杨树的栽培

杨树是我国重要的速生树种之一.在安徽,杨树已经成为退耕还林、防护林建设、绿色长廓等工程以及四旁绿化的主要栽培树种,栽植面积愈来愈大,特别是2002年以来,各地结合退耕还林工程建设,把杨树作为一项产业和农业增效、农民增收的重点工作来抓,杨树造林面积猛增,两年全省新造杨树面积达25万公顷,占同期全省造林总面积的48%,涌现出一批通过杨树生产和加工走上致富路的千元村和万元户.为了进一步搞好杨树生产,现将杨树人工栽培和管理技术介绍如下.     

L—天冬氨酸微生物电极的研制

本文以大肠杆菌为天冬氨酸脱氨反应的酶源，采用氨气酶电极为基础电极研制成Ｌ－天冬氨酸微生物电极。对细菌培养条件，固定方法及电极工作条件等进行了研究，测定Ｌ－天冬的氨酸Ｅ－１ｇＣ曲线斜率为５５ｍＶ，线性范围为６．０％×１０＾－４～８．０×１０＾－３ｍｏｌ／Ｌ，寿命可达１０天。     

陕西省汉阴县北部金矿田地质特征

陕西省汉阴县北部志留系岩金矿田是陕西省矿产资源规划优选的贵金属矿产资源主要勘查评价区带。本次主要研究工作区以汉阴县北部铁佛-汉滨区流芳金矿带为主,通过已有资料的分析研究、野外调查、总结该金矿田的地质特征,为加快该岩金矿田评价提供支持。     

三峡电站主厂房分层空调冬季工况模型试验

建立三峡电站主厂房发电机层标准机组段分层空调的试验模型。在确保分层效果的基础上，对该模型冬季供暖工况进行温度场和速度场的实测，就2种不同的送风口型式及同一送风口型式3种不同送风方式对模型工作区空气分布特性的影响作了初步分析，在试验条件下确定出了最佳的送风口型式及送风方式；同时，在送风口型式及送风方式不变的情况下，改变送风温度以观测其对工作区温度场的影响，从而为后续的分层空调模型试验提供了必要的技术数据，亦为同类工程建设提供了一些可供参考的结论。     

Sc(Ⅲ)催化胺对邻亚甲基苯醌氮杂迈克尔加成反应合成贝蒂碱衍生物

邻亚甲基苯醌化合物是一类非常活泼和重要的中间体,被广泛应用于天然产物和药物化学中.以2-[羟基(苯基)甲基]苯酚类化合物和胺为原料,1,2-二氯乙烷为溶剂,在Sc(III)促进下原位生成邻亚甲基苯醌,并发生氮杂迈克尔加成反应合成贝蒂碱衍生物.反应在封管条件下90℃搅拌4 h完成,以76%～96%的产率得到目标产物.     

Integrated optoelectronic chip pair for transmitting and receiving optical signals simultaneously

An integrated optoelectronic chip pair, which can transmit and receive optical signals simultaneously, is proposed in this Letter. The design and optimization of its key structure, the vertical cavity surface emitting laser's distributed Bragg reflector, are presented. Analysis is also done for its influence on the integrated chip's performance. Moreover, the chip pair's performance under dynamic conditions is analyzed. Their 3 dB modulation bandwidths are higher than 10 GHz, and their 3 dB photo-response bandwidths are around 23 GHz. Their applications will further improve the performances of the optical interconnects.     

Nd:YAG激光器的热透镜效应及其对激光输出的影响

对Nd：YAG激光器的热透镜效应进行了分析，给出了实验测量动态热效应的方法．利用矩阵光学的方法，分析了热透镜效应对激光输出功率和光束质量的影响，并计算了两种谐振腔参数下的束腰宽度ωo、远场发散角θo和模体积V随热焦距f的变化情况．     

局部放电在线监测中的抗干扰技术

抑制干扰是在线监测电力设备局部放电的关键技术。文中论述了所研制的各种适用于在线监测电力设备局部放电的抗干扰技术，包括组合式滤波器、数字滤波技术、差动平衡系统和脉冲极性鉴别系统。指出了它们在在线监测局部放电中的实际效果。首次提出并研制了适用于在线监测局部放电的新的脉冲极性鉴别系统及其鉴别判据。最后提出了适用于在线监测电力设备局部放电的抗干扰系统。     

On-Line Partial Discharge Monitoring and Diagnostic System for Power Transformer

This paper introduces a computerized on-line partial discharge （PD） monitoring and diagnostic system for transformers. The system, which is already in use in a power station, uses wide-band active transducers and a data acquisition unit with modularized and exchangeable components. The system software is a power equipment monitoring and diagnostic system, which is based on the component object model, and was developed for monitoring multiple parameters in multiple power supply systems. The statistical characteristics of PDs in power transformers were studied using 7 experimental models for simulating PDs in transformers and 3 models for simulating interfering discharges in air. The discharge features were analyzed using a 3-D pattern chart with a three-layer back-propagation artificial neural network used to recognize the patterns. The results show that PDs in air and oil can be distinguished. The model can be used for interference rejection on-line monitoring of partial discharge in transformers.