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211.
Excitation functions at seven angles, covering the energy range Ep = 8.5–19.0 MeV, have been measured for 15N(p, no)15O using time-of-flight methods. Angular distributions were also measured at five energies. Activation methods were used to determine the total cross section below the excited-state threshold. Ten resonances were observed, four of which have also been found in 15N(p, γ)16O data. The energies, widths and nucleon widths have been extracted and are used, together with proton capture data, to derive radiative widths for certain levels. 相似文献
212.
In the present work, five systems of samples have been prepared by the solution casting technique. These are the plasticized
poly(methyl methacrylate) (PMMA-EC) system, the LiCF3SO3 salted-poly(methyl methacrylate) (PMMA-LiCF3SO3) system, the LiBF4 salted-poly(methyl methacrylate) (PMMA-LiBF4) system, the LiCF3SO3 salted-poly(methyl methacrylate) containing a fixed amount of plasticizer ([PMMA-EC]-LiCF3SO3) system, and the LiBF4 salted-poly(methyl methacrylate) containing a fixed amount of plasticizer ([PMMA-EC]-LiBF4) system. The conductivities of the films from each system are characterized by impedance spectroscopy. The room temperature
conductivity in the pure PMMA sample and (PMMA-EC) system is 8.57 × 10−13 and 2.71 × 10−11 S cm−1, respectively. The room conductivity for the highest conducting sample in the (PMMA-LiCF3SO3), (PMMA-LiBF4), ([PMMA-EC]-LiCF3SO3), and ([PMMA-EC]-LiBF4) systems is 3.97 × 10−6, 3.66 × 10−7, 3.40 × 10−5, and 4.07 × 10−7 S cm−1, respectively. The increase in conductivity is due to the increase in number of mobile ions, and decrease in conductivity
is attributed to ion association. The increase and decrease in the number of ions can be implied from the dielectric constant,
ɛr-frequency plots. The conductivity–temperature studies are carried out in the temperature range between 303 and 373 K. The
results show that the conductivity is increased when the temperature is increased and obeys Arrhenius rule. The plots of loss
tangent against temperature at a fixed frequency have showed a peak at 333 K for the ([PMMA-EC]-LiBF4) system and a peak at 363 K for the ([PMM-EC]-LiCF3SO3) system. This peak could be attributed to β-relaxation, as the measurements were not carried out up to glass transition temperature,
T
g. It may be inferred that the plasticizer EC has dissociated more LiCF3SO3 than LiBF4 and shifted the loss tangent peak to a higher temperature.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006 相似文献
213.
Kim-Lin Chew Johnny Pang Qizhang Liu Jihong Ou Chung-Piaw Teo 《Annals of Operations Research》2001,108(1-4):111-122
Singapore Mass Rapid Transit (SMRT) operates two train lines with 83 kilometers of track and 48 stations. A total of 77 trains are in operation during peak hours and 41 during off-peak hours. In this article we report on an optimization based approach to develop a computerized train-operator scheduling system that has been implemented at SMRT. The approach involves a bipartite matching algorithm for the generation of night duties and a tabu search algorithm for the generation of day duties. The system automates the train-operator scheduling process at SMRT and produces favorable schedules in comparison with the manual process. It is also able to handle the multiple objectives inherent in the crew scheduling system. While trying to minimize the system wide crew-related costs, the system is also able to address concern with respect to the number of split duties. 相似文献
214.
Size-controlled uniform surface-capped CdS nanoparticles were readily prepared by an improved inverse microemulsion technique using hexanethiol as co-surfactant. The third-order optical nonlinearities were studied for the first time by newly-developed Z-scan technique, from which the enhanced nonlinear optical responses were observed after heat-treatment. 相似文献
215.
