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Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 162-170页

作者： Pei-ming WANG xian-ping LIU Key Laboratory of Advanced Civil Engineering Materials (Tongji University) Ministry of Education Shanghai 201804 China

This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend(ACGC) . Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing. To evaluate the specific effect of activated coal gangue(ACG) as a supplementary cementing material(SCM) ,a fly ash-cement blend(FAC) was used as a control. Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength. The effect of curing temperature on FAC is greater than that on ACGC. The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 °C,but when the curing temperature reaches 60 °C,the changing nature of the pore structure leads to a decrease in strength. The correlation between compressive strength and the degree of hydration and porosity is linear in nature.

关键词： Activated coal gangue (ACG) Fly ash (FA) Blended cement Hydration Curing temperature Strength

Zero-Sum Stochastic Games with Average Payoffs:New Optimality Conditions

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Acta Mathematica Sinica,English Series 2009年第7期25卷 1201-1216页

作者： Jie YANG xian ping GUO School of Science Beijing Information Science and Technology University Beijing 100192 P. R. China School of Mathematics and Computational Science Zhongshan University Guangzhou 510275 P. R. China

In this paper we study zero-sum stochastic games. The optimality criterion is the long-run expected average criterion, and the payoff function may have neither upper nor lower bounds. We give a new set of conditions for the existence of a value and a pair of optimal stationary strategies. Our conditions are slightly weaker than those in the previous literature, and some new sufficient conditions for the existence of a pair of optimal stationary strategies are imposed on the primitive data of the model. Our results are illustrated with a queueing system, for which our conditions are satisfied but some of the conditions in some previous literatures fail to hold.

关键词： zero-sum stochastic games countable state space expected average criterion new condi- tion a pair of optimal stationary strategies

First Passage Models for Denumerable Semi-Markov Decision Processes with Nonnegative Discounted Costs

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Acta Mathematicae Applicatae Sinica 2011年第2期27卷 177-190页

作者： Yong-hui Huang xian-ping Guo School of Mathematics and Computational Science Sun Yat-Sen University Guangzhou 510275 China

This paper considers a first passage model for discounted semi-Markov decision processes with denumerable states and nonnegative costs. The criterion to be optimized is the expected discounted cost incurred during a first passage time to a given target set. We first construct a semi-Markov decision process under a given semi-Markov decision kernel and a policy. Then, we prove that the value function satisfies the optimality equation and there exists an optimal （or ε-optimal） stationary policy under suitable conditions by using a minimum nonnegative solution approach. Further we give some properties of optimal policies. In addition, a value iteration algorithm for computing the value function and optimal policies is developed and an example is given. Finally, it is showed that our model is an extension of the first passage models for both discrete-time and continuous-time Markov decision processes.

关键词： Semi-Markov decision processes target set first passage time discounted cost optimal policy

Construction and Regularity of Transition Functions on Polish Spaces under Measurability Conditions

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Acta Mathematicae Applicatae Sinica 2013年第1期29卷 1-14页

作者： Liu-er Ye xian-ping Guo College of Economics Jinan University School of Mathematics and Computational Science Guangdong Province Key Laboratory of Computational Science Sen-Yat Sen University

This paper concerns the construction and regularity of a transition （probability） function of a nonhomogeneous continuous-time Maxkov process with given transition rates and a general state space. Motivating from a lot of restriction in applications of a transition function with continuous （in t ≥0） and consewative transition rates q（t, x, A）, we consider the case that q（t, x, A） axe only required to satisfy a mild measurability （in t ≥ O） condition, which is a generalization of the continuity condition. Under the measurability condition we construct a transition function with the given transition rates, provide a necessary and sufficient condition for it to be regular, and further obtain some interesting additional results.

