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optimum Anti-erosion Structures and Anti-erosion Mechanism for Rotatory Samples Inspired by Scorpion Armor of Parabuthus transvaalicus

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Journal of Bionic Engineering 2021年第1期18卷 92-102页

作者： Shuaijun Zhang Wenna Chen Bo Li Shichao Niu Haiyue Yu Yahua Liu Xiao Yang Junqiu Zhang Zhiwu Han Luquan Ren Key Laboratory of Bionic Engineering(Ministry of Education China)Jilin UniversityChangchun 130022China Key L.aboratory for Precision and Non-traditional Machining Tiechnology of Ministry of Eiducation Dalian Uiniversity of TechnologyDalian 116024China School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China

Solid particle erosion on the material surfaces is a very common phenomenon in the industrial field,which greatly affects the efficiency,service life,and even poses a great threat to life safety.However,current research on erosion resistance is not only inefficient,but also limited to the improvement of hardness and toughness of materials.Inspired by typical scorpion(Parabuthus transvaalicus),biomimetic functional samples with exquisite anti-rosion structures were manufactured.Macroscopic morphology and structure of the biological prototype were analyzed and measured.According to above analysis,combined with response surface methodology,a set of biomimetic samples with different structural parameters were fabricated by using 3D printing technology.The anti-crosion performance of these biomimetic samples was investigated using a blasting jet machine.Based on the results of blasting jet test,as well as regression analysis and fiting,the optimal structural parameters were obtained.In addition to the static test conditions,the optimal biomimetic sample was also eroded in rotating condition and showed excellent erosion resistance property.The presence of bump and groove structures,on the one hand,reduced the croded area of biominetic sample surface.On the other hand,they made the airlow turbulent and consequently reduced the impact cnergy of solid particles,which significantly improved the erosion resistance of biomimetic materials.This study provides a new strategy to improvethe service life of components easily affected by erosion in the aviation,energy and military fields.

关键词： anti-erosion optimum mechanism for rotatory sample biomimetic fabrication scorpion

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optimum lateral extent of soil domain for dynamic SSI analysis of RC framed buildings on pile foundations

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Frontiers of Structural and Civil Engineering 2020年第1期14卷 62-81页

作者： Nishant SHARMA Kaustubh DASGUPTA Arindam DEY Department of Civil Engineering Indian Institute of Technology GuwahatiGuwahati 781039India

This article describes a novel approach for deciding optimal horizontal extent of soil domain to be used for finite element based numerical dynamic soil structure interaction(SSI)studies.SSI model for a 12 storied building frame,supported on pile foundation-soil system,is developed in the finite element based software framework,OpenSEES.Three different structure-foundation configurations are analyzed under different ground motion characteristics.Lateral extent of soil domain,along with the soil properties,were varied exhaustively for a particular structural configuration.Based on the reduction in the variation of acceleration response at different locations in the SSI system(quantified by normalized root mean square error,NRMSE),the optimum lateral extent of the soil domain is prescribed for various structural widths,soil types and peak ground acceleration levels of ground motion.Compared to the past studies,error estimation analysis shows that the relationships prescribed in the present study are credible and more inclusive of the various factors that influence SSI.These relationships can be readily applied for deciding upon the lateral extent of the soil domain for conducting precise SSI analysis with reduced computational time.

关键词： soil structure interaction optimum lateral extent of soil domain length multi-storyed framed building pile foundation OpenSEES L-K boundaries dynamic analysis

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optimum blade loading for a powered rotor in descent

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Chinese Journal of Aeronautics 2016年第3期29卷 580-584页

作者： Ramin Modarres David A.Peters Department of Mechanical Engineering & Materials Science Washington University in St.Louis

The optimum loading for rotors has previously been found for hover, climb and wind turbine conditions; but, up to now, no one has determined the optimum rotor loading in descent. This could be an important design consideration for rotary-wing parachutes and low-speed des- cents. In this paper, the optimal loading for a powered rotor in descent is found from momentum theory based on a variational principle. This loading is compared with the optimal loading for a rotor in hover or climb and with the Betz rotor loading （which is optimum for a lightly-loaded rotor）. Wake contraction for each of the various loadings is also presented.

关键词： Descent HelicopterInflow Loading optimum

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optimum Super-simple Mixed Covering Arrays of Type a^1b^k-1

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Acta Mathematica Sinica,English Series 2017年第1期33卷 153-164页

作者： Ce SHI School of Mathematics and Information Science Shanghai Lixin University of Commerce Shanghai 201620 Po R. China

A mixed covering array （MCA） of type （v1,v2,..., vk）, denoted by MCAλ（N; t, k, （v1,v2,...,Vk））, is an N × k array with entries in the i-th column from a set Vi of vi symbols and has the property that each N×t sub-array covers all the t-tuples at least A times, where 1≤i ≤ k. An MCAλ（N; t, k, （vl,v2,... ,vk）） is said to be super-simple, if each of its N x （t ＋ 1） sub-arrays con- tains each （t＋1）-tuple at most once. Recently, it was proved by Tang, Yin and the author that an optimum super-simple MCA of type （a, b, b,..., b） is equivalent to a mixed detecting array （DTA） of type （a, b, b,..., b） with optimum size. Such DTAs can be used to generate test suites to identify and determine the interaction faults between the factors in a component-based system. In this paper, some combinatorial constructions of optimum super-simple MCAs of type （a, b, b,..., b） are provided. By employing these constructions, some optimum super-simple MCAs are then obtained. In particu- lar, the spectrum across which optimum super-simple MCA2（2b2; 2, 4, （a, b, b, b））＇s exist, is completely determined, where 2 ≤ a ≤ b.

