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集值映射空间上可数强Fan tightness

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杭州师范大学学报（自然科学版） 2010年第1期9卷 23-25,80页

作者：郭先一李祖泉杭州师范大学理学院浙江杭州310036

讨论了连续集值映射空间在赋予紧开拓扑下的可数强fan tightness的等价条件,利用可数开k覆盖列给出了集值映射族Ck(X,R)的可数强fan tightness的刻画,获得了空间X与Ck(X,R)的对偶定理,将单值连续映射空间的某些结果推广到连续集值映射空间.

关键词：集值映射紧开拓扑 k覆盖可数强fan tightness

Theoretical research on gas seepage in the formations surrounding bedded gas storage salt cavern

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Petroleum Science 2022年第4期19卷 1766-1778页

作者： Xiang-Sheng Chen Yin-Ping Li Ya-Long Jiang Yuan-Xi Liu Tao Zhang State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013Jiangxi China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071 HubeiChina University of Chinese Academy of Sciences Beijing 100049China

When constructing salt cavern gas or petroleum storage in lacustrine sedimentary salt formations rich in mudstone interlayers, the influence of the sealing performance of interlayers and salt-mud interface on the storage tightness should be considered adequately. In order to reveal the gas seepage in deep formations surrounding bedded salt cavern underground storage, a leakage analysis model was established based on the characteristics of a low dip angle and the interbedded structure of bedded rock salt. The gas seepage governing equations for one-dimensional and plane radial flow were derived and solved. A gas seepage simulation experiment was conducted to demonstrate the accuracy and reliability of the theoretical calculation results. The error of the seepage range was approximately 6.70%, which is acceptable. The analysis and calculation results indicate that the motion equation of gas in deep formations satisfies a non-Darcy's law with a threshold pressure gradient and slippage effect. The sufficient condition for the gas flow to stop is that the pressure gradient is equal to the threshold pressure gradient.The relationship between the leakage range and operating time is a positive power function, that is, the leakage range gradually increases with time and eventually stabilizes. As the seepage range increases, the seepage pressure decreases sharply during the early stage, and then decreases gradually until the flow stops.Combining the research results with engineering applications, three quantitative evaluation indexes named the maximum admissible leakage range, leakage volume and leakage rate are proposed for the tightness evaluation of gas storage salt cavern during their operating stage. These indexes can be used directly in actual engineering applications and can be compared with the key design parameters stipulated in the relevant specifications. This work is expected to provide theoretical and technical support for the gas loss and tightness evaluation of gas storage salt caverns.

关键词： Gas storage salt cavern Seepage tightness Non-Darcy's law Leakage

Air tightness Control of Passenger Car Wheels

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Engineering（科研） 2017年第2期9卷 171-180页

作者： Vatroslav Grubisic Zum Stetteritz 1 Reinheim-Georgenhausen Germany

Since the tubeless tires and especially cast alloy wheels are used, the air tightness of wheels is an important factor of the automobiles quality. Based on specification of the car industry that up to 10% decrease of the prescribed nominal tire pressure during a time of six-month is allowed, the requirements presented in specifications and norms are treated and validated. The practical experience and influences on the wheel tightness control are discussed and the data presented in a report of a wheel manufacturer, concerning the replacements of wheels in service due to air leakage are evaluated. Summarizing the results of analyses, a proposal is made for the testing of the cast aluminum car wheels to meet the requirements for a reliable and economical air tightness control in modern test facilities.

关键词： Light Alloy Cast Wheels Air tightness Leakage Control Painting Influence Practical Experience

Limits of One-dimensional Interacting Particle Systems with Two-scale Interaction

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Chinese Annals of Mathematics,Series B 2022年第2期43卷 195-208页

作者： Tong ZHAO School of Mathematical Sciences Fudan UniversityShanghai 200433China

This paper characterizes the limits of a large system of interacting particles distributed on the real line.The interaction occurring among neighbors involves two kinds of independent actions with different rates.This system is a generalization of the voter process,of which each particle is of type A or a.Under suitable scaling,the local proportion functions of A particles converge to continuous functions which solve a class of stochastic partial differential equations driven by Fisher-Wright white noise.To obtain the convergence,the tightness of these functions is derived from the moment estimate method.

关键词： Interacting particle systems Stochastic partial differential equations Two-scale interaction tightness

On Uniform Large Deviations Principle for Multi-valued SDEs via the Viscosity Solution Approach

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Chinese Annals of Mathematics,Series B 2019年第2期40卷 285-308页

作者： Jiagang REN Jing WU School of Mathematics Sun Yat-Sen University

This paper deals with the uniform large deviations for multivalued stochastic differential equations(MSDEs for short) by applying a stability result of the viscosity solutions of second order Hamilton-Jacobi-Belleman equations with multivalued operators.Moreover, the large deviation principle is uniform in time and in starting point.

