Heterogeneous Adsorption Characteristics of Volatile Organic Compounds (VOCs) on MCM‐48

Abstract

This work focuses on the fundamental studies of heterogeneous adsorption characteristics of mesoporous adsorbent. MCM‐48 was synthesized to investigate the adsorption properties of eight different volatile organic compounds (benzene, cyclohexane, n‐hexane, toluene, methanol, acetone, methyl ethyl ketone (MEK), and trichloroethylene (TCE)). The gravimetric method was used to measure the adsorption equilibrium amount. Several simple and reliable methods such as isosteric enthalpy of adsorption, thermodynamic properties, condensation pressure, organophilicity, and adsorption energy distribution were evaluated to understand the surface heterogeneity of the VOCs+MCM‐48 adsorption system. This work shows that the unique features of the VOCs+MCM‐48 adsorption system are highly dependent on the adsorption step, ionization potential, and Debye dipole moment of VOCs.     

Hydrogen‐rich gas production from ethanol steam‐reforming reaction using NiZr‐loaded MCM‐48 catalysts at mild temperature

The rich‐hydrogen generation from ethanol steam reforming over NiZr, which is used as an anode material in solid oxide fuel cells, ‐loaded MCM‐48 (NiZr/MCM‐48) catalyst was investigated in this study. We used an impregnation approach to synthesize an MCM‐48 (70.0 wt‐%) support loaded with bimetallic NiZr (30.0‐wt%, Ni:Zr atomic ratio = 4:6, 5:5, and 6:4), and the prepared catalysts were applied to the steam‐reforming reactions of ethanol. These three bimetallic NiZr/MCM‐48 catalysts exhibited significantly higher reforming reactivity than the mono‐metal, Ni‐loaded MCM‐48 (Ni/MCM‐48) catalyst. The hydrogen production was started from 350°C over the three NiZr/MCM‐48 catalysts, compared to above 550°C over the Ni/MCM‐48 catalyst. The catalytic performance was affected by the Zr content. The H₂ production and ethanol conversion were maximized at 85% and 95%, respectively, over Ni₄Zr₆/MCM‐48 at 750°C for 1 h at CH₃CH₂OH:H₂O = 1:1 and a gas hourly space velocity of 4000 h^‐1. This high performance was maintained for up to 60 h. Copyright © 2013 John Wiley & Sons, Ltd.     

Ethylene polymerization with hybrid nickel diimine/Cp2TiCl2 catalyst: a new method to prepare blends of linear and branched polyethylene

Blends of linear polyethylene (LPE) and branched polyethylene (BPE) display very good mechanic properties that can be beneficial for various applications such as shear thinning and melt elasticity. LPE, BPE and amorphous polyethylene can be produced using nickel diimine (DMN) catalyst under various polymerization conditions, while LPE can be obtained using metallocene catalyst. Thus, LPE/BPE blends can be achieved by in situ polymerization using a hybrid DMN/metallocene catalyst. A novel hybrid catalyst made of DMN and Cp₂TiCl₂ was designed and used for ethylene polymerization. A synergistic effect of the two active sites in the hybrid DMN/metallocene catalyst was observed. Blends of linear and low branched polyethylene were synthesized when polymerization was conducted at low temperature (0 °C), while blends of linear and highly branched polyethylene were obtained at high temperature (50 °C). However, the miscibility of the polymers obtained at 50 °C was dramatically reduced as compared to those obtained at 0 °C. Mesoporous particles (MCM‐41) consisting of aluminosilicate with cylindrical pores were used to support the hybrid catalyst, in which MCM‐41 provides sufficient nanoscale pores to facilitate the polymerization in well‐controlled confined spaces. Blends of LPE and BPE were synthesized by in situ polymerization without adding comonomer and characterized. The miscibility of the polymer blends can be improved by supporting the hybrid catalyst on MCM‐41. Copyright © 2009 Society of Chemical Industry     

A Test Methodology for High Performance MCMs

Satellite and avionics applications represent an ideal application for the tremendous performance, cost, space, andreliability benefits of MCMs. These advantages are only realized,however, if accompanied by an efficient test strategy whichverifies defect-free fabrication. This paper describes a methodology developed to test high performance VLSI CMOS ICs thathave been mounted onto a multi-chip silicon substrate. A teststrategy, which addresses testing from the wafer level through tothe populated substrate, is detailed. This strategy uses acombination of LSSD, AC LSSD-On-Chip Self Test, Deterministic Delay Fault Testing, and Design for Partitionability to ensure high testquality at a reasonable cost. The methodology is then contrastedto alternative approaches.     

