首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
自行制作的可控硅精密控温装置,采用PID控温技术,其控温精度可达10-3甚至10-4℃,远远大于继电器控温装置的控温精度(一般为10-2℃).将该精密控温装置用于基础物化实验,可大大提高实验精度.  相似文献   

2.
张达 《遵义科技》2010,38(2):41-42
温室番茄栽培成功技术的关键是选择抗病强、产量高、耐低温的优良品种,培育适龄壮苗,增施农家肥,垄作覆地膜,膜下暗灌,张挂反光幕,增强升温、保温、控温设施,并掌握各生长阶段的温度调节等技术。  相似文献   

3.
使用电加热器的卫星主动控温回路是一种重要的主动热控措施,通过简明扼要的机理分析建立起该主动控温过程中受控对象温度变化的动态方程,得出了稳态控温、瞬态控温两种基本的控温模式下主动控温回路电加热器功率需求的计算表达式,给出了进行主动控温回路电加热器热功率设计计算的一般流程,较详细地分析了一个具体设计算例,为卫星主动控温回路设计计算提供了简便的计算模型和方法。  相似文献   

4.
沈景鹏  陶瑛  孙旭东 《贵州科学》2002,20(4):72-74,78
本文论述热电偶自动检定系统中控温方案的工作原理、硬件组成和主要技术问题的解决方法。  相似文献   

5.
基于虚拟仪器软件LabVIEW设计了一套多点精确控温系统。利用LabVIEW软件编写的测温和PID控温程序配合网络数据采集卡、固态继电器等硬件,可以实现对加热装置的多点精确测温和控温。该系统使用的B型热电偶的测温精度能达到0. 1℃。在800~1 800℃高温范围内,系统长时间定点控温波动能稳定在±0.5℃之内。采用星型结构的局域网可将设计的控温系统扩充至4047个测温节点和2024个控温节点,成为一个大型的测温控温系统。  相似文献   

6.
PIC单片机具有开放式可重构的软硬件体系,适合于对采样复杂、动态变化的物理现场进行控制。本文设计了PIC精确控温系统硬件架构,对温度检测模块和温度控制模块进行了分析,给出了程序流程和源代码。利用PIC精确控温技术对电子废弃物循环利用工艺进行改造,改造后效能明显得以改善。  相似文献   

7.
本文利用恒温槽热平衡条件、控温振荡电路的振幅平衡条件和控温电路中交直流放大器的传输函数,证明了振荡控温式恒温槽的缩减因数与恒温槽的热阻、整流滤波器的电压转换系数和直流放大器的放大倍数无关。  相似文献   

8.
提出相变控温储能材料机敏控制混凝土结构温度裂缝技术途径.在混凝土浇注过程中将相变材料掺入使之与混凝土结构一体化,利用相变材料在特定温度范围的热效应控制混凝土内部温度场,从而机敏控制温度应力防止温度裂缝.通过自行设计的温度测试系统,对相变控温混凝土控温性能进行实测研究,结果表明:相变材料不但可以降低大体积混凝土的最高绝热温升值,而且可以降低大体积混凝土升温速度和降温速度,从根本上防止了大体积混凝土温度裂缝的出现.  相似文献   

9.
本文介绍了微波理疗机中测温控温的重点难点,讨论了不同方案及特点,简述了应用自控原理控测技术。  相似文献   

10.
本文通过对控温轧制技术和自动控制技术的研制,把提高钢材的性能与自动控制钢温技术有效的结合,应用后了提高钢材的性能和质量,节约成本,提高经济效益.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号