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Modeling and experiments of chewing mechanical properties of pellet feed using discrete element method

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International Journal of Agricultural and Biological Engineering 2020年第4期13卷 37-44页

作者： Fei Peng Zhigang huang fang fang School of Artificial Intelligence Beijing Technology and Business UniversityBeijing 100048China Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics Beijing Technology andBusiness UniversityBeijing 100048China College of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

In order to explore the mechanical properties and breaking behavior of pellet feed during chewing,the experiments of texture mechanics,followed by the modeling and simulation of pellet feed based on the discrete element method were carried out in this *** wet basis moisture contents(8%,10%,12%,14%and 16%,respectively),two kinds of loading directions(L and D direction,respectively)of pig pellet feed were selected as ***,mechanical parameters including hardness,elasticity,tackiness and chewiness were measured by a texture *** results of compression tests showed that the hardness of pig pellet feed was 5.44-32.43 N,the elastic index was 0.04-0.94 mm,the tackiness was 0.07-6.63 N,the chewiness was 5.52-27.39 ***,the hardness,tackiness and chewiness of pig pellet feed decreased significantly with the increase of moisture content but the elasticity showed an adverse varying *** hardness,elasticity,tackiness and chewiness along D direction outweighed that of L direction in numerical data at the same moisture ***,the chewing and breaking processes of pellet feed were simulated based on the discrete element method(DEM)combined with bonding particle model,in which the whole pellet feed were considered as agglomerations of micro-particles and broke when the stress between micro-particles had exceeded the maximum ***-parameter optimization experiments were carried out using quadratic orthogonal rotation design,in which stiffness coefficient(X_(1)),critical stress(X2)and bonding radius(X_(3))were the influencing factors,hardness(Y_(1)),elasticity(Y_(2)),tackiness(Y_(3))and chewiness(Y_(4))were evaluating *** on the regression analysis of the Design-Expert 8.0.6 software and response surface analysis method,the relationship between the three influencing factors and evaluating indicators was *** similarity between experimental and simulated results in feed morphology and mechanical index proved

关键词： discrete element method pellet feed texture mechanics mechanical parameters palatability

Estimation method for parameters of overlapping nuclear pulse signal

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Nuclear Science and Techniques 2017年第1期28卷 80-87页

作者： Hong-Quan huang Xiao-Feng Yang Wei-Cheng Ding fang fang College of Nuclear Technology and Automation Engineering Chengdu University of Technology Fundamental Science on Radioactive Geology and Exploration Technology Laboratory East China Institute of Technology

Identification of nuclear pulse signal is of importance in radioactive measurements,especially in recognizing adjacent overlapping nuclear *** this article,we propose an estimation method for parameters of typical overlapping nuclear pulse ***,the nuclear pulses are regarded as individual genes and the norm is set as the fitness ***,the global optimal solution is found by searching the population of genetic algorithm,so as to estimate the parameters of nuclear *** high precision,this method can identify parameters of overlapping nuclear pulses in the Sallen-Key Gaussian signal decomposition *** pulse recognition method is of great significance to improve the precision of radioactive measurement and is suitable for serious overlap of nuclear pluses.

关键词： Nuclear pulse Overlapping Parameter identification

Premature thermal decomposition behavior of 3,4-dinitrofurazanfuroxan with certain types of nitrogen-rich compounds

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Defence Technology（防务技术） 2023年第8期26卷 102-110页

作者： Jiao huang Ru-fang Peng Bo Jin State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang621010SichuanPR China

3,4-Dinitrofurazanfuroxan(DNTF),as a high-energy-density material,features good thermal stability and wide *** study aimed to elucidate the thermal decomposition mechanism of DNTF combined with nitrogen-rich compounds containing *** thermal stabilities of DNTF and its hybrid systems were investigated using differential thermal analysis/thermogravimetry(TG),vacuum stability test,and accelerating rate calorimetry under isothermal,non-isothermal,and adiabatic conditions,*** showed that the thermal stability and thermal safety of DNTF significantly decreased after combining with nitrogen-rich compounds containing *** results showed that the activation energy of the DNTF hybrid systems was significantly lower than that of *** TGIR was used to monitor the generation of fugitive gases during the thermal decomposition of the DNTF/5-aminotetrazole(5-ATZ)***,the nitrogen-rich molecules containing N-H interacted extensively with DNTF,and this interaction accelerated the thermal degradation of DNTF.

关键词： DNTF NeH rich Nitrogen compounds Advanced thermal decomposition peak

Reconstructing Local Volatility Using Total Variation

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Acta Mathematica Sinica,English Series 2017年第2期33卷 263-277页

作者： Rui Yan ZHANG fang fang XU Jian Chao huang School of Mathematical Sciences University of the Chinese Academy of Sciences College of Mathematics and Systems Science Shandong University of Science and Technology Department of Mathematics Shanghai Jiao Tong University

The aim of this paper is to identify the volatility function in Dupire＇s equation from given option prices. This inverse problem is formulated as an infinite-dimensional minimization problem with PDE constraints. The computational cost of solving the discretized problem on a fine discretization level is expensive. A multi-grid method is proposed to explore the hierarchical structures of discretized problems on different levels. Computational examples are presented to demonstrate the efficiency of our method.

