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1.
针对敦煌莫高窟洞窟内微环境的改变特别是温度、湿度以及二氧化碳浓度的变化对洞窟内的壁画、佛像等珍贵文化遗产的保存具有重大影响的问题,采用CFD仿真技术对敦煌莫高窟进行建模仿真,研究其中温湿度、二氧化碳变化规律,进一步设计一套微环境控制系统使洞窟内的温度、湿度保持恒定以及降低二氧化碳的浓度。实验结果表明设计的微环境控制系统对于调节微环境的温度、湿度以及二氧化碳的浓度具有一定的效果。  相似文献   

2.
基于Zigbee无线传感器网络的温室测控系统   总被引:5,自引:1,他引:4  
为了克服有线测控系统接线复杂和抗干扰性差的缺点,开发了一种基于Zigbee无线传感器网络的温室测控系统。测控系统由上位PC机、基于CC2430的中心控制节点和传感器节点以及传感器模块组成。在分析温室测控系统特点的基础上,确定采用星形网络拓扑结构。搭建了具有1个中心控制节点和6个无线传感器节点的无线传感器网络。设计了温度、湿度和光照度传感器节点的硬件电路。用C语言在IAR Embedded Workbench for MCS-51 Evaluation环境下开发无线传感器节点程序。基于Visual C++6.0平台开发了上位机控制系统软件。将6个传感器节点均布在70 m×10 m温室中进行了试验,温度、湿度和光照度误差均在3%之内。  相似文献   

3.
植物无糖组培微环境控制是当今研究的一个热点.通过对植物无糖组培箱的改进,设计安装了箱内环境控制系统,实现了对培养容器内的CO2浓度、温度和湿度的自动检测,以及CO2浓度的自动控制.试验结果表明,明期内箱体中CO2浓度控制在1 950×10-6-2400×10-6范围内,控制稳定性好.CO2浓度、温度检测值与明期、暗期直接相关,温度主要受控于房阃的温度变化和照明灯具产生的热负荷.文章最后对控制系统的性能进行了评价,并提出了改进的方法.  相似文献   

4.
基于RS-485总线的温室环境监测系统   总被引:1,自引:0,他引:1  
文中设计了一套能实时控制温室内温度、湿度、以及CO2浓度等多参数的温室环境监测系统.该系统以PC机为上位机,低功耗单片机P89LPC932为下位机,由一台PC机与多台下位机组成主从式分布结构,采用总线式RS - 485通信网络进行数据传输,可实时传输各环境参数值从而实现远程控制.  相似文献   

5.
在温室环境监测中,有线传感器网络存在诸多问题,如布线复杂、传感器位置不灵活、节点延展性差、电缆老化腐蚀等问题。针对以上问题,采用ZigBee技术基于CC2430构建了无线传感器网络,用于监测温度、湿度、光照强度、二氧化碳浓度。并基于Modbus协议构建了RS485总线通信系统,实现了多温室传感器网络与上位机的通信。该系统传感器布置灵活、低功耗、易于安装维护及扩展,具有成本较低、实用性较强的优点。  相似文献   

6.
仓库环境控制系统的设计   总被引:1,自引:0,他引:1  
防潮、防霉、防腐、防爆是仓库日常工作的重要内容。本文介绍了一种以DHT11数字温湿度传感器、AT89S52单片机、315M无线收发模块为主的仓库温度湿度控制系统。本系统采用DH11数字温湿度传感器与AT89S52组成温度湿度实时采集系统进行实时的采集。随后将采集的数据通过单片机串口发送方式由315M无线收发模块将采集的数据传送至数据处理中心处理,根据预设的温度、湿度值决定是否驱动控制继电器驱动风机、加湿机、升温机工作,从而实现对温度、湿度的控制。  相似文献   

7.
为了提高生猪养殖的质量及自动化水平,设计了一套基于Zigbee的猪舍环境自动监控系统,系统运用各种传感器组成无线传感网络实现猪舍环境中的温度、湿度、光照强度、二氧化碳浓度参数的监测,依靠Zigbee无线数传技术将采集的数据传输至智能监控中心,根据在监控系统上设定的安全阀值控制风机、湿帘、灯光等设备的运作,以实现用户对猪舍的监测与控制,达到养殖环境的全自动智能化监控功能,该系统节约了人力资源,减少了成本投入,提高了养殖质量。  相似文献   

8.
本文基于ITU-BUS"单总线"提出了一种新的粮情检测和控制系统设计方案,该系统由测量控制单元和数据处理中心组成,可以实现粮仓内温湿度等粮情信息的实时采集、通信和处理。温度测量精度可以达到±0.5℃,湿度测量精度为±3%RH。温湿度直接以"单总线"的数字方式传输,大大减少了系统的电缆数,提高了系统的稳定性和抗干扰性。  相似文献   

9.
针对温室大棚生产过程中,影响大棚生产的几个关键因素,设计了温室大棚智能监控系统。本系统主要以单片机为核心,设计基于单片机实现了大棚内温、湿度及其光照量的自动检测、显示、阈值报警、智能化无线传输及启动继电器控制等多功能的温室环境参数监测控制系统,且系统低成本、低功耗、便携易操作,农户可以轻松了解和控制自家大棚的温度、光照强度、土壤湿度等,从而实现科学化种植以提高大棚产量,具有一定的实用价值。  相似文献   

10.
介绍了一种基于无线传感网络的温室控制系统,该系统利用传感器测量温室中的温度、湿度及光照度等;利用ZigBee技术实现温室主要参数的远程传输,利用在线最小二乘支持向量机(Online Least Square Support Vector Machine),实现温室自适应控制。  相似文献   

11.
An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...  相似文献   

12.
The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...  相似文献   

13.
黑棣  郑美茹 《机电工程》2016,(11):1315-1321
针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。  相似文献   

14.
The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.  相似文献   

15.
The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...  相似文献   

16.
The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....  相似文献   

17.
马立新  王宏宇 《机电工程》2015,32(1):118-122
针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。  相似文献   

18.
A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.  相似文献   

19.
This article describes designing, implementation and tuning processes of multiple-tapped-delay-line (MTDL). Obtained MTDL can be implemented in various field-programmable-logic-devices (FPGA) devices and applied for time-to-digital-converters (TDC) construction. The task of tuning process is the tapped-delay-line (TDL) linearisation, and consists of two stages. The first stage depends on selecting an appropriate configurable-logic-block (CLB) for particular delay-segment realization and selecting proper connection between these blocks. The second tuning stage, that is essential from this article viewpoint, depends on inter CLBs connecting wires delay regulation realized directly by load regulation. The Load regulation depends on connecting an appropriate number of unused three-state-buffers or CLB inputs to the wire which delay is adjusted. Depending on the number of inputs connected to the wire its capacitance changes that influences its time-constant and finally changes its time-delay.The MTDL mathematical model, obtained characteristics and results of time-interval (TI) measurements are also presented. The derived TDL model provides information about how the particular wire delay should be changed and in which order the changes should be executed. This makes the designing process predictable and easy to carry out. Presented characteristics confirm the proper operation of presented linearisation technique. The proper operation of the whole measuring module is confirmed by obtained TIs histograms presentation.  相似文献   

20.
Giannuzzi LA  Utlaut M 《Ultramicroscopy》2011,111(11):1564-1573
30 keV Ga+ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z2, and shows a non-monotonic relationship between contrast and Z2. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z2, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.  相似文献   

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