EA-HFCVD 沉积纳米金刚石膜的光致发光分析

采用电子辅助-热丝化学气相沉积法(EA-HFCVD)在硅片上沉积出晶粒尺寸为30nm的均匀金刚石膜。生长过程中,预先加6A偏流生长1h,然后在0.8kPa条件下,无偏流生长3h。光致发光谱中存在4个发光中心分别位于1.682eV,1,564eV,1,518eV和1.512eV的发光峰。1.682eV处发光峰源于衬底硅原子掺杂于膜中引起的缺陷;其他发光峰源于金刚石晶格振动声子。光致发光强度越大对应的缺陷密度越大,从而降低了场发射域值电场强度,其关键可能源于金刚石膜电导型晶界。     

硅芯制备技术及对沉积多晶硅棒杂质的影响

本文介绍了改良西门子法多晶硅生产中的硅芯制备技术,包括区熔法硅芯制备技术和切割法硅芯制备技术。简要介绍了两种硅芯制备技术的工艺流程,并对两种不同技术路线制备硅芯过程中的杂质分凝、挥发及坩埚污染进行了比较。根据分析结果,采用区熔硅芯能在一定程度上降低硅芯对硅棒的杂质贡献。     

Flow and thermal characteristics of cationic dyeable nylon 6/cationic dyeable poly(ethylene terephthalate) polyblended polymers and filaments

Cationic dyeable nylon 6 (CD‐N6) and cationic dyeable poly(ethylene terephthalate) (CD‐PET) polymers were extruded (in the proportions of 75/25, 50/50, 25/75) from one melt twin‐screw extruders to prepare three CD‐N6/CD‐PET polyblended polymers and then spin filaments. The molar ratio of 5‐sodium sulfonate dimethyl isophthalate (5‐SSDMI) for CD‐N6 and CD‐PET polymers were 2.01% and 2.04%, respectively. This study investigated the flow and thermal characteristics of CD‐N6/CD‐PET polyblended polymers and filaments using gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), potentiometer, a rheometer, the density gradient, wide‐angle X‐ray diffraction (WAXD), and extension stress–strain measurement. Flow behavior of CD‐N6/CD‐PET polyblended polymers exhibited negative‐deviation blends (NDB), and the 50/50 blend of CD‐N6/CD‐PET showed a minimum value of the melt viscosity. Experimental results of the DSC indicated CD‐N6 and CD‐PET molecules formed an immiscible system. Particularly, a double endothermic peak was observed from CD‐N6, CD‐PET and their polyblended filaments. The tenacity of CD‐N6/CD‐PET polyblended filaments decreased initially and then increased as the CD‐PET content increased. Crystallinities and densities of CD‐N6/CD‐PET polyblended filaments were the linear relation with the blend ratio. The miscibility parameter μ values of CD‐N6/CD‐PET all samples were less than zero. It indicated the electrostatic repulsion was evident between CD‐N6 and CD‐PET molecules. From the experimental data, the CD‐N6 and CD‐PET polymers were identified to be immiscible. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2049–2056, 2007     

全球弹性纤维工业的前景

2007年早期开始，弹性纤维在许多方面已明显发出了下滑趋势信号，目前的全球金融危机可能加剧了这个问题。即使新的投资者相信他们可以替代现有的供应商，但也有必要研究严重的中期需求和供应的趋势，关注这种趋势同样不可回避全球经济形势中的当前问题，这样可使弹性纤维从当前状态更快地得到恢复。     

Catalytic dissociation of hydrogen on a tantalum carbide filament in the HFCVD of diamond

New experimental results are presented which describe the behaviour of a carburised tantalum (TaC) filament in the HFCVD of a diamond film. An abrupt filament temperature drop is observed which is associated with the transition of the filament surface from poisoned to clean. By measuring the power increase needed to compensate for the temperature drop at a wide range of temperatures and corresponding CH₄ concentrations, and also considering the difference in radiative cooling of the filament, an energy balance is established. From this energy balance the production rate for H atoms by catalytic dissociation is obtained. It is found to increase from a level of about 3.8×10²⁰ cm⁻² s⁻¹ at 2200 °C to about 1.6×10²¹ cm⁻² s⁻¹ at 3000 °C. This increase, by a factor of 4.5, is somewhat lower than the increase in growth rate observed over the same temperature interval. The difference in these increase factors is interpreted as suggesting that thermal dissociation of H₂ plays a substantial role for H-atom production along with catalytic dissociation.     

高电阻电热合金扁丝面积修正系数的验证

高电阻电热合金扁丝的每米电阻值和电阻率是生产、检验和使用过程中的重要技术参数，其相互换算与材料的横截面积有关。高电阻电热合金扁丝是由圆丝轧制而成，属不切边型，宽度乘厚度的矩形面积和实际面积间的关系由面积修正系数来决定。我国一直沿用瑞典康太尔公司的０９２系数计算电阻率和每米电阻值，其误差太大。通过实验测算法对系数进行了验证，验证结果表明，系数取０９６更接近于实际，精确度达万分之几。     

温州华峰集团1000吨／年氨纶工程空调通风系统设计

针对氨纶工程工艺的特点，介绍该工程中空调通风系统的设计原则及系统配置情况。