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An uncertainty investigation for liner impedance eduction methods

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chinese Journal of Aeronautics 2024年第3期37卷 49-59页

作者： Weihao shi Xiaodong JING school of Energy and Power Engineering Beihang UniversityBeijing 100191China

Impedance eduction methods have been developed for decades to meet the increasing need for high-quality impedance data in the design and optimization of acoustic *** this end,it is important to fully investigate the uncertainty problem,to which only limited attention has been devoted so *** paper considers the possibility of acoustically-induced structural vibration as a nonnegligible uncertainty or error source in impedance eduction *** the frequency moves away from the resonant frequency,with the increase in the value of cavity reactance,the acoustic particle velocity inside liner orifices possibly decreases to the extent comparable to the vibration velocity of liner facing ***,the acoustically-induced vibration,although generally being weak except at the inherent structural frequencies,may considerably affect the impedance eduction results near the anti-resonant frequency where the liner has poor *** demonstrate the effect of structural vibration,the vibration velocity of liner facing sheet is estimated from the experimentally educed admittance of the liner samples whose orifices are sealed with ***,a three-dimensional numerical model is set up,in which normal particle velocity is introduced over the solid portion of liner facing sheet to imitate structural vibration,rather than directly solving the acoustic-structural coupling *** shown by the results,the vibration of liner facing sheet,whose velocity is as small as estimated by the experiment,can result in anomalous deviation of the educed impedance from the impedance model near the anti-resonant *** trend that the anomalous deviation varies with frequency is numerically captured.

关键词： Impedance eduction Uncertainty analysis Acoustically-induced structural vibration Anti-resonant frequency Perforated liner

Microstructure and Properties of W-15Cu Alloys Prepared by Mechanical Alloying and spark Plasma sintering Process

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Journal of Wuhan university of technology(Materials science) 2008年第3期23卷 399-402页

作者：章桥新 school of Mechanical and Electronic Engineering Wuhan University of Technology state Key Laboratory of Advanced technology for Materials synthesis&Processing Wuhan University of TechnologyWuhan 430070China

W-15Cu composite powders prepared by mechanical alloying （MA） of raw powders were consolidated by spark plasma sintering （sPs） process at temperature ranged 1 230-1 300 ℃ for 10 min and under a pressure of 30 MPa. By using high energy milling, particles containing very fine tungsten grains embedded in copper, called composite particles, could be produced. The W grains were homogeneously dispersed in copper phase, which was very important to obtain W-Cu alloy with high mechanical properties, fine and homogeneous microstructure. The microstructure and properties of W-15Cu alloys prepared by sPs processes at different temperature were researched. The results show that W-15Cu alloys consolidated by sPs can reach 99.6 % relative density, and transverse rupture strength （TRs） is 1 400.9 MPa, Rockwell C hardness （HRC） is 45.2, the thermal conductivity is 196 W/m-K at room temperature, the average grain size is less than 2 μm, and W-15Cu alloy with excellent properties, homogeneous and fine microstructure is obtained.

关键词： W-15Cu mechanical alloying spark plasma sintering (sPs)

short exposure to paclitaxel induces multipolar spindle formation and aneuploidy through promotion of acentrosomal pole assembly

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science china(Life sciences) 2010年第11期53卷 1322-1329页

作者： BIAN MingLei1, FU JingYan1, YAN Yan1, CHEN Qiang1, YANG Chao2, shi QingHua2,JIANG Qing1 & ZHANG ChuanMao1 1MOE Key Laboratory of Cell Proliferation and Differentiation and the state Key Laboratory of Bio-membrane and Membrane Bio-engineering, College of Life sciences, Peking university, beijing 100871, china 2Hefei National Laboratory for Physical sciences at Microscale and school of Life sciences, university of science and technology of china, Hefei 230026, china 1. MOE Key Laboratory of Cell Proliferation and Differentiation and the state Key Laboratory of Bio-membrane and Membrane Bio-engineering College of Life Sciences Peking University Beijing 100871 China2. Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences University of Science and Technology of China Hefei 230026 China

Paclitaxel is a widely used microtubule drug and cancer medicine. Here we report that by short exposure to paclitaxel at a low dose, multipolar spindles were induced in mitotic cells without centrosome amplification. Both TPX2 depletion and Aurora-A overexpression antagonized the multipolarity. Live cell imaging showed that some paclitaxel-treated cells accomplished multipolar cell division and a portion of the daughter cells went on to the next round of mitosis. The surviving cells grew into clones with varied genome content. The results indicated that an aneuploidy population could be induced by short exposure to paclitaxel at a low dose, implicating potential side effects of paclitaxel.

