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Synergy of a hierarchical porous morphology and anionic defects of nanosized Li_(4)Ti_(5)O_(12) toward a high-rate and large-capacity lithium-ion battery

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Journal of Energy Chemistry 2021年第3期30卷 699-711页

作者： Yanan Li Qianlin Chen qiangqiang meng Shulai Lei Fangxiang Song Jingbo Ma School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025GuizhouChina School of Pharmaceutical Sciences Guizhou University of Traditional Chinese MedicineGuiyang 550025GuizhouChina National&Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025GuizhouChina School of Physics and Materials Engineering Hefei Normal UniversityHefei 230601AnhuiChina Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053HubeiChina

Exploring electrode materials with a high volumetric energy density and high rate capability remains of a great challenge for nanosized-Li_(4)Ti_(5)O_(12)(LTO)***,hierarchical porous Ti^(3+)-C-N-Br co-doped LTO(LTOCPB-CC)is synthesized using carboxyl-grafted nanocarbon(CC)and cetylpyridinium bromide(CPB)as combined structure-directing ***^(4+)-O-CPB/Li^(+)-CC is designed as a new molecular chelate,in which CPB and CC promote the uniform mixing of Li^(+)and Ti^(4+)and control the morphology of TiO_(2) and the final *** defects(oxygen vacancies and ion dopants)formed during the annealing process increase the electron/hole concentration and reduce the band gap,both of which enhance the n-type electron modification of ***-prepared LTOCPB-CC has a large specific surface area and high tap density,as well as a high electronic conductivity(2.84×10^(-4) S cm^(-1))and ionic conductivity(3.82×10^(-12)cm^(2) s^(-1)),which are responsible for its excellent rate capability(157.7 mA h g^(-1) at 20 C)and stable long-term cycling performance(0.008% fade per cycle after 1000 cycles at 20 C).

关键词： Lithium titanate Hierarchical morphology Porous Defects Lithium-ion batteries

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双层直线振动筛的筛分性能模拟研究

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辽宁科技大学学报 2024年第2期47卷 146-153页

作者：王鹏王宇孟强强马学东邓祥伟辽宁科技大学机械工程与自动化学院辽宁鞍山114051

为了强化双层直线振动筛对塑料颗粒的筛分性能,采用离散元法建立双层直线振动筛和塑料颗粒模型,仿真研究塑料颗粒在筛分中的运动特性,利用单因素控制变量法和四因素四水平的正交试验法分析振动频率、振动方向角、振幅和筛面倾角对双层... 详细信息

为了强化双层直线振动筛对塑料颗粒的筛分性能,采用离散元法建立双层直线振动筛和塑料颗粒模型,仿真研究塑料颗粒在筛分中的运动特性,利用单因素控制变量法和四因素四水平的正交试验法分析振动频率、振动方向角、振幅和筛面倾角对双层直线振动筛筛分性能的影响。结果表明,塑料颗粒在筛面上可快速达到稳定筛分阶段;两层筛面的透筛分别发生在筛面入料口附近和筛面前中段;振动方向角增加,上层筛面筛分效率稳定在92%,下层筛面筛分效率先减小后增大;振幅增大,两层筛面的筛分效率都减小;振动频率或筛面倾角增加,都会导致上层筛面筛分效率先增大后减小,下层筛面筛分效率下降。采用双层直线振动筛筛分塑料颗粒的最优参数组合为振动频率15 Hz、振动方向角40°、振幅5 mm和筛面倾角4°。研究结果为双层直线振动筛性能提升提供依据。

关键词：双层直线振动筛塑料颗粒离散元法运动特性筛分效率

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Numerical study on the use of soft material walls to enhance seismic performance of an existing tunnel

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Underground Space 2024年第2期15卷 90-112页

作者： qiangqiang Sun menghao Hou Daniel Dias Institute of Geotechnical Engineering College of Civil Engineering and ArchitectureHebei UniversityBaoding 071002China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

Seismic risk is one of the biggest challenges for tunnel safety,and several mitigation techniques have been proposed to enhance the seismic performance of existing *** paper aims to investigate the effectiveness of an innovative approach for reducing the seismic risk of existing tunnels by using soft material walls(SMW)symmetrically installed in the surrounding *** investigation is performed with a two-dimensional numerical model and the effectiveness of SMW in mitigating the seismic-induced lining forces is quantitatively evaluated by reduction *** influences of nonlinear properties of soil,SMW and tunnel lining on the isolation effectiveness are also *** parametric studies show that the computed reduction ratio is strongly affected by the modulus ratio between the SMW and the soil,the wall geometric parameter,and the flexibility *** is more effective for the thick and soft isolation walls that are inserted near a stiff tunnel in the soft *** tunnel seismic response can be reduced by up to 50%for the scenarios ***,the parametric study identifies an optimum normalized depth of SMW and recommends a relation between the maximum isolation effect and the flexibility ***,simple charts are suggested in this work for estimating the isolation effect in specific conditions of the soil and the *** these lines,the results of this work may be used in the seismic retrofitting of an existing tunnel,aiding the preliminary design of the isolation walls.

