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Rotary axis calculation for five-axis FDM printer using a point-fitting optimization method

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Applied Mathematics(A Journal of Chinese Universities) 2022年第2期37卷 258-271页

作者： LIU hao LIU lei SHEN Kai College of Mechanical and Electrical Engineering Nanjing University of Aeronatics and AstronaticsNanjing 210016China

This paper presents an optimization method to compute the rotary axes of a 5-axis FDM printer whose A-and C-axes have large deviations relative to the x-and *** optimization model is designed according to the kinematic model in which a point rotates around a spatial line in the machine coordinate system of the *** model considers the A-and C-axes as two spatial *** is a two-object optimization model including two *** is that the sum of deviations between the measured and computed points should be small;the other is that the deviations should be uniformly distributed for every measured point.A comparison of the new optimization method with conventional error-compensation methods reveals that the former has higher location *** the optimized AC axes,5-axis 3D printing paths are planned for some complex *** analysis and printing samples show that the optimized AC axes satisfy 5-axes FDM printing requirements for nozzles with a diameter of 1.0 mm.

关键词： 3D printing five-axis rotary table location error error calibration

Novel E2E-QoE Metric for PHY Optimization:A Cross-Layered Framework

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China Communications 2023年第4期20卷 167-179页

作者： lei Ji hao Wang Hongxiang Xie Huawei No.156.Beiqing RoadHaidian DistrictBeijing 100095China

Existing systems use key performance indicators(KPIs)as metrics for physical layer(PHY)optimization,which suffers from the problem of overoptimization,because some unnecessary PHY enhancements are imperceptible to terminal users and thus induce additional cost and energy ***,it is necessary to utilize directly the quality of experience(QoE)of user as a metric of optimization,which can achieve the global optimum of QoE under cost and energy ***,QoE is still a metric of application layer that cannot be easily used to design and optimize the *** address this problem,we in this paper propose a novel end-to-end QoE(E2E-QoE)based optimization architecture at the user-side for the first ***,a cross-layer parameterized model is proposed to establish the relationship between PHY and *** on this,an E2E-QoE oriented PHY anomaly diagnosis method is further designed to locate the time and root cause of ***,we investigate to optimize the PHY algorithm directly based on the *** proposed frameworks and algorithms are all validated using the data from real fifth-generation(5G)mobile system,which show that using E2E-QoE as the metric of PHY optimization is feasible and can outperform existing schemes.

关键词： quality of experience(QoE) performance metric physical layer optimization cross-layer framework

Functional Peptides from One-bead One-compound High-throughput Screening Technique

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Chemical Research in Chinese Universities 2023年第1期39卷 83-91页

作者： YAN Yaqiong WANG lei WANG hao CAS Center for Excellence in Nanoscience CAS Key Laboratory for Biomedical Effects of Nanomaterials and NanosafetyNational Center for Nanoscience and Technology(NCNST)Beijing100190P.R.China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049P.R.China

Combinatorial chemistry provides a cost-effective method for the rapid discovery of new functional ***-bead one-compound(OBOC)high-throughput screening technique offers a lot of structurally diverse peptides to be rapidly synthesized and screened for binding to a target of *** OBOC peptide library screening involves three main steps:library construction,positive beads separation,and peptide *** review mainly summarizes some special technique tips during functional peptide screening and potential future directions of the OBOC high-throughput screening technique.

关键词： Combinatorial chemistry One-bead one-compound(OBOC) Cyclic peptide Peptide screening Self-assembly

Investigation on UV-curing Reprocessable Thermosets Bearing Hindered Urea Bonds and Their Composites with Modified Zinc Oxide Nanoparticles

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Chinese Journal of Polymer Science 2024年第6期42卷 751-765页

作者： jun-hao Zhou Li-Ming Tang Key Laboratory of Advanced Materials of Ministry of Education of China Department of Chemical EngineeringTsinghua UniversityBeijing100084China

In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot *** prepolymers were characterized fully by various ***,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and *** from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical ***,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their *** influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then *** composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT *** addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.

