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Optimization of Hydrocracking Process for Enhanced BTX Production from Coal Tar-Derived Hydrorefined Products

China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 139-151页

作者： Wu Hao Wei Hongyuan School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China SINOPEC research Institute of Petroleum Processing Co. Ltd.Beijing 100083China

Hydroconversion of coal tar to produce aromatic hydrocarbons(BTX)represents a crucial strategy for the highvalue hierarchical utilization of *** study focused on the hydrocracking of hydrorefined products derived from coal tar to enhance the production of benzene,toluene,and xylene(BTX).Various reaction conditions,including reaction temperature,hydrogen pressure,space velocity,and hydrogen-to-oil volume ratio,were systematically explored to optimize BTX yields while also considering the process’s economic *** results indicate that increasing the reaction temperature from 360℃ to 390℃ significantly favors the production of BTX,with yields increasing from 21.42%to 41.14%.Similarly,an increase in hydrogen pressure from 4 MPa to 6 MPa boosts BTX production,with yields rising from 36.31%to 41.14%.Reducing the space velocity from 2 h^(-1) to 0.5 h^(-1) also favors the BTX production process,with yields increasing from 37.96%to 45.13%.Furthermore,raising the hydrogen-to-oil volume ratio from 750 to 1500 improves BTX yields from 41.61%to 45.44%.Through economic analysis,the optimal conditions for BTX production were identified as a reaction temperature of 390℃,hydrogen pressure of 5-6 MPa,space velocity of 1 h^(-1),and hydrogen-to-oil volume ratio of 1000,achieving a BTX yield of 43.73%.This investigation highlights the importance of a holistic evaluation of hydrocracking conditions to optimize BTX ***,the findings offer valuable insights for the design and operation of industrial hydrocracking processes aimed at efficiently converting coal tar-derived hydrorefined feedstock into BTX.

关键词： coal tar hydrocracking BTX process optimization economic assessment

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Evaluation of the Oxidation Reactivity and Behavior of Exhaust Soot Particles from Diesel Engines with Different Emission Levels

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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 72-80页

作者： Wang Yajun Lin Lei Xing Jianqiang LüXu Yang He Song Haiqing SINOPEC research Institute of Petroleum Processing Co. Ltd.Beijing 100083China State Key Laboratory of Engines Tianjin UniversityTianjin 300072China

The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel *** samples from two diesel engines(1K,CY4102)with different emission levels were collected by a thermophoretic system and a quartz *** oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman *** results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic C—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel *** on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation *** oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal *** oxidation mode of soot particles from the 1K engine was significantly higher than that of CY4102.

关键词： diesel engine soot particles oxidation reactivity oxidation behavior

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Superconducting single-photon detector with a speed of 5 GHz and a photon number resolution of 61

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Photonics research 2024年第6期12卷 1328-1333页

作者： TIANZHU ZHANG JIA HUANG XINGYU ZHANG CHAOMENG DING HUIQIN YU YOU XIAO CHAOLIN LV XIAOYU LIU ZHEN WANG LIXING YOU XIAOMING XIE HAO LI Shanghai Key Laboratory of Superconductor integrated Circuit Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Photon Technology(Zhejiang)Co. Ltd.Jiaxing 314100China

Rapid detection and discrimination of single photons are pivotal in various applications,such as deep-space laser communication,high-rate quantum key distribution,and optical quantum ***,conventional single-photon detectors(SPDs),including semiconducting and recently developed superconducting detectors,have limited detection speed and photon number resolution(PNR),which pose significant challenges in practical *** this paper,we present an efficient,fast SPD with good PNR,which has 64 paralleled,sandwiched superconducting nanowires fabricated on a distributed Bragg *** detector is operated in a compact Gifford–McMahon cryocooler that supports 64 electrical channels and has a minimum working temperature of 2.3 *** combined detector system shows a functional nanowire yield of 61/64,a system detection efficiency of 90%at 1550 nm,and a maximum count rate of 5.2 ***,it has a maximum PNR of 61,corresponding to the operating *** SPD signifies a substantial improvement in quantum detector technology,with potential applications in deep-space laser communication,high-speed quantum communication,and fundamental quantum optics experiments.

关键词： communication photon quantum

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Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

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International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao Liang Dong Wang Guanghe Li Guangyu Sun Mingyu Yu Dong Xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability ***,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical ***,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope *** the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding *** integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is ***,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is *** analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear *** spatial form equation of the sliding mass comprises an ellipsoid and weak plane *** analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite ***,the3D stability coefficient of the composite slope exhibits an exponential co

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

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Fe-N-C heterogeneous Fenton-like catalyst for the degradation of tetracycline:Fe-N coordination and mechanism studies

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Chinese Chemical Letters 2024年第9期35卷 309-314页

作者： Weichen Zhu Wei Zuo Pu Wang Wei Zhan Jun Zhang Lipin Li Yu Tian Hong Qi Rui Huang State Key Laboratory of Urban Water Resource and Environment(SKLUWRE) School of EnvironmentHarbin Institute of TechnologyHarbin 150090China Guangdong Yuehai Water Investment Co. Ltd.Shenzhen 518021China National Engineering research Center of Urban Water Resources Co. Ltd.Harbin Institute of TechnologyHarbin 150090China

