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CCS Chemistry 2024年第10期6卷 2439-2451页

作者： Wei Fu Valentina Pelliccioli Raquel Casares-López Juan M.Cuerva Martin Simon Christopher golz Manuel Alcarazo Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen37077 Göttingen Departamento de Química Orgánica Universidad de GranadaUnidad de Excelencia Química Aplicada a Biomedicina y MedioambienteE-18071 Granada

An expedient synthesis of a series of configurationally stable oxa[5]helicenes,oxa[6]helicenes,and dioxa[6]helicenes has been developed using an intramolecular,highly enantioselective,Au-catalyzed,alkyne hydroarylation *** absolute configuration of the newly prepared structures has been established by crystallography,their inversion barriers have been determined theoretically and experimentally,and their chiroptical properties have been *** of these data with those reported for thia-or carbohelicenes sharing an otherwise identical helical framework enables the establishment of comprehensive correlations between the nature of the embedded(hetero)atom(s)and the magnitude of these *** studies on the postsynthetic functionalization of the oxahelicenes obtained are also ***,siteselective bromination at the 15-position in oxa[5]helicene 5d allows its subsequent manipulation into pyridine-containing aza-oxa[7]helicene 13d;while the two termini of oxa[6]helicene 7d have been intramolecularly cyclised into the pleiadeno[1,12,11-bcde]benzofuran derivative 15d by acidic *** transformations take place without erosion of the enantiopurity.

关键词： Au-catalysis enantioselective synthesis oxa[n]helicenes racemization dynamics postsynthetic functionalization

Design of Industrial Quenching Processes

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材料热处理学报 2004年第5期25卷 527-530页

作者： Nikolai. I. KOBASKO george .e. totten Intensive Technologies Ltd Kiev UKRAINEG.E.Totten & Associate LLC Seattle USA

The method of designing industrial processes of quench cooling, in particular, the speed of the conveyor movement with regard to shape and sizes of parts to be quenched, thermal and physical properties of material and cooling capacity of quenchants has been developed. The suggested designing method and databases are the basis for the complete automation of industrial processes of quench cooling, especially for continuous conveyor lines, with the purpose of making high-strength materials. The process is controlled by infrared technique.

关键词：淬火速度控制数据库冷却能力质量控制

The signal-transduction pathways of the peripheral olfactory organ and their impairment in vertebrates

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Aquaculture and Fisheries 2024年第3期9卷 388-403页

作者： Arash Shahriari Bouthaina Aoudi Keith B.Tierney College of Natural and Applied Sciences Faculty of ScienceBiological SciencesEdmontonABT6G 2E9Canada Department of Civil and environmental engineering University of AlbertaEdmontonABT6G 1H9Canada College of Health Sciences School of Public HealthEdmontonABT6G 1C9Canada

Animals rely on olfaction to detect and process invaluable chemical information about their *** olfaction to function,chemicals must first be detected,which leads to the activation of signal-transduction pathways at the peripheral olfactory *** the olfactory system is in direct contact with the environment,the system is constantly vulnerable to damage by contaminants entering the atmosphere or *** may have a variety of effects,including disrupting olfactory signals generated during chemical detection,or altering numerous targets along the signal transduction *** any impairment of chemical detection,animals may be unable to rely on olfaction to make correct decisions about their environment and thus their *** other reviews have focussed on olfactory toxicology in general,here we specifically explore how contaminants may affect the signal-transduction pathways at various points and link those changes to olfactory functionality across vertebrates with a focus on fishes.

