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Effect of surfactant frequently used in soil flushing on oxygen mass transfer in micro-nano-bubble aeration system

Chinese Journal of Chemical Engineering 2024年第3期67卷 174-181页

作者： Mei Bai zhibin liu Zhu liu Chenfei He Zhanhuang Fan Miaoxin Yuan Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety Southeast UniversityNanjing 211189China CECEP DADI(Hangzhou)Environmental Remediation Co. Ltd.Hangzhou 310020China

In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated *** surfactant present in flushing solutions is bound to affect the aeration *** purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MNB)aeration ***,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MNB aeration ***,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MNB *** results showed that,for the twenty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)*** phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant *** addition,with the presence of electric charge,MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant ***,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant ***,the modified Frossling's model predicted the effect of surfactant on kL in MNB aeration system with reasonable accuracy.

关键词： Soil flushing Micro-nano-bubble aeration Bio-surfactant Mass transfer coefficient

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The Static Stability Region of an Integrated Electricity-Gas System Considering Voltage and Gas Pressure

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Engineering 2024年第5期36卷 132-145页

作者： Yunfei Mu zhibin liu Xiangwei Guo Hongjie Jia Kai Hou Xiaodan Yu Bofeng Luo Hairun Li Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China State Grid Tianjin Electric Power Company Tianjin 300201China China Southern Power Grid Digital Grid Research Institute Co. Ltd.Guangzhou 510700China

In an integrated electricity-gas system(IEGS),load fluctuations affect not only the voltage in the power system but also the gas pressure in the natural gas *** static voltage stability region(SVSR)method is a tool for analyzing the overall static voltage stability in a power ***,in an IEGS,the SVSR boundary may be overly optimistic because the gas pressure may collapse before the voltage ***,the SVSR method cannot be directly applied to an *** this paper,the concept of the SVSR is extended to the IEGS-static stability region(SSR)while considering voltage and gas ***,criteria for static gas pressure stability in a natural gas system are proposed,based on the static voltage stability criteria in a power ***,the IEGS-SSR is defined as a set of active power injections that satisfies multi-energy flow(MEF)equations and static voltage and gas pressure stability constraints in the active power injection space of natural gas-fired generator units(NGUs).To determine the IEGSSSR,a continuation MEF(CMEF)method is employed to trace the boundary point in one specific NGU scheduling direction.A multidimensional hyperplane sampling method is also proposed to sample the NGU scheduling directions *** obtained boundary points are further used to form the IEGSSSR in three-dimensional(3D)space via a Delaunay triangulation hypersurface fitting ***,the numerical results of typical case studies are presented to demonstrate that the proposed method can effectively form the IEGS-SSR,providing a tool for IEGS online monitoring and dispatching.

关键词： Integrated electricity-gas system Static stability region Continuation multi-energy flow Multidimensional hyperplane sampling

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Highly efficient electrosynthesis of H_(2)O_(2)in acidic electrolyte on metal-free heteroatoms co-doped carbon nanosheets and simultaneously promoting Fenton process

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Chinese Chemical Letters 2024年第7期35卷 514-518页

作者： Xiaodan Wang Yingnan liu zhibin liu Zhongjian Li Tao Zhang Yi Cheng Lecheng Lei Bin Yang Yang Hou Key Laboratory of Biomass Chemical Engineering of Ministry of Education College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China Institute of Zhejiang University-Quzhou Quzhou 324000China Donghai Laboratory Zhoushan 316000China Ningbo Institute of Materials Technology&Engineering University of Chinese Academy of SciencesNingbo 315200China School of Biological and Chemical Engineering NingboTech UniversityNingbo 315100China Zhejiang Hengyi Petrochemical Research Institute Co. Ltd.Hangzhou 310058China

Recently electrochemical synthesis of H_(2)O_(2)through oxygen reduction reaction(ORR)via 2e^(-)pathway is considered as a green and on-site ***,it still remains a big challenge for fabricating novel metal-free catalysts under acidic solutions,since it suffers from high overpotential due to the intrinsically week*OOH ***,a co-doped carbon nanosheet(O/N–C)catalyst toward regulating O and N content was synthesized for improving the selectivity and activity of H_(2)O_(2)electrosynthesis *** O/N–C exhibits outstanding 2e-ORR performance with low onset potential of 0.4 V(***)and a selectivity of 92.4%in 0.1 mol/L HClO_(4)*** in situ electrochemical impedance spectroscopy(EIS)tests reveals that the N incorporation contributes to the fast ORR *** density functional theory(DFT)calculations demonstrate that the binding strength of*OOH was optimized by the co-doping of oxygen and nitrogen at certain content,and the O/N–C–COOH site exhibits a lower theoretical overpotential for H_(2)O_(2)formation than O–C–COOH ***,the promoted kinetics for typical organic dye degradation in simultaneous electron-Fenton process on O/N–C catalyst was demonstrated particularly for broadening its environmental application.

