基于Sagnac光纤干涉仪的管道泄漏检测和定位技术

研制了一种基于Sagnac干涉仪的分布式光纤传感器,可实时进行管道泄漏检测与定位.阐述了该传感技术的工作原理和泄漏点定位方法,并推导了泄漏引起的光信号相位变化表达式。管道泄漏实验结果表明,水压为0.3MPa时,该技术能有效地检测到管道泄漏的发生并准确定位。     

用光波导光模光谱技术研究DNA-DNA结合蛋白相互作用

探讨了应用光波导光模光谱(Optical waveguide lightmode spectroscopy,OWLS)技术研究DNA-DNA结合蛋白相互作用的可行性和灵敏性。以固定在传感器芯片表面的DNA探针为捕捉分子,溶液中同时含有探针结合序列和NF—κB结合位点序列的寡核苷酸与NF-κB亚单位p50同源二聚体形成的DNA-蛋白质复合物为检测分子,用光波导光模光谱检测技术建立非标记DNA-DNA结合蛋白相互作用检测研究体系。利用这一体系对不同样品中NF-κB p50浓度和具不同NF-κB结合位点序列的寡核苷酸与NF-κB p50亲合和力进行检测。样品中低至0．33 nmol/1的NF-κB p50被光波导光模光谱检测出,不同的NF-κB结合序列与NF-κB p50亲合力有显著的差异。研究发现,光波导光模光谱技术可以用于DNA-DNA结合蛋白相互作用研究,所建立的非标记检测研究体系可以进行样品中结合蛋白含量高灵敏检测和核酸序列与结合蛋白的亲合力的检测研究。     

隔热材料的纳米成型与性能分析

经不同工艺和过程制备二氧化硅气凝胶,初步摸索出制备温度、溶剂、催化剂、反应时间最佳参数.在分析气凝胶干燥开裂的原因后,以三甲基氯硅烷(TMCS)为表面修饰剂,正己烷为干燥介质的表面改性工艺,一定程度控制了气凝胶的干燥收缩和开裂.在室温、常压下的通过不同的改性方案制备出四种不同气凝胶样品,揭示了改性条件、干燥温度对于气凝胶孔隙分布、微观结构的影响.     

Microwave structural studies of organoselenium compounds 1. Microwave spectra, molecular structure, and methyl barrier to internal rotation of dimethyl diselenide

The rotational spectra of nine isotopomers of dimethyl diselenide, CH₃SeSeCH₃, have been measured with a molecular-beam Fourier transform microwave spectrometer. The spectra were complex due to the presence of many isotopomers in natural abundance and the splitting caused by the interactions with two methyl internal rotors. The spectra were assigned and fit to experimental precision to an effective rotational Hamiltonian for molecules with two periodic internal motions. The spectra of the symmetric isotopomers are consistent with a C₂ equilibrium structure. The rotational constants were used to determine the r_s structure of the C-Se-Se-C frame with the results r(SeSe)=2.306(3) Å, r(SeC)=1.954(6) Å, ?(CSeSe)=99.8(2)°, ?(CSeSeC)=85.2(1)°. A barrier to internal rotation of the methyl groups of 395 ± 2 cm⁻¹ was derived from the internal rotation splittings.     

R600a／矿物冷冻油混合物表面张力

本文利用新改进的表面张力实验系统对R600a／矿物冷冻油混合物的表面张力进行了实验研究,其中R600a的质量分数分别为O．95、0．90和0．85,温度范围为253．15-333．15K。实验结果表明,随着含油量的增加,R600a／矿物冷冻油的表面张力逐渐减小,矿物油的存在对纯质制冷剂的表面张力有比较明显的影响。     

随机对流扩散方程的数值仿真

本文针对对流一扩散随机过程在随机输入（即随机输运和源项）,作用下进行数值仿真。我们先将对流扩散随机微分方程中的随机函数采用有限项截断的多项式浑沌展开（Polynomial Chaos Expansion）展开,再由Galerkin映射法得到求解浑沌展开系数的确定性方程组。这是一个在物理空间包含多尺度解的大方程组。为此我...     

