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Two new C-glycosylflavones from Mimosa pudica

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Chinese Chemical Letters 2007年第10期18卷 1231-1234页

作者： Ke Yuan Jie Li Lu An Jia jian xin zhu College of Food and Pharmacy Zhejiang Forestry University Linan 311300 China College of Pharmacy Henan University of Traditional Chinese Medicine Zhengzhou 450008 China

Two new C-glycosylflavones were isolated from the whole plant of Mimosa pudica, and their structures were determined as 6,7,3＇,4＇-tetrahydroxyl-8-C-[α-L-rhamnopyranosyl-（1 → 2）]-β-D-glucopyranosyl flavone （1）, 5,7,3＇,4＇-tetrahydroxy-8-C[β-D- apiose-（1 → 4）]-β-D-glycopyranosyl flavone （2）. Their structures elucidated by chemical and spectroscopic analysis including IR, MS, 1D and 2D NMR spectra.

关键词： Mimosa pudica C-glycosylflavones

Location of Caspase 3-like Protease in the Development of Sieve Element and Tracheary Element of Stem in Cucurbita moschata

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Journal of Integrative Plant Biology 2008年第12期50卷 1499-1507页

作者： Xia Hao Jie Qian Shan Xu xin Song jian zhu School of Life Science and Technology Tongji University Shanghai 200092 China

The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color （under light microscopy） and gold particles （under transmission electron microscopy） for detecting caspase 3-like protease was mainly displayed in inner phloem, external phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.

关键词： caspase 3-like protease Cucurbita moschata immunoelectron microscopy P-protein bodies programmed cell death.

Robust design and optimization for autonomous PV-wind hybrid power systems

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 401-409页

作者： Jun-hai SHI Zhi-dan ZHONG xin-jian zhu Guang-yi CAO Institute of Fuel Cells Shanghai Jiao Tong University Shanghai 200240 China

This study presents a robust design method for autonomous photovoltaic (PV)-wind hybrid power systems to obtain an optimum system configuration insensitive to design variable variations. This issue has been formulated as a constraint multi-objective optimization problem, which is solved by a multi-objective genetic algorithm, NSGA-II. Monte Carlo Simulation (MCS) method, combined with Latin Hypercube Sampling (LHS), is applied to evaluate the stochastic system performance. The potential of the proposed method has been demonstrated by a conceptual system design. A comparative study between the proposed robust method and the deterministic method presented in literature has been conducted. The results indicate that the proposed method can find a large mount of Pareto optimal system configurations with better compromising performance than the deterministic method. The trade-off information may be derived by a systematical comparison of these configurations. The proposed robust design method should be useful for hybrid power systems that require both optimality and robustness.

关键词： PV-wind power system Robust design Constraint multi-objective optimizations Multi-objective genetic algorithms Monte Carlo Simulation (MCS) Latin Hypercube Sampling (LHS)

SOFC temperature evaluation based on an adaptive fuzzy controller

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 688-694页

作者： Xiao-juan WU xin-jian zhu Guang-yi CAO Heng-yong TU Institute of Fuel Cell Department of Automation Shanghai Jiao Tong University Shanghai 200030 China

The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.

关键词： Solid oxide fuel cell (SOFC) Temperature control Adaptive fuzzy controller Affine temperature model

Numerical simulation of a direct internal reforming solid oxide fuel cell using computational fluid dynamics method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第7期9卷 961-969页

作者： Jun LI Ying-wei KANG Guang-yi CAO xin-jian zhu Heng-yong TU jian LI Institute of Fuel Cell Department of Automalion Shanghai Jiao Tong University Shanghai 200240 China College of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

A detailed mathematical model of a direct internal reforming solid oxide fuel cell(DIR-SOFC) incorporating with simulation of chemical and physical processes in the fuel cell is presented. The model is developed based on the reforming and electrochemical reaction mechanisms,mass and energy conservation,and heat transfer. A computational fluid dynamics(CFD) method is used for solving the complicated multiple partial differential equations(PDEs) to obtain the numerical approximations. The resulting distributions of chemical species concentrations,temperature and current density in a cross-flow DIR-SOFC are given and analyzed in detail. Further,the influence between distributions of chemical species concentrations,temperature and current density during the simulation is illustrated and discussed. The heat and mass transfer,and the kinetics of reforming and electrochemical reactions have significant effects on the parameter distributions within the cell. The results show the particular characteristics of the DIR-SOFC among fuel cells,and can aid in stack design and control.

