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Journal of Materials Science & Technology 2011年第9期27卷 856-860页

作者： B. Xu W.P. Tong c.z. Liu H. zhang L. zuo J.c. He Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern University Shenyang 110004 China Department of Materials Engineering Shenyang Institute of Aeronautical Engineering Shenyang 110034 China

The effect of magnetic field on the growth behavior of compound layer was examined at the interface between the solid cu and liquid AI during reactive diffusion. It was found that the thickness of compound layer was reduced by the high magnetic field. The growth activation energy in β, γ1 and ε2 layers under a high magnetic field was larger than those in non magnetic circumstances, the increment percentage being 4.8%, 13.3% and 5.5%, respectively.

关键词： Diffusion Activation energy High magnetic field Al cu

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

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Journal of Environmental Sciences 2007年第3期19卷 332-337页

作者： OJEKUNLE z.Olusheyi School of Environmental Science and Engineering Tianjin UniversityTianjin 300072China

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.

关键词： chlorobenzoate biodegradation Rhodococcus erythropolis psychrotrophic bacteria pathway

Soil Fertility,Microbial Biomass,and Microbial Functional Diversity Responses to Four Years Fertilization in an Apple Orchard in North china

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Horticultural Plant Journal 2020年第4期6卷 223-230页

作者： zhanling zhu Yan Bai Minglu Lv ge Tian Xin zhang Li Li Yuanmao Jiang Shunfeng ge State Key Laboratory of crop Biology College of Horticulture Science and EngineeringShandong Agricultural UniversityTai’anShandong 271018China National Agro-technical Extension and Service center Beijing 100125China

Soil microbial communities play an essential role in maintaining soil fertility and are considered as ecological indicators to evaluate soil *** the present study,we examined the influence of almost 4 years of fertilization[no fertilizer(cK),nitrogen alone(N),nitrogen,phosphorus and potassium chemical fertilizer(NPK),organicmanure(M),nitrogen plus organic manure(NM),and NPK plus organic manure(NPKM)]on soil fertility and the functional diversity of soil microbial communities in an apple *** to cK,fertilization increased soil organic carbon,total nitrogen,and available nutrients,but reduced soil pH in N and NPK *** highest microbial biomass carbon and nitrogen,most probable number of actinomycetes,bacteria,and fungi occurred in the NPKM *** average well color development(AWcD)values followed the order of NPKM>M>NPK and NM>cK and *** Shannon index in organic manure treatments were significantly higher than in control and in treatments without organic *** principal component analysis showed that manure treatment was significantly separated from other *** results indicated that organic manure applied alone or in combination with chemical fertilizers would increase soil fertility and functional diversity of soil microbial ***,applying balanced N,P,K fertilizer in combination with organic manure was found to be superior to the use of a single fertilizer in improving soil microbial community quality.

关键词： apple orchard fertilization soil fertility soil microbial community functional diversity

comparison Study of constitutive Models for Overconsolidated clays

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Acta Mechanica Solida Sinica 2020年第1期33卷 98-120页

作者： z.Wan Y.P.Yao z.W.Gao Research Institute of Base and Foundation China Academy of Building ResearchBeijing 100013China School of Transportation Science and Engineering Beihang UniversityBeijing 100091China School of Engineering University of GlasgowGlasgow G128QQUK

Widely distributed in natural deposits,the overconsolidated(Oc)clays have attracted extensive experimental investigations on their mechanical behaviors,especially in the 1960s and *** on these results,numerous constitutive models have also been *** models generally fall into two categories:one based on the classical plasticity theory and the other the bounding surface(BS)plasticity theory,with the latter being more popular and *** BS concept and the subloading surface(SS)concept are the two major BS plasticity *** features of these two concepts and the representative models based on them are introduced,*** unified hardening(UH)model for Oc clays is also based on the BS plasticity theory but distinguishes itself from other models by the integration of the reference yield surface,unified hardening parameter,potential failure stress ratio,arid transformed stress *** is made to the Hvorslev envelop employed in the UH model to improve its capability of describing the behaviors of clays with extremely high overconsolidation ratio in this *** comparison among the BS model,SS model,and UH model is *** shows that all these three models can characterize the fundamental behaviors of Oc clays,such as the stress dilatancy,strain softening and attainment of the critical *** UH model with the revised Hvorslev envelop has the fewest parameters which are identical to those of the modified cam-clay model.

