横向各向同性介质Thomsen近似公式的适用范围

Thomsen为横向各向同性（TI）介质提出的各向异性参数和线性近似公式被广泛采用,但目前对Thomsen近似公式的适用范围的认识仍很模糊。针对这一问题,研究了TI介质P波和SV波Thomsen近似公式最大相对误差随各向异性参数变化的特征以及近似公式的适用范围。研究结果表明,波速比α0/β0=1．5时,在-0．12≤ε≤0.16且-0.16≤δ≤0.24,或｜ε-δ｜〈0.17（ε和δ为正）时,P波相速度近似公式的最大相对误差不超过l％,随着了0／0的增大,适用范围略有扩大。SV波近似公式的精度比P波要低一些,在｜ε｜≤0.1且｜δ｜≤0.14,或｜ε-δ｜〈O．02（ε和占为正）时,SV波相速度平方线性近似公式的最大相对误差不超过1％,随着α0/β0的增大,适用伪范围明显缩小。总体来说,P波近似公式适用范围较大,对一些中等强度的各向异性也适用;SV波近似公式尤其是群速度近似公式适用范围很小,必要时需要使用高阶近似或者精确解。     

渤海湾盆地喜马拉雅运动幕次划分及演化特征

从构造运动的一致性入手,运用构造运动与沉积环境、火山喷发之间的关系,综合各油田对所在坳陷或凹陷的认识,提出渤海湾盆地喜马拉雅运动划分为侯镇幕、济阳幕、东营幕、渤海幕的新观点.指出其在四大沉积期内存在孔二段、沙河街组四-三段、沙河街组一段-东营组三套烃源岩,相比而言沙河街组四-三段的烃源岩分布范围大生烃能力强,整体上具有沉降中心由南向北和由西向东迁移的沉积演化特征.     

国内外500kV断路器保护分析和比较

结合华东电网500 kV继电保护应用技术原则,从重跳分相出口自保持功能实现、沟通三跳实现和重合闸功能实现这3个方面,对目前国内外500kV断路器保护进行分析比较,得出各自的优缺点,并对其不足之处提出修改建议.最后对若干概念进行分析说明,以便相关人员深入理解.     

Large-scale fabrication of bioinspired fibers for directional water collection

Spider-silk inspired functional fibers with periodic spindle-knots and the ability to collect water in a directional manner are fabricated on a large scale using a fluid coating method. The fabrication process is investigated in detail, considering factors like the fiber-drawing velocity, solution viscosity, and surface tension. These bioinspired fibers are inexpensive and durable, which makes it possible to collect water from fog in a similar manner to a spider's web.     

Metal‐containing Polymers via Electropolymerization

Electropolymerization represents a suitable and well‐established approach for the assembly of polymer structures, in particular with regard to the formation of thin, insoluble films. Utilization of monomers that are functionalized with metal complex units allows the combination of structural and functional benefits of polymers and metal moieties. Since a broad range of both electropolymerizable monomers and metal complexes are available, various structures and, thus, applications are possible. Recent developments in the field of synthesis and potential applications of metal‐functionalized polymers obtained via electropolymerization are presented, highlighting the significant advances in this field of research.     

PAN基原丝预氧丝炭纤维微结构的几种新的X射线衍射散射定量表征技术

介绍几种新近开发的针对PAN基原丝、预氧丝和炭丝微结构和结构缺陷的X射线衍射与散射定量表征技术,它们是:纤维材料中柱状(椭球状)纳米取向微孔体积分数X射线小角散射定量表征方法;纤维材料中柱状(椭球状)纳米取向微孔取向角的小角散射定量表征方法;预氧丝中链状相与环化相体积分数的小角衍射定量表征方法以及炭纤维中乱层石墨相与单层石墨相的X射线广角衍射定量表征方法等。