关键词： Tunnels Earthquakes Seismic analysis Isolation walls Soft material

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Effects of Co-Firing Biomass and Pulverized Coal on NO Reduction in Cement Precalciner

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Journal of Thermal Science 2024年第2期33卷 751-760页

作者： LI Pengpeng REN qiangqiang LYU Qinggang WANG Mingyue School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

With increased awareness of the large-scale CO_(2) emissions from the cement industry,there has been growing focus on greenhouse gas reduction *** all these strategies,fuel substitution using biomass fuel is extensively used to achieve CO_(2) zero-emission in cement *** to the avoidable high-temperature-generated thermal nitrogen oxides during cement production,research on the impact of biomass application on nitrogen oxide emissions shall be carried *** types of biomass fuel and bituminous coal were used to investigate the NO reduction characteristics under different O_(2) concentrations on experimental *** was found that the change in oxygen concentration from 9% to 1% increased the reaction time in the reactor from 555 s to 1425 s,which means the increase in oxygen concentration can lead to shorter reaction time,and correspondingly,the existing time of nitric oxide in the flue gas is also shortened,but the peak value of nitric oxide rises,during the process of O_(2) concentration changing from 1% to 9%,the peak NO concentration in the flue gas increased from 5.4×10^(-5) to 1.05×10^(-4).An increase in O_(2) concentration greatly reduces the total reduction of NO and the minimum change in NO *** peak NO concentration during the combustion process of corn stalk is 4.56×10^(-4),which is approximately 7 times higher than that of coal,and it is caused by the high amount of N in corn *** addition of raw meal has an inhibitory effect on the reduction of NO:after adding raw meal,the effective reduction time of NO by fuel decreased by about 20%,but adding raw meal raises CO_(2) concentration of fuel gas in the early stage of reaction.

关键词： cement precalciner biomass fuel coal NO reduction co-firing

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Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG Wenyu LI Wei LU Yu REN qiangqiang LYU Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel *** gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of ***,there is an urgent need to investigate methods for its *** combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual *** order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

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Evolution Mechanism of Carbon Covalent Bond during Coal Activation Using Mixed Atmosphere of H_(2)O and CO_(2)

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Journal of Thermal Science 2024年第5期33卷 1961-1973页

作者： WANG Mingyue ZHANG Siyuan HAN Shaobo ZHANG Chi REN qiangqiang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Coal Conversion Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China

Adequate destruction of the aromatic structure in coal is key to further reducing the emission of *** this research,activation reactions of Shenmu coal powder were carried out in a vertical tube *** study investigated the evolution mechanism of carbon covalent bonds during the activation process by altering the ratio of H_(2)O to CO_(2)in the activation *** theoretical validation was conducted through density functional *** two gas molecules follow different pathways to increase the reactivity of ***_(2)mainly participates in the cross-linking reaction by intensifying branching,while H_(2)O and char have lower adsorption energy barriers and are more likely to generate oxygen-containing functional *** molecules partially compete for active sites in a mixed gas atmosphere,but there is a synergism between the two *** synergism can be attributed to two *** inclusion of H_(2)O mitigates the generation of five-membered rings to a limited extent,while concurrently enhances the development of oxygen-containing functional *** oxygen-containing functional groups can effectively diminish the adsorption energy barrier associated with the interaction between gas molecules and char,consequently leading to a reduction in the energy demand for subsequent bond cleavage.