关键词： paclitaxel tpx2 Aurora-A multipolar cell division aneuploidy

Adaptive space Expansion for Fast Motion Planning

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IEEE/CAA Journal of Automatica sinica 2024年第6期11卷 1499-1514页

作者： shenglei shi Jiankui Chen state Key Laboratory of Digital Manufacturing Equipment and technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning *** this paper,we pro-pose an adaptive space expansion(AsE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible *** AsE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary ***,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is ***,the AsE method successively does space exploring and space expan-sion until the final path has been ***,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in *** last,we present a feasible motion planner BiAsE and an asymptoti-cally optimal motion planner BiAsE*using the bidirectional exploring method and the AsE *** demon-strate that the computation speed is much faster than that of the state-of-the-art *** source codes are available at https://***/shshlei/ompl.

关键词： Adaptive space expansion(AsE) hyper-ellipsoid ring informed sampling motion planning.

Comparative analysis of 12 water lily plastid genomes reveals genomic divergence and evolutionary relationships in early flowering plants

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Marine Life science & technology 2024年第3期6卷 425-441页

作者： Weicai song Wenbo shi Huan Wang Zirui Zhang Ruiqing Tao Jin Liu shuo Wang Michael s.Engel Chao shi College of Marine science and Biological Engineering Qingdao University of Science and TechnologyQingdao 266042China Plant Germplasm and Genomics Center Germplasm Bank of Wild Species in Southwest ChinaKunming Institute of BotanyThe Chinese Academy of SciencesKunming 650204China Yunnan Institute of Tropical Crops Xishuangbanna 666100China American Museum of Natural History New YorkNY 10024-5192USA Natural History Museum and Department of Ecology&Evolutionary BiologyUniversity of KansasLawrenceKS 66045USA

The aquatic plant Nymphaea,a model genus of the early flowering plant lineage Nymphaeales and family Nymphaeaceae,has been extensively ***,the availability of chloroplast genome data for this genus is incomplete,and phylogenetic relationships within the order Nymphaeales remain *** this study,12 chloroplast genomes of Nymphaea were assembled and analyzed for the first *** genomes were 158,290-160,042 bp in size and contained 113 non-repeat genes,including 79 protein-coding genes,30 tRNA genes,and four rRNA *** also report on codon usage,RNA editing sites,microsatellite structures,and new repetitive sequences in this *** genomics revealed that expansion and contraction of IR regions can lead to changes in the gene ***,it was observed that the highly variable regions of the chloroplast genome were mainly located in intergenic ***,the phylogenetic tree showed the order Nymphaeales was divided into three families,and the genus Nymphaea can be divided into five(or three)subgenera,with the subgenus Nymphaea being the *** divergence times of nymphaealean taxa were analyzed,with origins of the order Nymphaeales and family Nymphaeaceae being about 194 and 131 million years,*** results of the phylo-genetic analysis and estimated divergence times will be useful for future evolutionary studies of basal angiosperm lineages.

关键词： Aquatic plants Nymphaea Phylogenetic analysis Plastid genomics structural variation

Families of schmidt-number witnesses for high dimensional quantum states

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Communications in Theoretical Physics 2024年第8期76卷 44-51页

作者： Xian shi College of Information science and technology Beijing University of Chemical TechnologyBeijing 100029China

Higher dimensional entangled states demonstrate significant advantages in quantum information processing tasks. The schmidt number is a quantity of the entanglement dimension of a bipartite state. Here we build families of k-positive maps from the symmetric information complete positive operator-valued measurements and mutually unbiased bases, and we also present the schmidt number witnesses, correspondingly. At last, based on the witnesses obtained from mutually unbiased bases, we show the distance between a bipartite state and the set of states with a schmidt number less than k.

关键词： schmidt number entanglement witness mutually unbiased bases

Fabrication and Characterization of Nano silver Powder Prepared by spray Pyrolysis

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Journal of Wuhan university of technology(Materials science) 2009年第6期24卷 871-874页

silver powder was fabricated by spray pyrolysis, using 2%-20% AgNO3 solution, 336-500 mL/h flux of AgNO3 solution, 0.28-0.32 MPa flux of carrier gas and in the 620-820 ℃ temperature range. The effects of furnace set temperature, concentration of AgNO3 aqueous solution, flux of AgNO3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder, were investigated. The experimental results showed that with the high concentration of AgNO3 aqueous solution, the average grain size of silver decreased with the increasing of furnace set temperature. But the gain size distribution was not homogenous, the discontinuous grain growth occurred. With the low concentration of AgNO3 aqueous solution, the higher furnace set temperature made the nano sliver grains sintered together to grow. Nano silver powder about 100 nm was fabricated by spray pyrolysis, using 2wt% AgNO3 solutions, 336 mL/h flux of AgNO3 aqueous solution, 0.32 MPa flux of carrier gas at 720 ℃ furnace set temperature.

