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逆流推力矢量喷管基本流动特征的数值研究

航空学报 2008年第4期29卷 769-775页

作者：杨建军汪明生南京航空航天大学能源与动力学院江苏南京210016

利用数值模拟的方法,通过对逆流方案中喷管气动性能的研究验证了逆流推力矢量方案的可行性。在非矢量状态下主喷管出口截面上的流量系数和推力系数分别达到99.2%和98.8%;矢量化状态下最大推力矢量角超过了20°,而推力系数与非矢量状态... 详细信息

利用数值模拟的方法,通过对逆流方案中喷管气动性能的研究验证了逆流推力矢量方案的可行性。在非矢量状态下主喷管出口截面上的流量系数和推力系数分别达到99.2%和98.8%;矢量化状态下最大推力矢量角超过了20°,而推力系数与非矢量状态下的比较下降不超过3.7%,且最大抽吸二次流量比仅为2.1%。此外,对该方案中一些基本的流动特征进行了分析,得到了抽吸二次流量比与推力矢量角的变化关系所揭示的流场结构,并对此进行了详细解释,同时揭示了逆流剪切层强烈的湍动特性和大涡结构的特点。

关键词：射流推力矢量喷管逆流剪切层流动控制抽吸二次流流动结构

Particle size dependence of the microsegregation and microstructure in the atomized Ni-based superalloy powders:Theoretical and experimental study

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Journal of Materials Science & Technology 2024年第4期171卷 54-65页

作者： Jikang Li mingsheng Yang Yunfei Cai Yuanyuan Zhang Qingshuai Feng Jiantao Liu Tong Liu Key Laboratory of Aerospace Materials and Performance(Ministry of Education)School of Materials Science and Engineering Beihang UniversityBeijing 100191China Central Iron and Steel Research Institute Beijing 100081China

The microstructure and microsegregation of atomized powder,which depend on their sizes,are of great importance to the mechanical properties of the consolidated bulk ***,it is necessary to reveal the relationship between particle size and powder *** effects of particle size on the so-lidification characterization of the atomized Ni-based superalloy powders were studied via finite element *** on the simulations,a model was developed to predict the microsegregation and mi-crostructure of atomized powders with different sizes and study the influence of thermal history on the powder attributes during the atomization *** radiation heat transfer and temperature gradi-ent within the rapid solidification alloy powders were taken into account in this *** validating the accuracy of the model,the predictions of the present model were compared with the microsegregation and microstructure of the specific size powder close to the screen mesh *** results showed that mi-crostructure depended primarily on the temperature gradient within the powder,while the solidification rate had a more significant effect on the *** model predicted microstructure features in agreement with the experiment,and for microsegregation,the deviations of prediction for most ele-ments were less than 10%.This work provides a new model to precisely predict the microsegregation and microstructure of the atomized alloy powders and sets a foundation to control the powder features for various engineering applications.

关键词： Particle size Solidification microstructure Microsegregation Numerical simulation

Study on the NaCl-CaCl_2 Binary System

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Rare Metals 1989年第1期9卷 9-13页

作者： Qiao Zhiyu Du Ailing Mo Wenjing Zhi Jinbiao wang mingsheng Zheng Chaogui Duan Shuzhen Dept.of Physical Chemistry,University of Science and Technology Beijing Former Beijing University of Iron and Steel Technology Dept.of Chemistry,Peking University. Univ of Science and Technology China

By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been *** is.a simple eutectic system with a solid solubility in the sodium chloride *** eutectic point is at 773K,49 mol% *** experimental results,especially those of the X-ray diffraction studies have showed that the incongruent compound 4NaCl-CaCl_2 does not exist in the NaCl-CaCl_2 system.

