检索结果-南通市图书馆

Bandwidth adaption for kernel particle filter

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2011年第2期22卷 340-346页

作者： Fu li Guangming shi Fei Qi li Zhang School of Electronic Engineering Xidian University Xi'an 710071 P. R. China

A novel particle filter bandwidth adaption for kernel particle filter （BAKPF） is proposed. Selection of the kernel bandwidth is a critical issue in kernel density estimation （KDE）. The plug-in method is adopted to get the global fixed bandwidth by optimizing the asymptotic mean integrated squared error （AMISE） firstly. Then, particle-driven bandwidth selection is invoked in the KDE. To get a more effective allocation of the particles, the KDE with adap- tive bandwidth in the BAKPF is used to approximate the posterior probability density function （PDF） by moving particles toward the posterior. A closed-form expression of the true distribution is given. The simulation results show that the proposed BAKPF performs better than the standard particle filter （PF）, unscented particle filter （UPF） and the kernel particle filter （KPF） both in efficiency and estimation precision.

关键词： kernel density estimation adaptive bandwidth kernel,particle filter.

Immobilization of TiO_2 nanoparticles on activated carbon fiber and its photodegradation performance for organic pollutants

在线全文

学校读者我要写书评

暂无评论

Particuology 2010年第3期8卷 272-278页

作者： Shuhua Yao Jinyang li Zhongliang shi Department of Applied Chemistry Shenyang Institute of Chemical Technology Shenyang 110142 China

The immobilization of titanium dioxide （TiO2） on activated carbon fiber （ACF）, （TiO2/ACF）, was accomplished by sol-gel-adsorption method followed by calcination at temperatures varying from 300 to 600℃ in an argon atmosphere. The material properties were determined by scanning electron microscope （SEM）, X-ray diffraction （XRD） and nitrogen adsorption. The photodegradation behavior of TiO2 /ACF was investigated in aqueous solutions using phenol and methyl orange （MO） as target pollutants. The effects of calcination temperature, photocatalyst dosage, initial solution pH and radiation time on the degradation of organic pollutants were studied. It was found that organic pollutants could be removed rapidly from water by the TiO2/ACF photocatalyst and the sample calcined at 500℃ exhibited the highest removal efficiency. Kinetics analysis showed that the photocatalytic degradation reaction can be described by a first-order rate equation. In addition, the possibility of cyclic usage of the photocatalyst was also confirmed. Moreover, TiO2 is tightly bound to ACF and can be easily handled and recovered from water. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.

关键词： Titanium dioxide Activated carbon fiber Photocatalytic degradation Phenol MO

A novel method to anchor methanesulfonic acid in silica matrix

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2016年第3期59卷 370-379页

作者： Naiwang liu Jiajia Yao li shi State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

Methanesulfonic acid （MSA） was successfully immobilized in silica, leading to a novel and environmentally friendly solid acid catalyst SMSA. The most important feature of SMSA is that anhydrous formic acid is used to hydrolysis of tetraethylorthosili- cate （TEOS）. No water was added in the whole preparation. Therefore, MSA could be anchored in silica matrix more effec- tively instead of being dissolved in water. This new organic/inorganic hybrid catalyst was characterized by powder X-ray dif- fraction （XRD）, energy dispersive spectrum （EDS）, N2 adsorption-desorption analyzer, thermogravimetric analysis （TGA-DSC） and pyridine-FTIR. The catalytic activity was tested by alkylation of olefins and aromatics. High concentration acid sites, both Lewis and Brcnsted, abundant porosity and large surface area enabled the highest activity for SMSA, among MCM-22. ZSM-5 and industrial acidity clay.

