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Characterization of a Purine Permease Family Gene OsPUP7 Involved in Growth and Development Control in Rice

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Journal of Integrative Plant Biology 2013年第11期55卷 1119-1135页

作者： Zhuyun qi Lizhong xiong National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan) Huazhong Agricultural University

In this study, PUP-type cytokinin transporter genes were identified in rice （Oryza sativa L.）. The Oryza sativa purine permease （OsPUP） family has 12 members that show similar predicted protein sequences with AtPUPs. To reveal the functions of OsPUP genes, we searched the T-DNA mutant library of rice and found one mutant for the member OsPUP7. The T-DNA insertion caused a new transcript that encodes a protein with 26 amino acids different from the native OsPUP7 at the C-terminus. The mutant showed multiple phenotypic changes including increased plant height, big seeds, and delayed flowering. The mutant also showed increased sensitivity to drought and salt stresses and treatments with kinetin and abscisic acid. OsPUP7is expressed mainly in the vascular bundle, pistil, and stamens. The measurement of cytokinins （CKs） showed that CK content in the mutant spikelets accumulated higher than that in the wild type. Moreover, uptake experiment in the yeast fcy2 mutant suggested that OsPUP7 has the ability to transport caffeine, a CK derivative. Our results indicate that the PUP transport system also exists in rice, and OsPUP7has an important role in the transport of CK, thus affecting developmental process and stress responses.

关键词： Abiotic stress cytokinin purine permease transporter rice.

An Example of Embedded Singular Continuous Spectrum for Discrete Schrödinger Operators

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1837-1849页

作者： Zheng qi FU xiong LI Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

We present an example of a potential such that the corresponding discrete Schrödinger operator has singular continuous spectrum embedded in the absolutely continuous spectrum.

关键词： Sparse potentials singular continuous spectrum Prüfer variables

Effect of warpage on the electronic structure and optical properties of bilayer germanene

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Journal of Semiconductors 2022年第12期43卷 39-45页

作者： qihang xiong Weifu Cen Xingtong Wu cong Chen College of Chemical Engineering Guizhou Minzu UniversityGuiyang 550025China College of Materials Science and Engineering Guizhou Minzu UniversityGuiyang 550025China College of Mechanical and Electrical Engineering Guizhou Minzu UniversityGuiyang 550025China

The electronic structure and optical properties of bilayer germanene under different warpages are studied by the first-principles method of density functional *** effects of warpages on the electronic structure and optical properties of bilayer germanene are *** results of the electronic structure study show that the bottom of the conduction band of bilayer germanene moves to the lower energy direction with the increase of warpages at the K point,and the top of the valence band stays constant at the K point,and so the band gap decreases with the increase of *** the warpage is 0.075 nm,the top of the valence band of bilayer germanene changes from K point to G point,and the bilayer germanene be-comes an indirect band gap *** is an effective means to modulate the conversion of bilayer germanene between direct band gap semiconductor and indirect band gap semiconductor by adjusting the band structure of bilayer ger-manene *** study of optical properties shows that the effect of warpage on the optical properties of bilayer ger-manene is mainly distributed in the ultraviolet and visible regions,and the warpage can effectively regulate the electronic struc-ture and optical properties of bilayer *** the warpage is 0.069 nm,the first peak of dielectric function and extinc-tion coefficient is the largest,and the energy corresponding to the absorption band edge is the ***,the elec-tron utilization rate is the best when the warpage is 0.069 nm.

关键词： bilayer germanene warpages electronic structure optical properties first-principles

Stereodivergent Synthesis of Carbocyclic Quaternary α-Amino Acid Derivatives Containing Two Contiguous Stereocenters

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Chinese Journal of Chemistry 2022年第9期40卷 1059-1065页

作者： cong Fu qi xiong Lu Xiao Ling He Tian Bai Zongpeng Zhang Xiu-qin Dong Chun-Jiang Wang Engineering Research Center of Organosilicon Compounds&Materials Ministry of EducationCollege of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei 430072China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 230021China Suzhou Institute of Wuhan University SuzhouJiangsu 215123China

