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121.
This article examines how performance-contingent pricing schemes with long-term statistical performance guarantees can be applied to many IT services. We study two forms of performance-contingent pricing, with rebate proportional to failure rate and fixed rebate for below-threshold performance. We show that threshold-performance contingency pricing can increase both profits and fairness (customers who receive higher benefits pay higher effective price) relative to standard pricing. But an even better solution is to offer a menu of performance guarantees: this can increase the firm’s profit and segment the market. Only service providers whose performance level is sufficiently better than the industry standard can benefit from this pricing mechanism. 相似文献
122.
The thermodynamics of curved boundary layers, with the assumption that the distance between the surface of a fluid cavity and its surface of tension is a quadratic function of the cavity radius, is applied to the exact thermo-dynamic expression forG, the central function of scaled particle theory. The coefficients in the quadratic representation are determined so as to satisfyall five of the known exact conditions onG valid for cavity radii between one-half and one molecular diameter. The results of the calculation are displayed as the hard-sphere equation of state, the boundary tension associated with the surface of tension, and the distance between the cavity surface and the surface of tension. Although the hard-sphere equation of state obtained by this method using all five conditions onG is more accurate than in the case where only two or three conditions are used, the original scaled particle theory, in whichG itself was represented simply by a quadratic function of inverse powers of cavity radius, still yields the more accurate equation of state. Nevertheless, the present approach limits approximations to the distance between the cavity surface and the surface of tension, a small quantity in itself. The path to a still more improved theory remains well defined, contingent upon the discovery of additional exact conditions, and does not depend, as in the original scaled particle theory, on a form forG arrived at in a somewhat ad hoc manner.Research supported under NSF Grant #GP-12408. 相似文献
123.
Expressions for the equilibrium electrode potential of linear N-nuclear complexes with homoredox centers were derived by the theory of the correlated walk as a function of the molar fraction of the oxidized moiety, the nearest-neighbor interaction energies and N. When the interaction energy was large in two-, three- and four-nuclear complexes, the expressions predicted two, three and four voltammetric peaks respectively owing to the formation of mixed valence states. The intuitive extension that the N-nuclear complex might exhibit N peaks was invalid. There were three peaks for any odd number of N. In contrast, four peaks appeared for any even number of N more than 4. For a polynuclear complex with N → ∞, the number of the peaks was reduced to two, as if the complex might be a binucleus. The log plot for the fraction vs. potential curve at large values of N deviated from a straight line. The averaged inverse slope was ca. 90 mV at 25°C. From the concentration distribution of a predominant species varying with the potential, the deviation of the log plot was ascribed to the coexistence of various isomers with different interaction energies. The difference in the voltammetric peak potential was approximately linear with the interaction energy for any N. Approximate equations for the potential difference for N= 2, 3 and 4 were obtained, and were applied to the experimental data available for polyferrocenes. 相似文献
124.
The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially
deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and
temperature. The Fermi energies determined as a function of angular momentum is used to study the dependence of shell correction
on angular momentum using the Strutinsky smoothing procedure. The most important observation is that the shell correction
is almost the same for all spins for 124Ba. The spin cutoff parameter and the single particle level density parameter are studied as a function of spin and temperature.
Constant entropy lines drawn by plotting the excitation energy against angular momentum are found to be roughly at constant
energy above the yrast line and are almost equally spaced. It is observed that no yrast traps are present for 124Ba. 相似文献
125.
烃类化合物NMR化学位移数据库及各类碳氢原子族化学位移统计分布 总被引:7,自引:0,他引:7
以Sadtler标准NMR谱图集为数据源.建立了烃类化合物NMR谱化学位移数据库系统,并利用此数据库系统归纳出了烃类化合物各类碳氢原子族化学位移统计分布图,该统计分布图可用于指导烃类混合物.特别是石油产品NMR谱峰的归属,同时,可提供一条查阅标准图的简捷途径. 相似文献
126.
Karl W. Kratky 《Journal of statistical physics》1982,27(3):533-551
It is well known that the virial coefficients of the pressure of thermodynamic systems can be represented in terms of graphs. The existing graph expansions are compared with a new one, the overlap graph expansion. The merits of overlap graphs in general and especially for hard disks and spheres are discussed. 相似文献
127.
Natsuki Hashitsumae Fumiaki Shibata Mayumi Shing¯u 《Journal of statistical physics》1977,17(4):155-169
A new memoryless expression for the equation of motion for the reduced density matrix is derived. It is equivalent to that proposed by Tokuyama and Mori, but has a more convenient form for the application of the perturbational expansion method. The master equation derived from this form of equation in the first Born approximation is applied to two examples, the Brownian motion of a quantal oscillator and that of a spin. In both examples the master equation is rewritten into the coherent-state representation. A comparison is made with the stochastic theory of the spectral line shape given by Kubo, and it is shown that this theory of the line shape can be incorporated into the framework of the present theory. 相似文献
128.
Rodney J. Baxter 《Journal of statistical physics》1973,9(2):145-182
The order parameter of the two-dimensionalF-model, namely the spontaneous staggered polarizationP
0, is derived exactly. At the critical temperatureP
0 has an essential singularity, bothP
0 and all its derivatives with respect to temperature vanishing. 相似文献
129.
The packing characteristics of process-scale chromatography columns were evaluated using the responses to conductivity-based pulse and step inputs derived from tracer experiments and in-process transitions (i.e. column equilibration and regeneration steps). Characteristics of the measured residence time distributions (RTDs) were quantified by statistical moments and using the equations derived from the Gaussian model. The first and second moments calculated from in-process step transitions for multiple runs were in good agreement with those moments calculated from the pulse-input experiments conducted immediately after column packing. This indicates that most of the time the bed behavior at the time of packing is consistent with that at the time of operation. Due to the significant resistance to protein mass transfer inside the particles, estimated plate heights for protein solutes are expected to be much greater than those observed from the experiments using saltbased tracers. Thus, the column efficiency derived from salt-based experiments can be a useful measure of packing consistency rather than a significant parameter influencing the outcome of protein separations. 相似文献
130.
The last few years have seen a significant increase in publicly available software specifically targeted to the analysis of
extreme values. This reflects the increase in the use of extreme value methodology by the general statistical community. The
software that is available for the analysis of extremes has evolved in essentially independent units, with most forming extensions
of larger software environments. An inevitable consequence is that these units are spread about the statistical landscape.
Scientists seeking to apply extreme value methods must spend considerable time and effort in determining whether the currently
available software can be usefully applied to a given problem. We attempt to simplify this process by reviewing the current
state, and suggest future approaches for software development. These suggestions aim to provide a basis for an initiative
leading to the successful creation and distribution of a flexible and extensible set of tools for extreme value practitioners
and researchers alike. In particular, we propose a collaborative framework for which cooperation between developers is of
fundamental importance.
AMS 2000 Subject Classification Primary—62P99 相似文献