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A NEURAL NETWORK FOR WELD PENETRATION CONTROL IN GAS TUNGSTEN ARC WELDING

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 27-33页

作者： C.S. Wu j. Q. gao Y.h. Zhao Institute of Materials joining Shandong University Jinan 250061 China

Realizing of weld penetration control in gas tungsten arc welding requires establishment of a model describing the relationship between the front-side geometrical parameters of weld pool and the back-side weld width with sufficient accuracy. A neural network model is developed to attain this aim. Welding experiments are conducted to obtain the training data set （including 973 groups of geometrical parameters of the weld pool and back-side weld width） and the verifying data set （108 groups）. Two data sets are used for training and verifying the neural network, respectively. The testing results show that the model has sufficient accuracy and can meet the requirements of weld penetration control.

关键词： neural network weld penetration control back-side weld width,gas tungsten arc welding

While neither universally applicable nor practical operationally, the biological species concept continues to offer a compelling framework for studying species and speciation

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National Science Review 2020年第8期7卷 1398-1400页

作者： Lexuan gao Loren h.Rieseberg CAS Center for Excellence in Molecular Plant Sciences Institute of Plant Physiology and Ecology Chinese Academy of Sciences Department of Botany and Biodiversity Research Centre University of British Columbia

Few topics in evolutionary biology have received as much scrutiny and debate as the nature of species and species concepts. This is partly because species are central to many fields of biology(but especially evolution, ecology, systematics, and conservation biology), and there does not appear to be a single concept that can satisfy the needs of these different disciplines [1].

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基于知识图谱技术的计算机网络链路漏洞检测研究

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现代电子技术 2025年第1期48卷 97-101页

作者：辛瑞雯高云山西大学山西太原030006 山西大同大学计算机与网络工程学院山西大同037009

计算机网络链路的漏洞信息具有类型复杂、来源广及数量庞大等特点,导致此类漏洞的威胁判断尤为困难。知识图谱技术具有数据整合及统一表示特性,可以统一结构化整合呈现复杂特点的漏洞信息,为此,文中提出基于知识图谱技术的计算机网络链... 详细信息

计算机网络链路的漏洞信息具有类型复杂、来源广及数量庞大等特点,导致此类漏洞的威胁判断尤为困难。知识图谱技术具有数据整合及统一表示特性,可以统一结构化整合呈现复杂特点的漏洞信息,为此,文中提出基于知识图谱技术的计算机网络链路漏洞检测方法。收集计算机网络链路的各种数据源漏洞信息,抽取其中的漏洞实体知识与关系知识,构建网络链路漏洞知识图谱。运用卷积神经网络模型学习该知识图谱中的漏洞知识,通过训练后的模型实现网络链路漏洞检测。结果显示,该方法可针对包含不同类型、数量链路漏洞的工况,实现漏洞知识图谱的构建,并且漏洞威胁检测精度始终保持在90%以上。因此,说明所研究检测方法的检测结果精准可靠,可为计算机网络链路数据安全传输提供保障。

关键词：知识图谱计算机网络链路漏洞漏洞实体知识关系知识知识抽取网络安全

Rheology Study of Suspension Formed by Different Nano-size Y-TZP

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journal of Materials Science & Technology 1997年第4期13卷 348-350页

作者： Sun, j gao, LA Guo, jK ChINESE ACAD SCI SHANGHAI INST CERAMSHANGHAI 200050PEOPLES R CHINA

The rheological properties of slurries formed by different nano-size Y-TZP have been studied. The viscosity is sensitive to solid loading especially for high solid content level. The dispersant Nh(4)PAA can improve the flowability efficiently. The smaller ceramic particles need to adsorb more dispersant to the flowability. Under the same solid content, the smaller the particles, the higher the viscosity of its slurry.

关键词： Rheology

Effects of welding parameters and post-heat treatment on mechanical properties of friction stir welded AA2195-T8 Al-Li alloy

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journal of Materials Science & Technology 2018年第1期34卷 219-227页

作者： j. Zhang X.S. Feng j.S. gao h. huang Z.Q. Ma L.j. Guo Technical Center Shanghai Aerospace Equipments Manufacturer Shanghai 200245. China

In this study, the effects of main welding parameters （rotation speed （ω） and welding speed （υ）） on the microstructure, micro-hardness distribution and tensile properties of friction stir welded （FSW） 2195-T8 Al-Li alloy were investigated. The effects of T6 post-treatments at different solution and aging conditions on the mechanical properties and microstructure characteristics of the FSW joints were also investigated. The results show that with increasing to and v, both strength and elongation of the joints increase first, and then decrease with further increase of ω and υ. All the joints under varied welding parameters show significant strength loss, and the strength reaches only 65% of the base metal, The effect of T6 post-heat treatment on the mechanical properties of the joints depends on the solution and aging conditions. Two heat treatment processes （480 ℃×0.5 h quenching＋ 180 ℃× 12 h, 520 ℃× 0.5 h quenching＋ 180 ℃×12h aging） are found to increase the joint strength. Furthermore, low temperature quenching （480℃） is more beneficial to the joint strength. The joint strength can reach 85% of the base metal. Whereas both low temperature aging （140 ℃× 56h） and stepped aging （ 100 ℃× 12 h ＋ 180 ℃× 3 h） processes decrease the joint strength. After heat treatment all the joints show decreased ductility due to the obvious grain coarsening in the nugget zone （NZ） and thermo-mechanically affected zone （TMAZ）.