关键词： Transition rate transition function construction and regularity measurability condition

Hydration process in Portland cement blended with activated coal gangue

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第7期12卷 503-510页

作者： xian-ping LIU Pei-ming WANG Min-ju DING Key Laboratory of Advanced Civil Engineering Materials (Tong/i University) Ministry of Education Shanghai 201804 China State Key Laboratory Breeding Base of Crime Scene Evidence Shanghai 200083 China

This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength *** hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-evaporable water measurement,and X-ray diffraction *** results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement *** pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate *** hydrates are similar to those found in pure Portland *** results show that if activated coal gangue is substituted for cement at up to 30%(w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a sup-plementary cementing *** relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same ***,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.

关键词： Activated coal gangue Portland cement Blended cement Hydration Strength

First Passage Risk Probability Minimization for Piecewise Deterministic Markov Decision Processes

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Acta Mathematicae Applicatae Sinica 2022年第3期38卷 549-567页

作者： Xin WEN Hai-feng HUO xian-ping GUO School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China Guangdong Province Key Laboratory of Computational Science Sun Yat-sen UniversityGuangzhou 510275China School of Science Guangxi University of Science and TechnologyLiuzhou 545006China

This paper is an attempt to study the minimization problem of the risk probability of piecewise deterministic Markov decision processes(PDMDPs)with unbounded transition rates and Borel *** from the expected discounted and average criteria in the existing literature,we consider the risk probability that the total rewards produced by a system do not exceed a prescribed goal during a first passage time to some target set,and aim to find a policy that minimizes the risk probability over the class of all history-dependent *** suitable conditions,we derive the optimality equation(OE)for the probability criterion,prove that the value function of the minimization problem is the unique solution to the OE,and establish the existence ofε(≥0)-optimal ***,we provide two examples to illustrate our results.

关键词： piecewise deterministic Markov decision processes risk probability first passage time ε-optimal policy

Generation of Multi-ion Graph States with Trapped Ions in Thermal Motion

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Communications in Theoretical Physics 2008年第9期50卷 640-642页

作者： WANG xian-ping DONG ping YANG Ming CAO Zhuo-Liang Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education School of Physics and Material Science Anhui University Hefei 230039 China Department of Physics Hefei Teachers College Hefei 230061 China

We propose a scheme for generating multi-ion graph states using many trapped ions in thermal *** generation scheme is insensitive to external state since the interaction between ions and laser fields does not involvet... 详细信息

关键词： multi-ion graph state trapped-ion system thermal motion

Optimal Stopping Time of a Portfolio Selection Problem with Multi-assets

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Journal of the Operations Research Society of China 2021年第1期9卷 163-179页

作者： xian-ping Wu Seakweng Vong Wen-Xin Zhou School of Applied Mathematics Guangdong University of TechnologyGuangzhou 510006China Department of Mathematics University of MacaoMacaoChina Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina

In this work,we study a right time for an investor to stop the investment among multi-assets over a given investment horizon so as to obtainmaximum *** formulate it to a two-stage *** main problem is not a standard optimal stopping problem due to the non-adapted term in the objective function,and we turn it to a standard one by stochastic *** subproblem with control variable in the drift and volatility terms is solved first via stochastic control method.A numerical example is presented to illustrate the efficiency of the theoretical results.

关键词： Optimal stopping Portfolio Valuefunction Dynamic programming Holding region

Blinking adaptation for synchronizing a mobile agent network

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 658-666页

作者： Huan SHI Hua-ping DAI You-xian SUN State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou 310027 China

We investigate the issue of synchronizing a blinking coupling mobile agent network through a blinking adaptation strategy,where each agent with blinking wave emission behavior not only adjusts its blinking period according to the local property of its neighbors,but also coordinates its blinking phase with those of neighboring *** leading the agents to blink orderly with a blinking period commensurate with the characteristic time of the dynamical oscillator,the presented blinking adaptation strategy works effectively in guaranteeing the synchronous motion of the considered network when the power density is *** addition,the influence of the controlling parameter and moving velocity on network evolution is studied by assessing the convergence time.

关键词： Mobile agents Blinking adaptation Coupled-oscillator networks Synchronization