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Study on the Interface Bonding and Bending Fatigue Properties of Aluminum Alloy Foam Sandwich

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稀有金属材料与工程 2009年第A03期38卷 119-122页

作者： Zhang Min chen Changjun Chang qingming Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science ＆ Technology Wuhan 430081 China

Foam materials have many attractive properties because of their low-weight and cell structure. By sandwiches with an aluminum-foam core, it is possible to obtain higher structural stiffness and rigidity, maintain stability against buckling and additionally make use of the high energy dissipation capability of the bare foams. The most obvious and straightforward one is adhesive bonding of pre-fabricated aluminum foams and metal face sheets. A new manufacture processing is proposed for preparation of aluminum alloy foam sandwich, ie., Al-plate/mixed element powder/ Al-plate are sandwich rolled together by a large reduction in pass, which is then foamed in heating furnace to manufacture end-use product. Aluminum alloy foam sandwich is obtained in this experiment. The experimental results showed that the process of rolling interface belongs to mechanical bonding, whose mechanism is film theory. While interface bonding belong to metallurgy bonding in the process of foaming, Al atom interdiffused in the interface, and no new phase was generated in the foaming process of aluminum face sheet/powders precursor. Bending fatigue test results showed that the bonding force of the foamed sandwich interface is very high, in fatigue test fracture occurred in the whole foam aluminum sandwich panels and Al/foam core interface was not laminated.

关键词：泡沫材料复合材料泡沫塑料物理性能

Improvement in structure and superconductivity of YBa2Cu3O6＋δ ceramics superconductors by optimizing sintering processing

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Journal of Rare Earths 2017年第1期35卷 85-89页

作者： JIN Fei ZHANG Hui WANG Wenzhang LIU Xiang chen qingming Faculty of Materials Science and Engineering Kunming University of Science and Technology Kunming 650093 China

Polycrystalline YBa2Cu3O6＋δbulks were synthesized by sol-gel method. Sintering processing played a vital role in the evolution of phase structure and microstructure, and thus significantly influenced their superconducting properties. The influence of calcination temperature, sintering temperature, on the bulks structure, morphology and superconducting behaviors were investigated. The results showed that the oxygen content drastically increased with calcination temperature and sintering temperature. The SEM images revealed that the grains grew up monotonously with increase of calcination temperature. With increased calcination and sintering temperature, the resistivity was reduced gradually and the superconducting properties increased. Moreover, it was found that the optimal superconducting properties（with the highest superconducting transition temperature Tc^onset and the narrowest transition width ΔT） were obtained at calcination temperature of 900℃ and sintering temperature of 950 ℃.

关键词： YBa2Cu3O6+δ sol-gel method sintering processing superconducting property rare earths

A Space State Forecast Model for Dam Construction Equipments Based on Analysis Prediction Theory

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Wuhan University Journal of Natural Sciences 2007年第2期12卷 307-310页

作者： WU qingming chen Yongqiang ZHANG Zhiqiang School of Power and Mechanical Engineering Wuhan University Wuhan 430072 Hubei China

Anti-collision equipments system is developed to solve the collision problems of dam construction equipments, and in the system the determination of equipments＇ space state is important. A uniform moving equation of equipments is established based on the analysis prediction theory and the movements states of equipments. Method of least square was employed to deal with discrete data of equipments＇ space position. Fitting equation matched with the movement equation was presented to do data fitting, and a relevant algorithm was given. Applying the fitting equation, current and future space state of equipments can be accurately predicted. Finally, a case is given and results show that numerical values of data were steady and their precision was high. In LongTan dam construction of the equipments antiollision system, applying this method to forecast the equipments＇ space states and practical running of the system indicate that this method can improve the precision of position, obtain the better forecasting effect and increase the robustness of the system.

