共查询到20条相似文献,搜索用时 265 毫秒
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照明对人体褪黑素分泌产生影响 ,从而影响不同年龄人的睡眠质量 ;适当的照明可以起到调节人体生物节律的作用 ,通过改善照明状况可以调节由于季节变化引起人体接受光照不足而产生的季节性情绪紊乱 (SAD) ;不同照度、不同色温的照明光环境对不同年龄、不同性别的人群所产生的舒适感也存在着差异。 相似文献
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照明对人体褪黑素分泌产生影响,从而影响不同年龄人的睡眠质量;适当的照明可以起到调节人体生物节律的作用,通过改善照明状况可以调节由于季节变化引起人体接受光照不足而产生的季节性情绪紊乱(SAD);不同照度、不同色温的照明光环境对不同年龄、不同性别的人群所产生的舒适感也存在着差异。 相似文献
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照明对人的生理与心理的影响 总被引:1,自引:1,他引:1
照明对人体褪黑素分泌产生影响,从而影响不同年龄人的睡眠质量,适当的照明可以起到调节人体生物节律的作用,通过改善照明状况可以调节由于季节变化引起人体接受光照不足而产生的季节性情绪紊乱(SAD0,不同照度,不同色温的照明光环境对不同年龄,不同性别的人群所产生的舒适感也存在着差异。 相似文献
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It is important to investigate impurity scattering phenomena when modeling graphene nanoscale devices, as impurities are invariably present in any realistic system and can significantly influence graphene carrier transport. We present a short review of quantum transport where density functional theory (DFT) is carried out within the nonequilibrium Green’s function formalism (NEGF), focusing on a recent extension of this framework in the form of nonequilibrium vertex correction (NVC) that captures random graphene impurity scattering in a systematic fashion. Our results show that disorder effects significantly alters the electronic and transport properties of graphene devices. We argue that disorder effects should not be ignored if one were to model graphene nanoscale devices in realistic situations, including arriving at fundamental electronic properties such as Ohm’s law. 相似文献
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本研究根据“安全视距法”,利用先进的眼动仪系统,通过对多条隧道入口段的现场实验,创新性地总结出一种全新的隧道入口段照明质量检测方法.该方法可直接测取驾驶人员在驾车进入隧道过程中的视觉功效,由此评价隧道入口段的照明质量,它是驾驶人员生理和心理效应的客观反映,弥补了常规照明检测方法(如路面亮度或照度的检测)难以反映人们生理和心理效应所带来的缺陷.文中对研究依据、测试设备、实验条件、实验及数据处理方法进行了详细介绍,并根据数据处理结果,对照明质量进行了分析和评价.该方法的成功运用,将对提高隧道照明设计标准的合理及科学性,具有重要的意义. 相似文献
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This paper analyses time series without the seasonal component of consumers’ power consumption at low voltage in order to detect fraud and illogical consumption by customers. Statistical process control is used, where the process represents the process of using electricity. XMR charts are used to indicate major changes (decrease) in registered customers’ consumption. Verification of this method was tested on time series of a set of customers who were caught stealing during a time series. It shows that symptoms of non-random factors in time series of customers are revealed in a high percentage, which indirectly confirms the method’s ability to successfully detect electricity fraud. 相似文献
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中长期运行是电力能源系统运行的重要内容,能有效应对能源供应的季节性矛盾。针对电力、天然气等多种形式能源间耦合性不断增强的趋势,提出一种面向多能源系统的中长期运行模型和方法。考虑可再生能源的季节特性、天然气价格的波动情况,计及系统运行约束以周为时间单位构建多能源系统运行模型,对年度的发电机组检修计划、水电电量分配和天然气的购买及贮存计划进行统一优化。以修改的IEEERTS79系统为算例,分析验证所提模型与方法的正确性、有效性。算例结果表明,统筹安排多能源系统的中长期运行能发挥不同能源形式的互补效益,提升系统的运行经济性;引入储气装置能缓解冬季供气紧张现象,降低系统的运行成本。 相似文献
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阶梯波合成逆变器的波形调制技术研究 总被引:1,自引:0,他引:1
阶梯波合成逆变器开关频率低,谐波含量小,滤波容易,特别适合大功率应用场合,但由于传统阶梯波合成逆变器功率管驱动信号采用延时的方法产生,动态性能差。研究了一种新的阶梯波合成逆变器波形调制技术,采用空间矢量调制方法得到各桥功率管驱动信号,提高逆变器的带宽。在分析移相变压器对空间矢量的影响的基础上,结合阶梯波合成逆变器对驱动信号的逻辑要求,提出从相位滞后通道至相位超前通道顺序采样的错时采样空间矢量调制(space vector modulation,SVM)策略,并分析该调制技术的谐波消除机制和特性。仿真和实验验证了该技术可以用于阶梯波合成逆变器的输出电压的调节,具有优良的输出频谱特性,且增大了逆变器的带宽,有利于提高逆变器的动态性能。 相似文献
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A. D. Klyuchnikov 《Thermal Engineering》2006,53(11):930-935
A fundamental drawback of the traditional block diagram of power engineering is shown, one due to which people analyzing the efficiency of the country’s power facility have no choice but use an energy utilization factor overestimated by several times. The need to correct this scheme is substantiated: the area of the end use of energy is singled out and is given the status of a new field of power engineering and, logically, is called the “power engineering of a technology.” 相似文献
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Noah Dormady 《The Electricity Journal》2017,30(5):42-46
Ohio’s recent experience with three multi-billion-dollar power purchase agreement cases raises new questions about the role of public utility commissions in deregulated markets. The PPA proposals would have effectively re-regulated utility’s generation businesses, guaranteeing returns on their generation units operating in a deregulated market. This article provides a concise summary of the core arguments of proponents, and analyzes the adverse effects of the proposals on both wholesale and retail electricity markets. 相似文献