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Synthesis of Nanosized NaY Zeolite by Confined Space Method 被引量:18
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作者 BoWANG HongZhuMA 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第4期385-388,共4页
Nanosized NaY crystals have been prepared from metakaolin and sodium silicate by confined space synthesis with starch additive. It is found that the product has a narrow crystal size distribution (50-100 nm), high Si... Nanosized NaY crystals have been prepared from metakaolin and sodium silicate by confined space synthesis with starch additive. It is found that the product has a narrow crystal size distribution (50-100 nm), high Si/Al ratio (Si/Al=4.6-6.1), high surface area (1090 m2/g) and the average diameter of nanosized NaY (75 nm) synthesized is 30 nm, it is smaller than that of without starch additive. 展开更多
关键词 Confined space synthesis ZEOLITE nanosized NaY CRYSTALS metakaolin.
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Numerical simulation of detonation of an explosive atmosphere of liquefied petroleum gas in a confined space 被引量:4
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作者 Niculae Serban COSTIN 《Defence Technology(防务技术)》 SCIE EI CAS 2014年第3期294-297,共4页
The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.
关键词 Liquefied petroleum gas OVERPRESSURE CONFINED space Explosion LIMIT
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Modeling and analysis of a catastrophic oil spill and vapor cloud explosion in a confined space upon oil pipeline leaking 被引量:2
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作者 Shengzhu Zhang Xu Wang +1 位作者 Y.Frank Cheng Jian Shuai 《Petroleum Science》 SCIE CAS CSCD 2020年第2期556-566,共11页
Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explo... Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit. 展开更多
关键词 PIPELINE leaking Oil SPILL Vapor CLOUD explosion CONFINED space CONSEQUENCE analysis
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Analysis of temporal and spatial distribution characteristics of ammonium chloride smoke particles in confined spaces 被引量:4
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作者 Chen-youshi Xu Bing-ting Zha +2 位作者 Jia-qian Bao He Zhang Hong-xia Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第7期1269-1280,共12页
In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investi... In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent.The particle size distribution,composition,and mass flow distribution of the smoke were studied.Based on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space.The temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was summarized.Combined with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread around.Meanwhile,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and stable.In the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick.The concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short time.Therefore,this system was suitable for conducting experimental research on laser fuzes in a smoke environment.Owing to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent.Overall,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments. 展开更多
关键词 Laser fuze Smoke environment Temporal distribution Spatial distribution Confined space Smoke agent
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THE SPACE-TIME FINITE ELEMENT METHOD FOR PARABOLIC PROBLEMS 被引量:5
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作者 LI Hong(李宏) +1 位作者 LIU Ru-xun(刘儒勋) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第6期687-700,共14页
Adaptive space-time finite element method, continuous in space but discontinuous in time for semi-linear parabolic problems is discussed. The approach is based on a combination of finite element and finite difference ... Adaptive space-time finite element method, continuous in space but discontinuous in time for semi-linear parabolic problems is discussed. The approach is based on a combination of finite element and finite difference techniques. The existence and uniqueness of the weak solution are proved without any assumptions on choice of the spacetime meshes. Basic error estimates in L-infinity (L-2) norm, that is maximum-norm in time, L-2-norm in space are obtained. The numerical results are given in the last part and the analysis between theoretic and experimental results are obtained. 展开更多
关键词 semi-linear parabolic equations space-time finite element method existence and uniquess error estimate
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Compressed wormlike chain moving out of confined space: A model of DNA ejection from bacteriophage 被引量:2
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作者 Ji-Zeng Wang Long Li Hua-Jian Gao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第4期1219-1226,共8页
The molecular biomechanics of DNA ejection from bacteriophage is of interest to not only fundamental biological understandings but also practical applications such as the design of advanced site-specific and controlla... The molecular biomechanics of DNA ejection from bacteriophage is of interest to not only fundamental biological understandings but also practical applications such as the design of advanced site-specific and controllable drug delivery systems. In this paper, we analyze the viscous motion of a semiflexible polymer chain coming out of a strongly confined space as a model to investigate the effects of various structure confinements and frictional resistances encountered during the DNA ejection process. The theoretically predicted relations between the ejection speed, ejection time, ejection length, and other physical parameters, such as the phage type, total genome length and ionic state of external buffer solutions, show excellent agreement with in vitro experimental observations in the literature. 展开更多
