Results 21 to 30 of about 560,483 (151)
Gaoya dianqi, 2023 阴极弧根为电子发射的主要区域，弧根的运动对空气直流电弧等离子体特性有重要意义。通过电极旋转驱动阴极弧根运动，实验观测得到电极旋转情况下空气直流电弧拉弧过程电极表面烧蚀情况、扭曲的弧柱形态，同时提取并对比了直线拉弧和旋转拉弧的电弧电压上升曲线。参照临界电流试验条件，建立小电流下平行电极间三维电弧仿真模型，探究在小电流情况下，自由燃烧态电弧的演变过程。仿真结果表明：阴极弧根运动使得发射后极间带电粒子空间分布变化，间隙放电通道改变，电弧的最大温度值降低；当电弧放电通道不稳定时，极间电弧电压出现波动 ...
付思, 陈文清, 曹云东
doaj
Microstructure Tailoring of Laser Powder Bed Fused Nb521 Alloy Toward Strength‐Ductility Synergy
Rare Metals, Volume 45, Issue 8, August 2026.ABSTRACT Niobium‐based refractory alloys are promising candidates for high‐temperature aerospace structures, yet their limited ambient‐temperature ductility and poor processability remain major barriers to broader implementation. Here, Nb521 alloy was fabricated by laser powder bed fusion (LPBF), and the effects of processing conditions and subsequent ...
Lele Qin +7 more
wiley +1 more source
Justice in coexistence: Pastoralism and large carnivores on the Qinghai‐Tibet Plateau
People and Nature, Volume 8, Issue 7, Page 2186-2199, July 2026.Abstract The conflict between livestock husbandry and large carnivore conservation presents significant challenges in grassland ecosystems worldwide. Achieving sustainable coexistence among herders, livestock and large carnivores requires reconciling diverse perspectives and interests through equitable, inclusive and fair processes that address both ...
Yufang Gao, Yue Yu
wiley +1 more source
Shuitu Baochi Xuebao, 2006 在一个较小的时空尺度上对典型喀斯特地区石漠化过程中的土壤质量演变特征及其退化过程进行了探讨。结果表明：由于植被破坏和耕地的开垦发生土壤颗粒粗化，向石漠化景观发展，土体结构破坏，容重增加0．12～0．60g／cm^3，总孔隙度降低12．0％～39．8％，持水性能变劣，养分也随之下降；〈0．05mm的粘粉粒流失，表层土壤有机质和全氮含量下降33．4％～84．6％和43．3％～85．2％。土壤质量的演变，既有系统本身的自然属性决定的内在原因，更重要的是人为的外部干扰体系的驱动；演变的过程既有渐变型，又有跃变型。
龙健, 李娟, 汪境仁, 李阳兵
doaj +2 more sources
Auto-focus technology and its application based on image processing [PDF]
, 2009 Auto-focusing technique is an important method to improve the precision,intelligentization,automatization for the indentation diameter measurement.The paper introduces an auto-focus method of indentation diameter measurement based on image processing ...
Chen, Xiaomei, Yang, Tao, Zuo, Yong
core +2 more sources
Kongjian kexue xuebao, 2023 小天体检测是小天体防御和预警的前提。针对小天体目标信噪比低、检测难的问题，提出了基于统计特征空间提取和支持向量机（SVM）的极暗弱小天体检测方法。区别于传统方法基于时间或空间上目标的能量和背景噪声能量的瞬时能量差别或是瞬时能量差别的累积，对目标进行检测。该方法不依赖目标能量大小，提取运动目标穿过背景时对稳定性产生的扰动来反演运动目标。将输入的图像序列转化为单像元时序信号，划分时序窗口提取统计特征，关联形成统计特征空间，利用更高维度的变化特性检测目标变化 ...
王 存远, 郑 伟, 李 明涛
doaj +1 more source
Rare Metals, Volume 45, Issue 5, May 2026.ABSTRACT Giga‐casting, a near‐net‐shape manufacturing process widely used in sectors such as new energy vehicles and aerospace, demands aluminum alloys with high integration, efficiency, and comprehensive performance. However, traditional die‐cast alloys still face two core bottlenecks: the strength–ductility trade‐off and high‐temperature ...
Zhanwei Su +3 more
wiley +1 more source
Spatially Downscaling of Future Food Demand for Policy Planning
World Food Policy, Volume 12, Issue 1, May 2026.ABSTRACT Understanding the subnational dynamics of food demand, while accounting for the evolution of the agrifood system at the global level, remains a challenge for designing food policy to ensure food security. To link global agrifood systems with subnational food policy planning, we downscale per capita food demand for 62 food commodities at the ...
Chun Song +3 more
wiley +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2019 闪电事件时空变化研究对于防灾减灾和资源利用具有重要意义。采用2 481 个站点的闪电日数数据诊断 1961—2016 年我国闪电事件的时空演变特征。结果表明：在时间上，1961—2016 年我国年均单站闪电日数整体呈减少趋势，西北西部和西藏地区年均单站闪电日数呈分段变化特征。全国、东北、北方、西北东部和东南地区年均单站闪电日数大致呈2~4 a 的周期变化。西北西部、西藏和西南地区分别呈2，4 和6 a，3 和8 a 与2~6 a 的显著周期变化。年均单站闪电日数突变集中发生在20 世纪80 年代末至90
KONGFeng(孔锋) +4 more
doaj +1 more source
Overreliance on Orthographic Similarity in L2‐Japanese Conceptual Processing by L1‐Chinese Learners
International Journal of Applied Linguistics, Volume 36, Issue 2, Page 1807-1820, May 2026.ABSTRACT Orthographic and phonological similarities between first (L1) and second (L2) languages can facilitate L2 processing. Particularly, L1‐Chinese learners of L2‐Japanese can benefit from the shared morphosyllabic Chinese characters (Japanese kanji/Chinese hanzi) because of their similar orthographies.
Xuehan Zhao, Kexin Xiong, Sachiko Kiyama
wiley +1 more source