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Comparative Study of Genetic Structure and Genetic Diversity betweenWild and Cultivated Populations of Taxus cuspidata,Northeast China
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作者 Dandan Wang Xiaohong Li Yanwen Zhang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期355-369,共15页
Taxus cuspidata is a rare plant with important medicinal and ornamental value.Aiming at the obvious differences between wild and cultivated populations of T.cuspidata from Northeast China,a total of 61 samples,that is... Taxus cuspidata is a rare plant with important medicinal and ornamental value.Aiming at the obvious differences between wild and cultivated populations of T.cuspidata from Northeast China,a total of 61 samples,that is,33 wild yews and 28 cultivated yews were used to analyze the differences and correlations of the kinship,genetic diversity,and genetic structure between them by specific length amplified fragment sequencing(SLAF-seq).Finally,470725 polymorphic SLAF tags and 58622 valid SNP markers were obtained.Phylogenetic analysis showed that 61 samples were classified into 2 clusters:wild populations and cultivated populations,and some wild yews were categorized into the cultivated populations;the genetic diversity analysis showed that the Nei diversity index of wild populations(0.4068)was smaller than that of cultivated populations(0.4414),and the polymorphic information content(PIC)of wild populations(0.2861)was smaller than that of cultivated populations(0.3309).The genetic differentiation analysis showed that the total populations of gene diversity(H_(t))of cultivated and wild populations were respectively 0.8159 and 0.5685,the coefficient of gene differentiation(G_(st))of cultivated and wild populations was respectively 0.3021 and 0.1068,and the gene flow(N_(m))(2.4967)of wild populations was larger than cultivated populations(0.8199).The molecular variance(AMOVA)revealed that inter-population variation accounted for 29.57%of the total genetic variation,while intra-population variation accounted for 70.42% of the total genetic variation(p<0.001),this suggested that the genetic variation in the T.cuspidata is mainly attributed to within-population factors.In conclusion,the genetic distance between geographical ecological groups of wild populations was generally smaller than that of cultivated populations,and the degree of genetic diversity and genetic differentiation was smaller than that of cultivated populations.As evident,the utilization of SLAF-seq technology enables efficient and accurate development of SNP markers suitable for genetic analysis of T.cuspidata species.These developed SNP markers can provide a molecular foundation for T.cuspidata breeding,construction of genetic maps,variety identification,and association analysis of agronomic traits. 展开更多
关键词 t.cuspidata SLAF-seq SNP wild population cultivated population genetic structure
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Systematic Review of Community Type 2 Diabetes Structured Health Education (CT2DSHE)
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作者 Gift Phiri 《Open Journal of Nursing》 2024年第8期377-400,共24页
Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming t... Aim: This paper aims to evaluate disparities of type 2 diabetes structured health education programmes that is utilised within the communities. Design: systematic review, (a type of secondary research design) aiming to summarize the results of prior primary research studies on available evidence Community type 2 diabetes structured education (CT2DSHE). Methods: Research question: Type 2 diabetic structured health education within a community how effective is it? Qualitative Systematic review, defined as a way to get reliable and objective picture of current available evidence on the specific topic—(CT2DSHE), (Denscombe, 2021) through reflexivity synthesis of available data as an example. This is valuable in time constraints such as project assignments that must be met within specific time and also to bring together available evidence together [1]. Results: This review has shown that CT2DSHE is effective with seven out of the eleven authors supporting, three authors against and one was neutral, further showed that knowledge and skills acquired can last longer with patient activation improved among T2DM patients ideal for sustaining their self-management of T2DM. Conclusion: This research provides suggestive answers to the research question: “Type 2 diabetic structured health education within a community how effective is it?”, This has demonstrated CT2DSHE effectiveness in knowledge acquisition and improving T2DM awareness among T2DM patients, whilst evidencing long effects beyond the study times of 3 - 9 months period in relation to patient activation. Also Identified diabetes education self-management on newly diagnosed (DESMOND) patient as CT2DSHE program for recommendation. Patient or Public Contribution: This work aspires to contribute to CT2DSHE in these areas;Influencing policy decision-making for community diabetes care within the UK and world at large., Contributing to already vast knowledge on diabetes self-management and reasons why?, Influencing educators on how CT2DSHEP are designed, delivered by putting the patient at the Centre and bringing different perspectives on CT2DSHEP in one place that is serving users time of having to consult several resources especially busy clinicians [2] [3]. 展开更多
关键词 Community Health EDUCAtION EFFECtIVENESS Impact structured and Planned type 2 Diabetes (t2DM)
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Study on jet formation behavior and optimization of trunconical hypercumulation shaped charge structure 被引量:1