关键词 DNA ejection Bacteriophage. Wormlike chain model Confined semi-flexible polymer. Drag coefficient
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COMMON FIXED POINT OF GENERALIZED WEAKLY CONTRACTIVE MAPS IN PARTIAL METRIC SPACES 被引量:5
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作者 Vesna COJBAIC RAJIC Stojan RADENOVIC Sunny CHAUHAN 《Acta Mathematica Scientia》 SCIE CSCD 2014年第4期1345-1356,共12页
In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, ext... In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, extend, unify, enrich and complement many existing results in the literature. Example are given showing the validaty of our results. 展开更多
关键词 Common fixed point lower semi-continuous function weak (ψ Ф)-contraction partial metric space
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CONTINUITY OF GENERALIZED INVERSES OF LINEAR OPERATORS IN BANACH SPACES AND ITS APPLICATIONS 被引量:1
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作者 黄强联 马吉溥 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第12期1657-1663,共7页
The perturbation problem of generalized inverse is studied. And some new stability characteristics of generalized inverses were presented. It was also proved that the stability characteristics of generalized inverses ... The perturbation problem of generalized inverse is studied. And some new stability characteristics of generalized inverses were presented. It was also proved that the stability characteristics of generalized inverses were independent of the choice of the generalized inverse. Based on this result, two sufficient and necessary conditions for the lower semi-continuity of generalized inverses as the set-valued mappings are given. 展开更多
关键词 generalized inverse Moore-Penrose inverse lower semi-continuity Banach space
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Separation of Oil Phase from Dilute Oil/Water Emulsion in Confined Space Apparatus
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作者 王硕 秦炜 戴猷元 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第2期239-245,共7页
A miniature process for separating the oil phase from dilute oil/water emulsion is developed.This process applies a confined space apparatus,which is a thin flow channel made of two parallel plastic plates.The space b... A miniature process for separating the oil phase from dilute oil/water emulsion is developed.This process applies a confined space apparatus,which is a thin flow channel made of two parallel plastic plates.The space between the two plates is rather narrow to improve the collisions between oil droplets and the plate surface.Oil droplets have an affinity for the plate surface and thus are captured,and then coalesce onto the surface.The droplet size distribution of the residual emulsion resulted from the separation process is remarkably changed.The oil layer on the plate weakens the further separation of oil droplets from the emulsion.Three types of plate materials,polypropylene(PP),polytetrafluoroethylene(PTFE) and nylon 66,were used.It is found that PP is the best in terms of the oil separation efficiency and nylon 66 is the poorest.The interaction between droplets in the emulsion and plate surface is indicated by the spreading coefficient of oil droplet on the plate in aqueous environment,and the influences of formed oil layer and plate material on the separation efficiency are discussed. 展开更多
关键词 oil/water emulsion confined space apparatus oil separation efficiency spreading coefficient
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Strong convergence theorems for nonexpansive semi-groups in Banach spaces 被引量:2
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作者 张石生 杨莉 柳京爱 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第10期1287-1297,共11页
Some strong convergence theorems of explicit composite iteration scheme for nonexpansive semi-groups in the framework of Banach spaces are established. Results presented in the paper not only extend and improve the co... Some strong convergence theorems of explicit composite iteration scheme for nonexpansive semi-groups in the framework of Banach spaces are established. Results presented in the paper not only extend and improve the corresponding results of ShiojiTakahashi, Suzuki, Xu and Aleyner-Reich, but also give a partially affirmative answer to the open questions raised by Suzuki and Xu. 展开更多
关键词 nonexpansive semi-group demi-closed principle common fixed point uni-formly smooth Banach space weakly continuous normalized duality mapping
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Water Molecules in the Carbon C60 Confined Space
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作者 M. Baskar N. Sathyan T. R. Gopalakrishnan Nair 《Journal of Biophysical Chemistry》 2018年第2期15-21,共7页
