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Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated martian atmosphere

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Acta Mechanica Sinica 2012年第5期28卷 1296-1302页

作者： xin Lin xi-long yu Fei Li Shao-Hua Zhang Jian-Guo xin xin-yu Zhang School of Optoelectronics Beijing Institute of Technology State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of Sciences

Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- resolved spectra of the Av = 0 sequence of the B^2∑^＋ → X^2∑^＋ electronic transition of CN have been observed through optical emission spectroscopy （OES）. A new method, which is based on fitting high resolution spectrum for rotational and vibrational temperatures measurement, is proposed to diag- nose temperature distribution behind the shock wave. It is estimated that the current scheme has the maximum deviation less than 8% （lσ） for vibrational temperature measurement through detailed analysis of the influence of the uncertainties of spectroscopic constants and spectral resolution. Radiation structure of the shock layer, including induction, relaxation and equilibrium process, and corresponding rotational and vibrational temperatures are obtained through time gating OES diagnostics with sub-microsecond temporal resolution. The present extensive results will strongly benefit the reaction rate estimation and computational fluid dynamics （CFD） code validation in high enthalpy Mars reentry chemistry.

关键词： Radiation measurements - Shock wave Marsre-entry Rotational temperature Vibrational temperature

Estimating energy release performance of oxidizer-activated aluminum fuel particles under ultrafast stimulus

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Defence Technology（防务技术） 2023年第5期23卷 92-99页

作者： Ya-ru Li Hui Ren xin-zhou Wu Hui-xin Wang xi-long yu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.

关键词： Aluminum Glycidyl azide polymer Laser Detonation Explosive Ultrafast stimulus

The Research on the Regulation to the Compensated Utilization of the Resource Assets in Telecommunication Service Industry: Wireless Frequency as a Study Case

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The Journal of China Universities of Posts and Telecommunications 2003年第2期10卷 56-61页

作者： long xiao yu (xi’an Institute of Posts and Telecommunications, xi’an 710061, P.R.China) xi'an Institute of Posts and Telecommunications Xi'an 710061

This Paper focuses on the compensated utilization of resource assets such aswireless frequency. It supplies the methods of estimating value of resource assets based on theanalysis of its characteristics. It also analyzes the compensated policy-making and its affects onthe Telecommunication Service Providers (TSP) performance gained by using resource assets. Theresults of the research indicate that the compensated utilization will promote the TSP to improvetheir economic efficiency, and aid to build a fairer competitive environment in TelecommunicationService Industry (TSI) in China.

关键词： resource assets compensated utilization TSI

Transmission characteristics of EM wave in a finite thickness plasma

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Acta Mechanica Sinica 2013年第2期29卷 189-195页

作者： Nai-Yi Zhu Li-Shun Huang Bin Wu xi-long yu Run-Hui Wu Gang Meng Ai-Min Ren xin-Tian Hu State Key Lab of High Temperature Gas Dynamics(LHD) Institute of MechanicsChinese Academy of Sciences State Key Lab of Experimental Physics and Computational Mathematics China Aerospace Technology Corporation

One of the key factors for solving the problems of re-entry communication interruption is electromagnetic（EM） wave transmission characteristics in a *** and experimental studies were carried out on specific transmission characteristics for different plasma sheath characteristic under thin sheath condition in re-entry *** paper presents systematic studies on the variations of wave attenuation characteristics versus plasma sheath thickness L,collision frequency ν,electron density n e and wave working frequency f in a φ 800 mm high temperature shock *** experiments,L is set to 4 cm and 38 cm.ν is 2 GHz and 15 GHz.n e is from 1×10 10 cm（-3） to 1×10 13 cm（-3）,and f is set to 2,5,10,14.6 GHz,***,Wentzel-Kramers-Brillouin（WKB） and finite-difference time-domain（FDTD） methods are adopted to carry out theoretical simulation for comparison with experimental *** is found that when L is much larger than EM wavelength λ（thick sheath） and ν is large,the theoretical result is in good agreement with experimental one,when sheath thickness L is much larger than λ,while ν is relatively small,two theoretical results are obviously different from the experimental *** means that the existing theoretical model can not fully describe the contribution of ν.Furthermore,when L and λ are of the same order of magnitude（thin sheath）,the experimental result is much smaller than the theoretical values,which indicates that the current model can not properly describe the thin sheath effect on EM attenuation characteristics.

