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New loop pairing criterion based on interaction and integrity considerations

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第5期11卷 381-393页

作者： Ling-jian YE Zhi-huan song Institute of Industrial Process Control Zhejiang University Hangzhou 31002 7 China

Loop pairing is one of the major concerns when designing decentralized control systems for multivariable *** existing pairing tools,such as the relative gain array(RGA) method,have shortcomings both in measuring interaction and in integrity *** evaluate the overall interaction among loops,we propose a statistics-based criterion via enumerating all possible combinations of loop ***,we quantify the traditional concept of integrity to represent the extent of integrity of a decentralized control ***,we propose that a pairing decision should be made by taking both factors into *** examples are provided to illustrate the effectiveness of the proposed criterion.

关键词： Control structure design Decentralized control Interaction analysis Variable pairing Relative gain array

Uniqueness and Radial Symmetry of Least Energy Solution for a Semilinear Neumann Problem

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 473-482页

作者： Zheng-ping Wang huan-song Zhou Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences P.O.Box 71010 Wuhan 430071 China

Consider the following Neumann problem d△u- u ＋ k（x）u^p = 0 and u 〉 0 in B1, δu/δv =0 on OB1,where d 〉 0, B1 is the unit ball in R^N, k（x） = k（｜x｜） ≠ 0 is nonnegative and in C（-↑B1）, 1 〈 p 〈 N＋2/N-2 with N≥ 3. It was shown in [2] that, for any d 〉 0, problem （＊） has no nonconstant radially symmetric least energy solution if k（x） ≡ 1. By an implicit function theorem we prove that there is d0 〉 0 such that （＊） has a unique radially symmetric least energy solution if d 〉 d0, this solution is constant if k（x） ≡ 1 and nonconstant if k（x） ≠ 1. In particular, for k（x） ≡ 1, do can be expressed explicitly.

关键词： Implicit function theorem least energy solution radial symmetry Neumann problem elliptic

A Variational ODE and its Application to an Elliptic Problem

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Acta Mathematicae Applicatae Sinica 2007年第4期23卷 685-696页

作者： huan-song Zhou Hong-bo Zhu Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences P.O. Box 71010 Wuhan 430071 China

In this paper, we consider the following ODE problem { （-u＂（τ）＋（N-1）（N-3）/4τ^2 ）u（τ）＋λu（τ）=f（τ,τ（1-N）/2 u）u（τ）,τ〉0, u∈H, N≥3. （P）,where f ∈ C（（0,＋∞） ×R,R）, f（τ,s） goes t... 详细信息

In this paper, we consider the following ODE problem { （-u＂（τ）＋（N-1）（N-3）/4τ^2 ）u（τ）＋λu（τ）=f（τ,τ（1-N）/2 u）u（τ）,τ〉0, u∈H, N≥3. （P）,where f ∈ C（（0,＋∞） ×R,R）, f（τ,s） goes to p（τ） and q（τ） uniformly in τ 〉 0 as s→ 0 and s→＋∞ respectively, 0≤ p（τ） ≤ q（τ） ∈L^∞（0,∞）. Moreover, for τ 〉 0, f（τ, s） is nondecreasing in s≥ 0. Some existence and non-existence of positive solutions to problem （P） are proved without assuming that p（τ） = 0 and q（τ） has a limit at infinity. Based on these results, we get the existence of positive solutions for an elliptic problem.

关键词： Elliptic equation asymptotically linear mountain pass theorem

Subspace identification for continuous-time errors-in-variables model from sampled data

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第8期10卷 1177-1186页

作者： Ping WU Chun-jie YANG Zhi-huan song State Key Lab of Industrial Control Technology Zhejiang University Hangzhou 310027 China

We study the subspace identification for the continuous-time errors-in-variables model from sampled ***,the filtering approach is applied to handle the time-derivative problem inherent in continuous-time *** generalized Poisson moment functional is focused.A total least squares equation based on this filtering approach is *** by the idea of discrete-time subspace identification based on principal component analysis,we develop two algorithms to deliver consistent estimates for the continuous-time errors-in-variables model by introducing two different instrumental *** determination and other instrumental variables are *** usefulness of the proposed algorithms is illustrated through numerical simulation.