Experimental scenario of the world being successful in planting water molecule at binary level in fullerene C70 is of utmost importance to pursue the theoretical properties of predictive triple water molecules and pol... Experimental scenario of the world being successful in planting water molecule at binary level in fullerene C70 is of utmost importance to pursue the theoretical properties of predictive triple water molecules and poly water molecules in Vander Waals confined space like fullerenes. Here, we present a paper in these lines of exploration of embedding triple water molecules in a Carbon confined space through the studies of behavior of three water molecules in Fullerene C60 by ab-initio methods. This heterogeneous system manifests cyclic hydrogen bonds which may be working with flipping actions. The unusual structural property of water trimers is reported. There exists a dipole moment of 0.9 ± 0.1 Debye which indicates the probable semiconductor properties. 展开更多
关键词 Endohedral FULLERENE C60 Ab-Initio Water TRIMER CARBON CONFINED space DIPOLE
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On Irresolute Topological Vector Spaces
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作者 Moizud Din Khan Muhammad Asad Iqbal 《Advances in Pure Mathematics》 2016年第2期105-112,共8页
In this paper, our focus is to investigate the notion of irresolute topological vector spaces. Irresolute topological vector spaces are defined by using semi open sets and irresolute mappings. The notion of irresolute... In this paper, our focus is to investigate the notion of irresolute topological vector spaces. Irresolute topological vector spaces are defined by using semi open sets and irresolute mappings. The notion of irresolute topological vector spaces is analog to the notion of topological vector spaces, but mathematically it behaves differently. An example is given to show that an irresolute topological vector space is not a topological vector space. It is proved that: 1) Irresolute topological vector spaces possess open hereditary property;2) A homomorphism of irresolute topological vector spaces is irresolute if and only if it is irresolute at identity element;3) In irresolute topological vector spaces, the scalar multiple of semi compact set is semi compact;4) In irresolute topological vector spaces, every semi open set is translationally invariant. 展开更多
关键词 Topological Vector space Irresolute Topological Vector space Irresolue Mapping Semi Open Set
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Accidents during Tanker Accident in Confined Spaces
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作者 Omar Mohamed Fouad Farid 《Journal of Shipping and Ocean Engineering》 2017年第5期203-209,共7页
One of the major hazards when working onboard Tankers is working in confined spaces, improving the procedures in working in such spaces is obvious, but developing the equipments used in rescue operation is rare to hap... One of the major hazards when working onboard Tankers is working in confined spaces, improving the procedures in working in such spaces is obvious, but developing the equipments used in rescue operation is rare to happen, that's why this paper is focusing on differentiating between the manual & more developed equipments used specially in rescuing the crew in such an adequate time, to save the workers' life. The manual way is called "MUCKY CRANE" which is used for rescue purposes onboard tankers, in any of the confined spaces, should be replaced by excel crane which is air or hydraulic driven machine, to achieve better results. As safety precautions measures taken in such tasks are not enough for the required objective achievement. Such safety procedures have been discussed and critical situations have been pointed out. 展开更多
关键词 Hazards tankers confined spaces equipment development rescue operations mucky crane excel crane safetyprecautions measures critical situations.
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More Properties of Semi-Linear Uniform Spaces
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作者 S. A. Alhihi 《Applied Mathematics》 2015年第6期1069-1075,共7页
In this paper we shall generalize the definition given in [1] for Lipschitz condition and contractions for functions on a non-metrizable space, besides we shall give more properties of semi-linear uniform spaces.
关键词 LIPSCHITZ Condition CONTRACTIONS Not METRIZABLE spaceS SEMI-LINEAR spaceS UNIFORM spaceS Fixed Point
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Constant modulus semi-blind space-time equalizer based on structure risk minimum criterion
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作者 毛忠阳 王红星 +1 位作者 宋恒 李军 《Journal of Beijing Institute of Technology》 EI CAS 2013年第4期536-543,共8页
A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) crit... A new adaptive filtering principle based on capability control and semi-blind method is presented. A new semi-blind space-time equalizer based on constant modulus characteristic and structure risk minimum (SRM) criterion is also proposed. The equalizer sufficiently exploits the learning information of communication signals by using the structure information of filter itself through capability control technique. Namely, it maximizes the amount of learning information to im- prove filter tracking performance. Simulations are carried out and the result is compared with that of typical recursive least squares space-time equalizer (RLS-STE) and constant modulus semi-blind space-time equalizer ( CM-SB-STE ). The results show that, even if with insufficient training data, the SRM constant modulus semi-blind space-time equalizer (SCM-SB-STE) keeps good tracking per- formance, showing promises in mobile wireless communications. 展开更多
关键词 EQUALIZATION space-time filter capability control SEMI-BLIND constant modulus
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多分隔受限场景空间火灾疏散安全性分析 被引量:1
