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Optimized parameters of downhole all-metal PDM based on genetic algorithm

Petroleum Science 2024年第4期21卷 2663-2676页

作者： Jia-Xing lu Ling-Rong Kong yu Wang Chao Feng yu-Lin Gao China University of Geosciences (Beijing) Key Laboratory on Deep Geo-Drilling Technology of Ministry of Natural Resources

Currently, deep drilling operates under extreme conditions of high temperature and high pressure,demanding more from subterranean power motors. The all-metal positive displacement motor, known for its robust performance, is a critical choice for such drilling. The dimensions of the PDM are crucial for its performance output. To enhance this, optimization of the motor's profile using a genetic algorithm has been undertaken. The design process begins with the computation of the initial stator and rotor curves based on the equations for a screw cycloid. These curves are then refined using the least squares method for a precise fit. Following this, the PDM's mathematical model is optimized, and motor friction is assessed. The genetic algorithm process involves encoding variations and managing crossovers to optimize objective functions, including the isometric radius coefficient, eccentricity distance parameter,overflow area, and maximum slip speed. This optimization yields the ideal profile parameters that enhance the motor's output. Comparative analyses of the initial and optimized output characteristics were conducted, focusing on the effects of the isometric radius coefficient and overflow area on the motor's performance. Results indicate that the optimized motor's overflow area increased by 6.9%, while its rotational speed reduced by 6.58%. The torque, as tested by Infocus, saw substantial improvements of38.8%. This optimization provides a theoretical foundation for improving the output characteristics of allmetal PDMs and supports the ongoing development and research of PDM technology.

关键词： Positive displacement motor Genetic algorithm Profile optimization Matlab programming Overflow area

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The role of exosomes in adult neurogenesis:implications for neurodegenerative diseases

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Neural Regeneration Research 2024年第2期19卷 282-288页

作者： Zhuoyang yu Yan Teng Jing Yang lu Yang Institute of Neurology Sichuan Provincial People’s HospitalUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Laboratory of Aging Research School of MedicineUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina

Exosomes are cup-shaped extracellular vesicles with a lipid bilayer that is approximately 30 to 200 nm in *** are widely distributed in a range of body fluids,including urine,blood,milk,and *** exert biological function by transporting factors between different cells and by regulating biological pathways in recipient *** an important form of intercellular communication,exosomes are increasingly being investigated due to their ability to transfer bioactive molecules such as lipids,proteins,mRNAs,and microRNAs between cells,and because they can regulate physiological and pathological processes in the central nervous *** neurogenesis is a multistage process by which new neurons are generated and migrate to be integrated into existing neuronal *** the adult brain,neurogenesis is mainly localized in two specialized niches:the subventricular zone adjacent to the lateral ventricles and the subgranular zone of the dentate *** increasing body of evidence indicates that adult neurogenesis is tightly controlled by environmental conditions with the *** recent studies,exosomes released from different sources of cells were shown to play an active role in regulating neurogenesis both in vitro and in vivo,thereby participating in the progression of neurodegenerative disorders in patients and in various disease ***,we provide a state-of-the-art synopsis of existing research that aimed to identify the diverse components of exosome cargoes and elucidate the therapeutic potential of exosomal contents in the regulation of neurogenesis in several neurodegenerative *** emphasize that exosomal cargoes could serve as a potential biomarker to monitor functional neurogenesis in *** addition,exosomes can also be considered as a novel therapeutic approach to treat various neurodegenerative disorders by improving endogenous neurogenesis to mitigate neuronal loss in the central nervous system.

