PECVD法Tisi2薄膜的制备工艺研究

本文利用PECVD低温淀积台进行TiSi_2薄膜的制备。采用X射线衍射、俄歇分析和扫描电镜等分析手段,对所制备的TiSi_2薄膜及其氧化特性、多层膜结构和刻蚀特性进行了全面的测试分析,证明采用PECVD方法制备TiSi_2薄膜的工艺是完全可行的。     

混凝土聚羧酸减水剂引发体系的研究

以异戊烯醇聚氧乙烯醚(TPEG)、丙烯酸(AA)为聚合单体,在过氧化氢(H_2O_2)-酒石酸(TA)氧化还原引发体系引发下,以巯基乙酸(TGA)为链转移剂,通过水溶液聚合制备高性能混凝土聚羧酸减水剂.实验结果表明,H_2O_2-TA氧化还原引发体系制备混凝土聚羧酸减水剂的最佳工艺为:反应温度为30℃,n(H_2O_2):n(TA)为2.6:1,H_2O_2的用量为TPEG质量的0.6%,TGA的用量为TPEG质量的0.7%,AA用量为TPEG质量的13%.该工艺制备的聚羧酸减水剂具有较优的分散性和分散保持性.     

Ni-La／Al2O3催化剂上催化裂化轻汽油的选择性加氢

以γ-Al_2O_3为载体,制备了Ni-La/Al_2O_3双金属选择性加氢催化剂,并用于催化裂化轻汽油的选择性加氢反应。考察了工艺条件对选择性加氢反应的影响。结果表明,二烯烃转化率和单烯选择性随着反应温度的升高而增加,但超过75℃二烯烃转化率已无明显增加,且单烯选择性下降;随着反应压力的升高,二烯转化率提高,但单烯损失较大;二烯烃转化率和单烯选择性随着空速的提高分别呈现下降和上升的趋势;氢气量应该严格控制,否则不仅造成浪费,还会使单烯损失增大。最佳的反应条件:温度75℃、压力1.0MPa、空速10h~(-1)、氢油比为8。在该条件下,催化裂化轻汽油中二烯烃转化率可达到97.8％,单烯烃损失小于2％。表明该催化剂具有良好的加氢活性和选择性,有很好的研究开发前景。     

利用反应溅射沉积在γ—Al_2O_3粉末上制备TiO_x/γ—A1_2O_3催化剂

在微波ECR等离子体中,用平面磁控溅射靶,在γ-Al_2O_2粉末上沉积了TiO_x膜.为了使γ-Al_2O_3颗粒能被TiO_x均匀覆盖,使用了振荡器.文中详细地介绍了实验装置.甲烷转化率,C_2和C_2H_2的产额与选择性的对比结果表明:这种方法制备的催化剂优于传统的化学方法所制备的催化剂,同时也表明振荡器的作用明显.     

正丁烷氧化制顺丁烯二酸酐钒、磷、氧体系催化剂的研究

通过两种不同的方法制备了两个系列的钒、磷、氧体系催化剂,对这两个系列的催化剂在微分反应器中的活性、选择性进行了评价,并且通过XRD、IR及SEM等方法对它们的相结构、表面酸性进行了研究。结果说明:(VO)_2P_2O_7是催化剂的活性相,V_2O_5,H_3PO_4·1/2H_2O是催化剂的有害相。催化剂表面Lewis酸中心为该催化剂的反应活性中心。     

Si-Al-Y Co-deposition Coatings Prepared on Ti-Al Alloy for Enhanced High Temperature Oxidation Resistance

