检索结果-南通市图书馆

Superlinearly Convergent Affine Scaling Interior Trust-Region Method for Linear Constrained LC^1 Minimization

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2008年第12期24卷 2081-2100页

作者： De tong zhu Business College Shanghai Normal University Shanghai 200234 P. R. China

We extend the classical affine scaling interior trust region algorithm for the linear constrained smooth minimization problem to the nonsmooth case where the gradient of objective function is only locally Lipschitzian. We propose and analyze a new affine scaling trust-region method in association with nonmonotonic interior backtracking line search technique for solving the linear constrained LC1 optimization where the second-order derivative of the objective function is explicitly required to be locally Lipschitzian. The general trust region subproblem in the proposed algorithm is defined by minimizing an augmented affine scaling quadratic model which requires both first and second order information of the objective function subject only to an affine scaling ellipsoidal constraint in a null subspace of the augmented equality constraints. The global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions where twice smoothness of the objective function is not required. Applications of the algorithm to some nonsmooth optimization problems are discussed.

关键词： trust region method backtracking nonmonotonic technique interior point LC^1 minimization affine scaling

Superlinear Convergence of Affine Scaling Interior Point Newton Method for Linear Inequality Constrained Minimization without Strict Complementarity

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2009年第2期25卷 183-194页

作者： De-tong zhu Business College Shanghai Normal University Shanghai 200234 China

In this paper we extend and improve the classical affine scaling interior-point Newton method for solving nonlinear optimization subject to linear inequality constraints in the absence of the strict complementarity assumption. Introducing a computationally efficient technique and employing an identification function for the definition of the new affine scaling matrix, we propose and analyze a new affine scaling interior-point Newton method which improves the Coleman and Li affine sealing matrix in [2] for solving the linear inequlity constrained optimization. Local superlinear and quadratical convergence of the proposed algorithm is established under the strong second order sufficiency condition without assuming strict complementarity of the solution.

关键词： Interior method affine scaling strict complementarity

Pressure Analysis of the Initial Process of Diffusion Combustion Surge in a 350 kW Gas Boiler

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第2期31卷 582-589页

作者： GAO Han zhu tong PAN Deng School of Mechanical Engineering Tongji UniversityShanghai 201804China

In order to meet the increasingly stringent requirements for nitrogen oxides(NOx)emissions from gas boilers,flue gas recirculation(FGR)technology is commonly used to achieve ultra-low NOx ***,under some ultra-low NOx combustion conditions with FGR,a surge phenomenon occurs in the boiler,which causes a flameout and should be *** this study,the diffusion combustion surge of gas boiler with a rated power of 350 k W and equipped with FGR device was *** characteristic analysis results of the initial process of combustion surge showed that the high-frequency component of pressure is closely related to combustion stability and its change can provide reference for the occurrence of ***,the initial process of surge was analyzed by wavelet packet entropy *** indicated that the wavelet packet entropy of pressure signals could effectively reflect the stability of combustion in the furnace,and it could also be used to study the occurrence of surge.

关键词： diffusion combustion flue gas recirculation wavelet packet entropy surge gas boiler

Heterogeneous reactions of gaseous methanesulfonic acid with NaCl and sea salt particles

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2009年第1期52卷 93-100页

作者： TANG MingJin zhu tong College of Environment Sciences and Engineering Peking UniversityBeijing 100871China

Methanesulfonic acid(MSA) has been identified as one of the most important intermediate products of DMS reactions in the *** considerable amounts of MSA have been found in the ma-rine boundary layer,little is known about the interaction of gaseous MSA with sea salt *** understand the fate of MSA in the atmosphere and its potential importance in atmospheric chemistry,the heterogeneous reactions of gaseous MSA with micron-scale NaCl and sea salt particles were studied using diffuse reflectance infrared Fourier transform spectrometry,X-ray photoelectron spectroscopy,and scanning electron *** CH3SO3Na and CH3SO3-were the major products of the condensed phase of the reaction of gaseous MSA with NaCl and with sea salt *** steady-state uptake coefficient was determined to be(5.94±2.32)×10-7(1 σ) for the reaction of gaseous MSA with NaCl particles and(2.23±1.25)×10-7(1 σ) for the reaction of gaseous MSA with sea salt *** heterogeneous reaction of MSA with NaCl particles was found to be first-order for *** reaction mechanisms were discussed.

关键词： methanesulfonic acid heterogeneous reaction NaCl sea salt

Enhance d thermal-assiste d photocatalytic CO_(2) reduction by RGO/H-CN two-dimensional heterojunction

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第9期176卷 36-47页

作者： Yuhan Liu Jing Shang tong zhu SKL-ESPC and SEPKL-AERM College of Environmental Sciences and Engineeringand Center for Environment and SciencePeking UniversityBeijing 100871P.R.China

Carbon dioxide(CO_(2))can be reduced to high-value fuels using the photocatalysis(PC)technique,which holds immense potential for tackling environmental issues and energy *** construction of metalfree photocatalyst capable of utilizing infrared light to execute thermal-assisted photocatalysis(TPC)remains a *** this study,reduced graphene oxide(RGO)with full-spectrum absorption was used as a thermal-assisted photocatalyst in CO_(2) *** exhibited higher CO_(2) reduction efficiency under the visible and infrared irradiation than the sole visible ***-5(GO treated at 120℃ for 5 h)presented the highest defect density and C-OH/C-O-C content,leading to the best PC and TPC *** was further engineered with HCl protonated g-C_(3)N_(4)(H-CN) to obtain two-dimensional heterojunction RGO/H-CN,which demonstrated the S-scheme charge transfer *** to the synergistic effect of heterojunction and thermal assistance,RGO/H-CN exhibited better CO_(2) reduction efficiencies in both PC and TPC than *** largest yields of CO and CH4 were achieved in 15%RGO/*** research provides new insights for applying RGO as thermal-assisted heterojunction photocatalyst for efficient CO_(2) reduction.

