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CATALYTIC ACTIVITIES OF RARE-EARTH CALIXARENE COMPLEXES IN POLYMER SYNTHESES

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Chinese Journal of Polymer Science 2005年第6期23卷 593-602页

作者： zhi-quan shen Institute of Polymer Science Zhejiang University Hangzhou 310027 China

The studies of our group on the catalytic activities of rare earth calixarene complexes in polymer syntheses are reviewed. Rare earth calixarene complexes are effect catalysts for the polymerizations of butadiene, isoprene, ethylene, styrene, propylene oxide, styrene oxide, trimethylene carbonate and 2,2-dimethyl-trimethylene carbonate.

关键词： Rare earth complex Calixarene Polymer synthesis.

C^1 natural element method for strain gradient linear elasticity and its application to microstructures

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Acta Mechanica Sinica 2012年第1期28卷 91-103页

作者： zhi-Feng Nie shen-Jie Zhou Ru-Jun Han Lin-Jing Xiao kai Wang College of Mechanical and Electronic Engineering Shandong University of Science and Technology266510 QingdaoChina School of Mechanical Engineering Shandong University250061 JinanChina Department of Scientific Research Shandong University of Science and Technology266510 QingdaoChina Jinan Vocational and Technical College in Engineering 250200 JinanChina

C^1 natural element method （C^1 NEM） is applied to strain gradient linear elasticity, and size effects on mi crostructures are analyzed. The shape functions in C^1 NEM are built upon the natural neighbor interpolation （NNI）, with interpolation realized to nodal function and nodal gradient values, so that the essential boundary conditions （EBCs） can be imposed directly in a Galerkin scheme for partial differential equations （PDEs）. In the present paper, C^1 NEM for strain gradient linear elasticity is constructed, and sev- eral typical examples which have analytical solutions are presented to illustrate the effectiveness of the constructed method. In its application to microstructures, the size effects of bending stiffness and stress concentration factor （SCF） are studied for microspeciem and microgripper, respectively. It is observed that the size effects become rather strong when the width of spring for microgripper, the radius of circular perforation and the long axis of elliptical perforation for microspeciem come close to the material characteristic length scales. For the U-shaped notch, the size effects decline obviously with increasing notch radius, and decline mildly with increasing length of notch.

关键词： Strain gradient linear elasticity C^1 natural element method Sibson interpolation Microstructures Size effects

Ultrasound enhancement of the reduction of the Basic Green dye in wastewater by cast iron

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Journal of Environmental Sciences 2006年第1期18卷 1-3页

作者： shen Zhuang-zhi shen Jian-zhong Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China

Dyes in wastewater are of particular environmental concern since they give an undesirable color to the waters, dye and their derivatives are harmful to human health and the environment （ Annadurai et al., 2002）. Due to their biological persistency, conventional biological treat-ment processes such as activated sludge process are ineffective for their removal（Shaul et al., 1991）. There is a need to develop effective methods for the degradation of such persistent organic pollutants, either to less harmful compounds or, more desirable, to their complete mineralization.

关键词： cast iron ultrasound Basic Green combined effect

Theoretical estimation of sonochemical yield in bubble cluster in acoustic field

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Chinese Physics B 2020年第1期29卷 357-365页

作者： Zhuang-zhi shen School of Physics&Information Technology Shaanxi Normal UniversityShaanxi Key Laboratory of UltrasonicsXi'an 710119China

In order to learn more about the physical phenomena occurring in cloud cavitation,the nonlinear dynamics of a spherical cluster of cavitation bubbles and cavitation bubbles in cluster in an acoustic field excited by a square pressure wave are numerically investigated by considering viscosity,surface tension,and the weak compressibility of the *** theoretical prediction of the yield of oxidants produced inside bubbles during the strong collapse stage of cavitation bubbles is also *** effects of acoustic frequency,acoustic pressure amplitude,and the number of bubbles in cluster on bubble temperature and the quantity of oxidants produced inside bubbles are *** results show that the change of acoustic frequency,acoustic pressure amplitude,and the number of bubbles in cluster have an effect not only on temperature and the quantity of oxidants inside the bubble,but also on the degradation types of pollutants,which provides a guidance in improving the sonochemical degradation of organic pollutants.

