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Efficient Pt/KFI zeolite catalysts for the selective catalytic reduction of NOxby hydrogen

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Journal of Environmental Sciences 2024年第4期138卷 102-111页

作者： Ligang Zhang Yulong Shan Zidi Yan zhongqi Liu Yunbo Yu Hong he School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Aiming at purification of NO_(x)from hydrogen internal combustion engines(HICEs),the hydrogen selective catalytic reduction(H_(2)-SCR)reaction was investigated over a series of Pt/KFI zeolite catalysts.H_(2)can readily reduce NO_(x)to N_(2)and N_(2)O while O_(2)inhibited the deNO_(x)efficiency by consuming the reductant H_(2).The Pt/KFI zeolite catalysts with Pt loading below 0.1wt.% are optimized H_(2)-SCR catalysts due to its suitable operation temperature window since high Pt loading favors the H_(2)-O_(2)reaction which lead to the insufficient of reactants.Compared to metal Pt^(0)species,Pt^(δ+)species showed lower activation energy of H_(2)-SCR reaction and thought to be as reasonable active sites.Further,Eley-Rideal(E-R)reaction mechanism was proposed as evidenced by the reaction orders in kinetic studies.Last,the optimized reactor was designed with hybrid Pt/KFI catalysts with various Pt loading which achieve a high NO_(x)conversion in a wide temperature range.

关键词： Pt/KFI zeolite Pt loading H_(2)-SCR Reaction conditions Kinetics studies

Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1615-1636页

作者： Wendal Victor Yue Siyuan Wu Manchao he Yafei Qiao zhongqi Quentin Yue Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai200092China Department of Civil Engineering Faculty of EngineeringThe University of Hong KongPokfulam RoadHong KongChina State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai200092China

Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)hammer.Seven transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time series.The mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time series.These processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and rod-untightening.The drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six drillholes.Each curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering grades.The effect from fluctuation of the applied pressures is evaluated quantitatively.Detailed analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time.

关键词： Drilling process monitoring(DPM) Down-the-hole(DTH)hammer Percussive-rotary drilling Weathering granitic rocks

Study on concentration distribution and detonation characteristics for non-axisymmetric fuel dispersal

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Defence Technology（防务技术） 2024年第1期31卷 484-495页

作者： Linghui Zeng zhongqi Wang Xing Chen Jianping Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China College of Environment and Chemical Engineering Sichuan University of Science&EngineeringZigong643000China

The study of non-axisymmetric fuel dispersal and detonation can provide reference for the prevention of industrial cloud explosion accidents and the design of fuel air explosive(FAE).The concentration and detonation fields of 85 kg cylindrical and fan-shaped fuel are investigated by experiments and numerical simulations.A dynamic model of the whole process for fuel dispersal and detonation is built.The concentration distribution of fuel is used as the initial condition to calculate the detonation stage,thus solving the initial value problem of detonation field.The phase and component changes of fuel cloud at different locations are compared.The fuel cloud is divided into directions of 0°,90°,135°and 180°.The results show that the maximum cloud radius is 20.94 m in 135°and the minimum is 12.04 m in 0°.The diameter of the detonation fireball is 53.6 m,and the peak temperature is 3455 K.The highest peak overpressure is 3.44 MPa in 0°and the lowest is 2.97 MPa in 135°.The proportion of liquid phase in 0°is22.90%,and the fuel loss is 11.8% and 9% higher than that in 135°and cylindrical charge,respectively.The stable propagation distance of blast wave in 135°is 42.50% longer than 0°and 28.37% longer than cylindrical charge.