关键词： clay Overconsolidation critical state Bounding surface Subloading surface Unified hardening model

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连接柱处理对圆盘泵性能及内部流场影响研究

水力发电学报 2024年第9期43卷 82-93页

作者：衡亚光罗西棚陈正甦江启峰张惟斌王川葛杰西华大学流体及动力机械教育部重点实验室成都610039 西华大学流体机械及工程四川省重点实验室成都610039 西华大学能源与动力工程学院成都610039 新界泵业(浙江)有限公司浙江温岭317525 扬州大学水利科学与工程学院江苏扬州225091

本文总结圆盘泵数值模拟方面的研究,对圆盘泵连接柱区域设置了两种不同的模型方案进行数值模拟。分析了不同流量工况下圆盘泵性能及叶轮内部流场变化,并对计算结果进行验证。结果表明:方案一连接柱两侧出现明显低速区域,方案二由于连接... 详细信息

本文总结圆盘泵数值模拟方面的研究,对圆盘泵连接柱区域设置了两种不同的模型方案进行数值模拟。分析了不同流量工况下圆盘泵性能及叶轮内部流场变化,并对计算结果进行验证。结果表明:方案一连接柱两侧出现明显低速区域,方案二由于连接柱周围水体旋转,因此区域速度值更大。两种方案均在叶片吸力面位置出现局部低压,因此圆盘泵内湍动能耗散主要出现在叶片及其吸力面侧,而在进、出口能量耗散较小。流体流过连接柱之后,方案二的圆周速度和绝对速度圆周分量均小于方案一,表明了圆盘泵实际运行过程中,连接柱对出口流动的阻碍作用产生的损失大于其带来的能量,导致方案二的扬程低于方案一。两种方案的计算结果与试验结果变化趋势一致,同时两种方案之间的差异较小,如果仅考虑快速计算圆盘泵性能,方案一在模型处理上更简单高效。如果要获得更全面准确的内部流动信息,方案二的内部流动情况更接近实际情况。

关键词：叶片式圆盘泵连接柱数值模拟内部流场水力性能

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PARAMETER IDENTIFIcATION IN HEMODYNAMIc MODEL OF cEREBRAL cIRcULATION

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Journal of Hydrodynamics 2001年第1期13卷 34-38页

作者： Yao, W. Ding, G.H. Liu, H. Wang, S.z. Lu, c.z. chen, S.H. Dep. of Mech. and Eng. Sci. Fudan Univ. Shanghai 200040 China

With a hemodynamic model of the Willis circulation, we developed a mathematical method to solve the inverse problem and obtained the values of indices in the model. compared with the clinical data from hospital, most ... 详细信息

关键词： Mathematical models

基于广泛靶向代谢组学揭示不同时期漆树生漆中代谢物变化规律

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植物学报 2024年第1期59卷 66-74页

作者：商慧颖翟云雁鬲晓敏刘帅王尚林周涛柏国清陕西省西安植物园(陕西省植物研究所) 陕西省植物资源保护与利用工程技术研究中心西安710061 西安交通大学药学院西安710061 中华全国供销合作总社西安生漆涂料研究所西安710061

生漆是一种重要的天然涂料,具有耐热、耐腐蚀和抗酸等优良特性,已广泛应用于各领域。揭示漆树(Toxicodendron vernicifluum)生长过程中生漆代谢物的变化规律是充分挖掘其应用潜力的关键。利用广泛靶向代谢组学技术,通过主成分分析、正... 详细信息

生漆是一种重要的天然涂料,具有耐热、耐腐蚀和抗酸等优良特性,已广泛应用于各领域。揭示漆树(Toxicodendron vernicifluum)生长过程中生漆代谢物的变化规律是充分挖掘其应用潜力的关键。利用广泛靶向代谢组学技术,通过主成分分析、正交偏最小二乘法判别分析和聚类热图分析等方法,对不同发育阶段(基于割漆时间)漆树的韧皮部汁液进行分析,探讨不同时期漆树生漆中代谢物的差异和变化规律。结果显示,在不同时期生漆中共鉴定出529种代谢物,包括黄酮类、酚酸类、生物碱、鞣质、糖和醇类及脂质等13类。多元统计分析表明,第Ⅱ、Ⅲ、Ⅳ和Ⅴ期生漆的代谢特征相似,且与第Ⅰ期存在较大差异。对不同发育时期生漆代谢物进行比较分析,鉴定出92种共同差异代谢物,其中黄酮类化合物主要积累于第I期生漆中,而氨基酸及其衍生物、糖和醇类在后期生漆中含量较高。研究结果为全面了解不同时期漆树生漆的代谢特征提供了依据,对漆树资源的开发利用具有重要意义。

