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On the Finite Basis Problem for Certain 2-limited Words

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Acta Mathematica Sinica,English Series 2013年第3期29卷 571-590页

作者： Jian Rong LI wen ting zhang yan feng luo Department of Mathematics Lanzhou University

Let X＊ be a free monoid over an alphabet X and W be a finite language over X. Let S（W） be the Rees quotient X＊/I（W）, where I（W） is the ideal of X＊ consisting of all elements of X＊ that are not subwords of W. Then S（W） is a finite monoid with zero and is called the discrete syntactic monoid of W. W is called finitely based if the monoid S（W） is finitely based. In this paper, we give some sufficient conditions for a monoid to be non-finitely based. Using these conditions and other results, we describe all finitely based 2-limited words over a three-element alphabet. Furthermore, an explicit algorithm is given to decide that whether or not a 2-limited word in which there are exactly two non-linear letters is finitely based.

关键词： Finite basis problem 2-limited words discrete syntactic monoid

非层状二维γ-In_(2)Se_(3)的各向异性生长及其光学特性

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原子与分子物理学报 2025年第6期42卷 58-65页

作者：雷子煊张文婷夏晓凤王红艳西南交通大学物理科学与技术学院材料先进技术重点实验室成都610031

非层状二维(2D)γ-In_(2)Se_(3)具有优异的光学和电学性能,在超薄柔性器件和光电探测领域具有广泛的应用前景.然而,相较于层状的类石墨烯材料,非层状材料固有的各向同性化学键,使得其二维各向异性生长面临较大的挑战.本研究构建了一种... 详细信息

非层状二维(2D)γ-In_(2)Se_(3)具有优异的光学和电学性能,在超薄柔性器件和光电探测领域具有广泛的应用前景.然而,相较于层状的类石墨烯材料,非层状材料固有的各向同性化学键,使得其二维各向异性生长面临较大的挑战.本研究构建了一种新的化学气相沉积(CVD)生长策略,成功制备了高质量的2Dγ-In_(2)Se_(3).首次选用低熔点的铟粉为前驱体,有效降低了生长温度.此外,生长过程去除了CVD法合成二维硒化物时不可避免的危险气体H_(2),这不仅能有效抑制InSe副产物的形成,还降低了实验危险性.通过探究原料用量、生长温度及时间等参数对样品形貌和厚度的影响,获得了最佳生长窗口.详细表征了2Dγ-In_(2)Se_(3)的微观形貌、化学组分、晶体结构和光学特性等.结果表明,样品具有强烈的光致发光(PL)效应,与γ-In_(2)Se_(3)的直接带隙属性相吻合.随着厚度的减小,PL峰会发生蓝移,说明光学带隙随之增大.Raman光谱显示,不同厚度的样品其特征峰也会发生移动,说明厚度会影响2Dγ-In_(2)Se_(3)的分子振动行为.由此可见,通过生长参数调控2Dγ-In_(2)Se_(3)的厚度,可实现对其光学带隙和分子振动行为的调控,这将为相关的理论研究和光电器件应用提供基本的材料平台.

关键词：非层状材料二维γ-In_(2)Se_(3) 化学气相沉积各向异性生长带隙

Mechanical characteristic and failure mechanism of joint with composite sucker rod

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Petroleum Science 2023年第5期20卷 3172-3183页

作者： yan-wen zhang Jia-Qi Che Han-Xiang Wang Jin zhang feng Li Ming-Chao Du Yu-ting Wang College of Mechanical and Electronic Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Petroleum Corporation Offshore Engineering(Qingdao)Company Limited Qingdao266520ShandongChina Technical Testing Center of SINOPEC Shengli Oilfield Co.Dongying257088ShandongChina College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao266590ShandongChina

Composite sucker rods are widely used in oil fields because of light weight,high strength,and corrosion *** technology becomes the primary connection method of ***,the joints with composite sucker rods are prone to debone and *** connected characteristics are less considered,so the failure mechanism of the joint is still *** on the cohesive zone model(CZM)and the Johnson-Cook constitutive model,a novel full-scale numerical model of the joint with composite sucker rod was established,and verified by pull-out *** mechanical properties and slip characteristics of the joint were studied,and the damaged procession of the joint was *** results showed that:a)the numerical model was in good agreement with the experimental results,and the error is within 5%;b)the von Mises stress,shear stress,and interface stress distributed symmetrically along the circumferential path increased gradually from the fixed end to the loading end;c)the first-bonded interface near the loading end was damaged at first,followed by debonding of the second-bonded interface,leading to the complete shear fracture of the epoxy,and resulted in the debonding of the joint with composite sucker rod,which can provide a theoretical basis for the structural design and optimization of the joint.