关键词： Fuel dispersal Concentration distribution Detonation characteristic Fuel loss Numerical simulation

Model-free adaptive robust control method for high-speed trains

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Transportation Safety and Environment 2024年第1期6卷 93-102页

作者： zhongqi Li Liang Zhou Hui Yang Yue Yan School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang 330013JiangxiChina State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013JiangxiChina

Aiming at the robustness issue in high-speed trains(HSTs)operation control,this article proposes a model-free adaptive control(MFAC)scheme to suppress disturbance.Firstly,the dynamic linearization data model of train system under the action of measurement disturbance is given,and the Kalman filter(KF)based on this model is derived under the minimum variance estimation criterion.Then,according to the KF,an anti-interference MFAC scheme is designed.This scheme only needs the input and output data of the controlled system to realize the MFAC of the train under strong disturbance.Finally,the simulation experiment of CRH380A HSTs is carried out and compared with the traditional MFAC and the MFAC with attenuation factor.The proposed control algorithm can effectively suppress the measurement disturbance,and obtain smaller tracking error and larger signal to noise ratio with better applicability.

关键词： automatic train operation(ATO) model-free adaptive control(MFAC) disturbance suppression minimum variance estimation Kalman filtering(KF) partial format data model

Extended wet sieving method for determination of complete particle size distribution of general soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 242-257页

作者： Shengnan Ma Yi Song Jiawei Liu Xingyu Kang zhongqi Quentin Yue Department of Civil Engineering The University of Hong KongHong KongChina

The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.

关键词： Particle size distribution(PSD) General soil Silt Clay Wet sieving Physical and chemical properties

Highly selective extraction of aromatics from aliphatics by using metal chloride-based ionic liquids

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Chinese Journal of Chemical Engineering 2024年第1期65卷 222-229页

作者： Hui Yu Xiaojia Wu Chuanqi Geng Xinyu Li Chencan Du Zhiyong Zhou zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The separation of aromatics from aliphatics is essential for achieving maximum exploitation of oil resources in the petrochemical industry.In this study,a series of metal chloride-based ionic liquids were prepared and their performances in the separation of 1,2,3,4-tetrahydronaphthalene(tetralin)/dodecane and tetralin/decalin systems were studied.Among these ionic liquids,1-ethyl-3-methylimidazolium tetrachloroferrate([EMIM][FeCl_(4)])with the highest selectivity was used as the extractant.Density functional theory calculations showed that[EMIM][FeCl_(4)]interacted more strongly with tetralin than with dodecane and decalin.Energy decomposition analysis of[EMIM][FeCl_(4)]-tetralin indicated that electrostatics and dispersion played essential roles,and induction cannot be neglected.The van der Waals forces was a main effect in[EMIM][FeCl_(4)]-tetralin by independent gradient model analysis.The tetralin distribution coefficient and selectivity were 0.8 and 110,respectively,with 10%(mol)tetralin in the initial tetralin/dodecane system,and 0.67 and 19.5,respectively,with 10%(mol)tetralin in the initial tetralin/decalin system.The selectivity increased with decreasing alkyl chain length of the extractant.The influence of the extraction temperature,extractant dosage,and initial concentrations of the system components on the separation performance were studied.Recycling experiments showed that the regenerated[EMIM][FeCl_(4)]could be used repeatedly.

关键词： Ionic liquid Aromatic hydrocarbon Aliphatic hydrocarbon Extraction

A 3D-printed microhemispherical shell resonator with electrostatic tuning for a Coriolis vibratory gyroscope

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Microsystems & Nanoengineering 2024年第2期10卷 25-35页

作者： Baoyin Hou Ye Zhu Chaofan he Weidong Wang Zhi Ding Wen he Yong he Lufeng Che College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou310027China Center for Microelectronics Shaoxing InstituteZhejiang UniversityShaoxing312035China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China School of Mechanical Engineering Zhejiang UniversityHangzhou310058China