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作者 Chao Ge Zhuojun Qu +2 位作者 Jin Wang Die Hu Yong Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第3期196-206,共11页
Combining the methods of theoretical,numerical and experimental,this research focuses on the jet formation behavior and optimization of trunconical hypercumulation shaped charge structure.With the three-stage division... Combining the methods of theoretical,numerical and experimental,this research focuses on the jet formation behavior and optimization of trunconical hypercumulation shaped charge structure.With the three-stage division,formation theory of trunconical hypercumulation shaped charge jet is established based on micro element method.By dimensional analysis,main control parameters are identified and their effect on jet formation are analyzed.Through numerical modelling and orthogonal optimization method,influence of the factors and their levels over the indicators of jet tip velocity and jet length as well as order of the significance of each factor and level are obtained.Penetration experiments of trunconical hypercumulation shaped charge based on the orthogonal optimization reveals its advantage over traditional conical shaped charge structure,and finally determines the optimal influence factor level combination.The research and results would provide useful guide for the design and application of trunconical hypercumulation shaped charge structure. 展开更多
关键词 structure shapeD CHARGE
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INTEGRATION SHAPE AND SIZING OPTIMIZATION OF COMPOSITE WING STRUCTURE BASED ON RESPONSE SURFACE METHOD 被引量:7
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作者 王伟 杨伟 常楠 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第2期94-100,共7页
An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitabl... An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method (QRSM). The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting. 展开更多
关键词 composite structures shape optimization WINGS sizing optimization response surface method
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Analysis on the Composition and Structure of Branches of Two Kinds of Tree Shapes in Korla Fragrant Pear 被引量:2
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作者 成小龙 廖康 +4 位作者 李楠 赵世荣 孙慧瑛 曼苏尔.那斯尔 刘娟 《Agricultural Science & Technology》 CAS 2013年第7期954-958,共5页
ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distr... ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that: The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different. 展开更多
关键词 Korla fragrant pear tree shape Composition and structure of branch
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A Deep Learning Approach to Shape Optimization Problems for Flexoelectric Materials Using the Isogeometric Finite Element Method
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作者 Yu Cheng Yajun Huang +3 位作者 Shuai Li Zhongbin Zhou Xiaohui Yuan Yanming Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1935-1960,共26页
A new approach for flexoelectricmaterial shape optimization is proposed in this study.In this work,a proxymodel based on artificial neural network(ANN)is used to solve the parameter optimization and shape optimization... A new approach for flexoelectricmaterial shape optimization is proposed in this study.In this work,a proxymodel based on artificial neural network(ANN)is used to solve the parameter optimization and shape optimization problems.To improve the fitting ability of the neural network,we use the idea of pre-training to determine the structure of the neural network and combine different optimizers for training.The isogeometric analysis-finite element method(IGA-FEM)is used to discretize the flexural theoretical formulas and obtain samples,which helps ANN to build a proxy model from the model shape to the target value.The effectiveness of the proposed method is verified through two numerical examples of parameter optimization and one numerical example of shape optimization. 展开更多
关键词 shape optimization deep learning flexoelectric structure finite element method isogeometric
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Meso-mechanical analyses of shape memory alloy wires reinforced smart structures with damages
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作者 胡自力 周晚林 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期97-101,共5页
The thermo-mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structures with damages are analyzed through variational principle and meso-mechanical method.A governing equation on the structure is... The thermo-mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structures with damages are analyzed through variational principle and meso-mechanical method.A governing equation on the structure is derived.Mathematical expressions on meso-displacement field,stress-strain field of typical element with damages are presented.A failure criterion for interface failure between SMA wires and matrix is established under two kinds of actuation which are dead-load and temperature,where the temperature is included in effective free restoring strain.In addition,there are some other composing factors in the failure criterion such as interface properties,thermodynamical properties of SMA,initial debonding length L-l,etc.The results are significant to understand structural strength self-adaptive control and failure mechanism of SMA wires reinforced smart structures with damages,and provide a theoretical foundation for further study on the integrity of SMA smart structures. 展开更多
关键词 smart structure damage shape memory alloy FAILURE meso-mechanical analysis variational principle
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Effect of the L-D_(1)alleles on leaf morphology,canopy structure and photosynthetic productivity in upland cotton(Gossypium hirsutum L.)
