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61.
K. Nagashima 《Optics & Laser Technology》2003,35(3):181-186
Creation of Fresnel off-axis computer-generated holograms and improvement of images reconstructed from the holograms are described. To improve the reconstructed images, we have created the holograms with high construct diffraction patterns by using a histogram method. From reconstruction experiments of the holograms, clear images have been obtained and 3D images have been seen directly with eyes. 相似文献
62.
Reference electrodes for room temperature ionic liquid (RTIL) applications were constructed that have a known and reproducible potential versus the ferrocene/ferrocenium couple. They are based on reference electrodes of the first kind, Ag/Ag+ couple type, or of the second kind, based on Ag/AgCl in M+Cl?. The former uses AgNO3 salt and the latter tetrabutylammonium chloride, Bu4NCl, dissolved in acetonitrile which are then introduced to the ionic liquid of choice for a final concentration of 0.1 M. The reference electrodes can be easily and reproducibly constructed. An ionic contact of these reference systems with the test electrolyte was made using an asbestos fiber liquid junction. The internal compartment of the reference system was filled with the same ionic liquid as used for the electrochemical experiment. The performance of these reference electrodes was tested in selected ionic liquids using the ferrocene/ferrocenium redox couple. The stability, reproducibility, and temperature behavior of the two reference systems have been characterized in the following ionic liquids: 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIBF4), 1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI(CF3SO2)2N), and 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIPF6). It has been found that the formal potentials of the examined reference systems are stable over several days. There is a linear relationship for the temperature studied in the range from 25 to 60 °C. 相似文献
63.
Generalized linear mixed models (GLMMs) have been applied widely in the analysis of longitudinal data. This model confers
two important advantages, namely, the flexibility to include random effects and the ability to make inference about complex
covariances. In practice, however, the inference of variance components can be a difficult task due to the complexity of the
model itself and the dimensionality of the covariance matrix of random effects. Here we first discuss for GLMMs the relation
between Bayesian posterior estimates and penalized quasi-likelihood (PQL) estimates, based on the generalization of Harville’s
result for general linear models. Next, we perform fully Bayesian analyses for the random covariance matrix using three different
reference priors, two with Jeffreys’ priors derived from approximate likelihoods and one with the approximate uniform shrinkage
prior. Computations are carried out via the combination of asymptotic approximations and Markov chain Monte Carlo methods.
Under the criterion of the squared Euclidean norm, we compare the performances of Bayesian estimates of variance components
with that of PQL estimates when the responses are non-normal, and with that of the restricted maximum likelihood (REML) estimates
when data are assumed normal. Three applications and simulations of binary, normal, and count responses with multiple random
effects and of small sample sizes are illustrated. The analyses examine the differences in estimation performance when the
covariance structure is complex, and demonstrate the equivalence between PQL and the posterior modes when the former can be
derived. The results also show that the Bayesian approach, particularly under the approximate Jeffreys’ priors, outperforms
other procedures. 相似文献
64.
三维形貌检测的自动参考栅象法研究 总被引:5,自引:2,他引:3
本文提出了一种用于曲面形貌检测的傅里叶变换法中的参考栅象图的自动产生及误差修正方法,通过对实际测量图象的处理,证明该方法具有很好的使用效果,从而大大提高了傅里叶变换法检测曲面形貌的精度和实用性。 相似文献
65.
The role of matrix reference materials in the process of demonstrating the degree of equivalence of measurement results obtained
from intercomparisons is outlined, reviewing exemplary selected experience gained at BAM regarding the determination of organic
contaminants in environmental matrices.
The specific characteristics of reference materials employed in the process of demonstrating equivalence between laboratories
in the course of proficiency testing as well as the development, comparison and validation of methods are elaborated. The
demand is for series of appropriately characterised samples which are fit for the purpose and it is seen from representative
examples that the utilisation of such tailor-made RM designed to tackle the specific need of an analytical problem dominates
over certified matrix reference materials in this context. Concluding, the role of certified matrix reference materials in
quality assurance is briefly looked at both from the user’s and providers’ points of view.
Received: 9 September 2002 Accepted: 16 December 2002
Presented at CERMM-3, Central European Reference Materials and Measurements Conference: The function of reference materials
in the measurement process, May 30–June 1, 2002, Rogaška Slatina, Slovenia
Correspondence to R. Becker 相似文献
66.
Prasenjit Mandal Rupali Kaul Tarun Jain 《European Journal of Operational Research》2018,264(1):181-199
In this paper, we study the newsvendor’s pricing and stocking decisions under reference point effects. The demand faced by the newsvendor is endogenous and the customers may also decide to procure the product from an outside option. We characterize the firm’s optimal pricing and stocking decisions. Our analysis reveals a threshold policy on the firm’s ordering and pricing decisions while considering the impact of reference point effects. We also find that as the level of optimism increases, the firm’s optimal ordering level decreases and optimal price increases. We further study the impact of loss aversion on the firm’s ordering and pricing decisions. 相似文献
67.
68.
This paper presents a new Transmitted Reference (TR) Ultra-WideBand (UWB) receiver based on Spatial Diversity (SD), which employs Multi-Antenna Technology (MAT) to improve the performance of TR-UWB receiver. According to the amplitude of correlator output of every antenna branch, this paper analyzed the performances of the proposed TR-UWB receiver employing three different kinds of combina-tion strategies, i.e., Maximum Ratio Combination (MRC), Equal Gain Combination (EGC), and Selective Combination (SC), which are different from conventional ones, and theoretically proved that the performance of EGC is better than MRC. Simulation results verify that when EGC is adopted and BER=10–3, increasing three antennas provides Signal to Noise Ratio (SNR) gain of about 3 dB in CM4 channel and SNR gain of about 2 dB in CM2 channel. 相似文献
69.
《Operations Research Letters》2020,48(6):787-791
We analyze the equilibrium of a behavioral newsvendor game featuring oligopoly competition, where each newsvendor’s decision is driven by a reference effect regarding her potential profit. We find that the equilibrium order quantities are characterized by behavioral critical fractiles, where each newsvendor only accounts for the actions of competitors with smaller behavioral critical fractiles. Our result generalizes findings from recent literature on duopoly newsvendor competition with reference effects. 相似文献
70.
Expected utility theory with a smooth utility function predicts that, when allocating wealth between a risky and a riskless asset, investors allocate a positive amount to the risky asset whenever its expected return exceeds the riskless rate of return. A large number of people invest none of their wealth in risky assets, though, leading to the ”participation puzzle.” This paper explores whether the participation puzzle can be addressed when the utility function has a kink at the reference wealth level. It shows that when the reference wealth level is initial wealth increased by the riskless rate of return, there exists a range of expected excess returns for the risky asset for which the investor takes no position. Moreover, this range of expected excess returns is described by comparing a common performance measure of stock returns, the Omega Function, to a function of preference parameters. However, if the reference wealth level is any other constant, the usual expected utility prediction holds and investors allocate at least some of their wealth to the risky asset whenever it has a positive expected excess return. 相似文献