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Single DnA Condensation Induced by Hexammine Cobalt with Molecular Combing

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Chinese Journal of Chemical Physics 2012年第3期25卷 359-364,374页

作者： Gao-ming Hu Yu Lin Shi-yong Ran Ya n-wei Wang Guang-can Yang College of Physics and Electronic Information Engineering Wenzhou University Wenzhou 325035 China

We investigated the interaction between DnA and hexammine cobalt III [Co（nH3）6]3＋ by a simple molecular combing method and dynamic light scattering. The average extension of A- DnA-YOYO-1 complex is found to be 20.9μm, about 30% longer than the contour length of the DnA in TE buffer （10 mmol/L Tris, 1 mmol/L EDTA, pH=8.0）, due to bis-intercalation of YOYO-1. A multivalent cation, hexammine cobalt, is used for DnA condensation. We find that the length of DnA-[Co（nH3）6]3＋ complexes decrease from 20.9 μm to 5.9μm as the concentration of the [Co（nH3）6]3＋ vary from 0 to 3 μmol/L. This observation provides a direct visualization of single DnA condensation induced by hexammine cobalt. The results from the molecular combing studies are supported by dynamic light scattering investigation, where the average hydrodynamic radius of the DnA complex decreases from 203.8 nm to 39.26 nm under the same conditions. It shows that the molecular combing method is feasible for quantitative conformation characterization of single bio-macromolecules.

关键词： Molecular combing Hexammine cobalt Condensation Dynamic light scatter-ing Fluorescent microscopy

Fast and Accurate Predictor-Corrector Methods Using Feedback-Accelerated Picard Iteration for Strongly nonlinear Problems

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1263-1294页

作者： Xuechuan Wang wei He Haoyang Feng Satya n.Atluri School of Astronautics Northwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering Texas Tech UniversityLubbock79409USA

Although predictor-corrector methods have been extensively applied,they might not meet the requirements of practical applications and engineering tasks,particularly when high accuracy and efficiency are necessary.A novel class of correctors based on feedback-accelerated Picard iteration(FAPI)is proposed to further enhance computational *** optimal feedback terms that do not require inversion of matrices,significantly faster convergence speed and higher numerical accuracy are achieved by these correctors compared with their counterparts;however,the computational complexities are comparably *** advantages enable nonlinear engineering problems to be solved quickly and accurately,even with rough initial guesses from elementary *** proposed method offers flexibility,enabling the use of the generated correctors for either bulk processing of collocation nodes in a domain or successive corrections of a single node in a finite difference *** our method,the functional formulas of FAPI are discretized into numerical forms using the collocation *** collocated iteration formulas can directly solve nonlinear problems,but they may require significant computational resources because of the manipulation of *** address this,the collocated iteration formulas are further converted into finite difference forms,enabling the design of lightweight predictor-corrector algorithms for real-time *** generality of the proposed method is illustrated by deriving new correctors for three commonly employed finite-difference approaches:the modified Euler approach,the Adams-Bashforth-Moulton approach,and the implicit Runge-Kutta ***,the updated approaches are tested in solving strongly nonlinear problems,including the Matthieu equation,the Duffing equation,and the low-earth-orbit tracking *** numerical findings confirm the computational accuracy and efficiency of the derived predictor-correc

关键词： Predictor-corrector method feedback-accelerated Picard iteration nonlinear dynamical system real-time computation

Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases

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World Journal of Gastroenterology 2024年第11期30卷 1524-1532页

作者： Yi-Fan Chang Jia-Jing Li Tao Liu Chong-Qing wei Li-wei Ma Vladimir n nikolenko wei-Long Chang Department of Gastrointestinal Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Pathology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Clinical Laboratory The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Human Anatomy and Histology I.M.Sechenov First Moscow State Medical University(Sechenov University)Moscow 119991Russia

Autophagy is a cellular catabolic process characterized by the formation of double-membrane *** electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and degradation.A large number of studies have shown that autophagy is closely related to the digestion,secretion,and regeneration of gastrointestinal(GI)***,the role of autophagy in GI diseases remains *** article focuses on the morphological and biochemical characteristics of autophagy in GI diseases,in order to provide new ideas for their diagnosis and treatment.

