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Transient response of doubly-curved bio-inspired composite shells resting on viscoelastic foundation subject to blast load using improved first-order shear theory and isogeometric approach

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Defence Technology（防务技术） 2024年第8期38卷 171-193页

作者： Thuy Tran Thi Thu Tu nguyen anh Hue nguyen Thi Hong nguyen Thi School of Mechanical and Automotive Engineering Hanoi University of IndustryHanoiViet Nam Faculty of Technical Fundamental University of Transport TechnologyHanoiViet Nam Faculty of Mechanical Engineering Thuyloi University175 Tay SonDong DaHanoiViet Nam

Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.

关键词： Blast load Modified first-order shear theory Biological composite structures

Truly optimal semi-active damping to control free vibration of a single degree of freedom system

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 142-145页

作者： Viet Duc La Ngoc tuan nguyen Institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 10000Vietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

This paper studies a single degree of freedom system under free vibration and controlled by a general semiactive damping.A general integral of squared error is considered as the performance index.A one-time switching damping controller is proposed and *** pontryagin maximum principle is used to prove that no other form of semi-active damping can provide the better performance than the proposed one-time switching damping.

关键词： Analytical optimization Quadratic integral Lyapunov equation Pontryagin maximum principle

Characteristics of the gene encoding pyrroline-5-carboxylate synthase(P5CS) in Vietnamese soybean cultivars(Glycine max ***)

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Characteristics of the gene encoding pyrroline-5-carboxylate...

Optical Sum Frequency Generation Image of Rice Grains

International Conference on Biology, Environment and Chemistry（ICBEC 2010）

作者： Chu Hoang Mau nguyen Thi Thuy Huong Chu Hoang Lan nguyen tuan anh Le Van Son Chu Hoang Ha Dept.of Genetics Faculty of Biology Thainguyen University Dept.of Genetics Faculty of Biology Vietnam National University of Science Dept.of Environment Faculty of Agricultural Environment Thainguyen University Lab.of Plant Cell Biotechnology Institute of Biotechnology

ISBN: (纸本)9789810886424

This research evaluates the ability of six soybean local cultivars and a control cultivar(DT84) to tolerate severe *** this research,SL5 and SL6 have the most stress tolerance while DT84 and SL1 have the least stress *** have isolated P5CS gene as it relates to stress tolerance by using PCR with *** results show that the size of the P5CS gene of the studied cultivars is 2,148 bp,which encodes for 715 amino *** these proteins are compared with the P5CS proteins of the other species,the result shows that the isolated P5CS proteins have a higher identity than other bean *** are located on the same branch of the phylogenetic ***(Pro) is one of the most accumulated osmolytes in salinity and water deficit conditions in plants.P5CS is a key regulatory enzyme involved in prolin biosynthesis in plants and is subject to feedback inhibition by *** conserved aspartate residue at 126 and the phenylalanine at 129 are involved in the feedback inhibition by Pro binding.A gene encoding a feedback insensitive P5CS enzyme was obtained by mutating the P5CS *** mutation was due to a change of an aspartate at position 125 to alanine in the *** mutated gene was cloned in pBT vector and *** gene will be transfered to plants to increase the level of proline overproduction and to enhance the drought tolerance ability.

关键词： drought,Glycine max,point mutation,P5CS,proline.

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Journal of Biomaterials and Nanobiotechnology 2012年第2期3卷 286-291页

作者： Hongyan Li Yoshihiro Miyauchi nguyen anh tuan Goro Mizutani Mikio Koyano Japan Advanced Institute of Science and Technology 1-1 Asahidai Nomi Ishikawa 923-1292 Japan

We observed optical sum frequency generation (SFG) images of cross-sections of glutinous rice grains, in order to test a possibility of the SFG microscopy as a tool for monitoring polysaccharide species in rice grains. The SFG response in the CH vibration range was the most intense in the crush cell layer at the edge of the endosperm adjacent to the embryo probably due to optical reflection and scattering effectby the rugged dielectric structure of the crush cell layer. The SFG spectra as a function of the infrared wavelength depended on the measurement position in the endosperm. The SFG results were compared with those by Raman and infrared spectroscopies for the same samples.

