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Ensuring water security by utilizing roof-harvested rainwater and lake water treated with a low-cost integrated adsorption-filtration system

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Water Science and Engineering 2017年第2期10卷 115-124页

作者： Riffat Shaheed wan Hanna Melini wan Mohtar Ahmed El-Shafie Department of Civil and Structural Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan MalaysiaBandar Baru Bangi 43600 Malaysia

Drinking water is supplied through a centralized water supply system and may not be accessed by communities in rural areas of *** study investigated the performance of a low-cost, self-prepared combined activated carbon and sand filtration(CACSF) system for roofharvested rainwater and lake water for potable use. Activated carbon was self-prepared using locally sourced coconut shell and was activated using commonly available salt rather than a high-tech procedure that requires a chemical reagent. The filtration chamber was comprised of local,readily available sand. The experiments were conducted with varying antecedent dry intervals(ADIs) of up to 15 d and lake water with varying initial chemical oxygen demand(COD) concentration. The CACSF system managed to produce effluents complying with the drinking water standards for the parameters p H, dissolved oxygen(DO), biochemical oxygen demand(BOD5), COD, total suspended solids(TSS), and ammonia nitrogen(NH_3-N). The CACSF system successfully decreased the population of Escherichia coli(E. coli) in the influents to less than 30 CFU/m L. Samples with a higher population of E. coli(that is, greater than 30 CFU/m L) did not show 100% removal. The system also showed high potential as an alternative for treated drinking water for roof-harvested rainwater and class II lake water.

关键词： Low-cost activated carbon Integrated adsorption-sand filtration Roof-harvested rainwater Lake water Water security

Synthesis and Rheological Investigation of Model Symmetric 3-Arm Star Polyethylene

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Chinese Journal of Polymer Science 2014年第1期32卷 51-63页

作者： Feng Liu Dong wan 唐涛 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences Graduate School of the Chinese Academy of Sciences

A variety of linear and 3-arm star polyethylene （PE） model polymers covering a wide range of molecular weight are synthesized by the living polymerization of butadiene and the subsequent hydrogenation. Several rheological parameters of these model linear and 3-arm star PE samples are analyzed for detecting the long chain branching （LCB） structure. It is found that the analyses based on zero shear viscosity, vGP plot and flow activation energy are very sensitive to the 3-arm star PEs. The information on the presence of LCB can be obtained with these methods even for low molecular weight samples, which can not be determined by GPC-MALLS. However the information about the LCB structure can not be obtained by the rheological methods alone.

关键词： Long chain branching Rheology Star polymers Polyethylene Thermorheology.

Numerical Modeling of a Spherical Buoy Moored by a Cable in Three Dimensions

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 588-597页

作者： ZHU Xiangqian YOO wan-Suk Computer Aided Engineering Laboratory School of Mechanical Engineering Pusan National University

Floating facilities have been studied based on the static analysis of mooring cables over the past decades. To analyze the floating system of a spherical buoy moored by a cable with a higher accuracy than before, the dynamics of the cables are considered in the construction of the numerical modeling. The cable modeling is established based on a new element frame through which the hydrodynamic loads are expressed efficiently. The accuracy of the cable modeling is verified with an experiment that is conducted by a catenary chain moving in a water tank. In addition, the modeling of a spherical buoy is established with respect to a spherical coordinate in three dimensions, which can suffers the gravity, the variable buoyancy and Froude-Krylov loads. Finally, the numerical modeling for the system of a spherical buoy moored by a cable is established, and a virtual simulation is proceeded with the X- and Y-directional linear waves and the X-directional current. The comparison with the commercial simulation code Proteus DS indicates that the system is accurately analyzed by the numerical modeling. The tensions within the cable, the motions of the system, and the relationship between the motions and waves are illustrated according to the defined sea state. The dynamics of the cables should be considered in analyzing the floating system of a spherical buoy moored by a cable.

