PCC载体氧化剂的制备及应用研究

制备得到各种有代表性的氯铬酸吡啶(PCC)无机载体氧化试剂,以苯甲醇选择性氧化成苯甲醛为探针反应,考察了载体、反应条件对氧化反应效率的影响,控制各载体氧化剂中PCC的负载量均为1.8 mmol/g。室温下反应,搅拌时间为30 m in,苯甲醇的氧化反应产率为:分子筛65.8%,活性炭75.4%,氧化铝94.6%,硅胶96.9%,相同条件下PCC的产率为65.8%。硅胶是制备负载PCC的优良载体,在载体氧化剂对苯甲醇的氧化反应中,一定范围内增加反应时间和载体加入量都可以提高氧化产率。     

铜浸出液的净化除铁研究

研究了氧化－中和沉淀法从铜浸出液中除铁的工艺条件，并介绍了工业实践。     

Comparative effects of cobalt carboxylates on the thermo‐oxidative degradation of LDPE films

This article reports the effect of three cobalt carboxylates—cobalt stearate (CoSt₃), cobalt palmitate (CoPal₃), and cobalt laurate (CoLau₃)—on the thermo‐oxidative degradation of low‐density polyethylene (LDPE) films prepared by sheeting process. The carboxylates were blended with LDPE in the concentration range of 0.05–0.2% (w/w). The degradation was monitored by techniques such as FTIR spectroscopy, change in the mechanical properties (tensile strength and elongation at break), viscometry, surface electron microscopy, melt flow index measurements, and apparent density measurements. Studies indicate that films containing these additives are highly susceptible to thermo‐oxidative degradation. Oxygen containing functionalities such as carbonyl and vinyl species are generated on the surface of polyethylene because of thermo‐oxidation, as indicated by FTIR studies. This oxidative process is accelerated in the presence of cobalt carboxylates. The degradation of LDPE was found to increase proportionally with concentration as well as with increasing chain length of the cobalt carboxylate, and follow the order CoSt₃ > CoPal₃ > CoLau₃. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3758–3765, 2007     

The Internal Oxidation of Ternary Alloys II: The Coupled Internal Oxidation of the Two Most-Reactive Components Under Intermediate Oxidant Pressures

The kinetics of the coupled internal oxidation of the two most-reactive components in the scaling of ternary alloys under oxidant pressures below the stability of the oxide of the most noble component are examined using a number of simplifying conditions which allow to develop an approximate analytical treatment. The precipitation of the two oxides may occur either at a single front or at two different fronts of internal oxidation. The former case corresponds to a unique solution for all the parameters involved in the process. On the contrary, the existence of two fronts of internal oxidation yields a finite range of possible solutions for the oxidation kinetics as well as for all the other relevant parameters. Even though the present treatment does not allow to predict which solution will be adopted by a real system, it is possible to set limits to the values of the parameters yielding physically-acceptable solutions. After considering a general case, the treatment is applied to a real system already examined experimentally.     

The Internal Oxidation of Ternary Alloys I: The Single Oxidation of the Most-Reactive Component Under Low Oxidant Pressures

The internal oxidation of the most-reactive component C of ternary A–B–C alloys by a single oxidant is examined assuming a gas-phase oxidant pressure below the stability of the oxides of the other two components. The precipitation of the most-stable oxide leaves behind a matrix composed of a binary alloy of the two less-reactive components, whose composition affects the solubility and diffusivity of the oxidant within the region of internal oxidation, with an effect on the reaction kinetics. Approximate relations between these properties are proposed and used to predict the kinetics of internal oxidation of C under the assumption of parabolic rate law. The results obtained for the ternary alloys are compared with the behavior of binary A–C and B–C alloys with the same C content. A new important factor in establishing the difference between the internal oxidation in ternary A–B–C alloys and in binary A–C and B–C alloys under a fixed gas-phase oxygen pressure and C content is the ratio between the concentrations of A and B in the bulk ternary alloy.     

The Internal Oxidation of Ternary Alloys. VI: The Transition from Internal to External Oxidation of the Most-Reactive Component under Intermediate Oxidant Pressures

The conditions for the transition from internal to external oxidation of the most-reactive component C of ternary A–B–C alloys are examined, assuming the presence of external scales of the oxide of the component of intermediate reactivity B. For this, approximate expressions for the diffusion coefficient of oxygen and for the concentration of oxygen dissolved in the binary A–B alloy matrix within the zone of internal oxidation as functions of the composition of the metal matrix within the zone of internal oxidation are used. Numerical calculations of the critical content of C needed for this transition are carried out for different combinations of values of the various parameters involved. The results obtained for the ternary alloys are compared with the corresponding data calculated for the binary A–C and B–C alloys under oxygen pressures insufficient to oxidize the most-noble alloy component. This allows to predict the possibility of existence of a third-element effect under intermediate oxidant pressures.     

锑化铟抛光片表面粗糙度优化研究

锑化铟是中波红外探测应用较广的材料。抛光片的表面粗糙度是影响器件性能的关键指标。研究了锑化铟化学机械抛光(Chemical Mechanical Polishing, CMP)液的pH值、氧化剂比例以及抛光液流速对锑化铟抛光片表面粗糙度的影响,并结合原子力显微镜(Atomic Force Microscope, AFM)和表面轮廓仪测试对抛光片的表面粗糙度进行了表征和优化。结果表明,当pH值为8、氧化剂比例为0.75%、抛光液流速为200 L/min时,InSb晶片的表面粗糙度为1.05 nm (AFM),同时晶片的抛光宏观质量较好。     

过硼酸钠在有机合成中的应用

过硼酸钠（ＳＰＢ）是一种安全、稳定、方便、价廉的理想氧化剂，本文综述了它对各类有机化合物的氧化反应。     

天然栀子黄色素稳定性研究

以吸光度值变化为基础初步探讨氧化剂和抗氧化剂对栀子黄色素溶液稳定性的影响.结果表明,当氧化剂碘酸钾、溴酸钾与栀子黄色素溶液共存时,会引起栀子黄色素的氧化褪色.添加抗氧化剂抗坏血酸、异抗坏血酸钠,能够明显延缓色素的褪色.为在食品体系中更有效地使用天然栀子黄色素提供了依据.     

某铀矿搅拌浸出氧化剂替代试验研究

为解决某铀矿石酸法搅拌浸出成本居高不下的问题,探索用氯酸钠替代软锰矿作为氧化剂处理该矿石的可行性。小型、验证试验及工业应用实践表明:在适当的条件下,浸出率可达93%以上,与现有生产中以软锰矿作氧化剂的浸出率相当;此外,氯酸钠替代软锰矿并未对其他工序产生影响,且浸出成本节约了30%以上。因此,用氯酸钠作氧化剂进行常规酸法搅拌浸出处理该矿石工艺可行。