T. GuF. Albert W. AugustinY.M.J. Chew M. MayerW.R. Paterson S. SchollI. Sheikh K. WangD.I. Wilson 《Experimental Thermal and Fluid Science》2011,35(3):509-520
Fluid dynamic gauging (FDG) is a non-contact technique for measuring the thickness and strength of fouling layers immersed in liquid in situ. Its application to an annular geometry across a range of possible flow conditions, from stagnant to turbulent flow regimes (annulus Reynolds number ∼29,000), is demonstrated. Two modes of measurement are demonstrated: in the first, the pressure drop across the nozzle is fixed and the mass flow rate of liquid withdrawn through the gauge is measured. In the second, the mass flow rate of liquid is fixed and the pressure drop measured: the latter is a new mode of measurement and it is shown to perform equally well, with advantages for particular applications. The results were not affected significantly by the surface under study being heated, indicating that the technique is suitable for measuring deposit thicknesses insitu during fouling and cleaning experiments in annular devices which are commonly used in deposition studies. Computational fluid dynamics (CFD) simulations, which afford detailed information about the flow patterns and shear stresses imposed on the surface, showed good agreement with experimental data for tests in the laminar regime: simulation of the transitional and turbulent regimes was not attempted. A short study of whey protein fouling recorded mixed success owing to the softness of the deposit, but demonstrated the scope for FDG to monitor the development of fouling layers in these geometries. 相似文献
216.
Reported here are four homochiral and one racemic chiral compounds assembled from transition metals (Fe2+, Co2+, and Ni2+), rigid enantiopure camphoric acid, and flexible 4,4'-trimethylenedipyridine; they feature an unusual homochiral three-dimensional supramolecular assembly (resulting from catenation of 4-connected bilayers) as well as a homochiral 3-fold interpenetrating diamond net and a noninterpenetrating primitive cubic net. 相似文献
217.
Ultra-fine (<1 microm) microfilters are required to effectively trap microbial cells. We designed microfilters featuring a rain drop bypass architecture, which significantly reduces the likelihood of clogging at the cost of limited cell loss. The new rain drop bypass architecture configuration has a substantially lower pressure drop and allows a better efficiency in trapping protozoan cells (Cryptosporidium parvum and Giardia lamblia) in comparison to our previous generation of a microfilter device. A modified version displaying sub-micron filter gaps was adapted to trap and detect bacterial cells (Escherichia coli), through a method of cells labeling, which aims to amplify the fluorescence signal emission and therefore the sensitivity of detection. 相似文献
218.
Ng CH Kong KC Von ST Balraj P Jensen P Thirthagiri E Hamada H Chikira M 《Dalton transactions (Cambridge, England : 2003)》2008,(4):447-454
A series of ternary metal(ii) complexes {M(phen)(edda); 1a (Cu), 1b (Co), 1c (Zn), 1d (Ni); H(2)edda = N,N(')-ethylenediaminediacetic acid} of N,N'-ethylene-bridged diglycine and 1,10-phenanthroline were synthesized and characterized by elemental analysis, FTIR, UV-visible spectroscopy and magnetic susceptibility measurement. The interaction of these complexes with DNA was investigated using CD and EPR spectroscopy. MTT assay results of 1a-1c , screened on MCF-7 cancer cell lines, show that synergy between the metal and ligands results in significant enhancement of their antiproliferative properties. Preliminary results from apoptosis and cell cycle analyses with flow cytometry are reported. seems to be able to induce cell cycle arrest at G(0)/G(1). The crystal structure of 1a is also included. 相似文献
219.
Even though open-framework solids have been made in a variety of compositions such as silicates, phosphates, germanates, borates, and phosphites, few are known that are based on trigonal-pyramidal sulfite anions. We report here the first synthetic and structural studies of metal-organic framework materials in the zinc sulfite composition. It is demonstrated here that Zn2+ and SO32- can form various neutral inorganic subunits that can be 0-D clusters, 1-D chains, or 2-D sheets. These inorganic subunits of different dimensionality can subsequently be connected into extended frameworks of higher dimensionality through bifunctional ligands. In (ZnSO3)2en, infinite corrugated ZnSO3 layers are pillared by ethylenediamine (en) molecules into a 3-D network that can be classified as a (3,4)-connected net based on tetrahedral Zn nodes and trigonal-pyramidal S nodes. In (ZnSO3)pip, infinite ZnSO3 chains are cross-linked with piperazine molecules into a 3-D framework that can be classified as 4-connected net based on tetrahedral Zn nodes only. In (ZnSO3)2(TMDPy)2, (ZnSO3)2 dimers are doubly bridged by trimethylenedipyridine molecules into an infinite chain with a string of circles. Each circle along the chain is interlocked with another circle from a chain in the perpendicular direction, creating a 2-D pattern with an infinite-square array of catenane-like units. 相似文献