HZSM-5催化下N2O5对氯苯的选择性硝化研究

工业传统混酸硝化法严重腐蚀设备和污染环境,同时对硝基氯苯选择性较低,针对这个问题,研究了在HZSM-5分子筛催化下,五氧化二氮对氯苯的硝化反应。由于HZSM-5优异的择形性,对硝基氯苯在硝化产物中的比例从原先的42%提高到81%。实验考察了反应温度、反应时间、催化剂用量及Si/Al等因素对反应结果的影响。研究表明,在温度为50℃,时间为1h,5gSi/Al质量比为260的催化剂HZSM-5作用下,反应条件最佳,此时氯苯硝化反应得率达到50%,对位选择性为85%。     

滩涂养殖在鱼塘混养模式下氮磷收支的研究

用15个上口面积为40m2,底部面积为20m2,深为1m的池塘,在相同的放养水平和投饲水平下,进行氮磷试验研究。本试验共设置五个处理:N/P=1,N/P=5,N/P=10,N/P=20,CK,每个处理设置3个重复。试验结果表明:试验中投放的饵料、肥料分别占氮总输入的30%~46.12%和37.81%~39.52%;占磷总输入的15.44%~74.74%和16.31%~79.12%。在支出项目中,鱼类的收获支出的氮磷占氮磷总输入的52.31%~75.95%和8.98%~40.39%;沉积在底泥中的氮磷分别占氮磷总输入的19.95%~36.3%和35.82%~86.52%;底泥中氮磷的渗漏占其总输入的1.49%~12.66%和1.09%~11.28%,其中氮的损失率对照最低为1.49%,N/P=20的损失最高为12.66%;磷的损失率N/P=10的处理最低为1.09%,对照为最高11.28%。     

胶体五氧化二锑研究现状及发展方向

对胶体五乳化二锑的研究现状进行了回顾，详细概述了胶体五乳化二锑的各种制备方法及其特点和适用范围，讨论了两种成胶理论。针对目前存在的问题，对胶体五乳化二锑的研究方向及研究重点提出了几点建议。     

Measurement of Tritiated Moisture in Gas Stream by Collection Method Using P2O5 Desiccant

A measurement method of tritiated moisture in gas stream has been developed by taking advantage of the high hygroscopic and deliquescent performances of phosphorus pentoxide P₂O₅. The method includes two techniques; one is of collecting moisture from gas stream using the desiccant, the other is of preparing homogeneous liquid scintillation cocktails containing the phosphide and the collected moisture. By introducing an idea of common use of standard vials as the collector cells disposable and the scintillation cocktail containers, the treatment process has been simplified and the chances of error arising in process for subsequent tritium analysis have been decreased. From results of a typical experiment, a relationship between the collection efficiencies and the moisture contents of P₂O₅ has been obtained and the isotope effect on the moisture collection has been elucidated. The collecting performance and the isotope effect are discussed here considering the mass transport phenomena in collector cell.     

五氧化二钽薄膜的制备及其I-U特性

本文利用脉冲直流反应磁控溅射的方法制备了五氧化二钽 (Ta2 O5)薄膜 ,俄歇电子能谱仪测试了薄膜的成分含量 ,椭偏仪测试了Ta2 O5薄膜的厚度和折射率 ,XRD分析了薄膜的晶体结构 ,并且分别研究了氧气含量、基底温度等成膜工艺对薄膜的影响。研究结果表明薄膜的成分主要是由氧气含量决定的。利用金属 绝缘体 (介质膜 ) 金属 (MIM)结构初步对Ta2 O5薄膜进行了电学性能的测试 :皮安电流电压源测试了薄膜的I U特性 ,制备出的薄膜折射率在 2 1～ 2 2 ,MIM的I U特性曲线显示了较好的对称性和低的漏电流密度     

