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91.
X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to investigate the reordering process of a partially disordered Ni76Al24 (0.2 wt.%B) powder with annealing times and temperature. The long-range order parameter varied linearly with temperature and a significant ordered state was observed at 773 K. The DSC measurements showed one main exothermal peak in the temperature range of 493–913 K. The maximum rate of energy release occurred at 763 ± 2 K with a total thermal effect of ΔH = 52 ± 9 j/g. The DSC peak showed a shoulder around its maximum temperature of 763 ± 2 K which was attributed to order stabilization. The presence of boron in the alloy enhanced the transformation temperature by increasing the enthalpy of vacancies migration without affecting the reaction enthalpy.  相似文献   
92.
Detecting runtime errors helps avoid the cost of failures and enables systems to perform corrective actions prior to failure occurrences. Control flow errors are major impairments of system dependability during component interactions. Existing control flow monitors are susceptible to false negatives due to possible inaccuracies of the underlying control flow representations. Moreover, avoiding performance overhead and program modifications are major challenges in these monitoring techniques. In this paper, we construct a connection-based signature approach for detecting errors among component interactions. We analyze the monitored system performance and examine the relationship of the captured error state parameters with the system performance deviation. Using the PostgreSQL 8.4.4 open-source database system with randomly injected errors, the experimental evaluation results show a decrease in false negatives using our approach relative to the existing techniques. It also demonstrates a significant ability of identifying the responsible components and error state patterns for system performance deviation.  相似文献   
93.
94.
New vanadate compounds having the molecular structure LixMg1−xV2−xMoxO6 (0 ≤ x ≤ 1) were studied. Six samples were prepared by sol-gel process from precursor using the following ratios of x = 0, 0.2, 0.4, 0.6, 0.8 and 1, respectively. These samples were labeled S1, S2, S3, S4, S5 and S6. The final process of firing occurred at 750 °C for 18 h in air. The prepared materials were characterized by XRD, SEM, IR, electron spin resonance (ESR) and magnetic measurements. The morphologies of S1, S2, S5 and S6 are prismatic as they have monoclinic crystal structures. S3 and S4 differ in the crystal morphology from the other previous samples due to their triclinic crystal lattice structure. IR spectra revealed that the bond lengths of the vanadyl groups νVO, νsy V-O and σV-O increase in the same direction from S1 to S6. The data of the ESR explain the existence of V4+ beside V5+ in S1, S4 and S6 and also presence of Mo5+ with Mo6+ in S4 and S6. S4 exhibited better magnetic susceptibility and saturated magnetization than the other samples. The first specific discharge capacities of the samples were performed. S4 showed the maximum specific capacity of 265 mAh g−1 in comparison with the other samples. Cyclic voltammogram of S4 exhibited the highest current intensity in comparison with the other samples. This sample showed two peaks at 0.53 and 1.3 V versus Li/Li+ characterizing double de-insertions of two lithium atoms from Li1.6Mg0.4V1.4Mo0.6O6−x and Li0.6Mg0.4V1.4Mo0.6O6, respectively. Also, two additional peaks were characterized for the oxidation of Mo5+ to Mo6+ and V4+ to V5+ at 3.5 and 4 V, respectively.  相似文献   
95.
阴极保护—氯盐污染海工混凝土的最佳长效维修解决方案   总被引:1,自引:0,他引:1  
混凝土结构劣化问题如今已成为建筑业面临的最严重的问题和巨大的挑战之一。在过去的30年里,对于遭受氯盐污染的混凝土码头结构,通常采用传统的"打补丁"法维修,即移除爆裂的混凝土,然后用维修砂浆回填。但是对于这些维修过的结构来说,难以得到长期的维修效果。通常在维修后短短几年内,维修过的部位周围又重新需要维修。阴极保护是一种电化学技术,利用直流电流来中止混凝土中钢筋的腐蚀进程。阴极保护方法已经被证明为氯盐污染的结构的最有效、技术上可行的长效修复解决方案。本文将重点介绍钢筋混凝土结构劣化的原因以及修复这些结构的最新方法。  相似文献   
96.
Robotics application in colour recognition using fiber optic cabled sensors interfaced with robot controller and Programmable Logic Controller (PLC) is discussed in this paper. The sensors send input signals to the robot controller and the specified program will be executed with respect to the triggered input. The aim of this research work is to recognize colour by pin point detection and sorting of object specimens with respect to their colour attributes, which includes hue, saturation and luminance level. The controller programs were designed to control the robot and the conveyor belt independently parallel to each other via relays, to be synchronized during operation. Finally, the calculative results were verified experimentally and the real time implementation was carried out. It can be observed how controllers are integrated and synchronized in a system to perform a desired operation without conflict using real time applications such as chemical, pharmaceutical, agricultural, food industries and even recycling.  相似文献   
97.
At physiological hydrogen-ion concentration, p-hydroxybenzoate esters have been found to exert a synergistic effect on the lytic activity of lysozyme; the effect being increased with increasing the size of the aliphatic chain. Although the investigated parabens were proved to bind in significant quantities with lysozyme, however, such additives fail to mask the formation of substrate-lysozyme complexes. The observation was further extended to some organic mercurials with essentially similar results.

At different enzyme concentration levels, phonylmercuric acetate was proved to be the most superior potentiator, whereas, methyl paraben displayed a negligible role.

in the light of the findings obtained, the synergistic effect was interpreted on the basis of the preferential orientation of the substrate on the enzyme binding sites. Such an orientation seems to be more accessible in presence of preservatives.  相似文献   
98.
Knowledge-based neural networks (KBNNs) can be used as expert system knowledge bases. This approach shifts the interests in using connectionist knowledge bases for inferencing in an interactive fashion and giving reasonable justifications for their conclusions. The primary goal of this article is to present a good inference and control mechanism for such knowledge bases. For this purpose, the article develops a stand alone inference engine that uses a connectionist knowledge base, seeks to reduce the amount of data requested in order to reach a conclusion, and explains how a particular conclusion was reached. The inference engine was evaluated on illustrative example applications. Results obtained demonstrate that in spite of its simplicity the presented technique is superior to other techniques over sparse input knowledge bases.  相似文献   
99.
Abstract

Water scarcity in Jordan is a significant constraint to development, with limited available water and financial resources. As population and economic activity increase, it will be necessary to implement national strategies that seek to balance the present needs and those of future generations. Multiple variables associated with agricultural crops, industries, and the impact of climate change, were incorporated into a Decision Support System (DSS). The DSS utilized Analytical Hierarchy Process (AHP), which resulted in the prioritization of sustainable water policies for management in the Azraq Basin. The inputs to the DSS were generated through application of Modflow (groundwater), stochastic, and Penman Montieth models and through calculations of water productivity for agricultural and industrial sectors. The results of the DSS make recommendations as to how to enhance long-term sustainability of water resources in Azraq, while allowing for water utilization and economic growth. It is recommended for future planning that further research of the impacts to water resources must be conducted at local and national levels and linked to regional and global climate change prediction. It can be concluded that the DSS tool and AHP are potentially positive contributions to the process of decision- making for selection and ranking of alternatives and policies and for help in solving problems that include conflicting criteria.  相似文献   
100.
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