The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R...
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The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.
In the rapidly evolving urban landscape,outdoor parking lots have become an indispensable part of the city’s transportation *** growth of parking lots has raised the likelihood of spontaneous vehicle combus-tion,a si...
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In the rapidly evolving urban landscape,outdoor parking lots have become an indispensable part of the city’s transportation *** growth of parking lots has raised the likelihood of spontaneous vehicle combus-tion,a significant safety hazard,making smoke detection an essential preventative ***,the complex environment of outdoor parking lots presents additional challenges for smoke detection,which necessitates the development of more advanced and reliable smoke detection *** paper addresses this concern and presents a novel smoke detection technique designed for the demanding environment of outdoor parking ***,we develop a novel dataset to fill the gap,as there is a lack of publicly available *** dataset encompasses a wide range of smoke and fire scenarios,enhanced with data augmentation to ensure robustness against diverse outdoor ***,we utilize an optimized YOLOv5s model,integrated with the Squeeze-and-Excitation Network(SENet)attention mechanism,to significantly improve detection accuracy while maintaining real-time processing ***,this paper implements an outdoor smoke detection system that is capable of accurately localizing and alerting in real time,enhancing the effectiveness and reliability of emergency *** show that the system has a high accuracy in terms of detecting smoke incidents in outdoor scenarios.
After the ultralow emission transformation of coal-fired power plants,cement production became China’s leading industrial emission source of nitrogen *** gas dust contents at the outlet of cement kiln preheaters were...
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After the ultralow emission transformation of coal-fired power plants,cement production became China’s leading industrial emission source of nitrogen *** gas dust contents at the outlet of cement kiln preheaters were as high as 80-100 g/m^(3),and the calcium oxide content in the dust exceeded 60%.Commercial V_(2)O_(5)(-WO_(3))/TiO_(2) catalysts suitable for coal-fired flue gas suffer from alkaline earth metal Ca poisoning of cement kiln flue *** studies have also identified the poisoning of cement kiln selective catalytic reaction(SCR)catalysts by the heavy metals lead and *** of the poisoning process is the primary basis for analyzing the catalytic *** review summarizes and analyzes the SCR catalytic mechanism and chronicles the research progress concerning this poisoning *** on the catalytic and toxification mechanisms,it can be inferred that improving the anti-poisoning performance of a catalyst enhances its acidity,surface redox performance-active catalytic sites,and shell layer *** data provide support in guiding engineering practice and reducing operating costs of SCR ***,future research directions for SCR denitrification catalysts in the cement industry are *** study provides critical support for the development and optimization of poisoning-resistant SCR denitrification catalysts.
Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell *** this work,Pt catalysts supported on CeO_(2)and Tb...
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Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell *** this work,Pt catalysts supported on CeO_(2)and Tb-doped CeO_(2)were prepared by a precipitation *** physical structure and chemical properties of the as-prepared catalysts were characterized by powder X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Raman spectroscopy,H_(2)temperature programmed reduction,and X-ray photoelectron *** results show that Tb-doped CeO_(2)supported Pt possesses abundant surface oxygen vacancies,good inhibition of ceria sintering,and strong metal-support interaction compared with CeO_(2)supported *** catalytic performance of hydrogen production via steam reforming of long-chain hydrocarbon fuels(n-dodecane)was *** with 2Pt/CeO_(2),2Pt/Ce_(0.9)Tb_(0.1)O_(2),and 2Pt/Ce_(0.5)Tb_(0.5)O_(2),the 2Pt/Ce_(0.7)Tb_(0.3)O_(2)has higher activity and stability for hydrogen production,on which the conversion of n-dodecane was maintained at about 53.2%after 600 min reaction under 700℃at liquid space velocity of 9 ml·g^(-1)·h^(-1).2Pt/CeO_(2)rapidly deactivated,the conversion of n-dodecane was reduced to only 41.6%after 600 min.
