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基于缺氧/厌氧/好氧/后缺氧工艺的活性污泥模型的校正及验证(英文)

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第9期15卷 743-752页

作者： Xiang HU Li XIE Chuang MI dian-hai yang State Key Laboratory of Pollution Control and Resources Reuse Tongji University

研究目的:以中试规模的缺氧/厌氧/好氧/后缺氧污水处理工艺为研究对象,利用BioWin软件平台及其内嵌的通用活性污泥数学模型,建立该工艺的模拟模型并进行校正及验证,为优化该工艺的设计及运行提供指导。创新要点:成功建立了缺氧/厌氧/好... 详细信息

研究目的:以中试规模的缺氧/厌氧/好氧/后缺氧污水处理工艺为研究对象,利用BioWin软件平台及其内嵌的通用活性污泥数学模型,建立该工艺的模拟模型并进行校正及验证,为优化该工艺的设计及运行提供指导。创新要点:成功建立了缺氧/厌氧/好氧/后缺氧工艺的活性污泥数学模型,甄别出对模型输出有显著影响的灵敏性参数。研究方法:通过呼吸试验获取进水水质特征,利用BioWinTM软件平台及其内嵌的通用活性污泥数学模型,建立该工艺的模拟模型,利用模型缺省值进行初步稳态模拟,借助灵敏度分析方法筛选出重要的化学计量学参数及动力学参数并进行模型校正,利用校正后的模型对该工艺进行了动态模拟。重要结论:灵敏度分析可优化模型的校正过程,该工艺出水水质对异养菌(OHOs)和氨氧化菌(AOB)(YH、μmaxH、Ks、bH、μmaxA、KNH4A和baeroa,A)的灵敏度较高。校正后的模型稳态模拟出水水质(pH、COD、TN、NH4+-N、NO2--N、NO3--N和TP)控制在与实测出水相应的95%置信区间内(图5),表明稳态模型建模成功,在此基础上运行的动态模拟准确地反映了工艺实际运行中的浓度变化趋势(图6),具有良好的模拟效果。

关键词：活性污泥模型模拟校正验证灵敏度分析

Effect of order–disorder transition on thermodynamic and electronic properties of σ and χ phases in W–Re alloy: the first-principles calculation

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Tungsten 2025年第1期 195-213页

作者： Zhi-Peng Zhu dian Jia William Yi Wang Jun-Lei Yin Xing-Yu Gao Shu-Feng yang hai-Feng Song Jin-Shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The Tungsten-Rhenium(W-Re) alloys,celebrated for their high melting point,strength at elevated temperatures,electrical resistivity,and radiation resistance,have been widely utilized in high-temperature components,aerospace,electronics,and nuclear *** constituents of the topologically close-packed(TCP) phases,the sigma phase(σ) and chi phase(χ) formed within W-Re alloys wield considerable influence on the mechanical properties and the stability of the *** calculations were utilized in the present work to explore the structural,thermodynamic,and electronic properties of both ordered and disordered configurations within the σ and χ phases,culminating in a systematic elucidation of the higher phase stability exhibited by the ordered *** is found that the bulk modulus of these two phases is directly proportional to the concentration of Re in the alloy,while the equilibrium volume is inversely *** thermodynamic parameters of the σ and χ phases are calculated via the mean-field potential *** similar trends observed in the isobaric heat capacity,enthalpy increment,and entropy change curves for these two phases suggest they possess comparable thermodynamic *** is noteworthy that the contribution of ionic vibrations predominantly affects the isobaric heat capacity,while the contribution of thermal electronic excitations increases linearly with *** the structure and thermodynamic properties of TCP phases in W-Re alloys at low temperatures has profound significance for optimizing material performance,microstructures features,establishing theoretical foundations,and predicting material behavior.

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B_(111),B_(112),_(B113),and B_(114):The most stable core-shell borospherenes with an icosahedral B_(12) core at the center exhibiting superatomic behaviors

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Nano Research 2021年第12期14卷 4719-4724页

作者： Min Zhang hai-Gang Lu Si-dian Li Institute of Molecular Science Shanxi UniversityTaiyuan030006China

Boron allotropes are known to be predominately constructed by icosahedral B_(12) cages,while icosahedral-B_(12) stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size range between B_(98)–B_(102).However,the thermodynamically most stable core-shell borospherenes with a B_(12) icosahedron at the center still remains *** on the structural motif of D5h C_(70) and extensive first-principles theory calculations,we predict herein the high-symmetry C5v B111+(3)which satisfies the Wade’s n+1 and n+2 skeletal electron counting rules exactly and the approximately electron sufficient Cs B_(111)(4),Cs B_(112)(5),Cs B_(113)(6),and Cs B_(114)(7)which are the most stable neutral core-shell borospherenes with a B_(12) icosahedron at the center reported to date in the size range between B_(68)–B_(130),with Cs B112(5)being the thermodynamically most favorite species in the *** orbital and bonding analyses indicate that these spherically aromatic species all contain a negatively charged icosahedral B_(122)−core at the center which exhibits typical superatomic behaviors in the electronic configuration of 1S21P61D101F8,with its dangling valences saturated by twelve radial B-B 2c-2eσbonds between the B_(12) inner core and the B_(70) outer *** infrared(IR)and Raman spectra of the concerned species are computationally simulated to facilitate their future characterizations.