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作者 JIANG Hui GAO Ming-wei +7 位作者 CHEN Ying ZHANG Chao WANG Jia-bao CHAI Qi-chao WANG Yong-cui ZHENG Jin-xiu WANG Xiu-li ZHAO Jun-sheng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第1期108-119,共12页
One of the most important objectives for breeders is to develop high-yield cultivars.The increase in crop yield has met with bottlenecks after the first green revolution,and more recent efforts have been focusing on a... One of the most important objectives for breeders is to develop high-yield cultivars.The increase in crop yield has met with bottlenecks after the first green revolution,and more recent efforts have been focusing on achieving high photosynthetic efficiency traits in order to enhance the yield.Leaf shape is a significant agronomic trait of upland cotton that affects plant and canopy architecture,yield,and other production attributes.The major leaf shape types,including normal,sub-okra,okra,and super-okra,with varying levels of lobe severity,are controlled by a multiple allelic series of the D-genome locus L-D_(1).To analyze the effects of L-D_(1)alleles on leaf morphology,photosynthetic related traits and yield of cotton,two sets of near isogenic lines(NILs)with different alleles were constructed in Lumianyan 22(LMY22)and Lumianyan 28(LMY28)backgrounds.The analysis of morphological parameters and the results of virus-induced gene silencing(VIGS)showed that the regulation of leaf shape by L-D_(1)alleles was similar to a gene-dosage effect.Compared with the normal leaf,deeper lobes of the sub-okra leaf improved plant canopy structure by decreasing the leaf area index(LAI)and increasing the light transmittance rate(LTR),and the mid-range LAI of sub-okra leaf also guaranteed the accumulation of cotton biomass.Although the chlorophyll content(SPAD)of sub-okra leaf was lower than those of the other two leaf shapes,the net photosynthetic rate(Pn)of sub-okra leaf was higher than those of okra leaf and normal leaf at most stages.Thus,the improvements in canopy structure,as well as photosynthetic and physiological characteristics,contributed to optimizing the light environment,thereby increasing the total biomass and yield in the lines with a sub-okra leaf shape.Our results suggest that the sub-okra leaf may have practical application in cultivating varieties,and could enhance sustainable and profitable cotton production. 展开更多
关键词 PHOtOSYNtHESIS canopy structure YIELD BIOMASS sub-okra leaf shape
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A Footpad Structure with Reusable Energy Absorption Capability for Deep Space Exploration Lander:Design and Analysis
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作者 Weiyuan Dou Xiaohang Qiu +2 位作者 Zhiwei Xiong Yanzhao Guo Lele Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第4期257-270,共14页
The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characte... The footpad structure of a deep space exploration lander is a critical system that makes the initial contact with the ground,and thereby plays a crucial role in determining the stability and energy absorption characteristics during the impact process.The conventional footpad is typically designed with an aluminum honeycomb structure that dissipates energy through plastic deformation.Nevertheless,its effectiveness in providing cushioning and energy absorption becomes significantly compromised when the structure is crushed,rendering it unusable for reusable landers in the future.This study presents a methodology for designing and evaluating structural energy absorption systems incorporating recoverable strain constraints of shape memory alloys(SMA).The topological configuration of the energy absorbing structure is derived using an equivalent static load method(ESL),and three lightweight footpad designs featuring honeycomb-like Ni-Ti shape memory alloys structures and having variable stiffness skins are proposed.To verify the accuracy of the numerical modelling,a honeycomb-like structure subjected to compression load is modeled and then compared with experimental results.Moreover,the influence of the configurations and thickness distribution of the proposed structures on their energy absorption performance is comprehensively evaluated using finite element simulations.The results demonstrate that the proposed design approach effectively regulates the strain threshold to maintain the SMA within the constraint of maximum recoverable strain,resulting in a structural energy absorption capacity of 362 J/kg with a crushing force efficiency greater than 63%. 展开更多
关键词 Deep space exploration lander Footpad shape memory alloy(SMA) Reusable energy absorption structure Design method
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An Electron Model Based on the Fine Structure Constant