Si-Al-Y co-deposition coatings were prepared on Ti-Al alloy by pack cementation processes at 1 050 ℃ for 4 h with different halide activators in the packs for enhancing the high temperature oxidation resistance of Ti-Al alloy. The structure, constituent phases, formation process and oxidation behavior of the coatings were investigated. The experimental results showed that the coatings prepared respectively with NaF and NH_4Cl as activators were composed of a(Ti, X)_5Si_4,(Ti, X)_5Si_3(X represents Nb and Cr), and TiSi_2 outer layer, a TiAl_2 inner layer and an Al-rich interdiffusion zone. However, the constituent phases changed into TiSi_2 in the outer layer and(Ti, X)_5Si_4 and(Ti, X)_5Si_3 phases were observed in the middle layer of the coating prepared with AlCl_3·6H_2O activator. Among the halide activators studied, the coating prepared with AlCl_3·6H_2O was thicker and denser, which is the only suitable activator for pack Si-Al-Y co-deposition coatings on a Ti-Al alloy. The oxidation results show that the coating can protect the Ti-Al alloy from oxidation at 1000 ℃ in air for at least 80 h. The excellent oxidation resistance of the coating is attributed to the formation of a dense scale mainly consisted of TiO_2, SiO_2 and Al_2O_3.     

2-(4-吡啶基)-4,5-二氢恶唑的催化合成

采用浸渍法制备了分子筛负载氧氯化锆催化剂ZrOCl_2·8H_2O/H-BEA、ZrOCl_2·8H_2O/H-USY、ZrOCl_2·8H_2O/H-ZSM-5和ZrOCl_2·8H_2O/H-MCM-41,并在无溶剂条件下考察了它们催化4-氰基吡啶与乙醇胺缩合反应合成2-(4-吡啶基)-4,5-二氢恶唑的性能.结果表明:这些催化剂都表现出较高的催化活性,活性主要源于ZrOCl_2·8H_2O,同时也受载体比表面积和酸性位数量影响,其中ZrOCl_2·8H_2O/H-MCM-41的活性最高.在优化的工艺条件下,10%ZrOCl_2·8H_2O/H-MCM-41催化剂上,催化剂用量为反应原料质量的10%、4-氰基吡啶与乙醇胺摩尔比为1:2、温度为110℃下反应为180 min,2-(4-吡啶基)-4,5-二氢恶唑的产率达到98.4%.     

真空定向凝固对钛硅合金相分离及晶体生长的影响

Ti-85wt.%Si合金熔体通过定向凝固后成功地实现了Si相的分离和TiSi_2晶体的定向生长.研究发现,定向凝固下拉速度为15μm/s时,铸锭的分离界面呈包裹式分布,而3μm/s时铸锭的分离界面横向分布在铸锭的中下部;当下拉速度为3μm/s时,TiSi_2晶粒出现层状结构并且沿某一确定方向生长,并且随着定向凝固的进行,富集层厚度逐渐增加,导致铸锭底部散热能力比侧壁散热能力弱,导致沿铸锭侧壁温度梯度大于沿铸锭底部的梯度,此时TiSi_2将在侧壁形核并沿纵向温度生长,由于侧壁晶粒生长速度大于底部晶粒生长速度,使得分离界面出现弧形结构.当下拉速为3μm/s时获得铸锭的富Si层中Si的质量分数最大,为79.9%.     

“氧化铁薄膜敏感材料”通过技术鉴定

该课题是机电部电科院预研项目,采用PECVD法和APCVD法分别研制出性能优良的氧化铁酒敏材料和烟敏材料,与会专家们一致认为:1.采用了新的制备方法,改变了过去采用的烧结制备方法,因而有工艺简单、重复性好、适于批量生产、易与集成电路工艺兼容等特点;2.用PECVD法制备的酒敏材料灵敏度很高、选择性好、响应恢复时     

H_3PW_(12)O_(40)/TiO_2复合分子印迹材料的制备及光催化性能

因TiO_2降解污染物不具有选择性,因此利用分子印迹技术加以改性,采用溶胶-凝胶法制备了H_3PW_(12)O_(40)/TiO_2复合分子印迹催化剂。利用XRD、TEM、PC对其进行了表征,并探讨了其对DBP和竞争污染物PNP的光催化活性和选择性能。结果表明:改性后复合材料晶型没有改变,且分散性较好,光生电子和空穴分离效率较高。当DBP:H_3PW_(12)O_(40)/TiO_2=1:7时催化剂的光催化活性最好,对目标分子DBP的降解率最高可达95%;且在竞争污染物PNP与目标分子DBP同时存在的情况下,对目标分子DBP有较高的选择性吸附和选择性降解。     

