实验研究气流扰动对R161燃爆特性的影响

低GWP制冷剂以其优良的环保性能将在制冷剂替代及新制冷剂研发中发挥重要作用,但是其中大部分均具有可燃性。因此本文以R161为研究对象,基于自主搭建的制冷剂燃爆极限测试系统,试验研究了R161的燃爆极限和燃烧火焰特性,以及局部气流扰动对其燃爆下限和燃烧火焰特性产生的影响。结果表明,在常温常压条件下,R161的燃爆极限范围是3.9%～16.5%;附加特定局部气流扰动使得R161在浓度明显低于其正常条件下燃爆下限时能被点燃,可能会一定程度的降低燃爆下限;在同等浓度条件下,气流扰动将可能增强火焰燃烧程度。     

单片机在测量金属温阻特性实验中的应用

本文论述了单片微机系统测量金属导体温阻特性的实验原理，实验装置及Ｒ／Ｖ转换电路，对一般实验的数据采集与转换具有一定参考价值。     

扩散时间对乙烯-空气燃爆特性的影响

为探究在有限空间中,初始压力为0.25MPa、两处乙烯气体瞬时源在不同扩散时间下的燃爆特性,在内径200mm、高5 400mm的立式激波管中,采用上下进气方式,在强起爆条件下,测定5个不同扩散时间下3种浓度的乙烯-空气混合气体(C2H4-Air)的燃爆参数。实验结果表明,扩散时间大于1h后,3种浓度的C2H4-Air混合气体燃爆参数趋于一致。4.00%(体积分数)C2H4-Air在当前实验条件下未能达到爆轰。6.67%C2H4-Air在5个扩散时间均可达到爆轰,扩散时间为1h时的爆压、爆速分别为4.24 MPa、1 719m/s。8.89%C2H4-Air在0.08h扩散时间下只发生爆燃,扩散时间为0.5h及以上发生爆轰,扩散时间为1h时的爆压、爆速分别为4.31 MPa、1 813m/s。通过烟熏技术捕捉到6.67%、8.89%的C2H4-Air混合气体的爆轰波胞格,胞格宽度分别为8.22、14.15mm,长宽比分别为1.44、1.57。     

高Tc超导谐振器微波特性研究

研究了高Ｔｃ超导谐振器的微波特性特别是表面电阻Ｒｓ和磁场穿透深度λ,给出了Ｒｓ随温度变化的曲线以及穿透深度的测量结果。实验中采用了由ＹＢａ２Ｃｕ３Ｏ７薄膜和蓝宝石片构成的平行板谐振器。     

用H_α光谱测量方法研究简单磁镜装置中热电子等离子体的性质

本文描述了简单磁镜装置中微波加热的氢等离子体的Ｈ_α面发光度特性的实验结果。与Ｘ射线、反磁探针、朗缪尔探针等测量结果相结合，给出了ＭＭ－２简单磁镜装置中ＥＣＲ等离子体的一些基本特性。     

光泵NH3分子远红外激光研究

运用量子系统的密度矩阵理论，采用迭代法计算了光泵ＮＨ３分子远红外超辐射和腔式激光的频谱特性和相应的最佳工作气压。理论计算表明相对于超辐射方式，光泵腔式ＮＨ３分子远红外激光具有宽带辐射以及纵向调谐特性，且总的输出光强在一定条件下得到提高，最佳工作气压也较低。在实验上对ＴＥＡＣＯ２－１０Ｒ（８）和９Ｒ（１６）泵浦的Ｎ 红外超辐射和腔式激光器产生的远红外辐射进行了测量。结果表明理论计算与实验结果相符。     

射频场强度对稳态核Overhauser效应增强的影响

通过分析在ＲＦ场照射下自旋体系的稳态特性，指出了区分稳态和饱和态的概念是非常必要的。用推广的Ｓｏｌｏｍｏｎ方程描述稳态ＮＯＥ实验，给出了稳态ＮＯＥ实验增强因子的修正表达式，并用实验证明了它的正确性。 关键词：     

BR—PVA固体膜在四波混频相干场中的光栅特性位相共轭波的暂态行为

利用Ａｒ离子激光简并四波混频（ＤＦＷＭ）技术，对细菌视紫质（ＢＲ）－苯乙烯醇（ＰＶＡ）固体膜的位相共轭波特性进行了理论和实验研究。采用ＢＲ光循环的双态模型入粒子数速率方程，以及全息光栅理论描述了该体系的ＰＣ波的衍射效率、时间响应和饱和特性，给出了相应的表达式。讨论了该体系在ＤＦＷＭ场中的光栅机制和上述特性对于输入波的偏振态，强度和强度比，到达样品的时间和形成的初始浓度光栅等参数的依赖关系。实验结果     

ER液体的液──固转变机理

本文介绍了ＥＲ液体的液、固转变机理及ＥＲ液体的组分和特性。     

CARS技术中泵浦激光光场相干特性的研究

本文从理论上指出，在分子振动能级的横向弛豫时间远小于激光相干时间的条件下，相干反斯托克斯喇曼散射（ＣＡＲＳ）信号能够反映出激光光场的相干特性，据此可直接了解其相干时间并推算出激光的线宽。实验记录了苯、甲苯的ＣＡＲＳ光信号与激光延时时间的关系，得出了激光的相干时间和线宽。     