关键词： Oxygen reduction Metal-free catalyst H_(2)O_(2)electrosynthesis N doping Carbon materials

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Experimental study on the properties of CMTs-incorporated geopolymers prepared at low temperatures

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Journal of Southeast University(English Edition) 2024年第3期40卷 295-303页

作者： Jin Quanbin liu zhibin Lu Liangliang Zhang Yun Luo Tingyi Tang Yasen Jiangsu Key Laboratory of Low Carbon and Sustainable Geotechnical Engineering Southeast UniversityNanjing 211189China Guangxi Beitou Construction and Investment Group Co. Ltd.Nanning 530028China

Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of *** and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of ***,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are *** results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,*** solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,*** a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive *** resource utilization of CMT and FA is realized in a more economical way.

关键词： copper mine tailings geopolymer solid wastes characterization techniques curing methods carbon dioxide emission

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考虑台风影响的海上风电机组部件剩余寿命预测方法

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电力自动化设备 2024年第6期44卷 35-42页

作者：刘璐洁李传文符杨刘智彬黄玲玲上海电力大学海上风电研究院上海200090 上海电力大学电气工程学院上海200090

针对台风天气影响下海上风电机组剩余寿命预测问题,提出了考虑退化状态与台风冲击相依的海上风电机组部件剩余寿命预测方法。基于台风冲击模型及部件状态对部件退化过程的影响分析,构建了考虑退化状态与冲击相依的海上风电机组部件剩余... 详细信息

针对台风天气影响下海上风电机组剩余寿命预测问题,提出了考虑退化状态与台风冲击相依的海上风电机组部件剩余寿命预测方法。基于台风冲击模型及部件状态对部件退化过程的影响分析,构建了考虑退化状态与冲击相依的海上风电机组部件剩余寿命可靠度模型。利用实际监测数据对部件可靠度模型进行修正更新,建立了剩余寿命动态预测模型。采用fmincon函数对离散化处理后的部件可靠度模型进行参数估计,结合运行监测数据修正参数,进而动态预测剩余寿命。以某海上风电机组齿轮箱部件为例进行仿真,验证了所提方法的有效性。

关键词：海上风电机组台风天气部件可靠度模型剩余寿命预测动态预测

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考虑出力相关性的海上风电接入系统固定成本分摊方法

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浙江电力 2024年第3期43卷 38-46页

作者：刘智彬苏本庆国网上海青浦供电公司上海201799 国网山东省电力公司菏泽供电公司山东菏泽274000

在海上风电规模化开发、集群化并网的背景下,如何回收海上风电接入系统的输电成本,公平合理地向各风电场分摊已成为目前海上风电行业亟待解决的问题。针对该问题,提出了一种考虑风电出力相关性的海上风电接入系统固定成本分摊方法。首先... 详细信息

在海上风电规模化开发、集群化并网的背景下,如何回收海上风电接入系统的输电成本,公平合理地向各风电场分摊已成为目前海上风电行业亟待解决的问题。针对该问题,提出了一种考虑风电出力相关性的海上风电接入系统固定成本分摊方法。首先,利用藤Copula函数构建多个海上风电场的出力相关性模型,同时假定系统负荷需求模型服从正态分布,发电机服从0-1概率分布;然后,结合蒙特卡洛抽样和顺流概率潮流追踪法计算各海上风电场接入系统的固定成本分摊费用;最后,通过算例仿真分析,验证了所提方法的合理性和有效性。

关键词：海上风电风电出力相关性固定成本分摊藤Copula 潮流追踪

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双极型LCC-HVDC直流系统作为黑启动电源的启动方法及策略

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中国电力 2024年第4期57卷 139-150页

作者：王清未刘之滨陈炳奇林济铿国家电网有限公司华北分部北京100053 同济大学电子与信息工程学院上海201804

科学合理的黑启动电源及方案是应对电网灾变停电的最有效策略,可加快其系统恢复进程,大幅减少停电损失。双极型换相换流器型高压直流系统(LCC-HVDC)具有调节灵活输电容量大的优势,但其作为黑启动电源存在一定的困难。提出了以双极型LCC-... 详细信息

