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棉花种质资源萌发期耐盐性鉴定及筛选

作物学报 2024年第5期50卷 1147-1157页

作者：李航刘丽黄乾刘文豪司爱君孔宪辉王旭文赵福相梅拥军余渝塔里木大学农学院新疆阿拉尔843300 新疆农垦科学院棉花研究所/农业农村部西北内陆区棉花生物学与遗传育种重点实验室新疆石河子832000

种子萌发期是对盐分较敏感的时期,测定不同盐浓度胁迫下的棉花种子发芽情况是筛选棉花耐盐种质的重要依据之一。本研究对629份棉花种质资源进行0、150 mmol L^(-1) NaCl处理,对鲜重、发芽势等6个性状的耐盐系数进行差异分析,结果显示盐... 详细信息

种子萌发期是对盐分较敏感的时期,测定不同盐浓度胁迫下的棉花种子发芽情况是筛选棉花耐盐种质的重要依据之一。本研究对629份棉花种质资源进行0、150 mmol L^(-1) NaCl处理,对鲜重、发芽势等6个性状的耐盐系数进行差异分析,结果显示盐胁迫下各个性状较对照均存在显著差异;使用主成分分析、隶属函数分析对棉花种质耐盐性进行综合评价;对综合评价值D值进行聚类分析,根据D值的大小将629份种质资源分成5类:188份耐盐中间型材料、376份耐盐型材料、36份高耐盐型材料、28份盐敏感型材料、1份高盐敏感型材料;通过逐步回归分析建立棉花萌发期耐盐性评价预测模型:D=0.277RFW+0.29RGP+0.189RPL+0.387RGR-0.32(R^(2)=0.992),筛选出鲜重、下胚轴长、发芽势和发芽率4个指标可作为棉花萌发期耐盐性鉴定的指标。本研究建立了一套精准、高效的耐盐性鉴定体系,筛选到36份高耐盐材料和1份高敏感材料,为棉花耐盐机制研究和培育耐盐新品种提供参考。

关键词：棉花萌发期耐盐性综合评价

核壳结构nAl@Cu(BTC)/Fe(BTC)纳米铝热剂的制备及燃烧性能

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含能材料 2024年第5期32卷 465-474页

作者：史喆赵媛媛马志伟杨玉林张健王旭文梁家燕中国五洲工程设计集团有限公司北京100053 哈尔滨工业大学化工与化学学院新能源转换与存储关键材料技术工业和信息化部重点实验室黑龙江哈尔滨150001

为了解决纳米铝热剂的制备工艺中组分分布不均匀和燃烧效率低等问题,采用层层组装技术将铜‐均苯三甲酸(Cu(BTC))和铁‐均苯三甲酸(Fe(BTC))交替包覆在nAl表面,制备核壳结构nAl@Cu(BTC)/Fe(BTC)纳米铝热剂,并对其结构、形貌、热反应性能... 详细信息

为了解决纳米铝热剂的制备工艺中组分分布不均匀和燃烧效率低等问题,采用层层组装技术将铜‐均苯三甲酸(Cu(BTC))和铁‐均苯三甲酸(Fe(BTC))交替包覆在nAl表面,制备核壳结构nAl@Cu(BTC)/Fe(BTC)纳米铝热剂,并对其结构、形貌、热反应性能(铝热反应温度)和燃烧性能(燃烧时间、点火延迟时间和燃烧温度等)进行研究。结果表明:层层组装技术可以调控包覆层的厚度和形貌,随着包覆层厚度的增加纳米铝热剂从粗糙疏松逐渐变得光滑致密;交替包覆12层Cu(BTC)/Fe(BTC)的纳米铝热剂燃烧剧烈,火焰传播速率较快,在0.710 s内火焰达到最大,具有适中的点火延迟时间(0.509 s)、最短的燃烧时间(2.036 s)和最高的燃烧温度(1425℃),此时,Cu(BTC)和Fe(BTC)的协同作用使其铝氧化反应温度峰值降低到552.5℃和735.0℃。

