IDR双汽提尿素装置现状及控制设想

本文对IDR尿素装置的目前生产情况进行了统计和分析。同时根据观察、统计和测试,对某些问题提出思路。     

用PSD检测长直导轨准直度

介绍了用光电位置传感器（ＰＳＤ）检测长直导轨的原理和方法。利用ＰＳＤ作为位置传感的检测系统能实时、连续地对被测件三维空间准直度进行检测，更好地解决了以往移动桥板分段测量、人工读数（数格）局部检测的方法存在的问题。     

低含量Pr3+掺杂WO3的制备及其光催化分解水析氧活性

采用低温固相反应法制备低含量Pr^3＋（0.05%,质量分数）掺杂的WO3催化材料,采用XRD、XPS和DRS对样品进行表征和分析,考察催化剂在电子接受体Fe3＋溶液体系下的光催化分解水制氧活性。结果表明,0.05%Pr^3＋掺杂可以使WO3样品的光谱响应范围向可见光区拓展。XPS分析表明,Pr^3＋掺杂可以导致催化剂样品表面氧缺位增加。在可见光辐射下光催化分解水制氧的实验中,0.05% Pr^3＋掺杂WO3样品的光催化析氧速率高达196.64μmol/（L.h）,是未掺杂WO3的2倍。     

伊利石在铝酸钠溶液中的反应脱硅过程研究

为了更清楚地了解伊利石在拜耳法溶出过程中的反应行为，本文对伊利石在合成铝酸钠溶液中的溶出动力学进行了研究，测得其活化能为114，73kJ/mol。并研究了溶液苛性碱浓度对伊利石的反应速率的影响；添加石灰可以有效的增加伊利石的反应率，提高脱硅效率。为拜耳法生产氧化铝的脱硅过程及防止结疤提供理论依据。     

铝酸钠(钾)溶液种分过程的分解率和粒度分布

采用等温间歇式反应器研究了纯铝酸钠和铝酸钾溶液在种分过程的分解率、粒度分布(PSD)的变化规律,同时对分解产品进行了XRD、SEM和TG/DTG分析.结果表明,在相同的分解条件下,铝酸钾溶液的分解率大于铝酸钠溶液;铝酸钠和铝酸钾溶液中颗粒的粒度分布随时间变化具有显著差异;产品的XRD显示,分解过程中铝酸钾比铝酸钠溶液中的晶体结晶度完整,但产品的TG/DTG曲线却没有明显的差别.对于不同ακ值的铝酸钠和铝酸钾溶液,这些差异是相似的.铝酸钾与铝酸钠溶液在种分过程中的成核速率不同可能是引起分解率和粒度分布产生差异的原因.     

薄壁金刚石钻头的研制和在电熔锆刚玉耐火材料中的应用

电熔锆刚玉砖具有高硬度、耐高温、耐磨损、抗腐蚀等特点,因而成为玻璃熔窑的关键筑炉材料.文章通过复合电镀方法研制和生产薄壁金刚石钻头.在研制过程中,对金刚石钻头的胎体配方进行了优化,确定了电镀工艺参数,分析了金刚石参数等对钻进过程的影响,采用混目金刚石扩大了钻头的适用范围,提高了钻头的自锐性.研制的电镀薄壁金刚石钻头用于钻进锆刚玉砖耐火材料,其平均使用寿命达到6m,钻进时效为1.5m.使用结果表明胎体配方、工艺流程和电镀参数是合理的,电镀金刚石薄壁钻头是最适合钻进电熔锆刚玉砖的金刚石工具,加工后的锆刚玉砖具有精确的几何形状和高光洁度的表面.     

Dissolution mechanism and solubility of hemimorphite in NH3-(NH4)2SO4-H2O system at 298.15 K简

The dissolution mechanism of hemimorphite in NH3-（NH4）2SO4-H2O system at 298.15 K was investigated by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS） analysis. The results show that hemimorphite is soluble in NH3-（NH4）2SO4-H2O system and its residue exists in the form of an amorphous SiO2 layer on the hemimorphite surface. The XPS data also indicate that the Si 2p3/2 and O ls spectra of the hemimorphite are broadened and shift to higher binding energies and their binding energies are closer to silica with an increase of total ammonia and time. Solubility of hemimorphite in NH3-（NH4）2SO4-H2O system was measured by means of isothermal solution method at 298.15 K based on the study of the dissolution mechanism of hemimorphite. The results show that the solubility of zinc in solution increases firstly and then decreases with the increase of cr（NH3） （total ammonia concentration） at different NH3/NH4^＋ ratios. The solubility of silicon in solution decreases from 0.0334 mol/kg in ct（NH3）-4.1245 mol/kg NH3-（NH4）2SO4-H2O solution to 0.0046 mol/kg in cT（NH3）=7.6035 mol/kg NH3-（NH4）2SO4-H2O solution.     

Synthesis and characterization of triclinic structural LiVPO4F as possible 4.2 V cathode materials for lithium ion batteries

A potential 4.2 V cathode material LiVPO4F for lithium batteries was prepared by two-step reaction method based on a carbon-thermal reduction （CTR） process. Firstly, V2O5, NH4H2PO4 and acetylene black are reacted under an Ar atmosphere to yield VPO4. The transition-metal reduction is facilitated by the CTR based on C→CO transition. These CTR conditions favor stabilization of the vanadium as V^3＋ as well as leaving residual carbon, which is useful in the subsequent electrode processing. Secondly, VPO4 reacts with ElF to yield LiVPO4F product. The property of the LiVPO4F was investigated by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electrochemical measurement. XRD studies show that LiVPO4F synthesized has triclinic structure（space group p I ）, isostructural with the naturally occurring mineral tavorite, EiFePO4-OH. SEM image exhibits that the particle size is about 2μm together with homogenous distribution. Electrochemical test shows that the initial discharge capacity of LiVPO4F powder is 119 mA·h/g at the rate of 0.2C with an average discharge voltage of 4.2V （vs Ei/Li^＋）, and the capacity retains 89 mA·h/g after 30 cycles.     

几种铝化合物的热力学性质

结合作者的量热测定结果和前人的工作，研究了氧化铝工业中最常见的几种铝化合物如α－Ａｌ２Ｏ３，γ－Ａｌ２Ｏ３，三水铝石一水软铝石和一水硬铝石的基本热力学性质：标准生成焓、标准熵、标准生成Ｇｉｂｂｓ自由能和热容，得到了可靠，自洽的结果。     

锂离子电池电解液过充添加剂的行为

制备了3种1 mol/L LiPF6电解液,溶剂组成分别为:1)碳酸乙烯酯,碳酸二甲酯和碳酸甲乙酯;2)碳酸乙烯酯,碳酸二甲酯,碳酸甲乙酯和4%联苯;3)碳酸乙烯酯,碳酸二甲酯,碳酸甲乙酯和4%环己基苯.采用线性电压扫描法、锂循环效率法、锂离子电池的循环性能法和3 C倍率过充的方法测试了联苯与环己基苯电解液过充添加剂的行为.结果表明:环己基苯是一种较实用的锂离子电池电解液过充添加剂,环己基苯的电化学稳定性比联苯的高,环已基苯的氧化电势为4.72 V(vs Li/Li ),联苯的为4.54 V(vs Li/Li );以1 mA电流循环20次后,联苯的铂电极锂循环效率为15.7%,环己基苯的为59.3%;锂离子电池以1 C循环150次后,环己基苯的容量保持率为88%,联苯的为76.3%.环己基苯与联苯添加剂都改善了锂离子电池的耐过充性能,且两者的效果十分接近.