Sagnac fiber interferometer with the population grating for fiber Bragg grating dynamic strain sensing

A Sagnac fiber interferometer with the population grating formed in saturable erbium-doped fiber (EDF) for fiber Bragg grating (FBG) dynamic strain sensing is proposed. In this configuration, a semiconductor optical amplifier (SOA)-based fiber ring laser with an FBG reflector is employed in the sensing part and a Sagnac interferometer based on transient two-wave mixing (TWM) via dynamic population gratings in single-mode polarization maintaining erbium-doped fiber (PM-EDF) is used in this detecting part. Experimental results show that the Sagnac fiber interferometer detection system can stably respond to dynamic strains at high frequencies. As an example of application, the response of the sensor system to continuous sinusoidal ultrasonic signals is presented. The proposed simple and robust configuration has an all-fiber design based on commercially available elements, which makes it promising for applications in fiber optic ultrasonic sensors.     

考虑桩-土-结构动力相互作用时高层建筑风致振动的响应计算

本文推导了考虑桩土结构动力相互作用时高层建筑在脉动风荷载作用下的运动方程。然后根据国家规范提供的参数及风洞试验得到的形状系数,推导出脉动风速及风压之间的关系,求出脉动风荷载的时程。利用该荷载对某超高层建筑的动力响应进行了计算。计算结果表明：桩土结构动力相互作用对高层建筑的风致振动响应的影响是明显的,应当引起重视。     

超声波技术在真丝印花织物退浆中的应用

针对真丝印花织物退浆水洗工艺耗能耗水较大的缺点,将超声波技术用于真丝印花织物的退浆水洗工艺.通过与常规水洗的退浆效果的比较,对超声波退浆水洗的可行性进行了评价;改变超声波退浆水洗的功率、时间和温度,研究影响超声波退浆水洗效果的因素.结果表明:超声波退浆水洗效果明显优于常规水洗,而且节能减耗.     

浅探企业任期经济责任审计的内容

企业领导人是企业管理的第一设计者 ,对于其任期经济责任的审计 ,既要确认企业组织的资产、负债、损益的真实、合法、有效性 ,同时又要确认任期被审人的经营责任、管理责任、财经法纪责任、社会责任 ;既要确认任期经济指标完成情况 ,更不能忽视组织的可持续发展。     

2,6-二氟-4-羟基苯甲腈的合成

实验以3,5-二氟苯胺为原料,经溴化、重氮化水解和氰化合成2,6-二氟-4-羟基苯甲腈。重氮化水解步骤的最佳反应条件为:n(4-溴-3,5-二氟苯胺):n(水)=1:30,n(4-溴-3,5-二氟苯胺):n(磷酸)=1:6,n(4-溴-3,5-二氟苯胺):n(五水硫酸铜)=1:1.0。该法生产成本低廉,反应条件温和,适合于工业化生产。产物含量为99%,摩尔产率为21.7%,其结构通过MS和~1H MR进行论文验证。