关键词：核壳结构纳米铝热剂 nAl@Cu(BTC)/Fe(BTC) 层层组装技术燃烧性能

Pulmonary embolism presenting as recurrent transient loss of consciousness： syncope and seizure

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Chinese Medical Journal 2013年第1期126卷 193-194页

作者： wang Jian-wen xu Ming-wei LUO Ben-yan Department of Neurology First Affiliated Hospital ZhejiangUniversity School of Medicine Hangzhou Zheiiang 310003China

Puhnonary embolism （PE） is a potentially lethal disease. Syncope or seizure as a presenting symptomof＇ PE is very difficult to diagnose. We report a patient with PI~ presenting recurrent transient loss of conscious... 详细信息

关键词： pulmonary embolism syncope seizure

Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and Electronics 2024年第1期35卷 65-73页

作者： wen Yi wang Junxiang xu Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing Institute of Aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems

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The Journal of China Universities of Posts and Telecommunications 2014年第1期21卷 116-121页

作者： SUN Yue-ping wang Xiao-jie wang xu-wen JIANG Shao-wei LIU Yong-bin School of Computer Science Beijing University of Posts and Telecommunications

Community-based question answer（CQA） makes a figure network in development of social network. Similar question retrieval is one of the most important tasks in CQA. Most of the previous works on similar question retrieval were given with the underlying assumption that answers are similar if their questions are similar, but no work was done by modeling similarity measure with the constraint of the assumption. A new method of modeling similarity measure is proposed by constraining the measure with the assumption, and employing ensemble learning to get a comprehensive measure which integrates different context features for similarity measuring, including lexical, syntactic, semantic and latent semantic. Experiments indicate that the integrated model could get a relatively high performance consistence between question set and answer set. Models with better consistency tend to get a better precision according to answers.

关键词： similar question retrieval similarity measure CQA ensemble learning

Rebels Lead to the Doctrine of the Mean: A Heterogeneous DeGroot Model

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Journal of Systems Science & Complexity 2018年第6期31卷 1498-1509页

作者： CAO Zhigang JIAO Fengliang QU Xinglong wang wen-xu YANG Mingmin YANG Xiaoguang ZHANG Boyu Department of Economics School of Economics and ManagementBeijing Jiaotong UniversityBeijing 100044China Department of Information Engineering Weifang Business Vocational CollegeZhucheng 262234China The Research Center of Information Technology &Economic and Social Development Hangzhou Dianzi UniversityHangzhou 310018China School of Systems Science Beijing Normal UniversityBeijing 100088China MADIS Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Laboratory of Mathematics and Complex Systems Ministry of EducationSchool of Mathematical SciencesBeijing Normal UniversityBeijing 100875China

The DeGroot model is one of the most classical models in the field of opinion dynamics. The standard DeGroot model assumes that agents are homogeneous and update their opinions in the direction of a weighted average of their neighbors'*** natural question is whether a second type of agents could significantly change the main properties of the *** authors address this question by introducing rebels,who update their opinions toward the opposite of their neighbors' weighted *** authors find that the existence of rebels remarkably affects the opinion dynamics. Under certain mild conditions,the existence of a few rebels will lead the group opinion to the golden mean,regardless of the initial opinions of the agents and the structure of the learning *** result is completely different from that of the standard DeGroot model,where the final consensus opinion is determined by both the initial opinions and the learning *** study then provides new insights into understanding how heterogeneous individuals in a group reach consensus and why the golden mean is so common in human society.

关键词： Golden mean network opinion dynamics rebel

河套灌区暗管外包滤料的透水效果及防淤堵性能研究

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中国农村水利水电 2024年第6期 209-216页

作者：胡玲玲杨树青王文旭张万锋马守良王波王伟郭富强内蒙古恒源水利工程有限公司内蒙古呼和浩特010010 内蒙古农业大学内蒙古呼和浩特010018 内蒙古鄂尔多斯市东胜区水利事业发展中心内蒙古鄂尔多斯017099 内蒙古师范大学内蒙古呼和浩特010022

