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991.
992.
Y. W. Kim 《International Journal of Thermophysics》2007,28(2):732-741
Thermophysical properties are collective measures of a material to transport dynamical quantities of physical nature on its
surface or through the bulk. As such, the exact nature of couplings between particles in a many-body assembly of building
block atoms or molecules sensitively determines their values. The couplings between nearest neighbors are the product of the
local elemental composition and the material phase. In this study, thermal cycling of a four-element Wood’s alloy specimen
brings out cadmium-rich patches to the top surface of the specimen. An assembly of such patches leads to depth-dependent deviations
of elemental composition from that of the bulk. Surface-layer atoms are driven to form a high temperature laser-produced plasma
(LPP), and time-resolved spectroscopy of their emissions show the variability of elemental composition over surface positions
as well as over depth from the surface. These thermal history-driven composition anomalies contribute to significant variability
in the measured values of spectral emissivity and thermal diffusivity. 相似文献
993.
Yu. O. Pyr'ev 《Materials Science》2004,40(1):29-37
We construct the solution of the problem of thermoelastic contact of an inertial cylinder with a rigid bush under the conditions of friction heating and wear. It is assumed that the friction coefficient depends on the relative velocity of contacting bodies. We analyze the stability of stationary solutions, determine contact parameters in the process of nonuniform rotation of the cylinder, and demonstrate the possibility of friction self-oscillations. 相似文献
994.
Current–Voltage (I–V) characteristics have been studied at various temperatures in vacuum evaporated thin films of a-Se85Te15−x
Pb
x
(x = 0, 2, 4, 6) alloys. These characteristics show that, at low electric fields, an ohmic behaviour is observed. However, at
high electric fields (E ∼ 104 V/cm), the current becomes superohmic. At high fields, in case of samples having 0 and 2 at% of Pb, the experimental data
fits well with the theory of space charge limited conduction (SCLC) in case of uniform distribution of localized states in
the mobility gap. Such type of behaviour is not observed at higher concentration of Pb in the present glassy system due to
high conductivity. In these samples, joule heating due to large currents may prohibit the measurement of SCLC. Using the theory
of SCLC for the uniform distribution of the traps, the density of localized defect states near Fermi level is calculated for
these compositions. The results indicate that the density of defect states near Fermi level increases on addition of Pb to
binary Se85Te15alloy. This is explained in terms of electronegativity of Pb as compared to host elements. 相似文献
995.
Éntin S. V. Anzheurov N. M. Krasovitskii Yu. V. Panova O. A. Shcheglova L. I. 《Refractories and Industrial Ceramics》2003,44(3):194-198
An experimental setup for studying filter-assisted dust collection is described. The role of various factors — hydraulic resistance, filtering velocity, dust concentration, pressure drop, efficiency of recovery — in the performance of filters intended for use in the production of refractory materials is considered. The dust removal method was tested under industrial conditions at the Semilukskii Refractory Plant and can be recommended for wider use in different branches of industry. 相似文献
996.
Small and wide-angle X-ray scattering experiments with in-situ deformation of dry flax fibres have been carried out. An increase in the (200) peak intensity during deformation has been attributed to strain-induced crystallisation of the cellulose microfibrils, and provides evidence that the non-crystalline cellulose chains are initially oriented. However, no change in the equatorial small-angle streak (from cellulose microfibrils), the meridional reflection (from a crystalline/non-crystalline repeat along the fibre), or the microfibril orientation was seen. 相似文献
997.
Document image analysis: A primer 总被引:1,自引:0,他引:1
998.
Feature-based classifiers for design optimization 总被引:1,自引:0,他引:1
We present a design optimization method for systems with high-dimensional parameter spaces using inductive decision trees.
The essential idea is to map designs into a relatively low-dimensional feature space, and to derive a classifier to search
for high-performing design alternatives within this space. Unlike learning classifier systems that were pioneered by Holland
and Goldberg, classifiers defined by inductive decision trees were not originally developed for design optimization. In this
paper, we explore modifications to such classifiers to make them more effective in the optimization problem. We expand the
notions of feature space, generalize the tree construction heuristic beyond the original information-theoretic definitions,
increase the reliance on domain expertise, and facilitate the transfer of design knowledge between related systems. There
is a relatively small but rapidly growing body of work in the use of inductive trees for engineering design; the method presented
herein is complementary to this research effort. 相似文献
999.
M. Nyoka G. Akdogan R. H. Eric N. Sutcliffe 《Metallurgical and Materials Transactions B》2003,34(6):833-842
The process of mixing and solid-liquid mass transfer in a one-fifth scale water model of a 100-ton Creusot-Loire Uddeholm
(CLU) converter was investigated. The modified Froude number was used to relate gas flow rates between the model and its protoype.
The influences of gas flow rate between 0.010 and 0.018 m3/s and bath height from 0.50 to 0.70 m on mixing time were examined. The results indicated that mixing time decreased with
increasing gas flow rate and increased with increasing bath height. The mixing time results were evaluated in terms of specific
energy input and the following correlation was proposed for estimating mixing times in the model CLU converter: T
mix=1.08Q
−1.05
W
0.35, where Q (m3/s) is the gas flow rate and W (tons) is the model bath weight. Solid-liquid mass-transfer rates from benzoic acid specimens immersed in the gas-agitated
liquid phase were assessed by a weight loss measurement technique. The calculated mass-transfer coefficients were highest
at the bath surface reaching a value of 6.40 × 10−5 m/s in the sprout region. Mass-transfer coefficients and turbulence parameters decreased with depth, reaching minimum values
at the bottom of the vessel. 相似文献
1000.
A study is made of boron removal from Kizildere/Turkey geothermal waste water using the boron selective resin Amberlite IRA 743. The resin in salt form has no boron removal capacity if the solution is unable to neutralize the released acid during the exhaustion period. In the case of Kizildere waste water, with a pH value of 8.9 and high HCO3− content, single stage regeneration is feasible and the exhausted resin can be regenerated economically. According to a preliminary estimate, the electricity production cost would rise by 1 ¢/kWh. 相似文献