降低接触网线工程损耗研究

分析了施工过程中线路定测的精准度、线索配盘的精准度及放线过程中停车位、断线点的选择不当等原因造成了电气化铁道接触线损耗过高,提出了准确配盘、严格工艺标准、改进机械设备等措施来降低接触线的损耗,节约成本。     

Optical time-domain reflectometry for distributed sensing of the structural strain and deformation

A unique structure of microbend optical fiber sensor (MOFS) for measuring tensile and compressive strain is described in this paper. The average measuring sensitivity for tensile strain is 35μ using 3 MOFS arrays. The repeatability and stability of MFOS are better than 18μ. The loss sensitivity of single-mode (SM) fiber and multi-mode (MM) fiber used in MOFS, as well as the relationship between the pulse width of diode laser and loss sensitivity are also studied in this paper. From these studies, some conclusions have been obtained. They are (1) the loss sensitivity and repeatability of SM fiber are better when compared to MM fiber in MOFS, and (2) the variation of pulse width of laser would only influent the signal-to-noise ratio and dynamic range, but has no contribution to loss sensitivity. Experimental results also show that loss of SM fiber highly depends on the wavelength of laser, but MM fiber has no such property. The loss of SM fiber between the wavelength of 1550 and 1310 nm is about the ratio of 6.5. Therefore, the experiments reported in this paper used a wavelength of 1310 nm to measure tensile strain and 1550 nm to measure compressive strain based on the above property of SM fiber, without changing the configuration of MOFS.     

镍磷合金镀层的摩擦磨损特性及其开发前景

本文分析了化学镀镍磷合金层的摩擦磨损试验结果,研究指出这一表面处理技术具有低的摩擦系数和高的耐磨性及硬度,又因沉积处理温度低而不存在变形,亦不影响零件原来的精度及粗糙度,因此宜于作为零件的最终表面处理。若应用于齿轮,凸轮等高副零件,前景十分乐观。最后从试样的磨损失重中估算出磨损系数和磨损减薄量以供作耐磨性设计的参考。     

胡萝卜饮料在工业生产过程中胡萝卜素稳定性的研究

胡萝卜素具有非常高的营养价值和疗效作用．报道了胡萝卜饮料在工业生产过程中胡萝卜素的稳定性，着重分析了热处理、打浆、酶处理、配料、均质、脱气、杀菌等过程中胡萝卜素的变化情况．     

卤化物晶体光纤的性质和损耗机理

在钟宏杰等利用直接成型法生长KCl和AgCl晶体光纤的基础上，采用理论计算和实验测量方法，研究了它们的光学性质和光损耗机理。计算和测量结果表明，光纤芯与包层及界面的光吸收和散射是产生损耗的主要原因，通过减少光纤宏观和微观缺陷，可将光纤损耗降低到原来的十分之一。     

双边截断型分布族参数的经验Bayes估计

在Linex损失函数下,讨论一类双边截断型分布族参数的经验Bayes（EB）估计问题,构造了参数的EB估计,在适当的条件下给出了该估计的收敛速度,最后给出例子,说明定理条件的合理性。     

多维线性模型均值矩阵的线性Minimax估计

本研究多维线性模型中均值矩阵在不同损失函数下的线性Ｍｉｎｉｍａｘ估计,得到了具体的表达式。     

乙醇在Mn薄膜／Rh（100）上吸附和分解的研究

应用高分辨电子能量损失谱（HREELS）和热脱附谱（TDS）,研究了Mn薄膜／Rh(100)上乙醇的吸附和分解,提出了表面吸附和分解的反应工,在300K时,蒸镀的Mn在清洁Rh(100)表面上以层层模式生长;在130－300K间,在25mLMn/Rh(100)表面上吸附20L乙醇的TDS结果与乙醇在Rh(100)表面上的结果一致在155K处,脱附出多层凝聚态吸附的乙醇;升温到255K,脱附出H2和CH4,继续升温,出现了与乙醇在R (100)表面上不一致的现象,在470K,同时出现了第2个H2和CH4的脱附峰,在500K,脱附极少量的CO;在950K附近,脱附出大量CO。     

通信用低损耗蜘蛛网结构包层空芯塑料布喇格光纤

提出并分析了利用蜘蛛网结构包层空芯布喇格光纤在0.65 μm~1.55 μm和200 μm ~500 μm波长范围得到低损耗传输的可能性.采用渐近转移矩阵公式所做的分析结果表明：这种光纤的传输损耗远低于构成光纤所用塑料的吸收损耗.在0.65 μm ~1.54 μm的可见至近红外波段,这种光纤结构可把构成光纤所用塑料的吸收损耗抑制为1/237 000,甚至可抑制为1/1 300 000;在200 μm ~500 μm的太赫兹波段,这种光纤结构可把构成光纤所用塑料的吸收损耗抑制为1/8 962,甚至可抑制为1/83 390.因此用便宜的塑料,可以在可见至太赫兹波段用这种光纤构成较长距离、较高带宽的光纤通信系统,并实现波分复用（WDM）.     

Experimental demonstration and cascadability analysis of a tunable optical buffer based on a re-circulating loop consisting of optical SSB modulator and FBG filter

We demonstrate a tunable optical buffer with variable time delays for label switching applications using an optical single sideband modulator in a fiber Bragg grating-filter loop. This optical buffer realizes payload storage with optional wavelength conversion function, providing flexibility in packet router design. Small sensitivity penalty is observed in our experiment after the payload circulating in the buffer loop three times. The cascadability of the tunable optical buffer is investigated. We provide analysis of the optical signal to noise ratio degradation due to accumulated amplified spontaneous emission noise, and the penalty caused by loss ripple and group delay ripple of the fiber Bragg grating.