InGaAs（P）分别限制应变单量子阱激光器的优化设计

针对较常用的ＩｎＧａＡｓ（Ｐ）分别限制应变单量子阱激光器，给出了为得到最大净增益的优化设计参数。对于激射波长为１．５５μｍ的无应变激光器，最佳的光限制层波长为１．２４μｍ，厚度为１００ｎｍ。当阱材料引入压缩应变后．由于价带的有效状态密度减小，量子阱激光器的微分增益变大，阱深的增大对增大线性增益的效果更加明显．所以最佳光限制层的波长将变短，为１．２０μｍ     

Synthesis of Single-Crystalline Silicon Nitride Nanobelts Via Catalyst-Assisted Pyrolysis of a Polysilazane

Recently, one-dimensional nanostructures have attracted extensive attention since they are potentially important for both applications and fundamental research. In this paper, we report the synthesis of ultra-long single crystal Si₃N₄ nanobelts via catalyst-assisted pyrolysis of polymeric precursors. The obtained products contain both α- and β-Si₃N₄ nanobelts, which are 50–100 nm in thickness, 400–1000 nm in width, and a few hundreds of micrometers to several millimeters in length. Different from previous techniques for synthesizing one-dimensional structures, the current nanobelts are synthesized through confined crystallization of an amorphous phase. A solid–liquid–gas–solid reaction/crystallization growth mechanism is proposed. The formation of nanobelts instead of nanowires is attributed to the anisotropy growth at an earlier stage.     

Superior integrated field emission cathode with ultralow turn-on field and high stability based on SiC nanocone arrays

Low turn-on field (E_to) and stable electron emission are two of key parameters for reliable application of field emission (FE) cathodes. In the present work, we developed a novel high-performance integrated field emission cathode based on well-aligned SiC nanocone arrays via an electrochemical etching approach. The etched SiC nanocone emitters and the underlying remaining SiC wafer are designed into a single-crystalline integrated architecture without interfaces, which favors cathodes with a sturdy configuration to resist Joule heat during long period electron emission process and structural failure caused by the existed strong electrostatic forces. Accordingly, the E_to of the integrated SiC cathode is reduced to 0.32 V/μm, which is the lowest value among all the previously reported SiC nanostructured emitters. In addition, the integrated cathode presented superior stability with an electron emission fluctuation of 3.3% over 10 h. This work provides a new perspective for designing and fabricating advanced FE cathodes for further promising applications in harsh working conditions with high performance.     

液体聚丁二烯橡胶在全钢巨型工程机械子午线轮胎胎侧胶中的应用

研究液体聚丁二烯橡胶（LPB）在全钢巨型工程机械子午线轮胎胎侧胶中的应用。结果表明：以LPB等量替代增粘树脂用于全钢巨型工程机械子午线轮胎胎侧胶中,混炼胶的加工安全性提高,硫化速度降低;硫化胶的生热减小,物理性能和耐老化性能提高,胎侧胶的整体性能得到改善。     

水力机组振动监测与故障诊断

针对水力机组运行过程中因振 动而引起故障并造成经济损失这一问题，开发了一套新型的振动监测及故障诊断系统，它以 工业PC 机为主体，与摆度、振动传感器及有关功能模块和信号预处理器共同组成机组振动 在线监测分析系统。利用该系统对机组振动的周期性监测，能够在线监测机组缺陷的缓慢变 化过程，为视情检修提供良好的依据，同时也为机组运行调度提供可靠的信息。介绍了该系 统的硬件及软件组成、原理及功能，并结合实例运用小波分析与傅里叶分析相结合的信号分 析方法，对机组故障进行了分析诊断，找出了故障原因。     

8×8 MEMS光开关阵列的制作

采用MEMS技术制作了静电驱动的扭臂结构8×8光开关阵列,主要包括上下电极的制作.利用硅在KOH溶液中各向异性腐蚀特性及(110)硅的结晶学特点,在(110)硅片上制作出8×8光开关微反射镜上电极阵列,考虑到在腐蚀时微反射镜有很大的侧蚀,对开关结构进行了调整.在偏一定角度的(111)硅片上制作了倾斜的下电极.整个开关制作工艺简单,成本低.开关寿命大于1000万次,开关时间小于10ms.     

Polygonal Single-Crystal Aluminum Borate Microtubes

In this paper we report the synthesis of polygonal single-crystal aluminum borate microtubes by the direct calcination of alumina and boron nitride powders in air. The diameters of the obtained tubes vary between 1 and 15 μm; and the lengths are in the range of tens to hundreds of micrometers. The cross-sections of the microtubes are in the shapes of rectangular, hexagonal, and quasi-circle. A new solid–liquid–solid growth mechanism was proposed to account for the formation of microtubes instead of whiskers.     

Perfect Single-Crystal Alumina Microspheres

We report the synthesis of perfect single-crystal Al₂O₃ microspheres via direct thermal decomposition of aluminum isopropoxide in air without any template or catalyst. The obtained microspheres were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and selective area electron diffraction. The results suggested that the formation of the spheres can be attributed to a transition from polycrystalline to single-crystalline symmetry during high-temperature annealing. The obtained microspheres could be useful for many applications such as lubricants and polishing mediums.