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Study on impact factors of tracer gas method in investigations of gaseous pollutant transport and building ventilation

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Building Simulation 2023年第3期16卷 413-426页

作者： Naiping Gao Ruge Wang Yan wu zhu wu School of Mechanical Engineering Tongji UniversityShanghai201804China Baoye Group Co.LTD Zhejiang312000China

Building ventilation is essential to discharge indoor pollutants and improve indoor air quality for occupant *** gas method is an efficient way in the field of building ventilation to measure ventilation rate and to evaluate the ventilation *** shows notable deviation of measured ventilation rate using different tracer *** the present study,CFD simulations are carried out to analyze He-,CO_(2)-and SF_(6)-based tracer gas *** effects of tracer gas density and release rate on the concentration distribution and ventilation effectiveness are *** application scenarios of different ventilation rates and airflow distribution forms are *** results show that the deviation of ventilation effectiveness evaluated by different tracer gases can be above 2-4 times,and the error is introduced by non-passive *** tracer gas dispersion is passive or not depends on the relative importance of density difference driven mass transfer to forced convection mass transfer,which is due to the combined effects of density difference,release rate,and indoor airflow velocity,and can be judged by a dimensionless number θ.Under the geometry and ventilation settings in the present study,the critical value of θ is 1.0 for the error range of 5%,and 2.0 for the error range of 10%.When θ is below the critical value,the gas transport is passive and dominated by the indoor ventilation airflow.A release of tracer gas with smaller release rate and smaller density difference into a stronger indoor airflow behaves more *** tracer gas tends to significantly overestimate the performance of upper supply and lower exhaust ventilation,and lighter tracer gas aggravates the overestimation of the performance for lower supply and upper exhaust *** mechanical ventilation rooms with air change rate of 3.0-6.0 h^(−1),a continuous release of tracer gas SF_(6),CO_(2) or He with release rate above 8 mg/s or source concentrati

关键词： building ventilation tracer gas method passive dispersion non-passive dispersion ventilation effectiveness

Thermal insulation design of subsea vertical X-mas tree

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Petroleum Science 2021年第4期18卷 1182-1194页

作者： Xin Rong Hong-wu zhu College of Mechanical and Transportation Engineering China University of PetroleumBeijing102249China

Temperature drop is commonly observed in subsea vertical X-mas trees during *** presence of a huge temperature difference between internal crude oil and external seawater can cause severe equipment degradation of the oil flow channel(e.g.,hydrate precipitation),which can block the oil flow channel and interrupt the production *** most vulnerable parts of a subsea vertical X-mas tree tend to be components with high convective heat transfer rates,such as production modules and short *** proposed an innovative approach for the insulation design of underwater equipment under a shutdown ***,we obtained a heat transfer analysis of the tree under working conditions through computational fluid dynamics to ascertain the initial temperature condition for an unsteadystate ***,we investigated the unsteady heat transfer characteristics of the tree with an insulation layer in the shutdown state and derived the relationships between insulation duration and thickness by data *** used data analysis to identify the relationship between insulation duration and ***,we derived the empirical formula of insulation thickness for underwater equipment given the effect of environmental factors on the heat preservation *** performed the experiment with an oil pipeline,and the results showed that the internal oil of the equipment did not hydrate within 8 h under the shutdown condition with insulation layers.

关键词： Subsea vertical X-mas tree Thermal insulation design Unsteady heat-transfer analysis Computational fluid dynamics

A Survey of Newtonian Core-Shell Systems with Pseudo High Order Symplectic Integrator and Fast Lyapunov Indicator

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Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 601-610页

作者： Jun-Fang zhu Xin wu Da-zhu Ma Department of Physics Nanchang University Nanchang 330031

Newtonian core-shell systems, as limiting cases of relativistic core-shell models under the two conditions of weak field and slow motion, could account for massive circumstellar dust shells and rings around certain types of star remnants. Because this kind of systems have Hamiltonians that can be split into a main part and a small perturbing part, a good choice of the numerical tool is the pseudo 8th order symplectic integrator of Laskar ＆ Robutel, and, to match the symplectic calculations, a good choice of chaos indicator is the fast Lyapunov indicator （FLI） with two nearby trajectories proposed by wu, Huang ＆ Zhang. Numerical results show that the FLI is very powerful when describing not only the transition from regular motion to chaos but also the global structure of the phase space of the system.

关键词： celestial mechanics - chaos - methods: numerical

Recent advances in visible-light-driven organic reactions

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National Science Review 2017年第3期4卷 359-380页

作者： Qiang Liu Li-zhu wu State Key Laboratory of Applied Organic Chemistry Lanzhou University Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of Sciences

In recent years, visible-light-driven organic reactions have been experiencing a significant renaissance in response to topical interest in environmentally friendly green chemical synthesis. The transformations using inexpensive, readily available visible-light sources have come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In this review, we focus on recent advances in the development of visible-light-driven organic reactions, including aerobic oxidation, hydrogen-evolution reactions, energy-transfer reactions and asymmetric reactions. These key research topics represent a promising strategy towards the development of practical, scalable industrial processes with great environmental benefits.