关键词： first-principles theory borospherenes structures bonding superatomic behaviors spherical aromaticity

Microstructure and Mechanical Properties of Semi-continuous Equal-channel Angular Extruded Interstitial-free Steel

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Journal of Iron and Steel Research International 2016年第2期23卷 160-165页

作者： Bo YAN Si-hai JIAO dian-hua ZHANG State Key Laboratory of Rolling and Automation Northeastern University Research and Development Center Baoshan Iron and Steel Co.Ltd.

An innovative method called semi-continuous equal channel angular extrusion （SC-ECAE） has been devel- oped to produce ullrafine grained steel by inducing severe plastic deformation. In contrast to the external forces that are exerted on specimens in traditional ECAE, the driving forces are applied on the dies in the novel SC EACE process. Commercial interslitial-free steel sheets with width of 160 mm and tbickness of 2 mm were processed re peatedly to various passes at room temperature using this method. The microstructural evolution was characterized using high-resolution electron backscatter diffraction （EBSD）, and the mechanical properties were investigated by tensile testing. The EBSD images indicated that the fraction of high angle boundaries （HABs） began to increase gradually after four passes; after six passes, elongated HAB structures with nearly submicron-scale average spacings were formed. The tensile testing results showed that strengthening was accompanied by a decrease in tensile ductili- ly, but no significant anisotropy was observed. After 10 passes, a final HAB fraction of about 90% and an overall grain size of 0.55 μm, yield strength of 638.7 MPa, an ultimate tensile strength （UTS） of 710.3 MPa, and a totfd elongation of 12.0 % were obtained.

关键词： severe plastic deformation semi-continuous equal channel angular extrusion IF steel ultrafine grainedstructure EBSD

Sensitivity of the Impact Toughness and Microstructure of 15CrNi3MoV Steel Under Different Quenching Rates

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Acta Metallurgica Sinica(English Letters) 2023年第10期36卷 1735-1748页

作者： Bing Wang Hong-Lin Zhang Bin Xu hai-yang Jiang Ming-Yue Sun dian-Zhong Li Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The sensitivities of the mechanical properties and microstructure of 15CrNi3MoV alloy steel under different quenching rates were investigated in the present *** subjection to quenching with four different cooling rates(water cooling,forced air cooling,static air cooling and furnace cooling)followed by tempering,the microstructure was characterized by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),and transmission electron microscopy(TEM);and the low-temperature(−20°C)impact toughness was *** results showed that the tempered microstructure and mechanical properties had high sensitivity to the quenching *** a decrease in the quenching rate,the low-temperature impact energy of tempered specimens decreased with increasing ***,the fracture morphology changed from completely ductile to *** addition,as the quenching cooling rate decreased,the as-quenched matrix changed from a lathy to a polygonal structure with the presence of carbides and martensite-austenite(M-A)constituents,and the effective grain size *** martensite with dispersed fine carbides was found in the tempered water cooling specimen,and tempered bainite with a polygonal structure containing large carbides and rare incomplete undecomposed M-A constituents was found in the tempered forced air cooling,static air cooling and furnace cooling *** small effective grain size and fine carbides contributed to the good temperature impact toughness of the tempered water cooling specimens.

关键词： Alloy steel Quenching cooling rate Impact toughness Martensite-austenite(M-A)constituents Carbides

Hydrothermal Synthesis and Structure Characterization of Open-framework Cobalt-tungsten Phosphate [H_3NCH_2CH_2NH_3]_3[Co_3W_4P_4O_(28)]

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Chemical Research in Chinese Universities 2010年第6期26卷 862-865页

作者： ZHANG Yan-lin YU hai-hui ZHOU yang HOU dian-hui KONG Li College of Chemical Engineering Northeast Dianli University Jilin 132012 P. R. China College of Chemical and Materials Engineering Jilin Institute of Chemical Technology Jilin 132012 P. R. China

A new three-dimensional open-framework cobalt（Ⅱ）-tungsten（Ⅵ） phosphate,[H3NCH2CH2NH3]3·[Co3W4P4O28]（1） has been synthesized from the reaction of CoCl2·6H2O,WO3,H3PO4,ethylenediamine and *** title compound was fully characterized by infrared spectroscopy,elemental analysis,magnetic properties,thermogravimetric analysis,XPS and single-crystal X-ray *** compound crystallized in a tetragonal space group I4（1）/a with a=1.7118（4） nm,c=1.0773（2） nm,V =3.1568（11） nm3,Z =4.

