检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2021年第7期42卷 1029-1046页

作者： guangpu zhao Jiali ZHANG Zhiqiang WANG Yongjun JIAN College of Sciences Inner Mongolia University of TechnologyHohhot 010051China Transportation Institute Inner Mongolia UniversityHohhot 010021China School of Mathematical Science Inner Mongolia UniversityHohhot 010021China

In this work,the effects of externally applied axial pressure gradients and transverse magnetic fields on the electrokinetic energy conversion(EKEC)efficiency and the streaming potential of nanofluids through a microannulus are studied.The analytical solution for electro-magneto-hydro-dynamic(EMHD)flow is obtained under the condition of the Debye-Huuckel linearization.Especially,Green’s function method is used to obtain the analytical solutions of the velocity field.The result shows that the velocity distribution is characterized by the dimensionless frequency?,the Hartmann number Ha,the volume fraction of the nanoparticlesφ,the geometric radius ratio a,and the wallζpotential ratio b.Moreover,the effects of three kinds of periodic excitations are compared and discussed.The results also show that the periodic excitation of the square waveform is more effective in increasing the streaming potential and the EKEC efficiency.It is worth noting that adjusting the wallζpotential ratio and the geometric radius ratio can affect the streaming potential and the EKEC efficiency.

关键词： electrokinetic energy conversion(EKEC)efficiency nanofluid streaming potential magnetic field time-periodic excitation

Development of Constitutive Equation and Processing Maps for IN706 Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 198-204页

作者： Shuo Huang Lei Wang Xintong Lian Beijiang Zhang guangpu zhao Key lab for Anisotropy and Texture of Materials Northeastern University Department of High-temperature Materials Central Iron and Steel Research Institute

The hot deformation behavior of IN706 has been investigated by means of hot compression tests in the temperature range of 900-1150℃ and strain rate range of 0.001-1 s^-1. The constitutive equation was developed on the basis of experimental data. Power dissipation efficiency （η） and instability parameter （4） maps were evaluated using the principles of the dynamic material model. Furthermore, the EBSD microstructure analysis was performed for validation, revealing that η was closely associated with the mechanism of dynamic recrystallization （DRX）. Microstructure transition map was composed of contour plots of η, 4, and DRX. The DRX domain zones and instable zones were identified in the processing map and were classified based on η. In a view of microstructure refinement and workability improvement, the optimum processing should be selected in the temperature range of 970-1025 ~C and the strain rate range of 0.08-0.01 s^-1.

关键词： IN706 alloy Constitutive equation Power dissipation efficiency Flow instability Processing map

在线全文

学校读者我要写书评

暂无评论

工程建设中水文地质勘察技术的应用

大众科学 2024年第4期45卷 51-53页

作者：赵光朴河北省地质矿产勘查开发局第四水文工程地质大队(河北省地面沉降监测预警防治技术中心) 河北沧州061000

对工程建设中水文地质勘察技术应用进行分析和研究,然后阐述了工程建设中水文地质勘察技术的重要性,最后对工程建设中水文地质勘察技术应用进行了详细分析和探讨,希望能为工程建设中水文地质勘察技术的应用提供一些有价值的参考。

关键词：工程建设水文地质勘察技术具体应用

Nucleation mechanism of a nickel-base superalloy during dynamic recrystallization

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2011年第4期24卷 295-300页

作者： Shuai WANG Lei WANG Yang LIU GuohuaXU Beijiang ZHANG guangpu zhao Key Laboratory for Anisotropy and Texture of Materials Northeastern University Shenyang 110819China High Temperature Materials Research Institute Central Iron and Steel Research Institute Beijing100081 China

Hot compression test was carried out at 1000 ~C to investigate the dynamic recrys- tallization nucleation mechanism of a nickel-base superalloy. It was found that the bulging of original grain boundaries was inhibited by carbides and deformation twins at the boundaries. Recrystallized nuclei evolved from the subgrains of dislocation re- configuration along original grain boundaries, and the growth of the potential nuclei was carried out by the coalescence of subgrains. The necklace structure of recrys- tallized grains along original grain boundaries was attributed to the strain gradient from grain boundary to grain interior.

关键词： Dynamic recrystallization Electron backscattering diffraction（EBSD） Transmission electron microscopy （TEM） Superalloy

选区激光熔融Al-30Si合金的微观组织和性能

在线全文

学校读者我要写书评

暂无评论

材料研究学报 2024年第1期38卷 43-50页

作者：秦艳利赵光普张昊倪丁瑞肖伯律马宗义沈阳理工大学理学院沈阳110158 中国科学院金属研究所沈阳110016

用选区激光熔融技术(SLM)制备Al-30Si合金,研究了去应力退火后样品的显微组织、力学性能和热物理性能。结果表明:SLM成形的Al-30Si合金样品经300℃/6 h退火后其室温抗拉强度为254±3 MPa,比铸态加工的Al-30Si合金的抗拉强度提高53.5%,... 详细信息

