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Toughening ultrastrong low-density steel by textured δ-ferrite lamellas

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Defence Technology（防务技术） 2024年第2期32卷 405-411页

作者： Bin Hu Guosen Zhu Guohui shen Zheng Wang qinghua Wen Xiao shen Haiwen Luo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingXue Yuan Rd.30Beijing 100083China Shougang Research Institute of Technology Yangzhuang Street 69Beijing 100043China Steel Institute RWTH Aachen UniversityIntzestraße 152072AachenGermany

By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and Si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.

关键词： Ultrastrong and light steel d-Ferrite lamellas Crack propagation Toughness

Review of fiber superluminescent pulse amplifications

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High Power Laser Science and Engineering 2016年第3期4卷 106-112页

作者： Haitao Zhang Xinglai shen He Hao qinghua Li Mali Gong Center for Photonics and Electronics State Key Laboratory of Precision Measurement and Instruments Department of Precision Instruments Tsinghua University

High coherence of the laser is indispensable light sources in modern long or short-distance imaging systems, because the high coherence leads to coherent artifacts such as speckle that corrupt image formation. To deliver low coherence pulses in fiber amplifiers, we utilize the superluminescent pulsed light with broad bandwidth, nonlongitudinal mode structure and chaotic mode phase as the seed source of the cascaded fiber amplifiers. The influence of fiber superluminescent pulse amplification(SPA) on the limitations of the performance is analyzed. A review of our research results for SPA in the fibers are present, including the nonlinear theories of this low coherent light sources, i.e., self-focusing(SF), stimulated Raman scattering(SRS) and self-phase modulation(SPM) effects, and the experiment results of the nanosecond pulses with peak power as high as 4.8 MW and pulse energy as much as 55 mJ. To improve the brightness of SPA light in the future work, we introduce our novel evaluation term and a more reasonable criterion, which is denoted by a new parameter of brightness factor for active large mode area fiber designs. A core-doped active large pitch fiber with a core diameter of 190 μm and a mode-field diameter of 180 μm is designed by this method. The designed fiber allows near diffracted limited beam quality operation, and it can achieve 100 mJ pulse energy and 540 W average power by analyzing the mode coupling effects induced by heat.

关键词： superluminescent pulse amplification fiber amplification incoherent nonlinear effects very large mode field

区域旅游业绿色创新发展网络优势匹配与组态提升路径——以山东半岛城市群为例

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生态学报 2025年第2期45卷 493-510页

作者：刘佳申明哲安珂珂闫颖王灵恩赵青华中国海洋大学管理学院青岛266100 曲阜师范大学地理与旅游学院日照276800 中国科学院地理科学与资源研究所北京100101

人与自然和谐共生背景下,绿色创新作为旅游业绿色化转型的重要引擎,是对旅游发展方式转变和生态环境问题改善的积极回应,直接关系到旅游业经济增长与资源环境的协调发展。频繁的要素流动推动城市间绿色创新联系增强,探究区域旅游业绿色... 详细信息

人与自然和谐共生背景下,绿色创新作为旅游业绿色化转型的重要引擎,是对旅游发展方式转变和生态环境问题改善的积极回应,直接关系到旅游业经济增长与资源环境的协调发展。频繁的要素流动推动城市间绿色创新联系增强,探究区域旅游业绿色创新网络优势匹配的路径有助于因地施策推进区域旅游业可持续发展。探索构建区域旅游业绿色创新发展分析框架,综合运用超效率SBM模型、社会网络分析法、哈肯模型和核密度估计等方法,选择山东半岛城市群为研究案例地,测度和分析其旅游业绿色创新效率及其网络优势度和二者协同特征,进一步基于非对称创新理论和模糊集定性比较分析法识别区域旅游业绿色创新发展网络优势匹配的组态路径。研究发现:旅游业绿色创新效率在空间上具有“沿海沿边”的集聚分布规律;旅游业绿色创新效率网络优势度“马太效应”显著,形成以济南、东营为主的点状格局;二者协同度区域差异明显,可分为高度协同型、中度协同型和低度协同型3大类;旅游业绿色创新效率、网络优势度及二者匹配的提升路径可归纳为政府支撑的外向型市场拓展模式、政府扶持的内源型动力驱动模式和内外部环境双元驱动下的动态优化调整模式等7种。