关键词： Polyurethane-urea methacrylate Hindered urea bond ZnO nanoparticles Reprocessing UV curing

Infection density pattern of Cardinium affects the responses of bacterial communities in an invasive whitefly under heat conditions

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Insect Science 2023年第4期30卷 1149-1164页

作者： Kun Yang Peng-hao Qin Meng-Ying Yuan lei Chen You-jun Zhang Dong Chu Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management College of Plant Health and MedicineQingdao Agricultural UniversityQingdaoShandong ProvinceChina Department of Entomology Nanjing Agricultural UniversityNanjingChina Department of Plant Protection Institute of Vegetables and FlowersChinese Academy of Agricultural SciencesBejingChina

Communities of bacteria,especially symbionts,are vital for the growth and development of insects and other arthropods,including Bemisia tabaci Mediterranean(MED),a destructive and invasive insect ***,the infection density patterns and influence factors of bacteria in whiteflies,which mainly include symbionts,remain largely *** reveal the different density patterns of Cardinium in *** MED popula-tions and the impacts of high temperatures on whiteflies with different Cardinium density infection patterns,2 isofemale lines isolated from *** MED from the same geo-graphical population of China and from *** MED collected from other countries and locations were examined using several techniques and methods,including fluorescence in situ hybridization(FISH),quantitative real-time polymerase chain reaction(qPCR),16S rRNA gene sequencing,and 2b-RAD *** results showed that there were 2 different infection density patterns of Cardinium in *** MED(including 1 high-density pattern and 1 low-density pattern).For whiteflies with low-density Cardinium,conventional PCR could not detect Cardinium,but the other techniques confirmed that there was a low level of Cardinium within *** temperature significantly decreased the diversity of bacterial communities:the relative titer of Cardinium increased but the density of Rickettsia decreased in the isofemale line with high-density ***-ever,high temperature did not influence the diversity and symbiont density in the line with low-density ***,high temperature influenced the functions of bacterial communities in whiteflies with high-density Cardinium but did not affect the bacterial functions in whiteflies with low-density *** results provide novel insights into the complex associations between symbionts and host insects.

关键词： bacterial communities Bemisia tabaci MED Cardinium heat stress infec-tion density pattern

Study on Agrobacterium-Mediated Transformation of Pepper with Barnase and Cre Gene

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Agricultural Sciences in China 2009年第8期8卷 947-955页

作者： LIU Juan-xu YU Yi-xun lei Jian-jun CHEN Guo-ju CAO Bi-hao College of Horticulture South China Agricultural University Guangzhou 510642 P.R. China Mid-Florida Research and Education Center Institute of Food and Agricultural Sciences University of Florida Apopka FL 32703-8504 USA

This study was designed to control plant fertility by cell lethal gene Barnase expressing at specific developmental stage and in specific tissue of male organ under the control of Cre/lox system, for heterosis breeding of chili pepper （Capsicum annuum L.）. Chili pepper inbred lines （A, D, E, and I） were transformed with Cre gene and Barnase gene situated between loxp, separately, by means of Agrobacterium co-culture. In this study, we had established a high transformation system by extensive study of affecting factors including genotype, selection of marker, and lethal dose. Cotyledon with petiole from 9-11-day-old seeding was pre-cultured on media MR[MB（MS mineral＋vitamine B5）＋BA（6-Benzyladenine） 5.0 mg·L^-1 ＋IAA（indoleacetic acid） 1.0 mg·L^-1＋GA3（gibberellic acid） 1.0mg·L^-1＋sucrose 3%＋agar 6.5g·L^-1] for 2d. The explants were infected by Agrobacterium tumefaciens when their OD600（optical density at 600 nm）reached 0.6-0.9. After co-cultured for 4-5 d on media MC [MB＋BA5.0 mg·L^-1＋IAA 1.0 mg·L^-1 ＋GA3 1.0 mg·L^-1＋sucrose 3% ＋agar 6.5 g·L^-1＋AS （acetosyringone） 200μmol·L^-1, these cotyledons with petiole were cultured on selective differentiation medium in the media MT[MB medium supplemented with BA [5.0 mg·L^-1＋ IAA 1.0 mg·L^-1＋ GA3 1.0 mg·L^-1＋ AgNO3 5.0 mg·L^-1＋ CW （coconut water） 5% ＋ Km （kanamycin） 65 mg·L^-1＋ Cb （carbenicillin） 500 mg·L^-1＋ 3% sucrose ＋ agar 6.5 g·L^-1].The Kmr （kanamycin resistant） bud rosettes were elongated on selective elongation medium and rooted on rooting medium. PCR and Southern blotting analysis of Kmr plantlet indicated that the foreign genes had been integrated into the genome of pepper. The transgenic plants with Cre gene developed well, blossomed out, and set fruit normally. The transgenic plants with Barnase gene grew well with normal appearance of flower, but they showed different fertility from complete sterility, partial sterility to complete fertility, and similar results were obtained from in vitro pollen germination experim

关键词： pepper (Capsicum annuum L.) genetic transformation male sterile TA29-Barnase Cre/lox system

A data transmission scheduling algorithm for rapid-response earth-observing operations

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Chinese Journal of Aeronautics 2014年第2期27卷 349-364页

作者： Li jun Li jun Chen hao Jing Ning College of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China Unit 61726 PLA Wuhan 430074 China

