酚醛树脂为原料制备双电层电容器用电极材料的工艺研究

以酚醛树脂为原料，NaOH为活化剂制取双电层电容器用高比表面积活性炭电极材料，考察了炭化温度、活化温度、活化剂用量、活化时间等工艺参数对活性炭比电容的影响。实验结果表明，在炭化温度为600℃，活化温度为900℃，碱炭比为4，活化时间为1h的工艺条件下，制得的高比表面积活性炭比电容可达58．8F／g，用它组装成的电容器具有良好的充放电性能和循环性能，既能在大电流下快速充放电也能在小电流下缓慢充放电，但存在微孔所占比例较高引起的分散电容效应，这是大电流下放电容量有所下降的主要原因。     

Longitudinal and temporal water temperature patterns in the Yangtze River and its influence on spawning of the Chinese sturgeon (Acipenser sinensis Gray 1835)

In this study, water temperature longitudinal and temporal patterns were investigated in four locations of the Yangtze River to identify their influence on spawning of the Chinese sturgeon (Acipenser sinensis Gray 1835). The results showed that, historically (1960–1980), the four locations, Pingshan (PS, 2,687 river kilometres [rkm]), Yichang (YC, 1,640 rkm), Chenglingji (CLJ, 1,265 rkm), and Hukou (HK, 805 rkm), all had similar average annual water temperatures (around 18.0 °C) but very different amplitudes: The upper two locations, PS (11.4–23.2 °C) and YC (9.1–25.9 °C), were relatively stable and had smaller amplitude than the lower two ones, CLJ (6.0–30.0 °C) and HK (5.9–30.8 °C). On the basis of the physiological effects for Chinese sturgeon, we defined three water temperature ranges: stressing (>23 °C), holding (23–20 °C), and spawning (20–16 °C). We found that the upper two locations with successful spawning of the Chinese sturgeon (PS and YC) had short or no stressing period but long holding and spawning periods. Currently (2013–2016), the impoundment of the Three Gorges Reservoir increases the time for water temperature decreasing to 20 °C at the current spawning ground (YC) in autumn, which increases the stressing and holding periods, and has significant negative impact on the spawning of Chinese sturgeon. Nonetheless, considering the very high stressing temperature and the short duration of the holding and spawning periods at CLJ and HK, we propose that YC is still the most suitable spawning location for the Chinese sturgeon.     

Continuous finite element schemes for a phase field model in two-layer fluid Bénard–Marangoni convection computations

In this article, we study a phase field model for a two-layer fluid where the temperature dependence of both the density (buoyancy forces) and the surface tension (Marangoni effects) is considered. The phase field model consisting of a modified Navier–Stokes equation, a Cahn–Hilliard phase field equation and an energy transport equation is derived through an energetic variational procedure. An appropriate variational form and a continuous finite element method are adopted to maintain the underlying energy law to its greatest extent. A few examples for Bénard–Marangoni convection in an Acetonitrile and n-Hexane two-layer fluid system heated from above will be computed to justify our phase field model and further show the good performance of our methods. In addition, an interesting experiment will be performed to show the competition between the Marangoni effects and the buoyancy forces.     

4-乙基-1-苯基环己醇的催化氢解

在乙醇体系中,4 丙基 1 苯基环己醇在2MPa氢气压力下200℃反应8h,完全氢解且反式选择性高,得到71.7%的反式产物和22.3%的顺式产物。考察了温度等对氢解反应的影响,发现高温有利于反式产物的生成。     

Measuring individual corrective reaction time using the intermittent illumination model

The corrective reaction time (t_cr) is an essential motor property when modelling hand control movements. Many studies designed experiments to estimate t_cr, but reported only group means with inconsistent definitions. This study proposes an alternative methodology using Drury's (1994) intermittent illumination model. A total of 24 participants performed circular tracking movements under five levels of visual information delay using a modified monitor in a darkened room. Measured movement speeds and the manipulated delays were used with the model to estimate t_cr of individuals and test effects of gender and path width. The results showed excellent model fits and demonstrated individual differences of t_cr, which was 273 ms on average and ranged from 87 to 441 ms. The wide range of t_cr values was due to significant effects of gender and path width. Male participants required shorter t_cr compared to female participants, especially for narrow path widths.     