微电子封装技术的发展趋势

论述了微电子封装技术的现状与未来 ,介绍了微电子封装中几个值得注意的发展动向 ,同时 ,从中可以看出IC芯片与微电子封装技术相互促进 ,协调发展密不可分的关系。     

多芯片组件热阻技术研究

在传统单芯片封装热阻定义的基础上,针对多芯片组件(MCM)传统热阻表示方法的不足,基于线性叠加原理,采用有限元模拟技术,提出了MCM的结到壳的热阻表示方法——热阻矩阵,并利用有限元模拟方法对热阻矩阵进行了验证。结果表明,采用热阻矩阵方法预测器件结温的误差小于2%。     

基于Non-Fourier导热模型的多芯片组件基板热分析研究

随着电子产品的尺寸和重量日趋变小,经典Fourier理论已经不能很好地解决实际问题。为了使理论结果尽可能准确地反映实际情况,需要用到Non-Fourier导热模型。首先,建立了三维多芯片组件的Fourier和Non-Fourier导热模型;其次,采用有限差分方法求解相应模型的传热方程,得到了温度分布和温度响应;最后,使用有限元热分析软件ICEPAK建立了相应的热分析模型并进行计算。实验结果表明,与经典的Fourier模型相比,Non-Fourier模型更加接近实际温度,且温度场进入稳态的时间较长,热耦合的现象也更强。     

MCM-41分子筛负载磷钨钼酸催化合成环已酮1，2-丙二醇缩酮

以MCM-41分子筛负载磷钨钼杂多酸为催化剂，以环己酮和1，2-丙二醇为原料合成了环己酮1，2-丙二醇缩酮，探讨了MCM-41分子筛负载磷钨钼杂多酸催化剂对缩酮反应的催化活性，较系统地研究了原料量比、催化剂用量、反应时间诸因素对缩酮反应的影响。实验表明，MCM-41分子筛负载磷钨钼杂多酸催化剂是合成环己酮1，2-丙二醇缩酮的良好催化剂，在n（环己酮）：n（1，2-丙二醇）=1：1．6，催化剂用量为反应物总质量的0．20％，环己烷作带水剂，反应时间45min的优化条件下，环己酮1，2-丙二醇缩酮的收率可达89．1％。     

Simulation Techniques for the Manufacturing Test of MCMs

Simulation techniques used in the Manufacturing Test SIMulator(MTSIM) are described. MTSIM is a Concurrent Engineering tool used tosimulate the manufacturing test andrepair aspects of boards and MCMs from design concept through manufacturing release. MTSIM helps designers select assemblyprocess, specify Design For Test (DFT) features, select board testcoverage, specify ASIC defect level goals, establish productfeasibility, and predict manufacturing quality and cost goals. A newyield model for boards and MCMs which accounts for theclustering of solder defects is introduced and used topredict the yield at each test step. In addition, MTSIMestimates the average number of defects per board detected at eachtest step, and estimates costs incurred in test execution, faultisolation and repair. MTSIM models were validated withhigh performance assemblies at Hewlett-Packard (HP).     

逻辑与物理相结合的MCM划分神经学习方法

本文提出一种性能驱动的MCM划分神经学习方法．新算法具有如下特点：（1）允许功能设计和布图设计同时进行，（2）划分时，不仅考虑了模块间的逻辑关系，还考虑了MCM的版图结构．（3）具有芯片间连线数目最少和时钟周期最短双重优化目标．（4）能使连线尽可能产生在相邻近的芯片之间．（5）网络的结构合理，学习速度快．