With the development of rapid-response Earth-observing techniques, the demand for reducing a requirements-tasking-effects cycle from 1 day to hours grows rapidly. For instance, a satellite user always wants to receive requested data in near real-time to support their urgent mis- sions, such as dealing with wildfires, volcanoes, flooding events, etc. In this paper, we try to reduce data transmission time for achieving this goal. The new feature of a responsive satellite is that users can receive signals from it directly. Therefore, the traditional satellite control and operational tech- niques need to be improved to accommodate these changes in user needs and technical upgrading. With that in mind, a data transmission topological model is constructed. Based on this model, we can deal with the satellite data transmission problem as a multi-constraint and multi-objective path- scheduling problem. However, there are many optional data transmission paths for each target based on this model, and the shortest path is preferred. In addition, satellites represent scarce resources that must be carefully scheduled in order to satisfy as many consumer requests as possible. To efficiently balance response time and resource utilization, a K-shortest path genetic algorithm is proposed for solving the data transmission problem. Simulations and analysis show the feasibility and the adaptability of the proposed approach.

关键词： Data transmission in nearreal-time Genetic algorithm K-shortest path Operationally responsivespace Remote sensing Scheduling

Real-time online rescheduling for multiple agile satellites with emergent tasks

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Journal of Systems Engineering and Electronics 2021年第6期32卷 1407-1420页

作者： WEN jun LIU Xiaolu HE lei College of Systems Engineering National University of Defense TechnologyChangsha 410073China

The emergent task is a kind of uncertain event that satellite systems often encounter in the application *** this paper,the multi-satellite distributed coordinating and scheduling problem considering emergent tasks is *** to the limitation of onboard computational resources and time,common online onboard rescheduling methods for such problems usually adopt simple greedy methods,sacrificing the solution quality to deliver timely *** better solve the problem,a new multi-satellite onboard scheduling and coordinating framework based on multi-solution integration is *** method uses high computational power on the ground and generates multiple solutions,changing the complex onboard rescheduling problem to a solution selection *** this method,it is possible that little time is used to generate a solution that is as good as the solutions on the *** further propose several multi-satellite coordination methods based on the multi-agent Markov decision process(MMDP)and mixed-integer programming(MIP).These methods enable the satellite to make independent decisions and produce high-quality *** with the traditional centralized scheduling method,the proposed distributed method reduces the cost of satellite communication and increases the response speed for emergent *** experiments show that the proposed multi-solution integration framework and the distributed coordinating strategies are efficient and effective for onboard scheduling considering emergent tasks.

关键词： agile satellite scheduling emergent task onboard rescheduling distributed coordinating multi-solution integration

Surface pattern based on an azobenzene-containing copolymer thin film and its light-driven morphology modulation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第7期14卷 504-513页

作者： lei ZHANG Li WANG hao-jie YU State Key Laboratory of Chemical Engineering Department of Chemical and Biological Engineering Zhejiang University

A type of azobenzene-containing block copolymer polymethyl methacrylate-b-poly (n-butylmethacrylate-co-6-(4-(phenylazo) benzoate) hexyl methacrylate) (PMMA-b-(PnBMA-co-PAzoMA)) was synthesized by the atom transfer radical polymerization (ATRP). Macroinitiator polymethyl methacrylate (PMMA) was prepared by ATRP and used to initiate the copolymerization of monomer n-butyl methacrylate (nBMA) and azobenzene-based methacrylate monomer (AzoMA). Herein, three block copolymers with different molecular weights and block volume fractions were obtained and spin-coated on a silicon substrate or quartz plate before annealing at 180℃ for 14 h. The surface morphologies in these annealed copolymer films were observed by atomic force microscopy (AFM). Bicontinuous stripe or island patterns with different sizes were formed dependent on the film thickness. These ordered patterns are considered to be formed arising from the dewetting process of the surface layer in the copolymer film. Photoisomerization of azobenzene units in the copolymer films changed the dewetting behaviors of the surface layer of the thin film. Therefore, some copolymer annealed films showed a reversible morphology conversion between bicontinuous stripe and island structure when exposed to UV light and upon being stored in the dark. It was found that the composition of the block copolymer had obvious influences on the photoinduced morphology conversion behaviors in these copolymer thin films. When the volumes of PnBMA and PAzoMA phases in the block copolymer were large enough, the surface morphology could be modulated by UV light irradiation and storage in the dark. This work proposes a new possibility for photoinduced control and design of the dewetting processes of thin films using a linear block copolymer.

关键词： Dewetting behavior Photoinduced morphology modulation Atom transfer radical polymerization (ATRP) Block copolymer