A novel approach to stereodivergent synthesis of carbocyclicα-quaternary amino acid derivatives,bearing two contiguous stereocenters,is proposed through sequential dual Cu/Ir-catalyzed asymmetric allylation and ring-closing metathesis.A variety of five and six-membered carbocyclicα-quaternary amino acid derivatives could be readily achieved in good to high yields with exclusive regioselectivities,excellent diastereoselectivities(13:1->20:1 dr)and enantioselectivities(generally>99%ee).Of particular note is that the current protocol is also a versatile synthetic tool for the stereodivergent construction of the challenging seven and eight-membered carbocyclicα-amino acid *** four stereoisomers of these important molecules could be precisely synthesized through the permutation of chiral Cu/Ir catalytic *** power of this strategy has been demonstrated for the facile access to some biologically active chiral molecules,such as spiro-hydantoins.

关键词： Asymmetric catalysis Enantioselectivity Amino acids Allylation Metathesis

Automatic recognition of intersecting features of freeform sheet metal parts

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第10期10卷 1439-1449页

作者： Chun-jie ZHANG xiong-hui ZHOU cong-xin LI National Die and Mold CAD Engineering Research Center Shanghai Jiao Tong University Shanghai 200030 China

This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal *** developed methodology has three major steps:subdivision of B-spline surfaces,detection of protrusions and depressions,and recognition of geometric features for sheet metal forming *** input geometry data format of the part is based on an IGES CAD surface model represented in the form of trimmed B-spline *** surface is classified or subdivided into different curvature regions with the aid of curvature property surfaces obtained by using symbolic computation of B-spline *** regions satisfying a particular geometry and topology relation are recognized as protrusion and depression(DP) *** DP shapes are then classified into different geometric features using a rule-based approach.A verified feasibility study of the developed method is also presented.

关键词： Feature recognition (FR) Freeform surface Feature intersection Sheet metal forming

A New Random Forest Applied to Heavy Metal Risk Assessment

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Computer Systems Science & Engineering 2022年第1期40卷 207-221页

作者： Ziyan Yu cong Zhang Naixue xiong Fang Chen Wuhan Polytechnic University Department of Mathematics and Computer ScienceWuhan430023China Northeastern State University Department of Mathematics and Computer ScienceTahlequahOK74464USA

As soil heavy metal pollution is increasing year by year,the risk assess-ment of soil heavy metal pollution is gradually gaining *** heavy metal datasets are usually imbalanced datasets in which most of the samples are safe samples that are not contaminated with heavy *** Forest(RF)has strong generalization ability and is not easy to *** this paper,we improve the Bagging algorithm and simple voting method of ***-RF algorithm based on adaptive Bagging and weighted voting is proposed to improve the classifica-tion performance of RF on imbalanced *** Bagging enables trees in RF to learn information from the positive samples,and weighted voting method enables trees with superior performance to have higher voting ***-ments were conducted using G-mean,recall and F1-score to set weights,and the results obtained were better than *** assessment experiments were conducted using W-RF on the heavy metal dataset from agricultural fields around *** experimental results show that the RW-RF algorithm,which use recall to calculate the classifier weights,has the best classification *** the end of this paper,we optimized the hyperparameters of the RW-RF algorithm by a Bayesian optimization *** use G-mean as the objective function to obtain the opti-mal hyperparameter combination within the number of iterations.

关键词： Random forest imbalanced data Bayesian optimization risk assessment

Carbon isotopic compositions of mono-, di-, tri-aromatics provide insights into the source of sulfur-rich crude oils in the Huanghekou Depression, Bohai Bay Basin

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Petroleum Science 2023年第2期20卷 753-768页

作者： cong-Kai Niu Du-Jie Hou xiong Cheng Xu Han School of Energy Resources China University of GeosciencesBeijing100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism Ministry of EducationChina University of GeosciencesBeijing100083China

