两步酸化DPASV对乐安江沉积物水提液中铜的毒性形态分析

本文采用两步酸化分脉冲阳极溶出伏安法（ＤＡＭ－ＤＰＡＳＶ）对乐安江沉积物水提液中的铜进行形态分析，并与直接ＤＰＡＳＶ测试及生物测试（Ｄ，ｍａｇｎａ）结果进行了比较，结果表明，直接ＤＰＡＳＶ测试因水体中络合剂和表面活性剂的干扰而低估了毒性形态，而两步酸化ＤＰＡＳＶ较好地反映出了铜的毒性形态。     

基于MnOx-CeO2/PPSN的低温SCR脱硝

采用超声法,将经400℃煅烧、锰摩尔分数为40%的MnO_x-CeO₂负载到经硝酸处理后的聚苯硫醚(PPSN)滤料上,制备了MnO_x-CeO₂/PPSN滤料。以氨气为还原剂,测试了MnO_x-CeO₂/PPSN滤料低温SCR过程中的催化活性,同时研究了催化温度、NH₃体积分数、O₂体积分数、催化剂负载量等因素对其NO脱除效率的影响。研究发现,当MnO_x-CeO₂负载量为296g/m²时,在催化温度130~160℃、NH₃/NO略大于1、O₂体积分数约5%时,MnO_x-CeO₂/PPSN滤料具有较高的NO脱除效率。在催化温度、NH₃体积分数、O₂体积分数一定时,MnO_x-CeO₂/PPSN滤料的NO脱除效率随负载量的增大而增大。     

基于广义信息域离散轨迹变换的随机数生成器

广义信息域是所有可表示为二进制编码的数字信息构成的空间. 本文提出一种基于广义信息域离散轨迹变换的随机数生成器. 该生成器将广义信息域作为熵源空间, 把用户选择的数字信息作为熵源输出, 在对熵源输出进行重构处理的基础上使用离散轨迹变换方法生成随机数. 本文提出的生成器在平衡度、周期和抗碰撞等性能上均表现优良, 并通过美国国家标准技术研究院 测试证明其具有理想的随机性, 可以供用户快速方便地生成高安全随机数.     

从输出断言逆向思考的程序设计

本文对[1]中提出的开发循环程序的模型作了进一步扩充。提出了建立<修改程序变量的表达式>的原则。通过实例说明了这些原则对设计较复杂的程序的重要意义。     

基于格子Boltzmann方法的纤维增强气凝胶复合材料等效热导率求解

对于纤维增强SiO2气凝胶复合隔热材料的等效热导率,以往主要通过提出简化结构之后利用等效电路方法进行理论求解。本文提出一种纤维结构的计算机随机生成方法,生成了不同的纤维气凝胶复合材料等效结构单元;采用三维格子Boltzmann模型求解该等效结构的温度场,并计算了复合材料常温下的等效热导率。本文数值预测结果与理论计算结果及相关实验结果吻合良好,表明本文模型能够有效地预测纤维-气凝胶复合材料的等效热导率。     

Mechanical properties an undercut evaluated resonance test and of silicon nanobeams with by combining the dynamic finite element analysis

Mechanical properties of silicon nanobeams are of prime importance in nanoelectromechanical system applications. A numerical experimental method of determining resonant frequencies and Young＇s modulus of nanobeams by combining finite element analysis and frequency response tests based on an electrostatic excitation and visual detection by using a laser Doppler vibrometer is presented in this paper. Silicon nanobeam test structures are fabricated from silicon-oninsulator wafers by using a standard lithography and anisotropic wet etching release process, which inevitably generates the undercut of the nanobeam clamping. In conjunction with three-dimensional finite element numerical simulations incorporating the geometric undercut, dynamic resonance tests reveal that the undercut significantly reduces resonant frequencies of nanobeams due to the fact that it effectively increases the nanobeam length by a correct value △L, which is a key parameter that is correlated with deviations in the resonant frequencies predicted from the ideal Euler-Bernoulli beam theory and experimentally measured data. By using a least-square fit expression including △L, we finally extract Young＇s modulus from the measured resonance frequency versus effective length dependency and find that Young＇s modulus of a silicon nanobeam with 200-nm thickness is close to that of bulk silicon. This result supports that the finite size effect due to the surface effect does not play a role in the mechanical elastic behaviour of silicon nanobeams with thickness larger than 200 nm.     

Mechanical properties of silicon nanobeams with an undercut evaluated by combining the dynamic resonance test and finite element analysis

Mechanical properties of silicon nanobeams are of prime importance in nanoelectromechanical system applications.A numerical experimental method of determining resonant frequencies and Young’s modulus of nanobeams by combining finite element analysis and frequency response tests based on an electrostatic excitation and visual detection by using a laser Doppler vibrometer is presented in this paper.Silicon nanobeam test structures are fabricated from silicon-oninsulator wafers by using a standard lithography and anisotropic wet etching release process,which inevitably generates the undercut of the nanobeam clamping.In conjunction with three-dimensional finite element numerical simulations incorporating the geometric undercut,dynamic resonance tests reveal that the undercut significantly reduces resonant frequencies of nanobeams due to the fact that it effectively increases the nanobeam length by a correct value △L,which is a key parameter that is correlated with deviations in the resonant frequencies predicted from the ideal Euler-Bernoulli beam theory and experimentally measured data.By using a least-square fit expression including △L,we finally extract Young’s modulus from the measured resonance frequency versus effective length dependency and find that Young’s modulus of a silicon nanobeam with 200-nm thickness is close to that of bulk silicon.This result supports that the finite size effect due to the surface effect does not play a role in the mechanical elastic behaviour of silicon nanobeams with thickness larger than 200 nm.     

采用深度刻蚀与XPS能谱研究缓蚀膜/镀铜层/铁基体界面成分

为了探索焦磷酸盐镀铜层与铁基体结合强度差的原因,采用波谱技术,分析了纵向界面各种元素的成分变化,讨论了金属基体表面粗糙度对元素分布的影响.根据刻蚀时间可将膜层分为三部分:N,O量迅速减少的表面层,有基本固定组成的中间层和占一半厚度的出现基体元素的混合干扰层.通过对后期混合层中氧含量的分析,可得出镀铜层/铁基体界面含氧层的存在是影响电镀层与基体结合强度的主要原因的结论.     

一类无限维非光滑发展系统的时间最优控制

本文讨论了一类Banach空间上的非光滑半线性发展系统的时间最优控制问题,在适当的条件下证明了相应的Pontryagin型最大值原理.     

一类无限维非光滑发展系统的时间最优控制

本文讨论了一类Banach空间上的非光滑半线性发展系统的时间最优控制问题,在适当的条件下证明了相应的Pontryagin型最大值原理.