关键词： System identification Errors-in-variables Continuous-time system Subspace method

Establishment of mixed plantations of Pinus sylvestris *** and Populus×xiaozhuanica may not be appropriate:evidence from litter decomposition

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Journal of Plant Ecology 2019年第5期12卷 857-870页

作者： huan-huan song Tao Yan De-Hui Zeng CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Daqinggou Ecological Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China

Aims Mongolian pine(Pinus sylvestris ***)and Xiaozhuan poplar(Populus×xiaozhuanica)are two predominant afforestation tree species in the semi-arid sandy lands of northeast china,which are characterized by poor soil *** litter decomposition plays a critical role in regulating nutrient cycling in terrestrial *** of broadleaf litter to conifer litter is expected to improve litter decomposition and soil fertility,and thus ***,the effects on the decomposition of litter mixture of the above two tree species are not well ***,it is essential to assess the decomposition performance of litter mixture with the aim of improving forest nutrient management and the establishment of mixed *** forest manage-ment practice is critical for the sustainability of site productivity in plantation *** We conducted a field litterbag decomposition transplant experi-ment for single pine litter,single poplar litter and their mixture in a pine stand,a poplar stand and an adjacent grassland for 16 months in the Keerqin Sandy Lands,northeast *** Findings After 16 months of incubation,there remained significantly more litter mass of pine(73.8%)than of poplar(67.2%).the mass remaining was positively correlated with litter carbon(c):nitrogen(N),c:phosphorus(P)and lignin:N ratios,and negatively with litter N and P concentrations,which suggests that initial litter chemical properties were an important factor affecting litter ***,net N and P immobilizations were observed during *** indicates that litter decomposition in this area was N-limited as N was progressively immobilized,and then tended to induce P ***,we strongly recommend prohibiting litter harvesting by local residents to maintain soil fertility in this nutrient-poor *** results do not support the home-field advantage hypothesis,as illustrated by the fact that,in most cases,mass loss of

关键词： litter mass remaining nutrient immobilization litter mixture additive effect home-field advantage nutrient-poor area

Estimation of Sediment Incipient Velocity Using B-Mode Ultrasound Imaging Technique

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Wuhan University Journal of Natural Sciences 2015年第2期20卷 180-184页

作者： song huan ZOU Xianjian Electronic Information School Wuhan University

Sediment incipient velocity （SIV） is a vital parameter for sediment research and river dynamics. This paper describes a novel method of estimating SIV based on the known flow velocity in the movable-bed model experiment. In this method, we use B-mode ultrasound imaging technique to get video images of moving particles and topography under water. By statistical analysis of video images, the relationship between the average number of imaging particles and flow velocity is obtained. The relationship between the change rate of average number and flow velocity is analyzed in sediment incipient process. These relationships are used to estimate the SIV. Lastly, the changed topography verifies the estimated velocity. The results show there is a sudden change in these relationships which can be used to estimate the SIV with high resolution by using a B-mode ultrasound device. The estimated SIV of plastic sands （particle size is about 0.25 mm） is 3.64 cm · s^-1 and the estimated SIV of natural sands （particle size is about 0.25 mm） is 5.47 cm · s^-1in the same condition.

