Design of dual-channel wide-range thermometer for true temperature measurement

A new thermometer is designed to measure and calculate the true temperature for a target. By selecting optimum measuring waveband&bandwidth and having the radiant and bright temperature measured at the same time, we could get the true temperature using some algorithms without the need to know the emissivity and (,T). The measurement is more accurate than currant multi-wavelength pyrometer by avoiding the errors of estimated emissivity and inner optics radiation. It's measuring range is from ambient temperature to 4000K. Results are given to support the design.     

Determination of the freeze-out temperature by the isospin thermometer

The high-resolution spectrometer FRS at GSI, Darmstadt, provides the full isotopic and kinematical identification of fragmentation residues in relativistic heavy-ion collisions. Recent measurements of the isotopic distribution of heavy projectile fragments led to a very surprising new physical finding: the residue production does not lose memory of the N/Z of the projectile ending up in a universal deexcitation corridor; an ordering of the residues in relation to the neutron excess of the projectile has been observed. These unexpected features can be interpreted as a new manifestation of multifragmentation. We have found that, at the last stage of the reaction, the temperature of the big clusters subjected to evaporation is limited to a universal value. The thermometer to measure this limiting temperature is the neutron excess of the residues.     

测量爆炸火焰真温的多光谱温度计的研制

研制了一种可用于大型爆炸现场的、测量爆炸火焰真温的多目标多光谱温度计.此温度计在爆炸的瞬间,同时对棱镜分光后的多个光谱带下的爆炸火焰辐射能量进行采集,利用二次测量法得出爆炸火焰的真温及发射率.在光路中采用了光纤远传技术和光纤耦合技术,极大程度上解决了仪器核心部分的防震、防爆、防电磁干扰的问题.采用高速采集和多级放大解决了爆炸时间短、温度变化剧烈、信号难于采集的问题,同时采用无线远传的结构保证了工作人员的安全.     

强磁场下锗电阻温度传感器的磁致电阻效应研究

以锗温度传感器GR-1400-AA为研究对象,研究了其在0～16 T磁场下、2～100K温区内的磁致电阻效应。结果表明:在2～20K温区,GR-1400-AA磁效应随温度的升高急剧降低,且场强越高磁效应的变化率越大;在20～100K温区,磁效应随温度的升高趋于平缓;GR-1400-AA磁效应随场强的升高而升高,且温度越低,磁效应的变化率越高,2.1K、16T处的磁效应为2120.3%;GR-1400-AA由磁阻引起的测量温差随温度的升高而升高,随场强的增大而增大,且全为负温差,在6K、2T处和16T、100K处的测量温差分别为-0.24K、-60.4K。不推荐应用在磁场环境下。     

宽温度范围微型人眼安全激光器

报道了一种宽温度适应范围的微型化人眼安全激光器。采用中心波长940nm的二极管作为泵浦源,Er3+/Yb3+共掺磷酸盐玻璃作为增益介质,Co2+:MgAl2O4作为被动调Q晶体,研究了微型激光器的结构和激光在宽温度范围下的输出特性。当泵浦能量9mJ,重复频率10Hz,泵浦脉宽5ms时,获得了单脉冲能量130μJ,脉宽5.5ns,峰值功率大于20kW的激光输出,光束质量因子为1.3。采用真空封装工艺,在-40~50℃温度范围内,自然冷却方式下激光器稳定输出,功率不稳定性波动小于5%。     

宽温度范围微型人眼安全激光器

报道了一种宽温度适应范围的微型化人眼安全激光器。采用中心波长940 nm的二极管作为泵浦源,Er3+/Yb3+共掺磷酸盐玻璃作为增益介质,Co2+: MgAl2O4作为被动调Q晶体,研究了微型激光器的结构和激光在宽温度范围下的输出特性。当泵浦能量9 mJ,重复频率10 Hz,泵浦脉宽5 ms时,获得了单脉冲能量130 J,脉宽5.5 ns,峰值功率大于20 kW的激光输出,光束质量因子为1.3。采用真空封装工艺,在－40~50 ℃温度范围内,自然冷却方式下激光器稳定输出,功率不稳定性波动小于5%。     

A thermometer for nonspinning solid-state NMR spectroscopy

We discuss a method to determine temperature in a static NMR experiment from the temperature variation of the lead nitrate peak shift.     

