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Comprehensive Exergoeconomic Analysis and Optimization of a Novel Zero-Carbon-Emission Multi-Generation System based on Carbon dioxide Cycle

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Journal of Thermal Science 2024年第3期33卷 1065-1081页

作者： SUN Yan LI Hongwei WANG di DU Changhe School of Energy and Power Engineering Northeast Electric Power UniversityJilin132012China School of Automation Engineering Northeast Electric Power UniversityJilin132012China Xi’an Institute of Electromechanical Information Technology Xi’an710065China

This paper aims to conduct a comprehensive exergoeconomic analysis of a novel zero-carbon-emission multi-generation system and propose a fast optimization method combined with machine *** detailed exergoeconomic analysis of a novel combined power,freshwater and cooling multi-generation system is performed in this *** exergoeconomic analysis model is established by exergy flow theory.A comprehensive exergy,exergoeconomic and environmental analysis is carried *** critical decision variables are researched to bring out effects on the multi-generation system exergoeconomic performance.A novel fast optimization method combining genetic algorithm and Bagging neural network is *** advanced nature comparison is made between the proposed system and four similar *** display that increasing the turbine inlet temperature can improve exergy efficiency and decrease the total product unit *** multi-generation system exergy destruction directly determines exergy efficiency and total exergy destruction cost *** total product unit cost in the cost optimal design case is reduced by 7.7%and 25%,respectively,compared with exergy efficiency optimal design case and basic design *** with four similar cases,the proposed multi-generation system has great advantages in thermodynamic performance and exergoeconomic *** paper can provide research methods and ideas for performance analysis and fast optimization of multi-generation system.

关键词： waste heat recovery exergoeconomic analysis supercritical carbon dioxide optimization machine learning

A molecular insight into coke formation process of vacuum residue in thermal cracking reaction

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Petroleum Science 2024年第3期21卷 2130-2138页

作者： Ji-Guang Li Xin Guo Huan-di Hou Heavy Oil Processing Department Sinopec Research Institute of Petroleum Processing Co.LtdBeijing100083China

Understanding the coking behaviors has been considered to be really essential for developing better vacuum residue processing technologies.A battery of thermal cracking tests of typical vacuum residue at 410℃ with various reaction time were performed to evaluate the coke formation *** total yields of ideal components including naphtha,atmospheric gas oil(AGO)and vacuum gas oil(VGO)of thermal cracking reactions increased from 10.89%to 40.81%,and the conversion ratios increased from8.05%to 43.33%with increasing the reaction time from 10 to 70 *** asphaltene content increased from 12.14%to a maximum of 22.39%and then decreased,and this maximum of asphaltene content occurred at the end of the coking induction *** asphaltenes during the coking induction period,at the end and after coking induction period of those tested thermal cracking reactions were characterized to disclose the structure changing rules for coke formation process,and the coke formation pathways were discussed to reveal the coke formation process at molecular level.

关键词： Vacuum residue Thermal cracking Asphaltene Coking induction period Sulfur Nitrogen

Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

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Chinese Journal of Polymer Science 2024年第9期42卷 1360-1367,I0008页

作者： You-Cai Xue Yi-Ming Yang di Jia Beijing National Laboratory for Molecular Sciences Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Polyampholyte gels,which have hierarchical structures,exhibit excellent self-healing properties and have great promise for biomaterials and *** investigated the relationship between microscopic structures and macroscopic viscoelastic properties of polyampholyte gels and found three factors influencing their viscoelastic properties,including the chemical crosslinking bonds,topological entanglements controlled by monomer concentration,and the ionic *** strength plays a major role on the strength of ionic bonds.A crossover point of elastic modulus and loss modulus was observed in the dynamic frequency sweeps at low monomer concentration or low chemical crosslinking density for gels with intermediate strength of ionic *** solid-liquid transition signaled by the crossover point is a typical feature of dynamic associated gels,representing the dynamical association-dissociation of the ionic bonds and full relaxation of the topological entanglements in the gel *** the crossover point disappears when the ionic bonds are too weak or too strong to form“permanent”***,in the non-linear yielding measurement,gels with intermediate strength of the ionic bonds are ductile and yield at very large shear strain due to the self-healing properties and the dynamic association-dissociation of the ionic *** the self-healing properties disappear when the ionic bond strength is too weak or too *** work reveals the mechanism of how the dynamic association-dissociation of ionic bonds influences both the linear and non-linear viscoelastic properties of the polyampholyte gels.

