共查询到20条相似文献，搜索用时 218 毫秒
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研究目的:研制一种试验装置,以实现对非饱和土土-水特征曲线温度效应的有效测试。创新要点:1.研制了一种温控非饱和土三轴试验装置,包括加载系统、吸力控制系统和温度控制系统;2.利用研制的温控非饱和土三轴试验装置,对不同温度(25,40和60°C)以及不同应力(40,100和200 kPa)条件下的非饱和土土-水特征曲线进行了试验测定。研究方法:1.总结分析已有的温控三轴仪所采用的加热方式的优缺点,提出环向加热压力室内水体的方法;2.基于GDS非饱和土三轴仪,研制可实现温度控制功能的温控非饱和土三轴仪(图1、2);3.开展不同温度及不同应力条件下非饱和土土-水特征曲线的试验研究。重要结论:1.所研制的温控非饱和土三轴仪的实用效果得到验证;2.温度的升高将引起非饱和土持水性能的降低。 相似文献
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《实验室研究与探索》2017,(3):70-74
设计了一款具有测温、保温、提醒等多重特性的智能水杯。以STC89C51单片机为电路控制核心,对温控智能水杯系统的键盘显示及接口、DS18B20温度传感、报警等硬件电路进行了设计;采用Visual C++6.0作为软件开发工具进行编程,实现了单片机与LCD1602的接口电路设计;另外用户可通过红外遥控对温控智能水杯进行加热、定时等多种简便操作。结果表明:该款智能温控水杯具有的多重优点,弥补了传统水杯的不足,能极大地满足用户的需求。 相似文献
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谢完成 《娄底职业技术学院学报》2007,(2)
CC4046集成电路锁相环采用RC型压控振荡器,外接RC作为充放电元件,电路简单、成本低廉、实用价值大,可广泛应用于广播电视系统,各种通信系统,以及频率合成,自动控制及时钟同步等技术领域。利用数字集成锁相环组成温控变频电路可以克服常见温控系统可靠性低、抗干扰能力差的缺点,为温度的精确测量及需要进行温度检测控制的设备提供了一种可行的电路设计方案。 相似文献
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赵桂英 《数理化学习(初中版)》2000,(5):42-42
题目 电饭锅的原理如图1所示,煮饭时,按下温控开关K与a、b接触．红色指示灯亮;饭熟后,温控开关自动断开．当饭温度低于68℃,K自动上升与触点C接触,电饭锅处于低温加热状态．黄色指示灯亮;到68℃时即自动断开,如此往复．(红、黄指示灯电阻很小,计算时可忽略不计) 相似文献
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匡再德 《第二课堂(小学)》2006,(5)
一、电饭锅电饭锅的原理如图1所示,煮饭时,按下温控开关S与a、b接触,红色指示灯亮; 饭熟后,温控开关自动断开,当饭温度低于68℃,S自动上升与触点C接触,电饭锅处于低温加热状态,黄色指示灯亮;到 68℃时即自动断开(红、黄色指示灯电阻很小,计算时可忽略不计)． 相似文献
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《实验室研究与探索》2017,(5):53-56
开发了一套具有人机实时交互功能的水冷式温控实验系统"iWater"。该系统控制部分采用闭环结构:由PTC陶瓷片模拟发热对象,STM32型微控制器根据DS18B20温度传感器提供的实时温度反馈,经过PID运算,对H桥驱动输出PWM指令,从而对水冷机进行调压调速,实现对温度的恒值控制。扩展多种人机交互功能:通过红外遥控模块,可实时设定温度、控制策略以及各类参数;现场输出选取TFT-LCD屏,可实时显示温度曲线;实验数据通过USART通道,在上位机的VisualScope界面实时绘制温度曲线,完成对实验数据的观察、存储与分析。最终完成了样机制作,实验结果验证"iWater"实验系统的有效性。 相似文献
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针对目前公交车制冷制热系统不能实现智能控制的问题,设计了一款基于单片机的公交车温控系统,此系统通过在车内前、中、后部位安装温度控制按键,让乘客自己决定车厢内的温度,其工作原理为：温度传感器和液晶显示器对实时温度进行采集和显示,单片机处理按键数据后控制继电器,实现车厢内温度的改变。 相似文献
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本系统采用单总线高精度温度传感器 DS18B20采集温度数据,利用单片机 AT89C51作为测量节点控制单元,将采集到的温度数据通过 RS-485收发器,在 RS-485总线上进行远程传输。在 PC 机上通过 VC＋＋6.0设计串口通讯与温度显示软件,将温度数据显示在 PC 机上,实现温度数据的远程实时检测。该系统设备简单、价格低廉,适合工业化。 相似文献
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Objective: To determine the range of body temperature in a group of healthy Chinese term neonates over the first 72 hours of life and to assess the influence of body weight, gestational age and route of delivery. Method: All 200 consecutive cases of neonates delivered at our hospital from March to August 2001 were included in this retrospective study. Temperatures were measured immediately after delivery, after 30 minutes, 1 hour, 2 hours, 8 hours and 15 hours and on the 2nd and 3rd day. Axillary temperatures ranging from 36.5 oC to 37 oC were regarded as normal. No cases of maternal fever or systemic infection of the newborns were discovered. All infants were discharged in good general condition. Results: The mean rectal temperature at birth was 37.19 ℃. The lowest average temperature was reached at 1 hour after delivery (36.54 ℃) with a significant difference between natural delivery (36.48 ℃) and section (36.59 ℃) (P<0.05). Temperature subsequently rose to 36.70 ℃ at 8 hours and 36.78 ℃ at 15 hours (P<0.05). Hypothermia was seen in 51.8% and hypothermia in 42.5% of the patients. On