排序方式: 共有28条查询结果,搜索用时 359 毫秒
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新型DAT系列配电自动化终端 总被引:2,自引:2,他引:0
通过分析国内配电自动化系统的现状,介绍了一种适合我国配电网国情的DAT系列配电自动化终端设备。在终端设备设计时考虑了双CPU、统一硬件平台、通信标准化等主要设计思想,同时采用了电子设计自动化(EDA)和“黑匣子”等先进技术,并在同杆架设、蓄电池维护等多方面具有创新之处。 相似文献
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DAT-IAT工艺是在满足连续进水的情况下,将连续曝气池DAT与间歇曝气池IAT串联而成的一种新的污水处理工艺方法。本研究以DAT-IAT工艺为基础,在DAT-IAT池进水处设置一厌氧生物选择器增强其除磷功能,以影响厌氧选择器生物除磷最为重要的三个操作参数为试验变量,即回流比、生物选择器体积比(R)以及进水易生物降解COD,研究厌氧生物选择器厌氧除磷的规律。 相似文献
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The problem of tuning single‐loop controllers in heating, ventilating and air conditioning (HVAC) systems is explored. The HVAC process was described by a first‐order‐plus‐dead‐time (FOPDT) model. By using recursive least squares method, the model parameters were updated while the system remained in closed‐loop. The H∞ loop‐shaping tuning rules published in the literature were transformed to discrete‐time tuning rules and were implemented in an adaptive PI control strategy. The methodology was applied to a discharge air temperature (DAT) control system. The output responses of adaptive PI controller were compared with a LQR optimal adaptive controller. Simulation results show that the adaptively tuned PI controller is able to track setpoint changes very well in the presence of changes in plant parameters, disturbances and external noise acting on the system. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Gizer Ian R.; Waldman Irwin D.; Abramowitz Ann; Barr Cathy L.; Feng Yu; Wigg Karen G.; Misener Virginia L.; Rowe David C. 《Canadian Metallurgical Quarterly》2008,117(4):869
Researchers conducting candidate gene studies of attention-deficit/hyperactivity disorder (ADHD) typically obtain symptom ratings from multiple informants (i.e., mothers, fathers, and teachers) and use a psychologist's best estimate or a simple algorithm, such as taking the highest symptom ratings across informants, to construct diagnostic phenotypes for estimating association. Nonetheless, these methods have never been empirically validated in the context of a molecular genetic study. In the current study, the authors systematically evaluated several methods of operationalizing phenotypes and the resulting evidence for association between ADHD and the candidate genes: dopamine transporter gene (DAT1) and dopamine D4 receptor gene (DRD4). Use of symptom scores as continuous scales in regression analysis suggested that the combination of mother and teacher ratings yielded the strongest evidence for association between hyperactive-impulsive ADHD symptoms and DAT1 and between inattentive ADHD symptoms and DRD4. Teacher ratings alone were sufficient for evaluating the association between inattentive symptoms and DAT1. Further, this regression-based method consistently yielded stronger evidence for association among ADHD symptoms, DAT1, and DRD4 than did three simple algorithms (i.e., the and, or, and averaging rules). The implications of these results for future molecular genetic studies of ADHD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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广播节目录制经验点滴--记广播剧《六千万分之一》的录制 总被引:1,自引:0,他引:1
本文讲述了广播剧《六十万分之一》的录制过程,从以下三个方面探讨了如何提高广播节目录制质量:前期录音,合理利用音频工作站,磁带转录的技巧。 相似文献
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应用SPECT分子影像技术在生理状态下可视化研究氯胺酮依赖的脑内损害靶点。随机选择20例来北京大学深圳医院门诊就诊的氯胺酮依赖患者,随机有偿招募的31例健康志愿者为对照组,分别对其行SPECT DAT显像。由专业医师对上述患者的显像结果进行定性及定量分析,计算氯胺酮依赖患者和健康志愿者纹状体的体积、质量和纹状体与全脑放射性比值(Ra)。所得结果采用SPSS 16.0软件进行t检验分析。健康志愿者对照组双侧纹状体外形饱满、等大,放射性分布均匀对称,呈"熊猫眼"形态;氯胺酮依赖组双侧纹状体明显变小,外形呈多种形态改变,双侧纹状体DAT的分布、结合位点、数量和活性下降;同时脑内放射性分布紊乱,非特异摄取明显增多。双侧纹状体体积为(21.03±3.15)cm~3、质量为(22.08±3.31)g、Ra=(5.37±1.08)%,均低于健康对照组(p0.01)。氯胺酮依赖的脑内损害靶点与复方磷酸可待因止咳水、海洛因及摇头丸依赖类似,使脑内纹状体区DAT的功能受损。结果表明,脑内纹状体区域DAT为精神活性物质滥用作用的主要靶点。 相似文献
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用密度泛函方法,计算研究1,5-二氨基四唑(DAT)的电子结构及异构化反应机理。在B3LYP/6-311G水平下,对涉及反应各驻点的几何结构、振动频率、自然键轨道、以及零点能( ZPE)进行了计算;用内禀反应坐标理论( IRC)获得反应的最小能量路径(MEP),在耦合簇理论的CCSD(T)方法下计算单点能得到了反应的最小势能曲线;并且用传统过渡态理论(TST)、Eckart 隧道校正理论(TST/Eckart)和变分过渡态理论(CVT),计算了200~1000 K的反应速率常数。计算结果表明,DAT分子中的N(4)和N(9)易参与金属原子配位,形成一系列以DAT为配体的配位化合物。异构化合成DAT反应为叠氮基关环机理,气态情况下该反应为放热且自发反应,反应活化能较低。 相似文献
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以需氧池-间歇曝气池(DAT-IAT)工艺为基础,在其后设置一生物接触氧化反应器,考察了该组合工艺对生活污水中氨氮的去除效果。结果表明,在IAT池以曝气2h、沉淀1h、出水1h的工况运行及生物接触氧化反应器的HRT为3h的条件下,系统对氨氮的平均去除率为81.1%,出水氨氮平均浓度为7.0mg/L,满足《城市污水再生利用城市杂用水水质》(GB/T 18920-2002)的要求。系统对氨氮的去除率随着进水COD浓度的提高而下降,当进水COD为815.3mg/L时,出水氨氮浓度仍可满足GB/T 18920-2002的要求;随着进水氨氮浓度的提高,系统对氨氮的去除率先略有上升后明显下降,为保证出水氨氮浓度达到回用标准,应将进水氨氮浓度控制在50mg/L以下;系统适宜的pH值范围为7~8,pH值过高或过低都会造成系统对氨氮去除率的显著下降。 相似文献
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