The stable carbon isotope compositions (δ13C) of individual aromatic hydrocarbons have been analyzed in sulfur-rich and sulfur-lean crude oils from the Huanghekou Depression, Bohai Bay Basin. The δ13C values of individual aromatic hydrocarbons, including alkylbenzenes, alkylnaphthalenes, alkylphenanthrenes, alkylfluorenes and alkyldibenzothiophenes, are reported. The main aims are to find out the origin of these oils and their relationship to paleoclimate. The distribution of aromatic hydrocarbons and maturity parameters show the oils all stay in the low-mature to mature stage. Meanwhile, aromatic hydrocarbons are mainly derived from the diagenetic/catagenetic origin. The δ13C values for 1,2,4-trimethylbenzene (−30.7‰ to −28.8‰) and 1,2,3,4-tetramethylbenzene (−32.4‰ to −26.3‰) indicate the algae-derived organic matter for alkylbenzenes. Some isomers, such as 1,7-+1,3-+1,6-dimethylnaphthalene, 1,2,5-trimethylnaphthalene, 1,2,5,6-+1,2,3,5-tetramethylnaphthalene, 1,10-+1,3-+3,10-+3,9-dimethylphenanthrenes, 1,6-+2,9-+2,5-dimethylphenanthrenes and 4,9-+4,10-+1,9- dimethylphenanthrenes show isotopic depletion (−34.9‰ to −25.2‰), indicating the major contribution of algae for these compounds. Meanwhile, isotopically depleted (−33.6‰ to −26.7‰) alkyldibenzothiophenes represent the algae input. δ13C values for mainly algae-derived naphthalene to trimethylnaphthalenes of sulfur-rich oils are more enriched than those of sulfur-lean oil, with the most significant difference of 4.4‰, indicating that the aridity of the environment and stratified water column result in the enrichment in 13C.

关键词： Carbon isotopes Aromatic hydrocarbons Sulfur-rich oils Huanghekou depression Bohai bay basin

Effect of morphological gene mutation and decay on energy dissipation behaviour of granular soils

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第4期24卷 303-318页

作者： Wei xiong qi-min ZHANG Jian-feng WANG Department of Architecture and Civil Engineering City University of Hong KongHong KongChina Shenzhen Research Institute of City University of Hong Kong Shenzhen 518057China

In this paper,the X-ray micro-computed tomography(X-rayμCT),spherical harmonical-based principal component analysis(SH-PCA),and discrete element method(DEM)were incorporated to generate virtual samples with morphological gene mutation at different length *** samples were subjected to axial compression and constant confining *** effects of multiscale particle morphology on the stress-strain and energy storage/dissipation responses of granular soils were *** is found that:(a)the effects of particle morphology on the initial stiffness,stress-strain,volumetric strain,and frictional energy dissipation behaviours are more pronounced for looser samples than for denser ones;(b)among different length scales,the particle morphology at the local roundness-level outperforms the one at the general form-level in dictating the macro-scale responses of granular soils;(c)the energy dissipation of a granular assemblage is a result of competition between particle morphology and initial void ratio.

关键词： X-ray micro-computed tomography(X-rayμCT) Spherical harmonic analysis(SHA) Discrete element method(DEM) Morphological gene mutation Energy dissipation

Solution of Terzaghi one-dimensional consolidation equation with general boundary conditions

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Journal of Central South University 2013年第8期20卷 2239-2244页

作者： MEI Guo-xiong CHEN qi-ming College of Transportation Engineering Nanjing University of Technology Nanjing 210009 China Louisiana Transportation Research Center Louisiana State University Baton Rouge 70808 USA

Boundary conditions for the classical solution of the Terzaghi one-dimensional consolidation equation conflict with the equation＇s initial condition. As such, the classical initial-boundary value problem for the Terzaghi one-dimensional consolidation equation is not well-posed. Moreover, the classical boundary conditions of the equation can only be applied to problems with either perfectly pervious or perfectly impervious boundaries. General boundary conditions are proposed to overcome these shortcomings and thus transfer the solution of the Terzaghi one-dimensional consolidation equation to a well-posed initial boundary value problem. The solution for proposed general boundary conditions is validated by comparing it to the classical solution. The actual field drainage conditions can be simulated by adjusting the values of parameters b and c given in the proposed general botmdary conditions. For relatively high coefficient of consolidation, just one term in series expansions is enough to obtain results with acceptable accuracy.

关键词： consolidation boundary condition pore water pressure consolidation degree