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51.
Wenlin Zhang Xiaoqing Wang Guangqiu Shen Dezhong Shen 《Crystal Research and Technology》2012,47(2):163-168
A single crystal of Te2V2O9 with dimensions of 15×15×5 mm3 has been grown by the top‐seeded growth method. Infrared and transmission spectra indicate the transmission cutoff wavelength of Te2V2O9 crystal is about 620 nm in visible region and 6.2 μm in infrared region. In addition, band structure and density of states calculations of Te2V2O9 were carried out using the total‐energy code CASTEP based on density functional theory. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
52.
We introduce certain spherically symmetric singular Ricci solitons and study their stability under the Ricci flow from a dynamical PDE point of view. The solitons in question exist for all dimensions n + 1 ≥ 3, and all have a point singularity where the curvature blows up; their evolution under the Ricci flow is in sharp contrast to the evolution of their smooth counterparts. In particular, the family of diffeomorphisms associated with the Ricci flow “pushes away” from the singularity causing the evolving soliton to open up immediately becoming an incomplete (but non-singular) metric. The main objective of this paper is to study the local-in time stability of this dynamical evolution, under spherically symmetric perturbations of the singular initial metric. We prove a local well-posedness result for the Ricci flow in suitably weighted Sobolev spaces, which in particular implies that the “opening up” of the singularity persists for the perturbations as well. 相似文献
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四元数向量和矩阵的秩 总被引:6,自引:0,他引:6
在四元数和四元数向量、矩阵空间上引入三种不同的实表示法则,将四元数列向量的左右线性相关性问题转换成实数域上向量的线性相关问题,由此获得用实矩阵的秩代替四元数矩阵列左秩和列右秩计算方法,同时得出四元数矩阵可逆的一些充要条件和一些新的四元数行列式定义. 相似文献
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1前言高温风洞的温度高达1700℃,流速达0.9马赫数。为了测量风洞中气流温度分布的均匀性,通常采用铂铑30-铂铑10热电偶温度传感器,但是它只能采用逐点移测法,因此它不可能在同一时刻将一条检测线上气流温度测量出来。同时在高温气流测量时,热电偶接点由... 相似文献
59.
Dr. Ya-Nan Zhou Dr. Haiyang Yong Rui Guo Kaixuan Wang Dr. Zhili Li Prof. Weibo Hua Prof. Dezhong Zhou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(7):e202319003
To date, significant efforts have been dedicated to improve their ionic conductivity, thermal stability, and mechanical strength of solid polymer electrolytes (SPEs). However, direct monitoring of physical and chemical changes in SPEs is still lacking. Moreover, existing thermosetting SPEs are hardly degradable. Herein, by overcoming the limitation predicted by Flory theory, self-reporting and biodegradable thermosetting hyperbranched poly(β-amino ester)-based SPEs (HPAE-SPEs) are reported. HPAE is successfully synthesized through a well-controlled “A2+B4” Michael addition strategy and then crosslinked it in situ to produce HPAE-SPEs. The multiple tertiary aliphatic amines at the branching sites confer multicolour luminescence to HPAE-SPEs, enabling direct observation of its physical and chemical damage. After use, HPAE-SPEs can be rapidly hydrolysed into non-hazardous β-amino acids and polyols via self-catalysis. Optimized HPAE-SPE exhibits an ionic conductivity of 1.3×10−4 S/cm at 60 °C, a Na+ transference number ( ) of 0.67, a highly stable sodium plating-stripping behaviour and a low overpotential of ≈190 mV. This study establishes a new paradigm for developing SPEs by engineering multifunctional polymers. The self-reporting and biodegradable properties would greatly expand the scope of applications for SPEs. 相似文献
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Pingxuan Jiao Shouxin Wang Shuobin Liang Man Li Qianqian Gao Dezhong Ji Yingying Chen Haiwei Li Fuxiang Ran Yongmin Zhang Lihe Zhang Demin Zhou Sulong Xiao 《中国化学快报》2019,30(3):690-693
Four water-soluble β-CD-pentacyclic triterpene conjugates were synthesized via ester and amide linkages. All the conjugates showed lower hydrophobicity (AlogP) than their parent. 相似文献