关键词： Mixed covering arrays super-simple optimum detecting arrays existence

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optimum Detecting Arrays for Independent Interaction Faults

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Acta Mathematica Sinica,English Series 2016年第2期32卷 199-212页

作者： Ce SHI Cheng Min WANG School of Mathematics and Information Science Shanghai Lixin University of Commerce School of Science Jiangnan University

The use of detecting arrays （DTAs） is motivated by the need to locate and detect interaction faults arising between the factors in a component-based system in software testing. The optimality and construction of DTAs have been investigated in depth for the case in which all the interaction faults are assumed to have the same strength; however, as a practical concern, the strengths of these faults are not always identical. For real world applications, it would be desirable for a DTA to be able to identify and detect faulty interactions of a strength equal to or less than a specified value under the assumption that the faulty interactions are independent from one another. To the best of our knowledge, the optimality and construction of DTAs for independent interaction faults have not been studied systematically before, In this paper, we establish a general lower bound on the size of DTAs for independent interaction faults and explore the combinatorial feature that enable these DTAs to meet the lower bound. Taking advantage of this combinatorial characterization, several classes of optimum DTAs meeting the lower bound are presented.

关键词： Detecting arrays super-simple independent interaction faults optimum

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Spatial patterns of vegetation and climate in the North China Plain during the Last Glacial Maximum and Holocene climatic optimum

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Science China Earth Sciences 2019年第8期62卷 1279-1287页

作者： Manyue LI Shengrui ZHANG Qinghai XU Jule XIAO Ruilin WEN Institute of Nihewan Archaeology Hebei Normal UniversityShijiazhuang050024China College of Resources and Environment Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang050024China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China CAS Center for Excellence in Life and Paleoenvironment Beijing100044China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China

Reconstructing the spatial patterns of regional climate and vegetation during specific intervals in the past is important for assessing the possible responses of the ecological environment under future global warming scenarios. In this study, we reconstructed the history of regional vegetation and climate based on six radiocarbon-dated pollen records from the North China Plain. Combining the results with existing pollen records, we reconstruct the paleoenvironment of the North China Plain during the Last Glacial Maximum(LGM) and the Holocene Climatic optimum(HCO). The results show that changes in the regional vegetation since the LGM were primarily determined by climatic conditions, the geomorphic landscape and by human activity.During the LGM, the climate was cold and dry;mixed broadleaf-coniferous forest and deciduous-evergreen broadleaf forest developed in the southern mountains, and cold-resistant coniferous forest and mixed broadleaf-coniferous forest were present in the northern mountains. The forest cover was relatively low, with mesophytic and hygrophilous meadow occupying the southern part of the plain, and temperate grassland and desert steppe were distributed in the north;Chenopodiaceae-dominated halophytes grew on the exposed continental shelf of the Bohai Sea and Yellow Sea. During the HCO, the climate was warm and wet;deciduous broadleaf forest and deciduous-evergreen broadleaf forest, with subtropical species, developed in the southern mountains, and deciduous broadleaf forest with thermophilic species was present in northern mountains. Although the degree of forest cover was greater than during the LGM, the vegetation of the plain area was still dominated by herbs, while halophytes had migrated inland due to sea level rise. In addition, the expansion of human activities, especially the intensification of cultivation,had a significant influence on the natural vegetation. Our results provide data and a scientific basis for paleoclimate modelling and regional carbon cycle assessment in north China, w

关键词： North China Plain Last Glacial Maximum Holocene Climatic optimum Pollen Vegetation Paleoenvironment

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Global optimum of microstructure parameters in the CMWP line-profile-analysis method by combining Marquardt-Levenberg and Monte-Carlo procedures

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Journal of Materials Science & Technology 2019年第7期35卷 1508-1514页

作者： Gabor Ribarik Bertalan Joni Tamas Ungar Department of Materials Physics Edtvos University BudapestPO Box 32H-15J8Hungary School of Materials The University of ManchesterM139PLUK

Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-Multiple-Whole-Profile (CMWP) procedure is based on physical profile functions for dislocations, domain size, stacking faults and twin boundaries. Order dependence, strain anisotropy, hkl dependent broadening of planar defects and peak shape are used to separate the effect of different lattice defect types. The Marquardt-Levenberg (ML) numerical optimiza-tion procedure has been used successfully to determine crystal defect types and densities. However, in more complex cases like hexagonal materials or multiple phases the ML procedure alone reveals uncer-tainties. In a new approach the ML and a Monte-Carlo statistical method are combined in an alternative manner. The new CMWP procedure eliminates uncertainties and provides globally optimized parameters.