关键词： Autophagy Morphological study Biochemical characteristics Subcellular structure Transmission electron microscopy Gastrointestinal diseases

FRACTURE RESISTAnCE OF 3D-C/SiC COMPOSITES AT 1300℃

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 437-442页

作者： G.C.Ji S.R.Qiao S.M.Du M.Li D.Han J.n.wei College of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072China Material Engineering Department Jiujiang College Jiujiang 332005 ChinaCollege of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072ChinaMaterial Engineering Department Xi'an Science and Technical University Xi'an 710060 ChinaCollege of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072ChinaCollege of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072ChinaMaterial Engineering Department Jiujiang College Jiujiang 332005 China

Based on the energy conservation, the elastic energy linked to the compliance change, non-elastic energy dissipated by irreversible deformation and the resistance for crack propagation were quantitatively characterized by evaluation the load/load point displacement curves tested by three points bend experiment with single notch beam at 1300℃. The cracks length was determined by compliance calibration curves. It is shown by experimental results that the compliance of 3D-C/SiC composites changes with the cracks can be described by third order polynomial. The variation of crack advancing resistance with non-dimensional equivalent crack length presents a convex curve. The crack advancing resistance increases firstly and then decreases with the non-dimensional equivalent crack length, finally is in comparatively low level. The maximum values of crack advancing resistance are 269.73kJ/m2 for non-dimensional equivalent crack length of 0.318 and original notch length of 0.35mm, and 138.65kJ/m2 for non-dimensional equivalent crack length of 0.381 and original notch length of 2.06mm, respectively.

关键词： fracture resistance 3D-C/SiC energy conservation

维普期刊数据库

Changes of Soluble Protein, Peroxidase Activity and Distribution During Regeneration After Girdling in Eucommia ulmoides

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Acta Botanica Sinica 2004年第2期46卷 216-223页

作者： HOUHong-wei Kalima-n＇KomaMWAnGE WAnGYa-Qing CUIKe-Ming CollegeofLifeSciences PekingUniversityBeijing100871China

Peroxidases are known to play important roles in plant wound healing. Biochemical analysisand histochemical localization techniques were used to assess changes and distribution of peroxidases inthe recovering bark after girdling in Eucommia ulmoides Oliv. Between 4 and 21 days after girdling (DAG),peroxidases activity in the girdled trees significantly increased by 30-40 times over that in ungirdled *** the whole bark recovery process (from 0 to 63 DAG), the peroxidase signal was not found in thetissue regions subjected to intense cell division activity (regenerating cambial zone and phellogen). However,high peroxidase activity was detected in the callus, cortex-like, mature phloem and xylem. Interestingly, itwas shown that, in maturing xylem and phloem cells, there was respectively an inward and outwardperoxidase activity gradient on both sides of the cambium zone. An isoelectric-focusing electrophoresis ofthe extracted protein displayed two isozyme bands of peroxidase: POD Ⅰ and POD Ⅱ. POD Ⅰ was onlydetected in the xylem fraction and could play a role in xylem differentiation. POD Ⅱ was only identified inthe recovering bark portion and could be more engaged in bark regeneration process. A relationshipbetween IAA and peroxidase is also discussed.

关键词：过氧化物酶形成层杜仲剥皮再生同工酶

OnFractional(g,f,n′,m)-Critical Covered Graphs

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Journal of the Operations Research Society of China 2024年第2期12卷 446-460页

作者： wei Gao wei-Fan Wang School of Information Science and Technology Yunnan Normal UniversityKunming 650500YunnanChina Department of Mathematics Zhejiang Normal UniversityJinhua 321004ZhejiangChina

The main contribution in this article is threefold:(1)we show the necessary and sufficient condition for graphs to be fractional(g,f)-covered which can be expressed in different forms,and extended to fractional(g,f,m)-covered graphs;(2)the concept of fractional-critical covered graph is put forward and its necessary and sufficient condition is given;(3)we present the degree condition for a graph to be fractional(g,f,n′,m)-critical covered,and show that degree bound is sharp when m is ***,the related result in fractional(a,b,n′,m)-critical covered setting is also verified.