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作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第5期553-561,共9页
In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed ... In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed to resolve the electron’s charge and mass inconsistencies. That model is modified in this document by assuming the electron’s radius is exactly equal to the classical electron radius. The attributes of the internal components of the electron’s structure have been recalculated accordingly. The shape of the electron is also predicted, and found to be slightly aspherical on the order of an oblate ellipsoid. This shape is attributed to centrifugal force and compliant outer shell material. It is interesting to note that all of the electron’s attributes, both external and internal, with the exception of mass and angular moment, are functions of the fine structure constant a, and can be calculated from just three additional constants: electron mass, Planck’s constant, and speed of light. In particular, the ratios of the outer shell charge and mass to the electron charge and mass, respectively, are 3/2a. The ratios of the central core charge and mass to the electron charge and mass, respectively, are 1-(3/2a). Attributes of the electron are compared with those of the muon. Charge and spin angular momentum are the same, while mass, magnetic moment, and radius appear to be related by the fine structure constant. The mass of the electron outer shell is nearly equal to the mass of the muon. The muon internal structure can be modeled exactly the same as for the electron, with exactly the same attribute relationships. 展开更多
关键词 Fine structure Constant Negative Mass Electron shape Electron structure Electron Mass Inconsistency Electron Charge Inconsistency MUON
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Probing microstructure of solid-state synthesized LiCoO_(2)with MAS NMR spectroscopy
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作者 Suyu Gu Guozhong Lu +4 位作者 Nianrui Guo Juncheng Xu Yu Jiang Ming Shen Bingwen Hu 《Magnetic Resonance Letters》 2023年第4期298-305,共8页
LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focus... LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focused on the realization of higher charging voltages to fully utilize its high theoretical capacity.However,an unambiguous atomic-level local probe is essential for the understanding of structure-function correlation.Here we employ highresolution solid-state nuclear magnetic resonance(NMR)spectroscopy to study the local atomic environments in LiCoO_(2)synthesized with three common sintering methods.While one-dimensional 7Li NMR shows distinct linewidth and subtle dependence on lithium over-stoichiometry,both 7Li and 59Co relaxation times are highly dependent on the sintering method.We prove that the two-step sintering method favors the elimination of unreacted Co3O4,thereby enabling the best discharge capacity in all-solid-state lithium batteries assembled with LiCoO_(2)/LGPS/LiIn,which is in accordance with its narrowest 7Li linewidth and the longest 7Li/59Co T1. 展开更多
关键词 LiCoO_(2) Solid-state NMR t1 relaxation Local structure
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A new isolation device using shape memory alloy and its application for long-span structures 被引量:3
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作者 Ding Youliang Chen Xin +1 位作者 Li Aiqun Zuo Xiaobao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2011年第2期239-252,共14页
The key points to consider in determining the effectiveness of using structural isolation with shape memory alloys (SMA) are the constitutive model, the SMA isolation device and the analysis method. In this paper, a... The key points to consider in determining the effectiveness of using structural isolation with shape memory alloys (SMA) are the constitutive model, the SMA isolation device and the analysis method. In this paper, a simplified constitutive model based on the classic theory of plasticity is proposed to simulate the behavior of the superelasticity of the SMA, in which the martensite volume fraction is considered as one of the state variables. Comparisons between simulation results and experimental results are made and indicate that the proposed constitutive model yields stress-strain curves that are in good agreement with the experimental ones. Thus, the proposed model can correctly simulate the yield mechanism and energy dissipation capacity of the SMA. Next, in order to make full use of the superelasticity of SMA, a new SMA isolator composed of pre-tensioned SMA bars is presented. Then, a finite element analytical model is established to simulate the behavior of the SMA isolator according to its configuration and simplified constitutive model. Finally, a simplified design method for long-span structures installed with SMA isolators is proposed, which is further used to investigate the isolation effects of a space grid structure. Results show that the SMA isolator can reduce the seismic responses of the structure effectively, which indicates the effectiveness of the proposed SMA isolation method. 展开更多