科学合理的黑启动电源及方案是应对电网灾变停电的最有效策略,可加快其系统恢复进程,大幅减少停电损失。双极型换相换流器型高压直流系统(LCC-HVDC)具有调节灵活输电容量大的优势,但其作为黑启动电源存在一定的困难。提出了以双极型LCC-HVDC为黑启动电源的黑启动方法及完整过程,实现向受端无源网络恢复供电,以加速其恢复进程。首先给出了双极型LCC-HVDC作为黑启动电源时所面临的问题及相应的解决策略;进而给出了双极型LCC-HVDC作为黑启动电源恢复向受端无源网络恢复供电的实现过程。该过程包括2个阶段,第1阶段实现双极型LCC-HVDC的仿融冰模式启动;第2阶段为从仿融冰模式过渡到向受端无源网络恢复供电过程。算例证实了该启动方法的有效性和正确性。该方法使双极型LCC-HVDC具备了黑启动能力,并利用直流系统为受端电网的系统恢复过程提供了电压和频率支撑。

关键词：黑启动电源双极型LCC-HVDC直流系统仿融冰模式电网灾变停电受端无源网络

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Pressure Regulation for Earth Pressure Balance Control on Shield Tunneling Machine by Using Adaptive Robust Control

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 598-606页

作者： XIE Haibo liu zhibin YANG Huayong State Key Laboratory of Fluid Power&Mechatronic Systems Zhejiang University.Hangzhou 310027.China

Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control（ARC） are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve＇s dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.

关键词： shield tunneling machine pressure regulation adaptive robust control

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负性情绪对听障学生幸福感的影响:体育锻炼与休闲活动满意度的双调节作用

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中国特殊教育 2024年第2期 40-47,73页

作者：孙霁令狐荣丹刘志彬班永飞孙沛安顺学院教育科学学院安顺561000 安顺学院特殊儿童发展与融合教育实验室安顺561000 贵阳市盲聋哑学校贵阳550000 清华大学心理学系北京100084

为探讨听力障碍学生负性情绪、体育锻炼、休闲活动满意度对幸福感的影响,采用抑郁焦虑压力量表、牛津幸福感问卷、体育活动等级量表和休闲满意度量表分别对392名听力障碍学生进行问卷调查。结果显示:(1)负性情绪对听力障碍学生幸福感有... 详细信息

为探讨听力障碍学生负性情绪、体育锻炼、休闲活动满意度对幸福感的影响,采用抑郁焦虑压力量表、牛津幸福感问卷、体育活动等级量表和休闲满意度量表分别对392名听力障碍学生进行问卷调查。结果显示:(1)负性情绪对听力障碍学生幸福感有显著的负向预测作用;(2)体育锻炼和休闲活动满意度在听力障碍学生负性情绪和幸福感之间起调节作用。体育锻炼越多,休闲活动满意度越高,听力障碍学生的幸福感越强,其负性情绪对幸福感的负向预测作用越大。研究结果有助于揭示听力障碍学生负性情绪与幸福感关系的内在机制,并提示体育锻炼和休闲活动满意度能够缓冲负性情绪对听力障碍学生心理健康的消极影响,提升他们的幸福感。

关键词：听力障碍学生负性情绪体育锻炼休闲活动满意度幸福感

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Adjoint based state estimation of compressible flow in porous media

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Petroleum 2021年第1期7卷 39-52页

作者： Yanbin Sun zhibin liu Yanjie Hu School of Science Southwest Petroleum UniversityChengdu610500China

In this paper,we study the state estimation of compressible single phase flow in compressible porous *** initial pressure distribution is estimated according to discrete adjoint approach based on the collected well pressure *** first-order Tykhonov regularization method is used to obtain reasonable *** analyzing the optimality condition of estimation problem,the discrete adjoint state equation and discrete adjoint gradient are derived based on the numerical scheme of the continuous equations.A quasi-Newton numerical optimization method related to adjoint gradient is proposed to solve the estimation *** estimation results with different regularization coefficients are compared and analyzed by numerical *** deviation between the estimated pressure obtained without regularization and the real pressure is *** result with smaller deviation and higher smoothness can be obtained through appropriate regularization *** the observation error is large,the observed values generated by the estimated pressure fit well with the real pressure.

关键词： Regularization Discrete adjoint approach State estimation Single phase compressible flow Porous media

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