关键词： Olfaction Signal-transduction Vertebrate Fish

Model Predictive Current Control for Low-Cost Shunt Active Power Filter

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CSee Journal of Power and energy Systems 2024年第4期10卷 1589-1598页

作者： Ali A.Abdel-Aziz Mohamed A.elgenedy Barry W.Williams the electronic and electrical engineering Department Strathclyde UniversityGlasgowG11XQUK School of Computing Engineering and the Built Environment(SCEBE)Glasgow Caledonian UniversityGlasgowG40BAUK

Performance of a three-phase shunt active power filter(SAPF)relies on the capability of the controller to track the reference ***,designing an accurate current controller is crucial to guarantee satisfactory SAPF *** paper presents a model predictive current controller(MPCC)for a low-cost,four-switch,shunt active power filter for power quality improvement.A four-switch,B4,converter topology is adopted as an SAPF,hence offering a simple,robust,and low-cost *** addition,to further reduce overall cost,only two interfacing filter inductors,instead of three,are used to eliminate switching current *** proposed SAPF model MPCC is detailed for implementation,where simulation and experimental results validate effectiveness of the proposed control algorithm showing a 20%improvement in total harmonic distortion compared with a conventional hysteresis band current controller.

关键词： Four-switch converter harmonic distortion model predictive current control power quality shunt active power filter

Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator

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Petroleum Science 2024年第2期21卷 1346-1353页

作者： Jens Müller Sebastian Leonow Johannes Schulz Christian Hansen Martin Monnigmann Ruhr-Universitat Bochum Universit atsstraûe 150Bochum44801Germany SeePeX gmbH Scharnh olzstraûe 344Bottrop46240Germany

This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation.

关键词： Backflow Progressing cavity pump Virtual sensor Wear

Photoelectrochemical Iron-Catalyzed C(sp^(3))-H Borylation of Alkanes in a Position-Selective Manner

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CCS Chemistry 2024年第6期6卷 1430-1438页

作者： Wen Wei Bin Wang Simon L.Homölle Jinbin Zhu Yanjun Li Tristan von Münchow Isaac Maksso Lutz Ackermann Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen37077 Göttingen

Catalytic C-H borylation is of prime topical importance,since easily available feedstock chemicals can thereby be transformed into valuable transient functional groups in the absence of directing ***,we disclose an iron-catalyzed C(sp^(3))-H borylation of simple,non-prefunctionalized alkanes,providing access to value-added products in a single step by means of *** power of merging photo-and electrochemistry was mirrored by ample scope and exceedingly mild reaction ***,an outstanding position-selectivity in favor of primary C(sp^(3))-H proved viable within the photoelectrochemical borylation through a chemo-selective anodic overoxidation *** ferro-photoelectrochemistry strategy avoids toxic precious transition metals,enabling C(sp^(3))-H borylations in a site-selective fashion.

关键词： photoelectrocatalysis C(sp^(3))-H borylation iron catalysis position-selectivity chlorine radical

Metallurgical Forensics: Investigating a Superheater Tube Failure in Industrial Process Plants

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World Journal of engineering and Technology 2024年第3期12卷 742-758页

作者： Kok Toong Leong engineering Department QSM Associates Singapore

A metallurgical forensic investigation was conducted to determine the cause of a failed superheater tube. Analysis techniques by Visual examination, energy Dispersive X-ray Analysis, Mechanical Testing and Metallographic Investigation were conducted, together with a comparative study from an inlet elbow section that did not fail. The superheater tube suffered premature failure after being in service for about two years. It was concluded that the failed tube underwent overheating, corrosion-erosion, embrittlement, and eventual failure under its internal pressure by stress rupture. The analysis revealed intergranular cracks, window fracture features and spheroidization of pearlite with grain growth. A possible contribution to embrittlement was from copper. Follow-ups and recommendations were provided, as well as covering materials, inspection, and operational considerations.

关键词： Superheater Tubes Thermal Degradation Corrosion-erosion embrittlement Stress Rupture

Calibration of the DeM sliding friction and rolling friction parameters of a cohesionless bulk material

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Particuology 2024年第9期92卷 126-139页

作者： Jonatan Marín Pérez Tugrul Comlekci Yevgen gorash Donald MacKenzie University of Strathclyde 75 Montrose StreetG11XJGlasgowUnited Kingdom

