检索结果-南通市图书馆

NUMERICAl sOlUTION OF UNsTEADY DENsE PHAsE TRANsPORT OF PUlVERIZED COAl

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1991年第3期3卷 116-124页

作者： A.l.Ren Y.l.ma B.H.Zhong J.M.shi Department of Mechanics Zhejiang University Hangzhou 310027 P.R.China shanghai Power Equipment Research Institute Shanghai 200240 P.R.China

It presents the one-dimensional unsteady dense transport equation in the tube for MHD pulverized coal feed. The simplified frictional force term introduced by liu is used in the equation. The numerical solution has been got by using macCormack method. The results show that there exists optimal loading rate in which state velocity is not oscillation along a tube. It is well agreed with measurement, it also prevents a sediment in the tube.

关键词： Coal Handling Coal Pulverizers Computers Applications Fluid Mechanics mathematical Models

size and Interface Effects on Tensile strength of Polymers with Nano/Micro Particle Inclusions

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica solida sinica 2024年第5期37卷 812-822页

作者： R.Yuan X.ma l.H.liang Y.Wei College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing100029China Beijing Key lab of Health Monitoring and self-Recovery for High-End Mechanical Equipment Beijing100029China College of Engineering Peking UniversityBeijing100871China

Polymers with particle inclusions have wide applications,and the mechanical properties of polymer composites affect their reliability in *** strength of these composites is dependent on factors such as particle fraction,size,distribution,and interface interaction between the two phases,in addition to the properties of the polymers and *** size effect of particles and interface damage play an important role and thus draw considerable *** this paper,the size-and interface-dependent strength of polypropylene(PP)with nano/micro silica(siO_(2))particles of different fractions is studied through a combination of tensile experiments on a series of samples and corresponding three-dimensional(3D)finite element *** results indicate that PP with 2%siO_(2)nanoparticles of 50 nm exhibits relatively higher tensile strength,shedding light on the microstructure mechanism where smaller particle sizes lead to better interface ***,the particle size and interface coupling effect is analyzed based on the size-dependent elastic modulus model and the interface-cohesive *** simulation demonstrates the local interface damage evolution around a particle of the composites in *** findings are beneficial for designing polymer composites with nanoparticle inclusions.

关键词： Polymer-matrix composites Ceramic nanoparticles Mechanical properties size effect Interface damage

Ultra fast microwave-assisted leaching for the recovery of copper and tellurium from copper anode slime

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2015年第6期22卷 582-588页

作者： Zhi-yuan ma Hong-ying Yang song-tao Huang Yang lü liu Xiong school of materials and Metallurgy Northeastern University National Engineering laboratory of Bio-hydrometallurgy General Research Institute for Nonferrous Metals

The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology（RsM）. Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ± 0.16% and 98.68% ± 0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.

关键词： copper anode slime leaching microwave heating sulfuric acid response surface experiments

A singular linear Quadratic Time-Inconsistent Optimal Control Problem

在线全文

学校读者我要写书评

暂无评论

Journal of systems science & Complexity 2023年第3期36卷 1024-1052页

作者： ma Bowen school of mathematics Sichuan UniversityChengdu 610064China

Yong J [Acta math. Appl. sin. Engl. ser. 28(2012), 1–30] [math. Control Relat. Fields1(2011), 83–118] studied a standard linear quadratic time-inconsistent optimal control problem via a cooperative and non-cooperative approach, respectively. The authors extend his results to a singular case. To handle the singularity, the authors prove the solvability of a generalized Riccati equation,and introduce a notion of MP-convergence of matrix. It is shown that the authors can obtain a family of parameter equilibrium controls in both cases. Another interesting outcome is that a new type of parameter forward-backward Volterra integral equations is derived.