The emergence of microhemispherical resonant gyroscopes,which integrate the advantages of exceptional stability and long lifetime with miniaturization,has afforded new possibilities for the development of whole-angle gyroscopes.However,existing methods used for manufacturing microhemispherical resonant gyroscopes based on MEMS technology face the primary drawback of intricate and costly processing.here,we report the design,fabrication,and characterization of the first 3D-printable microhemispherical shell resonator for a Coriolis vibrating gyroscope.We remarkably achieve fabrication in just two steps bypassing the dozen or so steps required in traditional micromachining.By utilizing the intricate shaping capability and ultrahigh precision offered by projection microstereolithography,we fabricate 3D high-aspect-ratio resonant structures and controllable capacitive air gaps,both of which are extremely difficult to obtain via MEMS technology.In addition,the resonance frequency of the fabricated resonators can be tuned by electrostatic forces,and the fabricated resonators exhibit a higher quality factor in air than do typical MEMS microhemispherical resonators.This work demonstrates the feasibility of rapidly batch-manufacturing microhemispherical shell resonators,paving the way for the development of microhemispherical resonator gyroscopes for portable inertial navigation.Moreover,this particular design concept could be further applied to increase uptake of resonator tools in the MEMS community.

关键词： resonator tuning electrostatic

Chemotherapy induces breast cancer stem cell enrichment through repression of glutathione S-transferase Mu

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Genes & Diseases 2024年第2期11卷 528-531页

作者： Jing he Yiran Yu Yilin he Jie he Guangyu Ji Haiquan Lu The Second Hospital and Advanced Medical Research Institute Cheeloo College of MedicineShandong UniversityJinanShandong 250012China Department of Nursing The First Affiliated Hospital of Shandong First Medical UniversityJinanShandong 250014China School of Medicine Xinjiang Medical UniversityUrumqiXinjiang 830054China School of Medicine Binzhou Medical UniversityYantaiShandong 264003China Oncology Department Jinan Zhangqiu District People's HospitalJinanShandong 250200China Key Laboratory for Experimental Teratology of the Ministry of Education Cheeloo College of MedicineShandong UniversityJinanShandong 250012China Center for Reproductive Medicine Shandong UniversityJinanShandong 250012China

Triple-negative breast cancer(TNBC)has aggressive characteristics as exemplified by the high risk of recurrence,metastasis,and patient mortality.1 Cytotoxic chemotherapy may reduce tumor burden initially,but leave behind chemo-resistant breast cancer stem cells(BCSCs)that lead to tumor recurrence and metastasis.2 Chemotherapy induces BCsC enrichment through the activation of glutathione biosynthesis pathways,which increases intracellular glutathione levels and specifies the BCSC phenotype through complicated downstream signaling pathways.3 Glutathione S-transferases(GSTs),a superfamily(which contains seven cytosolic classes:Alpha,Kappa,Mu,Omega,Pi,Theta,and Zeta,and one microsomal class MGSTs)of phase Il enzymes that catalyze the conjugation of glutathione with electrophilic compounds,play a critical role in detoxification and chemotherapy resistance of cancer cells.However,the role of GSTs in the regulation of BCSCs is largely elusive.

关键词： chemotherapy breast metastasis

Coupled Numerical Simulation of Electromagnetic and Flow Fields in a Magnetohydrodynamic Induction Pump

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Fluid Dynamics & Materials Processing 2024年第4期20卷 889-899页

作者： he Wang Ying he College of Transportation Ludong UniversityYantai264025China College of Intelligent Manufacturing City College of HuizhouHuizhou516025China

Magnetohydrodynamic(MHD)induction pumps are contactless pumps able to withstand harsh environments.The rate of fluid flow through the pump directly affects the efficiency and stability of the device.To explore the influence of induction pump settings on the related delivery speed,in this study,a numerical model for coupled electromagnetic and flow field effects is introduced and used to simulate liquid metal lithium flow in the induction pump.The effects of current intensity,frequency,coil turns and coil winding size on the velocity of the working fluid are analyzed.It is shown that the first three parameters have a significant impact,while changes in the coil turns have a negligible influence.The maximum increase in working fluid velocity within the pump for the parameter combination investigated in this paper is approximately 618%.As the frequency is increased from 20 to 60 Hz,the maximum increase in the mean flow rate of the working fluid is approximately 241%.These research findings are intended to support the design and optimization of these devices.

关键词： Magnetic fluid multi-physical field coupling induction pump numerical simulation liquid metal conveying