关键词： construction equipments analysis prediction anticollision system method of least square

A digitally generated ultrafine optical frequency comb for spectral measurements with 0.01-pm resolution and 0.7-μs response time

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Light(Science & Applications) 2015年第1期4卷 306-312页

作者： Yuan Bao Xingwen Yi Zhaohui Li qingming chen Jianping Li Xudong Fan Xuming Zhang Institute of Photonics Technology Jinan UniversityGuangzhou 510632China School of Communication and Information Engineering University of Electronic Science and TechnologyChengdu 610051China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China Biomedical Engineering Department University of MichiganAnn ArborMichigan 48109USA Department of Applied Physics Hong Kong Polytechnic UniversityHong Kong S.A.R.China

Optical spectral measurements are crucial for optical sensors and many other applications,but the prevailing methods,such as optical spectrum analysis and tunable laser spectroscopy,often have to make compromises among resolution,speed,and *** frequency combs are widely used for metrology of discrete atomic and molecular spectral ***,they are usually generated by optical methods and have large comb spacing,which limits the resolution for direct sampling of continuous *** overcome these problems,this paper presents an original method to digitally generate an ultrafine optical frequency comb(UFOFC)as the frequency ruler for spectral *** comb line provides one sampling point,and the full spectrum can be captured at the same time using coherent *** an experimental demonstration,we adopted the inverse fast Fourier transform to generate a UFOFC with a comb spacing of 1.46 MHz over a 10-GHz range and demonstrated its functions using a Mach–Zehnder refractive index *** UFOFC obtains a spectral resolution of 0.01 pm and response time of 0.7 μs;both represent 100-fold improvements over the state of the art and could be further enhanced by several orders of *** UFOFC presented here could facilitate new label-free sensor applications that require both high resolution and fast speed,such as measuring binding kinetics and single-molecule dynamics.

关键词： coherent detection digital signal process optical frequency combs optical sensors optical spectrometry

Van der Waals integration inch-scale 2D MoSe_(2) layers on Si for highly-sensitive broadband photodetection and imaging

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Nano Research 2023年第8期16卷 11422-11429页

作者： Yupiao Wu Shuo-En Wu Jinjin Hei Longhui Zeng Pei Lin Zhifeng Shi qingming chen Xinjian Li Xuechao Yu Di Wu School of Physics and Microelectronics and Key Laboratory of Material PhysicsZhengzhou UniversityZhengzhou 450052China Department of Electrical and Computer Engineering University of California San DiegoLa JollaCA 92093USA School of Microelectronics Science and Technology Sun Yat-Sen UniversityZhuhai 519082China Key Laboratory of Multifunctional Nanomaterials and Smart Systems Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China

As one of the most promising materials for two-dimensional transition metal chalcogenides(2D TMDs),molybdenum diselenide(MoSe_(2))has great potential in photodetectors due to its excellent properties like tunable bandgap,high carrier mobility,and excellent air *** 2D MoSe_(2)-based photodetectors have been reported to exhibit admired performance,the large-area 2D MoSe_(2)layers are difficult to be achieved via conventional synthesis methods,which severely impedes its future ***,we present the controllable growth of large-area 2D MoSe_(2)layers over 3.5-inch with excellent homogeneity by a simple post-selenization ***,a high-quality n-MoSe_(2)/p-Si van der Waals(vdW)heterojunction device is in-situ fabricated by directly growing 2D n-MoSe_(2)layers on the patterned p-Si substrate,which shows a self-driven broadband photoresponse ranging from ultraviolet to mid-wave infrared with an impressive responsivity of 720.5 mA·W^(−1),a high specific detectivity of 10^(13) Jones,and a fast response time to follow nanosecond pulsed optical *** addition,thanks to the inch-level 2D MoSe_(2)layers,a 4×4 integrated heterojunction device array is achieved,which has demonstrated good uniformity and satisfying imaging *** large-area 2D MoSe_(2)layer and its heterojunction device array have great promise for high-performance photodetection and imaging applications in integrated optoelectronic systems.

