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1.
《Current Applied Physics》2020,20(4):582-588
Energy storage system powered by renewable energies is a viable option to meet energy requirement without addition of carbon footprints to the environment. This study involves development of theoretical and computational models for a solar photovoltaic (PV) system coupled with a lead acid battery. The study commenced with selection of most appropriate lead acid battery and PV system for installation in a representative location in Riyadh, Kingdom of Saudi Arabia. Various technical and economic parameters were assessed and calculated by computational approach. The optimized lead acid battery was integrated with low concentration solar PV panels (CPV) followed by a feasibility study. Theoretical model was developed for the integrated system to calculate various parameters of the CPV and lead acid battery. Technical and economic assessment of this coupled unit was calculated using a theoretical approach. The developed model was then subjected to computational approach for verification and validation analysis of the integrated system. The detailed assessment of batteries and integrated system show the applicability of this system in Riyadh region. The research will be extended to develop energy storage systems for remote areas using lead acid batteries. 相似文献
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We theoretically investigate optomechanical force sensing via precooling and quantum noise cancellation in two coupled cavity optomechanical systems.We show that force sensing based on the reduction of noise can be used to dramatically enhance the force sensing and that the precooling process can eifectively improve the quantum noise cancellation.Specifically,we examine the effect of optomechanical cooling and noise reduction on the spectral density of the noise of the force measurement;these processes can significantly enhance the performance of optomechanical force sensing,and setting up the system in the resolved sideband regime can lead to an optimization of the cooling processes in a hybrid system.Such a scheme serves as a promising platform for quantum back-action-evading measurements of the motion and a framework for an optomechanical force sensor. 相似文献
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Hong-Tao Lin Ying-Xin Ma Song Chen Prof. Xue-Dong Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202214214
The combination of multiple components or structures into integrated micro/nanostructures for practical application has been pursued for many years. Herein, a series of hierarchical organic microwires with branch, core/shell (C/S), and branch C/S structures are successfully constructed based on organic charge transfer (CT) cocrystals with structural similarity and physicochemical tunability. By regulating the intermolecular CT interaction, single microwires and branch microstructures can be integrated into the C/S and branch C/S structures, respectively. Significantly, the integrated branch C/S microwires, with multicolor waveguide behavior and branch structure multichannel waveguide output characteristics, can function as an optical logic gate with multiple encoding features. This work provides useful insights for creating completely new types of organic microstructures for integrated optoelectronics. 相似文献
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分子筛和金属有机骨架(MOF)材料以其独特的孔道和骨架结构在催化、 储能、 干燥及净化和吸附分离等领域有着广泛应用, 对其结构的原子尺度表征对于深入理解其构效关系具有重要意义. 但其大孔道结构和有机骨架使得它们对电子束辐照极为敏感, 在常规透射电镜成像模式下结构会很快被破坏变为非晶, 从而无法获得孔道和骨架的原子排列信息. 最近发展起来的基于积分差分相位衬度扫描透射电子显微(iDPC-STEM)技术在电子敏感材料和轻元素组分成像方面展现出明显优势, 使得对多孔骨架材料及烃池物种的表征成为了可能. 本文综述了本课题组近期利用该技术对分子筛和MOF材料原子尺度结构方面的研究. 将iDPC-STEM技术应用到ZSM-5分子筛催化剂中, 实现了对该分子筛的原子级骨架结构的成像分析. 在MOF体系中, 利用该技术观察到MIL-101骨架内部有机连接体与金属节点的配位方式, 在此基础上解析了MIL-101结构中有机配体的连接和金属节点的苯环结构, 并观察了MOF的原子级表面、 界面和缺陷等局域结构特征. 最后对iDPC-STEM技术在原子尺度成像方面的应用潜力进行了总结与展望. 相似文献
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In active sound control, noise shielding of a target region is achieved via additional sources (called controls) situated at the perimeter of the region. The sources protect the target region by adjusting the acoustic field near the boundary of the region. In the present paper a numerical model of active sound control based on surface potentials in 3D bounded composite regions is numerically studied. In the composite region setup, it is required that the regions be shielded from noise while allowing admissible sound that is generated in the shielded regions to be preserved. The admissible sound is usually required to propagate freely inside the protected regions or in a (selective) predetermined pattern. The adjusting approach used here does not require any knowledge of the sound sources or the properties of the propagation medium in order to obtain the controls. Moreover, the approach differs sharply from some other approaches where the detailed knowledge of the sound sources and the propagation medium is required. For the first time, numerical test cases involving both free communication and predetermined communication pattern between the regions in three dimensions are considered. In all test cases, these regions are effectively shielded from the noise while any present admissible sound is preserved. In addition, selective propagation of the admissible sound between the regions is enforced. The effect of the number of controls on their operation is also studied. Whether admissible sound is present or not, the level of noise cancellation decreases linearly as fewer controls are used. In addition to the increase in size of the interference zone, the controls become individually distinguishable. 相似文献
7.
When constructing Bayesian networks with domain experts, network engineers often use the noisy-OR model, and causal interaction models more generally, to alleviate the burden of probability elicitation: the use of such a model serves to reduce the number of probabilities to be elicited on the one hand, and on the other hand forestalls experts having to give assessments for probabilities with compound conditions which they feel are hard to envision. Recently, we have shown that ill-considered use of the noisy-OR model specifically can substantially decrease a network's performance, especially in domains in which causal mechanisms include cancellation effects. Motivated by this observation, we designed a new causal interaction model, with the same engineering advantages as the noisy-OR model, to describe such effects. We detail properties of our intercausal cancellation model, and compare it against existing causal interaction models. We further illustrate the application of our model in the real-world domain of pharmacology. 相似文献
8.
In practical applications, information about the accuracy or ‘fidelity’ of alternative surrogate systems may be ambiguous and difficult to determine. To address this problem, we propose to treat surrogate system fidelity level as a categorical factor in optimal response surface design. To design the associated experiments, we apply the Expected Integrated Mean Squared Error optimal design criterion, which takes into account both variance and bias errors. The performance of the proposed design was compared using three test cases to four types of alternatives using the Empirical Integrated Squared Error. Because of its ability to foster relatively accurate predictions, the proposed design is recommended in fidelity experimental design, particularly when the experimenters lack sufficient information about the fidelity levels of surrogate systems. The method was applied to the case of intraday trading optimization in which data were collected from the Taiwan Futures Exchange. We also calculated the implied volatility from the Merton's Jump‐diffusion model via the fast Fourier transform algorithm with three different models of varying fidelity levels. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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10.
随着集成电路的集成度与性能的不断发展,芯片的功耗问题已经变的十分严重,功耗带来的挑战日益突出。异构多核动态调频架构是目前研究低功耗的主流方向。SOC系统当中同一时刻只有一个处理器能够控制总线,其它处理器则处理等待状态,异构多核动态调频架构能够通过降低不控制总线的处理器频率来达到降低功耗的目的。异构多核领域的处理器和总线跨时钟域解决方案,此方案在国内属于首次提出,可以运用在异构多核动态调频(DFS)架构当中。目前手持终端设备越来越强调功耗的重要性,因此异构多核领域的处理器和总线跨时钟域解决方案将有非常好的应用前景。该方案通过在处理器和AMBA总线之间添加FIFO以及一些复杂的算法,达到消除亚稳态和正常通信的目的。最终,通过仿真发现任意调节处理器的工作频率都能满足传输协议。证明该方案能在异构多核动态调频架构中运用。 相似文献