Slow crack growth in blends of HDPE and model copolymers

The resistance to slow crack growth (SCG) was measured in binary blends of high density polyethylene (HDPE) and 5–10% concentrations of model ethylene-butene random copolymers by measuring the time to failure (t_f) under a constant stress intensity. An increase of t_f with the addition of the copolymer if the copolymer could crystallize and the increase was greater the higher branch density. The copolymer with 117 branches/1000C could not crystallize and therefore its blend had a t_f that was less than that of the HDPE. The fracture energies of the blends as determined by their resistance to SCG were compared with the energy by rapid fracture, J_c, as previously measured by Rhee and Crist. It is concluded that SCG is more sensitive to variations in the microstructure than is rapid fracture and that the differences in SCG behavior can be qualitatively explained in terms of the differences in microstructure of the blends. ©1995 John Wiley & Sons, Inc.     

半导体激光泵浦预激光锁模调Q固体激光器研究

报道半导体激光侧面泵浦预激光锁模调Ｑ的Ｎｄ：ＹＡＧ固体板条激光器，预激光锁模调Ｑ的激光脉冲宽度为３６ｐｓ，调Ｑ包纤各心的锁模单脉冲能量超过７μＪ，相应的峰值功率达２００ｋＷ。     

Asymmetric synthesis XXVII: Asymmetric catalytic trimethylsilylcyanation of aldehydes by novel Ti-chiral Schiff base complexes

Enantioselective catalytic trimethylsilylcyanations of aldehydes with 48% to 92% e.e. have been studied using the novel Ti-chiral Schiff base complexes. We have found that the catalyst led to high enantoselectivity when the molar ratio of the Schiff base 1 to Ti(O-i-Pr)₄ was 2:1.     

多个相异性矩阵的数据分析

本文给出了分析多个相异性矩阵的三种方法.首先找到了一种图表示,使我们对所有相异性矩阵有一个总体的了解;其次定义了一个新的相异性矩阵,它可以看作是对所有原始相异性矩阵的一个折衷处理;最后提出了一种MIMU方法.在文中我们还对由上述方法得到的坐标图进行了比较.     

牛血清白蛋白的压电免疫测定及电极的洗脱

在镀银石英晶片上用压电免疫方法测定了０．５～５０ｍｇ／Ｌ范围内的牛血清白蛋白的浓度，得到线性响应；并较全面地研究了压电晶片的回复性使用问题，以０．２ｍｏｌ／Ｌ甘氨酸－盐酸（ｐＨ＝２．０）溶液洗脱时效果较好     

Molecular deposition film of porphyrin and phthalocyanine bearing oppositely charged substituents

Ｔｈｅｆｏｒｍａｔｉｏｎｏｆａｎｅｗｔｙｐｅｏｆｓｅｌｆ＿ａｓｓｅｍｂｌｅｄｍｕｌｔｉｌａｙｅｒｆｉｌｍｓ,ｍｏｌｅｃｕｌａｒｄｅｐｏｓｉｔｉｏｎ(ＭＤ)ｆｉｌｍｓ[1,2],ｉｓａｆａｓｔｄｅｖｅｌｏｐｉｎｇａｒｅａｏｆｔｈｉｎｆｉｌｍｒｅｓｅａｒｃｈ.Ｔｈｉｓｎｅｗｍｅｔｈｏｄｏｆｆｉｌｍｐｒｅｐａｒａｔｉｏｎｉｓｂａｓｅｄｏｎｉｏｎｉｃａｔｔｒａｃｔｉｏｎｂｅｔｗｅｅｎｏｐｐｏｓｉｔｅｃｈａｒｇｅｄｃｈｒｏｍｏｐｈｏｒｅｓ.ＩｎｃｏｍｐａｒｉｓｏｎｗｉｔｈｔｈｅｃｌａｓｓｉｃＬａｎｇｍｕｉｒ＿Ｂｌｏ…     

红磷增效Al（OH）3／Mg（OH）2阻燃的聚丙烯结晶形态

借助宽角Ｘ－射线衍射、差热分析、偏光显微镜对红磷增效Ａｌ（ＯＨ）ａ和Ｍｇ（ＯＨ）２混合填充的阻燃聚丙烯体系的结晶形态进行了研究。发现这种体系中不仅出现ａ型而且还出现β型聚丙烯晶体。β型晶体可能是由于Ａｌ（ＯＨ）ａ和Ｍｇ（ＯＨ）ａ协同诱发而生成的。