关键词： molybdenum diselenide large-area synthesis broadband photodetector integrated device array van der Waals(vdW)heterojunction

Improvement of water resistance of long afterglow SrAl_2O_4: Dy, Eu phosphor by coating with SiO_2 film

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Rare Metals 2002年第2期21卷 152-155页

作者： ZHANG Junying, chen qingming, LIN Yuanhua, and ZHANG ZhongtaiState Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University,Beijing 100084, China Department of Materials Science and Engineering Tsinghua University State Key Laboratory of New Ceramics and Fine Processing 北京 100084

The long afterglow SrAl_2O_4: Dy, Eu phosphor is liable tohydrolyze in water with deterioration of the lumin- escent ***_2O_4: Dy, Eu phosphors were therefore heated at 60-90 deg. C inTEOS sol to form a surface gel and then heat-treated at 400 deg. C toobtain SiO_2 coated phosphors. Observation by ?Transmission ElectronMicroscope (TE) and X- ray photoelectron spectroscopy (XPS) showsthat a thin silica film forms on the surface of the phosphors. Thecoating procedure can be illustrated by a four-step process and thetransparent silica film can suppress the hydrolysis process, so thatthe luminescent properties of the phosphors are unimpaired or evenbetter.

关键词： phosphors coating luminescent materials SrAl_2O_4

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磁约束放电CO激光模型的研究

中国激光 2000年第12期27卷 1067-1071页

作者：王涛陈清明华中科技大学激光技术国家重点实验室武汉430074

建立了磁约束放电 CO激光的模型。在该模型下分析、计算了 CO气体放电系统电子的能量分布函数 ;CO分子的电子碰撞激发速率 ,CO分子各振动态的布居数分布和对应的小信号激光增益系数。研究表明 ,由于磁场的加入 ,在对应 CO分子振动态电... 详细信息

建立了磁约束放电 CO激光的模型。在该模型下分析、计算了 CO气体放电系统电子的能量分布函数 ;CO分子的电子碰撞激发速率 ,CO分子各振动态的布居数分布和对应的小信号激光增益系数。研究表明 ,由于磁场的加入 ,在对应 CO分子振动态电子碰撞激发截面的能量范围内电子数有较大的增加。CO分子的电子碰撞激发速率提高。CO分子各振动能级均获得更大的布居数和激光小信号增益。

关键词： CO激光磁约束电子能量分布函数放电系统

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

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Neural Regeneration Research 2025年第4期20卷 1103-1123页

作者： Xiahong Tang Nan Zheng qingming Lin Yan You Zheng Gong Yangping Zhuang Jiali Wu Yu Wang Hanlin Huang Jun Ke Feng chen Shengli Clinical Medical College of Fujian Medical University Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Emergency Fujian Provincial HospitalFuzhouFujian ProvinceChina Fujian Provincial Key Laboratory of Emergency Medicine FuzhouFujian ProvinceChina The Second Department of Intensive Care Unit Fujian Provincial Hospital South BranchFuzhouFujian ProvinceChina

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological *** preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are *** this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB ***,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by *** results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these *** conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

关键词： bone marrow–derived mesenchymal stem cells cardiac arrest cardiac resuscitation hypoxic preconditioning liver isoform of phosphofructokinase mitochondria neuroinflammation oxidative stress pyroptosis reactive oxygen species

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磁约束铜蒸气放电中基态铜原子密度的测量

激光技术 1999年第6期23卷 368-371页

作者：李军陈清明武汉工业大学材料复合新技术国家重点实验室武汉430070 华中理工大学激光技术国家重点实验室武汉430074

利用吸收方法测量了磁约束铜蒸气放电中的基态铜原子密度，近室温的气体放电条件下得到铜原子密度达１０１４ｃｍ－３量级。结果表明，磁约束放电能够产生激光激励过程所需密度的铜原子蒸气，这为磁约束放电铜蒸气激光器的可行性研... 详细信息

利用吸收方法测量了磁约束铜蒸气放电中的基态铜原子密度，近室温的气体放电条件下得到铜原子密度达１０１４ｃｍ－３量级。结果表明，磁约束放电能够产生激光激励过程所需密度的铜原子蒸气，这为磁约束放电铜蒸气激光器的可行性研究提供了一个重要结论。

关键词：磁约束铜蒸气激光器基态原子密度密度测量