关键词： activation reaction carbon structure char CO_(2)/H_(2)O atmosphere density functional theory

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Steady-state Voltage Security-constrained Optimal Frequency Control for Weak HVDC Sending-end AC Power Systems

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 658-669页

作者： qiangqiang Wang Liangzhong Yao Jian Xu Yuping Zheng Wei Li Wei Wang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Hubei Engineering and Technology Research Center for AC/DC Intelligent Distribution Network(Wuhan University) Wuhan 430072China State Key Laboratory of Smart Grid Protection and Control NARI Group Corporation(State Grid Electric Power Research Institute)Nanjing 211106China

Due to the fact that a high share of renewable energy sources(RESs)are connected to high-voltage direct current(HVDC)sending-end AC power systems,the voltage and frequency regulation capabilities of HVDC sending-end AC power systems have *** has resulted in potential system operating problems such as overvoltage and overfrequency,which occur simultaneously when block faults exist in the HVDC *** this study,a steady-state voltage security-constrained optimal frequency control method for weak HVDC sending-end AC power systems is *** integrated virtual inertia control of RESs is employed for system frequency *** dynamic reactive power compensation devices are utilized to control the voltage of all nodes meet voltage security ***,an optimization model that simultaneously considers the frequency and steady-state voltage security constraints for weak HVDC sending-end AC power systems is *** optimal control scheme with the minimum total cost of generation tripping and additional dynamic reactive power compensation required is obtained through the optimization *** are conducted on a modified IEEE 9-bus test system and practical Qing-Yu line commutated converter based HVDC(LCC-HVDC)sending-end AC power system to verify the effectiveness of the proposed method.

关键词： Renewable energy source(RES) high-voltage direct current(HVDC) AC power system optimal frequency control steady-state voltage security dynamic reactive power compensation

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Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

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Food Science and Human Wellness 2024年第3期13卷 1135-1151页

作者： Enning Zhou qiangqiang Li Dan Zhu Gang Chen Liming Wu Institute of Apicultural Research Chinese Academy of Agricultural SciencesBeijing 100093China Department of Food Science University of OtagoDunedin 9016New Zealand School of Food and Health Beijing Technology and Business UniversityBeijing 100048China

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding *** the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce *** here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic *** techniques for characterizing changes in these properties of food allergens are *** processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new ***,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food *** provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

关键词： Food allergens Protein structural characterization Immunogenicity evaluation Food processing modification

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Electronic and optical properties of TiO2 nanotubes and arrays: A first-principles study

Electronic and optical properties of TiO2 nanotubes and arra...

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中国化学会第十二届全国量子化学会议

作者： qiangqiang meng Zhaoyong Guan Jing Huang Qunxiang Li Jinlong Yang Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China School of Materials and Chemical Engineering Anhui University of ArchitectureHefeiAnhui 230022China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China

Recently,the synthesis,properties,modifications,and applications of Ti O2 nanomaterials have attracted much research ***,based on extensive density functional theory calculations,we explore the stability,electronic structures and optical absorption properties of single-walled Ti O2 nanotubes（SWTONTs）and Ti O2 nanotube arrays（TONTAs）,which is constructed by anatase Ti O2（101）monolayer and bilayer,*** obtain the stable Dnd（n=3-5）and S2n（-n,n）（n=3-9）SWTONTs,and find that the SWTONTs energetically prefer the S2n *** with S2n（-n,n）SWTONTs,the calculated Young’s modulus of Dnd（-n,n）SWTONTs are more stiff due to their relative large strain *** band gaps of hexagonal TONTAs are not sensitive to their apertures,which are less than that of Ti O2 *** narrowing band gaps of TONTAs originate from the edge states mainly contributed by the Ti and O atoms at the core *** calculated optical absorptions of both SWTONTs and TONTAs display anisotropic *** results clearly reveal that the electronic and optical properties of Ti O2 nanostructures are strongly associated with their symmetry,dimension and morphology,which provide useful insights into the understanding of the related experimental observations.

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基于梯度加权的红外与可见光图像融合方法

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红外与激光工程 2014年第8期43卷 2772-2779页

作者：杨桄童涛孟强强孙嘉成空军航空大学吉林长春130022

针对可见光和红外图像融合问题,提出一种有效的融合方法。首先,将多尺度分解后的高频系数分为高低两层,并针对各层系数的特点,分别采用基于像素和基于区域特征加权的融合算法合成得到融合图像的高频系数;为了进一步提升融合图像的整体... 详细信息

针对可见光和红外图像融合问题,提出一种有效的融合方法。首先,将多尺度分解后的高频系数分为高低两层,并针对各层系数的特点,分别采用基于像素和基于区域特征加权的融合算法合成得到融合图像的高频系数;为了进一步提升融合图像的整体对比度,提高目标的指示能力,提出通过区域平均梯度特征自适应加权的方法得到融合图像的低频系数;最后,对融合的低频和高频系数进行多尺度逆变换得到融合图像。通过主观观察以及客观指标对比证明,该方法的融合性能优于经典的融合方法。

关键词： NSCT变换相关信号强度比平均梯度图像融合

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