共查询到20条相似文献,搜索用时 93 毫秒
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文章介绍了一种简易的VAV(Variable Air Volume)空调系统,此 房间温度控制采用数字式温控器结合风阀执行器来实现,空调送风机采用变频控制,固定新风量比,保证新风量在设定范围之内,实现运行证明与常规的VAV空调系统比较,这种系统不但初投资小,而且筒易可行,是一种较好的空调节能系统。 相似文献
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鉴于单片机测量法测量振弦式传感器共振频率具有抗干扰能力强、功耗低、信号采集精度高等优点,利用单片机做中央处理单元,采集器采用脉冲激励的方法,使振弦式传感器产生共振,再将共振信号经放大器和滤波器输入到单片机,由单片机处理后转换成数字信号,并将其应用于武汉市道观河水库溢洪坝内。结果表明,该系统不仅提高了整个系统的抗干扰能力,且适应性强、可靠性高、便于安装和埋设。 相似文献
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本文以8098单片机为基础,附加少量硬件组成系统,阐述了变频调速PWM波形产生方法;讨论了单片机实时产生PWM波形的基本原理和指导思想;介绍了8098单片机组成的控制系统的硬件结构和软件框图。 相似文献
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30kW风—光联合电站光电控制器 总被引:1,自引:0,他引:1
本文介绍了一种用于大中型光电系统、由单片机做核心的无触点控制器,着重探讨了在使用单片机情况下控制软件的设计思路和方法。该控制器目前已实用于现场,取得良好效果。 相似文献
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通过哈尔滨泛亚食品机械有限公司(原哈尔滨酿造食品机械厂)多年来在研制开发酿造食品机械、豆制品加工机械的过程中,坚持按照市场需求创新、坚持技术工艺创新、坚持按照“三化”原则创新的实践,研制开发各种类型的豆制品加工机械,特别是外形美观、功能齐全、性能优良、操作方便的豆腐系列加工机械和豆腐生产设备机械化自动控制的做法和体会。 相似文献
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分析了农村环境的污染现状,指出了造成农村环境污染的几个主要原因,并根据中国农村发展规划,提出了相应的对策和保障措施。 相似文献
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实际运行中,存在空冷凝汽器局部翅片表面温度低于大气环境温度的现象,运用管道内绝热流动的简化能量方程不能客观地解释此现象;经分析,指出此现象是温度测点显示环境冷空气干球温度下的湿球温度值所致。不凝气体的聚积是空冷凝汽器管束冬季结冻的主要原因之一,由此,针对防冻工作提出相关建议。 相似文献
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叶栅流场中的叶片受流道中汽流力的作用,同时也承受了流道中谐波汽流力的激振。由于谐波汽流力沿周向波动,其对叶片的激振力应该是流道宽度内谐波激振力的积分。本着这一观念对ASME早期发表的动应力基本方程进行改进,重新作了推导,并指出了降低叶片共振应力的途径。多年来已取得了成功应用,其中涉及带冠单叶片的动强度特性及不调频叶片事故处理的材料综合抗振强度对比分析,对工程实践具有一定的参考借鉴的价值。 相似文献
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《Energy Policy》2016
This paper aims at reassessing the empirical relationship between the real price of oil and the U.S. dollar real effective exchange rate over the 1974–2015 period. We find that changes in both variables are now linked by a negative relationship, going from the dollar exchange rate to the real oil price. However, the same relationship is found positive when ending the sample in the mid-2000s, in line with the previous literature. To understand and investigate this evolution, we rely on a nonlinear, smooth transition regression model in which the oil price-dollar nexus depends on the dynamics followed by the U.S. currency. Our results show that the relationship is negative most of the times but turns positive when the dollar hits very high values, as in the early eighties. 相似文献
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We study cointegration and causality between the real price of oil and the real price of the dollar over the 1974–2004 period. Our results suggest that a 10% rise in the oil price coincides with a 4.3% appreciation of the dollar in the long run, and that the causality runs from oil to the dollar. Through the development of a theoretical model, we then investigate possible reasons why this relationship could be reversed in the future due to the emergence of China as a major player on both the oil and the foreign exchange markets. 相似文献
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以长江中下游地区一办公建筑为例,通过对采用氨水溶液的蓄能制冷与压缩制冷复合循环系统在分量蓄能策略下的工作过程进行数值模拟,得到复合循环系统工作参数和特性的变化规律。研究结果表明在分量蓄能策略下采用复合系统可以获得更佳的效果。 相似文献
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Photovoltaic devices based on poly-2′,5′-dioctyl-4,4′′-terphenylenecyanovinylene (J-domain) and 4-aza-4-(4′-(poly-2′,5′-dioctyl-4,4′′-terphenylene-1-cyanovinylene-2-yl)biphen-4-yl)-8,12-dioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrenium tetrafluoroborate (JA-assembly) were prepared using indiumtinoxide (ITO) as the transparent electrode and aluminium as the second electrode. While the photovoltaic response of the J-domain exhibited low short circuit currents of −0.1 nA cm−2, the corresponding short circuit current of the JA-assembly was observed to be +10 nA cm−2. The 100-fold increase in magnitude was related to the known energy transfer from the J-domain to the A-domain in the JA-assembly, and the inversion of the sign of the photovoltaic response that implies that the electrodes have a reversed polarity was explained on the basis of the positions of the energy levels and involves the action of the A-domain as a blocking layer and a light operated charge pump that efficiently transfers electrons to the ITO electrode. 相似文献