关键词： Multivalued stochastic differential equation Large deviation principle Viscosity solution Exponential tightness Laplace limit

Multi-user security of the tweakable Even-Mansour cipher

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Science China(Information Sciences) 2021年第5期64卷 223-225页

作者： Ping ZHANG Qian YUAN Honggang HU Peng WANG School of Computer Science Nanjing University of Posts and Telecommunications School of Economics and Management Southeast University School of Information Science and Technology University of Science and Technology of China Institute of Information Engineering Chinese Academy of Sciences

Dear editor,Data security, including data privacy security and data integrity security, are usually achieved by a cryptographic algorithm. Block ciphers are widely used to design the cryptographic scheme. However, in some special environments, block ciphers are no longer applicable. A tweakable blockcipher(TBC) is an improved version of a conventional block cipher, which adds an extra input, called tweak,

关键词： symmetric cryptography tweakable blockcipher tweakable Even-Mansour cipher multi-user security tightness (beyond) birthday bound

Assessing the oscillation of channel geometry and meander migration cardinality of Bhagirathi River,West Bengal,India

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Journal of Geographical Sciences 2019年第4期29卷 613-634页

作者： Rakhohori Bag Ismail Mondal Jatisankar Bandyopadhyay Department of Remote Sensing&GIS Vidyasagar UniversityMidnapore-721102India Department of Marine Science University of CalcuttaKolkata-700019India

Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal,India.The Bhagirathi River flows SW for-67.30 km betwee n the confluenee point of Ajay and Jalangi rivers in East Burdwan and Nadia districts of West Bengal.The course of Bhagirathi is notably migration prone and cultivates problematic changes along its course over time.In the study,we have looked into its migration tendency and unpredictability for past 238 years and then predicted the lateral shifting of river centerline using temporal satellite imageries-Landsat-5(TM)of 1987(8,December),1995(28,January),2005(7,January)and LISS-IV satellite imagery(2017,5 January);SOI Toposheet-1968-1969(79A/2,79A/3,79A/6 and 79A/7)and RennelPs map of 1779.Other highlights are the quest of fluvial features,oxbow lakes,mid-channel bars,channel migration rate,meander geometry,channel sinuosity in different parts of river course and the parts that experience intensive bank erosion.The entire river course has been subdivided into three segments;viz.reaches A,B and C.Investigation displays that degree of sinuosity decreases from its anterior course(1968)to the existing course(2017).Reach-specific outputs display that reach B is highly sinuous(SI value 1.94 in 2017)and SI increases temporarily,whereas for reaches A and C it decreases with time.The rate of migration is higher in reach B than that in reaches C and A.The study displays a notably decreasing trend of migration in comparison with its previous lateral migration and shows that the migration nature over time is intensively inconsistent and unpredictable except very few portions of the river course.The nature of deposition within the river channel shows an unstable behavior during the entire period of the study.Meander geometry depicts a rapid change of river course innate to meander bends and shows a higher rate of migration by meander loop cut-off rather than lateral migration that reflects the inconsistency,erosion vulnerability and unpredictable nature of migration.Th

关键词： channel geometry sinuosity index braiding index meander geometry radius of curvature bend tightness index linear regression GIS

Controlled Stochastic Partial Differential Equations for Rabbits on a Grassland

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Acta Mathematicae Applicatae Sinica 2020年第2期36卷 262-282页

作者： Suzanne LENHART Xiao TANG Jie XIONG Jiong-min YONG Department of Mathematics University of TennesseeKnoxvilleTN 37996-1320USA Department of Mathematics.Southern University of Science and Technology Shenzhen518055China Department of Mathematics University of Central FloridaOrlandoFL 32816USA

A new approach to modeling populations incorporating stochasticity,a random environment,and individual behavior is illustrated with a specific example of two interacting populations:rabbits and grass.The derivation of the system of stochastic partial differential equations(SPDEs)to show how the individual mechanisms of both populations are included.This model also has an unusual feature of a nonlocal term.The harvesting of the rabbit population is introduced as a control variable.

关键词： Stochastic partial differential equation tightness optimal control population model

Asymptotic Properties of Integro-differential Systems with Wideband Noise Perturbations

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Asymptotic Properties of Integro-differential Systems with W...