关键词： bubble cluster models bubble cluster dynamics chemical kinetics bubble temperature strong oxidants acoustic cavitation

Cracking Behavior in Additively Manufactured Pure Tungsten

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Acta Metallurgica Sinica(English Letters) 2019年第1期32卷 127-135页

作者： Dian-Zheng Wang kai-Lun Li Chen-Fan Yu Jing Ma Wei Liu zhi-Jian shen State Key Laboratory of New Ceramic and Fine Processing School of Materials Science and Engineering Tsinghua University Department of Materials and Environmental Chemistry Arrhenius Laboratory Stockholm University

In this study, near fully dense(96.5%) pure tungsten bulks were additively manufactured and the cracking behavior was investigated. A crack network with a spacing of ～100 lm was observed in the fabricated bulks. It was observed that the laser scanning strategy, which could tailor the microstructure, affected the crack distribution pattern in fabricated *** calculated surface temperature difference(7300 K) was much higher than the cracking criterion(800 K) of tungsten,indicating that cracking is almost inevitable in laser additive manufacturing of tungsten. It could be concluded that crack network formed because the cracks emerged in every laser molten track and then interconnected in the layer-by-layer building process.

关键词： Tungsten Selective laser melting Cracking Microstructure

Hyperfine Constants for Low-Lying States in ^137Ba^＋

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Communications in Theoretical Physics 2007年第5X期48卷 913-916页

作者： YU kai-zhi School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510631 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics The Chinese Academy of Sciences Wuhan 430071 China

Relativistic many-body perturbation calculation is applied to calculate the hyperfine constants for the lowlying states 6S1/2, 6P1/2, 6P3/2, 5D3/2, and 5D5/2 in the alkaline earth ion ^137Ba^＋. The zeroth-order hyperfine constants are calculated with Dirac-Fock wave functions, and the finite basis sets of the Dirac-Fock equation are constructed by B splines. With the finite basis sets, the core polarization and the correlation effect are calculated. The final results for magnetic dipole hyperfine a constants are obtained.

关键词： hyperfine structure hyperfine interactions ab initio calculations

Recent progress in the design and fabrication of MXene-based membranes

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Frontiers of Chemical Science and Engineering 2021年第4期15卷 820-836页

作者： kai Qu Kang Huang zhi Xu State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China

Two-dimensional membranes have attracted significant attention due to their superior characteristics,and their ability to boost both flux and selectivity have led to their reputation as potential next-generation separation *** them,emerging MXene-based membranes play significant roles in the competitive membrane-separation *** this mini-review,we systematically discuss the assembly and separation mechanisms of these ***,we highlight strategies based on the crosslinking of MXene nanosheets and the construction of additional nanochannels that further enhance the permeabilities and anti-swelling properties of MXene-based membranes and meet the requirements of practical applications,such as gas-molecule sieving,ion sieving,and other small-molecule *** nanosheets can also be used as additives that introduce specific functionalities into hybrid *** addition,extended applications that use MXenes as scaffolds are also discussed.

关键词： MXene 2D materials membranes separation

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地下综合管廊天然气泄漏扩散及爆炸研究综述

灾害学 2025年第1期40卷 129-134页

作者：沈静杜胜群李昕岳杨凯吕鹏飞北京石油化工学院安全工程学院并氢能研究中心北京102617

该文针对城市地下综合管廊燃气舱内的天然气泄漏、扩散以及火灾爆炸风险等问题开展综述分析。关于燃气舱内天然气管线的泄漏研究,必须充分考虑泄漏孔的位置、尺寸、管道工作压力即管线内压强变化、通风和气体探测器报警时限等影响,当舱... 详细信息

该文针对城市地下综合管廊燃气舱内的天然气泄漏、扩散以及火灾爆炸风险等问题开展综述分析。关于燃气舱内天然气管线的泄漏研究,必须充分考虑泄漏孔的位置、尺寸、管道工作压力即管线内压强变化、通风和气体探测器报警时限等影响,当舱室天然气大量泄漏后,仅增加通风次数无法有效防止天然气积聚,必须同时启用舱内防火门进行截断隔离措施。分析受限空间内气体爆炸已有的研究进展,结果表明,针对燃气舱天然气泄漏爆炸的模拟研究,应充分考虑管廊长径比及舱内物体的影响;且爆炸冲击波强度较高,需采用相应的防爆抑爆措施。本文为城市地下综合管廊中天然气管道运输的安全性研究提供了方向和参考。

关键词：综合管廊燃气舱泄漏扩散爆炸报警响应

Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： zhi-Lin shen Jian-Jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method