Multiobjective evolutionary algorithm for manufacturing scheduling problems: state-of-the-art survey

Scheduling is an important tool for a manufacturing system, where it can have a major impact on the productivity of a production process. In order to find an optimal solution to scheduling problems it gives rise to complex combinatorial optimization problems. Unfortunately, most of them fall into the class of NP-hard combinatorial problems. In this paper, we focus on the design of multiobjective evolutionary algorithms (MOEAs) to solve a variety of scheduling problems. Firstly, we introduce fitness assignment mechanism and performance measures for solving multiple objective optimization problems, and introduce evolutionary representations and hybrid evolutionary operations especially for the scheduling problems. Then we apply these EAs to the different types of scheduling problems, included job shop scheduling problem (JSP), flexible JSP, Automatic Guided Vehicle (AGV) dispatching in flexible manufacturing system (FMS), and integrated process planning and scheduling (IPPS). Through a variety of numerical experiments, we demonstrate the effectiveness of these Hybrid EAs (HEAs) in the widely applications of manufacturing scheduling problems. This paper also summarizes a classification of scheduling problems, and illustrates the design way of EAs for the different types of scheduling problems. It is useful to guide how to design an effective EA for the practical manufacturing scheduling problems. As known, these practical scheduling problems are very complex, and almost is a combination of different typical scheduling problems.     

Effects of Stearic Acid on the Injection Molding of Alumina

This research investigated the influence of stearic acid on the injection molding of alumina, by varying the concentration of stearic acid. The interaction between stearic acid and alumina was identified using transmission infrared spectroscopy, indicating stearic acid preferentially adsorbed onto the alumina powder surface. In addition to slightly modifying the intrinsic binder viscosity, stearic acid adsorbed onto the powder surface changed the flow behavior of the mixtures from dilatant flow to pseudoplastic flow at low temperatures. As a result, inhomogeneous distribution of binder in the injection-molded parts was minimized with increased stearic acid concentration. However, the possibility of forming bubbles in the mixtures arising from vaporization of stearic acid was enhanced. Additionally, the binder burnout temperature range was broadened with the increase of stearic acid concentration.     

计算机辅助试验研究系统

１９８１年我们研制了可在我校４４１Ｂ－Ⅲ和ＤＰＳ８／４９电子计算机上运行的多变量橡胶配方试验程序（ｔ－ｓ），为了微型计算机普遍使用的形势，根据在生产和科学研究中应用统计方法实际情况，我们改写、扩展，组成了计算机辅助试验研究（ＣＯＭＰＵＥＲＡＩＤＥＤ ＲＥＳＥＡＲＣＨ，简称ＣＡＲ）系统，其主要内容包含正交试验法和回归分析法等，具有实验设计、配方（配合）开发、实验拟合模型等功能，可作多因素试验的定性     

Selective oxidation of styrenes under oxygen catalyzed by cobalt chloride

The cobalt(II) chloride-catalyzed oxidative cleavage of -methylstyrene with oxygen in t-BuOH gives acetophenone and formaldehyde in good yield. The competing reactions between C=C cleavage and formation of polymeric products are strongly affected by the solvent, cobalt catalyst and concentration used, as well as the reaction temperature. A free radical mechanism involving a cyclic peroxide intermediate is proposed to give the cleavage products. Oxidation of various alkenes using CoCl₂/t-BuOH/O₂ system shows that only activated styrenes can be oxidized effectively. The reactivity of various styrenes and their selectivity towards giving cleavage products or polymers are strongly influenced by the electronic and steric properties of the substrate.