关键词： Plasma·Electromagnetic wave·Shock tube·Numerical simulation

Genome Assembly of Alfalfa Cultivar Zhongmu-4 and Identification of SNPs Associated with Agronomic Traits

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Genomics, Proteomics & Bioinformatics 2022年第1期20卷 14-28页

作者： Ruicai long Fan Zhang Zhiwu Zhang Mingna Li Lin Chen Xue Wang Wenwen Liu Tiejun Zhang long-xi yu Fei He Xueqian Jiang xijiang Yang Changfu Yang Zhen Wang Junmei Kang Qingchuan Yang Institute of Animal Sciences Chinese Academy of Agricultural SciencesBeijing 100193China Department of Crop and Soil Sciences Washington State UniversityPullmanWA 99163USA School of Grassland Science Beijing Forestry UniversityBeijing 100083China United States Department of Agriculture-Agricultural Research Service Plant and Germplasm Introduction and Testing ResearchProsserWA 99350USA

Alfalfa(Medicago sativa L.)is the most important legume forage crop worldwide with high nutritional value and *** a long time,the breeding of alfalfa was hampered by lacking reliable information on the autotetraploid genome and molecular markers linked to important agronomic *** herein reported the de novo assembly of the allele-aware chromosome-level genome of Zhongmu-4,a cultivar widely cultivated in China,and a comprehensive database of genomic variations based on resequencing of 220 *** 2.74 Gb contigs(N50 of 2.06 Mb),accounting for 88.39%of the estimated genome,were assembled,and 2.56 Gb contigs were anchored to 32 pseudo-chromosomes.A total of 34,922 allelic genes were identified from the allele-aware *** observed the expansion of gene families,especially those related to the nitrogen metabolism,and the increase of repetitive elements including transposable elements,which probably resulted in the increase of Zhongmu-4 genome compared with Medicago *** structure analysis revealed that the accessions from Asia and South America had relatively lower genetic diversity than those from Europe,suggesting that geography may influence alfalfa genetic divergence during local ***-wide association studies identified 101 single nucleotide polymorphisms(SNPs)associated with 27 agronomic *** candidate genes were predicted to be correlated with fall dormancy and salt *** believe that the alleleaware chromosome-level genome sequence of Zhongmu-4 combined with the resequencing data of the diverse alfalfa germplasms will facilitate genetic research and genomics-assisted breeding in variety improvement of alfalfa.

关键词： Alfalfa Autotetraploid Genome assembly Resequencing Genome-wide association study

A Study of Liabilities Scale in Telecommunication Enterprises

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The Journal of China Universities of Posts and Telecommunications 2000年第4期7卷 57-61页

作者： XUE Rong na, long xiao yu (xian University of Posts and Telecommunications, xian 710061, P.R. China) xi'an University of Posts and Telecommunications Xi'an 710061 P.R. China

The paper analyzes the benefit and risk of liabilities operation in telecom enterprises and the advantages of internal and external conditions in liabilities operation. The quantitative model of liabilities scale is s... 详细信息

关键词： telecom enterprise liabilities operation liabilities scX

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新冠疫情对居民休闲出行影响研究

中国公路学报 2022年第1期35卷 238-251页

作者：石京龙昱茜清华大学土木工程系北京100084

为了就新冠疫情对疫情结束后居民休闲出行的影响展开调查研究,把握疫情后居民休闲出行偏好的变化,分析休闲出行意愿的影响因素和影响机制,并量化分析各因素的影响,基于计划行为理论和收益-风险分析构建结构方程模型,量化感知风险、感知... 详细信息

为了就新冠疫情对疫情结束后居民休闲出行的影响展开调查研究,把握疫情后居民休闲出行偏好的变化,分析休闲出行意愿的影响因素和影响机制,并量化分析各因素的影响,基于计划行为理论和收益-风险分析构建结构方程模型,量化感知风险、感知正效用、出行态度、主观规范、感知行为控制等影响因素与疫情后休闲出行意愿的相互影响机制,并利用单因素方差分析法和独立样本T检验分析不同性别、年龄段、收入水平的居民受影响的差异。研究结果表明:结构方程模型的卡方自由度比(CMIN/DF)为1.902,RMSEA值为0.047,证明模型具有良好的适配性;感知行为控制、态度和感知正效用会直接正向显著地影响人们在疫情后的出行意愿,总效应分别为0.391、0.608、0.296;主观规范则间接正向显著地影响出行意愿,总效应为0.621;对疫情风险的感知可能性会间接负向显著地影响人们的出行意愿,总效应为-0.081;新冠疫情会对居民休闲出行的偏好和特征产生显著的影响;以家庭为单位、以私家车为主要交通工具的自助游将在疫情后成为主要方式,逐步占领旅游市场;疫情对26岁以下的青年人和41~50岁的中年人、工作相对不稳定和低收入群体产生较大影响,这部分人感知到较低的出行效用和较高的阻抗,出行意愿偏低。研究结论将为后疫情时代旅游业的复苏刺激政策提供数据支撑和方向指引。

关键词：交通工程休闲出行结构方程模型影响机制计划行为理论收益-风险分析新型冠状病毒肺炎

Evolutionary genomics of climatic adaptation and resilience to climate change in alfalfa

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Molecular Plant 2024年第6期17卷 867-883页