关键词： adult neurogenesis Alzheimer’s disease amyotrophic lateral sclerosis exosome Huntington’s disease neurodegenerative disease neurogenic niches Parkinson’s disease

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Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

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Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： yue lu yu-quan Zhang Zhong-wei He yuan Zheng College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the instability of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

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Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG Wenyu LI Wei lu yu REN Qiangqiang Lyu Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel *** gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of ***,there is an urgent need to investigate methods for its *** combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual *** order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

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Segregation of binary particles in gas-solid fluidized bed

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 113-121页

作者： Yaxiong yu Feng lu Xuan He Fei Wei Chenxi Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China Ordos Laboratory Ordos 017010China Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China

Particle segregation and mixing behavior play a crucial role in industrial *** study investigates the saturated jetsam fraction,which indicates the maximum capacity of flotsam to entrain jetsam,in an initially separated binary fluidized bed with particle size *** to the value of saturated jetsam fraction,three distinct regimes-segregation,mixing,and an intermediate regime-are ***,intriguing relationships between the saturated jetsam fraction and superficial gas velocity are observed,exhibiting monotonic trends in both the segregation and mixing regimes,while a unique volcano-shaped curve in the intermediate ***,a comprehensive entrainment model based on two-fluid model elucidates the observed phenomena,emphasizing the significance of mixing behavior in fluidized layer on the saturated jetsam *** work offers potential insights for evaluating segregation in industrial applications.

关键词： fluidized bed segregation binary bubbles entrainment

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Scaling laws governing the elastic properties of 3D graphenes

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Science China(Technological Sciences) 2024年第6期67卷 1748-1756页

作者： LI Ming lu Guo yu HaoDong LI MengLei ZHENG FaWei Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing100081China Beijing Key Lab of Nanophotonics&Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of TechnologyBeijing100081China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing100088China Department of Physics Capital Normal UniversityBeijing100048China

In this study,we comprehensively investigated the scaling law for elastic properties of three-dimensional honeycomb-like graphenes(3D graphenes)using hybrid neural network potential-based molecular dynamics simulations and theoretical *** elastic constants were obtained as functions of honeycomb hole size,denoted by the graphene wall length *** five independent elastic constants in the large-L limit are proportional to L^(-1).The associated coefficients are combinations of elastic constants of two-dimensional ***-order terms including L^(-2)and L^(-3)emerge for finite L *** have three origins,the distorted areas close to the joint lines of 3D graphenes,the variation in solid angles between graphene plates,and the bending distortion of graphene ***,the chirality becomes essential with decreasing L because the joint line structures are different between the armchair and zigzag-type 3D *** findings provide insights into the elastic properties of graphene-based superstructures and can be used for further studies on graphene-based materials.

关键词： scaling law neural network elastic properties 3D graphene

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Developing risk models and subtypes of autophagy-associated LncRNAs for enhanced prognostic prediction and precision in therapeutic approaches for liver cancer patients

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Oncology Research 2024年第4期32卷 703-716页

作者： lu ZHANG JINGUO CHU yuSHAN yu Department of General Practice The First Affiliated Hospital of Ningbo UniversityNingboChina

Background:Limited research has been conducted on the influence of autophagy-associated long non-coding RNAs(ARLncRNAs)on the prognosis of hepatocellular carcinoma(HCC).Methods:We analyzed 371 HCC samples from TCGA,identifying expression networks of ARLncRNAs using autophagy-related *** for prognostically relevant ARLncRNAs involved univariate Cox regression,Lasso regression,and multivariate Cox regression.A Nomogram was further employed to assess the reliability of Riskscore,calculated from the signatures of screened ARLncRNAs,in predicting ***,we compared drug sensitivities in patient groups with differing risk levels and investigated potential biological pathways through enrichment analysis,using consensus clustering to identify subgroups related to ***:The screening process identified 27 ARLncRNAs,with 13 being associated with HCC ***,a set of signatures comprising 8 ARLncRNAs was successfully constructed as independent prognostic factors for *** in the high-risk group showed very poor prognoses in most clinical *** Riskscore was closely related to immune cell scores,such as macrophages,and the DEGs between different groups were implicated in metabolism,cell cycle,and mitotic ***,high-risk group patients demonstrated a significantly lower IC50 for Paclitaxel,suggesting that Paclitaxel could be an ideal treatment for those at elevated risk for *** further identified C2 as the Paclitaxel subtype,where patients exhibited higher Riskscores,reduced survival rates,and more severe clinical ***:The 8 signatures based on ARLncRNAs present novel targets for prognostic prediction in *** drug candidate Paclitaxel may effectively treat HCC by impacting ARLncRNAs *** the identification of ARLncRNAsrelated isoforms,these results provide valuable insights for clinical exploration of autophagy mechanisms in HCC pathogenesis and offer potential av