关键词： network Fractional factor Data transmission Fractional covered graph Fractional critical covered graph

nitric oxide assists nitrogen reduction reaction on 2D MBene: A theoretical study

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Chinese Chemical Letters 2024年第5期35卷 428-433页

作者： Chaozheng He Jia Wang Ling Fu wei wei Henan Engineering Center of new Energy Battery Materials College of Chemistry and Chemical EngineeringShangqiu Normal UniversityShangqiu 476000China School of Chemistry and Chemical Engineering Shandong Provincial Key Laboratory/Collaborative Innovation Center of Chemical Energy Storage&Novel Cell TechnologyLiaocheng UniversityLiaocheng 252059China Institute of Environment and Energy Catalysis Shaanxi Key Laboratory of Optoelectronic Functional Materials and DevicesSchool of Materials Science and Chemical EngineeringXi’an Technological UniversityXi’an 710021China College of Resources and Environmental Engineering Tianshui Normal UniversityTianshui 741001China

Electrocatalytic synthesis of ammonia as an environment-friendly and sustainable development method has received widespread attention in recent ***-dimensional(2D)materials are a promising catalyst for ammonia synthesis due to their large surface *** this work,we have constructed a series of 2D metal borides(MBenes)with transition metal(TM)defects(TMd-MBenes)and comprehensively calculated the reactivity of electrocatalytic synthesis of ammonia-based on density functional *** results have demonstrated that the TMd-MBenes can effectively activate nitrogen oxide(nO)and nitrogen(n2)molecules *** interesting,the co-chemisorption of O atoms,dissociated from nO,can facilitate the spilled of the inert n2 molecules into single n atoms,which can further hydrogenate into ammonia easily with an ultralow limiting potential of 0.59 V on *** research has not only provided clues for catalyst design for experimental study but also paved the way for the industrial application of electrocatalytic ammonia synthesis.

关键词： 2D mbenes nitrogen electro-reduction DFT n_(2)activation Ammonia synthesis

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Improved Approximation Schemes for Early Work Scheduling on Identical Parallel Machines with a Common Due Date

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Journal of the Operations Research Society of China 2024年第2期12卷 341-350页

作者： wei-Dong Li School of Mathematics and Statistics Yunnan UniversityKunming650504YunnanChina

We study the early work scheduling problem on identical parallel machines in order to maximize the total early work,i.e.,the parts of non-preemptive jobs that are executed before a common due *** preprocessing and constructing an auxiliary instance which has several good properties,for any desired accuracy,we propose an efficient polynomial time approximation scheme with running time O(f(1/ε)n),where n is the number of jobs and f(1/ε)is exponential in 1/ε,and a fully polynomial time approximation scheme with running time O(1/ε^(2m+1)+n)when the number of machines is fixed.

关键词： Scheduling Early work Polynomial time approximation scheme Effcient polynomial time approximation scheme Fully polynomial time approximation scheme

Recent progress on the functionalization of white phosphorus in China

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national Science Review 2024年第6期11卷 308-320页

作者： Xinlei Huangfu Zhongzhen Wang Yu Chen Junnian wei wei Liu Wen-Xiong Zhang Beijing national Laboratory for Molecular Sciences(BnLMS) State Key Laboratory of Rare-Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular Engineering Peking University

Direct synthesis of organophosphorus compounds from white phosphorus represents a significant but challenging subject, especially in the context of ongoing efforts to comprehensively improve the phosphorus-derived chemical industry driven by sustainability and safety concerns. China is the world's largest producer of white phosphorus, creating a significant demand for the green transformation of this crucial feedstock. This review provides an overview of advancements in white phosphorus activation by Chinese research teams, focusing on the direct construction of P–C/n/O/S/M bonds from white phosphorus. Additionally, we offer some insights into prospective directions for the activation and transformation of white phosphorus in the future. This review paper aims to attract more researchers to engage in this area, stimulating follow-up exploration and fostering enduring advances.

关键词： white phosphorus organophosphorus compound activation selectivity efficiency