关键词： Hydrothermal synthesis Crystal structure Polyoxometalate

Hydrogen storage thermodynamics and dynamics of La-Mg-Ni-based LaMg12-type alloys synthesized by mechanical milling

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Rare Metals 2019年第12期38卷 1144-1152页

作者： yang-Huan Zhang Peng-Fei Gong Long-Wen Li Hao Sun dian-Chen Feng Shi-hai Guo Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010China Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China

Nanocrystalline/amorphous LaMg(12)-type alloyNi composites with a nominal composition of LaMg(11)Ni+x wt% Ni(x=100,200) were synthesized by mechanical *** of Ni content and milling time on the gaseous hydrogen storage thermodynamics and dynamics of alloys were systematically *** hydrogen desorption properties were studied by Sievert apparatus and a differential scanning calorimeter(DSC).Thermodynamic parameters(△H and ΔS) for the hydrogen absorption and desorption of alloys were calculated by Van't Hoff *** desorption activation energy of alloy hydride was estimated by Arrhenius and Kissinger *** increase in Ni content has a slight effect on the thermodynamic properties of alloys,but it significantly enhances the hydrogen absorption and desorption kinetics performance of ***,variation of milling time clearly affects the hydrogen storage properties of *** absorption capacity(C(100)~a) and hydrogen absorption saturation ratio(R(10)~a)(a ratio of the hydrogen absorption capacity at 10 min to the saturated hydrogen absorption capacity) have maximum values with milling time *** hydrogen desorption ratio(R(20)~d)(a ratio of the hydrogen desorption capacity at 20 min to the saturated hydrogen absorption capacity) always increases with milling time ***,prolonging milling time from 5 to 60 h makes R(20)~d increase from 10.89% to 16.36% for the x=100 alloy and from 13.93% to 21.68% for the x=200 alloy,respectively.

关键词： LaMg(12)alloy Mechanical milling Thermodynamics and dynamics Activation energy Hydrogen storage

Short-term traffic safety forecasting using Gaussian mixture model and Kalman filter

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第4期14卷 231-243页

作者： Sheng JIN dian-hai WANG Cheng XU Dong-fang MA College of Civil Engineering and Architecture Zhejiang University Zhejiang Police College

In this paper,a prediction model is developed that combines a Gaussian mixture model(GMM) and a Kalman filter for online forecasting of traffic safety on *** time-to-collision(TTC) samples are divided into two categories:those representing vehicles in risky situations and those in safe ***,the GMM is used to model the bimodal distribution of the TTC samples,and the maximum likelihood(ML) estimation parameters of the TTC distribution are obtained using the expectation-maximization(EM) *** propose a new traffic safety indicator,named the proportion of exposure to traffic conflicts(PETTC),for assessing the risk and predicting the safety of expressway traffic.A Kalman filter is applied to forecast the short-term safety indicator,PETTC,and solves the online safety prediction problem.A dataset collected from four different expressway locations is used for performance *** test results demonstrate the precision and robustness of the prediction model under different traffic conditions and using different *** results could help decision-makers to improve their online traffic safety forecasting and enable the optimal operation of expressway traffic management systems.

关键词： Forecasting Traffic safety Gaussian mixture model Kalman filter

Car-following theory of steady-state traffic flow using time-to-collision

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第8期12卷 645-654页

作者： Sheng JIN Zhi-yi HUANG Peng-fei TAO dian-hai WANG College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China College of Traffic and Transportation Jilin University Changchun 130022 China

The conventional car-following theory is based on the assumption that vehicles will travel along the center line of lanes. However, according to the field survey data, in complex traffic conditions, a lateral separation between the leader and the follower frequently occurs. Accordingly, by taking lateral separation into account, we redefined the equation of time-to-collision (TTC) using visual angle information. Based on the stimulus-response framework, TTC was introduced into the basic General Motors (GM) model as a stimulus, and a non-lane-based car-following model of steady-state traffic flow was developed. The property of flow-density relationship was further investigated after integrating the proposed car-following model with different parameters. The results imply that the property of steady-state traffic flow and the capacity of each lane are highly relevant to the microscopic staggered car-following behavior, and the proposed model significantly enhances the practicality of the human driving behavior model.

关键词： Non-lane-based Visual angle Time-to-collision(TTC) Flow-density curve