关键词 shape memory alloy super-elasticity constitutive model seismic response structural isolation space gridstructure
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Mechanical Behavior and Shape Optimization of Lining Structure for Subsea Tunnel Excavated in Weathered Slot 被引量:2
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作者 李鹏飞 周晓军 《China Ocean Engineering》 SCIE EI CSCD 2015年第6期875-890,共16页
Subsea tunnel lining structures should be designed to sustain the loads transmitted from surrounding ground and groundwater during excavation. Extremely high pore-water pressure reduces the effective strength of the c... Subsea tunnel lining structures should be designed to sustain the loads transmitted from surrounding ground and groundwater during excavation. Extremely high pore-water pressure reduces the effective strength of the country rock that surrounds a tunnel, thereby lowering the arching effect and stratum stability of the structure. In this paper, the mechanical behavior and shape optimization of the lining structure for the Xiang'an tunnel excavated in weathered slots are examined. Eight cross sections with different geometric parameters are adopted to study the mechanical behavior and shape optimization of the lining structure. The hyperstatic reaction method is used through finite element analysis software ANSYS. The mechanical behavior of the lining structure is evidently affected by the geometric parameters of crosssectional shape. The minimum safety factor of the lining structure elements is set to be the objective function. The efficient tunnel shape to maximize the minimum safety factor is identified. The minimum safety factor increases significantly after optimization. The optimized cross section significantly improves the mechanical characteristics of the lining structure and effectively reduces its deformation. Force analyses of optimization process and program are conducted parametrically so that the method can be applied to the optimization design of other similar structures. The results obtained from this study enhance our understanding of the mechanical behavior of the lining structure for subsea tunnels. These results are also beneficial to the optimal design of lining structures in general. 展开更多
关键词 subsea tunnel lining structure shape optimization safety factor hyperstatic reaction method
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Optimum Design of Structure Shape for Offshore Jacket Platforms 被引量:2
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作者 封盛 宋玉普 张日向 《China Ocean Engineering》 SCIE EI 2000年第4期435-445,共11页
With the introduction of the design variables of nodal coordinates, which reflect the embedded depth of the pile and the jacket bed height, a shape optimum design model for offshore jacket platforms is established. A ... With the introduction of the design variables of nodal coordinates, which reflect the embedded depth of the pile and the jacket bed height, a shape optimum design model for offshore jacket platforms is established. A sequential two-level optimum algorithm is developed based on the design variable gradation. On the basis of the finite element method, the sensitivity of the objective function and nodal displacement is analyzed. As an example, the BZ281 oil storage offshore platform, which ties in the Bohai oil field, is designed with the shape optimum model. The results are compared with the cross-section optimum design. The tendency of design variables and its reasons in the two methods are analyzed. In the shape optimum design, the value of objective function is obviously smaller than that of the initial design and the cross-section optimum design. Therefore, the advantage of structure shape optimum design for jacket platforms is remarkable. 展开更多
关键词 offshore jacket platform structure shape optimization sensitivity analysis
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Extraction of mode shapes of beam-like structures from the dynamic response of a moving mass 被引量:2
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作者 Yao Zhang Longqi Wang +1 位作者 Haisheng Zhao Seng Tjhen Lie 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第3期664-673,共10页