关键词： CO_(2) reduction Thermal-assisted photocatalysis Heterojunction Reduced graphene oxide g-C_(3)N_(4)

Optimization of Operation Strategies for a Combined Cooling, Heating and Power System based on Adiabatic Compressed Air Energy Storage

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第5期29卷 1135-1148页

作者： CHEN Shang zhu tong GAN Zhongxue zhu Xiaojun LIU Liuchen School of Mechanical and Energy Engineering Tongji UniversityShanghai 201804China ENN Science and Technology Development Co. Ltd.Langfang 065000China

The fluctuations of renewable energy and various energy demands are crucial issues for the optimal design and operation of combined cooling,heating and power(CCHP)*** this paper,a novel CCHP system is simulated with advanced adiabatic compressed air energy storage(AA-CAES)technology as a join to connect with wind energy generation and an internal-combustion engine(ICE).The capital cost of utilities,energy cost,environmental protection cost and primary energy savings ratio(P E S R)are used as system performance *** fulfill the cooling,heating and power requirements of a district and consider the thermal-electric coupling of ICE and AA-CAES in CCHP system,three operation strategies are established to schedule the dispatch of AA-CAES and ICE:ICE priority operation strategy,CAES priority operation strategy and simultaneous operation *** strategy leads the operation load of AA-CAES or ICE to improve the energy supply efficiency of the ***,to minimize comprehensive costs and maximize the P E S R,a novel optimization algorithm based on intelligent updating multi-objective differential evolution(MODE)is proposed to solve the optimization *** the multi-interface characteristic and active management ability of the ICE and AA-CAES,the economic benefits and energy efficiency of the three operation strategies are compared by the simulation with the same system *** a typical summer day,the simultaneous strategy is the best solution as the total cost is 3643 USD and the P E S R is 66.1%,while on a typical winter day,the ICE priority strategy is the best solution as the total cost is 4529 USD and the P E S R is 64.4%.The proposed methodology provides the CCHP based AA-CAES system with a better optimized operation.

关键词： combined cooling heating and power(CCHP)system advanced adiabatic compressed air energy storage(AA-CAES) optimization

The Impact of the Storm-Induced SST Cooling on Hurricane Intensity

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2006年第1期23卷 14-22页

作者： tong zhu Da-Lin ZHANG CIRA/CSU at NOAA/NESDIS/ORA Camp Springs MD 20746 USA Department of Meteorology University of Maryland College Park MD 20742 USA

The effects of storm-induced sea surface temperature （SST） cooling on hurricane intensity are investigated using a 5-day cloud-resolving simulation of Hurricane Bonnie （1998）. Two sensitivity simulations are performed in which the storm-induced cooling is either ignored or shifted close to the modeled storm track. Results show marked sensitivity of the model-simulated storm intensity to the magnitude and relative position with respect to the hurricane track. It is shown that incorporation of the storm-induced cooling, with an average value of 1.3℃, causes a 25-hPa weakening of the hurricane, which is about 20 hPa per 1℃ change in SST. Shifting the SST cooling close to the storm track generates the weakest storm, accounting for about 47% reduction in the storm intensity. It is found that the storm intensity changes are well correlated with the air-sea temperature difference. The results have important implications for the use of coupled hurricane-ocean models for numerical prediction of tropical cyclones.

关键词： SST feedback hurricane intensity numerical modeling

Global and Local Convergence of a New Affine Scaling Trust Region Algorithm for Linearly Constrained Optimization

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2016年第10期32卷 1203-1213页

作者： Chao GU De tong zhu School of Mathematics and Information Shanghai LiXin University of Commerce Department of Mathematics Shanghai Normal University

Chen and Zhang [Sci. China, Set. A, 45, 1390-1397 （2002）] introduced an affine scaling trust region algorithm for linearly constrained optimization and analyzed its global convergence. In this paper, we derive a new affine scaling trust region algorithm with dwindling filter for linearly constrained optimization. Different from Chen and Zhang＇s work, the trial points generated by the new algorithm axe accepted if they improve the objective function or improve the first order necessary optimality conditions. Under mild conditions, we discuss both the global and local convergence of the new algorithm. Preliminary numerical results are reported.

关键词： Linearly constrained optimization affine scaling trust region dwindling filter~ conver-gence

Influence of Fill Point in Multiple-Heat-Sources Looped District Heating System with Distributed Variable-Speed Pumps

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第5期29卷 1206-1222页

作者： XU tong YAN Jing WANG Xinlei WANG Hai zhu tong WANG Haiying Beijing Huajian Power Design and Research Institute Beijing 101400China School of Mechanical Enginecring Tongji UniversityShanghai 200092China

When regulating a pipe network according to user demand,hydraulic balance and power consumption are crucial factors for a multi-source looped-pipe network applying distributed variable-speed pumps compared to the conventional central circulating pump *** this paper,the influence of the fill point on power consumption and hydraulic balance of the multi-source looped-pipe network was studied.A mathematical model for electricity energy consumption analysis was built and calculated for a large sized looped-pipe network with multiple heat sources and distributed variable-speed *** hydraulic calculation models of each single element,such as pipe,distribution pump,valve,replenishment pump,heat source and substation,were built.A case located in Dezhou city,China was *** results showed that:the maximum power saving(39.2%)could be achieved when each heat source had its own fill point,but the heat sources would not meet their design flows;to meet the design flows of all the heat sources,only one fill point should be necessarily located near the heat source with the lowest flow rate to get the expected hydraulic stability and energy saving.

关键词： district heating central circulating pump distributed variable-speed pumps fill point energy saving