Fe-N-C materials have received increasing attention,due to its distinctive catalytic ***,the Fe-N coordination number dependence of catalytic ability and mechanism for H_(2)O_(2)activation remain ***,a series of Fe-N-C heterogeneous Fenton-like catalysts with different Fe-N coordination number were prepared for tetracycline *** results demonstrated that samples with Fe-N4 structure exhibited high *** excellent performance was mainly ascribed to the high adsorption capacity and the formation of superoxide radicals(•O_(2)^(−))catalyzed by Fe linked to pyridinic *** intermediates and degradation pathways of tetracycline degradation by Fe-N-C/H_(2)O_(2)system were analyzed by liquid chromatography coupled to tandem mass spectrometry(LC-MS/MS).Furthermore,we applied our Fe-N-C catalysts to treat simulated pharmaceutical wastewater with high tetracycline degradation capacity despite high concentrations of organic matter such as oxalic acid and various ionic *** work reveals the dependence of the activation H_(2)O_(2)on the Fe-N coordination environment and the degradation mechanism of these *** provides insights into the prospects for tuning the catalyst in practical applications.

关键词： H_(2)O_(2)activation Advanced oxidation process Superoxide radicals Degradation pathways EXAFS

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High-frequency Resonance Analysis and Impedance Reshaping Control of MMC-HVDC System Based on Frequency Coupling Impedance Model

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 646-657页

作者： Juanjuan Wang Wei Chen Yuekun Liu Chuang Fu Yunming Ye Junjie Feng School of Electric Power South China University of TechnologyGuangzhouChina Guangdong Power Grid Co. Ltd.GuangzhouChina Electric Power research Institute China Southern Power GridGuangzhouChina

In recent years, high-frequency resonance (HFR) events occurred in several modular multilevel converter based high-voltage direct current (MMC-HVDC) projects. The time delay of an MMC-HVDC system is the critical factor that induces HFR. The frequency coupling affects the impedance characteristics of an MMC and further deteriorates system stability. Therefore, in this paper, a multi-input multi-output admittance model of an MMC-HVDC system is developed to analyze its frequency characteristics. The effects of current loop, power loop, phase-locked loop, and operating point on the MMC frequency coupling degree are analyzed in detail. Meanwhile, to further suppress HFR in the MMC-HVDC system, an enhanced impedance reshaping control strategy based on the equivalent single-input single-output impedance model is proposed. Finally, the accuracy of the enhanced impedance model and the effectiveness of the impedance reshaping control are verified by electromagnetic transient simulations in PSCAD.

关键词： Modular multilevel converter based high-voltage direct current(MMC-HVDC) high-frequency resonance frequency coupling impedance model impedance reshaping control

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Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel research International 2024年第7期31卷 1811-1823页

作者： Zhong-lin Wang Zhi-hua Gong Quan Li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

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Command filtered integrated estimation guidance and control for strapdown missiles with circular field of view

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Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei Wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China China research and Development Academy of Machinery Equipment Beijing 100089China Northwest Industries Group CO. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown *** threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV *** boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular ***,the nonlinear adaptive controller is designed to estimate the changing aerodynamic *** generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking ***,the command filters are used to solve the"differential expansion"problem during the backstepping *** Lyapunov theory is used to prove the stability of the overall closed-loop IEGC ***,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： integrated estimation guidance and control Circular field-of-view Time-varying integral barrier Lyapunov function Command filtered backstepping control Nonlinear adaptive control Extended state observer

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Preparation of high-purity fluorite and nanoscale calcium carbonate from low-grade fluorite

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1198-1207页

作者： Qianqian Lu Haisheng Han Wenjuan Sun Xingfei Zhang Weiwei Wang Bilan Zhang Wensheng Chen Qin Zou School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Hunan Nonferrous Chenzhou Fluoride Chemical Co. Ltd.Chenzhou 423000China State Key Laboratory of Baiyunobo Rare Earth Resource researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030China Hunan Shizhuyuan Nonferrous Metal Co. Ltd.Chenzhou 423000China

Flotation separation of calcite from fluorite is a challenge on low-grade fluorite flotation that limits the recovery and purity of fluorite concentrate.A new acid leaching–flotation process for fluorite is proposed in this *** innovative process raised the fluor-ite’s grade to 97.26wt%while producing nanoscale calcium carbonate from its leachate,which contained plenty of calcium *** the production of nanoscale calcium carbonate,the impacts of concentration,temperature,and titration rate were *** modifying the process conditions and utilizing crystal conditioning agents,calcite-type and amorphous calcium carbonates with corresponding particle sizes of 1.823 and 1.511μm were *** influence of the impurity ions Mn^(2+),Mg^(2+),and Fe^(3+)was demonstrated to reduce the particle size of nanoscale calcium carbonate and make crystal shape easier to manage in the fluorite leach solution system compared with the calcium chloride *** combination of the acid leaching–flotation process and the nanoscale calcium carbonate preparation method improved the grade of fluorite while recovering calcite resources,thus presenting a novel idea for the effective and clean usage of low-quality fluorite resources with embedded microfine particles.

关键词： fluorite calcite nanoscale calcium carbonate waste recovery

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Regression Method for Rail Fastener Tightness Based on Center-Line Projection Distance Feature and Neural Network

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China China Construction Industrial&Energy Engineering Group Co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track ***,routine maintenance and inspection of fasteners are important to ensure the safe operation of track ***,assessment methods for fastener tightness include manual observation,acoustic wave detection,and image *** are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection *** at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural ***,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm *** component analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic *** point is projected onto the upper surface of the bolt to calculate the projection ***,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is ***,by setting up a fastener detection scene in the track experimental base,collecting data,and completing the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect compared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

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