用选区激光熔融技术(SLM)制备Al-30Si合金,研究了去应力退火后样品的显微组织、力学性能和热物理性能。结果表明:SLM成形的Al-30Si合金样品经300℃/6 h退火后其室温抗拉强度为254±3 MPa,比铸态加工的Al-30Si合金的抗拉强度提高53.5%,硬度为176.89±8.5HV、比刚度为35.18 m^(2)/s^(2)。SLM成形样品温度为-100℃~200℃时的热膨胀系数为13.8×10^(-6)/℃~16.3×10^(-6)/℃,平均热导率为70.52 W·m^(-1)·K^(-1)。快速冷却的特性能够细化SLM成形样品的初晶Si颗粒,使成形Al-30Si合金具有较好的综合性能,其高比刚度和较低的热膨胀系数有望使服役于特殊环境的光机结构件保持高度的尺寸稳定性。

关键词：金属材料选区激光熔融 Al-30Si合金微观组织物理性能

在线全文

学校读者我要写书评

暂无评论

一种纳秒级半导体激光器集成微模块

半导体技术 2024年第7期49卷 635-641页

作者：李军建赵永瑞师翔贾东东高业腾赵光璞贾凯烨河北新华北集成电路有限公司石家庄050200 河北省移动通信用射频集成电路重点实验室石家庄050200 中国电子科技集团公司第十三研究所石家庄050051

为提升半导体激光器在高重频下工作的稳定性,并满足模块高集成度的需求,研制了一款纳秒级半导体激光器集成微模块。该微模块包括半导体激光器芯片、装载激光器芯片的基板以及驱动电路。在基板侧面设计金属化过孔,将半导体激光器芯片的... 详细信息

为提升半导体激光器在高重频下工作的稳定性,并满足模块高集成度的需求,研制了一款纳秒级半导体激光器集成微模块。该微模块包括半导体激光器芯片、装载激光器芯片的基板以及驱动电路。在基板侧面设计金属化过孔,将半导体激光器芯片的电极从基板侧面引出,实现了激光的垂直发射;采用球栅阵列(BGA)封装GaN HEMT和GaN驱动器,优化电路布局和半导体激光器的回流路径,减小寄生电感,实现了1 ns的发光脉冲宽度,工作重频达到了1 MHz;同时,发光脉冲信号的前沿抖动度小于60 ps,脉冲宽度抖动度小于200 ps,表明其具有较高的稳定性。最后,采用高透明、耐高温的灌封胶对该微模块实现集成化封装,整体尺寸仅为6mm×5mm×2.6mm。

关键词：半导体激光器集成封装垂直发射 GaN驱动器窄脉冲

New insights in nano-copper chromite catalyzing ultrafine AP:Evaluation of dispersity and mixing uniformity

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 120-133页

作者： Yong Kou Peng Luo Lei Xiao Yanping Xin guangpu Zhang Yubing Hu Junqing Yang Hongxu Gao Fengqi zhao Wei Jiang Gazi Hao National Special Superfine Powder Engineering Research Center of China School of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing210094China Xi'an North Huian Chemical Industry Co.Ltd Xi'an710302China Xi'an Modern Chemistry Research Institute Xi'an710065China

Improving the application of nanomaterials has always been a research hotspot in the field of energetic materials(EMs)due to their obvious catalytic effect on the EMs,especially the uniformly dispersed nanomaterials.However,few studies have reported the dispersion of nanomaterials.In this study,the dispersity and mixing uniformity of nano-CuCr_(2)O_(4)was evaluated based on the difference of solid UV light absorption between the nano-catalytic materials and EMs.The nano-CuCr_(2)O_(4)/ultrafine AP composites with different dispersity of nano-CuCr_(2)O_(4)were prepared by manual grinding and mechanical grinding with different grinding strength and griding time.And then,the absorbance of different samples at 212 nm was obtained by solid UV testing due to the high repeatability of the absorbance at 210-214 nm for three parallel experiments,and the dispersity of different samples was calculated through the established difference equation.Furthermore,the samples were characterized by XRD,IR,SEM,EDS,DSC and TG-MS,which confirmed that different mixing methods did not change the structure of the samples(XRD and IR),and the mixing uniformity improved with the increase of grinding strength and grinding time(SEM and EDS).The scientificity and feasibility of the difference equation were further verified by DSC.The dispersity of nano-CuCr_(2)O_(4)exhibits a positive intrinsic relationship with its catalytic performance,and the uniformly dispersed nano-CuCr_(2)O_(4)significantly reduces the thermal decomposition temperature of ultrafine AP from 367.7 to 338.8℃.The TG-MS patterns show that the dispersed nano-CuCr_(2)O_(4)advanced the thermal decomposition process of ultrafine AP by about 700 s,especially in the high temperature decomposition stage,and the more concentrated energy release characteristic is beneficial to further enhance the energy performance of AP-based propellants.The above conclusions show that the evaluation method of dispersity based on solid UV curves could provide new ideas for the dispersity characterizati

