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991.
感知觉信息处理的定性映射研究   总被引:1,自引:0,他引:1  
感知觉信息处理是心理学、神经科学、人工智能等领域一个重要的研究方向。建立视觉、听觉以及其他相关感觉方面的信息处理的生物原型和数学模型,涉及脑工作机制的揭示;另一方面,感知觉的产品开发蕴涵着巨大的经济、军事价值。研究了初级听皮层对声音信息的处理。运用定性映射的方法,描述了皮层中特定的功能柱对特定的声音属性进行反应这种感知觉信息处理的普遍现象。  相似文献   
992.
To lower the fabrication cost of silicon solar cells, a surface treatment using a dielectric barrier discharge (DBD) instead of a wet cleaning technique was examined on electrode surfaces on silicon solar cells. The fill factor obtained through measuring current–voltage characteristics was evaluated, and the treated surface state was characterized by energy-dispersive X-ray. It was found that the DBD effectively activated the electrode surface and the surface treatment on finger electrodes contributed greatly to improve the fill factor.  相似文献   
993.
吴江市高等职业技术学院报告厅是一个椭圆形的平面,针对可能出现的声聚焦问题,声学设计中提出的技术处理方法是有效的,现场测量和主观调查表明声学设计取得了满意的音质效果。  相似文献   
994.
This paper reviews recent efforts by authors’ group to utilize electrochemical processes for formation, processing and gate control of III-V semiconductor nanostructures. Topics include precise photo-anodic and pulsed anodic etching of InP, formation of arrays of 〈0 0 1〉-oriented straight nanopores in n-type (0 0 1)InP by anodization and their possible applications and macroscopic and nanometer-scale metal contact formation on GaAs, InP and GaN by a pulsed in situ electrochemical process, which remarkably reduces Fermi level pinning. All the results indicate that electrochemical processes can achieve unique and important results, which the conventional semiconductor technology cannot realize, anticipating their increased importance in future semiconductor nanotechnology and nanoelectronics.  相似文献   
995.
飞机舱室内噪声的预测对改进飞机性能具有重要意义,并为实际飞机设计和噪声控制措施提供理论依据。文章建立了飞机壁板隔声的统计能量分析模型,研究了外部声场激励和振动激励通过飞机壁板的隔声量,预测了飞机舱室内的声场分布。在此基础上运用面向对象及可视化技术,开发出相应的专用软件,该软件界面友好,用户可根据需要选定结构参数,材料性能,更改外部激励,并对预测结果进行可视化处理。运用该软件对舱内噪声进行预测,可以缩短飞机设计周期,减小对已有结构进行噪声控制的困难,提高经济效益。文中通过对某型飞机的舱室内噪声进行预测,验证了统计能量法预测飞机壁板隔声量的可靠性和该软件的实用性。  相似文献   
996.
In this paper, we study the impact a heat source makes on the thermo-hydraulic behaviour of a system composed of an engineered clay barrier and a host rock, namely an argillite. We first perform a benchmark test case with code CAST3M and code ASTER. The results of the calculations are in good agreement, except for the gas pressure. Nevertheless, gas pressure does not seem to influence the saturation process, although the saturation kinetics is governed by the darcean water flow. The saturation process is accelerated when the heat source is taken into account. More precisely, this acceleration is due to dynamic viscosity increase with heating. In a second time, five other heating sources have been tested in code ASTER. Compared with the reference calculations, some give an identical response. However, the highest heating sources provoke a desaturation phenomenon because of the air pressure increase with temperature. The liquid saturation of the engineered barrier is then delayed.  相似文献   
997.
ACOUSTIC ENVELOPE DETECTOR FOR CRISPNESS ASSESSMENT OF BISCUITS   总被引:2,自引:0,他引:2  
The crispness of food materials based on the force/displacement behavior and their acoustic nature was assessed using an Acoustic Envelope Detector (AED) attached to the Texture Analyzer, wherein six kinds of biscuits were used: Carr's Table Water, Crackerbread, Digestive, Dutch Crispbakes, Rich Tea fingers and Shortbread. The force/displacement and acoustic signals were simultaneously recorded during the breakup of biscuits. For each detected acoustic signal, there was a sudden drop in the compression force. The analysis of the force/displacement curve demonstrated the links between the second derivative of force curve and the acoustic event, indicating the energy released through the air of these crack events. The acoustic behavior of the biscuits was assessed in terms of maximum sound pressure level and the number of acoustic events, which were further interpreted as the acoustic events per unit area of newly created surface area and the acoustic event per unit time. The acoustic ranking of biscuits from instrumental assessment was in very good agreement with that from sensory panel tests. The normal integration time (1.25 ms) for the AED was generally effective in detecting acoustic signals for crisp biscuits, but a shorter integration time (0.25 ms) was found advantageous in detecting acoustic signals that occur within a very short time period and gave better differentiation of crisp biscuits.  相似文献   
998.
Au/n-GaN Schottky diodes with the Au electrode deposited at low temperature (LT=77K) have been studied. In comparison, the same chip of GaN epitaxial layer was also used for room temperature Schottky diodes. The low temperature Schottky diodes exhibit excellent performance. Leakage current density as low as 2.55×10−11 A·cm−2 at −2.5 V was obtained in the LT Schottky diodes. The linear region in the current-voltage curve at forward bias extends more than eight orders in current magnitude. Current-voltage-temperature measurements were carried out to study the characteristics of the LT Schottky diodes. A typical barrier height of about 1.32 eV for the LT diode, which is the highest value ever reported, was obtained. The obvious enhancement in electrical performance makes the LT processing a very promising technique for GaN device application although the detailed mechanisms for the LT Au/n-GaN Schottky diodes are still under investigation.  相似文献   
999.
电流变液夹层圆柱壳声振性能实验研究   总被引:4,自引:3,他引:1  
本文选用自行配制的硅油基纳米硅粉和淀粉电流变液 (ERF) ,对灌注电流变液的夹层圆柱壳体的隔声性能及声激励结构响应进行了实验研究 ,对不同电流变液在外加电场下的流变现象进行了定性分析和比较 ,分析了外加电场对电流变液夹层圆柱壳体的声和振动的控制效果。实验结果表明 :施加电场后的电流变液夹层圆柱壳体对处于中、高频率的声波没有明显的吸收和阻隔效果 ,但对于由声激励引起的结构振动有明显的控制作用。无论对声传播还是声激振动 ,电流变材料的影响都是随频率变化而变化的。  相似文献   
1000.
通过求解Poisson方程,对热平衡态金属:p-n-CdTeSchotky势垒薄膜太阳能电池进行计算机数值模拟。嵌入的p型层增大传统金属:n-CdTe结的有效Schotky势垒高度与p型层厚度、掺杂浓度以及n-CdTe本底电阻率有依赖关系。最后讨论嵌入p型层增强CdTeSchotky势垒太阳能电池对光生载流子的收集作用。  相似文献   
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