关键词： Optical Sum Frequency Generation Microscopy Oryzaglutinosa (Rice) Amylopectin Starch Crush Cell Layer Endosperm

EP Aquarii:A New Picture of the Circumstellar Envelope

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Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham T.Nhung Do T.Hoai Pierre Darriulat Pham tuan-anh Pham N.Diep nguyen B.Ngoc Tran T.Thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars

越南北部Cao Bang省与W-Sn矿化有关的Piaoac花岗岩岩石学

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越南北部Cao Bang省与W-Sn矿化有关的Piaoac花岗岩岩石学

作者：阮俊英（nguyen tuan anh）中国科学技术大学

学位级别：硕士

白垩纪岩浆岩在越南北部和中国华南(NV-SCB)广泛分布,与锡多金属矿化有着紧密的联系。研究这些岩浆岩的成因不仅对认识越南北部-华南(NV-SCB)的演化有重要意义,而且有利于锡多金属矿床的勘探。目前,对这些与矿化有关的岩浆岩仍缺乏约束... 详细信息

白垩纪岩浆岩在越南北部和中国华南(NV-SCB)广泛分布,与锡多金属矿化有着紧密的联系。研究这些岩浆岩的成因不仅对认识越南北部-华南(NV-SCB)的演化有重要意义,而且有利于锡多金属矿床的勘探。目前,对这些与矿化有关的岩浆岩仍缺乏约束其成因和形成构造环境的深入研究。已出版的越南北部-华南(NV-SCB)与矿化有关岩浆岩的相关数据和构造模型,可以提供越南北部(NV)和华南(SCB)在晚白垩世相对明晰的演化机制和过程。在本研究中,我们展示了越南北部Cao Bang省Piaoac花岗岩体新的地质学、地球化学、矿物化学和Hf同位素数据,并将其与中国南部的都龙锡多金属矿区对比。本研究阐明了Cao Bang地区与钨锡矿化有关的岩浆岩的成因。此外,我们进一步约束了越南北部-华南(NV-SCB)晚白垩世岩石的成因和构造背景。Piaoac岩体包括中到细粒的二云母花岗岩,具斑状结构(含长石斑晶)。这些花岗岩以高硅(Si02:72.37-73.07 wt.%)、强过铝质(ASI=1.61-1.65)、富集Rb、U、Ta和P、亏损Ba、Nb、La、Eu和Ti为特征。侵入体中锆石高的Th/U比(>0.1)和清晰的振荡环带指示了锆石为岩浆起源。Piaoac岩体的结晶年龄约82Ma,指示晚白垩世。岩体低的CaO/Na2O比(<0.3)和高的SiO2含量暗示了花岗岩熔体通过变泥质岩的部分熔融形成。花岗岩的锆石负的εHf(t)(-9.69 to-0.9)和二阶段模式年龄(TDM2)暗示了母岩浆源于新元古代变沉积岩(1.2 Ga to 1.7 Ga),这与华南的基底岩石一致。两个主要因素影响了这些花岗岩中的钨锡矿化:首先,斜长石、黑云母和长石的高度的分离结晶使W、Sn在花岗质熔体积累;其次,低氧逸度(低于MH缓冲剂)环境能有效地将W、Sn迁移至热液流体,并且导致W-Sn矿物的沉淀。结合文献中与中国西南部与W-Sn矿化有关花岗岩的资料,即它们形成于岩石圈减薄和软流圈上涌的环境,而Piaoac岩体与这些花岗岩具有相似的特征和形成时代,故暗示了它们处于相同的构造环境。地球化学数据指示了Piaoac花岗岩形成于与晚白垩世岩浆活动有关的伸展构造背景,这与华南板块发生大规模的岩石圈伸展有关。

关键词： Piaoac花岗岩 W-Sn矿化越南北部

Unknown DDoS Attack Detection with Fuzzy C-Means Clustering and Spatial Location Constraint Prototype Loss

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Computers, Materials & Continua 2024年第2期78卷 2181-2205页

作者： Thanh-Lam nguyen HaoKao Thanh-tuan nguyen Mong-Fong Horng Chin-Shiuh Shieh Department of Electronic Engineering National Kaohsiung University of Science and TechnologyKaohsiung807618Taiwan Department of Electronic and Automation Engineering Nha Trang UniversityNha Trang650000Vietnam

Since its inception,the Internet has been rapidly *** the advancement of science and technology and the explosive growth of the population,the demand for the Internet has been on the *** applications in education,healthcare,entertainment,science,and more are being increasingly deployed based on the ***,malicious threats on the internet are on the rise as *** Denial of Service(DDoS)attacks are among the most common and dangerous threats on the internet *** scale and complexity of DDoS attacks are constantly *** Detection Systems(IDS)have been deployed and have demonstrated their effectiveness in defense against those *** addition,the research of Machine Learning(ML)and Deep Learning(DL)in IDS has gained effective results and significant ***,one of the challenges when applying ML and DL techniques in intrusion detection is the identification of unknown *** attacks,which are not encountered during the system’s training,can lead to misclassification with significant *** this research,we focused on addressing the issue of Unknown Attack Detection,combining two methods:Spatial Location Constraint Prototype Loss(SLCPL)and Fuzzy C-Means(FCM).With the proposed method,we achieved promising results compared to traditional *** proposed method demonstrates a very high accuracy of up to 99.8%with a low false positive rate for known attacks on the Intrusion Detection Evaluation Dataset(CICIDS2017)***,the accuracy is also very high,reaching 99.7%,and the precision goes up to 99.9%for unknown DDoS attacks on the DDoS Evaluation Dataset(CICDDoS2019)*** success of the proposed method is due to the combination of SLCPL,an advanced Open-Set Recognition(OSR)technique,and FCM,a traditional yet highly applicable clustering *** has yielded a novel method in the field of unknown attack *** further expands the trend of applying DL and M