Accumulation effect of SiO_2 protective layer on multi-shot laser-induced damage in high-reflectivity HfO_2/SiO_2 coatings

The accumulation effects in high-reflectivity(HR) HfO2/SiO2 coatings under laser irradiation are investigated.The HR HfO2/SiO2 coatings are prepared by electron beam evaporation at 1 064 nm.The laser-induced damage threshold(LIDT) are measured at 1 064 nm and at a pulse duration of 12 ns,in 1-on-1 and S-on-1 modes.Multi-shot LIDT is lower than single-shot LIDT.The laser-induced and native defects play an important role in the multi-shot mode.A correlative theory model based on critical conduction band electron density is constructed to elucidate the experimental phenomena.     

受阻酚AO-80/丁腈橡胶复合材料的压力-体积-温度关系研究

 研究制备了具有高阻尼性能的受阻酚AO-80/丁腈橡胶复合材料样品,采用动态粘弹性测试得到了损耗因子tan δ与温度T的关系曲线。分析表明,随着受阻酚含量的增加,tan δ峰的位置向高温方向移动,tan δ峰的峰值也逐渐提高;利用pvT高压膨胀计对样品进行了测试,采用Tait方程研究了其压力-体积-温度（pvT）性能,对此计算出Tait方程中的相应参数。结果表明,由Tait方程计算所得的pvT理论关系与定性实验结果一致,具有较好的规律性,即对AO-80/丁腈橡胶复合体系b₁值随AO-80量的增加而逐渐降低,AO-80量越大,该体系T_g时的绝对比容越小;b₂随AO-80量的增加而逐渐增大,AO-80量越大,该体系随温度膨胀越显著;b₃、b₄均为常数,即B为常数,复合材料的比容只与压力存在一定关联;同时用Tait方程计算所得的值与实验值的平均残差均小于0.02,吻合度较好;结果表明,Tait方程可以较好地描述该体系的pvT关系,为定量研究阻尼材料的pvT性能提供了理论指导。     

中波红外景象投影光学系统消热差设计

针对红外成像系统性能测试与评估的应用需求,设计了一套基于数字微镜器件的消热差的中波红外景象投影光学系统.探讨了红外视景仿真用投影光学系统的像差特性和设计方法,并对投影系统的无热化进行了分析.采用分光板和补偿板方案,解决了大相对孔径条件下投影系统的远心照明分光和像差平衡问题,提高了分辨率和均匀性,增大了视场.系统由远心投...     

锂铅合金释氚实验研究

由于锂铅合金因具有高增殖比、低活泼性和可能作为冷却剂的特点,被认为是最有潜力的能源堆包层氚增殖材料。在理论模型描述熔融锂铅合金氚释放行为的基础上,开展了中子辐照后Li₁₇Pb₈₃合金的离线氚释放实验。结果表明: 释放氚的化学形式99％以上为难溶于水的成分（HT或T2）; 氚滞留时间随载气中氢分压的增加而减小,氢分压达到1000 Pa后变为常数,且与实体积无关;氚释放速率对温度的依赖性符合Arrhenius定律。以此为基础得到的氚在熔融锂铅中的动力学参数结果,虽与文献值有差异,但同样证明了在633—973 K的范围内, 氚从液态锂铅到气相的整个释放过程中起决定作用的是氚在合金内的扩散和气\|液界面的多相反应重组。Lithium\|lead alloy is considered to be one of the most prominent tritium breeding materials for the fusion reactor blanket because of its high breeding ratio, and low reactivity and possible use as coolant. An out\|of\|pile experiment of tritium release from Li₁₇Pb₈₃ alloy was performed after neutron irradiation on the base of mathematical model to describe tritium release behavior from an eutectic lithium\|lead alloy. The results suggest that the dominant chemical form of the released tritium (>99%) was the water\| insoluble component (HT or T2). Tritium residence time decreased with increasing H₂pressure in carrier gas up to 1000 Pa, and above this concentration limit it became constant and not influenced by the plenum volume. The temperature dependence of the tritium release rate can be described by an Arrhenius law. Consequently, the present results on the kinetic parameters of tritium in molten Li₁₇Pb₈₃alloy are considered to be different from the values in literature, but it is the same that the overall release process is governed by the diffusion of tritium atoms in the Li₁₇Pb₈₃and by the heterogeneous reaction at the gas\|eutectic interface of the tritium atom recombination at temperatures from 633 to 973 K.