关键词： Study on the NaCl-CaCl2 Binary System NaCl

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泥水盾构穿越浅覆透水层施工关键技术研究

隧道建设 2016年第5期36卷 569-576页

作者：王明胜中铁隧道集团有限公司河南洛阳471000

针对我国关于繁华城区大直径泥水盾构施工关键技术研究不足的现状,以杭州环城北路地下通道工程大直径泥水盾构隧道施工为例,结合其工程施工难点,从浅埋地层大直径盾构始发、铁路桥变形预测、泥水分离系统及其适应性改造等方面,对工程中... 详细信息

针对我国关于繁华城区大直径泥水盾构施工关键技术研究不足的现状,以杭州环城北路地下通道工程大直径泥水盾构隧道施工为例,结合其工程施工难点,从浅埋地层大直径盾构始发、铁路桥变形预测、泥水分离系统及其适应性改造等方面,对工程中所遇到的难题进行了研究和针对性分析。研究结果表明:1)端头加固长度以大于盾构主机长度加1环管片的长度为宜;2)盾构下穿时铁路桥变形实测结果与理论预测结果相吻合,验证了理论预测的重要性;3)采取增加棒条和改造下层筛板等针对性措施,显著提高了泥水分离效果。

关键词：大直径泥水盾构繁华城区浅埋地层盾构始发变形预测泥水分离

南昌地铁泥水盾构穿越赣江浅覆盖透水层施工关键技术研究

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隧道建设 2015年第11期35卷 1222-1228页

作者：王明胜中铁隧道集团有限公司河南洛阳471009

结合南昌市轨道交通1号线一期工程秋水广场站—中山西路站区间隧道工程，对泥水盾构穿越赣江浅覆盖透水层时易出现的掌子面失稳、刀盘结泥饼、掘进姿态难控制等工程难题展开针对性研究。首先，从泥浆参数选择、切口水压计算、掘进控制技... 详细信息

结合南昌市轨道交通1号线一期工程秋水广场站—中山西路站区间隧道工程，对泥水盾构穿越赣江浅覆盖透水层时易出现的掌子面失稳、刀盘结泥饼、掘进姿态难控制等工程难题展开针对性研究。首先，从泥浆参数选择、切口水压计算、掘进控制技术3个方面对开挖面稳定控制技术进行分析；其次，在统计分析刀盘结泥饼现象及原因的基础上，提出严控泥浆指标等针对性的防控措施；最后，对 NFM－07、S367这2台泥水盾构掘进前100环（第165～265环）的掘进参数进行统计分析，进而得出了泥水盾构在浅覆盖透水层掘进时的盾构主要控制参数，以期为类似工程施工提供参考。

关键词：南昌地铁轨道交通过江隧道泥水盾构浅覆盖透水层开挖面稳定结泥饼

Highly responsive broadband Si-based MoS2 phototransistor on high-k dielectric

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Science China(Information Sciences) 2024年第6期67卷 180-189页

作者： Ali IMRAN Xin HE Jiwei LIU Qinghai ZHU Muhammad SULAMAN Fei XUE mingsheng XU Deren YANG College of Integrated Circuits State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University ZJU-Hangzhou Global Scientific and Technological Innovation Centre School of Materials Science and Engineering State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of Technology

The demand for photodetectors and image sensors has grown exponentially in the past decade in biomedical, security surveillance, robotics, automotive, quality control, image recognition, and military applications, due to their superior quality, broadband detection, lower noise, and economic viability. Here,we report a MoS2channel-based phototransistor over an HfO2/n-Si substrate isolated by an h BN layer. The high photoresponse is achieved through the integration of the photoconduction, photogating, and mobility enhancement process by utilizing excellent features of MoS2, HfO2/Si, and h BN. The capacitive coupling of the photogenerated carriers by high-k dielectric HfO2leads to modulation of MoS2Fermi level due to electrostatic doping. Furthermore, the MoS2also contributes to the photogeneration of carriers due to its semiconducting nature, leading to additional photocurrent. Ultimately, the combination of photogating,photoconduction, and swift carrier extraction with remarkable mobility of 11.65 cm2· V-1· s-1results in high responsivity, external quantum efficiency, and detectivity of 4.5 × 10～8A · W-1, 0.72 × 10～6, and 6.20× 1016Jones at 266 nm illumination, respectively. The device also demonstrates broadband photoresponse from 266–1000 nm wavelengths. The high responsivity distinguishes the potential of our device for the future of optoelectronics and broadband image sensing applications.

