Results 31 to 40 of about 495,929 (143)

预混火焰与均匀各向同性湍流畸变

open access: yes, 1988
本文首先引入表征化学反应层厚度的长度尺度新概念,得出一个新的湍流火焰传播速度公式。其次,导出火焰层厚度随释放热量与初始热焓比值τ变化的递增关系。此外,还提出一个新的速度-压力相关式,阐明了预混湍流火焰层内湍流能量增大的机制 ...
谢象春
core   +2 more sources

不同来流下超高层建筑流固耦合风效应特性研究

open access: yesZhendong Ceshi yu Zhenduan
为了研究在流固耦合效应下不同来流对超高层建筑风效应特性的影响,采用分离涡方法(detached eddy simulation,简称DES)对深圳平安金融大厦气弹模型进行全尺寸数值风洞模拟,利用湍流脉动生成(discretizing and synthesizing random flow field generation,简称 DSRFG)方法模拟大气边界层湍流和均匀来流,得到模型的风压和风致响应结果,并与风洞试验和现场实测数据进行对比。研究结果表明 ...
doaj   +1 more source

等高反坡阶对昆明市松华坝水源区坡耕地氮、磷流失的影响

open access: yesShuitu Baochi Xuebao, 2017
选取昆明市松华坝水源区典型小流域——迤者小流域为试验区,通过布设标准径流小区,在2009—2015年对坡耕地产流产沙及氮、磷流失情况进行长期的野外观测研究,从年际尺度上来探讨等高反坡阶对于坡耕地产流产沙及氮、磷等养分流失的影响。结果表明:等高反坡阶对于径流和泥沙的削减效果均较为明显,年平均减流率为50.64%,年平均减沙率74.99%,减沙率显著大于减流率;等高反坡阶对于径流和泥沙中氮、磷均有较为明显的削减效果,平均每年可以削减68.75%的氮流失和82.16%的磷流失 ...
王帅兵, 王克勤
doaj  

Functionalized Silica‐Constructed Self‐Supporting Composite Separator for Lithium Metal Batteries

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Lithium metal batteries (LMBs) are considered highly promising next‐generation energy storage systems owing to their exceptionally high theoretical specific capacity and ultralow electrochemical potential. Nevertheless, the practical deployment of LMBs is still severely restricted by the uncontrollable formation and propagation of lithium ...
Li Chen   +6 more
wiley   +1 more source

黄土坡面土壤侵蚀中溶质随径流迁移的水动力特性研究

open access: yesShuitu Baochi Xuebao, 2008
通过对比分析坡面水流的水动力参数与径流溶质迁移量间的关系,研究了不同地表状况下黄土坡面土壤溶质随径流迁移的水动力学特性,以求深入了解和认识坡面土壤侵蚀中溶质随径流迁移的本质机理。研究结果表明:不同坡面地表状况下,糙率系数和平均水深之比(n/h)与侵蚀过程中随径流迁移的溶质存在一定的关系,径流溶质Br-平均浓度、径流溶质Br-的平均流失率以及径流溶质Br-的相对流失量均随n/h的增加而减小。径流溶质Br-的平均流失率以及径流溶质Br-的相对流失量与水流水动力学参数n/h具有指数关系。
郭太龙, 王全九
doaj  

Nonequilibrium Precipitation Pathway Enabling Direct δ‐phase Formation and Enhanced Cryogenic Strength–Ductility in an Additively Manufactured Multi‐Principal‐Element Alloy

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Overcoming the strength–ductility trade‐off in face‐centered cubic (FCC) multi‐principal element alloys (MPEAs), particularly at cryogenic temperatures, remains a significant challenge. Here, a laser powder bed fusion (LPBF)–enabled direct aging strategy is employed to modify the precipitation behavior in a Ni53Fe20Cr23Nb4 (at%) alloy.
Xiaohui Qin   +8 more
wiley   +1 more source

Balancing d‐π/d‐π* Interactions: Valence‐Engineered Pd/TiO2 for Photocatalytic Acetylene Semi‐Hydrogenation

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Photocatalytic acetylene (C2H2) semihydrogenation is a green route for ethylene (C2H4) production, yet the activity–selectivity trade‐off caused by imbalanced adsorption/activation of reactants and products remains a core challenge. Herein, we realize precise regulation of Pd oxidation states (Pd0, Pdδ+, and Pd2+) on anatase TiO2 nanocubes via
Zhidan Wang   +7 more
wiley   +1 more source

彩色多普勒超声检测门静脉、脾静脉血流动力学在肝硬化食管胃底静脉曲张患者中的临床应用研究

open access: yesZhongguo shiyan zhenduanxue, 2023
目的 探讨彩色多普勒超声检测门静脉、脾静脉血流动力学在肝硬化食管胃底静脉曲张患者中的临床应用价值。方法 选取2018年1月-2021年12月于华北理工大学附属医院住院的肝硬化伴食管胃底静脉曲张患者88例为病例组。选择同期住院的肝硬化不伴有食管胃底静脉曲张患者102例为对照组。观察两组患者门静脉、脾静脉血流动力学变化情况。结果 病例组在总横断面表面积、胃左静脉直径、肠系膜上静脉直径高于对照组,在曲张静脉壁厚度低于对照组,差异均有统计学意义 ...
刘水澎, 张国顺
doaj  

Competitive Anion Coordination Modulates Anode Interfacial Chemistry for Wide‐Temperature Sodium Batteries

open access: yesRare Metals, Volume 45, Issue 10, October 2026.
ABSTRACT Sodium‐ion batteries (SIBs) offer a promising, cost‐effective alternative for large‐scale energy storage due to the abundance of sodium. However, their practical deployment is challenged by sluggish interfacial kinetics and unstable interphase formation, which severely limit performance across wide temperature ranges. Here, we demonstrate that
Mingxing Zhang   +10 more
wiley   +1 more source

非均匀布风对流化床埋管换热特性的影响

open access: yes, 2000
通过试验研究了埋管换热系数同换热区以及流动区流化速度之间的关系:换热系数变化的趋势及数值的大小与鼓泡床有明显不同,较大的流动区流化速度(6.0υ_{mf}~24.0υ_{mf}) 直接影响换热区埋管的换热系数,换热系数同流化速度之间较为平缓的关系便于利用埋管进行非均匀布风流化床中浓相床区温度的调整与控制。非均匀布风对流化床埋管换热特性有一定的影响,埋管的对流换热系数不仅是埋管所处换热区流化速度的函数,而且与相邻的流动区流化速度有一定关系。本文通过试验研究了埋管换热系数同换热区以及流动区流化速度之间的关系:
田文栋   +4 more
core   +2 more sources

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