气调库及气调库设备

分析果蔬贮藏保鲜期的生理变化，介绍气调保鲜库设计施工验收中的技术要求，保鲜工艺和主要设备。     

Kinetic of CO2 absorption and carbamate formation in aqueous solutions of diethanolamine

The absorption rates of CO₂ into aqueous solutions of Diethanolamine (DEA) with varying concentrations from 0.2 to 4M and temperature range from 293 to 323 K were measured by using a laboratory stirred reactor. The CO₂ partial pressure was varied in a range that the reaction would occur in pseudo first order regime. Experimental data were analyzed and the kinetic parameters associated with the reaction were determined. The activation energy for the deprotonation of the intermediate zwitterion was estimated at about 11.4 kcal/mol. The contribution of carbamate formation to the overall absorbed CO₂ was experimentally evaluated and found to be of the order of 100%.     

Electrocatalysis of chlorine evolution on different materials and its influence on the performance of an electrochemical reactor for indirect oxidation of pollutants

Two different Ti/Pt–Ir materials (commercial and home made) and Ti/PdO + Co₃O₄ were investigated for their electrocatalytic properties versus Cl₂ evolution reaction. The materials were used in a batch electrochemical reactor to treat biologically recalcitrant di-azo compound. An electrochemically driven oxidation, mediated by a Cl₂/Cl⁻ couple, proved efficient for destruction of this complex organic molecule, causing cleavage of the conjugated double bonds and destruction of unsatured bonds. Both Ti/Pt–Ir materials performed well; lower kinetics obtained with the Ti/PdO + Co₃O₄ anode was caused by adsorption of the model compound, evidenced in preliminary voltammetric measurements. The dye oxidation reaction followed the second order kinetics with partial orders in the model compound and (time varying) chlorine concentrations equal to one. Specific energy consumption of 3.12 kWh m⁻³ proved the process more economic than the homogeneous phase oxidation.     

Photochemical reduction of molecular weight and number of double bonds in natural rubber film

Natural rubber (NR) can be degraded depending on various factors such as heat, mechanical force, chemical reaction, and light. Light is a very interesting factor because it can cause the NR to degrade under low temperature and pressure. The photo-degradation of NR films was carried out to investigate the effects of the light and the temperature on the reduction of the weight-average molecular weight (Mw) and the double bonds in the NR films. The NR films, with and without catalysts, titanium dioxide (TiO₂), and potassium persulfate (K₂S₂O₈), were exposed to light from a mercury light bulb at 7,000 and 36,000 lux, and at the temperature of 25 °C and 80 °C for 192 hrs. After exposure, the Mw of the NR films was analyzed by gel permeation chromatography (GPC). Changes in the Mw were used to construct a kinetic model for the process, (1/Mw)=(1/Mw₀)+(kt/2M₀) where k is the rate constant, and M₀ is the Mw of the monomer unit. The linear relationship between 1/Mw and time suggested pseudo first-order processes with random scission. The Mw distribution information from the GPC was used to calculate the number of double bonds in the NR films. The trend of the double bonds reduction curves was quite similar to the result obtained from the calculation from the FTIR spectra. This indicated that this calculation method might possibly be another alternative way to obtain the number of double bonds in the NR.     

氯离子导体及其应用开发

本文围绕有希望实现实用化的PbCl_2基氯离子导体,着重从材料研制、应用探索及应用前景这三个方面概述了氯离子导体研究的状况和今后动向。     

二氧化碳对油井水泥石的腐蚀及其防护措施

在湿环境下,油气构造中富含的CO_2对水泥石产生碳化腐蚀,碳化结果使水泥石渗透率变大、抗压强度减小,诱发流体窜流、塑性地层井壁垮塌等事故,造成巨大的经济损失。介绍了在不同温度下的水泥水化产物及其碳化产物。从化学角度分析了CO_2在不同温度下对油井水泥环碳化腐蚀的机理、影响因素及防护措施。在低于110℃的温室下,CO_2的腐蚀速度受扩散控制,其影响因素包括水泥浆密度和水泥石渗透率及水泥石孔隙液中Ca(OH)_2的含量,在水泥中掺加活性硅灰或提高水泥浆密度可预防碳化腐蚀。在大于110℃的高温下,碳化腐蚀速度受水泥水化产物中Ca(OH)_2含量和水泥石碳化后渗透率大小的影响。正确的防腐工艺是在水泥石中加入10％—15％的石英砂,或者在纯水泥中加3％—8％的膨润土。     

Mathematical analysis and experimental results of applying enhanced-surface-area packed-bed electrodes in electrogenerative sulfur dioxide oxidation

The results of applying enhanced-surface-area packed-bed (ESAP) electrodes in electrogenerative SO₂/O₂ cells are reported to illustrate their utility and potential applications. Mathematical analysis with parameters pertinent to the experimental conditions shows that all electrocatalyst sites in these electrodes are expected to be uniformly utilized for electrochemical SO₂ oxidation. Experimental results showed that ESAP electrodes (1 mg Pt/cm²) could provide at least 5 times higher SO₂ conversion at given cell voltages than graphite sheet electrodes (1.5 mg Pt/cm²).     

以EMD作基础的氧化锰制成湿度敏感器的新技术

最近国外报道把ＥＭＤ粉末等制成湿度敏感器的技术，但对其作用机理的解释尚有欠妥之处，本文除简介此类湿度敏感器的工艺之外，还利用我们研究水蒸气对ＥＭＤｏＡ附的理论予以阐释，并确认其合理与否     

Uses of Ozone in a Three-Phase System for Water Treatment: Ozone Adsorption

A new technique of using ozone for water treatment is presented. This new technique consists of using a three-step-process composed firstly of ozone adsorption on an appropriate adsorbent, secondly water treatment, and thirdly regeneration of the adsorbent. Results regarding ozone adsorption (the first step) are presented in this paper. Different types of silica gel and a type of TiO₂ have been tested for ozone adsorption. It was found that the physical characteristics of the silica gel affect its capacity for ozone. Titanium dioxide has shown ozone decomposition instead of adsorption as it contains Lewis acid sites. An exponential decrease of the silica gel capacity with its moisture content has been found. Linear isotherms in the range of ozone concentrations less than 100?g/m³ NTP have been found. A particle diffusion model with linear equilibrium isotherm has been used to model the breakthrough curves in fixed bed columns.     

间接原子吸收分光光度法测定聚丙烯、聚乙烯中的微量(?)

介绍用原子吸收分光光度法测定PE、PP氯含量。该方法采用氧气燃烧法处理样品,用Ag~+沉淀Cl~-,经分离后用原子吸收光谱测溶液中剩余Ag~+浓度,从而得到样品中氯含量。讨论了仪器参数、操作条件对测定结果的影响,结果表明,在分离前存放4～30分钟对测试结果无影响。火焰法的测定条件为波长328.1nm、灯电流7.5mA、狭缝宽度0.4nm、C_2H_2压力0.025MPa、空气压0.16MPa、燃烧器高度7.5mm。实验采用的离心转速2000r/min、时间5分钟、HNO_3浓度1%。该法灵敏度可达0.1μg/ml、相对标准误差<2%。