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81.
Nanoscale molecular cavity in crystalline polymer membranes studied by molecular dynamics simulation
The size, shape, and connectivity of cavities in the crystals of syndiotactic polystyrene were investigated by molecular dynamics simulation. Cluster analysis of the free volume in the crystals clearly reveals the cavity structures: large individual holes are in an orderly manner connected by narrow channels. We call such a cavity structure a ‘molecular cavity’. The diffusion behavior and solubility of gases in the molecular cavity were also simulated. The extremely high solubility of a larger gas and the controllable diffusion path in the narrow channels proved the applicability of the concept of the molecular cavity to high performance separation membranes. 相似文献
82.
Yoshinori Dobashi Kazufumi Kaneda Hideo Yamashita Tomoyuki Nishita† 《Computer Graphics Forum》1996,15(3):109-118
Recently, computer graphics are frequently used for both architectural design and visual environmental assessment. Using computer graphics, designers can easily compare the effect of the natural light on their architectural designs under various conditions, such as different times of day, seasons, atmospheric conditions (clear or overcast sky) or building wall materials. In traditional methods of calculating the luminance due to sky light, however, all calculation must be performed from scratch if such conditions undergo change. Therefore, to compare the architectural designs under different conditions, a great deal of time has to be spent on generating the images. This paper proposes a new method of quickly generating images of an outdoor scene, taking into account glossy specular reflection, even if such conditions change. In this method, luminance due to sky light is expressed by a series of basis functions, and basis luminances corresponding to each basis function are precalculated and stored in a compressed form in the preprocess. Once the basis luminances are calculated, the luminance due to sky light can be quickly calculated by the weighted sum of the basis luminances. Several examples of an architectural design demonstrate the usefulness of the proposed method. 相似文献
83.
Skylight for Interior Lighting Design 总被引:2,自引:0,他引:2
Yoshinori Dobashi Kazufumi Kaneda Takanobu Nakashima Hideo Yamashita Tomoyuki Nishita Kastumi Tadamura 《Computer Graphics Forum》1994,13(3):85-96
It is inevitable for indoor lighting design to render a room lit by natural light, especially for an atelier or an indoor pool where there are many windows. This paper proposes a method for calculating the illuminance due to natural light, i.e. direct sunlight and skylight, passing through transparent planes such as window glass. The proposed method makes it possible to efficiently calculate such illuminance accurately, because it takes into account both non-uniform luminous intensity distribution of skylight and the distribution of transparency of glass according to incident angles of light. Several examples including the lighting design in an indoor pool, are shown to demonstrate the usefulness of the proposed method. 相似文献
84.
The State of the Art of Sludge Drying in Japan 总被引:1,自引:0,他引:1
85.
86.
Measures preventing an earthquake-induced soil liquefaction are of significant importance to mitigate the liquefaction hazards. An air-injection technique may be a simple, inexpensive method - this leads the saturated soils to the desaturated by injecting pressurized air, resulting in a higher liquefaction strength and lower susceptibility. The objective of this study is to investigate the evolution of desaturation process during air injection into saturated soil deposits and verify the validity of a multiphase flow simulator if it is capable of being applied for predicting the process as well as the distribution of degree of saturation after the air injection ceased. In this study simplified model tests that simulate the air injection into saturated soils using air-injection probes, are conducted using two different sizes of soil containers. The experiments using the small container are aimed to examine the nominal rates and magnitudes of the soil desaturation driven by air injection, whilst those with the large container are performed to obtain not only the rates and magnitudes but also the distributions of the desaturated zones within the soil. The results obtained indicate, although clearly depending on the physical properties of targeted soils, that the evolution of desaturation is strongly controlled by the air pressures injected and the soil permeabilities. Numerical analyses are also conducted using a multiphase flow simulator to describe the evolution of the soil desaturation, and to examine the applicability of the model as a prediction tool enabling an evolution of desaturation in situ to be followed with time and space. Predictions show a relatively good agreement with the experimental measurements regarding the rates, magnitudes, and distribution of desaturation specifically for the small-container experiments although predictions of desaturated domain slightly overestimate the measurements for the large-container experiments. Thus, this study indicates that the numerical model described is applicable to field problems when the soil properties in terms of flow transport are well-constrained. 相似文献
87.
88.
Kawahara T. Horiguchi M. Etoh J. Sekiguchi T. Kimura K. Aoki M. 《Solid-State Circuits, IEEE Journal of》1995,30(9):1030-1034
A low-power dynamic termination scheme is proposed and demonstrated as a way to reduce power dissipation for high-speed data transport. In this scheme, the transmission lines are terminated only if the signals change. The gate of a switching MOS transistor connected to a termination resistor is driven by differentiating the transmission signal with a resistor and a capacitor. The power dissipation of the terminating resistor can be reduced to 1/5 in the conventional determination scheme, and overshoot can be reduced to 1/5 that in the open scheme. This scheme is promising for use with palm-top equipment, facilitating high-speed low power operation 相似文献
89.
Yoshinori Iwahashi Zenji Horita Minoru Nemoto Terence G. Langdon 《Metallurgical and Materials Transactions A》1998,29(10):2503-2510
Experiments were undertaken to compare the equal-channel angular (ECA) pressing of Al-1 pct Mg and Al-3 pct Mg solid-solution
alloys with pure Al. The results reveal both similarities and differences between these three materials. Bands of subgrains
are formed in all three materials in a single passage through the die, and these subgrains subsequently evolve, on further
pressings through the die, into an array of grains with high-angle boundaries. However, the addition of magnesium to an aluminum
matrix decreases the rate of recovery and this leads, with an increasing Mg content, both to an increase in the number of
pressings required to establish a homogeneous microstructure and to a decrease in the ultimate equiaxed equilibrium grain
size. It is concluded that alloys exhibiting low rates of recovery should be especially attractive candidate materials for
establishing ultrafine structures through grain refinement using the ECA pressing technique. 相似文献
90.