关键词： 2195-T8 Al-Li alloy Friction stir welding Welding parameters Post-heat treatment

Critical Transitions of Microviscosity in Concentrated Polystyrene Solutions Revealed by Excimer Formation of Pyrenyl Probes

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Chinese Chemical Letters 1997年第6期8卷 543-546页

作者： gao, h Wang, GC he, BL NANKAI UNIV STATE KEY LAB FUNCT POLYMER MAT ADSORPT & SEPARATINST POLYMER CHEMTIANJIN 300071PEOPLES R CHINA

Excimer formation of pyrene and benzyl 4-(1-pyrenyl) butanoate was used to study the microviscosity of polystyrene/toluene solutions over the entire concentration range. Two critical concentrations (C(PS)similar to 0.32, 0.82g/ml) have been observed from the log-log plot of IB/IM vs C-PS. The results are explained in terms of the onset of cohesional interaction and the glass transition of the polymer chains, respectively.

关键词： Critical Transitions of Microviscosity in Concentrated Polystyrene Solutions Revealed by Excimer Formation of Pyrenyl Probes

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双编码端高分辨率遥感影像语义分割算法

计算机科学与探索 2025年第1期19卷 187-195页

作者：吴梦可高心丹东北林业大学计算机与控制工程学院哈尔滨150000

遥感影像具有多尺度对象、复杂背景、不均衡类别等特点。基于卷积神经网络(CNN)的语义分割算法难以捕捉到影像的全局特征,导致分割效果不佳。针对以上问题,利用Swin Transformer的全局特征提取能力,提出了双编码端高分辨率遥感影像语义... 详细信息

遥感影像具有多尺度对象、复杂背景、不均衡类别等特点。基于卷积神经网络(CNN)的语义分割算法难以捕捉到影像的全局特征,导致分割效果不佳。针对以上问题,利用Swin Transformer的全局特征提取能力,提出了双编码端高分辨率遥感影像语义分割算法DEGFNet。设计特征融合模块(FFB)将Swin Transformer捕获的全局特征引入编码端,应对多尺度对象带来的挑战。在Swin Transformer中设计空间交互模块(SIB),降低复杂背景样本带来的负面影响;在解码端引入全局-局部注意力模块(GLTB)和特征细化模块(FRB),来更好地利用编码端提取的信息,提高语义分割的精确性;采用交叉熵损失和Dice Loss组成的混合损失函数训练模型,减轻样本类别不均衡带来的消极影响。在Vaihingen数据集上,宏观平均F1值(mF1)、平均交并比(mIoU)和整体准确率(OA)指标分别达到91.9%、84.8%和92.4%;在LoveDA数据集上,mIoU指标达到55.0%,均展现出了更好的语义分割效果和良好的泛化性。

关键词：高分辨率遥感影像语义分割卷积神经网络 Swin Transformer

Impingement and mixing dynamics of micro-droplets on a solid surface

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Chinese journal of Chemical Engineering 2022年第12期52卷 66-77页

作者： Guina Yi Ziqi Cai Zhengming gao j.j.Derksen Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Chemical Resource Engineering School of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China School of Engineering University of AberdeenAberdeen AB243UEUK

The hydrodynamics and mixing during the nonaxisymmetry impingement of a micro-droplet and a sessile droplet of the same fluid are investigated by many-body dissipative particle dynamics(MDPD) *** this work,the range of the impingement angle(θ_(i)) between the impinging droplet and the sessile droplet is 0°-60° and the contact angle is set as 45° or 124°.The droplets impingement and mixing behavior is analyzed based on the droplet internal flow field,the concentration distribution and the time scale of the decay of the kinetic energy of the impinging *** dimensionless total mixing time(τ_(m)) is calculated by a modified mixing *** the Weber number(We) ranging from 5.65 to22.7 and the Ohnesorge number(Oh) ranging from 0.136 to 0.214,we find rm hardly changes with We and ***,θ_(i)and surface wettability are found to have a significant effect on τ_(m).We find that θ_(i)has no clear effect on τ_(m)on a hydrophobic surface,while on the hydrophilic surface,τ_(m)increase with the θ_(i).Thus,reducing the impinging angle is a valid method to shorten the τ_(m).

关键词： Droplets impingement Mixing behavior Mixing time Concentration distribution Many-body dissipative particle dynamics

A STUDY OF ThE ONSET OF KINK BAND

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Acta Mechanica Solida Sinica 1995年第3期8卷 189-201页

作者： gao, j LIN, XL ShANDONG POLYTECh UNIV JINANPEOPLES R CHINA

This paper suggests the asymmetric-plastic theory of crystalline solids concerning the plastic rotation of crystal. The deformation of crystalline solids undergoes three microprocesses, lattice distortion, slip over active crystallographic planes and the rotation- of the crystal. In the asymmetric-plastic theory of crystal suggested, the corotational rates of symmetric Cauchy stress and moment stress correspond to the rates of elastic strain and the gradient of the rotational rate of the crystal respectively. The Schmid yield condition and Prager's consistency condition incorporating antisymmetric stress are formulated. Then the asymmetric-plastic model of crystalline solids is applied for the investigation of the onset of kink band by a standard stability analysis. The orientation of the kink band is perpendicular to the primary slip system. The width of the kink band is the function of the ''characteristic length'' of the microstructure of metal materials.

关键词： KINK BAND PLASTIC ROTATION OF CRYSTAL