为探究不同外包滤料条件下的暗管透水效果、保土和防淤堵性能,设置5种暗管外包滤料方案,分别为砂滤料(A)、68 g/m^(2)土工布(B)、90 g/m^(2)土工布(C)、68 g/m^(2)土工布+砂滤料(D),以及无外包滤料(E)方案作为对照,通过室内渗透试验,田... 详细信息

为探究不同外包滤料条件下的暗管透水效果、保土和防淤堵性能,设置5种暗管外包滤料方案,分别为砂滤料(A)、68 g/m^(2)土工布(B)、90 g/m^(2)土工布(C)、68 g/m^(2)土工布+砂滤料(D),以及无外包滤料(E)方案作为对照,通过室内渗透试验,田间春灌和秋浇排水过程的监测调查,综合分析不同外包滤料对暗管透水效果、保土和防淤堵性能的影响。结果表明:方案A、B和D的排水流量衰减率平均稳定在5.60%,方案C的衰减率仅次于方案E(15.094%),为11.15%。不同外包滤料达到稳定状态时的渗透系数在7.46×10^(-4)~9.46×10^(-4)cm/s之间,且GR≤3;各方案秋浇的土壤流失量较春灌时平均减少42%,方案D的土壤流失量衰减率仅为35%,低于其他方案(P<0.05),同时方案A~D的流失土壤d90分别为14.8、18.50、9.0和15.50μm与方案E(d90=23.33μm)相较,保土性能显著;B、C和D方案内的淤土量分别为12.54、17.64和7.00 g,方案D的淤土量显著低于其他单一铺设土工布的方案,可见方案D的防淤堵效果最优。综上,针对河套灌区下游土壤性质,推荐优先选择方案D(68 g/m^(2)土工布+砂滤料)作为灌区暗管外包滤料,该研究结果可为河套灌区下游选择适宜暗管外包滤料提供参考。

关键词：河套灌区暗管排水外包滤料透水效果防淤堵性

Nonlinear Extrapolation Estimates of π

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 91-108页

作者： wen-qing xu Sha-sha wang Da-chuan xu Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing100124China Department of Mathematics and Statistics California State UniversityLong BeachCalifornia90840USA Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang050043China

The classical Archimedean approximation of π uses the semiperimeter or area of regular polygons inscribed in or circumscribed about a unit circle in R~2 and it is well-known that by using linear combinations of these basic estimates,modern extrapolation techniques can greatly speed up the approximation ***,when n vertices are randomly selected on the circle,the semiperimeter and area of the corresponding random inscribed and circumscribing polygons are known to converge to π almost surely as n→∞,and by further applying extrapolation processes,faster convergence rates can also be achieved through similar linear combinations of the semiperimeter and area of these random *** this paper,we further develop nonlinear extrapolation methods for approximating π through certain nonlinear functions of the semiperimeter and area of such *** focus on two types of extrapolation estimates of the forms χ_n=S_n~αA_n~β and Y_n(p)=(αS_n~p+βA_n~p)~(1/p) where α+β=1,p≠0,and Sn and An respectively represents the semiperimeter and area of a random n-gon inscribed in the unit circle in R~2,and Xn may be viewed as the limit of Y_n(p) when p→*** deriving probabilistic asymptotic expansions with carefully controlled error estimates for Xn and Y_n(p),we show that the choice α=4/3,β=-1/3 minimizes the approximation error in both cases,and their distributions are also asymptotically normal.

关键词： Archimedean polygons random polygons approximations ofπ extrapolation processes asymptotic convergence

Performance analysis of cooperative diversity for two-way multi-relay system with channel estimation error

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The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 41-46页

作者： wang Si-ye xu wen-jun HE Zhi-qiang NIU Kai WU Wei-ling School of Information and Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this work, we consider an amplify-and-forward two-way multi-relay system for wireless communication and mvesngate me effect of channel estimation error on the error rate performance. With the derivation of effective signal-to-noise ratio at the transceiver and its probability density function, we can get approximate expression for average bit error rate. Simulation results are performed to verify the analytical results.

关键词： cooperative diversity two-way multi-relay Rayleigh fading channels amplify-and-forward relaying channel estimation error error probability