关键词： Nano-CuCr_(2)O_(4) Ultrafine AP Dispersity UVeVis diffuse reflectance spectroscopy Thermal decomposition

锻态GH4742合金的热变形行为及组织性能演变

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2022年第11期51卷 4227-4236页

作者：秦鹤勇李振团赵光普张文云田强王冲钢铁研究总院高温材料研究所北京100081 北京钢研高纳科技股份有限公司北京100081 东北大学材料各向异性与织构教育部重点实验室辽宁沈阳110819

利用单道次等温压缩实验获得了锻态GH4742合金在变形温度为1020~1150℃、应变速率为0.001~1 s^(-1)、真应变为0.65时的真应力-应变曲线,构建了GH4742合金的热变形本构方程和热加工图。同时,采用SEM、EBSD等研究了热变形过程中微观亚结... 详细信息

利用单道次等温压缩实验获得了锻态GH4742合金在变形温度为1020~1150℃、应变速率为0.001~1 s^(-1)、真应变为0.65时的真应力-应变曲线,构建了GH4742合金的热变形本构方程和热加工图。同时,采用SEM、EBSD等研究了热变形过程中微观亚结构以及γ′相的演变规律,建立了变形工艺条件-组织形态差异-性能变化之间的关联性。结果表明:合金的组织性能演化机制与Z参数密切相关。1080℃低温变形时,应变速率由0.001 s^(-1)增加至1 s^(-1)后,lnZ值由74.6增加至81.6,热效应增强,基体动态再结晶比例增加,导致小角度晶界比例降低,但基体硬度由于动态再结晶组织发生细化而增加;1110℃高温变形时,随着应变速率增加,lnZ值由72.8增加至79.8,位错滑移和晶界迁移减缓,动态再结晶比例降低,造成小角度晶界比例增加,基体硬度由于加工硬化作用增加。GH4742合金不发生动态再结晶晶粒粗化的临界lnZ值为72。结合热加工图和变形组织分析得出锻态GH4742合金良好的加工区域为变形温度1110~1150℃、应变速率0.01~0.1 s^(-1)。

关键词： GH4742合金热变形行为动态再结晶组织硬度

固溶温度对GH4742合金力学性能及γ'相的影响

在线全文

学校读者我要写书评

暂无评论

材料研究学报 2023年第7期37卷 502-510页

作者：秦鹤勇李振团赵光普张文云张晓敏钢铁研究总院高温材料研究所北京100081 北京钢研高纳科技股份有限公司北京100081

采用EBSD、SEM等手段研究了固溶温度对GH4742合金的微观亚结构、力学性能和γ’相的影响。结果表明,固溶温度为1080℃~1120℃时,随着固溶温度的提高基体发生静态再结晶的比例提高,小角度晶界的比例由13.2%降低为3.2%;同时,晶粒显著粗化... 详细信息

采用EBSD、SEM等手段研究了固溶温度对GH4742合金的微观亚结构、力学性能和γ’相的影响。结果表明,固溶温度为1080℃~1120℃时,随着固溶温度的提高基体发生静态再结晶的比例提高,小角度晶界的比例由13.2%降低为3.2%;同时,晶粒显著粗化,平均晶粒尺寸由11.0μm增大到111.6μm,Σ3孪晶界的比例由13.2%提高到58.6%。随着固溶温度的提高,基体内一次γ’相的体积分数显著降低、尺寸增大,二次γ’相的体积分数和尺寸增加,三次γ’相的体积分数和尺寸变化较小。在不同固溶温度下γ’相强化增量的变化较小,晶粒粗化是导致其强度降低的主要因素。随着固溶温度的提高GH4742合金的室温强度显著降低,而高温强度提高和持久断裂时间显著增加。固溶温度为1100℃时,GH4742合金的室温和高温力学性能良好。

关键词：金属材料 GH4742合金固溶温度微观亚结构 γ'相力学性能

在线全文

学校读者我要写书评

暂无评论

多色矢量高斯-谢尔模型光束的焦移和焦开关

光子学报 2006年第1期35卷 142-145页

作者：赵光普吕百达四川大学激光物理与化学研究所

从交叉谱密度矩阵的传输公式出发,对多色矢量高斯-谢尔模型(GSM)光束的焦移和焦开关作了详细的研究·插入偏振片之前,多色矢量高斯-谢尔模型(GSM)光束通过硬边光阑透镜分离光学系统后,有焦移,但无焦开关;而插入偏振片之后,会出现焦开关... 详细信息

从交叉谱密度矩阵的传输公式出发,对多色矢量高斯-谢尔模型(GSM)光束的焦移和焦开关作了详细的研究·插入偏振片之前,多色矢量高斯-谢尔模型(GSM)光束通过硬边光阑透镜分离光学系统后,有焦移,但无焦开关;而插入偏振片之后,会出现焦开关·改变偏振片的旋转角度可以控制焦开关的特性·

关键词：现代光学焦移和焦开关多色矢量高斯-谢尔模型光束