作者： Fan Zhang Ruicai long Zhiyao Ma Hua xiao xiaodong Xu Zhongjie Liu Chunxue Wei Yiwen Wang Yanling Peng Xuanwen Yang xiaoya Shi Shuo Cao Mingna Li Ming Xu Fei He Xueqian Jiang Tiejun Zhang Zhen Wang xianran Li long-xi yu Junmei Kang Zhiwu Zhang Yongfeng Zhou Qingchuan Yang Institute of Animal Science Chinese Academy of Agricultural SciencesBeijing 100193China National Key Laboratory of Tropical Crop Breeding Shenzhen BranchGuangdong Laboratory of Lingnan Modern AgricultureKey Laboratory of Synthetic BiologyMinistry of Agriculture and Rural AffairsAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518000China School of Grassland Science Beijing Forestry UniversityBeijing 100083China Department of Agronomy and Horticulture University of Nebraska-LincolnLincolnNE 68583USA Department of Crop and Soil Sciences Washington State UniversityPullmanWA 99163USA U.S.Department of Agriculture-Agricultural Research Service Plant Germplasm Introduction and Testing ResearchProsserWA 99350USA National Key Laboratory of Tropical Crop Breeding Tropical Crops Genetic Resources InstituteChinese Academy of Tropical Agricultural SciencesHaikou 571101China

Given the escalating impact of climate change on agriculture and food security,gaining insights into the evolutionary dynamics of climatic adaptation and uncovering climate-adapted variation can empower the breeding of climate-resilient crops to face future climate ***(Medicago sativa ***),the queen of forages,shows remarkable adaptability across diverse global environments,making it an excellent model for investigating species responses to climate *** this study,we performed population genomic analyses using genome resequencing data from 702 accessions of 24 Medicago species to unravel alfalfa’s climatic adaptation and genetic susceptibility to future climate *** found that interspecific genetic exchange has contributed to the gene pool of alfalfa,particularly enriching defense and stress-response *** introgression between *** ***(***)and alfalfa not only aids alfalfa’s climatic adaptation but also introduces genetic burden.A total of 1671 genes were associated with climatic adaptation,and 5.7%of them were introgressions from *** integrating climate-associated variants and climate data,we identified populations that are vulnerable to future climate change,particularly in higher latitudes of the Northern *** findings serve as a clarion call for targeted conservation initiatives and breeding *** also identified preadaptive populations that demonstrate heightened resilience to climate fluctuations,illuminating a pathway for future breeding ***,this study enhances our understanding about the local adaptation mechanisms of alfalfa and facilitates the breeding of climate-resilient alfalfa cultivars,contributing to effective agricultural strategies for facing future climate change.

关键词： Medicago local adaptation population genetics adaptive introgression genetic vulnerability alfalfa breeding

Multiparameter magnetic resonance imaging-based radiomics model for the prediction of rectal cancer metachronous liver metastasis

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World Journal of Gastrointestinal Oncology 2025年第1期17卷 62-72页

作者： Zhi-Da long xiao yu Zhi-xiang xing Rui Wang Department of Hepatobiliary and Pancreaticosplenic Surgery Jingzhou Hospital Affiliated to Yangtze UniversityJingzhou 434100Hubei ProvinceChina

BACKGROUND The liver,as the main target organ for hematogenous metastasis of colorectal cancer,early and accurate prediction of liver metastasis is crucial for the diagnosis and treatment of ***,this study aims to investigate the application value of a combined machine learning(ML)based model based on the multiparameter magnetic resonance imaging for prediction of rectal metachronous liver metastasis(MLM).AIM To investigate the efficacy of radiomics based on multiparametric magnetic resonance imaging images of preoperative first diagnosed rectal cancer in predicting MLM from rectal *** We retrospectively analyzed 301 patients with rectal cancer confirmed by surgical pathology at Jingzhou Central Hospital from January 2017 to December *** participants were randomly assigned to the training or validation queue in a 7:3 *** first apply generalized linear regression model(GLRM)and random forest model(RFM)algorithm to construct an MLM prediction model in the training queue,and evaluate the discriminative power of the MLM prediction model using area under curve(AUC)and decision curve analysis(DCA).Then,the robustness and generalizability of the MLM prediction model were evaluated based on the internal validation set between the validation queue *** Among the 301 patients included in the study,16.28%were ultimately diagnosed with MLM through pathological *** analysis showed that carcinoembryonic antigen,and magnetic resonance imaging radiomics were independent predictors of ***,the GLRM prediction model was developed with a comprehensive nomogram to achieve satisfactory *** prediction performance of GLRM in the training and validation queue was 0.765[95%confidence interval(CI):0.710-0.820]and 0.767(95%CI:0.712-0.822),*** with GLRM,RFM achieved superior performance with AUC of 0.919(95%CI:0.868-0.970)and 0.901(95%CI:0.850-0.952)in the training and validation queue,respect

关键词： Rectal cancer Metachronous liver metastases Magnetic resonance imaging Radiomics Machine learning