M-N-C(M=Fe,Co,Ni,etc.) catalyst owns high catalytic activity in the oxygen catalytic reaction which is the most likely to replace the Pt-based *** it is still a challenge to further increase the active site *** articl...
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M-N-C(M=Fe,Co,Ni,etc.) catalyst owns high catalytic activity in the oxygen catalytic reaction which is the most likely to replace the Pt-based *** it is still a challenge to further increase the active site *** article constructs the high-efficiency FeMn-N/S-C-1000 catalyst to realize ORR/OER bifunctional catalysis by hetero-atom,bimetal(Fe,Mn) doped simultaneously *** evaluated it as bi-functional electro-catalysts,FeMn-N/S-C-1000 exhibits excellent catalytic activity(E_(1/2)=0.924 V,E_(j=10)=1.617 V) in alkaline media,outperforms conventional Pt/C,RuO_(2) and most non-precious-metal catalysts reported recently,Such outstanding performance is owing to N,S co-coordinated with metal to form multi-types of single atom,dual atom active sites to carry out ***,nitrite poison test provides the proof that the active sites of FeMn-N/S-C are more than that of single-atom catalysts to promote catalytic reactions *** better understand the local structure of Fe and Mn active sites,XAS and DFT were employed to reveal that FeMn-N_5/S-C site plays the key role during ***,the FeMn-N/S-C-1000 based low-temperature rechargeable flexible Zn-air also exhibits superior discharge performance and extraordinary durability at-40℃.This work will provide a new idea to design diatomic catalysts applied in low-temperature rechargeable batteries.
Electrostatic capacitors are the most widely used components in modern electrical and electronic systems ranging from integrated circuits, electrical energy storage and pulsed power *** are the preferred dielectrics f...
Electrostatic capacitors are the most widely used components in modern electrical and electronic systems ranging from integrated circuits, electrical energy storage and pulsed power *** are the preferred dielectrics for electrostatic capacitors owing to their unique self-healing ability, high breakdown strength and ease of processing[1,2]. However, as the operating temperature increases, dielectric polymers exhibit substantially increased conduction loss,
Dual-ion batteries(DIBs)have attracted great attention due to their affordable prices,environmentalfriendliness,and high operating ***,the conventional graphite anode in DIBs has draw-backs such as unsatisfactory capa...
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Dual-ion batteries(DIBs)have attracted great attention due to their affordable prices,environmentalfriendliness,and high operating ***,the conventional graphite anode in DIBs has draw-backs such as unsatisfactory capacity and worrying ***_(2)is considered to be a competitive anodematerial that exhibits large capacity due to its unique layered structure for cation insertion/***,the sluggish reaction kinetics of MoS_(2)does not match the cathode side,which makes theconstructed full DIBs show poor rate ***,a flower-like MoS_(2)/polyaniline composite electrode(MoS_(2)-PANI)where PANI was grown in situ between layers of MoS_(2)nanosheets was *** thisdesign,the inserted PANI can broaden the layer distance of MoS_(2)to facilitate cation diffusion and pre-vent the restacking of ***,PANI is also expected to increase the conductivity andrelieve the volume changes during repeated charge/discharge *** from that,the MoS_(2)-PANIelectrode delivered a reversible capacity of 561.91 mA h g^(-1) at 5 A g^(-1) in half-cell ***,whencoupled with a mildly expanded graphite(MEG)cathode,the obtained MEG//MoS_(2)-PANI DIB shows ex-cellent rate ability with a reversible discharge capacity of 86.62 mA h g^(-1) and a desirable energy densityof 308.83 W h kg-1 at 20 *** results provide some inspiration for the design of high-rate DIBs.
N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-prop...
