Application of CO2 laser heating zone drawing and zone annealing to nylon 6 fibers

Nlon 6 fibers were zone drawn and zone annealed by using a continuous wave carbon dioxide laser to develop their mechanical properties. A laser‐heating zone drawing was carried out under a applied tension of 35.4 MPa at a power density of 9.65 W · cm^?2, and then the zone‐drawn fiber was annealed. A laser‐heating zone annealing was carried out in two steps at a power density of 9.65 W · cm^?2; the first step was carried out under 423 MPa and the second under 517 MPa. The treating temperature of the fiber heated by the CO₂ laser was measured by using an infrared thermographic camera equipped with a magnifying lens. The treating temperature at the zone drawing is 138°C, and those at the first and the second zone annealing are 121 and 125°C, respectively. The second laser‐heated zone‐annealed fiber has a birefringence of 65.2 × 10^?3, a degree of crystallinity of 54%, and a storage modulus of 21 GPa at 25°C. Wide‐angle X‐ray diffraction patterns for the laser‐heated zone‐drawn and the zone‐annealed fibers show (200) reflection and (002/202) doublet due to only an α form on the equator. The laser‐heated zone‐drawn fiber has a melting endotherm peaking at 216°C and a trace of shoulder on the higher temperature side of its peak, and the laser‐heated zone‐annealed fibers have a single melting endotherm peaking at 216°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1711–1716, 2002     

高硅石灰石在水泥生产中的应用

宁夏赛马实业股份有限公司自备矿山中,有3000万t的高结晶硅石灰石因其对粉磨和煅烧的不利,影响一直没有得到利用。2003年新建2×2500t/d生产线时,该公司从粉磨设备选用,燃烧器选择,配料方案探索等多方面着手,在新线上实现了高硅石灰石的合理利用。     

硅通孔化学机械平坦化中铜去除的电化学与选择性研究

利用极化曲线测量法研究了甘氨酸和过氧化氢浓度及pH对硅通孔(TSV)化学机械平坦化(CMP)中铜腐蚀的影响。结果表明:甘氨酸对铜的腐蚀随其浓度增大而增强;随着过氧化氢浓度增大,铜腐蚀电位逐渐增大;在p H为10时铜的腐蚀效果最佳。CMP实验表明,在不同浓度的甘氨酸和过氧化氢之下,抛光速率可调,达1.9~5.8μm/min,铜表面粗糙度为5~29 nm,铜钽去除速率比为20~50。     

空心微珠在尼龙改性中的应用研究

利用空心微珠球型的特性，填充改性玻纤增强尼龙6。研究结果表明，空心微珠可提高材料流动性、热变形温度及改善制品外观、降低收缩率和提高制品的物理性能。     

氯化N-苄基-4-乙烯基吡啶聚合物的抗菌活性

氯化N-烷基-4-乙烯基吡啶聚合物,简称可溶性PVP,是一类具有高活性、低毒性和诸多潜在的特殊用途的季铵盐抗菌材料.本研究对聚-N-苄基乙烯基吡啶进行了合成与提纯,并对其在不同物理化学条件下抗菌性能差异进行了研究,结果表明温度、溶液条件等因素的变化对于样品的抗菌性能有重大影响.     

气化炉锥底砖、激冷环与下降筒的损毁与解决对策

针对国产化大氮肥水煤浆气化炉中锥底砖、激冷环和下降筒使用过程中出现的问题,分析了损毁原因,分别从技术改进、工艺操作和设备管理等方面提出了相应的解决对策,可以不同程度地延长锥底砖、激冷环、下降筒的寿命。     

Zn-Ni合金共沉积影响机理的拉曼光谱研究

首次利用现场表面增强拉曼光谱研究了Zn-Ni合金共沉积的机理。通过研究Ni电极在NiCl2溶液与纯水中的拉曼光谱、Ni电极与Au电极在KCl溶液中的拉曼光谱以及这2种电极在NiCl2溶液中现场电沉积的拉曼光谱,并根据前人提出的理论,得出如下结论:Zn-Ni合金共沉积中存在着较易在电极表面放电的NiClad,使Ni沉积的过电位降低,促进了Ni的沉积,导致Zn的异常共沉积。     

Partial oxidation of methane to synthesis gas over α-Al2O3-supported bimetallic Pt–Co catalysts

The partial oxidation of methane to synthesis gas was studied at atmospheric pressure and in the temperature range of 550–800°C over -Al₂O₃-supported bimetallic Pt–Co, and monometallic Pt and Co catalysts, respectively. Both methane conversion and CO selectivity over a bimetallic Pt_0.5Co₁ catalyst were higher than those over monometallic Pt_0.5 and Co₁ catalysts. Furthermore, the addition of platinum in Pt–Co bimetallic catalysts effectively improved their resistance to carbon deposition with no coking occurring on Pt_0.5Co₁ during 80 h reaction. The FTIR study of CO adsorption observed only linearly bonded CO on bimetallic Pt–Co catalysts. TPR and XPS showed enhanced formation of a cobalt surface phase (CSP) in bimetallic Pt–Co catalysts. The origins of the good coking resistivity of bimetallic Pt–Co catalysts were discussed.     

竖向荷载作用下斜桩承载特性数值分析

近年来,斜桩在桥梁、码头、海上钻井平台及大型输电线路塔架基础等工程中得到广泛应用,研究不同倾角斜桩的荷载传递及承载特性实用意义较大。基于ABAQUS软件,考虑桩土接触特性,模拟分析了不同倾角斜桩的承载特性。结果表明:桩身倾角不大于10°时,倾斜角对单桩的极限承载力影响不大,但会在桩身产生一定弯矩以及桩顶产生一定的水平位移;桩身轴力沿桩长方向的衰减速率随桩身倾角的增大而增大;斜桩桩身弯矩主要分布在桩顶下1/2桩长范围内,其最大值的位置不受桩身倾角以及桩顶竖向荷载的影响;斜桩桩身侧摩阻力沿桩长大致呈"S"型分布,其桩顶以下1/6桩长范围内侧摩阻力远远大于直桩。