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Chinese Annals of Mathematics,Series B 2017年第2期38卷 601-628页

作者： Hoai-Minh nguyen EPFL SB MATHAA CAMA Station 8CH-1015 LausanneSwitzerland

Negative index materials are artificial structures whose refractive index has negative value over some frequency range. These materials were first investigated theoretically by Veselago in 1946 and were confirmed experimentally by Shelby, Smith, and Schultz in2001. Mathematically, the study of negative index materials faces two difficulties. Firstly,the equations describing the phenomenon have sign changing coefficients, hence the ellipticity and the compactness are lost in general. Secondly, the localized resonance, i.e.,the field explodes in some regions and remains bounded in some others as the loss goes to 0, might appear. In this survey, the author discusses recent mathematics progress in understanding properties of negative index materials and their applications. The topics are reflecting complementary media, superlensing and cloaking by using complementary media, cloaking a source via anomalous localized resonance, the limiting absorption principle and the well-posedness of the Helmholtz equation with sign changing coefficients.

关键词： Negative index materials, Localized resonance, Cloaking, Superlensing

A Hybrid Grey DEMATEL and PLS-SEM Model to Investigate COVID-19 Vaccination Intention

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Computers, Materials & Continua 2022年第9期72卷 5059-5078页

作者： Phi-Hung nguyen Department of Business Management National Taipei University of TechnologyTaipei10608Taiwan Faculty of Business FPT UniversityHanoi100000Vietnam

The main objective of this study is to comprehensively investigate individuals’vaccination intention against COVID-19 during the second wave of COVID-19 spread in Vietnam using a novel hybrid ***,the Decision-Making Trial and Evaluation Laboratory based on Grey Theory(DEMATEL-G)was employed to explore the critical factors of vaccination intention among ***,Partial Least Squares-Structural Equation Modeling(PLS-SEM)was applied to test the hypotheses of individual behavioral intention to get the vaccine to prevent the outbreak of COVID-19.A panel of 661 valid respondents was collected from June 2021 to July 2021,and confidentiality was maintained for all data *** results identified that perception of COVID-19 vaccination and trust in vaccination strategy directly associated with individuals’COVID-19 ***,the perceived severity of COVID-19 has an indirect impact on COVID-19 vaccination intentions via the perception of the COVID-19 *** findings indicated that the government’s information about vaccines is necessary for the new phase of vaccination intervention strategies in ***,the study suggests that the government needs to give complete information about the role of vaccines prioritizes transparency in official information about COVID-19 vaccines to allay concerns about side effects,allowing for the most appropriate policy formulation and implementation to encourage public *** studies can apply PLS-SEM and other MCDM models with the fuzzy,hesitant numbers to re-evaluate the feasibility,validity and reliability of this research’s proposed model.

关键词： COVID-19 vaccination immunization intervention PLS-SEM DEMATEL grey theory vietnam

Isogeometric analysis for free vibration of bidirectional functionally graded plates in the fluid medium

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Defence Technology（防务技术） 2022年第8期18卷 1311-1329页

作者： Quoc-Hoa Pham Phu-Cuong nguyen Van Ke Tran Trung nguyen-Thoi Faculty of Civil Engineering Ho Chi Minh City Open UniversityHo Chi Minh CityViet Nam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoiViet Nam Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam

This paper for first time proposes an isogeometric analysis (IGA) for free vibration response of bi-directional functionally graded (BDFG) rectangular plates in the fluid medium. Material properties of the BDFG plate change in both the thickness and length directions via power-law distributions and Mori-Tanaka model. The governing equation of motion of BDFG plate in the fluid-plate system is formulated basing on Hamilton's principle and the refined quasi three-dimensional (3D) plate theory with improved function f(z). The fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to determine the added mass. The discrete system of equations is derived from the Galerkin weak form and numerically analyzed by IGA. The accuracy and reliability of the proposed solutions are verified by comparing the obtained results with those published in the literature. Moreover, the effects of the various parameters such as the interaction boundary condition, geometric parameter, submerged depth of plate, fluid density, fluid level, and the material volume control coefficients on the free vibration behavior of BDFG plate in the fluid medium are investigated in detail. Some major findings regarding the numerical results are withdrawn in conclusions.

关键词： Contact plate-fluid Refined quasi 3D plate theory Mori-Tanaka model Isogeometric analysis Bidirectional functionally graded plate

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糯玉米品种斯达糯46在越南的试种表现

现代农业科技 2024年第11期 19-23,27页

作者：章忠贵朱守晶 nguyen Pham Hung DANG Cao Cuong 江明山李新燕华中农业大学湖北武汉430070 安徽科技学院农学院安徽凤阳233100 越南太平种子股份公司越南太平33000 北京中农斯达农业科技开发有限公司北京101500

为明确糯玉米优质品种斯达糯46在越南种植的适应性,将该品种种植于越南红河三角洲地区,以越南主栽品种HN88为对照,对其生育期、农艺性状、抗性、食味品质等进行鉴定和评价。结果表明,斯达糯46生育进程与对照HN88相似;农艺性状方面,斯达... 详细信息

