Analysis of S-SEED''s characteristics in optical switch

This article introduces the basic structure of a symmetric self-electrooptic effect device （S-SEED）, and applies the Kirchoff＇ s current law and a purely equivalent capacitive model, to analyze S-SEED＇s switch characteristics. Linear approximation and N-segment approximation are utilized to obtain S-SEED＇s voltage-time （V-T） and characteristics. Theoretical analysis is verified by simulations, and the results demonstrate that the precision of S-SEED＇s switch time can satisfy the requirement in applications with linear approximation. Moreover, the simulations compare S-SEED＇s switch characteristics with different input powers and input contrast ratios, which reveal that increasing input contrast ratio is an effective way to improve S-SEED＇s switch characteristics.     

浅谈光缆生产中的吹干方式与能效利用

针对光缆生产中对光纤套管、填充绳及护套生产工序频繁使用的吹干工艺要求，大流量的压缩空气在能效不充分的利用中流失问题，探讨对吹干器的工作原理和改进方案，以及生产中的效果和能耗的控制。     

薯秧倒栽增产

笔者在同等条件下试验对比薯秧倒栽比顺栽可提高产量1倍以上。倒栽的薯苗比顺栽的生长缓慢．约需7天时间叶腋间长出新芽，以后慢慢形成主茎，由于茎中输导组织输送根部吸收的水分及有机养料的方向逆转．其输送速度减慢．     

Spin Dependent Hopping in Ti Doped La0.67 Ca0.33 MnO3

A systematic investigation of the magnetic and transport properties of Ti doped La0.67Ca0.33MnO3 was reported. The Ti substitution for Mn ions results in a reduction in ferromagnetism and conductivity. The metal-insulator transition temperature is close to Curie temperature which decreases from 274 to 82 K as x increases from 0 to 0.17. The most important effect of Ti doping is to introduce spin clusters in the samples due to the distortion of local lattice and the inhomogeneous magnetic structure induced primarily by the random distribution of Mn ions. A maximum magnetoresistance ratio as large as 90% in 1 T at 122 K was obtained for the sample with x =0. 055, which is four times larger than that obtained for LCMO sample at 272 K. There is a remarkable field-history dependent MR in the cooling process for the doped samples while such phenomenon disappears in the warming run. The resistivity follows well the variable range hopping behavior in paramagnetic state. Both the size effect and spin dependent hopping of carriers between the spin clusters should be considered in this system.     

网络制胜

对于一个企业来说，有效地利用网络是十分重要的。网络有一种“乘数效应”，它可以帮助企业克服自身的不足和弱点，赢得必要的优势。