This paper proposes an approach to extract the mode shapes of beam-like structures from the dynamic response of a moving mass. When a mass passes through a beam containing several artificially installed humps, its ver... This paper proposes an approach to extract the mode shapes of beam-like structures from the dynamic response of a moving mass. When a mass passes through a beam containing several artificially installed humps, its vertical acceleration can be recorded. After applying fast Fourier transformation to the dynamic response, one can extract the mode shapes of the beam. The surface roughness was neglected compared to the humps and its adverse effect on the extraction was reduced. The passing mass performs as both “exciter” and “massage receiver”;therefore, this method requires only one single accelerometer, making it more convenient and time saving in practice. Moreover, to estimate the possible error in extracting mode shapes, a wavenumber domain filtering technique is used to reconstruct the general profiles of mode shapes. Experimental validation of this approach in laboratory scale was conducted. The experimental results show that the proposed method performs well in extracting lower order mode shapes. It should also be noted that the passing mass can not have a very high velocity (e.g. 80 mm/s), otherwise the mass may jump and separate from the beam, and the proposed method may fail to identify mode shapes. 展开更多
关键词 Mode shape Beam-like structureS MOVING mass Artificially installed humps Fast FOURIER tRANSFORMAtION
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Study on liquid-filled structure target with shaped charge vertical penetration 被引量:1
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作者 Min Guo Xu-dong Zu +1 位作者 Xiao-jun Shen Zheng-xiang Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第6期861-867,共7页
Based on the characteristic expanded hole of a shaped charge jet(SCJ) for target penetration and the reflow characteristics of liquids,the liquid-filled structure of a target disturbs the stability of the SCJ acquired... Based on the characteristic expanded hole of a shaped charge jet(SCJ) for target penetration and the reflow characteristics of liquids,the liquid-filled structure of a target disturbs the stability of the SCJ acquired in two independent parts.The interference jet speed interval,the escape jet speed interval,and the surplus depth are calculated on the basis of the virtual origin theory.The experimental results,including the velocity of the escaped jet tip and the surplus depth of penetration,are consistent with the theoretical results.Experiments show that the theory can describe the interaction process of the target with a shaped charge jet. 展开更多
关键词 shaped charge Liquid-filled structure target Disturbed jet Escape jet
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Influence of a liquid-filled compartment structure on the incoming shaped charge jet stability 被引量:2
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作者 X.D.Zu Z.X.Huang +2 位作者 Z.W.Guan X.C.Yin Y.M.Zheng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第2期571-582,共12页
Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compartment ... Liquid-filled compartment structure consists of a bulk steel plate with matrix blind holes which are filled with liquid and a steel front plate to seal up the liquid with rings and bolts.The liquid-filled compartment structure can resist the shaped charge warhead effectively.This paper presents experimental and theoretical investigations of the penetration ability of the residual shaped charge jet emerging from the liquid-filled compartment structure after the penetration process at different impact angles.On the basis of shock wave propagation theory,the influence of the liquid-filled compartment structure on jet stability is analysed.The interferences of the liquid backflow caused by a reflected shock wave and a back plate on jet stability under different impact angles are also examined.In addition,the range of the disturbed velocity segments of the jet at different impact angles and the penetration ability of the residual jet are obtained.A theoretical model is validated against the experimental penetration depths. 展开更多
关键词 Compartment structure shaped charge jet Shock wave DIStURBANCE StABILItY
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MESO-MECHANICAL ANALYSIS OF SHAPE MEMORY ALLOY REINFORCED SMART STRUCTURE WITH DAMAGE 被引量:1
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作者 Hu Zili 《Acta Mechanica Solida Sinica》 SCIE EI 2006年第3期189-195,共7页