关键词：旅游业绿色创新效率网络优势度社会网络分析哈肯模型模糊集定性比较分析山东半岛城市群

水利枢纽工程实景三维模型单体化研究及网络服务发布

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水利技术监督 2023年第1期 64-67,136页

作者：叶文芳沈清华孙雨邓神宝王进科中水珠江规划勘测设计有限公司广东广州510610

无人机倾斜摄影是一种对水利枢纽有效感知及表达的技术手段。文章对水利场景的倾斜摄影三维实景模型单体化及网络化进行研究,通过对水利工程实景模型的精细化构建及动态单体化,实现了大藤峡水利枢纽精细场景的属性数据库构建和网络动态... 详细信息

无人机倾斜摄影是一种对水利枢纽有效感知及表达的技术手段。文章对水利场景的倾斜摄影三维实景模型单体化及网络化进行研究,通过对水利工程实景模型的精细化构建及动态单体化,实现了大藤峡水利枢纽精细场景的属性数据库构建和网络动态单体化部署,对后期智慧流域建设的实景三维模型应用提供了一定的技术参考。

关键词：倾斜摄影无人机实景三维模型大藤峡水利枢纽动态单体化

Stable one dimensional(1D)/three dimensional(3D)perovskite solar cell with an efficiency exceeding 23%

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InfoMat 2022年第5期4卷 187-195页

作者： qinghua Chen Kaimo Deng Ying shen Liang Li School of Physical Science and Technology Jiangsu Key Laboratory of Thin FilmsSoochow UniversitySuzhouP.R.China

The interface properties of organic–inorganic mixed halide perovskite solar cells play a significant role in their photovoltaic *** states at the interface can decrease the power conversion efficiency through defect-assisted charge recombination and degrade the long-term ***-dimensional perovskites exhibit excellent *** can be combined with three dimensional(3D)perovskites to utilize their advantages for fabrication of highperformance *** this study,we successfully construct a robust interface for perovskite films through mixed-dimensional *** the introduction of a one dimensional(1D)-structured capping layer on the 3D perovskite through post-treatment,the number of defect states in the perovskite film is significantly decreased,while the lifetime of the photocarriers is *** addition,the 1D capping layer can serve as a diffusion barrier to reduce the ion migration and protect the vulnerable 3D perovskite against *** solar cells based on stacked 1D/3D structures exhibit a power conversion efficiency of 23.3%and maintain 80%of the initial efficiency after storage for over 800 h under ambient conditions with a humidity of 50%.Their performances are superior to those of the 3D *** study provides a simple approach to simultaneously enhance the efficiency and stability of perovskite solar cells and may guide the development of other solar cells.

关键词： interface passivation ion migration perovskite solar cells stability

Laser melted oxide ceramics:Multiscale structural evolution with non-equilibrium features

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Journal of Materiomics 2019年第3期5卷 436-445页

作者： Lu Song Jing Ma qinghua Zhang Zhijian shen State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China Department of Materials and Environmental Chemistry Arrhenius LaboratoryStockholm UniversityStockholm10691Sweden

Compared with the versatility in metal industry,application of laser on oxide ceramics is quite limited due to the intrinsic features of ceramics and limited understanding in laser-ceramic interaction mechanism,especially for high-energy laser that causes melting of *** this research,a study into general behaviors of several oxide ceramics melted by laser under inert atmosphere is *** factors in determining state transformation,chemical reduction and phase structure are summarized,with further investigation into the evolution in microstructure at multiscale and the corresponding novelty and *** is found that laser melting does show great potential in introducing deep reduction,unique microstructure,and notable increase in structure complexity and total entropy,and those features could contribute to some unconventional functional performance with brand-new structure-property relationship.

