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Base Pressure Control with Semi-Circular Ribs at Critical mach Number

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Fluid Dynamics & materials Processing 2024年第9期20卷 2007-2028页

作者： Ambareen khan Sher Afghan khan Mohammed Nishat Akhtar Abdul Aabid Muneer Baig School of Aerospace Engineering Universiti Sains MalaysiaPenang11600Malaysia Department of Mechanical and Aerospace Engineering Faculty of EngineeringInternational Islamic University MalaysiaKuala Lumpur59000Malaysia Department of Engineering management College of EngineeringPrince Sultan UniversityP.O.Box 66833Riyadh11586Saudi Arabia

When better fuel-air mixing in the combustion chamber or a reduction in base drag are required in vehicles,rockets,and aeroplanes,the base pressure control is *** the base pressure and drag is necessary in both *** this work,semi-circular ribs with varying diameters(2,4,and 6 mm)positioned at six distinct positions(0.5D,1D,1.5D,2D,3D,and 4D)inside a square duct with a side of 15 mm are proposed as an efficient way to apply the passive control ***-depth research is done on optimising rib size for various rib *** to this study,the base pressure rises as rib height ***,the optimal location for the semi-circular ribs with a diameter of 2 mm is at *** 1D location appears to be optimal for the 4 mm size as *** the 6 mm size,however,the 4D position fills this function.

关键词： Base pressure nozzle pressure ratio base drag sonic mach number passive control

Supported Recyclable Metal-free Frustrated Lewis Pair Catalyst for Catalytic Hydrogenation of Substituted Pyridines to Piperidines

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Chemical Research in Chinese Universities 2024年第4期40卷 682-689页

作者： ma Shaohua TANG Zhiyong CAS Key Laboratory for Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P.R.China University of Chinese Academy of Sciences Beijing100049P.R.China

The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic *** this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2,*** work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.

关键词： Pyridine hydrogenation Frustrated Lewis pair Conjugated microporous polymer

A new gravitational theory and dark matter problem

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Communications in Theoretical Physics 2024年第6期76卷 129-136页

作者： Xiong Zhao Yongge ma Department of Physics Beijing Normal UniversityBeijing 100875China

We propose a new gravitational theory with torsion based on Riemann-Cartan geometry,in which all physical quantities are *** addition to the spacetime metric,the gravitational degrees of freedom in this theory also include the torsion and two scalar *** energy-momentum tensor of the matter fields in this theory is also proposed.A spherically symmetric static vacuum solution of the theory is *** turns out that this solution can fit the observational data of the rotation curve outside the stellar disk in the Milky ***,the galactic dark matter may just be the gravitational effect of the theory with torsion.

关键词： gravity torsion dark matter

Catalytic recycling of polyesters via a binuclear catalyst

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Science China Chemistry 2024年第2期67卷 426-427页

作者： Bo Sun Ding ma Beijing National Laboratory for Molecular Science New Cornerstone Science LaboratoryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

Plastics play a crucial role in modern society life. While the increasing use of plastics and rapid accumulation of plastic waste in nature environment have caused severe environmental crisis and the waste of carbon resources. Catalytic upcycling is a promising approach to transform plastic waste into high value-added chemicals to achieve a sustainable circular economy.

关键词： Catalytic polyester catalyst

Exploring the functional roles of small-molecule metabolites in disease research:Recent advancements in metabolomics

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Chinese Chemical Letters 2024年第8期35卷 93-100页

作者： Aolei Tan Xiaoxiao ma Department of Precision Instrument Tsinghua UniversityBeijing 100084China

Metabolism encompasses a series of intricate biochemical processes that are vital for the sustenance of life in ***,an essential scientific discipline,is a field of study within the broader domain of systems biology that focuses on the comprehensive analysis of small molecules,known as metabolites including lipids,coenzymes,etc.,which are synthesized during *** the contin-uous development of metabolomics,the multiple biological functions of metabolites are constantly being discovered,encompassing signal transduction and enzyme stimulation,while concurrently exhibiting as-sociations with afflictions like cancer and *** comprehension of metabolite functionalities and their intricate interplay with disease conditions assumes paramount importance in both disease-focused research endeavors and the development of diagnostic *** scholarly exposition undertakes an ex-tensive review of recent advancements in the investigation of functional roles assumed by metabolites,with specific emphasis on metabolites in lipid synthesis,glucose metabolism and exogenous metabolites.

