Ultrahigh and controllable drain current peak-to-valley ratio innegative resistance field-effect transistors with a strained InGaAschannel

Negative resistance field-effect transistor (NERFET) devices using either strained InGaAs or unstrained GaAs channel layers have been fabricated. The strained InGaAs channel NERFET's show strong negative differential resistance and large drain current peak-to-valley ratio. The peak-to-valley ratio of the InGaAs channel NERFET is more than 3000 at room temperature and larger than one million (10⁶) at 77 K. The peak-to-valley ratio is controllable by adjusting the collector voltage     

不锈钢网架(壳)技术及其应用

本文总结了多年来不锈钢网架的研究成果 ,并介绍了部分不锈钢网架的工程应用     

学习新版建筑工程施工质量验收规范的体会

结合新版建筑工程施工质量验收规范的学习和施工实践 ,介绍了新版标准与旧标准的差异和特点 ,并就如何贯彻实施新标准、准确掌握检验批等问题作了分析 ,提出了执行中的相关注意事项。     

用科学发展观推进水利“十个转变”

树立和落实科学发展观，除不断深化对科学发展观的科学性、必然性和战略性、指导性的认识，不断增强坚持和落实科学发展观的自觉性和坚定性外，更重要的是要将科学发展观付诸实践，见诸行动，贯穿到促进经济社会发展和推动改革开放的各项工作中去，在实践中将科学发展观转化为强大的物质力量。水利行业贯彻和落实科学发展观，关键在于认清形势，立足实际，把握重点，明确方向，在扎实推进“十个转变”上下功夫。     

Nonlinear dynamic characteristics of piezoelectric bending actuators under strong applied electric field

Dynamic characteristics of piezoelectric bending actuators under low and high electric fields are studied using the asymptotic theory of nonstationary vibrations. The proposed nonlinear model predicts the changes in fundamental resonant frequencies of the piezoelectric cantilever. The predicted resonance amplitude of the tip deflections of the piezoelectric actuators, which increases with the increase in the magnitude of the electric field, well agrees with the experimental results. Additionally, the decrease in the mechanical quality factor with the increase in the electric field, the tip deflection of piezoelectric actuators near resonance frequency,and the amplitude of the tip deflection at the fundamental vibration tone under an applied electric field varying with time have also been obtained using the present model.     

异构空间信息的分级共识模型研究

Internet上异构、分布的空间信息因各自独立、相对封闭而无法相互沟通和协作,从而形成了空间信息孤岛。论文利用计算机的知识表示理论和Ontology技术能够明确表达相关领域共识的特点,探索性地提出了异构空间信息的分级共识模型。该模型为解决上述问题提供了一条切实可行的新思路。     

浅析硫磺回收装置中的自动控制设计

大规模高含硫原油的炼制工艺必须配套设置脱硫和硫磺回收装置。笔者针对硫磺回收装置的特点,为确保装置的安全平稳运行,提出了该装置自动控制设计中需要严格监控的工艺参数及重点部位,叙述了仪表选型原则和精确测量与控制的原理和方法。