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81.
We investigate the effect of basis set size, correlation effects and interplanar separation on the theoretical electronic structure of stacking complexes of para- and meta-hydroxyaruline with formamidinium cation, constructed as analogs for the complexes of 5- and 6-hydroxytryptamine with imidazolium cation. 相似文献
82.
Sevim Akyüz Andrew B. Dempster J.Eric D. Davies Kerry T. Holmes 《Journal of Molecular Structure》1977
The time-dependent changes which are observed in the infrared and Raman spectra of samples of the two Hofmann aniline clathrates M(NH3)2Ni(CN)4.an2 {M = Cd(II), Ni(II), an = C6H5NH2} indicate the occurrence of a solid state ligand replacement reaction in which the aniline guest molecule replaces the coordinated ammonia to give Man2Ni(CN)4 as the final product. The rate of replacement is greater for the cadmium than for the nickel clathrate, and for both clathrates evacuation of the sample greatly increases the rate of replacement. The Man2Ni(CN)4 complexes can themselves act as host lattices forming clathrates containing guest molecules such as aniline. 相似文献
83.
David P. DiVincenzo 《International Journal of Theoretical Physics》2008,47(8):2130-2132
A tribute to Giuseppe Castagnoli, without whom the historic first workshops on quantum computation in the early 1990s would
not have been possible. 相似文献
84.
We present the network of scientific journals pertaining to Chinese patent data in the period of 1995-2002, in which two journals are considered linked if they have been cited by a common patent. We study a variety of statistical properties of the network of scientific journals of China (NSJC), including degree distribution, local clustering and average degree of the nearest neighbors in the one-mode projected network. Besides this, we generate a weighted network for the NSJC in which the number of common patents citing two particular journals is mapped to line weights. For such a weighted network, distributions of weight, vertex strength, weight per degree, and the relationship between the vertex strength and degree have been analyzed. The above findings show that for the NSJC, small-world behavior is not distinct, while properties of random networks are observed. 相似文献
85.
在TC2理论框架下,计算了在高能正负电子对撞机(LC)上,TC2动力学对味改变中性流过程e+e-→tc产生截面的修正和TC2理论预言的中性top–pionπ0t对该过程产生截面的贡献.计算结果表明:TC2理论对LC实验中tc夸克联合产生的贡献主要来自中性top-pion π0t.在TC2理论的绝大部分参数空间内,可达10-2ph.若假设LC的积分亮度为500fb-1,则每年可产生数千个tc事例.因此,将来的LC实验可作为检验TC2理论的重要工具. 相似文献
86.
Bohrs interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohrs influence, in the pre-war period of 1927–1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglies had no reasonable foundation. But Bohrs interpretation changed little from the time of its first appearance, and stood independent of any philosophical presuppositions. The principle of complementarity is itself best read as a conjecture of unusually wide scope, on the nature and future course of explanations in the sciences (and not only the physical sciences). If it must be judged a failure today, it is not because of any internal inconsistency. 相似文献
87.
Inspired by scientific collaboration networks (SCN), especially our empirical analysis of econophysicists network, an evolutionary model for weighted networks is proposed. Besides a new vertex added in at every time step, old vertices can also attempt to build up new links, or to reconnect the existing links. The number of connections repeated between two nodes is converted into the weight of the link. This provides a natural way for the evolution of link weight. The path-dependent preferential attachment mechanism with local information is also introduced. It increases the clustering coefficient of the network significantly. The model shows the scale-free phenomena in degree and vertex weight distribution. It also gives well qualitatively consistent behavior with the empirical results. 相似文献
88.
The ability of scientific inquiry is one of the important abilities of undergraduate students. We have been thinking and exploring to cultivate students' scientific research ability in the course of laboratory teaching. In recent years, we had carried out persistently reform and practice to the laboratory teaching content and the teaching method in organic chemistry, for example, introduction to the frontier of scientific research, exploring the abnormal phenomena of the experiment, organization of experiment discussion, and carrying out the extracurricular research experiments. The above measures can greatly stimulate the students' interest in learning. Their abilities to think, observe, analyze and solve problems were fully developed. The students' ability of scientific inquiry had been cultivated in multiple aspects. The above measures have effectively promoted the improvement of teaching quality of organic chemistry laboratory course, and also supported the training objectives of high-quality innovative talents in chemistry. 相似文献
89.
《Journal of computational science》2014,5(2):106-118
Satisfying the global throughput targets of scientific applications is an important challenge in high performance computing (HPC) systems. The main difficulty lies in the high number of parameters having an important impact on the overall system performance. These include the number of storage servers, features of communication links, and the number of CPU cores per node, among many others.In this paper we present a model that computes a performance/cost ratio using different hardware configurations and focusing on scientific computing. The main goal of this approach is to balance the trade-off between cost and performance using different combinations of components for building the entire system. The main advantage of our approach is that we simulate different configurations in a complex simulation platform. Therefore, it is not necessary to make an investment until the system computes the different alternatives and the best solutions are suggested. In order to achieve this goal, both the system's architecture and Map-Reduce applications are modeled. The proposed model has been evaluated by building complex systems in a simulated environment using the SIMCAN simulation platform. 相似文献