DS18S20在单总线多点测温系统中的应用技巧

DS18S2 0是一种新型的单总线数字温度传感器。该器件在实际应用中 ,如果使用不当不但无法发挥其优势 ,反而会引入不必要的误差 ,文章重点阐述了它的使用技巧和方法     

基于EWB的D/A数模转换器的仿真研究

阐述了D／A转换器的仿真原理，给出了T形电阻网络D／A转换器仿真模型的构造方法，并采用EWB进行了系统仿真，仿真结果表明该方法是合理、可行的。     

Comparative study of the elimination of toluene vapours in twin biotrickling filters using two microorganisms Bacillus cereus S1 and S2

BACKGROUND: To investigate the microbial degradation performance of organic pollutants in the atmosphere using a biotrickling filter, two microorganism strains, Bacillus cereus S1 and Bacillus cereus S2, were selected, identified and inoculated into a twin biotrickling filter for comparison. RESULTS: Both strains showed good performance towards the degradation of model organic pollutants when gas flow rates ranged from 100 to 600 L h⁻¹. For S1, the total maximum removal efficiency (RE) of toluene was maintained nearly 100% not only at gas flow rates of 100 L h⁻¹ corresponding to empty bed residence time (EBRT) 199.44 s, but also at gas flow rates of 200 L h⁻¹ (EBRT = 99.72 s) and 300 L h⁻¹ (EBRT = 66.48 s). However, S2 had a much lower degradation capability; near 100% removal efficiency was obtained only at the gas flow rate of 100 L h⁻¹ although both bacteria belong to the same Bacillus cereus. With further increase in gas flow rate, the total REs for both S1 and S2 decreased slightly at first and then dropped sharply to 46% and 35%, respectively, at an EBRT of 33.24 s, corresponding to a gas flow rate of 600 L h⁻¹. Starvation for between 2 and 10 days resulted in the re‐acclimation times of both strains ranging between 1.0 and 15.5 h. CONCLUSION: Strain S1 would be a better choice for inoculation into a biotrickling filter than strain S2, because of its much higher toluene removal capacity and rapid recovery to full performance. Copyright © 2008 Society of Chemical Industry     

单相负载三相供电功率分配之PLC改造实践

介绍了单相负载一工频感应炉供电的S7-200CPU224改造实践方案.依托原有设备条件,三相功率分配同样设计采用电容、电抗进行调节,起、停及三相电流平衡控制由晶闸管 接触器形式替代原单纯采用接触器控制,有效值测量使用有别于FFT的检测算法.运行实践表明:节能降耗明显,设备故障率大幅降低,具有良好的推广应用价值.     

PbS-Sb2S3-FeS三元系在水蒸气气氛下的铅锑分离

在1073K下通过测定三硫化锑和硫化铅的挥发速度,研究了PbS-Sb_2S_3-FeS三元系在水蒸气气氛下的铅锑分离规律。X-射线衍射结果表明,焙砂由PbS、Fe_3O_4、FePb_4Sb_6S_(14)、Pb_5Sb_4S_(11)和FeSb_2O_4组成。当试样中FeS含量在5％～7％时,铅锑分离效果最好。当试样中FeS的含量≥10％时,铅锑分离效果较差,这时过量的FeS会与Sb_2S_3和PbS形成复杂的硫化物(FePb_4Sb_6S_(14)、Pb_5Sb_4S_(11))或被氧化成F4Sb_2O_4,使锑的挥发变得困难,导致残留在焙砂中的锑含量升高。     

基于S2A6000存储的新闻制播网络安全设计

从分析S2A6000新闻制播网系统特点,拓扑结构入手,完整总结了S2A6000存储的新闻制播网络安全设计与安全措施。     

T梁预制中需要注意的问题

为确保在T梁预制时 ,其内、外的质量和安全施工 ,介绍了四个需特别注意的问题。指出在T梁预制时 ,应把质量放在首位 ,进行具体、综合的分析和计算     

What Did Freud Say About Persons and Relations?

History is bunk, declared Henry Ford; he wanted to sell new cars every year. For psychoanalysis history is not bunk; it is its very heart and guts. Like an individual or a nation, psychoanalysis lives its history and rediscovers it in every generation. Psychoanalytic pioneers, authors of new rallying cries and new theories, seem to think otherwise: History of psychoanalysis begins with them. The author suggests a different approach: to see the new as a historical continuity of the old. The advocates of the relational approach in psychoanalysis will be surprised to hear that Freud was a Sullivanian, even though--like the proverbial M. Jourdain who never heard the word prose--he never heard of the word interpersonal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于B/S模式的电力企业指标管理信息系统的分析和设计

本文介绍了使用原型化系统开发方法，设计和实现了基于B／S模式的电力企业指标管理信息系统。     

EXPLO-500T型拖拉机式地震钻机

万程欣,EXPLO-500T型拖拉机式地震钻机．物探装备，2006，16（4）：314-316 EXPLO—500T型拖拉机式地震钻机采用大马力拖拉机底盘、全液压控制，结构紧凑、操作简单、可靠性强、钻井效率高，特别适合林带、丘陵地区施工。