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作者 李华 孙林霞 益朋 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第5期107-114,共8页
为了优化密室逃脱类场所的复杂空间布局,基于该场所剧情场景下空间多重分隔、空间狭小、封闭且组合多样等结构特点,分析归纳该场所3种典型的受限场景空间类型,以西安市某密室逃脱类场所建筑布局为例,运用Pathfinder和PyroSim软件对其展... 为了优化密室逃脱类场所的复杂空间布局,基于该场所剧情场景下空间多重分隔、空间狭小、封闭且组合多样等结构特点,分析归纳该场所3种典型的受限场景空间类型,以西安市某密室逃脱类场所建筑布局为例,运用Pathfinder和PyroSim软件对其展开火灾情景下的疏散模拟仿真,进而对比分析不同场景空间的火灾特性指标以及疏散安全性。研究结果表明:密室逃脱类场所3种场景空间中,串联式场景空间人员疏散时间最长(141.53 s),单元式次之(115.53 s),并联式最短(112.28 s);从火灾烟气模拟结果看,串联式场景空间安全出口的温度、CO体积分数以及能见度始终都处于安全临界范围内,而其他2种场景空间均超过临界值,并且能见度降至0.06 m,因此从安全性判定,该密室逃脱类场所只有串联式场景空间人员疏散过程是安全的,并联式和单元式场景空间人员疏散过程中均存在一定危险性。对于密室逃脱类场所这种特定狭小空间,烟气的危害对人员安全疏散的影响尤为显著,因此要在防排烟和火灾荷载方面进行重点防控。研究结果可为密室逃脱类场所的空间结构优化提供消防指导。 展开更多
关键词 密室逃脱类场所 火灾疏散 受限场景空间 多分隔 仿真模拟
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COVERING PROPERTIES ON H-SPACES AND APPLICATIONS
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作者 丁协平 陈国强 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1993年第12期1079-1088,共10页
Several theorems on closed (resp. open) covering properties of H-spaces are obtained which improve and generalize the corresponding results of Sperner, Klee, Alexandroff-Pasynkoff, Berge, Ghouila-Houri, Danzer-Grunbau... Several theorems on closed (resp. open) covering properties of H-spaces are obtained which improve and generalize the corresponding results of Sperner, Klee, Alexandroff-Pasynkoff, Berge, Ghouila-Houri, Danzer-Grunbaum-Klee, Ky Fan, Shih-Tan, Horvath and Lassonde. As application an almost fixed point theorem for lower semi-continuous map in l.c.-spaces and a generalization of Tychonoffs fixed point theorem are proved in l.c.-spaces which improve those results of Ky Fan and Horvath. 展开更多
关键词 covering property H-space H-convex H-convex hull almost fixed point lower semi-continuous l.c.-space SIMPLEX uniform structure topological vector space locally convex space contractible
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COMPLETE SPACE-LIKE SUBMANIFOLDS IN LOCALLY SYMMETRIC SEMI-DEFINITE SPACES
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作者 XuSenlin ChenDongmei 《Analysis in Theory and Applications》 2004年第4期383-390,共8页
The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We firs... The purpose of this paper is to study complete space-like submanifolds with parallel mean curvature vector and flat normal bundle in a locally symmetric semi-defnite space satisfying some curvature conditions. We first give an optimal estimate of the Laplacian of the squared norm of the second fundamental form for such submanifold. Furthermore, the totally umbilical submanifolds are characterized. 展开更多
关键词 space-like submanifolds constant mean curvature flat normal bundle second fundamental form locally symmetric semi-definite space
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Psychological Issues in Simulated Space Missions:What We Learn From Chinese Crew
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作者 WU Ruilin MA Qianying 《Aerospace China》 2022年第4期35-44,共10页
Inspired by the mysteries of the universe,humans have been exploring outer space since the 1950s.Proceeding from I-day(Shenzhou 5)to 6-month(Shenzhou 15)missions,one of the perspectives of Chinese space exploration ha... Inspired by the mysteries of the universe,humans have been exploring outer space since the 1950s.Proceeding from I-day(Shenzhou 5)to 6-month(Shenzhou 15)missions,one of the perspectives of Chinese space exploration has shifted from not just how to safely survive but to how to healthily live in outer space.In current review,we introduce some common psychological stressors during space missions and how researchers simulate these stressors on the ground firstly.Then,we briefly introduce classic and state-of-the-art measurements and tools used in measuring the mental state of crew members.Self-reporting questionnaires,behavioral observations,and computerized tests are widely used as measurement strategies in this field.We discuss,respectively,how challenging missions negatively and positively affect crew members.As psychological issues are sensitive to individual and cultural backgrounds,we focus on Chinese crew members and potential cultural differences.Finally,we propose some potential future directions this research could evolve based on previous findings. 展开更多
关键词 space psychology isolated and confined environment extreme environment positive psychology
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NONLINEAR SEMIGROUPS AND DIFFERENTIAL INCLUSIONSIN PROBABILISTIC NORMED SPACES
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作者 张石生 陈玉清 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第9期815-829,共15页
The purpose of this paper is to introduce and study the semi-groups of nonlinear contractions in probabilistic normed spaces and to establish the Crandall-Liggett's exponential formula for some kind of accretive m... The purpose of this paper is to introduce and study the semi-groups of nonlinear contractions in probabilistic normed spaces and to establish the Crandall-Liggett's exponential formula for some kind of accretive mappings in probabilistic normed spaces. As applications, these results are utilized to study the Cauchy problem for a kind of differential inclusions with accretive mappings in probabilistic normed spaces. 展开更多
关键词 semigroup of nonlinear contractions probabilistic normed space Crandall-Liggett's exponential formula semi-inner product accretive mappings
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