关键词： Direct internal reforming (DIR) Solid oxide fuel cell (SOFC) Computational fluid dynamics (CFD) Numerical simulation

Predictive control of a direct internal reforming SOFC using a self recurrent wavelet network model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第1期11卷 61-70页

作者： Jun LI Nan GAO Guang-yi CAO Heng-yong TU Ming-ruo HU xin-jian zhu jian LI Institute of Fuel Cell Department of Automation Shanghai Jiao Tong University Shanghai 200240 China Department of Mathematics Shanghai University Shanghai 200444 China College of Materials Science and Engineering Huazhong University of Seience and Technology Wuhan 430074 China

In this paper,an application of a nonlinear predictive controller based on a self recurrent wavelet network (SRWN) model for a direct internal reforming solid oxide fuel cell (DIR-SOFC) is presented. As operating temperature and fuel utilization are two important parameters,the SOFC is identified using an SRWN with inlet fuel flow rate,inlet air flow rate and current as inputs,and temperature and fuel utilization as outputs. To improve the operating performance of the DIR-SOFC and guarantee proper operating conditions,the nonlinear predictive control is implemented using the off-line trained and on-line modified SRWN model,to manipulate the inlet flow rates to keep the temperature and the fuel utilization at desired levels. Simulation results show satisfactory predictive accuracy of the SRWN model,and demonstrate the excellence of the SRWN-based predictive controller for the DIR-SOFC.

关键词： Direct internal reforming (DIR) Solid oxide fuel cell (SOFC) Predictive control Self recurrent wavelet network (SRWN)

Recent developments in activities, utilization and sources of cellulase

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Forestry Studies in China 2009年第3期11卷 202-207页

作者： FENG Yue jianG jian-xin zhu Li-wei College of Materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

One of the latest sources of alternative energy, bioethanol, has been the focus of modem research, The production of bioethanol is commonly restricted by the activity of cellulase. Therefore, cellulase has become one of the critical issues in the conversion of lignocelluloses to bioethanol. This article is an overview of the sources and factors affecting enzyme activity, as well as methods of evaluation and utilizations of cellulase. We conclude that a combination of cellulases from various strains can enhance hydrolysis of substrates. Large enough amounts of cellobiase or sufficient cellobiase activity can reduce the inhibition to exoglucanase activity of cellobiose. Characterization and exploitation of cellulase should focus on a definite substrate. Promotion and mixed incubation of strains can reduce the cost of industrial utilization of cellulase.

关键词： cellulase strains inhibitor activity evaluation cellulase utilization

A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 263-270页

作者： Chun-hua LI xin-jian zhu Guang-yi CAO Wan-qi HU Sheng SUI Ming-ruo HU Fuel Cell Research Institute Shanghai Jiao Tong University Shanghai 200240. China Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

To extract the maximum power from a photovoltaic （PV） energy system, the real-time maximum power point （MPP） of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller （FNNC）, which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the filzzy logic control algorithm.

关键词： Photovoltaic array Maximum power point tracking (MPPT) Fuzzy neural network controller (FNNC) Radial basis function neural network (RBFNN)

New computational treatment of optical wave propagation in lossy waveguides

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Frontiers of Information Technology & Electronic Engineering 2015年第8期16卷 646-653页

作者： jian-xin zhu Guan-jie WANG Department of Mathematics Zhejiang University

In this paper, the optical wave propagation in lossy waveguides is described by the Helmholtz equation with the complex refractive-index, and the Chebyshev pseudospectral method is used to discretize the transverse operator of the equation. Meanwhile, an operator marching method, a one-way re-formulation based on the Dirichlet- to-Neumann （DtN） map, is improved to solve the equation. NumericM examples show that our treatment is more efficient.

关键词： Adjoint operator Orthogonal Chebyshev Pseudospectral method Dirichlet-to-Neumann map