红土镍矿电炉熔炼提取镍铁合金的研究

采用电炉直接还原熔炼工艺从红土镍矿中提取镍铁合金,研究了还原剂(焦粉)和熔剂(石灰石)配比对合金中镍品位、金属回收率及硫、磷在渣和合金中分配比(LS,LP)的影响及行为。综合考虑镍铁合金中镍的品位和金属回收率,试验确定了最佳熔炼条件:焦粉配比11%,熔剂配比11%。在最佳条件下,合金中镍品位为22.8%,镍回收率达97.6%,LS,LP分别为0.024和0.145。     

Inexpensive synthesis of 1,4-bis(4-aminophenoxy)-2- (6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene and its oxygen-plasma resistant polyamides

Inexpensive synthesis of diamine, 1,4-bis(4-nitrophenoxy)-2-(6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene was revealed in this work. Based on the diamine, a series of organosoluble polyamides were prepared by direct polycondensation of the diamine with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. The number-average molecular weights of the resulting polyamides range from 4.2 × 10⁴ to 10.5 × 10⁴ g/mol, and the weight-average molecular weights are in the range of 7.5-28.2 × 10⁴ g/mol. The T_gs of these polyamides range from 210 to 255 °C by dynamic mechanical analysis. The resulting polyamides are tough and flexible with tensile strength, elongation at break and moduli range from 84 to 101 MPa, 4.8-7.0%, and 2.36-3.22 GPa, respectively. The degradation temperatures (T_d 5%) and char yields at 800 °C in nitrogen range from 460 to 486 °C and 59-68 wt%, respectively. The cutoff wavelength of these polyamides falls in the range of 345-366 nm, showing a very light color characteristic. In addition, these polyamides display good oxygen plasma resistance.     

Molecular absorption spectrophotometric method for the determination of phosphorus in biodiesel

A molecular absorption method is proposed for the determination of phosphorus in biodiesel. The samples are mineralized using an ashing procedure at 550 °C followed by dissolution of the residue. The analytical procedure is based on the formation of a blue molybdenum complex. 1-amino-2-naphthol-4-sulfonic acid is used as reducing agent. The method was applied to biodiesel samples prepared from soy, canola and sunflower oils and from bovine fat. The limit of detection is 0.57 mg P kg⁻¹ and the limit of quantification is 1.7 mg P kg⁻¹. The observed mean relative standard deviation is about 5%. The simplicity of the procedure added to its precision, accuracy and low cost suggest that it is an excellent option for the determination of phosphorus in biodiesel.     

Comparison of Oxygen Transfer Parameters Determined from the Steady State Oxygen Uptake Rate and the Non-Steady-State Changing Power Level Methods

In this study, a laboratory scale Univ. of Cape Town enhanced biological phosphorus removal process was operated under controlled conditions at a solids retention time of 15 days. Results are presented for the process performance and oxygen transfer parameters determined by applying the steady state oxygen uptake rate (OUR) and the changing power level (CPL) techniques, as per ASCE standard guidelines. The testing periods were temporally separated to eliminate interference of the tests. During the application of the CPL method, the sludge volume index gradually increased and higher values of the oxygen transfer rate and alpha were measured, in comparison to the data from the steady state OUR method, under similar process performance. Furthermore, the mass transfer rate decreased as the CPL method of testing continued. In contrast, the oxygen transfer parameters remained uniform during the time when the OUR method was applied. The data indicated that the CPL method resulted in higher and variable oxygen transfer parameters, even though the process performance remained unchanged. Therefore, a more rigorous evaluation of the CPL method is recommended to clarify the validity of the test.     

用高纯V_2O_5制备钒电池电解液的工艺研究

以高纯V2O5为原料,用SO2还原法制备VOSO4、锌-氨法制备V2(SO4)3,分别作为钒电池正、负极电解液的活性物质。对电解液的制备工艺进行了研究,同时对SO2还原V2O5的反应机理进行了研究,计算了制备VOSO4的反应焓变和吉布斯自由能变化,并对制备的电解液进行了电化学性能测试。结果表明:该法生产工艺简单,生产效率高,电解液浓度可任意调配;在电流密度为5.0 m A/cm2时,电池的电流效率、电压效率、能量效率分别为94.5%、91.2%和90.1%,满足钒电池电解液的性能要求。