关键词： photogating photoconduction two-dimensional materials high $~k$ dielectric carrier scattering phototransistor

Cooperative Rate Splitting Transmit Design for Full-Duplex-Enabled Multiple Multicast Communication Systems

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工程与科学中的计算机建模(英文) 2024年第1期138卷 619-638页

作者： Siyi Duan mingsheng Wei Shidang Li Weiqiang Tan Bencheng Yu School of Physics and Electronic Engineering Jiangsu Normal UniversityXuzhou221116China School of Computer Science and Cyber Engineering Guangzhou UniversityGuangzhou510006China School of Information Engineering Xuzhou Vocational College of Industrial TechnologyXuzhou221140China

This paper examines the performance of Full-Duplex Cooperative Rate Splitting(FD-CRS)with Simultaneous Wireless Information and Power Transfer(SWIPT)support in Multiple Input Single Output(MISO)*** a Rate Splitting Multiple Access(RSMA)multicast system with two local users and one remote user,the common data stream contains the needs of all users,and all users can decode the common data ***,each user can receive some information that other users need,and local users with better channel conditions can use this information to further enhance the reception reliability and data rate of users with poor channel *** using Cell-Center-Users(CCUs)as a cooperative relay to assist the transmission of common data can improve the average system *** maximize the minimum achievable rate,we optimize the beamforming vector of Base Station(BS),the common streamsplitting vector,the cooperative distributed beamvector and the strong user transmission power under the power budget constraints of BS and relay devices and the service quality requirements constraints of *** the whole problem is not convex,we cannot solve it ***,we propose a low complexity algorithm based on Successive Convex Approximation(SCA)technology to find the optimal solution to the problemunder *** simulation results show that FD C-RSMA has better gain andmore powerful than FD C-NOMA,HD C-RSMA,RSMA and NOMA.

关键词： Full-duplex cooperative rate segmentation SWIPT RSMA power control

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垃圾秸秆焚烧炉应用现状及发展建议

现代农业科技 2024年第8期 88-91页

作者：罗朝阳罗吉李林王明昇何成奎高新随顺涛李光辉万先起蒋金巧谭杰达州职业技术学院四川达州635001 四川省农业机械科学研究院四川成都610066

随着城市化进程的加快和人们生产生活水平的提高,垃圾秸秆的处理与利用问题日益突出。垃圾秸秆焚烧炉具有可回收能源、环境友好等优点,开发和应用垃圾秸秆焚烧炉是解决垃圾秸秆问题的重要途径。基于此,本文介绍了垃圾秸秆焚烧炉的基本... 详细信息

随着城市化进程的加快和人们生产生活水平的提高,垃圾秸秆的处理与利用问题日益突出。垃圾秸秆焚烧炉具有可回收能源、环境友好等优点,开发和应用垃圾秸秆焚烧炉是解决垃圾秸秆问题的重要途径。基于此,本文介绍了垃圾秸秆焚烧炉的基本原理与分类,深入分析了垃圾秸秆焚烧炉的应用现状,并针对目前存在的技术滞后、废气处理难度大、投资周期长、国际合作欠缺等问题,提出了促进技术研发与创新、强化环境管理和减排、加强政府支持与政策引导、加强跨国合作与学习交流等发展建议,以期为促进垃圾秸秆资源化利用,降低生态环境污染,助力乡村振兴提供参考。

关键词：垃圾秸秆焚烧炉能源回收环境保护应用现状问题建议

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Combining red and blue-detuned optical potentials to form a Lamb-Dicke trap for a single neutral atom

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Combining red and blue-detuned optical potentials to form a ...