关键词： methanesulfonic acid olefin removal solid acid catalyst alkylation

A novel preparation method of sulfonic functionalized silica： CH3SO3H as the sulfonic source and Al as the bridge

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2016年第3期59卷 264-270页

作者： Naiwang liu Jiajia Yao li shi The State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silica matrix. Further pyridine-FTIR spectra followed by catalytic activity tests demonstrate that compared with previous methods, our new approach results in higher Lewis acid site concentration, higher thermal stability and superior catalytic activity. Moreover, the whole catalysis preparation procedure is environmentally friendly. Specifically, the silica matrix is synthesized through hydrolysis of tetrae- thylorthosilicate employing formic acid as hydro-catalyst, in which no surfactant species or precursors were involved.

关键词： methanesulfonic acid silica sulfonation solid super-acid catalyst

Cycloartane triterpenoid and its glucoside isolated from Cassia occidentalis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2017年第12期15卷 950-954页

作者： li shi-Fei li Shun-lin Institute of Molecular Science Shanxi University State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences

In the present study, one new cycloartane triterpenoid, named cycloccidentalic acid C(1) and its glucoside, cycloccidentaliside VI(2) were isolated from the whole plant of Cassia occidentalis. Their structures were elucidated by a combinational analyses of 1D and 2D NMR data and HRMS. Compound 2 showed modest anti-HIV-1 activity with EC_(50) value of 1.44 μmol·L^(-1) and TI(Therapeutic Index) value of 15.59.

关键词： Cycloartane triterpenoid Cassia occidentalis Cycloccidentalic acid C Cycloccidentaliside Ⅵ

Catalytic conversion of cellulose-based biomass and glycerol to lactic acid

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第5期28卷 138-151页

作者： shi li Weiping Deng Yanyun li Qinghong Zhang Ye Wang State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials National Engineering Laboratory for Green Chemical Productions of Alcohols Ethers and Esters College of Chemistry and Chemical Engineering Xiamen University

Catalytic transformation of cellulose into value-added chemicals is of great importance for utilization of renewable and abundant biomass. Due to the high oxygen content, cellulose serves as an ideal candidate for the production of oxygenates, in particular lactic acid which is a versatile building block in chemical industry. The efficient conversion of cellulose to lactic acid generally requires selective activation of specific C-O and C-C bonds, and therefore multifunctional catalysts that combine several key reactions including hydrolysis, isomerization and retro-aldol fragmentation are highly desirable. This review article highlights the recently developed catalytic systems and catalysts for the selective transformation of cellulose and cellulose-derived carbohydrates into lactic acid, lactates and/or its esters. Emphases will be put on the reaction mechanism and key factors that exert effects on the catalytic performances. In addition, the catalytic transformation of glycerol, a C3 compound over-supplied from biodiesel industry, will also be surveyed. Recent advances in the development of new catalysts or strategies are analyzed and discussed to gain insight into the transformation of C3 compound to lactic acid.

关键词： Cellulose Glycerol Lactic acid Multifunctional catalysis

Systematic identification and functional analysis of long noncoding RNAs involved in indoxacarb resistance in Spodoptera litura

在线全文

学校读者我要写书评

暂无评论

Insect Science 2022年第6期29卷 1721-1736页

作者： li shi Wen-lin li Hai-Xin Zeng Yao shi Xiao-Lan liao Hunan Provincial Engineering and Technology Research Center for Bio-pesticide and Formulation Processing College of Plant ProtectionHunan Agricultural UniversityChangshaChina Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases andInsectPests ChangshaChina

Long noncoding RNAs(lncRNAs)are noncoding transcripts that are more than 200 nucleotides *** play essential roles in regulating a variety of biological processes in many species,including insects,and some lncRNAs have been found to be associated with insecticide ***,the characteristics and biological func-tions of lncRNAs involved in indoxacarb resistance are unknown in Spodoptera *** performed RNA sequencing in the SS,InRS,and FInRS of *** and identified 11978 lncRNAs,including 3136 intergenic lncRNAs,7393 intronic lncRNAs,and 1449 anti-sense *** with the SS,51 lncRNAs were upregulated and 134 lncRNAs were downregulated in the two resistant strains,and 908 differentially expressed mRNAs were predicted as the target genes of the 185 differentially expressed *** analysis showed that 112 of differentially expressed lncRNAs may be associated with in-doxacarb resistance by regulating the expression of 14 P450s,seven CCEs,one GST,six UGTs,five ABC transporters,and 24 cuticle protein genes,and 79 of differentially ex-pressed lncRNAs may regulate the expression of 14 detoxification genes and 19 cuticle protein genes to participate in indoxacarb resistance by sponging 10 ***-ingly,47 of differentially expressed lncRNAs may mediate indoxacarb resistance through both lncRNA-mRNA and lncRNA-miRNA-mRNA regulatory ***,quantitative PCR,RNA interference,and indoxacarb bioassay analyses indicated that over-expressed LNC_004867 and LNC_006576 were involved in indoxacarb *** study provides comprehensive information for lncRNAs of ***,and presents evidence that lncRNAs havekey roles in conferring insecticide resistance in ***.

