基于驻留时间补偿的抛光误差控制方法

 针对计算机控制光学表面成形中光学表面存在中高频误差的问题,提出了一种基于驻留时间补偿的有效控制方法。分析了抛光误差的形成机理和影响因素,对系统的误差影响因素进行分类和定量描述,构建了抛光过程中磨损影响因子、浓度变化影响因子和系统影响因子。基于各影响因素的影响因子对抛光驻留时间的求解函数进行了修正,提出采用离散最小二乘法对修正的函数求解驻留时间。研究表明：这种补偿方法能提高计算机控制光学表面成形技术中加工模型的精度,减小光学表面的残余误差。     

Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO₂) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers.For the flavour removal test, two types of multilayer films were prepared, DLC/TiO₂ films and DLC/TiO₂/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO₂-coated and the DLC/TiO₂/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO₂ coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO₂/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO₂/DLC film had a photocatalytic effect even though the TiO₂ film was covered with the DLC film.     

过渡金属卤化物改性非碳基吸附剂脱汞研究

以6种大比表面积非碳基成分为载体,经过渡金属卤化物改性处理后制成汞吸附剂,并对其不同烟气气氛和温度下的汞吸附性能及汞氧化率进行了研究。CuCl_2改性氧化铝在各种烟气条件下均表现出较好的汞吸附性能。FeCl_3改性沸石的汞脱除率相对略低,但它制作成本较低。这两种非碳基吸附剂在未来有较好的应用前景。改性吸附剂的最适宜反应温度100～200℃。     

不同金属在催化脱硝过程中作用研究

采用共浸渍法和分步浸渍法在氧化铝载体上通过调节金属元素的负载量和负载顺序制备了多种催化剂,测试了其在NH3作为还原剂条件下的低温催化脱硝活性,研究各种活性组分在脱硝过程中的作用,考察浸渍顺序对脱硝性能的影响。在(?)(NO)=500×10~(-6),n(NH_3):n(NO)=1:1和(?)(O_2)=3.6%的条件下进行试验,结果表明,Mn在脱硝反应中是主要的活性组分,而Fe和Zr是助催化组分;浸渍顺序对催化剂脱硝活性有一定影响;当Fe负载量达到10%时,制备的催化剂5Zr-5Mn-10Fe/Al_2O_3脱硝活性最佳。     

依赖型值的非奇异自适应三角剖分方法

1 引言 众所周知,三角剖分是在许多科学计算如曲面设计与拟合、有限元计算以及其他大型科学计算等领域中不可回避的问题.     

Removing Spikes from Voltammetric Curves in the Presence of Random Noise

The presence of noises and spikes in the experimental curve generates problems in the process of visualization and interpretation of the data. The procedure for spikes removal from voltammetric curves which are additionally distorted by random noise of different amplitude is proposed. The developed method bases on the assumption that spikes are measuring points corrupted by the gross errors. The statistical tests for detecting such errors are applied. Recognized spikes are replaced by points obtained by polynomial interpolation. The method eliminates close to 100% of spikes and reconstructs the ideal curve shape better than other algorithms. The considered new procedure gives the improvement of analytical parameters and may be applied for the set of curves in voltammetric experiment. Because the method is statistically valid it may be used for automatic spikes removal in intelligent computerized measuring systems in analytical chemistry.     

Selective removal of chlorine from chloroaromatic pollutants by electrocatalytic reduction over palladium-loaded carbon felt

This brief review outlines work on effective hydrodechlorination of environmentally persistent chlorine-containing aromatic pollutants by electrocatalytic reduction at Pd-loaded carbon felt. The selective removal of chlorine from phenoxy herbicides 2,4-D and 2,4,5-T, chlorinated biphenyls and naphthalene was readily achieved (i) at room temperature and (ii) directly in aqueous media. No highly active reducing chemicals were required for such a treatment. The use of carbon felt of high surface area as a solution-permeable cathode offered high adsorption capacity for chloroaromatics, while supported palladium provided the system with a highly reactive reducing species supposed to be a surface-bound hydride, which was generated upon electrochemical reductive decomposition of water. A facilitating effect of bulky tetraalkylammonium cations of a supporting electrolyte on substrate conversion and product recovery is considered. The reaction mechanism for selective hydrodechlorination of chloroaromatics in aqueous media and scheme for activation of Pd-loaded carbon felt by electrolytic pre-treatment are proposed and discussed.     

Ultraviolet laser removal of small metallic particles from silicon wafers

Laser removal of small 1 μm sized copper, gold and tungsten particles from silicon wafer surfaces was carried out using ultraviolet radiation at 266 nm generated by Nd:YAG harmonic generation. Successful removal of both copper and gold particles from the surface was achieved whereas tungsten particles proved to be difficult to remove. The cleaning efficiency was increased with an increase of laser fluence. The optimum processing window for safe cleaning of the surface without any substrate damage was determined by measuring the damage threshold laser fluence on the silicon substrate and the required fluence for complete removal of the particles. The different cleaning efficiencies with particle type are discussed by considering the adhesion force of the particle on the surface and the laser-induced cleaning force for the three different particles.     

光催化法脱出水中无机氮的研究进展

综述了近年光催法脱除水中无机氮(氨氮、亚硝酸氮和硝酸氮)的研究进展和现状.重点介绍了氨氮的光催化氧化、硝酸氮和亚硝酸氮光催化还原的机理及其影响因素,并据此提出了本领域今后的研究方向.