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N-doping has significant influence in manipulating the properties of TiO_(2),and this has stimulated the development of N-donor-functionalized titanium-oxo clusters(TOCs)as molecular models to study the structure-property ***,the structural type and photoresponsive application are still limited for such TOCs,especially regarding the high-nuclearity TOCs that contain structure unit of TiO_(2)for ***,we showed the synthesis of a series of high-nuclearity TOCs 1-3 compounds usingπ-conjugated 1,10-phenanthroline(phen)as chromophore and N-donor functional *** 1 features cocrystal structure composed of one[Ti_(26)]~(2+)and half[Ti_(22)]~(2+),which renders it as the first cocrystallized TOC containing two positively charged species and phen-functionalized TOC showing the highest nuclearity up to 37 Ti *** adjusting the synthetic conditions,the individual{Ti_(22)}and{Ti_(26)}clusters can also be isolated as Compounds 2 and 3,*** core structure of{Ti_(22)}is mainly constructed from four lacunary{Ti_(4)}derived from pentagonal{Ti(Ti)_5}unit,while{Ti_(26)}is built from four complete{Ti(Ti)_5}***,a{Ti_8O_(14)}structure unit of anatase TiO_(2)can be identified in{Ti_(26)}.Based on the unique structural features and proper photophysical and photochemical properties of Compounds 1-3,they are applied for photocatalytic *** to the presence of anatase structure unit in{Ti_(26)}and the synergistic effect from{Ti_(22)}and{Ti_(26)},the catalytic performance presents in the order of Compound 1>Compound 3>Compound *** work provides excellent models to understand the structureproperty relationship from the perspective of cocrystallization and Ti-O binding model and will further promote the application of TOCs as functional catalysts for organic transformation.
The production of ferroalloys is a resource-intensive and energy-consuming *** mitigate its adverse environmental effects,steel companies should implement a range of measures aiming at enhancing the utilization rate o...
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The production of ferroalloys is a resource-intensive and energy-consuming *** mitigate its adverse environmental effects,steel companies should implement a range of measures aiming at enhancing the utilization rate of ***,a comprehensive ferroalloy model was proposed,incorporating a prediction model for alloying element yield based on case-based reasoning and support vector machine(CBR-SVM),along with a ferroalloy batching model employing an integral linear programming *** simulation calculations,the prediction model exhibited exceptional predictive performance,with a hit rate of 96.05%within 5%.The linear programming ingredient model proved effective in reducing costs by 20.7%,which was achieved through accurate adjustments to the types and quantities of *** proposed method and system were successfully implemented in the actual production environment of a specific steel plant,operating seamlessly for six *** implementation has notably increased the product quality of the enterprise,with the control rate of high-quality products increasing from 46%to 79%,effectively diminishing the consumption and expenses associated with *** reduced usage of ferroalloys simultaneously reduces energy consumption and mitigates the adverse environmental impact of the steel industry.
This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation *** proposed design scheme combines a Newton-Raphson method with an extended Ka...
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This paper proposes a comprehensive design scheme for the extremum seeking control(ESC)of the unmanned aerial vehicle(UAV)close formation *** proposed design scheme combines a Newton-Raphson method with an extended Kalman filter(EKF)to dynamically estimate the optimal position of the following UAV relative to the leading *** reflect the wake vortex effects reliably,the drag coefficient induced by the wake vortex is considered as a performance ***,the performance function is parameterized by the first-order and second-order terms of its Taylor series *** the excellent performance of nonlinear estimation,the EKF is used to estimate the gradient and the Hessian matrix of the parameterized performance *** output feedback of the proposed scheme is determined by iterative calculation of the Newton-Raphson *** with the traditional ESC and the classic ESC,the proposed design scheme avoids the slow continuous time integration of the *** allows a faster convergence of relative position ***,the proposed method can provide a smoother command during the seeking process as the second-order term of the performance function is taken into *** convergence analysis of the proposed design scheme is accomplished by showing that the output feedback is a supermartingale *** improve estimation performance of the EKF,a improved pigeon-inspired optimization(IPIO)is proposed to automatically tune the noise covariance *** Carlo simulations for a three-UAV close formation show that the proposed design scheme is robust to the initial position of the following UAV.
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