关键词： indoxacarb resistance long noncoding RNAs regulatory pathways RNA sequencing Spodopteralitura

The First Disease X is Caused by a Highly Transmissible Acute Respiratory Syndrome Coronavirus

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2020年第3期35卷 263-265页

作者： shibo Jiang Zheng-li shi Key Laboratory of Medical Molecular Virology(MOE/NHC/CAMS) School of Basic Medical SciencesFudan UniversityShanghai 200032China New York Blood Center The Lindsley F.Kimball Research InstituteNew YorkNY 10065USA CAS Key Laboratory of Special Pathogens Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan 430071China

Based on the announcement of the World Health Organization(WHO) in 2018, the Wuhan pneumonia caused by an unknown etiology should be recognized as the first Disease X. Later, the pathogen was identified to be a novel coronavirus denoted 2019-nCoV, which has 79.5% and 96% whole genome sequence identify to SARS-CoV and bat SARS-related coronavirus(SARSr-CoV-RaTG13), respectively, suggesting its potential bat origin. With high human-to-human transmission rate(R0), 2019-nCoV has quickly spread in China and other countries, resulting in 34,953 confirmed cases and 725 deaths as of 8 February 2020, thus calling for urgent development of therapeutics and prophylactics. Here we suggest renaming 2019-nCoV as "transmissible acute respiratory syndrome coronavirus(TARS-CoV)" and briefly review the advancement of research and development of neutralizing antibodies and vaccines targeting the receptor-binding domain(RBD) and viral fusion inhibitors targeting the heptad repeat 1(HR1) domain in spike protein of 2019-nCoV.

关键词： Coronavirus 2019-nCoV SARS-CoV Pneumonia Acute respiratory syndrome Disease X

A mathematical model for column leaching of ion adsorption-type rare earth ores

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 463-471页

作者： Ping Long Guan-shi Wang Shuo Zhang shi-li Hu Ying Huang School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Cooperative Innovation Center of Efficient Development and Application for Ionic Rare Earth Resources Jiangxi University of Science and TechnologyGanzhou341000China School of Architectural and Surveying and Mapping Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

Column leaching experiments with ion adsorption-type rare earth ores for different lixiviant concentrations and different column heights were carried out.A mathematical model of column leaching was constructed based on the experimental *** parameters(a and b)in the model were determined according to the following methodology:the ore column was divided into several units;each unit was treated with multiple leaching *** leaching process was simulated as a series of batch leaching *** a of the model was determined based on the selectivity coefficient of the balanced batch leaching ***,the influences of ammonium sulfate concentration,rare earth grade,column height,permeability coefficient,and hydrodynamic dispersion coefficient on the extraction were *** between parameter b,the ammonium sulfate concentration,and the physical and mechanical properties of the ore column,were examined using dimensional *** was determined that the optimal ammonium sulfate concentration for different column heights(2.5,5.0,7.5,and 10.0 cm)using the mathematical model were 5.9,6.2,7.3,and 7.7 g/L,*** mathematical model can be used to estimate the breakthrough curve,leaching rate,and leaching period of rare earth ores,to achieve optimal extraction.

关键词： ion adsorption-type rare earth ores extraction ore leaching period concentration optimization