关键词： numerical modeling dynamic simulation spherical buoy mooring cable dynamics of cable

Harnessing data using symbolic regression methods for discovering novel paradigms in physics

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 1-11页

作者： Jianyang Guo wan-Jian Yin College of Energy Soochow Institute for Energy and Materials Innovations(SIEMIS)Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy TechnologiesSoochow UniversitySuzhou 215006China Shanghai Qi Zhi Institute Shanghai 200232China Light Industry Institute of Electrochemical Power Sources Soochow UniversitySuzhou 215006China

In recent years,machine-learning methods have profoundly impacted research in the interdisciplinary fields of ***,most machine-learning models lack interpretability,and physicists doubt the credibility of their conclusions because they cannot be combined with prior physical ***,this review focuses on symbolic regression,which is an interpretable machine-learning ***,the relevant concepts of machine learning are introduced in conjunction with ***,we provide an overview of symbolic regression ***,the recent directions for the application of symbolic regression methods in different subfields of physics are outlined,and an overview of the ways in which the applications of symbolic regression have evolved in the realm of physics is *** major aim of this review is to introduce the basic principles of symbolic regression and explain its applications in the field of physics.

关键词： machine learning genetic programming symbolic regression

Preparation of Multifunctional β-hemihydrate Gypsum using Oyster Shell Powder as the Partial Replacement of Ag/TiO2 Particle

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Journal of Wuhan University of Technology(Materials Science) 2020年第6期35卷 1073-1080页

作者： wan Lu China Shanghai Architectural Design&Reserach Institute Co.Ltd. Shanghai 20062China

This work aimed to use oyster shell powder (OSP) as the partial replacement of Ag/TiO2 particle to obtain multifunctional β-hemihydrate ***,the β-hemihydrate gypsum was mixed with different contents of OSP and Ag/TiO2 *** and MB removal experiments were conducted to assess the antibacterial characteristic and photocatalytic activity of β-hemihydrate gypsum with Ag/TiO2 particle and ***,the formaldehyde degradation test was carried out to evaluate its formaldehyde removal ***,their setting times,compressive and flexural strengths at 1,3,and 28 days were comparatively *** experimental results prove that the composite use of OSP and Ag/TiO2 particle provide feasible multifunction for the β-hemihydrate *** can further improve the bactericidal rates and exhibit extra MB removal ratios compared with the gypsum plasters with single Ag/TiO2 ***,they can increase the formaldehyde degradation ratios,and this promotion is related to the introduction of Ag/TiO2 ***,OSP delays the initial setting time but promotes the final setting time of β-hemihydrate gypsum,and Ag/TiO2 particle hardly affects the setting ***,OSP reduces the strengths of plasters at 1,3,and 28 *** in general,the composite addition of OSP and Ag/TiO2 particle increase the compressive and flexural strengths of gypsum plasters at 1,3,and 28 *** results provide theoretical guidance for the recycling of OSP and the preparation of gypsum-based products with antibacterial and formaldehyde degradation capabilities.

关键词： oyster shell powder Ag/TiO2 particle β-hemihydrate gypsum bactericidal rate setting times

Numerical Modeling of a Spar Platform Tethered by a Mooring Cable

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 785-792页

作者： ZHU Xiangqian YOO wan-Suk Computer Aided Engineering Laboratory School of Mechanical Engineering Pusan National University

Virtual simulation is an economical and efficient method in mechanical system design. Numerical modeling of a spar platform, tethered by a mooring cable with a spherical joint is developed for the dynamic simulation of the floating structure in ocean. The geometry modeling of the spar is created using finite element methods. The submerged part of the spar bears the buoyancy, hydrodynamic drag force, and effect of the added mass and Froude-Krylov force. Strip theory is used to sum up the forces acting on the elements. The geometry modeling of the cable is established based on the lumped-mass-and-spring modeling through which the cable is divided into 10 elements. A new element-fixed local frame is used, which is created by the element orientation vector and relative velocity of the fluid, to express the loads acting on the cable. The bottom of the cable is fixed on the seabed by spring forces, while the top of the cable is connected to the bottom of the spar platform by a modified spherical joint. This system suffers the propagating wave and current in the X-direction and the linear wave theory is applied for setting of the propagating wave. Based on the numerical modeling, the displacement-load relationships are analyzed, and the simulation results of the numerical modeling are compared with those by the commercial simulation code, Proteus DS. The comparison indicates that the numerical modeling of the spar platform tethered by a mooring cable is well developed, which provides an instruction for the optimization of a floating structure tethered by a mooring cable system.