UV/Fenton氧化法处理硝基苯废水的试验研究

目的研究UV／Fenton氧化法对难降解有机物硝基苯的氧化能力，确定UV／Wenton氧化法处理硝基苯处理废水的工艺条件．方法以自配硝基苯水样为处理对象，采用自制光反应器，通过试验研究分析H2O2投加量、Fe^2＋质量浓度、反应时间、pH值、硝基苯初始质量浓度等对UV／Fenton氧化法处理硝基苯废水处理效果的影响．结果实验研究结果表明，UV／Fenton氧化法对硝基苯有较高的去除率和反应速率，硝基苯的去除率可达到95％．H2O2投加量、Fe^2＋质量浓度、反应时间、pH值和硝基苯初始质量浓度对处理效果均有较大影响．结论硝基苯的质量浓度在不大于200mg／L时，UV／Fenton法能够有效去除硝基苯，最佳反应条件为：H2O2倍数为1．5左右，Fe^2＋与H2O2的摩尔比为1：30。pH值为4左右，反应时间为50min．     

Effects of Different Electrolytes on Stress Corrosion Properties of 2A12 Aluminum Alloy

The stress corrosion cracking (SCC) behaviors of 2A12 aluminum alloy after annealing treatment were studied by slow strain rate testing (SSRT),electrochemical polarization measurement,scanning electron microscope (SEM),energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM).Various concentrations of NaCl,H_2SO_(4 ) and HCl aqueous solution were prepared to act as the corrosive solution.The experimental results show that regarding the SCC,2A12 alloy performs best in NaCl solution but worst in HCl solution and intermediately between the above mentioned two cases in H_2SO_4 solution.For the SSRT carried out in room temperature,there is a higher decrease in elongation without large strength loss for the alloy immersed in NaCl solution.With the test conducted in H_2SO_4 solution,there is a higher strength loss and a relatively less loss of elongation compared to the one immersed in NaCl solution.With the test conducted in HCl solution,there is a relativel level loss of strength and elongation compared to either result carried out in NaCl solution or H_2SO_4 solution.     

Fenton氧化与吸附法联合处理焦化废水的研究

目的为了寻求一种行之有效的焦化废水处理新技术．方法利用Fenton氧化预处理联合活性炭吸附后续处理，以焦化废水的COD为考察指标，通过研究H2O2投加量、pH值、反应时间、[Fe^2＋]／[H2O2]（摩尔比）等因素对Fenton氧化预处理阶段处理效果的影响，确定Fenton氧化预处理阶段的操作条件；通过研究活性炭投加量、活性炭吸附时间、pH值等因素对后续活性炭吸附阶段处理效果的影响，确定活性炭吸附阶段的操作条件．结果实验表明，Fenton氧化-活性炭吸附联合工艺的最佳操作条件为：先在H2O2投加量为158mmol／L，[Fe^2＋]／[H2O2]=1：10，初始pH=3的条件下Fenton氧化预处理30min，然后投加1g／L活性炭吸附处理30min．结论在最佳操作条件下，Fenton氧化-活性炭吸附联合工艺处理焦化废水取得了良好的效果，处理后焦化废水COD由1935mg／L降为46．4mg／L，去除率达到97．6％，为该工艺的工业化应用提供了实验依据，同时对其他工业废水的处理具有借鉴意义．     

2,5-二甲氧基-4-氯苯胺的制备研究

探讨了乙醇和水的混合介质中,通过铁粉还原２,５－二甲氧基－４－氯硝基苯制备２,５－二甲氧基－４－氯苯胺的反应条件,即硝基物与铁粉的摩尔比、硝基物与冰醋酸的摩尔比、溶剂用量、电解质的种类及硝基物与电解质的摩尔比等条件与对还原物的影响,最后确定了２,５－二甲氧基－４－氯苯胺的最佳制备条件。     