关键词： visible light catalysis synthesis photocatalyst aerobic oxidation hydrogen evolution energy transfer asymmetric photoreaction

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基于AI专线传输电路约束路径计算的应用

信息技术 2024年第1期48卷 141-145,151页

作者：舒宇朱武增韩笑中国通信建设第二工程局有限公司西安710119 中国移动通信设计院有限公司黑龙江分公司哈尔滨150080

近年来运营商专线业务竞争进入白热化阶段,对专线开通的时效性、准确性要求越来越高,传统的人工方式无法应对专线业务传输电路相关数据制作竞争的要求。文中通过对传输电路约束路径计算方法进行研究,并将算法工具化。基于AI分析的专线... 详细信息

近年来运营商专线业务竞争进入白热化阶段,对专线开通的时效性、准确性要求越来越高,传统的人工方式无法应对专线业务传输电路相关数据制作竞争的要求。文中通过对传输电路约束路径计算方法进行研究,并将算法工具化。基于AI分析的专线传输电路约束路径计算工具能够对接传输工作台相关数据作为数据库,通过研发数据库上的关联规则算法对专线传输电路业务路径进行规划,实现电路调度自动开通,提供完整电路的开通、调整、停闭流程,保障业务的快速开通、提高专线开通的时效性和准确性。

关键词：专线约束路径路由

An advanced higher-order theory for laminated composite plates with general lamination angles

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Acta Mechanica Sinica 2011年第5期27卷 720-729页

作者： Zhen wu Hong zhu Wan-Ji Chen Key Laboratory of Liaoning Province forComposite Structural Analysis of Aerocraft and Simulation Shenyang Aerospace University 110136 Shenyang China

This paper proposes a higher-order shear deformation theory to predict the bending response of the laminated composite and sandwich plates with general lamination *** proposed theory a priori satisfies the continuity conditions of transverse shear stresses at ***,the number of unknown variables is independent of the number of *** first derivatives of transverse displacements have been taken out from the inplane displacement fields,so that the C 0 shape functions are only required during its finite element *** to C 0 continuity requirements,the proposed model can be conveniently extended for implementation in commercial finite element *** verify the proposed theory,the fournode C 0 quadrilateral element is employed for the interpolation of all the displacement parameters defined at each nodal point on the composite *** results show that following the proposed theory,simple C 0 finite elements could accurately predict the interlaminar stresses of laminated composite and sandwich plates directly from a constitutive equation,which has caused difficulty for the other global higher order theories.

关键词： Laminated and sandwich composites Higherorder theory C 0 continuity requirement Transverse shear stress

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带自适应谐波补偿功能的光伏并网控制策略

控制工程 2024年第1期31卷 10-17页

作者：朱武王浩然杨可欣冯天波上海电力大学电子与信息工程学院上海200090 国网上海市电力公司信息通信公司上海200122

为了使含有源电力滤波器(active power filter,APF)功能的光伏并网逆变器在指令电流超过逆变器的限值时具有良好的谐波补偿效果,分析了传统比例式限流和指令电流跟踪方法的不足,提出了一种自适应谐波选取限流与准比例谐振(proportional ... 详细信息

为了使含有源电力滤波器(active power filter,APF)功能的光伏并网逆变器在指令电流超过逆变器的限值时具有良好的谐波补偿效果,分析了传统比例式限流和指令电流跟踪方法的不足,提出了一种自适应谐波选取限流与准比例谐振(proportional resonant,PR)电流协调控制相结合的并网控制策略。自适应谐波选取限流策略可以在逆变器容量超限时针对性地选取危害大、含量高的谐波分量进行补偿,提高限流措施的有效性;准PR电流协调控制策略可以对指令电流中的各谐波分量进行单独控制,进一步提高谐波补偿的精确性。仿真结果表明,所提控制策略可以提高不同并网场景下的谐波补偿效果,验证了其可行性和有效性。

关键词：光伏并网自适应谐波补偿比例式限流准PR电流协调控制

Cohomology of the Schrdinger Algebra S(1)

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Acta Mathematica Sinica,English Series 2014年第12期30卷 2054-2062页

作者： Yue zhu wu Xiao Qing YUE Lin Sheng zhu Department of Mathematics Changshu Institute of Technology Department of Mathematics Tongji University

We explicitly compute the first and second cohomology groups of the SchrSdinger algebra S（1） with coefficients in the trivial module and the finite-dimensional irreducible modules. We also show that the first and second cohomology groups of S（1） with coefficients in the universal enveloping algebras U（S（1））（under the adjoint action） are infinite dimensional.

关键词： Schrodinger algebra first cohomology groups second cohomology groups

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苯炔的制备和反应实验的改进与再设计

化学教育（中英文） 2024年第8期45卷 43-47页

作者：文巍吴杉石佳乔恪凡郭其祥吴竹莲西南大学化学化工学院重庆400715

苯炔的制备和反应实验同时融合了苯炔和Diels-Alder反应相关知识,是大学有机化学实验教学的重要内容之一。传统的实验方案以邻氨基苯甲酸为原料首先制得取代芳基重氮盐,通过重氮盐的热分解产生苯炔,然后与蒽发生Diels-Alder反应。但邻... 详细信息

苯炔的制备和反应实验同时融合了苯炔和Diels-Alder反应相关知识,是大学有机化学实验教学的重要内容之一。传统的实验方案以邻氨基苯甲酸为原料首先制得取代芳基重氮盐,通过重氮盐的热分解产生苯炔,然后与蒽发生Diels-Alder反应。但邻氨基苯甲酸属于第一类易制毒化学品,为本实验的开展带来不便。同时传统方案还存在诸多不足,如存在潜在的爆炸风险,需要使用到危化品试剂,产品纯化难度大且操作繁琐等。本改进方案通过改变苯炔前体和苯炔捕获试剂克服了原有方案的不足,并且实验原料易得、时长合适、条件温和、反应重复性好,适合本科有机化学实验教学。更为重要的是,通过设计对照实验引入探索性讨论学习内容,有利于学生综合能力的提升和科学思维的培养。

关键词：苯炔 Diels-Alder反应呋喃实验改进