硅/钴摩尔比对MCM-48介孔分子筛结构性能的影响

以正硅酸乙酯为硅源、十六烷基三甲基溴化铵为模板、氟化钠为添加剂,水热合成钴掺杂的介孔分子筛(cobalt-containing mesoporous molecular sieve,Co-MCM-48),同时研究合成溶胶中不同摩尔比m(Si):n(Co)对MCM-48介孔材料结构性能的影响.通过X射线粉末衍射、N2吸附...     

溶气气浮-超滤-反渗透深度处理油田污水及回用

根据油田处理污水的现状及面临的主要问题,提出了利用“溶气气浮-超滤-反渗透”法处理油田污水进行配制聚合物再利用的工艺,通过现场试验、分析了各工艺处理前后的水质,并进行了配制的聚合物溶液的初始粘度和稳定性的对比.结果表明,油和SS的质量浓度降至1 mg·L-1以下,出水矿化度降至500 mg·L-1以下,对聚合物影响较大的Ca2+和Mg2+的质量浓度降至5 mg· L-1以下;配制的聚合物溶液粘度和粘度稳定性均有较大地提高.处理后的水可以替代清水配制聚合物母液,具有较好的经济及社会效益.     

生物活性炭深度处理循环水产养殖废水研究

以经过臭氧氧化消毒→机械过滤→生物过滤的养鱼废水为原水,研究了生物活性炭对水产养殖废水中氨氮、亚硝态氮和COD深度处理的效果,并与活性炭吸附处理进行了对比研究.结果表明,在滤速14m·h-1、进水水温23.3～30.3℃、pH为7.35～8.06、溶解氧质量浓度为6.0～8.1 mg·L-1、氨氮质量浓度0.204～0.984mg·L-1、亚硝态氮质量浓度0.090～1.003 mg·L-1、COD为13.44～26.80mg·L-1的条件下,生物活性炭对氨氮、亚硝酸盐氮和COD的平均去除率分别达到85.5%、90.1%和43.8%.经生物活性炭处理后,出水氨氮和亚硝态氮浓度均达到了花鳗养殖对水质的要求,达标率分别为100%和97.6%,可以循环回用;在滤速14m·h-1,低进水氨氮、亚硝态氮浓度下,活性炭吸附对氨氮和亚硝酸盐氮几乎没有去除作用,但对COD的吸附去除率高达52.3%.     

光催化还原CO2反应催化剂的研究进展

温室气体CO2是全球变暖的一个主要原因,利用太阳能将CO2还原为烃类等有机物将给环境保护和能源利用带来益处.介绍了CO2光催化还原反应中的催化剂,主要涉及TiO2、金属配合物以及一些其它金属氧化物.阐述了各类催化剂的制备过程、结构特征、光催化还原CO2反应条件以及催化剂存在的问题.通过催化剂设计,提高光催化反应活性和光...     

微纳叠层复合材料成型口模结构优化

使用Moldex3D模流分析软件对微纳叠层喇叭口模内部熔体的流动情况进行模拟,通过对阻尼块结构和尺寸的优化,分析了口模内部熔体的流动情况,根据熔体横向速度均匀性设计出最佳口模内结构形式,为微纳叠层复合片材制备提供借鉴.     

一种虚拟机系统下关于多级安全的强制访问控制框架II:实现

This paper is a continuation of our last paper [1] which describes the theory of Virt-BLP model. Based on Virt-BLP model, this paper implements a mandatory access control (MAC) framework applicable to multi-level security (MLS) in Xen. The Virt-BLP model is the theoretical basis of this MAC framework, and this MAC framework is the implementation of Virt-BLP model. Our last paper focuses on Virt-BLP model, while this paper concentrates on the design and implementation of MAC framework. For there is no MAC framework applicable to MLS in virtual machine system at present, our MAC framework fills the blank by applying Virt-BLP model to Xen, which is better than current researches to guarantee the security of communication between virtual machines (VMs). The experimental results show that our MAC framework is effective to manage the communication between VMs.     

连续时间Sigma Delta ADC设计和非理想因素分析

文章设计了一个用于物联网模拟基带的、低压、低功耗、宽带、连续时间Sigma Delta ADC,特别是对各种非理想因素（时钟抖动,环路延时,运放有限增益和带宽,比较器offset,DAC失配等）,基于matlab和simulink等工具进行了系统级仿真并得到各种非理想因素对系统性能的影响。电路架构采用3阶3bit前馈加反馈结构,电源电压1.2V,输入信号带宽为16MHz,过采样率为16,采样频率为512MHz。测试结果显示,SNR为60dB,SNDR为59.3dB,总功耗为22mW。     

SOl-based radial-contour-mode micromechanical disk resonator

This paper reports a radial-contour-mode micromechanical disk resonator for radio frequency applications.This disk resonator with a gold plated layer as the electrodes,was prepared on a silicon-on-insulator wafer,which is supported by an anchor on another silicon wafer through Au-Au thermo-compression bonding.The gap between the disk and the surrounding gold electrodes is 100 nm.The radius of the disk is 20 μm and the thickness is 4.5μm.In results,the resonator shows a resonant frequency of 143 MHz and a quality factor of 5600 in vacuum.     

基于ARM的智能化公寓安防测控系统设计

针对宿舍安全需求,遵循可靠性、独立性、安全性、联动性、扩展性、实用性、经济性的原则设计出了一个基于ARM的智能化公寓防盗防火报警系统。该系统采用Easyarm LM3S1138、RS232总线和多种传感器,实现了异地控制和多终端网络同步控制。经测试表明,该系统不仅实现了人体检测、烟雾检测、声光报警、键盘密码解警以及宿舍内贵重物品进出情况记录等功能,且具有电路设计简单、可靠性高、人机交互友好和成本低的特点。     

Analytical approximate periodic solutions for two-degree-of-freedom coupled van der Pol-Duffing oscillators by extended homotopy analysis method

In this study, the extended homotopy analysis method (EHAM) is applied to derive the accurate approximate analytical solutions for multi-degree-of-freedom (MDOF) coupled oscillators. The present paper not only introduces the rationale for the EHAM for MDOF oscillators, but also strengthens the availability of the conventional homotopy analysis method (HAM) in solving complex MDOF dynamical systems. Employing the EHAM for the two-degree-of-freedom (TDOF) coupled van der Pol-Duffing oscillator, the explicit analytical solutions of frequency ?? and displacements x ₁(t) and x ₂(t) are formulated for various initial conditions and physical parameters. To verify the accuracy and correctness of this approach, a number of comparisons are conducted between the results of the EHAM and the numerical integration (i.e. Runge-Kutta) method. It is shown that the third-order analytical solutions of the EHAM agree well with the numerical integration solutions, even if the time variable t progresses to a comparatively large domain in the time history responses.