The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical exp... The mechanical behaviors of shape memory alloy (SMA) wires reinforced smart structure with damage were analyzed through the variational principle, a governing equation for the structure was derived, mathematical expressions for the meso-displacement field, stressstrain field of typical element with damage were presented, and a failure criterion for interface failure between SMA wires and matrix was established under two kinds of actuation which are dead-load and temperature, where the temperature is included in effective free restoring strain. In addition, there are some other composing factors in the failure criterion such as the interface properties, dynamical properties of SMA, initial debonding length L - l etc. The results are significant to understand structural strength self-adapted control and failure mechanism of SMA wires reinforced smart structure with damage. 展开更多
关键词 smart structures DAMAGE shape memory alloy FAILURE meso-mechanical analysis variational principle
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Compressive mechanical properties and shape memory effect of NiTi gradient lattice structures fabricated by laser powder bed fusion 被引量:3
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作者 Wei Chen Dongdong Gu +3 位作者 Jiankai Yang Qin Yang Jie Chen Xianfeng Shen 《International Journal of Extreme Manufacturing》 SCIE EI CAS 2022年第4期189-205,共17页
Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanica... Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanical equipment application fields. In this study, we designed four gradient lattice structures (GLSs) using the topology optimization method, including the unidirectional GLS, the bi-directional increasing GLS, the bi-directional decreasing GLS and the none-GLS. All GLSs were manufactureed by laser powder bed fusion (LPBF). The uniaxial compression tests and finite element analysis were conducted to investigate the influence of gradient distribution features on deformation modes and energy absorption performance of GLSs. The results showed that, compared with the 45° shear fracture characteristic of the none-GLS, the unidirectional GLS, the bi-directional increasing GLS and the bi-directional decreasing GLS had the characteristics of the layer-by-layer fracture, showing considerably improved energy absorption capacity. The bi-directional increasing GLS showed a unique combination of shear fracture and layer-by-layer fracture, having the optimal energy absorption performance with energy absorption and specific energy absorption of 235.6 J and 9.5 J g-1 at 0.5 strain, respectively. Combined with the shape memory effect of NiTi alloy, multiple compression-heat recovery experiments were carried out to verify the shape memory function of LPBF-processed NiTi GLSs. These findings have potential value for the future design of GLSs and the realization of shape memory function of NiTi components through laser AM. 展开更多
关键词 additive manufacturing laser powder bed fusion gradient lattice structures deformation behavior shape memory effect
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Influence of shaped charge structure parameters on the formation of linear explosively formed projectiles 被引量:1
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作者 Tian-bao Ma Jing Liu Qi Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第10期1863-1874,共12页
The research of LEFP(linear explosive forming projectile)is of great value to the development of new warhead due to its excellent performance.To further improve the damage ability of the shaped charge warhead,a specia... The research of LEFP(linear explosive forming projectile)is of great value to the development of new warhead due to its excellent performance.To further improve the damage ability of the shaped charge warhead,a special shell overhanging structure was designed to increase the charge based on the traditional spherical charge,in which case the crushing energy of LEFP could be guaranteed.LS-DYNA was used to simulate different charge structures obtained by changing the number of detonation points,the length of shell platform,the radius of curvature and the thickness of liner.The RSM(response surface model)between the molding parameters of LEFP and the structural parameters of charge was established.Based on RSM model,the structure of shaped charge was optimized by using multi-objective genetic algorithm.Meanwhile,the formation process of jet was analyzed by pulsed X-ray photography.The results show that the velocity,length-diameter ratio and specific kinetic energy of the LEFP were closely related to the structural parameters of the shaped charge.After the optimization of charge structure,the forming effect and penetration ability of LEPP had been significantly improved.The experimental data of jet velocity and length were consistent with the numerical results,which verifies the reliability of the numerical results. 展开更多
关键词 LEFP Numerical simulation shaped charge structure optimization
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