为明确糯玉米优质品种斯达糯46在越南种植的适应性,将该品种种植于越南红河三角洲地区,以越南主栽品种HN88为对照,对其生育期、农艺性状、抗性、食味品质等进行鉴定和评价。结果表明,斯达糯46生育进程与对照HN88相似;农艺性状方面,斯达糯46穗位株高比优于对照HN88,抗倒伏能力强;抗病虫害方面,斯达糯46对螟虫、大斑病、小斑病、茎腐病、矮花叶病、穗腐病有良好的抗性;果穗性状方面,斯达糯46的双穗率、穗长、穗粗、穗行数、穗粒数均高于对照HN88,千粒重较对照HN88高13.3%;产量表现方面,斯达糯46的鲜穗产量较对照HN88显著增加20.9%,籽粒产量较对照HN88增加17.8%;品质评分与对照HN88接近。综合以上结果,种植于越南的斯达糯46表现了良好的气候适应性,在产量、抗性、品质、植株性状等方面表现突出,有良好的推广价值。

关键词：糯玉米斯达糯46 产量适应性越南

Asymptotic Expansions of Backward Equations for Two-time-scale Markov Chains in Continuous Time

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Acta Mathematicae Applicatae Sinica 2009年第3期25卷 457-476页

作者： Dung Tien nguyen Department of Mathematics Wayne State University

This work develops asymptotic expansions for solutions of systems of backward equations of time- inhomogeneous Maxkov chains in continuous time. Owing to the rapid progress in technology and the increasing complexity in modeling, the underlying Maxkov chains often have large state spaces, which make the computa- tional tasks ihfeasible. To reduce the complexity, two-time-scale formulations are used. By introducing a small parameter ε〉 0 and using suitable decomposition and aggregation procedures, it is formulated as a singular perturbation problem. Both Markov chains having recurrent states only and Maxkov chains including also tran- sient states are treated. Under certain weak irreducibility and smoothness conditions of the generators, the desired asymptotic expansions axe constructed. Then error bounds are obtained.

关键词： Markov chain backward equation two-time scale asymptotic expansion

Non-Negative Adaptive Mechanism-Based Sliding Mode Control for Parallel Manipulators with Uncertainties

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Computers, Materials & Continua 2023年第2期74卷 2771-2787页

作者： Van-Truong nguyen Department of Mechatronics Engineering Hanoi University of IndustryHanoi159999Vietnam

In this paper,a non-negative adaptive mechanism based on an adaptive nonsingular fast terminal sliding mode control strategy is proposed to have finite time and high-speed trajectory tracking for parallel manipulators with the existence of unknown bounded complex uncertainties and external *** proposed approach is a hybrid scheme of the online non-negative adaptive mechanism,tracking differentiator,and nonsingular fast terminal sliding mode control(NFTSMC).Based on the online non-negative adaptive mechanism,the proposed control can remove the assumption that the uncertainties and disturbances must be bounded for the NFTSMC *** proposed controller has several advantages such as simple structure,easy implementation,rapid response,chattering-free,high precision,robustness,singularity avoidance,and finite-time *** all control parameters are online updated via tracking differentiator and non-negative adaptive law,the tracking control performance at high-speed motions can be better in real-time requirement and disturbance rejection ***,simulation results validate the effectiveness of the proposed method.

关键词： Parallel manipulator uncertainties and disturbances nonsingular fast terminal sliding mode control non-negative adaptive mechanism tracking differentiator

NORMAL FAMILY OF MEROMORPHIC FUNCTIONS SHARING HOLOMORPHIC FUNCTIONS AND THE CONVERSE OF THE BLOCH PRINCIPLE

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Acta Mathematica Scientia 2017年第3期37卷 623-656页

作者： nguyen Van THIN Department of Mathematics Thai Nguyen University of EducationLuong Ngoc Quyen StreetThai Nguyen cityThai NguyenViet Nam

In 1996, C. C. Yang and P. C. Hu [8] showed that： Let f be a transcendental meromorphic function on the complex plane, and a ≠ 0 be a complex number; then assume that n 〉 2, n1,… , nk are nonnegative integers such that n1＋… ＋ nk ≥1; thus fn（f′）n1…（f（k））nk-a has infinitely zeros. The aim of this article is to study the value distribution of differential polynomial, which is an extension of the result of Yang and Hu for small function and all zeros of f having multiplicity at least k ≥2. Namely, we prove that fn（f′）n1…（f（k））nk-a（z） has infinitely zeros, where f is a transcendental meromorphic function on the complex plane whose all zeros have multiplicity at least k≥ 2, and a（z） 0 is a small function of f and n ≥ 2, n1,… ,nk are nonnegative integers satisfying n1＋ …＋ nk ≥1. Using it, we establish some normality criterias for a family of meromorphic functions under a condition where differential polynomials generated by the members of the family share a holomorphic function with zero points. The results of this article are supplement of some problems studied by d. Yunbo and G. Zongsheng [6], and extension of some problems studied X. Wu and Y. Xu [10]. The main result of this article also leads to a counterexample to the converse of Bloeh＇s principle.