关键词： sediment movement incipient velocity B-mode ultrasound imaging technique particle size

Asymptotic Behavior of Least Energy Solutions for a Fractional Laplacian Eigenvalue Problem on R^(N)

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Acta Mathematica Sinica,English Series 2023年第4期39卷 707-727页

作者： Yun Bo WANG Xiao Yu ZENG huan song ZHOU School of Mathematics and Center for Nonlinear Studies Northwest UniversityXi'an 710127P.R.China Center for Mathematical Sciences Wuhan University of TechnologyWuhan 430070P.R.China

We are interested in the existence and asymptotic behavior for the least energy solutions of the following fractional eigenvalue problem (P)(-△)^(s)u+V(x)u=μu+am(x)|u|^(4s/N)u,∫_(R^(N))|u|^(2)dx=1,u∈H^(s)(R^(N)),where s∈(0,1),μ∈R,a>0,V(x)and m(x)are L^(∞)(R^(N))functions with N≥*** prove that there is a threshold a^(*)_(s)>0 such that problem(P)has a least energy solution u_(a)(x)for each a∈(0,a^(*)_(s))and u_(a)blows up,as a↗a^(*)_(s),at some point x_(0)∈R^(N),which makes V(x_(0))be the minimum and m(x_(0))be the ***,the precise blowup rates for u_(a)are obtained under suitable conditions on V(x)and m(x).

关键词： Laplacian eigenvalue problem constrained variational problem energ mates

Measurements of HO2 uptake coefficient on aqueous（NH4）2SO4 aerosol using aerosol flow tube with LIF system

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Chinese Chemical Letters 2019年第12期30卷 2236-2240页

作者： Qi Zou huan song Mingjin Tang Keding Lu College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China State Key Laboratory of Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

Laboratory studies of HO2 uptake coefficients,γ(HO2),were conducted at room temperature using an aerosol flow tube coupled with a laser induced fluorescence(LIF) *** measurement was conducted with atmospherically relevant HO2 concentrations(~1×10^9 molecule/cm^3) at 51% *** measured γ(HO2) onto aqueous(NH4)2 SO4 aerosol was 0.001±0.0007,which was consistent with the relatively low first-order loss rate of HO2 onto aqueous(NH4)2 SO4 ***γ(HO2) was elevated with increase of Cu(Ⅱ) concentrations in aqueous(NH4)2 SO4 *** threshold of Cu(Ⅱ) concentration was10^-3 mol/L for the dramatic increase of γ(HO2).It was found that γ(HO2) reached 0.1 when Cu(Ⅱ)concentration in aerosol was larger than 10^-3 mol/L,suggesting that γ(HO2) is very sensitive to concentration of transition metal ions in aerosol.

关键词： Heterogeneous reaction HO2 uptake coefficient Aerosol flow tube Laser induced fluorescence Transition metal ion

From External Accountability to Potential-Oriented Development:Quality Assurance System Building for Teacher Preparation in China

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ECNU Review of Education 2019年第2期2卷 137-165页

作者： huan song Miao Xu Center for Teacher Education Research Beijing Normal University Chinese Education and Social Development Research Institute of Beijing Normal University Education Center for Postgraduate of Education Degree Beijing Normal University

Purpose:From the perspective of performance standards-based teacher education,this article aimed to address progress and challenges of China’s teacher preparation quality assurance ***/Approach/Methods:This review is based on policy review and case *** to the existing research literature,this research sorted out the policies related to the quality assurance system for university-based teacher preparation in ***,this research selected teacher preparation programs from five cases of teacher education colleges of varied levels and used interviews to analyze their attitudes and ***:The analysis reveals that the quality system for university-based teacher preparation in China’s educational institutions has gone through two main stages:the building stage and the improvement *** internal policy tension in China’s teacher preparation quality assurance system is primarily centralized in the dissociation among and segmentation between the relevant standards for teacher *** is a distinction between“soft”and“hard”policy standards,and reforming the teacher certification testing system also brings a test-oriented bias and a separation of evaluation from *** of higher education are expected to follow the path of potential-oriented development and concentrate on cooperative partnerships between local communities and schools so as to nurture innovative,professional future educators with high ***/Value:This article provides a comprehensive and detailed policy analysis as well as empirical evidence for the quality assurance systemfor university-based teacher preparation in China.

关键词： Diversified accountability policy community potential-oriented development standardized teacher education teacher professionalization