关键词： Joint with composite sucker rod Numerical model Connected characteristics Failure mechanism Tensile tests

RT-nPCR Assays for Amplification and Sequencing of VP1 Genes in Human Enterovirus A–D from Clinical Specimens

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Biomedical and Environmental Sciences 2020年第11期33卷 829-838页

作者： CHEN Wei wenG Yu Wei HE wen Xiang ZHU Ying YU ting ting XIE Jian feng ZHENG Kui Cheng yan yan Sheng zhang Yong Jun zhang wen Chang The School of Public Health Fujian Medical UniversityFuzhou 350122FujianChina Fujian Center for Disease Control and Prevention Fujian Provincial Key Laboratory of Zoonosis ResearchFuzhou 350001FujianChina

Objective To develop RT-nPCR assays for amplifying partial and complete VP1 genes of human enteroviruses(HEVs)from clinical samples and to contribute to etiological surveillance of HEV-related *** A panel of RT-nPCR assays,consisting of published combined primer pairs for VP1 genes of HEV A–C and in-house designed primers for HEV-D,was established in this *** sensitivity of each RT-nPCR assay was evaluated with serially diluted virus stocks of five serotypes expressed as CCID50 perμL and copies perμL,and the newly established methods were tested in clinical specimens collected in recent *** The sensitivity of RT-nPCR assays for amplifying partial VP1 gene of HEVs was 0.1 CCID50 perμL and 10 virus copies perμL,and for the complete VP1 gene was 1 CCID50 perμL and 100 virus copies perμL,using serially-diluted virus stocks of five *** a proof-of-concept,25 serotypes were identified and complete VP1 sequences of 23 serotypes were obtained by this system among 858 clinical specimens positive for HEVs during the past eight surveillance *** This RT-nPCR system is capable of amplifying the partial and complete VP1 gene of HEV A–D,providing rapid,sensitive,and reliable options for molecular typing and molecular epidemiology of HEVs in clinical specimens.

关键词： Clinical specimens Human enterovirus A–D VP1 gene Polymerase chain reaction

The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation

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Journal of Genetics and Genomics 2020年第9期47卷 497-512页

作者： Kegui zhang Meiping zhang Zhijun luo Zhili wen Xiaohua yan Department of Biochemistry and Molecular Biology School of Basic Medical SciencesNanchang UniversityNanchang330006China School of Biological Engineering Huainan Normal UniversityHuainan232001China School of Basic Medical Sciences Nanchang UniversityNanchang 330006China Department of Gastroenterology The Second Affiliated Hospital of Nanchang UniversityNanchang330006China Institute of Biomedical Sciences Nanchang University Medical CollegeNanchang330031

Hepatocellular carcinoma(HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor *** growth factor beta(TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple ***, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process.

关键词： TGF-β Hepatocellular carcinoma(HCC) Cell survival Proliferation Functional switch Signaling regulation

Gold-Catalyzed Direct Indolation of Tetrahydroisoquinolines

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Chinese Journal of Chemistry 2012年第12期30卷 2741-2746页

作者： zhang yan luo Sha feng Bainian Zhu Chengjian School of Medicine and Pharmaceutics Jiangnan University Wuxi diangsu 214122 China State Key Laboratry of Coordination Chemistrry School of Chemistry and Chemical Engieering Nanjing University Nanjing Jiangsu 210093 China

Nitrogen-containing heterocyclic compounds are important motifs of pharmaceuticals and functional materials, and there has been a growing interest in new synthetic methods for their preparations. In this paper, we report a direct cross-coupling reaction of indole with N-aryl tetrahydroisoquinolines in the presence of gold catalyst. The reaction is compatible with a wide range of substituted indoles, to enable the tbrmation of various alkylated heteroarenest, nder very mild reaction conditions.

