Results 61 to 70 of about 25,946 (168)

Research On Several Design Problem In A Super-High-RiseFrame – Corewall Building [PDF]

open access: yes, 2014
随着我国经济和房地产业的持续蓬勃发展,超高层建筑在各大城市中越来越多。随着建筑物高度的不断上升,结构种类也越来越复杂。由于超限高层的复杂性,不论从结构整体,还是结构构件上,超限高层结构的设计难度远大于比一般高层结构,在设计过程中有许多特殊的问题需要处理。如何解决在超限高层结构设计过程中遇到的特殊问题是结构工程师的首要任务。 本文以福建省龙岩市一个超限高层框架—核心筒结构为对象,在对该工程进行结构设计分析时,主要解决了以下三个问题: (1)根据业主的要求做了初步结构设计后 ...
陈涛
core  

Pyrolysis‐Engineered Fe/Mn‐ZIF Catalysts: Balancing Activity, Selectivity, and Stability for the Oxygen Reduction Reaction

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Metal oxide‐based catalysts for oxygen reduction reaction (ORR) have drawn great attention in recent years. However, it remains technically challenging for the precise regulation of the overall performance due to the trade‐off effect among the activity, selectivity, and stability of electrocatalysts. Herein, a balancing strategy to control the
Haoran Ma   +7 more
wiley   +1 more source

Free Vibration and Dynamic Analysis of Beams and Plates Using Hermite Reproducing Kernel Meshfree Method [PDF]

open access: yes, 2010
结构的自振频率反映了其振动特性,对于结构动力分析设计至关重要。本文基于Hermite再生核无网格法和稳定子域积分方法对薄梁板等结构进行自由振动分析。Hermite再生核无网格法是在多项式再生条件的理论框架下,同时将广义节点挠度和节点转角作为节点未知量来建立梁板挠度的无网格近似,进而与伽辽金法结合形成的无网格方法。本文将稳定子域积分法引入到无网格离散方程的积分中,该方法能准确满足积分约束条件,同时避免计算形函数高阶导数。分析表明,与仅将节点挠度参数作为未知量的传统再生核无网格近似相比 ...
林振庭
core  

Comparative Evaluation of Chemical and Physical Expansive Agents in Cemented Paste Backfill: Expansion Behavior, Mechanical Response, and Microstructural Mechanisms

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT This study presents an assessment of four representative expansive additives—calcium sulphoaluminate–calcium oxide, magnesium oxide, sodium lauryl sulfate, and sodium abietate—and their effects on the expansion behavior, mechanical development, and microstructural characteristics of cemented paste backfill (CPB).
Lijie Guo   +5 more
wiley   +1 more source

The Research of Wind-induced Control based on the energy balance principle [PDF]

open access: yes, 2013
随着建筑功能的多样化,以及新材料、新结构与新体系的迅猛发展与应用,高层建筑的楼层数逐渐增多,高度也逐渐增高,结构也变得越来越柔,这给我们的结构设计带来了新的要求和挑战,结构的抗风设计也因此变的更加重要。传统的抗风设计方法已不能很好的满足设计的要求,即使满足了要求,也是不经济的。有效、可靠、安全、经济的方法是采用结构的风振控制技术,即通过在结构中设置减震装置来减小结构的动力响应。本文在以往研究的基础上,基于能量的平衡原理,分别对一维和三维建筑结构进行风振控制研究,主要完成了以下工作: 1 ...
傅建芳
core  

Elevation, soil pH and calcium availability shape regional and local scale spatial patterns of PhoD gene abundance in tropical and subtropical forests

open access: yesFunctional Ecology, Volume 40, Issue 4, Page 983-1000, April 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Organic phosphorus mineralization is a critical process in the phosphorus cycle, governing phosphorus bioavailability for plants. The PhoD gene, which encodes the key enzyme alkaline phosphatase, serves as a valuable biomarker for this process.
Sandhya Mishra   +3 more
wiley   +1 more source

埋设管道竖向抬升时的土体抗力研究

open access: yesShiyou jixie, 2014
利用有限元软件ABAQUS来建模分析海底埋设管道在疏松、中等密度和致密砂土中不同埋深比下,管道竖向抬升时土抗力随位移的变化。分析结果表明,砂土的竖向土抗力随埋深比增加而增大,竖向土抗力达峰值时管道的竖向抬升位移也随之增大,砂土越密实最大竖向土抗力越大;当埋深比为2、3、4时,土体表面有明显的隆起现象;达到最大竖向土抗力时管道的竖向位移随着埋深增加而增大。分析结果与试验结果和理论结果相符,验证了有限元分析计算的可行性。最后指出,研究管道隆起屈曲过程中竖向土抗力的发挥过程和变化规律具有实际的工程意义。
谭双妮   +6 more
doaj  

Multi‐barcoding‐based species identification using a hierarchical attention network with staged curriculum learning

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 4, Page 1143-1160, April 2026.
Abstract DNA barcode‐based species identification has become pivotal in biodiversity research. Current barcoding‐based deep learning methods have advantages in species identification but exhibit significant limitations. By using COI barcoding alone, previous studies were unable to fully capture species identification features. Prior methods showed that
Bin Ye   +4 more
wiley   +1 more source

基于时域有限元法的电缆终端电场分析

open access: yesGaoya dianqi, 2010
基于后退欧拉法和变分原理推导了非线性的时域有限元电场计算方程。利用时域有限元方法分析了含不同应力控制管时的电缆终端电场分布。分析结果表明,采用由电容性和非线性电阻性材料复合绝缘结构的应力控制管时,电缆终端的电场分布最为均匀。
宫瑞磊   +4 more
doaj  

750 kV断路器击穿故障的过电压及物理场仿真分析

open access: yesGaoya dianqi, 2022
滤波器场SF6断路器需要根据系统运行工况的变化和对无功及滤波的需求随时开断和关合,750 kV滤波器场断路器相对其他电压等级运行工况更加苛刻,故障率高于常规罐式断路器。文中从投切过程波形分析、现场检查、暂态过程仿真对一起750 kV滤波器场断路器内部间隙击穿故障进行分析,给出了故障路径及原因。解体验证了间隙击穿分析正确性,并进一步开展电镜检测分析、异物动态运动轨迹仿真分析、异物附着屏蔽罩表面时电场强度仿真,确定了异物引发间隙击穿的根源,为加强滤波器场断路器异物管控及分析投切过程中异物引发内部击穿提供帮助。
马飞越   +5 more
doaj  

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