光致固液转变的有机小分子、高分子和其他材料研究进展

通过传统的热法-加热可以实现很多材料的固液转变,固液转变是材料的宝贵性质,液化后的材料可以通过模具制备各种形状的物品。与热致固液转变相比,光致固液转变具有更高的时空分辨率,可以利用非接触的方式精确地照射在需要液化的部位,这使得光致固液转变材料在功能材料领域有重要的应用前景。本文介绍了光致固液转变的有机小分子、高分子和其他材料研究进展,讨论了其转变机理和设计原则,并介绍了光致固液转变材料在可重复利用的粘合剂、光刻胶、光致驱动器和自愈合材料等方面的潜在应用前景。     

固体氧化物电解池

固体氧化物电解池（SOEC）是一种先进的电化学能量转化装置,可利用清洁一次能源产生的电能和热能,以H₂O和/或CO₂为原料,高效电解制备氢气或碳氢燃料,有望实现大规模能量高效转化和存储。该技术具有高效、简单、灵活、环境友好等特点,是目前国际能源领域的研究热点。本文就固体氧化电解池技术原理、关键材料、电堆技术、衰减控制和经济竞争力等方面进行分析和介绍,并对其应用前景进行展望。     

Single-photon modulation spectrum

We present a robust method of single-photon modulation by directly modulating the single photons and observe its frequency spectrum. Compared with conventional photon counting technique, the single-photon modulation spectrum shows that the method could not only realize high-frequency modulation but also obtain higher signal-to-noise ratio. Moreover, the theoretical calculations show good agreement with the experimental results.     

拉伸载荷下混凝土体分形内聚模型

在综合考虑混凝土试件微断裂面分形分布及断面分形演化基础上,提出了体分形内聚模型,用于描述混凝土试件在准静态拉伸载荷作用下的破坏行为。数值计算结果与现有实验数据吻合较好。此外,采用该模型分析了混凝土骨料级配对材料软化性质的影响。结果表明,在拉伸载荷作用下,混凝土骨料级配越均匀,材料的软化特征越明显。     

高效液相色谱-等离子质谱联用分析食品中的主要有机砷和无机砷

应用液相色谱-等离子质谱联用的方法分析食品样品中的主要有机砷(一甲基砷和二甲基砷)和无机砷(三价砷和五价砷)。 采用50%(体积分数)甲醇水溶液作为萃取剂,将食品样品进行预处理,再以5 mmol/L四丁氢铵,2 mmol/L丙二酸和5%(体积分数)甲醇水溶液作为流动相(pH 5.9),C18色谱柱(150 mm×4 mm i.d., 5 μm)将样品萃取液进行液相色谱分离,最后进入等离子质谱仪定性分析。 经测定发现,新鲜蔬菜和水果样品中主要含有的无机砷为三价砷和五价砷,有机砷为二甲基砷。一甲基砷在个别样品     

旋转锥面$l_\infty$拟合的截断光滑化牛顿法

In this paper, the rotated cone fitting problem is considered. In case the measured data are generally accurate and it is needed to fit the surface within expected error bound, it is more appropriate to use l∞ norm than 12 norm. l∞ fitting rotated cones need to minimize, under some bound constraints, the maximum function of some nonsmooth functions involving both absolute value and square root functions. Although this is a low dimensional problem, in some practical application, it is needed to fitting large amount of cones repeatedly, moreover, when large amount of measured data are to be fitted to one rotated cone, the number of components in the maximum function is large. So it is necessary to develop efficient solution methods. To solve such optimization problems efficiently, a truncated smoothing Newton method is presented. At first, combining aggregate smoothing technique to the maximum function as well as the absolute value function and a smoothing function to the square root function, a monotonic and uniform smooth approximation to the objective function is constructed. Using the smooth approximation, a smoothing Newton method can be used to solve the problem. Then, to reduce the computation cost, a truncated aggregate smoothing technique is applied to give the truncated smoothing Newton method, such that only a small subset of component functions are aggregated in each iteration point and hence the computation cost is considerably reduced.     

表面织构与离子液体润滑组合体系的摩擦学性能研究

利用激光加工技术在钛合金表面构建不同尺寸的圆形微坑织构图案. 利用MS-T3001型试验机测试了圆形微坑织构、离子液体[1-丁基-3-甲基咪唑三氟甲基磺酰胺盐和十四烷基三丁基季鏻双(2-乙基己基)磷酸盐]及二者构成润滑组合的摩擦磨损性能. 利用金相显微镜观察圆形微坑织构的尺寸和表面形貌,利用扫描电镜分析摩擦过程前后织构化表面的形貌,采用ANSYS Fluent软件模拟分析表面织构参数和离子液体理化性质对摩擦学性能的影响. 结果表明,表面织构、离子液体、表面织构与离子液体的复合体系均展示了良好的减摩抗磨性能. 优化表面织构与离子液体的组合能够提升润滑体系的摩擦学性能. 表面织构与离子液体组成的复合润滑体系,摩擦系数随圆形微坑织构直径的增大而减小,归因于圆形微坑织构能够储存磨屑和离子液体并形成稳定的离子液体润滑薄膜,黏度较大的离子液体在收敛区间产生楔形效应,导致对上摩擦副升力增大.      

求解全局优化问题的三角进化算法

This paper presents a hybrid heuristic-triangle evolution （TE） for global optimization. It is a real coded evolutionary algorithm. As in differential evolution （DE）, TE targets each individual in current population and attempts to replace it by a new better individual. However, the way of generating new individuals is different. TE generates new individuals in a Nelder- Mead way, while the simplices used in TE is 1 or 2 dimensional. The proposed algorithm is very easy to use and efficient for global optimization problems with continuous variables. Moreover, it requires only one （explicit） control parameter. Numerical results show that the new algorithm is comparable with DE for low dimensional problems but it outperforms DE for high dimensional problems.     

阴极支撑Ni-YSZ/YSZ/LSM-YSZ固体氧化物电解池制氢性能研究

利用固体氧化物电解池(Solid oxide electrolysis cell,SOEC)在高温下电解水蒸气制氢,被认为是未来的大规模制氢方法之一.本文采用干压法和丝网印刷法制备了SOEC,考察了氢电极气氛和工作温度对SOEC电解性能的影响,测试了SOEC的稳定性.实验结果表明:氢电极进气中适宜的水蒸气含量为70%～80%;电解池在800,850和900℃,1.50 V的产氢速率分别为89,163和243 N·ml·cm-2·h-1;在900℃以0.33 A·cm-2恒流电解2 h,电解电压的稳定值为0.98 V,并且电解池运行稳定,无明显衰减.阻抗谱解析表明,电极过程是整个电解池电极反应的速度控制步骤.     

还原氧化石墨烯表面聚苯胺纳米阵列的制备及电化学电容性能

本文以阳极氧化铝(AAO)膜为模板,通过恒电位法在自组装还原氧化石墨烯(rGO)膜表面制备有序聚苯胺(PANI)纳米线阵列。通过拉曼光谱和场发射扫描电子显微镜分别对其结构和微观形貌进行了表征,并对PANI纳米线阵列的电化学电容性能进行了测试。结果表明,rGO膜表面可电沉积PANI,电沉积得到的PANI纳米线阵列具有比PANI薄膜材料更高的电容和比电容。