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排序方式: 共有84条查询结果,搜索用时 31 毫秒
1.
Gelation Properties of Ovalbumin as Affected by Fatty Acid Salts   总被引:2,自引:0,他引:2  
The physicochemical properties of heat-induced ovalbumin (OVA) gels containing fatty acid salts (FAS) were investigated. Water-holding ability and transparency markedly increased in the presence of sodium caprate or sodium laurate. At 9% of the protein concentration transparent and hard gels formed; at 7%, transparent and soft gels formed. Scanning electron microscopy showed that the transparent gels had a more homogeneous structure than turbid gels without FAS. Differential scanning calorimetry indicated that denaturation temperature of OVA was decreased and the peaks became broader after addition of FAS.  相似文献   
2.
The paper describes the spontaneous emission from a three-level atom placed in a periodic dielectric microstructure which exhibits a complete three-dimensional photonic band gap. By using the Euler approach, the upper level population of the atom is calculated for a wide range of relationships between the Rabi frequency and the detuning of the atomic transition frequency from the upper band edge. The results indicate that there are three cases of the relationship between Rabi frequency and detuning, which determine distinctive states of the atomic population in the long-time limit. When the detuning is greater than the Rabi frequency, the upper level has a zero steady-state atomic population, which leads to enhancement of spontaneous emission. When the magnitude of the detuning is less than the Rabi frequency, the upper level has a nonzero steady-state atomic population, which leads to suppression of spontaneous emission. When the negative detuning is greater than the Rabi frequency, the upper level has a nondecaying oscillatory-state atomic population due to long-time atomic splitting. These three properties of the spontaneous emission are relevant to several optical devices on an atomic scale, such as optical memories, switches and clocks.  相似文献   
3.
A systematic procedure is considered for the synthesis of a stabilizing control method for a multimachine power system with phase shifter, taking into account the velocity governor. A new approach is presented, which uses a coordinate-transformation technique and an optimization technique. The application of this method to a stabilizing control problem for a power system is illustrated by considering a 3-machine power system with phase-shifter control, taking into account an additional control vector for the governing system with one time constant. The synthesized controls are then used to improve the power-system transient stability to a remarkable degree and to restore the power-system transients rapidly to the stable-equilibrium point. Numerical results arc given.  相似文献   
4.
Fractional‐slot windings are widely used in rotating machines in order to improve the output voltage waveform, increase the design flexibility, and gain many other advantages. However, fractional‐slot windings are known to produce different harmonic components such as an even order and/or fractional number of space flux harmonics compared to integral‐slot windings. These harmonics may increase stray losses and cause stator core vibration. This paper describes an analysis of space flux harmonics and proposes new winding methods such as “novel interspersed windings” to reduce these harmonic components. The proposed winding methods were verified by numerical analysis and model tests.  相似文献   
5.
This paper applies ISM (interpretive structural modelling) to analyse preference structure in a multiobjective problem of a dynamic environmental-economic model, and terms this method IPSM (interpretive preference structural modelling). Multi-objectives in the model include minimizing social cost of pollution, and maximizing total consumption in a planning interval. IPSM analyses decision-maker's preference relations (mental model) among many Pareto-optimal solutions of the multiobjective systems under the interactive cooperation between the decision-maker and the model-builder, and extracts the decision-maker's preference structure as a hierarchical directed graph, where the vertices of the graph correspond to the Pareto-optimal solutions and the directed edges correspond to the preference relations. An interesting economic interpretation for a preferred solution is discussed in terms of the economic interpretation of the discrete minimum principle.  相似文献   
6.
This paper presents the development results of a ?1 MV dc filter and dc measurement systems for an ITER (International Thermonuclear Experimental Reactor) neutral beam injector (NBI) system. High accuracy of 0.5% and fast responsivity of 3.3 μs, ?3 dB are required for the dc measurement systems: both dc voltage dividers and DCCTs. Circuit design and thermal flow design were carried out to clarify and minimize their effects on the accuracy and responsivity. The validity of the established design was demonstrated by the actual‐product tests; temperature rise of each components fell below the allowable value; inner components of dc filter withstood dc ?1.2 MV; each voltage divider accurately measured the voltage during the dc ?1.2 MV withstand voltage test; the voltage dividers and the DCCTs were adequate to the requirements of responsivity (3.3 μs, ?3 dB).  相似文献   
7.
We develop a self-tuning-type adaptive control for robotic manipulators with six joints, and analyse the stability of the control system. In order to reduce the computational effort for obtaining the control input in real time, a decentralized adaptive control system is designed in which each joint of the manipulator is regarded as a subsystem and controlled independently in parallel. In this control system we regard the interaction among the multiple joints as an unknown input in each subsystem. The influence of the interaction on the stability of the overall control system is analysed using a Lyapunov function. The theoretical result obtained is that the control system is always stable in the sense that the error between the output of the adaptive predictor and the real output (angular velocity of each joint) will not exceed the amount of interaction. This result is verified by some simulation studies.  相似文献   
8.
The design problem of servo systems for distributed parameter systems is investigated. The output regulator of integral type is designed in order to guarantee internal stability and output regulation. The design procedure based on a dynamic stabilizing compensator is discussed. The output regulation of a wide class of distributed parameter systems is proved under the condition that a closed-loop system is stabilized by a dynamic compensator of general type. Then a closed-loop system can be stabilized by a finite dimensional dynamic compensator under some additional conditions. The reducabitity of the design procedure to a purely finite dimensional one is discussed.  相似文献   
9.
Abstract

This paper deals with the prediction and management of regional and environmental noise using remote sensing techniques. Landsat-MSS and -TM data are used to estimate noise pollution by means of a group method of data handling. They estimate ground roughness from the proportion of the area occupied by buildings thus determining the shielding factor of noise propagation on the ground. The noise level predicted by the method presented in this paper showed a satisfactory agreement with that obtained from measurements from various other cases in urban areas.  相似文献   
10.
In order to obtain quantitative relationship between (0002) texture intensity and hot rolling conditions, conventional rolling experiments on AZ31 magnesium alloys were performed with 20%–40% reductions and temperatures within the range of 300–500 °C. Shear strain and equivalent strain distributions along the thickness of the rolled sheets were calculated experimentally using embedded pin in a rolling sheet. Rolling microstructures and textures in the sheet surface and center layers of the AZ31 alloys were measured by optical microscopy (OM), X-ray diffractometry (XRD) and electron back scatter diffraction (EBSD). Effects of the rolling strain, dynamic recrystallization (DRX) and twinning on the texture evolution of the AZ31 alloys were investigated quantitatively. It is found that the highest (0002) basal texture intensities are obtained at a starting rolling temperature of 400 °C under the same strain. Strain–temperature dependency of the (0002) texture intensity of the AZ31 alloy is derived.  相似文献   
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