关键词： numerical modeling dynamic simulation spar platform mooring cable spherical joint

Improved EMD Based on Piecewise Cubic Hermite Interpolation and Mirror Extension

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Chinese Journal of Electronics 2020年第5期29卷 899-905页

作者： ZHANG Xuejun HUO Yan wan Dongsheng College of Electronic and Optical Engineering Nanjing University of Posts and Telecommunications Nation-Local Joint Project Engineering Laboratory of RF Integration and Micropackage

This paper proposes an improved Empirical mode decomposition(EMD) method piecewise cubic hermite interpolation and mirror extension. Firstly, mirror expansion method is used to expand preliminary signal endpoint; then the piecewise cubic Hermite interpolation algorithm is applied to obtain the envelopes. Finally Intrinsic mode functions(IMFs) are obtained through improved EMD(MPC-HEMD). Through the analysis on simulation signals and Electroencephalogram(EEG)signals, we found that the new method was better than the traditional method.

关键词： Common spatial pattern EEG signal Empirical mode decomposition Feature extraction Mirror expansion Piecewise cubic Hermite interpolation

MMOS+ Ordering Search Method for Bayesian Network Structure Learning and Its Application

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Chinese Journal of Electronics 2020年第1期29卷 147-153页

作者： HE Chuchao GAO Xiaoguang wan Kaifang School of Electronic Information Northwestern Polytechnic University

To address the problem of a reduced efficiency due to an increase of the search space, it has been proposed that priors could be added as constraints to the OS+ algorithm, which are Parent and children(PC) sets of each node obtained using the Max-min parent and children(MMPC) algorithm. Experimental results indicate that compared to other competitive methods, the proposed algorithm yields better solutions while maintaining high efficiency. Bayesian network(BN) sensitivity analysis is also proposed, which allows the network structure to be determined via a proposed ordering search method. We performed sensitivity analysis to determine the accuracy of the airborne avionics system, for which a simulation model is constructed to generate data samples, and the main effect of each error index is obtained using different sensitivity analysis methods. Experimental results indicate that the proposed BN method produces more accurate results when there is insufficient sample data, and this method can elucidate causal relationships that are present in the data.

关键词： Bayesian network Structure learning Ordering search Sensitivity analysis Airborne avionics system

Strategic Peer-to-peer Energy Trading Framework Considering Distribution Network Constraints

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 770-780页

作者： Yanbo Jia Can wan Biao Li College of Electrical Engineering Zhejiang UniversityHangzhou 310027China

With the development of smart home energy management technology,prosumers are endowed with increased initiative in peer-to-peer(P2P)transactions,bringing new potential for cost *** this study,a novel strategic P2P energy trading framework is proposed considering the impact of network constraints on personal transaction *** can estimate the allowed power injection before engaging in the P2P energy trading,which is solved in a distributed manner based on the sharing form alternating direction method of multipliers(ADMM)*** quantify the network usage cost for each prosumer and promote local transactions among prosumers at the same bus,a modified continuous double auction(CDA)matching algorithm is proposed including a transaction *** adaptive aggressiveness-based bidding strategy is generated considering the risk of uncertainty in real-time energy delivery amount under the limitations of the distribution *** proposed strategic P2P energy trading framework is tested with the IEEE 37-bus distribution network and it is effective in creating profits for prosumers and supporting distribution network operations.

关键词： Bidding strategy continuous double auction(CDA) distribution network distributed algorithm peer-topeer(P2P)transaction