关键词： Laser Oxide ceramic Heterogeneity Defects Non-equilibrium

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氮添加对木荷容器苗生长量的影响

防护林科技 2024年第4期 25-27页

作者：沈庆华李求洁林露花周红敏彭辉百山祖国家公园龙泉保护中心浙江龙泉323700 龙泉市林业局浙江龙泉323700 龙泉市林业科学研究院浙江龙泉323700

以2年生木荷为研究对象,设置4个不同氮添加水平(A1—0 g·株^(-1),A2—0.1449g·株^(-1),A3—0.2838 g·株^(-1),A4—0.4257 g·株^(-1)),研究不同氮添加量对木荷大规格容器苗生长量的影响。结果表明:(1)不同氮添加对木荷地径和苗高的影... 详细信息

以2年生木荷为研究对象,设置4个不同氮添加水平(A1—0 g·株^(-1),A2—0.1449g·株^(-1),A3—0.2838 g·株^(-1),A4—0.4257 g·株^(-1)),研究不同氮添加量对木荷大规格容器苗生长量的影响。结果表明:(1)不同氮添加对木荷地径和苗高的影响,均表现为先增加后减小,A2处理最大。苗高的最大值为113.69 cm,地径的最大值为10.91 mm。(2)叶长以A4处理最大(18.29 cm),叶总数以A3处理最大(120片)。叶宽以A1处理最大(4.46 cm)。(3)随着氮添加量的增加,木荷容器苗根、茎、叶干质量均表现为A3处理最大,A2处理最小,茎、叶的干质量在4个处理间无显著差异(P>0.05),而木荷容器苗根、茎、叶的含水率均表现为随着氮素增加先增加后减少的趋势。

关键词：氮添加木荷容器苗生长量

AN EFFICIENT METHOD FOR SOLVING THE MIXED DIRECT-INVERSE PROBLEM OF THE TRANSONIC ROTATIONAL FLOW IN PLANE CASCADES

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Acta Mechanica Sinica 1989年第4期5卷 323-331页

作者： Liu Qiusheng shen Mengyu Ren Yuxin qinghua University qinghua University Qinghua China

The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock capturing methods. The direct problem and the mixed direct-inverse prob- lem of the rotational flow in a transonic plane cascade at both design and off design conditions are solved, and the results show that the present method has rapid convergence rate and high accuracy even for the flow with moderately strong shocks. The calculations have been carried out on the DPS-8 computer, and for the direct problem, only 50-80 iterations are needed, and 50-80 seconds of CPU time are required.

关键词： transonic flow cascade flow the rotational flow turbomachinery the mixed direct-inverse problem.

Nuciferine relieves type 2 diabetes mellitus via enhancing GLUT4 expression and translocation

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Food Science and Human Wellness 2023年第6期12卷 2040-2051页

作者： Tongxi Zhou Guanjun Song Di Tian qinghua Liu Jinhua shen Xinzhou Yang Ping Zhao School of Pharmaceutical Sciences South-Central University for NationalitiesWuhan 430074China Institute for Medical Biology&Hubei Provincial Key Laboratory for Protection and Application of Special Plants in the Wuling Area of China College of Life SciencesSouth-Central University for NationalitiesWuhan 430074China

Nuciferine contained in lotus leaves have been confirmed to have the effect of ameliorating hyperlipemia and hyperglycemia.A laser scanning confocal microscope was used to track the translocation of glucose transporter 4(GLUT4)in L6 cells and the changes in intracellular Ca^(2+)levels in real time,and related protease inhibitors combined with western blotting were used to explore the mechanism of ***,KK-Ay mice,the spontaneous type 2 diabetic mice,were used to evaluate the in vivo activity of *** this study,the in vitro studies indicated that nuciferine-induced GLUT4 translocation was regulated by G protein-PLC-PKC and AMPK pathways and nuciferine-enhanced intracellular Ca^(2+)was mediated by G protein-PLC-IP3-IP3R pathway,the increase in intracellular Ca^(2+)caused by nuciferine was not directly related to GLUT4 translocation,but both promote glucose *** in vivo results suggested that nuciferine ameliorated weight gain induced by high-fat diet,abnormal lipid metabolism and the symptoms of insulin resistance in KK-Ay diabetic *** blot results suggested that nuciferine increased AMPK and PKC phosphorylation levels in skeletal muscle and liver,and enhanced GLUT4 expression in skeletal *** together,this research showed that nuciferine has the non-negligible potential in the treatment of type 2 diabetes mellitus.

关键词： Nuciferine Type 2 diabetes mellitus Glucose transporter 4(GLUT4)