关键词： X-ray line profile analysis Neutron line profile analysis CMWP Global optimum Dislocation densities Grain size Planar defects Monte-Carlo method

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Sequence homolog-based molecular engineering for shifting the enzymatic pH optimum

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Synthetic and Systems Biotechnology 2016年第3期1卷 195-206页

作者： Fuqiang Ma Yuan Xie Manjie Luo Shuhao Wang You Hu Yukun Liu Yan Feng Guang-Yu Yang State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240China School of Statistics East China Normal UniversityShanghai 200241China Shanghai Collaborative Innovation Center for Biomanufacturing(SCICB) East China University of Science and Technology130 Meilong RoadShanghai 200237China

Cell-free synthetic biology system organizes multiple enzymes(parts)from different sources to implement unnatural catalytic functions.Highly adaption between the catalytic parts is crucial for building up efficient artificial biosynthetic systems.Protein engineering is a powerful technology to tailor various enzymatic properties including catalytic efficiency,substrate specificity,temperature adaptation and even achieve new catalytic functions.However,altering enzymatic pH optimum still remains a challenging task.In this study,we proposed a novel sequence homolog-based protein engineering strategy for shifting the enzymatic pH optimum based on statistical analyses of sequence-function relationship data of enzyme family.By two statistical procedures,artificial neural networks(ANNs)and least absolute shrinkage and selection operator(Lasso),five amino acids in GH11 xylanase family were identified to be related to the evolution of enzymatic pH optimum.Site-directed mutagenesis of a thermophilic xylanase from Caldicellulosiruptor bescii revealed that four out of five mutations could alter the enzymatic pH optima toward acidic condition without compromising the catalytic activity and thermostability.Combination of the positive mutants resulted in the best mutant M31 that decreased its pH optimum for 1.5 units and showed increased catalytic activity at pH<5.0 compared to the wild-type enzyme.Structure analysis revealed that all the mutations are distant from the active center,which may be difficult to be identified by conventional rational design strategy.Interestingly,the four mutation sites are clustered at a certain region of the enzyme,suggesting a potential“hot zone”for regulating the pH optima of xylanases.This study provides an efficient method of modulating enzymatic pH optima based on statistical sequence analyses,which can facilitate the design and optimization of suitable catalytic parts for the construction of complicated cell-free synthetic biology systems.

关键词： enzymatic optimum shifting

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Zemax-Based optimum Structural Design of Probe of an Optical-Fiber Sensor

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第2期35卷 309-317页

作者： Hang Tianyuan Wang Xiaolei Liu Feng Ye Song Chen Zhentao Meteorological Oceanographic College National University of Defense Technology

Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(OFP)made of sapphire to overcome the limitations of existing materials(e.g.,high brittleness,poor corrosion resistance,and narrow bandwidth)and thereby enhance the detection performance of the OFP by improving its structure.Based on total internal reflection and light refraction,a simulation model of the probe is established in the Zemax optical design software to optimize the probe tip and matching mode of the two probe tips.The results show that the optimum OFP tip is a conical sapphire one with a cone angle of 35°.Tests are then conducted on a bespoke OFP sensor,the results of which are consistent with those predicted theoretically.The simulation results lay the foundation for the integrated design of OFP sensors and the optimization of their internal optics.The findings could also be applied to OFPs with multiple tips.

关键词： bubble measurement optical-fiber probe optimum design light transmission test Zemax optical simulation

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Strategy evaluation and optimization with an artificial society toward a Pareto optimum

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The Innovation 2022年第5期3卷 33-35页

作者： Zhengqiu Zhu Bin Chen Hailiang Chen Sihang Qiu Changjun Fan Yong Zhao Runkang Guo Chuan Ai Zhong Liu Zhiming Zhao Liqun Fang Xin Lu College of Systems Engineering National University of Defense TechnologyChangsha 410073China Hunan Institute of Advanced Technology Changsha 410073China Research Group of Multiscale Networked Systems University of Amsterdam(UvA)1099 Amsterdamthe Netherlands State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and EpidemiologyBeijing 100071China Department of Global Public Health Karolinska Institutet17177 StockholmSweden

Strategy evaluation and optimization in response to troubling urban issues has become a challenging issue due to increasing social uncertainty,unreliable predictions,and poor decision-making.To address this problem,we propose a universal computational experiment framework with a fine-grained artificial society that is integrated with data-based models.The purpose of the framework is to evaluate the consequences of various combinations of strategies geared towards reaching a Pareto optimum with regards to efficacy versus costs.As an example,by modeling coronavirus disease 2019 mitigation,we show that Pareto frontier nations could achieve better economic growth and more effective epidemic control through the analysis of real-world data.Our work suggests that a nation’s intervention strategy could be optimized based on the measures adopted by Pareto frontier nations through large-scale computational experiments.Our solution has been validated for epidemic control,and it can be generalized to other urban issues as well.

关键词： artificial optimization optimum

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