关键词： Normal family Nevanlinna theory meromorphic function sharing function differential pOlynomial

Distinguishing between parenchymal and anastomotic leakage at duct-to-mucosa pancreatic reconstruction in pancreaticoduodenectomy

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World Journal of Gastroenterology 2008年第43期14卷 6648-6654页

作者： Justin H nguyen Division of Transplant Surgery Department of TransplantationMayo ClinicJacksonvilleFlorida 32224United States

AIM： To distinguish anastomotic from parenchymal leakage at duct-to-mucosa reconstruction of the pancreatic remnant. METHODS： We reviewed the charts of 68 pancreaticoduodenectomies performed between 5/2000 and 12/2005 with end-to-side duct-to-mucosa pancreatojejunostomy （PJ）. The results of pancreatography, as well as peripancreatic drain volumes, and amylase levels were analyzed. RESULTS： Of 68 pancreatojejunostomies, 48 had no leak by pancreatography and had low-drain amylase （normal）; eight had no pancreatographic leak but had elevated drain amylase （parenchymal leak）; and 12 had pancreatographic leak and elevated drain amylase （anastomotic leak）. Although drain volumes in the parenchymal leak group were significantly elevated at postoperative day （POD） 4, no difference was found at POD 7. Drain amylase level was not significantly different at POD 4. In contrast, at POD 7, the anastomotic-leak group had significantly elevated drain amylase level compared with normal and parenchymalleak groups （14158 ＋ 24083 IU/L vs 89 ＋ 139 IU/L and 1707 ＋ 1515 IU/L, respectively, P = 0.012）. CONCLUSION： For pancreatic remnant reconstruction after pancreaticoduodenectomy, a combination of pancreatogram and peripancreatic drain amylase levels can be used to distinguish between parenchymal and anastomotic leakage at pancreatic remnant reconstruction.

关键词： Anastomotic leak Pancreatic leak Pancreaticoduodenectomy Pancreatogram Whipple procedure

Complexities and pitfalls in analyzing and interpreting mitochondrial DNA content in human cancer

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Journal of Genetics and Genomics 2020年第7期47卷 349-359页

作者： Hieu nguyen Thomas LaFramboise Vinmec Research Institute of Stem Cell and Gene Technology(VRSIG) 458 M inh KhaiVinh TuyHai Ba TrungHanoiViet Nam Department of Genetics and Genome Sciences Case Western Reserve University School of Medicine10900 Euclid AvenueClevelandOH44106USA

Mutations in the human mitochondrial genome have been observed in all types of human cancer,indicating that mutations might contribute to tumorigenesis,metastasis,recurrence,or drug *** possibility is appealing because of the known shift from oxidative metabolism to glycolysis,known as the Warburg effect,that occurs in *** DNA(mtDNA)mutations could either bematernally inherited and predispose to cancer(germ line mutations)or occur sporadically in the mtDNA of specific tissues(rissue-or tumor-specific somatic mutations)and contribute to the tumor initiation and progression ***-throughput sequencing technologies now enable comprehensive detection of mtDNA variation in tissues and bodily fluids,with the potential to be used as an early detectiontool that may impact the treatment of ***,we discuss insights into the roles of mtDNA mutations in carcinogenesis,highlighting the complexities involved in the analysis and interpretation of mitochondrial genomic *** challenges in studying their contribution to pathogenesis,and the value of mtDNA mutations in developing early detection,diagnosis,prognosis,and therapeuticstrategics for cancer.

关键词： Mitochondrial DNA Cancer Genetic variation

2022—2023年度影视获奖作品的审美特征探析

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三明学院学报 2024年第2期41卷 38-44页

作者：毕耕阮邓春莺华中农业大学文法学院湖北武汉430070

2022—2023年度中国影视优秀作品的评奖已经结束,电影百花奖、金鸡奖、华表奖与电视飞天奖、星光奖、金鹰奖、白玉兰奖等各大奖项也已揭晓。这些获奖作品紧扣时代主题,书写人间正道,弘扬主旋律,表现真善美,充满正能量,注重内容与形式的... 详细信息

2022—2023年度中国影视优秀作品的评奖已经结束,电影百花奖、金鸡奖、华表奖与电视飞天奖、星光奖、金鹰奖、白玉兰奖等各大奖项也已揭晓。这些获奖作品紧扣时代主题,书写人间正道,弘扬主旋律,表现真善美,充满正能量,注重内容与形式的完美融合,追求思想性与艺术性的有机统一,具有现实主义的艺术风格与审美特征,因而受到了社会公众的广泛欢迎和好评。此外,这些优秀作品的获奖还具有重要的启示意义,有利于引领当代影视创作的新风尚、新潮流,促进民族影视艺术的繁荣与发展。

关键词：中国影视影视评奖审美特征