单级自动复叠混合工质制冷循环的实验研究

由于压缩机压比的局限,制约着单一制冷剂的压缩回热循环发展,本系统采用单一压缩机和混合工质的自复叠制冷循环系统取得了较好的制冷效果。文中对单级自动复叠制冷系统进行了理论模拟,并设计和搭建了实验台进行分析。通过理论和实验数据的分析得出混合工质组合R600a/R23,并初步得到最优配比。     

The characteristic equation and solution of circular-groove guide

The characteristic equations of circular-groove guide have been given under first-order and second-order approximation. The cutoff wavelength and guide wavelength have been calculated. The theoretical results have been verified by experimental measurements.Supported by the Natural Science Fundation of P. R. China     

The study of diffraction radiation oscillation

Theoretical and experimental study of Diffraction Radiation Oscillator (DRO) is reported in this paper, it is the first work done in P. R. China. The sphere-cylindrical open cavity used in the DRO has been analysed, the method for testing the field profile and the cold measurement of the open cavity have been worked out. The experimental device was manufactured in our lab. and the theoretical analysis and experimental study of the device have been carried out. The main experimental results are: from 2000 V to 4000 V, the tube operates in the 60–87 GHz band, and the maximum output power is about 800 mW.     

小功率高转速蒸汽透平试验研究和优化

小功率高转速蒸汽透平试验研究和优化邵振麒（同济大学汽车工程系上海２０００９２）关键词：小蒸汽透平，效率，优化１前言回收能量和工业装置的余热及利用太阳能等新能源是节能和环保的重要措施，由此产生的机械能可供发电，气体增压等多种用途。在一些废热量不大且不宜...     

Nd:YVO4/KTP环形倍频激光器三次谐波稳频碘吸收谱线超精细结构的研究

采用三次谐波稳频的方法,对Nd：YVO4／KTP环形倍频激光器的碘吸收谱线的超精细结构进行研究,在实验上观测到的两组谱线的超精细结构与理论值基本相符,其中,观测到的R(70)36-1谱线属于第一激发态跃迁,这一结果尚未见报道。     

Temperature dependence of the refractive index of optical fibers

Many experimental investigations on the temperature dependence of the refractive index of optical fibers have been reported previously, however a satisfying theoretical explanation for it is still absent. In this paper, a theoretical model about the temperature dependence of the refractive index of optical fibers is presented and it is in agreement with the previous experimental results. This work is a significant reference for the research and development of temperature sensors based on optical fiber delay lines.     

惰性气体氦、氖、氩原子与氢(氘、氚)分子碰撞截面的理论计算

原子分子相互作用在许多物理过程中都十分重要.原子分子碰撞过程中转动激发截面的研究是确定原子与分子间相互作用的理想方法,许多理论和实验工作者在这方面做了大量工作,并得到理论和实验数据.本文用密耦近似计算了惰性气体He、Ne、Kr与h2、D2、T2碰撞的弹性和转动激发截面,原子入射能量分别为0.05 eV、0.15eV、0.20eV和0.25eV.     

Pauli-forbidden intermediate states and operator identities

The E.S.R. spectra of the β-fluoroisopropyl radical and the β-fluoro, β,β-difluoro and β,β,β-trifluoroethyl radicals have been recorded in fluid solutions. The conformational preferences and barriers to internal rotation in these species have been determined from an investigation of the temperature dependence of the β-fluorine and β-proton hyperfine coupling constants. The experimental hyperfine splittings have been compared with theoretical values calculated by the INDO method.     

Reflection of compressional and Rayleigh waves on the edges of an elastic plate with quadratic nonlinearity

Previous ultrasonic studies have demonstrated that measurements of material nonlinearities can provide a means for detecting early signs of fatigue damage using both compressional (P) and Rayleigh (R) surface waves. However, these experimental studies have typically been limited to the direct wave arrival between the source and receiver in simple geometries where no reflection occurs. In particular, the degree of material nonlinearity is often quantified by the ratio of the cumulative amplitude of the first harmonic to that of the fundamental for the direct arrival only. Hence a practical question arises over the interpretation of ultrasonic measurements of material nonlinearities in the presence of reflected nonlinear waves. Thus, this article investigates the reflection problem of P or R waves at the edge of a homogeneous plate with quadratic nonlinearity using both a theoretical formulation, based on perturbation analysis, and direct numerical simulations using a Cellular Automata formulation. The numerical approach is first validated against an existing theoretical formulation for reflecting nonlinear P waves. It is then used to simulate the nonlinear reflection of R waves at a plate's edge for which no closed-form formulation is presently available.     

Analytic method of arbitrary cross section open groove guide

Groove guide is one of the waveguides that have been used at millimeter and submillimeter waveband. This paper analyzes arbitrary groove guides by means of the eigen-weighted boundary integral equation method that uses the eigenfunctions of a fictitious regular boundary as weighting functions. In comparison with the theoretical and experimental results published, the numerical results for rectangular, circular and V-groove guides using this method are exact enough with fast convergence and less calculation.The Project Supported by National Natural Science Foundation of P.R. China