Results 41 to 50 of about 248,377 (289)

Suppression of Stick-Slip Vibration of Drill String by Fractional-Order PID Control

Shiyou jixie, 2020
Stick-slip vibration of drill string is one of the important reasons leading to accelerated wear and premature damage of drilling equipment, reduced drilling safety and reduced drilling efficiency.
Zhang Qizhi, Xu Shuai
doaj  

Nrsn1–Smarcc1 Coupling Regulates Neural Stem Cell Differentiation and Chronic‐phase Recovery After Ischemic Stroke

Advanced Science, EarlyView.
In the post‐stroke brain, Foxa2 induces the transcriptional upregulation of Nrsn1 in NSCs. Nrsn1 functionally couples with Smarcc1, modulating its nuclear availability and protein abundance, thereby influencing Smarcc1‐associated regulatory programs linked to neuronal lineage commitment. Through this coupling, Nrsn1 promotes the differentiation of NSCs
Ruolin Zhang, Chang Liu, Yuneng Zhou, Kaichen Zhao, Muyang Li, Bingcheng Cai, Ying Wang, Zhiyuan Yuan, Zhaoxin Liu, Zilong Yuan, Yao Xiao, Peiyang Zhou, Ke Shui, Wendai Bao, Min Zhang, Jun Qin, Jun Chen, Xin Yang, Zhiqiang Dong   +18 more
wiley   +1 more source

Simulation of the Drill String Vibration Signal System

Shiyou jixie, 2015
To understand the signal transmission processes and rules as well as the structure and components of signals inside the drill string,through establishing signal transmission model,a drill string vibration simulation software has been developed based on ...
宋一晨, 吕苗荣, 陆健
doaj  

Sandwich‐Structured Aramid Composite Papers with Heterogeneous Dielectric Layers for Integrated Corona Resistance and Thermal Conductivity

Advanced Science, EarlyView.
A sandwich‐structured aramid composite paper was designed to integrate high corona resistance and thermal conductivity. The fluorinated graphene/aramid surface layers effectively dissipate space charges to suppress corona discharge. Meanwhile, the boron nitride nanotube/aramid core layer constructs continuous heat‐conduction pathways.
Jun‐Wen Ren, Jun‐Xue Chen, Ying‐Ying Tong, Zi Wang, Jia‐Cheng Zhang, Lin Zhang, Bo Zhang, Fan Zhang, Guo‐Long Wang, Jun‐Wei Zha, Shen‐Li Jia   +10 more
wiley   +1 more source

Development of Similarity Theory-based Horizontal Well Drill String Test Apparatus

Shiyou jixie, 2016
In order to conduct research on dynamic properties of drill string in the horizontal well,a horizontal well drill string test apparatus is developed based on parameter correspondence between test model and site prototype.The parameter correspondence is ...
Ren Fushen, Liu Jianhua, Li Yang, Wang Baojin   +3 more
doaj  

Predicting the Reactivity of Acyclic Silylenes and Germylenes in Hydrogen Activation Using Machine Learning

Advanced Science, EarlyView.
Statistical models for the prediction of the energy profile of H2 activation by silylenes and germylenes were developed. A simple model based on increments of the elements in α‐position enabled robust energy prediction, extrapolation to new structures, and transferability to new tetrylenes and substrates.
Michelle Kleinhaus, Henning Remm, Prasenjit Palui, Alexander Linke, Viktoria H. Gessner   +4 more
wiley   +1 more source

Investigation of kinetic energy dissipation characteristics of the drill string during rotary drilling in underground coal mines

Geomechanics and Geophysics for Geo-Energy and Geo-Resources
In underground coal mine rotary drilling, rock-breaking energy is transmitted from the drill string to the drill bit. Nonlinear vibrations of the drill string within the borehole result in kinetic energy dissipation.
Shuhan Shi, Qingfeng Wang, Wei Jiang, Peng Chen, Yang Liu, Jingping Yang, Kun Xu, Hang Chen   +7 more
doaj   +1 more source

Mechanical Modelling of Drill‐Strings [PDF]

PAMM, 2003
AbstractVibrations in long torsional strings result in spatio‐temporal dynamics. These vibrations disturb the accuracy of the drilling process and may cause damage due to fatigue. The high costs of drillings are the main motivation for the suppression of vibrations of the drill–string. In this paper a model for the drill string is proposed. In order to
E. Kreuzer, H. Struck
openaire   +1 more source

Research on a Model of Nonlinear Coupled-vibration of Directional Well Drill String [PDF]

, 2015
Drill string vibrations are inevitable movement patterns during drilling process, the drill string vibrations form including longitudinal, lateral and torsional are recognized by most scholars.
YAN, Tie, YU, Xiaowen, WANG, Yufen, ZHANG, Nan, LIU, Shanshan, BI, Xueliang   +5 more
core   +1 more source

Vine‐Inspired Soft Robotics: Materials, Actuations, and Emerging Applications

Advanced Science, EarlyView.
Vine‐inspired robots grow from the tip, enabling navigation through confined spaces with minimal disturbance. This Review summarizes material and actuation strategies for vine‐inspired growth, key functions including steering, retraction, attachment, branching, and variable stiffness, and emerging applications spanning medical intervention, confined ...
Jiahao Wu, Xingyun Liu, Fangzhou Wang, Huili Ren, Chaojun Zhang, Ziyu Ren, Zunqi Liu, Jing Li   +7 more
wiley   +1 more source