高压变频器在罗茨鼓风机上应用的能效分析

本文着重介绍山东新风光JD-BP38-500F系列高压变频器在乌海黑猫炭黑有限责任公司AR系列罗茨鼓风机上的变频节能增效情况。结果表明,采用山东新风光JD-BP38-500F系列高压变频器对AR系列罗茨鼓风机进行调速节能,具有投资省、见效快等特点。     

A study of perceived air quality and sick building syndrome in a field environment chamber served by displacement ventilation system in the tropics

This paper presents a study of Perceived Air Quality (PAQ) and Sick Building Syndrome (SBS) using tropically acclimatized subjects in a Field Environmental Chamber (FEC) served by Displacement Ventilation (DV) system. The FEC, 11.12 m (L)×7.53 m (W)×2.60 m (H), simulates a typical office layout. A total of 60 subjects, 30 males and 30 females, were engaged in sedentary office work for 3 h. Air velocity in the space near the subjects was kept at below 0.2 m/s. Relative Humidity (RH) at 0.6 m height and outdoor air provision were maintained at 50% and 10 l/s/p, respectively. Subjects were exposed to three vertical air temperature gradients, nominally 1, 3 and 5 K/m, between 0.1 and 1.1 m heights and three room air temperatures 20, 23 and 26 °C at 0.6 m height. The main objective of this study is to evaluate the influence of temperature gradient and room air temperature (at 0.6 m height) on PAQ and SBS in DV environment. It was found that temperature gradient had insignificant impact on PAQ and SBS. Dry air sensation, irritations and air freshness decreased with increase of room air temperature.     

Assessment of thermal environment using a thermal manikin in a field environment chamber served by displacement ventilation system

This paper presents a thermal comfort study using a thermal manikin in a field environment chamber served by the Displacement Ventilation (DV) system. The manikin has a female body with 26 individually heated and controlled body segments. The manikin together with subjects was exposed to 3 levels of vertical air temperature gradients, nominally 1, 3 & 5 K/m, between 0.1 and 1.1 m heights at 3 room air temperatures of 20, 23 and 26 °C at 0.6 m height. Relative humidity at 0.6 m height and air velocity near the manikin and the subjects were maintained at 50% and less than 0.2 m/s, respectively. The aims of this study are to assess thermally non-uniform environment served by DV system using the manikin and correlate the subjective responses with measurements from the manikin. The main findings indicate that room air temperature had greater influence on overall and local thermal sensations and comfort than temperature gradient. Local thermal discomfort decreased with increase of room air temperature at overall thermally neutral state. The local discomfort was affected by overall thermal sensation and was lower at overall thermally neutral state than at overall cold and cool sensations.     

光伏逆变器的低电压穿越特性分析与参数测试方法

掌握逆变器的低电压穿越特性对于分析光伏电站对电网的影响具有重要的意义。首先基于光伏逆变器的拓扑结构和控制策略,将逆变器分为直流电压变换环节、交流电流指令环节和交流电流响应环节,分析了影响逆变器低电压穿越特性的主导关键环节。然后,提出了一种通用化的交流电流指令环节参数测试方法,依次辨识无功电流和有功电流指令公式参数,并代入仿真模型验证参数的准确性。最后,对主导关键环节的分析结论进行了试验验证,并验证了参数测试方法对组串式逆变器和集中式逆变器的适应性和有效性。     

城市出入口道路景观整治规划方法研究--以温州西进城口道路为例

城市出入口道路景观整治主要针对现状道路红线范围以内的道路景观,以及沿路两侧空间界面景观。温州西进城口道路景观整治规划提出以交通疏解、环境整治、形象塑造为主要手段,解决道路景观地域特色不明显等问题。     

Switching Vertical to Horizontal Graphene Growth Using Faraday Cage‐Assisted PECVD Approach for High‐Performance Transparent Heating Device

Plasma‐enhanced chemical vapor deposition (PECVD) is an applicable route to achieve low‐temperature growth of graphene, typically shaped like vertical nanowalls. However, for transparent electronic applications, the rich exposed edges and high specific surface area of vertical graphene (VG) nanowalls can enhance the carrier scattering and light absorption, resulting in high sheet resistance and low transmittance. Thus, the synthesis of laid‐down graphene (LG) is imperative. Here, a Faraday cage is designed to switch graphene growth in PECVD from the vertical to the horizontal direction by weakening ion bombardment and shielding electric field. Consequently, laid‐down graphene is synthesized on low‐softening‐point soda‐lime glass (6 cm × 10 cm) at ≈580 °C. This is hardly realized through the conventional PECVD or the thermal chemical vapor deposition methods with the necessity of high growth temperature (1000 °C–1600 °C). Laid‐down graphene glass has higher transparency, lower sheet resistance, and much improved macroscopic uniformity when compare to its vertical graphene counterpart and it performs better in transparent heating devices. This will inspire the next‐generation applications in low‐cost transparent electronics.     

基于Galois域的PLC离散分布控制系统容错配置设计

在机械制造业自动化领域,PLC分布控制系统的可靠性和容错性日益受到关注.在系统的容错性设计中,将每个可编程控制器作为一个控制结点,结点之间通过网络进行连接保持通信;通过增加一个冗余控制器,使系统能够自动侦查各结点的工作状况;并且通过在Galois域运行相关算法使不能正常工作的结点的功能得到恢复,保证系统的正常运行,提高其可靠性.实验证明这种设计是有效可行的.     

侧流免疫层析技术在食品安全检测中的研究进展

侧流免疫层析技术(lateral flow immunoassay,LFIA)不仅有效结合了层析技术的分离能力和免疫分析的高度特异性,而且操作简单、检测快速、价格低廉,为食品安全现场检测提供了一种理想的技术平台。常规的LFIA主要以纳米金颗粒作为信号标记材料,该种方法检测灵敏度相对较低,仅能满足定性和半定量检测。为了提高LFIA的检测性能,近年来研究者做了大量的努力。本文总结了LFIA的检测原理及其在在信号标记材料、信号增强方式、多元分析物同时检测、信号读出方式等方面的技术改进,并讨论了LFIA现有的不足以及未来的发展方向,以期为我国食品安全快速检测的发展提供技术参考。     

Does how you quit affect success? A comparison between abrupt and gradual methods using data from the International Tobacco Control Policy Evaluation Study.

Two recommended quit methods in standard cessation programs involve either gradual reduction of smoking prior to complete abstinence ("cut down") or abrupt abstinence from cigarettes ("cold turkey"). This study examined the reported use, characteristics of users, and the impact of self-selected strategy choice on quitting success and relapse of adult smokers who reported quitting on their own. Data came from the first three waves of the International Tobacco Control Policy Evaluation 4-Country Survey (ITC-4). The ITC-4 is a random-digit-dialed telephone survey of a cohort of more than 8,000 adult smokers from the United Kingdom, the United States, Canada, and Australia, with a 75% follow-up rate. The results indicated that 68.5% of the smokers who had made a quit attempt between waves reported using the cold-turkey method. Of those who used the cold turkey method, 22% and 27% succeeded at Waves 2 and 3, respectively, compared with the 12% and 16%, respectively, who used the cut-down method. Multivariate analyses revealed that cold-turkey users were more likely to be aged 25-39 years, male, from the United Kingdom, and smoking heavily, and had lower perceived dependence. Controlling for sociodemographic and known predictors of quitting including use of medications, we found that smokers who used the cold-turkey method to quit were almost twice as likely to abstain for a month or more in their attempt. Overall, we cautiously conclude that cold turkey should be the recommended strategy for smokers who want to quit on their own.