关键词： Equilibrium control -person differential game singular lQ problem time-inconsistency

Influence of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution

在线全文

学校读者我要写书评

暂无评论

Journal of materials science & Technology 2019年第7期35卷 1378-1387页

作者： l.M.Zhang s.D.Zhang A.l.ma A.J.Umoh H.X.Hu Y.G.Zheng B.J.Yang J.Q.Wang CAs Key laboratory of Nuclear materials and safety Assessment Institute of Metal ResearchChinese Academy of Sciences62 Wencui RoadShenyang 110016PR China school of materials science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016PR China shenyang National laboratory for materials science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016PR China

The effect of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution was investigated by cyclic polarization, Mott-schottky and X-ray photoelectron spectroscopy techniques. Results indicated that the open circuit potential of Al-Co-Ce amorphous alloys displayed a decreased tendency with the increase in Ce content, and the amorphous alloy with 4 at.% Ce presented both the lowest passive current density and donor density indicating the best corrosion resistance, while adding excess Ce led to the reduced corrosion resistance of Al-Co-Ce alloys, Furthermore, it was found that a low Ce content is beneficial to the formation of a more protective passive film on Al-Co-Ce amorphous alloys, and the corrosion inhibition reactions of Al-Co-Ce alloys in 0.6 M NaCl solution were changed with the increase in Ce content and the detailed reasons were discussed.

关键词： Amorphous materials Polarization Corrosion Photoelectron spectroscopies

Effect of alloying elements on mechanical properties in Cu-15%Cr in-situ composites

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第2期14卷 284-290页

作者： H.G.suzuki J.ma K.Mihara s.sakai s.sun Japan society for Promotion of science Department of Materials Science and EngineeringFurukawa Electric COFurukawa Electric CONational Institute for Materials Science 4-1-8 Hon-machi Kawaguchi332-0012 JapanDepartment of Materials Science and EngineeringTsinghua UniversityBeijing 100084 China Tsinghua UniversityBeijing 100084China LTDNikko 321-0014JapanLTDNikko 321-0014JapanTsukuba 305-0047Japan

The effects of alloying elements on the mechanical properties as well as electrical conductivity in Cu-15%Cr(mass fraction) in-situ composites were systematically studied and high strength and high electrical conductive Cu base in-situ composites have been developed. The best combination is the addition of 0.1% to 0.2% Zr, Ti, or sn in Cu-15%Cr in-situ composite, thermomechanical treatment to refine the microstructure and optimizing the precipitation of second phase. The strength is controlled by high density of dislocations in the Cu matrix, the lamellar spacing of the second phase, and the fine Cr precipitates. The aging treatment to reduce solute atoms has a beneficial effect on the increase of electrical conductivity. The addition of Zr, or Ti of about 0.15% to 0.2% promotes the precipitation of Cr particles.

关键词： CuCr合金铜合金内生复合材料机械性能合金化电导率

缺血性脑卒中铁死亡特征基因NFE2l2的鉴定与验证

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第7期29卷 1466-1474页

作者：王咪马书杰刘杨齐瑞上海中医药大学附属岳阳中西医结合医院康复医学科上海市200437 上海中医药大学上海市201203 上海市第二康复医院上海市200431

背景:铁死亡与缺血性脑卒中的发病密切相关,靶向铁死亡是一种治疗缺血性脑卒中有前景的方案,但具体调控靶点尚不明确。目的:通过生物信息学和机器学习方法筛选缺血性脑卒中铁死亡相关特征基因,并通过细胞实验进行验证,探讨铁死亡在缺血... 详细信息

背景:铁死亡与缺血性脑卒中的发病密切相关,靶向铁死亡是一种治疗缺血性脑卒中有前景的方案,但具体调控靶点尚不明确。目的:通过生物信息学和机器学习方法筛选缺血性脑卒中铁死亡相关特征基因,并通过细胞实验进行验证,探讨铁死亡在缺血性脑卒中的作用。方法:基于GEO数据库和FerrDb数据库选取符合条件的缺血性脑卒中相关数据集和铁死亡表达数据集,通过t检验筛选铁死亡相关差异基因。对铁死亡相关差异基因进行GO功能富集分析与KEGG信号通路富集分析。通过PPI网络分析和机器学习筛选缺血性脑卒中铁死亡的特征基因,利用ROC分析和GsEA分析探究特征基因的准确性和生物功能。然后进行细胞实验,将HT22细胞分为对照组与缺血性脑卒中组,对照组不作任何干预,缺血性脑卒中组加入0.1 mol/l的H_(2)O_(2)干预24 h诱导细胞氧化应激和铁死亡,通过实时荧光定量RT-PCR和Western Blot验证铁死亡的发生和特征基因表达。结果与结论:(1)共获取45个铁死亡相关差异基因,GO和KEGG富集分析发现差异基因与氧化应激、自噬、铁死亡、脂肪细胞因子信号通路和线粒体代谢密切相关。(2)通过PPI网络中的MCODE插件和cytoHubba插件与机器学习中的lAssO算法和sVM-RFE算法共鉴定出1个铁死亡特征基因核因子E2相关因子2(nuclear factor erythroid 2-related factor 2,NFE2l2)。(3)对NFE2l2进行ROC曲线分析,发现在训练集和验证集中构建的诊断预测模型具有良好的准确性与特异性;对NFE2l2进行GsEA分析,发现特征基因通过免疫、炎症反应、氨基酸代谢及神经因子调控等方面参与缺血性脑卒中发病机制的调控。(4)细胞实验的RT-PCR和Western Blot分析表明,与对照组对比,缺血性脑卒中组中的酰基辅酶A合成酶长链家族成员4 mRNA和蛋白表达水平显著增高(Pl2 mRNA和蛋白表达水平显著增高(Pl2可以为研究和治疗缺血性脑卒中提供一定的思路与方向。

