Higher-order Nonlinear System of Equations of Changing Type

In practical problems there appears higher-order equations of changing type([1]). But, there are only a few of papers concerning this type of equations ([2]-[6]). In this paper, the global existence of regular solutions to the Initial-boundary value problem for a class of higher-order system of equations of changing type with a strong nonlinear term is studied.     

中低温下钠碱对氢氧化钙干式吸收HCl气体的改良

用很稀的NaOH、Na2CO3、NaCl溶液代替纯水消化生石灰,测试并比较生成的Ca（OH）2与不含这些物质的Ca（OH）2在中低温段（200～300℃）净化酸性气体HCl的反应能力．试验表明用钠碱NaOH和Na2CO3溶液消化生成的Ca（OH）2较用纯水和NaCl溶液消化生成的Ca（OH）2具有更高的反应能力,即钠碱对Ca（OH）2具有改良作用．初步研究表明,含有钠碱的氢氧化钙反应能力较高的主要原因有：（1）孔容积和比表面积提高;（2）孔隙率分布改善,最佳孔径区（50～200A）内的BJH孔隙率和比表面积递增密度增大;（3）反应产物层疏松多孔,减少了扩散阻力．     

τ→π~±2π~0v结构函数的测量

首次对τ→π2π0v衰变的结构函数进行了模型无关的实验测量,并与KS模型、IMR模型和Feindt模型进行了比较,在误差范围内,三种理论模型与实验结果一致．与OPAL组测量的τ→3π±v道的结构函数相比,在0．5＜Q2＜2．75GeV2范围内未发现明显差异．     

Resonance Scattering Spectral Detection of Catalase Activity Using Au@Ag Nanoparticle as Probe and Coupling Catalase Catalytic Reaction with Fenton Reaction

The Au_coreAg_shell (Au@Ag) nanoparticles in size of 30 nm were prepared using 10 nm gold nanoparticles as seeds at 90°C, and were purified by high-speed centrifugation to remove the excess trisodium citrate to obtain Au@Ag nanoprobe. In the medium of pH 4.0 acetate buffer solution—7.2 μmol/L H₂O₂–67 μmol/L Fe(II), Au@Ag nanoparticles exhibited a resonance scattering (RS) peak at 538 nm. Upon addition of Catalase (Ct), the system produced hydroxyl radical that oxidized the Au@Ag nanoprobe to form the AuAg nanoparticles with partly bare nanogold. Those AuAg nanoparticles aggregated to large nanoclusters that led to the RS peak wavelength red-shift and its RS peak intensity enhanced. The catalase activity (C) is linear to the enhanced RS intensity (ΔI) in the range of 6 to 2,800 U/L, with regression equation of ΔI = 0.168 C-0.2, the correlation coefficient of 0.9952, and detection limit of 2.8 U/L. This method was applied to the detection of serum samples, and the results were agreement with that of the spectrophotometry. A new catalytic mechanism of catalase was proposed with oxywater principle that was agreement with the results of resonance scattering spectroscopy, absorption spectrophotometry, transmission electron microscopy and laser scattering.     

Non-invasive monitoring of fouling in hollow fiber membrane via UTDR

Fouling is the most critical problem associated with membrane separations in liquid media. But it is difficult to control the inevitable membrane fouling because of its invisibility, especially on the inside surface of hollow fiber membranes. This study describes the extension of ultrasonic time-domain reflectometry (UTDR) for the real-time measurement of particle deposition in a single hollow fiber membrane. A transducer with a frequency of 10 MHz and polyethersulfone hollow fiber membranes with 0.8 mm inside diameter (ID) and 1.2 mm outside diameter (OD) were used in this study. The fouling experiments were carried out with 1.8 g/L kaolin suspension at flow rates 16.7 and 10.0 cm/s. The results show that UTDR technique is able to distinguish and recognize the acoustic response signals generated from the interfaces water/upper outside surface of the hollow fiber, lumen upside surface/water, water/lumen underside surface and lower outside surface/water in the single hollow fiber membrane module in pure water phase. The systemic changes of acoustic responses from the inside surfaces of the hollow fiber in the time- and amplitude-domain with operation time during the fouling experiments were detected by UTDR. It is associated with the deposition and formation of the kaolin layer on the inside surfaces. Further, the acoustic measurement indicates that the deposited fouling layer is denser on the lumen underside surface of the hollow fiber than that on the lumen upside surface as a result of weight. Moreover, it is found that the fouling layer grows faster on the inside surface of the hollow fiber at a flow rate of 10.0 cm/s than that at 16.7 cm/s due to the lower shear stress. The fouling layer formed is thicker at a flow rate of 10.0 cm/s than that at 16.7 cm/s. The flux decline data and SEM analysis corroborate the ultrasonic measurement. Overall, this study confirms that UTDR measurement will provide not only a new protocol for the observation of hollow fiber membrane fouling and cleaning, but also a quantitative approach to the optimization of the membrane bioreactor system.     

无约束修正Timoshenko梁的冲击问题

介绍了修正后的Timoshenko梁运动方程,并比较了修正Timoshenko梁与经 典Timoshenko梁的运动方程. 推导了考虑剪切变形引起的转动惯量的修正Timoshenko 梁的正交条件,推导了集中质量对无约束修正Timoshenko梁的正碰撞对梁所引起的瞬态冲 击响应公式,并用算例进行了分析,且与集中质量对经典的无约束Timoshenko梁的正碰撞 对梁所引起的冲击响应进行了比较,另外还用算例分析了梁的刚度的变化和冲击质量比对其 冲击响应产生的影响.     

多孔陶瓷板中城市燃气预混燃烧的试验研究与数值计算

符号表尸可燃混合气体的密度。可燃混合气体的流速。轴向距离。Stefan－Boltzmann常数Tg混合气体的温度R通用气体常数ho多孔陶瓷材料的导热系数DO单元体的内径J单元体的壁厚Tin燃气入口端面的环境温度几单元体的壁温P混合气体压力Te。烟气出口端面的环境温度HO对流换热系数l单元体轴向全长。’积分变量A板面面积。板面孔的数量1引言多孔陶瓷板中的燃气预混燃烧具有热效率高，污染物排放量低的特点，符合九十年代人们对燃烧的要求，因此对多孔陶瓷板中的可燃气体的预混燃烧的研究逐渐成为了国际上的一个热点。目前国内有些厂家己在生产…     

Characteristic length of dynamic glass transition based on polymer/clay intercalated nanocomposites

The glass transition is an old physical problem. It has been accepted that there is a cooperatively rearranging region related to dynamic heterogeneity when temperature approaches the glass transition. However, there is no consensus with the characteristic length and the size of cooperatively rearranging region. This paper first employs the clay gallery in polymer/clay intercalated nanocomposites as a confined two-dimensional (2D) space to assess the characteristic length of dynamic glass transition. The five kinds of clays with different d-spacings were used to investigate the confinement effect. Theoretical calculation based on Donth's formula suggests that the characteristic lengths of polyol and polyol-based polyurethane are ∼3.20 and ∼1.45 nm, respectively. The experimental results agree with theoretical prediction using Donth's formula. The characteristic length varies with polymer types.