关键词： Autophagy Hepatocellular carcinoma(HCC) Prognosis Precision medicine Paclitaxel

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Security estimation of LWE via BKW algorithms

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Cybersecurity 2024年第1期7卷 71-87页

作者： yu Wei Lei Bi Xianhui lu Kunpeng Wang SKLOIS Institute of Information EngineeringCASBeijingChina School of Cyber Security University of Chinese Academy of SciencesBeijingChina

The Learning With Errors(LWE)problem is widely used in lattice-based cryptography,which is the most promising post-quantum cryptography *** are a variety of LWE-solving methods,which can be classified into four groups:lattice methods,algebraic methods,combinatorial methods,and exhaustive *** Blum–Kalai–Wasserman(BKW)algorithm is an important variety of combinatorial algorithms,which was first presented for solving the Learning Parity With Noise(LPN)problem and then extended to solve *** this paper,we give an overview of BKW algorithms for solving *** introduce the framework and key techniques of BKW algorithms and make comparisons between different BKW algorithms and also with lattice methods by estimating concrete security of specific LWE *** also briefly discuss the current problems and potential future directions of BKW algorithms.

关键词： Post-quantum cryptography Learning with errors problem Lattice-based cryptography Security estimation

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Optical scattering imaging with sub-nanometer precision based on position-ultra-sensitive giant Lamb shift

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 96-105页

作者： Zeyang Liao yu-Wei lu Wei Li Xue-Hua Wang State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

The Lamb shift of a quantum emitter in close proximity to a plasmonic nanostructure can be three or more orders of magnitude larger than that in the free space and is ultra-sensitive to the emitter position and *** demonstrate that this large Lamb shift can be sensitively observed from the scattering or absorption spectrum dip shift of the coupled system when the plasmonic nanoparticle or tip scans the *** these observations,we propose a scanning optical scattering imaging method based on the plasmonic-enhanced Lamb shift with achieves sub-nanometer *** method is based on the scattering or absorption spectrum of the plasmon-emitter coupling system,which is free of the fluorescence quenching problem and easier to implement in a plasmon-emitter coupling *** addition,our scheme works even if the quantum emitter is slightly below the dielectric surface,which can bring about broader applications,such as detecting atoms and molecules or quantum dots above or under a surface.

关键词： Lamb shift plasmon optical scattering imaging

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Capturing and visualizing the phase transition mediated thermal stress of thermal barrier coating materials via a cross-scale integrated computational approach

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Journal of Advanced Ceramics 2024年第4期13卷 413-428页

作者： Mengdi Gan Tianlong lu Wei yu Jing Feng Xiaoyu Chong Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The generation and evaluation of severely high thermal stress(σ)is known to be responsible for failure of thermal barrier coatings(TBCs)during thermal *** is crucial and challenging to capture fluctuations inσcaused by the phase transition,which has motivated us to develop a high-throughput multiscale evaluation method forσin TBCs that considers the phase transition of the top ceramic materials by coupling first-principles calculations with finite element *** method quantitatively evaluates and visualizesσof the real TBC structure under thermal cycling by multifield ***,the thermophysical properties calculated by the first-principles calculations consider the effects of temperature and phase transition,which not only reduces the cost of obtaining data but also has a more physical *** this work,rare earth tantalites(RETaO_(4))are introduced as ceramic layers,and the results demonstrate thatσundergoes a rapid escalation near the phase transition temperature(T_(t)),particularly in the TBCs_GdTaO_(4) system,where it rises from 224 to 435 *** discontinuity inσmay originate from the significant alterations in Young’s modulus(increase by 27%–78%)and thermal conductivity(increase by 53%–146%)near T_(t).The TBCs_NdTaO_(4) and TBCs_SmTaO_(4) systems exhibit noteworthy temperature drop gradients and minimalσfluctuations,which are beneficial for extending service lifetime of *** approach facilitates the prediction of failure mechanisms and provides theoretical guidance for the reverse design of TBC materials to obtain low thermal stress systems.

关键词： thermal conductivity first-principles calculations thermodynamics thermal stress thermophysical properties

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