关键词： Volatility smile Dupire's equation finite difference optimization multigrid method

Amorpha-4,11-diene synthase: a key enzyme in artemisinin biosynthesis and engineering

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aBIOTECH 2021年第3期2卷 276-288页

作者： Jin Quan huang Xin fang National Key Laboratory of Plant Molecular Genetics Institute of Plant Physiology and Ecology/CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032People's Republic of China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650204YunnanPeople's Republic of China

Amorpha-4,11-diene synthase(ADS)catalyzes the first committed step in the artemisinin biosynthetic pathway,which is the first catalytic reaction enzymatically and genetically characterized in artemisinin *** advent of ADS in Artemisia annua is considered crucial for the emergence of the specialized artemisinin biosynthetic pathway in the *** production of amorpha-4,11-diene is a breakthrough in metabolic engineering and synthetic ***,numerous new techniques have been used in ADS engineering;for example,assessing the substrate promiscuity of ADS to chemoenzymatically produce *** this review,we discuss the discovery and catalytic mechanism of ADS,its application in metabolic engineering and synthetic biology,as well as the role of sesquiterpene synthases in the evolutionary origin of artemisinin.

关键词： Amorpha-4,11-diene Synthase Artemisinin Catalytic mechanism Metabolic engineering Synthetic biology

Fluorescence Microscopic Image Analysis of Nucleic Acids Based on The Capillary Flow Directed Assembly Ring of Neutral Red-nucleic Acid Supramolecular Complexes

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Chemical Research in Chinese Universities 2003年第3期19卷 275-279页

作者： LI Yuan fang huang Cheng zhi Laboratory of Supramolecular Chemistry and Biomedical Analysis College of Chemistry and Chemical EngineeringSouthwest Normal UniversityChongqing 400715P.R.China

It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.

关键词： Nuclei acids(NA) Neutral red(NR) Ring assembly Solid support surface Fluorescence imaging analysis

DOA Estimation Using Block Variational Sparse Bayesian Learning

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Chinese Journal of Electronics 2017年第4期26卷 768-772页

作者： huang Qinghua ZHANG Guangfei fang Yong Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai University

In Direction-of-arrival(DOA) estimation,the real-valued sparse Bayesian algorithm degrades the estimation performance by decomposing the complex value into real and imaginary components and combining them independently. We directly use complex probability density functions to model the noise and complex-valued sparse direction weights. Based on the Multiple measurement vectors(MMV), block sparse structure for the direction weights is integrated into the variational Bayesian learning to provide accurate source direction estimates. The proposed algorithm can be used for arbitrary array geometries and does not need the prior information of the incident signal number. Simulation results demonstrate the better performance of the proposed method compared with the real-valued sparse Bayesian algorithm, the Orthogonal matching pursuit(OMP) and l1 norm based complexvalued methods.

关键词： Direction-of-arrival estimation Varia tional Bayesian learning Sparse recovery Multiple mea surement vectors Block sparse structure

Farmers’risk preference and fertilizer use

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Journal of Integrative Agriculture 2021年第7期20卷 1987-1995页

作者： QIAO fang-bin huang Ji-kun China Economics and Management Academy Central University of Finance and EconomicsBeijing 100081P.R.China School of Advanced Agricultural Sciences Peking UniversityBeijing 100089P.R.China School of Economics and Management Jiangxi Agricultural UniversityNanchang 330045P.R.China

This study examines the role of farmers’risk attitudes toward fertilizer use in cotton production in *** previous studies,this paper theoretically shows that the relationship between farmers’risk aversion and fertilizer use is not always *** survey data were collected to test this relationship using the Cobb–Douglas production *** suggest that when the elasticity of fertilizer use and the probability of achieving the desired effects from fertilizer use are high,risk-averse farmers apply more fertilizer than risk-taking ***,when the elasticity of fertilizer use and the probability of achieving the desired effects are low,risk-taking farmers apply more fertilizer than risk-neutral or risk-averse farmers.

关键词： risk preferences fertilizer use farmers environment China

Layered photocatalytic nanomaterials for environmental applications

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Chinese Chemical Letters 2023年第3期34卷 24-38页

作者： fang Chen Yihe Zhang Hongwei huang Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of GeosciencesBeijing 100083China

The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research *** a “green” technology,semiconductor photocatalysis is of great significance to the environmental *** from the unique anisotropic crystal structure and electronic properties,layered photocatalytic nanomaterials show great potential for efficient photocatalytic environmental *** review comprehensively summarizes the recent progress on layered photocatalytic nanomaterials for oxidation or reduction of pollutants in water and air along with the basic understanding of related mechanisms and developments in this ***,the existing diversified layered photocatalysts are classified,and their different synthesis and modification strategies are discussed in detail to provide a comprehensive view of the material design that affects their photocatalytic ***,the extensive applications of the above-mentioned layered photocatalytic nanomaterials in environmental fields are systematically summarized,including photooxidation of water and air pollutants,and photoreduction of heavy metal pollutants,NO_(3)^(-),BrO_(3)^(-) and CO_(2).Finally,based on the current research achievements in layered photocatalysts for environmental remediation,the future development direction and challenges are proposed.

关键词： Layered photocatalytic nanomaterials Layered perovskite oxides Environmental applications Photocatalytic oxidation Photocatalytic reduction