The discrete element method(DeM)has become a valuable tool for understanding the mechanical behaviour of granular assemblies,however,the accuracy of the DeM simulations depends on several interaction parameters such as the sliding friction and rolling friction ***,these parameters are estimated using bulk calibration approach(BCA)where the draw down test has been suggested as an effective way to approach these *** test provides up to four bulk criteria,the angle of repose,shear angle,mass flow rate and the mass loss which are used to narrow down the possible ***,there is still more research needed around it to fully understand how this methodology *** experimental and numerical study was carried out using the draw down test to assess the influence of different mass flow rates and particle shapes on DeM parameters for a cohesionless bulk *** is concluded that use of multi-sphere particles and three aperture sizes in the draw down test to calibrate the sliding and rolling friction parameters of a cohesionless bulk material can converge to a small feasible region in which a single combination of the friction coefficients can be *** calibrated sliding and rolling friction coefficients were validated using multi-sphere particles,where the maximum deviation was 5.9%from the experimental values.

关键词： Discrete element method Calibration Draw down Sliding friction Rolling friction Particle shape

Robust Machine Learning Mapping of seMg Signals to Future Actuator Commands in Biomechatronic Devices

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Journal of Bionic engineering 2024年第1期21卷 270-287页

作者： Ali Nasr Sydney Bell Rachel L.Whittaker Clark R.Dickerson John McPhee Systems Design engineering University of WaterlooWaterloo N2L 3G1Canada Kinesiology and Health Sciences University of WaterlooWaterloo N2L3G3Canada

A machine learning model for regression of interrupted Surface electromyography(seMg)signals to future control-oriented signals(e.g.,robot’s joint angle and assistive torque)of an active biomechatronic device for high-level myoelectric-based hierarchical control is proposed.A Recurrent Neural Network(RNN)was trained using output data,initially obtained from offline optimization of the biomechatronic(human–robot)device and shifted by the prediction *** input of the RNN consisted of interrupted seMg signals(to mimic signal disconnections)and previous kinematic signals of the assistive *** RNN with a 0.1-s prediction horizon could predict the control-oriented joint angle and assistive torque with 92%and 86.5%regression accuracy,respectively,for the test *** proposed approach permits a fast,predictive,and direct estimation of control-oriented signals instead of an iterative process that optimizes assistive torque in the inverse dynamic simulation of a multibody human–robot *** with these interrupted input signals significantly improves the regression accuracy in the case of seMg signal *** Robust Predictive Control-oriented Machine Learning(Robust-MuscleNeT)model can support volitional high-level myoelectric-based control of biomechatronic devices,such as exoskeletons,prostheses,and assistive/resistive *** work should study the application to prosthesis control as well as the repeatability of the high-level controller with electrode *** low-level hierarchical controller that manages the human–robot interaction,the assistance/resistance strategy,and the actuator coordination should also be studied.

关键词： Myoelectric-based control-Surface electromyography Machine learning Multibody system dynamics exoskeleton Bionic

Sustainable management of campus fallen leaves through low-temperature pyrolysis and application in Pb immobilization

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Journal of environmental Sciences 2024年第5期139卷 281-292页

作者： Rongli Tan Ke Li Yue Sun Xiaoliang Fan Zhengtao Shen Lingyi Tang School of environment Nanjing UniversityNanjing 210023China School of Chemistry and Chemical engineering Nanjing UniversityNanjing 210023China School of earth and engineering Sciences Nanjing UniversityNanjing 210023China Department of earth and Atmospheric Sciences University of AlbertaEdmonton T6G 2E3Canada

Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen *** fallen leaf biochar at a low temperature is a candidate *** this study,six common types of fallen leaves on the campus were pyrolyzed at 300℃.The obtained biochars were characterized and the adsorption mechanisms of lead(Pb)by the fallen leaf biochars were *** adsorption capacity of leaf biochar for Pb was relatively high,up to 209 mg/g(Yulania denudata leaf biochar).Adsorption of Pb onto active sites was the rate-limiting step for most leaf *** for Platanus leaf biochar,intraparticle diffusion of Pb^(2+)dominated owing to the lowest adsorption ***,the highest exchangeable Pb fraction(27%)indicated its potential for removing aqueous Pb^(2+).ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead ***,they were suitable for soil heavy metal *** study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation.

关键词： Fallen leaves Waste management Biochar Lead removal Sorption Circular campus