关键词： C-H activation sp3 bonds indolation gold heterocyclic compounds

Influence of reaction of Al2O3 and carbonaceous materials in Al2O3–C refractories on aluminum and carbon pick-up of iron

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Journal of Iron and Steel Research International 2020年第1期27卷 55-61页

作者： Yao-wu Wei yan-jun Dong Tao zhang Jun-feng Chen wen yan The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Carbon-containing Al2O3 refractory crucibles and pure Al2O3 refractory crucible were fabricated to study the effect of carbon-containing Al2O3-C refractories on aluminum and carbon pick-up of *** crucibles with pure iron powder were placed in a vacuum induction furnace and heated at 1600℃ for regular time under flowing argon *** Al and C contents of iron samples were analyzed,and iron samples were also investigated using a field scanning electron microscope equipped with energy-dispersive *** results showed that carbon materials did affect the interac?tion of(Al2O3-C)/Fe system,carbothermal reduction in alumina occurred in the reaction system and the extent of reactions depended on the kinds of carbon materials.

关键词： Al2O3-C refractory Liquid iron Aluminum pick-up Carbon pick-up Carbothermal reduction

硫醇吸附挥发性有机气体(VOCs)的气敏机理

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原子与分子物理学报 2025年第3期42卷 35-44页

作者：张海燕李琦王梓臻文豪刘丹凤中国环境科学研究院北京100012 中国汽车工程研究院股份有限公司重庆401122 中国科学院微电子研究所北京100029

化学电阻气体传感器对于空气质量、食品检测和人体呼吸有着重要作用.传感器上修饰物硫醇与待测的VOCs之间吸附的气敏机理分析是选择硫醇、预测吸附能力与特异性的重要手段.本文选取了11-巯基-1-十一醇(MUD)和4-甲氧基苄硫醇(MTT)两种常... 详细信息

化学电阻气体传感器对于空气质量、食品检测和人体呼吸有着重要作用.传感器上修饰物硫醇与待测的VOCs之间吸附的气敏机理分析是选择硫醇、预测吸附能力与特异性的重要手段.本文选取了11-巯基-1-十一醇(MUD)和4-甲氧基苄硫醇(MTT)两种常见的硫醇与六种典型的VOCs(乙醇ETN、异丙醇IPA、丙酮ACN、正己烷HXN、甲苯TLN、苯甲醛BND),基于密度泛函理论(DFT),计算其表面静电势(ESP)并建立气体吸附模型.在气体吸附模型的基础上计算其吸附能,并分析其弱相互作用,从微观角度解释气体吸附的作用机理.实验结果表明,具有羟基的MUD分子对同样有羟基的气体(如ETN、IPA)能够以氢键的方式吸附,具有较强的选择效果;具有苯环的MTT分子与具有苯环结构的气体分子(如TLN、BND)吸附时会在苯环之间形成π-π堆积,基于色散作用进行吸附,这表明MTT分子对具有苯环结构的气体有着较强的吸附作用.研究发现其色散作用吸附的强弱与分子的表面ESP绝对值有关.本文对于传感器表面修饰物吸附气体的气敏机理进行了探究,并对表面修饰物的选择和实验结果预测提供了理论指导.

关键词：硫醇 VOCs DFT 表面静电势气体吸附模型弱相互作用分析

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Static shape control of a flat shell structure

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吉林大学学报（工学版） 2006年第B03期36卷 1-3页

作者： Yao Guo-feng zhang Lin-wen luo Zhi-jiu College of Mechanical Science and Engineering Jilin University Changchun 130022 China Jilin College of Traffic Profession Technique Changchun 130021 China

The eight-node and forty-DOF piezoelectric shell element were applied to shape control of a flat shell structure. By the direct and converse effects, a distributed piezoelectric sensor layer was used to monitor the shape deformation and a distributed actuator layer was used to suppresse the deflection. A finite element model was for static response of laminated shell with piezoelectric sensors/actuators was derived. The model was verified by calculating piezoelectric polymeric PVDF bimorph beam. The results are in good agreement with those obtained by theoretical analysis of Tzou and Hwang . A case study of the static shape control of a flat shell structure is presented.

关键词： piezoelectric shell element static shape control feedback control