A microcomputer-controlled vacuum adiabatic calorimeter for the temperature range 4.2–300 K

In this paper, we describe the operation of a vacuum adiabatic calorimeter controlled by a Rockwell AIM 65 microcomputer, which is suitable for specific heat measurements in the temperature interval 4.2–300 K. The system measures and calculates the specific heat and the results are printed out on a thermal tape. The cryostat, the electronic circuitry and the software are described. Results obtained using a pulsed heat technique on a specimen of high purity copper are given and compared with values reported in the literature.     

The magnetic susceptibility of dilute CuFe alloys in the temperature range 1.7–300 K

The paramagnetic susceptibility ofCuFe alloys (100–300 ppm Fe) has been measured in the temperature range 1.7 to 300 K. The susceptibility is very well represented by the expression $$\chi = \chi _0 + \frac{{C_1 }}{{T - \theta _1 }} + \frac{{C_2 }}{{T - \theta _2 }}$$ the first and second Curie Weiss terms being associated with single and paired iron atoms respectively. A Cu_0-9 Au_0-1 Fe alloy was also studied.     

铑铁电阻温度计低温性能测试

针对一种商用铑铁电阻温度计进行了低温下的工作性能研究。对传感器进行了常温和液氮温度下的两点校正,校正结果验证了厂商提供的电阻温度拟合关系式。另外,还对该铑铁传感器连续进行了三次热循环实验。实验前,传感器的液氮温度稳定性优于20mK,而在实验后其温度稳定性优于30mK,满足工程应用的要求。所有实验结果表明,该铑铁电阻温度计性能可靠稳定,为其在超导磁体系统中的进一步应用提供了基础。     

207Pb chemical shift thermometer at high temperature for magic angle spinning experiments

The temperature dependence of 207Pb chemical shift in magic angle spinning (MAS) NMR spectrum of Pb(NO3)2 provides a sensitive method to calibrate sample temperatures in MAS NMR. The temperature dependence is uniform in the temperature range between 30 degrees C and 400 degrees C. The NMR sensitivity and the line width are also favorable.     

A method for magnetoptic studies on crystals in the temperature range of helium superfluidity

Test results are given on a method for magnetoptic studies on crystals down to temperatures of about 1.2°K.We are indebted to A. B. Fradkov for valuable assistance.     

A Teflon pressure-transducer-specimen bond for ultrasonic measurements over a wide temperature range

A major limitation for the application of megahertz ultrasonic techniques to the study of the properties of solids is the problem of finding transducer-specimen bonds useful over a wide temperature range. A Teflon pressure bond has been developed and tested. It appears to overcome most of the problems, and promises to allow for many studies previously more difficult or impracticable.     

多光谱辐射测温技术测量火工烟火药剂燃烧温度

利用瞬态光谱辐射仪分析了火工烟火药剂燃烧火焰辐射光谱分布,介绍了多光谱辐射测温技术的工作原理。结合火工烟火药剂燃烧火焰特征光谱分布状况设计研制了具有12个工作通道的多光谱辐射测温系统,测试者可根据被测火焰光谱辐射分布状况选择合适的工作通道进行分析计算。该系统由光学部分,电路部分,数据采集部分及数据处理部分组成。文章以黑火药为例,应用该系统对其燃烧火焰的辐射能量进行了测定,经过迭代计算后给出黑火药燃烧温度随时间的变化曲线。实验证明,在分析被测火焰特征光谱分布的前提下,选择合适的光谱工作通道,多光谱辐射测温系统能够很好地应用于火工烟火药剂燃烧温度的测定,为火工烟火药剂燃烧输出特性的研究奠定了基础。     

Dynamic range of materials for the magneto-optic imaging of magnetic fields

The range of rearrangement of the natural domain structure of epitaxial garnet ferrite films in magnetic fields produced by conventional recording magnetic media was calculated using numerical methods. Maximum and minimum periods of the recording medium signalograms that could be imaged using the fillm domain rearrangement were obtained as functions of the recording medium and film parameters.