关键词： Polyampholyte gel Ionic bond Topological entanglement Self-healing Hierarchical structure

Design method and experimental study of a cathode tool with an extremely high leveling ratio for electrochemical machining of blisk

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Chinese Journal of Aeronautics 2024年第4期37卷 593-608页

作者： Moqi SHEN Jia LIU Jingtao WANG di ZHU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To obtain final parts with the desired dimensional accuracy and repeatability via electrochemical machining(ECM), the machining process must enter an ECM balanced state. However,for the ECM processing of blisk, a key component of aerospace engines, the surface of the blade blank often has an uneven allowance distribution due to the narrow passage of the cascade. It is difficult to remedy this issue in subsequent processing steps, which is necessary to ensure the dimensional accuracy and repeatability of the final blade profile. To solve this problem, electrolytic machining must be preceded by electrolytic shaping, which requires cathode tools with large leveling ratios to quickly homogenize the blank surface of the blade. In this study, to obtain a cathode tool with an extremely high leveling ratio, a design method based on the variation in the electrode gap in the non-equilibrium electrolytic state is proposed, and a dissolution model based on the nonequilibrium state is established. In this design method, the allowance on the blank to be machined is first divided into many discrete allowances with the normal direction. The initial machining clearance, feed rate, and total machining time are then calculated using classical ECM equilibrium state theory based on the maximum allowance. Meanwhile, the point coordinates of the cathode tool at maximum allowance can be determined. The non-equilibrium model can then be used to calculate the relative coordinate positions corresponding to the remaining discrete allowances. Finally, the entire cathode tool profile is designed. Simulations, fundamental experiments, and blisk unit workpiece experiments were carried out to validate the design approach. In the simulated processing of the plane workpiece, the leveling ratio of the cathode tool designed by the proposed method(0.77)was 83% higher than that of the cathode tool designed using the traditional method. The simulation results were confirmed by processing experiments. In t

关键词： Electrochemical machining(ECM) Non-equilibrium machining Large leveling ratios Cathode design Finite element simulation Blisk

Predicting the activity of single atom catalysts

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Science China Chemistry 2024年第9期67卷 2792-2793页

作者： Giovanni di Liberto Gianfranco Pacchioni dipartimento di Scienza dei Materiali Universitàdi Milano-Bicoccavia R.Cozzi 5520125 MilanoItaly

For a long time,the existence of single-atom catalysts(SACs),consisting of isolated atoms stabilized in a specific support,was not detected due to limitations in available characterization *** the past two decades,however,the ability to synthesize and characterize these systems has opened the way toward designing and testing a new class of potential catalysts[1].

关键词： catalysts limitations testing

Real-time hybrid method for maneuver detection and estimation of non-cooperative space targets

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Astrodynamics 2024年第3期8卷 437-453页

作者： Peng Zhang di Wu Hexi Baoyin School of Aerospace Engineering Tsinghua UniversityBeijing100084China

A novel hybrid scheme for the maneuver detection and estimation of a noncooperative space target was proposed in this *** optical measurements,together with the range and range rate measurements from the ground-based radars,were used in the tracking *** many tracking scenarios,radar resources for non-cooperative targets are constrained,particularly for near-earth targets,where multiple objects can only be tracked by a single radar at a *** limitation hinders the accurate estimation of noncooperative target maneuvers,and can at times result in target *** literature has addressed this issue to some extent through various maneuvering target-tracking *** address this problem,a hybrid maneuver detection and estimation method that combines the input detection and estimation extended kalman filter and the weighted nonlinear least squares method is *** results demonstrate that the proposed method outperforms the previous method,offering more accurate and efficient estimations.

关键词： orbit determination unknown maneuver maneuver detection and estimation extended Kalman filter weighted least squares method(WLS)

Influence of High-Density Bedding Plane Characteristics on Hydraulic Fracture Propagation in Shale Oil Reservoir

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3051-3071页

作者： Xiao Yan di Wang Haitao Yu State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Beijing102206China State Energy Center for Shale Oil Research and Development Beijing102206China Department of Geotechnical Engineering College of Civil Engineering Tongji UniversityShanghai200092China Petroleum Exploration and Production Research Institute SINOPECBeijing102206China Key Laboratory of Deep Earth Science and Engineering(Sichuan University) Ministry of EducationChengdu610065China