关键词：缺血性脑卒中铁死亡生物信息学 HT22细胞机器学习特征基因细胞实验 NFE2l2 AsCl4 GPX4

在线全文

学校读者我要写书评

暂无评论

面向航拍路面裂缝检测的AC-YOlO

计算机工程与应用 2025年第01期61卷 153-164页

作者：白锋马庆禄赵敏重庆交通大学土木工程学院重庆交通大学交通运输学院重庆大学自动化学院

针对当前道路巡检智能化程度不足以及效率低等现状，为提高利用无人机道路巡检检测效率与检测精度，在YOlOv8s的基础上针对无人机航拍场景提出改进模型AC-YOlO，在主干网络引入动态大卷积核注意机制lsK-attention来扩展模型的感受野，... 详细信息

针对当前道路巡检智能化程度不足以及效率低等现状，为提高利用无人机道路巡检检测效率与检测精度，在YOlOv8s的基础上针对无人机航拍场景提出改进模型AC-YOlO，在主干网络引入动态大卷积核注意机制lsK-attention来扩展模型的感受野，提高对路面裂缝范围检测的准确性。在颈部结构设计多尺度特征融合策略，融入BiFPN网络，改善对细小裂缝的检测。替换损失函数为WIoUv3，优化梯度分配策略，使模型更加关注裂缝主体。在数据集UAV-PDD2023上进行实验验证，改进后AC-YOlO精准度达到0.895，较原模型提高0.128,maP50达到0.791，提高0.071,F1得分提高0.051，模型大小减小8.5%,FPs达到了129，提高4%。同时采用不同任务验证了模型泛化性能，实验结果证明AC-YOlO具有更强的检测性能，能有效应用于无人机视角下的路面裂缝检测。

关键词：道路巡检裂缝检测航拍裂缝增强感知特征融合

同方期刊数据库

A Photometric study of Two Contact Binaries: CRTs J025408.1+265957 and CRTs J012111.1+272933

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第9期22卷 223-238页

作者： shuo ma Jin-Zhong liu Yu Zhang Qingshun Hu Guo-liang lü Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of sciences Beijing 100049China school of Physical science and Technology Xinjiang UniversityUrumqi 830064China

We performed new photometric observations for two contact binaries(i.e., CRTs J025408.1+265957 and CRTs J012111.1+272933), which were observed by the 1.0 m telescope at Xingjiang Astronomical Observatory. From our light curves and several survey data, we derived several sets of photometric solutions. We found that CRTs J025408.1+265957 and CRTs J012111.1+272933 were A-and W-type W Uma, respectively. The results imply that the spot migrates or disappears in the two contact binaries, which were identified by chromospheric activity emissions(e.g., Hαemission) from lAMOsT spectra. From the O-C curves, the orbital periods of the two contact binaries may be increasing, which is interpreted by the mass transfer from the less massive component to the more massive one. With mass transferring, the two contact binaries may evolve from the contact configurations to semi-detached ones as predicted by the theory of thermal relaxation oscillation.

关键词： stars:binaries:eclipsing (stars:)binaries:spectroscopic stars:fundamental parameters stars:distances stars:individual(CRTs J025408.1+265957 CRTs J012111.1+272933)