关键词：漆树代谢组学生漆差异代谢物

Twisted Pair cable Fault Diagnosis via Random Forest Machine Learning

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computers, Materials & continua 2022年第6期71卷 5427-5440页

作者： N.B.Ghazali F.c.Seman K.Isa K.N.Ramli z.z.Abidin S.M.Mustam M.A.Haek A.N.z.Abidin A.Asrokin Faculty of Electrical and Electronic Engineering Universiti Tun Hussein Onn MalaysiaBatu PahatJohor TM Research&Development CyberjayaMalaysia

Applying the fault diagnosis techniques to twisted pair copper cable is beneficial to improve the stability and reliability of internet access in Digital Subscriber Line(DSL)Access Network *** network performance depends on the occurrence of cable fault along the copper ***,most of the telecommunication providers monitor the network performance degradation hence troubleshoot the present of the fault by using commercial test gear on-site,which may be resolved using data analytics and machine learning *** paper presents a fault diagnosis method for twisted pair cable fault detection based on knowledge-based and data-driven machine learning *** DSL Access Network is emulated in the laboratory to accommodate VDSL2 Technology with various types of cable fault along the cable distance between 100 m to 1200 ***,the line operation parameters and loop line testing parameters are collected and used to ***,the feature transformation,a knowledge-based method,is utilized to pre-process the fault ***,the random forests algorithms(RFs),a data-driven method,are adopted to train the fault diagnosis classifier and regression algorithm with the processed fault ***,the proposed fault diagnosis method is used to detect and locate the cable fault in the DSL Access Network *** results show that the cable fault detection has an accuracy of more than 97%,with less minimum absolute error in cable fault localization of less than 11%.The proposed algorithm may assist the telecommunication service provider to initiate automated cable faults identification and troubleshooting in the DSL Access Network System.

关键词： Twisted pairs random forest machine learning cable fault DSL

A FAMILY OF DIFFERENcE ScHEMES WITH FOURNEAR-cONSERVED QUANTITIES FOR THE KdV EQUATION

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Journal of computational Mathematics 1998年第2期16卷 129-140页

作者： Han, z Shen, LJ No Jiaotong Univ Dept Comp Sci & Technol Beijing 100044 Peoples R China Inst Appl Phys & computat Math Beijing 100088 Peoples R China

We construct and analyze a family of semi-discretized difference schemes with two parameters for the Korteweg-de Vries (KdV) equation. The scheme possesses the first four near-conserved quantities for periodic boundary conditions. The existence and the convergence of its global solution in Sobolev space L-infinity(0,T;H-3) are proved and the scheme is also stable about initial values. Furthermore, the scheme conserves exactly the first two conserved quantities in the special case.

关键词： convergence difference scheme KdV equation conserved quantity

航空铝合金激光焊接关键工艺参数与应力场关系

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兵工学报 2024年第5期45卷 1692-1702页

作者：李光祖王江涛谢利卢雅林张永康胡可军 c.M.cAScIOLA 江苏理工学院材料工程学院江苏常州213001 广东工业大学机械工程学院广东广州511400 School of Aeronautics and Mechanical Engineering Sapienza University of RomeSapienzaItaly

激光焊接工艺参数不仅影响铝合金结构件的残余应力,而且影响其服役性能,探究参数与应力场的关系对提高焊接结构件的质量具有重要的意义。采用圆锥热源模型对厚度为5 mm的7075-T7351铝合金板材进行激光焊接数值模拟,分析焊接速度和激光... 详细信息

激光焊接工艺参数不仅影响铝合金结构件的残余应力,而且影响其服役性能,探究参数与应力场的关系对提高焊接结构件的质量具有重要的意义。采用圆锥热源模型对厚度为5 mm的7075-T7351铝合金板材进行激光焊接数值模拟,分析焊接速度和激光能量两个关键参数对焊接残余应力场的影响规律,并借助实验验证模拟结果的准确性,揭示7075铝合金激光焊接工艺参数与应力场的关系。研究结果表明:残余应力会随着焊接速度的增加而不断增大,但当焊速超过一定值后焊核区应力不再增加,最大应力逐渐向两侧扩展;激光能量越大,导致残余应力降低且最大残余应力分布区域逐渐扩大;获得7075铝合金激光焊的最佳工艺窗口,焊接速度5~7 mm/s,激光焊接能量70~100 J/mm。所得研究成果在7075铝合金激光焊接工艺优化的周期缩短和成本降低方面具有一定的价值和意义。

关键词：铝合金激光焊接应力场焊接速度焊接能量