The existence of high-density bedding planes is a typical characteristic of shale oil *** the behavior of hydraulic fracturing in high-density laminated rocks is significant for promoting shale oil *** this study,a hydraulic fracturing model considering tensile failure and frictional slip of the bedding planes is established within the framework of the unified pipe-interface element method(UP-IEM).The model developed for simulating the interaction between the hydraulic fracture and the bedding plane is validated by comparison with experimental *** hydraulic fracturing patterns in sealed and unsealed bedding planes are ***,the effects of differential stress,bedding plane permeability,spacing,and the friction coefficient of the bedding plane are *** results showed that a single main fracture crossing the bedding planes is more likely to form in sealed bedding planes under high differential *** decrease in bedding plane permeability and the increase in the friction coefficient also promote the fracture propagating perpendicular to the bedding *** with high-density bedding planes has a poorer fracturing effect than that with low-density bedding planes,as the hydraulic fracture is prone to initiate and propagate along the bedding ***,higher injection pressure is needed to maintain fracture propagation along the *** increase in bedding density will lead to a smaller fracturing *** fluid seepage into the bedding planes slows shale *** is recommended that increasing the injection flow rate,selecting alternative fracturing fluids,and employing multi-well/multi-cluster fracturing may be efficient methods to improve energy production in shale oil reservoirs.

关键词： Hydraulic fracturing bedding planes shale unified pipe-interface element method

OsPDR20 is an ABCG metal transporter regulating cadmium accumulation in rice

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Journal of Environmental Sciences 2024年第2期136卷 21-34页

作者： He Li Chao Li di Sun Zhi Min Yang Department of Biochemistry and Molecular Biology College of Life SciencesNanjing Agricultural UniversityNanjing 210095China

Cadmium(Cd)is a non-essential toxic heavy metal,seriously posing high environmental risks to human *** genetic resources relevant to functional genes is important for understanding the metal absorption and accumulation in crops and bioremediation of Cd-polluted *** study investigated a functionally uncharacterized ATP binding cassette transporter G family(ABCG)gene encoding a Pleiotropic Drug Resistance 20(PDR20)type metal transporter which is localized to the plasma membrane of ***20 was transcriptionally expressed in almost all tissues and organs in lifespan and was strongly induced in roots and shoots of young rice under Cd *** expression of OsPDR20 in a yeast mutant ycf1 sensitive to Cd conferred cellular tolerance with less Cd *** of OsPDR20 by RNA interference(RNAi)moderately attenuated root/shoot elongation and biomass,with reduced chlorophylls in rice grown under hydroponic medium with 2 and 10μmol/L Cd,but led to more Cd accumulation.A field trial of rice grown in a realistic Cd-contaminated soil(0.40 mg/kg)showed that RNAi plants growth and development were also compromised compared to wild-type(WT),with smaller panicles and lower spikelet fertility but little effect on yield of ***,OsPDR20 suppression resulted in unexpectedly higher levels of Cd accumulation in rice straw including lower leaves and culm and *** results suggest that OsPDR20 is actively involved in Cd accumulation and homeostasis in rice *** increased Cd accumulation in the RNAi plants has the potential application in phytoremediation of Cd-polluted wetland soils.

关键词： Rice ABCG transporter Cadmium accumulation Phytoremediation

Streamflow abrupt change and the driving factors in glacierized basins of Tarim Basin,Northwest China

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Advances in Climate Change Research 2024年第1期15卷 75-89页

作者： Cheng-De YANG Min XU Shi-Chang KANG Cong-Sheng FU Wei ZHANG di-di HU State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210000China

A climate transition towards warm-wet conditions in Northwest China has drawn much *** continuous climate change and universal glacier degradation,increasing water-related hazards and vulnerability have become one of the important problems facing the Tarim ***,the impacts of the climate transition on streamflow abrupt change and extreme hydrological events were less discussed,especially in glacial *** the present study,the discharge datasets in four glacial basins of Tarim Basin from 1979 to 2018 were constructed using the GRU-GSWAT+model *** differences in streamflow characteristics,the shift of hydrological extreme pattern,and potential changes of the controlling factors before and after the abrupt changes were *** results indicated that the abrupt change point(ACP)in streamflow occurred in 2000 in the Qarqan River Basin,2002 in the Weigan River Basin,and 1994 in the Aksu River Basin and the Yarkant River Basin.A general decrease in streamflow before the ACP has shifted to a notable upward trend in the Qarqan River Basin and the Aksu River Basin,while minor upward fluctuations were observed in other ***,the hydrological characteristics in extreme events vary dramatically before and after the ACPs,characterized by a pronouncing shift from drought-dominant pattern to wet events dominated *** driven climate factors have been altered after the ACPs with notable spatial heterogeneity,in which temperature remained as the dominant role in meltwater-dominated basins while the influence of precipitation has increased after the ACPs,whereas the sensitivity of temperature on streamflow change has been enhanced in basins dominated by precipitation such as the Qarqan River *** to the evident warming-wetting trend and glacier compensation effect,both the inter-annual and intra-annual streamflow fluctuations can be efficiently smoothed in basins with a high glacier area ratio(GAR).These findings provide a

关键词： Abrupt change Streamflow Hybrid model Tarim Basin Glacier