关键词： Metabolites Small molecules Biological functions Physiological processes Diseases

Partial regularity and nonlinear potential estimates for Stokes systems with super-quadratic growth

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Science China mathematics 2024年第7期67卷 1525-1554页

作者： Lingwei ma Zhenqiu Zhang School of mathematical Sciences Tianjin Normal UniversityTianjin300387China School of mathematical Sciences and LPMC Nankai UniversityTianjin300071China

This paper builds a bridge between partial regularity theory and nonlinear potential theory for the following generalized stationary Stokes system with super-quadratic growth and continuous coefficients:-div A(x,Du)+■π=f,div u=0,where Du is the symmetric part of the gradient■*** first establish anε-regularity criterion involving both the excess functional of the symmetric gradient Du and Wolff potentials of the nonhomogeneous term f to guarantee the local vanishing mean oscillation(VMO)-regularity of Du in an open subset Ω_(u) of Ω with full *** anε-regularity criterion leads to a pointwise Wolff potential estimate of Du,which immediately infers that Du is partially C^(0)-regular under appropriate ***,we give a local continuous modulus estimate of Du.

关键词： nonlinear Stokes system partial regularity Wolff potential estimates continuous modulus estimates

Nuance of inward rectifying potassium(Kir) channel dysfunctions in neurodegenerative diseases

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Neural Regeneration Research 2024年第6期19卷 1195-1196页

作者： Benjamin Garland Linlin ma Griffith Institute for Drug Discovery & School of Environment and Science Griffith University

Neurodegenerative disorders are highly prevalent and diverse in nature. Their manifestation largely depends on the cell types involved, with aberrant inflammatory episodes progressively inducing a constellation of phenotypes that are classified into specific diseases based on their neuropathological traits. The two most prevalent neurodegenerative diseases worldwide,

关键词： K-ATP CHANNELS PARKINSONS-DISEASE MODEL

Time-inconsistent stochastic linear-quadratic control problem with indefinite control weight costs

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Science China mathematics 2024年第1期67卷 211-236页

作者： Qi Lü Bowen ma School of mathematics Sichuan UniversityChengdu 610064China

A time-inconsistent linear-quadratic optimal control problem for stochastic differential equations is *** introduce conditions where the control cost weighting matrix is possibly *** such conditions,we obtain a family of closed-loop equilibrium strategies via multi-person differential *** result extends Yong’s work(2017) in the case of stochastic differential equations,where a unique closed-loop equilibrium strategy can be derived under standard conditions(namely,the control cost weighting matrix is uniformly positive definite,and the other weighting coefficients are positive semidefinite).

关键词： linear-quadratic optimal control problem time-inconsistent cost functional generalized Riccati equation indefinite control weight cost closed-loop equilibrium strategy

Performance Enhancement of XML Parsing Using Regression and Parallelism

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Computer Systems Science & Engineering 2024年第2期48卷 287-303页

作者： Muhammad Ali Minhaj Ahmad khan Department of Computer Science Bahauddin Zakariya UniversityMultan60000Pakistan

The Extensible markup Language(XML)files,widely used for storing and exchanging information on the web require efficient parsing mechanisms to improve the performance of the *** the existing Document Object Model(DOM)based parsing,the performance degrades due to sequential processing and large memory requirements,thereby requiring an efficient XML parser to mitigate these *** this paper,we propose a Parallel XML Tree Generator(PXTG)algorithm for accelerating the parsing of XML files and a Regression-based XML Parsing Framework(RXPF)that analyzes and predicts performance through profiling,regression,and code generation for efficient *** PXTG algorithm is based on dividing the XML file into n parts and producing n trees in *** profiling phase of the RXPF framework produces a dataset by measuring the performance of various parsing models including StAX,SAX,DOM,JDOM,and PXTG on different cores by using multiple file *** regression phase produces the prediction model,based on which the final code for efficient parsing of XML files is produced through the code generation *** RXPF framework has shown a significant improvement in performance varying from 9.54%to 32.34%over other existing models used for parsing XML files.

关键词： Regression parallel parsing multi-cores XML