关键词： Cybersecurity DDoS unknown attack detection machine learning deep learning incremental learning convolutional neural networks(CNN) open-set recognition(OSR) spatial location constraint prototype loss fuzzy c-means CICIDS2017 CICDDoS2019

Generating highly active oxide-phosphide heterostructure through interfacial engineering to break the energy scaling relation toward urea-assisted natural seawater electrolysis

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Journal of Energy Chemistry 2024年第10期97卷 687-699页

作者： Ngoc Quang Tran Nam Hoang Vu Jianmin Yu Khanh Vy Pham nguyen Thuy Tien nguyen Tran Thuy-Kieu Truong Lishan Peng Thi anh Le Yoshiyuki Kawazoe Center for Innovative Materials and Architectures Vietnam National University Faculty of Materials Science and Technology University of Science Key Laboratory of Rare Earths Ganjiang Innovation Academy Chinese Academy of Sciences Department of Mechanical Engineering Hanbat National University (HBNU) School of Chemical Engineering-Hanoi University of Science and Technology New Industry Creation Hatchery Center Tohoku University

Urea-assisted natural seawater electrolysis is an emerging technology that is effective for grid-scale carbon-neutral hydrogen mass production yet *** scaling relations is an effective strategy to break through the bottleneck of natural seawater ***,by DFT calculation,we demonstrated that the interface boundaries between Ni2P and MoO2play an essential role in the selfrelaxation of the Ni-O interfacial bond,effectively modulating a coordination number of intermediates to control independently their adsorption-free energy,thus circumventing the adsorption-energy scaling *** this conceptual model,a well-defined 3D F-doped Ni2P-MoO2heterostructure microrod array was rationally designed via an interfacial engineering strategy toward urea-assisted natural seawater *** a result,the F-Ni2P-MoO2exhibits eminently active and durable bifunctional catalysts for both HER and OER in acid,alkaline,and alkaline sea water-based *** in-situ analysis,we found that a thin amorphous layer of NiOOH,which is evolved from the Ni2P during anodic reaction,is real catalytic active sites for the OER and UOR ***,such electrode-assembled urea-assisted natural seawater electrolyzer requires low voltages of 1.29 and 1.75 V to drive 10 and600 mA cm-2and demonstrates superior durability by operating continuously for 100 h at 100 mA cm-2,beyond commercial Pt/C || RuO2and most previous reports.

关键词： Break scaling relationships Doping Interfacial engineering Natural seawater splitting Urea electrolysis

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刘凤斌教授治疗溃疡性结肠炎经验

新中医 2014年第6期46卷 24-26页

作者： nguyen Thi Minh Thu nguyen tuan anh 刘凤斌广州中医药大学广州中医药大学第一附属医院广东广州510405

介绍刘凤斌教授治疗溃疡性结肠炎的经验,认为溃疡性结肠炎病位主要在脾与大肠,且与肝肾关系密切。病因病机可归纳为:热(湿热)、虚(脾虚、肾虚、脾肾虚)、气(气郁)、瘀(血瘀),临床上分急性期、缓解期,有热毒炽盛、大肠湿热、脾胃虚弱、... 详细信息

介绍刘凤斌教授治疗溃疡性结肠炎的经验,认为溃疡性结肠炎病位主要在脾与大肠,且与肝肾关系密切。病因病机可归纳为:热(湿热)、虚(脾虚、肾虚、脾肾虚)、气(气郁)、瘀(血瘀),临床上分急性期、缓解期,有热毒炽盛、大肠湿热、脾胃虚弱、脾肾不足、肝脾不调等证型。急性期治以清热祛湿为主,缓解期治以健脾渗湿为法,各阶段治疗均考虑到以脾胃为中心,五脏相关,配合疏肝、益肾之法;且气滞血瘀贯穿病程始终,可适当运用活血化瘀之法。临床辨证论治,诸法参用,且需慎饮食,调情志。

关键词：溃疡性结肠炎中医疗法刘凤斌