‐nba)2] ( 4 ) (2‐nba = 2‐nitrobenzoate) are reported. The anhydrous CaII compound 1 and the diaqua CaII‐3‐nitrophthalate monohydrate 2 are one‐dimensional coordination polymers containing a hexacoordinate CaII ion located on a center of inversion in 1 and a heptacoordinated CaII ion in 2 . In 1 , the 4‐nitrobenzoate moiety acts as a μ2‐bridging bidentate ligand, whereas the 3‐nitrophthalate anion exhibits a μ3‐bridging pentadentate coordination mode in 2 . The hexacoordinate MgII‐containing compounds 3 and 4 do not contain a [Mg(H2O)6]2+ unit and the central MgII ion is coordinated to at least one monodentate carboxylate unit namely the monodentate 3‐npth molecule in 3 and two trans monodentate 2‐nba molecules in 4 . Hydrogen bonding between the lattice water molecules results in the formation of a water dimer in 3 . A comparative study of 17 alkaline earth nitrocarboxylates is described. 相似文献
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Murray C Dozova N McCaffrey JG Shafizadeh N Chin W Broquier M Crépin C 《Physical chemistry chemical physics : PCCP》2011,13(39):17543-17554
The absorption, emission and excitation spectra of ZnPc and H(2)Pc trapped in Ne, N(2), Ar, Kr and Xe matrices have been recorded in the region of the Q states. A comparison of the matrix fluorescence spectra with Raman spectra recorded in KBr pellets reveals very strong similarities. This is entirely consistent with the selection rules and points to the occurrence of only fundamental vibrational transitions in the emission spectra. Based on this behaviour, the vibronic modes in emission have been assigned using results obtained recently on the ground state with large basis-set DFT calculations [Murray et al. PCCP, 12, 10406 (2010)]. Furthermore, the very strong mirror symmetry between excitation and emission has allowed these assignments to be extended to the excitation (absorption) bands. While this approach works well for ZnPc, coupling between the band origin of the S(2)(Q(Y)) state and vibrationally excited levels of S(1)(Q(X)), limits the range of its application in H(2)Pc. The Q(X)/Q(Y) state coupling is analysed from data obtained from site-selective excitation spectra, revealing pronounced matrix and site effects. From this analysis, the splitting of the Q(X) and Q(Y) states has been determined more accurately than in any previous attempts. 相似文献
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The tellurium(II) dithiolates Te[SCH2CH2C(O)OCH3]2, ( 1 ), Te[SCH2CH2CH2SC(O)CH3]2, ( 2 ), and Te[SCH2CH2CH2CH2SC(O)CH3]2, ( 3 ) were synthesized from Te(StBu)2 and the corresponding thiol. All compounds are sensitive toward higher temperatures and light and decompose to elemental tellurium and the disulfide. In the solid state, the Te atom of 1 exhibits the novel Te(S2Te2) coordination mode. Additionally to the two Te—S bonds, each Te atom forms two long Te···Te contacts to neighboring molecules, leading to a coordination number of four and a distorted sawhorse configuration. No intramolecular Te···O interactions are present in the solid state, in accordance with ab initio calculations (MP2/ecp‐basis) for the isolated molecule. 125Te NMR shifts of all compounds lay within a narrow range and close to the respective shift of other Te(SCH2R)2 compounds. VT 125Te NMR spectra gave no hint to donor acceptor interactions in solution for any of the compounds and thus corroborate results from IR‐spectroscopy, ab initio geometry optimizations, and thermochemical calculations. 相似文献