溶胶凝胶法制备氧化亚铜薄膜及其工艺条件

以单质锂、无水甲醇和氯化铜为原料,葡萄糖为还原剂,醋酸为络合剂,采用溶胶 凝胶法在玻璃基片上制备Cu2O薄膜,并确定了制备的工艺条件:CH3OH及CuCl2·2H2O为原材料,C6H12O6·H2O为还原剂,CH3COOH为络合剂。通过X射线衍射仪、紫外 可见分光光度计和扫描电镜等分析和表征,确定了影响Cu2O薄膜性质的因素。结果表明:用溶胶 凝胶法可以制备具有良好性能的Cu2O薄膜。     

Corrosion Mechanism of E-glass of Chemical Resistance Glass Fiber in Acid Environment

The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber were analyzed.The corrosion mechanism of ECR glass fiber in acid environment was also discussed.The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order: HNO_3H_2SO_4HCl.The acid effects on corrosion of ECR glass fiberis were totally different.Hydrochloric acid mainly destroyed the network structure of [AlO_4],while sulfuric acid and nitric acid mainly destroyed the structure of [SiO_4].The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si(OH)_4 during ion exchange.It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.     

US/H2O2组合工艺催化降解苯酚水溶液的研究

研究了苯酚水溶液在超声波/过氧化氢(US/H2O2)复合氧化工艺条件下的降解效果及机理.详细讨论了H2O2体积质量、苯酚初始体积质量、溶液初始pH和外加Fe2+等因素对US/H2O2工艺氧化降解苯酚的影响.结果表明:在单独的超声波辐照或者过氧化氢氧化下苯酚去除率很小,而在组合氧化过程US/H2O2工艺中有显著的提高;苯酚降解的拟一级动力学速率常数增强因子可达到6.904,存在明显的协同效应     

Bio-decomposition of rock phosphate containing pyrites by Acidithiobacillus ferrooxidans

Leaching soluble phosphorus from rock phosphate containing pyrites by Acidithiobacillusferrooxidans （A. f.） is feasible, and the reaction mechanism is as follows. Pyrites are oxidized by A. f. to produce H2SO4 and FeSO4; the rock phosphate is decomposed by H2SO4, forming soluble phosphorus compounds; and Fe^2＋ from FeSO4 is oxidized to Fe%3＋, providing energy for the growth ofA. f.. In this process, as H2SO4 is produced in the reaction, an acidic condition in the culture medium is formed, which benefits the growth ofA. f. and aids both continuous oxidation of pyrites and leaching of soluble phosphorus from rock phosphate. The fraction of phosphorous leached can reach the largest in the presence of 1.0 g/L Fe^3＋, 200 mg/L Mg^2＋ and 400 mg/L NH^4＋. The optimal technological parameters on the fraction of phosphorous leached are as follows： the volume fraction of inocula ofA. f., the mass ratio of pyrites to rock phosphate and the pH value are in ranges of 5%-25%, 3：1- 5：1 and 1.8- 2.2, respectively.     

Numerical simulation of chemical vapor deposition reaction in polysilicon reduction furnace

Three-dimensional model of chemical vapor deposition reaction in polysilicon reduction furnace was established by considering mass, momentum and energy transfer simultaneously. Then, CFD software was used to simulate the flow, heat transfer and chemical reaction process in reduction furnace and to analyze the change law of deposition characteristic along with the H_2 mole fraction, silicon rod height and silicon rod diameter. The results show that with the increase of H_2 mole fraction, silicon growth rate increases firstly and then decreases. On the contrary, SiHCl_3 conversion rate and unit energy consumption decrease firstly and then increase. Silicon production rate increases constantly. The optimal H_2 mole fraction is 0.8-0.85. With the growth of silicon rod height, Si HCl3 conversion rate, silicon production rate and silicon growth rate increase, while unit energy consumption decreases. In terms of chemical reaction, the higher the silicon rod is, the better the performance is. In the view of the top-heavy situation, the actual silicon rod height is limited to be below 3 m. With the increase of silicon rod diameter, silicon growth rate decreases firstly and then increases. Besides, SiHCl_3 conversion rate and silicon production rate increase, while unit energy consumption first decreases sharply, then becomes steady. In practice, the bigger silicon rod diameter is more suitable. The optimal silicon rod diameter must be over 120 mm.