the 3rd day after delivery, 96% of all temperatures were in the normal range. A significant relation was found between hypothermia and both low birth weight (P<0.001) and low gestational age (P<0.05). Conclusion: The reference range presently used did not include all physiological temperatures in the first 72 hours of life. Considering other factors, such as birth weight, route of delivery, gestational age and body temperature on the 2nd and 3rd day of life, may help to correctly assess the significance of temperatures beyond the reference range. 相似文献
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介绍一种利用红外线温度传感器,间接检测开关触点及导体连接点接触电阻变化的技术。采用PC104工控机作为上位机,进行数据处理、逻辑分析,采用P89C58单片机作为下位机,进行温度信号处理、A/D转换。通过RS485总线组成分布采集和集中处理系统,可对开关触点或导体连接点接触电阻预测,及早发现隐患,提前采取措施,避免停电事故。 相似文献
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研究一种基于AT89C52单片机和DS18B20数字温度传感器来进行温度测量的方法,研究了温度传感器芯片、单片机与温度传感器接口电路,以及实现温度信息采集和数据传输的软件.通过proteus进行仿真,结果表明该系统具有结构简单、电路典型和控制方便等优点.整流中两输出滤波电感稳态电流的均流问题,通过PSPICE仿真验证了分析的合理性. 相似文献
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A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from 20°C to 70°C. The results show that the temperature sensor has high temperat... 相似文献
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利用公式△H=-0．1196n／A计算了乙醚和丙酮分别在氧气和空气中燃烧反应的温度,并推测了乙醚和丙酮燃烧反应的机理．乙醚在氧气中燃烧反应的火焰温度理论值为3272K,与测定温度3134K接近,误差为4．40％．丙酮在空气中燃烧反应的火焰温度理论值为1292K,与测定温度173K接近,误差为1．49％．根据乙醚和丙酮燃烧反应的火焰温度,推测乙醚和丙酮燃烧反应机理为：（1）O2＋hv→2O·;（2）（C2H5）2O→4C＋4H2＋H2O（乙醚）,CH3COCH3→3C＋2H2＋H2O（丙酮）;（3）H2＋O·→H2O＋hv;（4）C＋O·→CO＋hv;（5）2CO＋O2→2CO2． 相似文献
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Characteristics of fluoride emission from five clay minerals (montmorillonite, kaolinite, vermiculite, geothite, and allophane)
as affected by temperature, heating time and addition of calcium compounds were studied. Marked increase of the fluoride emission
rate was noticed with increase of temperature. The fluoride release, began at 500°C–600°C, and the main bulk of the fluoride
emission occurred at the temperature of about 800°C. The loss of crystalline water was primarily responsible for the increase
of fluoride emission. When minerals were heated at 800°C, The fluoride emission rate from the clay minerals reached the highest
after heating for 1 hour. The samples treated by CaO, CaCO3, Ca(OH)2, Ca3(PO4)2, and CaSO4 had 55.45%, 59.58%, 46.45%, 54.31%, 31.25% reduction in the fluoride emission from montmorillonite at the temperature of
800°C, respectively. CaCO3 had the highest fluoride fixing capacity compared to other calcium compounds.
Project supported by the Special Funds for Major State Basic Research Project 973 (G1999011809) and Natural Science Foundation
of Zhejiang Province. 相似文献
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Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained. 相似文献
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INTRODUCTION The use of anaerobic process to treat municipal organic solid waste (MOSW) has dramatically in-creased recently. Anaerobic digestion can be carried out under ambient (<25 °C), mesophilic (25~45 °C) and thermophilic (>45 °C) conditions (El-Mashad et al., 2004). Thermophilic digestion has many advan-tages such as higher metabolic rate and higher con-sequent specific growth rate compared with meso-philic digestion, although the thermophilic bacteria death rate is higher (… 相似文献