关键词： nano silver powder fabrication characterization spray pyrolysis

Mechanical and Experimental study of sprinkling Water Cooling system on Roof of shanghai Expo Theme Pavilion

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湖南大学学报（自然科学版） 2009年第S1期36卷 156-159页

作者： ZHAO Hui-zhong1,HUANG Chen1,LI Wei-xiang2,shi Jin-yue2,TAO si-yuan1,WANG Qian1,WANG Yu-qing1,ZHANG Min3(1.College of Urban Construction and Environment Engineering,university of shanghai for science and technology,shanghai 200093,china 2.Architectural Design & Research Institute of Tongji university,shanghai 200092,china 3.College of Food science technology,shanghai Ocean university,shanghai 201306,china) College of Urban Construction and Environment Engineering University of Shanghai for Science and Technology Shanghai 200093 China Architectural Design and Research Institute Tongji University Shanghai 200092 China College of Food science technology Shanghai Ocean University Shanghai 201306 China

Based on the similarity theory,a scale effect model of the spraying water cooling system of shanghai expo Theme Pavilion's roof was set *** to the typical weather conditions in shanghai city,different models were analyzed on solar radiation,and different heat transfer amount was *** the following conclusions could be made:At the sunny day of summer in shanghai,the temperature of inner roof with sprinkling system descended about 3 ℃,and the air conditioning load of the whole Theme Pavilion descend more than 320 kW.

关键词： shanghai expo large space atrium solar radiation roof sprinkling system similarity theory prototype

New ancient DNA sequences suggest high genetic diversity for the woolly mammoth (Mammuthus primigenius)

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Progress in Natural science:Materials International 2006年第4期16卷 379-386页

作者： YANG shujuan, LAI Xulong, shi suhua, CHENG shenghong, ZHOU Xiugao, YANG Xiujuan and YANG Hong Department of Earth science, china university of Geosciences, Wuhan 430074, china Department of Life science, sun Yat-sen university, Guangzhou 510275, china Institute of Zoology, chinese academy of sciences, beijing 100080, china Heilongjiang Provincial Museum, Harbin 150001, china Department of sciences and technology, College of Arts and sciences, Bryant university, smithfield, Rhode Island 02917, UsA and Department of Geology and Geophysics, Yale university, New Haven, CT 06520, UsA [a]Department of Earth science China University of Geosciences Wuhan China [b]Institute of Zoology Chinese Academy of Sciences Beijing China [c]Department of Life sceince Sun Yat-Sen University Guangzhou China [d]Heilongjiang Provincial Museum Harbin China [e]Department of sciences and technology College of Arts and Sciences Bryant University Smithfield Rhode Island USA [f]Department of Geology and Geophysics Yale University New Haven CT USA

Partial DNA sequences of cytochrome b gene (mtDNA) were successfully retrieved from Late Pleistocene fossil bone of Mammuthus primigenius collected from the Xiguitu County ( Yakeshi), Inner Mongolia Autonomous Region and from Zhaodong, Harbin of Heilongjiang Province in northern china. Two ancient DNA fragments (109 bp and 124 bp) were authenticated by reproducible experiments in two different laboratories and by phylogenetic analysis with other Elephantidae taxa. Phylogenetic analysis using these sequences and published data in either separate or combined datasets indicate unstable relationship among the woolly mammoth and the two living elephants, Elephas and Loxodonta . In addition to the short sequences used to attempt the long independent evolution of Elephantidae terminal taxa, we suggest that a high intra-specific diversity existed in Mammuthus primigenius crossing both spatial and temporal ranges, resulting in a complex and divergent genetic background for DNA sequences so far recovered. The high genetic diversity in the extinct woolly mammoth can explain the apparent instability of Elephantidae taxa on the molecular phylogenetic trees and can reconcile the apparent paradox regarding the unresolved Elephantidae trichotomy.

关键词： Mammuthus primigenius genetic diversity ancient DNA phylogenetic analysis.