[H3NNH3]2K2MnMo9O32·(NH3)·3H2O: synthesis and crystal structure determination of a novel heteropolyoxometallate related to the Waugh structure

A novel heteropolyoxometallate with the formula [H₃NNH₃]₂K₂MnMo₉O₃₂·(NH₃)·3H₂O has been prepared in water solution. The crystal structure of the title compound was determined by the single-crystal method. This new mixed metal anionic complex crystallizes in the rhombohedral space group R3 (No. 146) with a=b=15.873(5), c=12.344(6) Å, γ=120°. The disordered structure contains three molecules in the unit cell. Full-matrix least-squares refinements of the title complex yielded final reliability (R) factors of 0.0356 (Rw=0.0868) with a goodness-of-fit (GOF, Σ₂) value of 1.099 based on 1430 [I>2σ(I)] observed reflections. All Mo and Mn atoms are six-coordinated octahedrally to form a Mn-centered cage with a Mo₉O₃₂ group as the framework.     

精铟中铊的氯化脱除

探索了采用NH4Cl的甘油溶液熔炼除铊来代替传统除铊的方法。研究表明 :NH4Cl的甘油溶液浓度为15 % (质量分数 ) ,熔炼时间为 2 0min ,熔炼温度为 2 2 0℃时 ,可除去精铟中 6 0 %～ 70 %的铊 ,铊含量降低 4 0 μg/g左右。该方法具有纯化效果好、操作简单、能缩短工艺流程、避免了有毒物质的使用的优点。     

硼含量对FeCrMoSiB合金急冷态及退火态组织与性能的影响

本文研究了不同硼含量下FeCrMoSiB单辊急冷带及950℃退火带的显微组织及硬度和脆性。发现在B≤17％范围内,硼含量的增加提高非晶形成能力及抗晶化能力,但同时也增加其脆化倾向,非晶内部存在成分与结构的不均匀性。当B=20％时,非晶形成能力急剧下降,生成与(Cr,Fe)_2B结构相近的亚稳相。退火带由硼化物与α-Fe晶粒组成。硼化物有M_3B_2和(Cr,Fe)_2B两种,其中(Cr,Fe)_2B数量随硼含量线性增加而M_3B_2数量基本不变。     

长江中下游鹅头型汊道演变规律的分析

鹅头型分汊是长江中下游城陵机至江阴分汊河段中形最复杂、放宽率最大，分汊数量多，占汊道总长度最大（达40％）的一种分汊形式。其演变主要于本身的河床形态，边界条件及水流条件的变化，基本上遵循新生汊道－产生、扩大、平移、衰亡而完成它一个完整的演变周期。由于汊道的弯曲引起滩地的大面积坍失，主流线大幅度摆动，各汊道水沙的重新分配及纵横剖面的调整，是一种最不稳定的分汊型式，对鹅头型分汊河道的形成条件及演变特征的研究是制订相应的规划整治措施，稳定河势，使其朝着有利的方向发展的前提条件，也是实际工程迫切要求解决的问题。     

实施SY/T6143──1996标准的说明

在国家石油天然气行业标准SY/T6143—1996“天然气流量的标准孔板计量方法”颁布后，该标准代替SY104—83标准，凡使用标准孔板测量天然气流量均应按该标准实施。由于目前现场绝大多数的计量点配用的二次仪表为CW—430双波纹差压流量计、水银温度加求积仅、计算器并采用人工求积计算，要严格按该标准实施有一定难度，本文说明了我国目前天然气计量现场标准孔板配用的两种二次仪表的三种计算处理办法，特别重点介绍配用CW－430双波纹差压流量计水银温度计加求积仅，计算器的室内、现场的变通化简处理办法。     

The Investigation on the Microstructure of Metallurgical Molten Slags and the Foundation of the Primary Cluster Theory

This paper presents the characteristics of the properties of metallurgical molten slags based on the bond structure or the existence of certain ion clusters. Some experimental and theoretical approaches were adopted in the investigation. Two sets of high temperature Raman spectroscopy (HTRS) were established at Shanghai University; both can be successfully operated at 2000K or higher. One of them combines the accumulated time resolution together with the spatial resolution, and it is designed for both ultraviolet (UV) and visible (VIS) light. The SiOT model uses 5 kinds of Si‐O tetrahedra (Q_n) as microsturctural units. In this model, each sample contains 250000 or more tetrahedra. The calculation using a GF matrix and electro‐optical parameter (EOP) methods were performed for every tetrahedron one by one to determine the partial Raman spectra of Q_n. Then the spectra were integrated to obtain an envelope of the sample. In addition to the SiOT model, a CEMS model was also developed to link the ion cluster structure and the thermodynamic properties at equilibrium (as mixing free energy).     

300 MHz CATV信号光纤传输系统设计

本文介绍一个与现有300 MHz CATV电缆传输系统兼容的光缆传输系统,无中继距离可达30km,CNR可达43dB。文中还对国产LD—PIN器件提出了传输模拟信号的特殊要求。     

液氯钢瓶失效分析

本文在充分调研和试验基础上,对几十个判废的液氯钢瓶进行了综合分析,并结合试验测试数据和理论计算,对液氯钢瓶的失效方式进行了分类总结,对判废标准做了若干探讨,为钢瓶的安全、合理使用提供了依据。     

基于MAX1873锂电充电控制器的双电源供电系统设计

目前大多数据采集系统采用220V交流电源供电，而在实时性要求高的场合则采用交流电源作为主电源并且蓄电池作为备用电源的双电源系统进行供电，以防止由于交流电源的突然断开而造成数据采集系统的数据丢失。针对220V交流电源供电系统以及交直流双电源供电系统中存在的问题和缺陷，介绍了多节锂电充电控制器MAX1873的特点和充电控制方法，以及利用MAX1873构成的锂电市电双电源供电系统的详细设计方法和设计调试中应注意的问题。