Results 91 to 100 of about 17,541,326 (249)
Shiyou jixie, 2015 为评估在役井架的承载能力，采用超声波测厚仪，在海上平台现场对服役8 a的HXJJ180井架杆件厚度进行了测量，据此建立了井架有限元模型,并按16种组合工况对井架进行了强度分析。由于井架各杆件不仅承受轴向力，而且也承受弯矩作用，故单元类型选择时考虑了结构尺寸和承受的载荷；将井架下底座视为刚体，约束连接处的所有自由度。分析结果表明，海洋修井机井架受环境腐蚀较为严重，有限元分析有助于掌握各杆件在给定工况下的应力及强度特性，采用超声波测量方法可获得精确的杆件厚度数据，保证有限元模型与实际井架相符 ...
doaj
FEBS Letters, EarlyView.CT10 regulator of kinase (CRK) and CRK‐Like (CRKL) are signaling adaptors driving cell adhesion, motility, differentiation, and proliferation. SH2‐domain containing (SH) proteins are enriched in YXXP motifs which when phosphorylated create preferred binding sites for CRK family SH2 domains.
Phoebe M. Cousens +8 more
wiley +1 more source
Shiyou jixie, 2015 鉴于国内外运用多相流数值模拟方法对水力喷射工具冲蚀研究有待深入的现状，基于多级水力喷射工具单级喷枪，采用颗粒碰撞的欧拉拉格朗日离散相模型，对水平井水力喷砂射孔过程进行流场分析及冲蚀速率计算。分析了单级喷枪上、下游喷嘴流场分布的不均匀性，以及这种不均匀性导致的工具内部各个喷嘴冲蚀速率的差异。分析结果表明，水力喷砂射孔过程中，水力喷射工具单级喷枪上、下游喷嘴流场呈现不均匀性，上游喷嘴单位时间通过的液体多于下游喷嘴，下游喷嘴的砂浓度高于上游3个喷嘴 ...
doaj
Reconstructing enzyme evolution by protein engineering
FEBS Letters, EarlyView.Natural enzyme evolution can be retraced by protein engineering methods such as directed evolution, rational design, and ancestral sequence reconstruction. These approaches reveal how enzymes emerged from ligand‐binding scaffolds, developed varying substrate preferences, formed oligomeric complexes, adapted to environmental changes, and evolved novel ...
Lukas Drexler +2 more
wiley +1 more source
Shiyou jixie, 2015 针对目前气井涡流携液机理和效率认识不清，现场工程设计与分析主要依据经验，影响应用效果等问题，运用AutoCAD和Fluent流体模拟软件，建立了涡流工具气液两相流场模型，分析了气液混合物通过涡流工具前后的流动轨迹、流型变化特征和携液效率变化规律。研究结果表明，涡流工具将气液两相雾流转换为螺旋环流，液体以液膜形式沿管壁螺旋向上流动，而气体在油管中心以更高的速度流动。这种流态能够降低流动过程中的压力损失24.3%，提高流体速度13.5%，减小持液率3.3%，减弱气液两相之间的滑脱，提高气体携液能力 ...
doaj
FEBS Letters, EarlyView.Cancer progression is regulated by the dynamic matrix code of the tumor microenvironment, which influences cellular behavior and disease development. Importantly, matrix remodeling in three‐dimensional cancer models more accurately reflects in vivo conditions compared to conventional two‐dimensional systems.
Sylvia Mangani +3 more
wiley +1 more source
Shiyou jixie, 2015 介绍了用重力加速度传感器测量重力工具面的原理，提出了一种提高精度和稳定性的小井斜重力工具面动态测量方法，搭建了基于石英加速度计的重力工具面动态测量系统，并针对现有自动垂直钻井系统在随钻状态下受到振动和冲击信号干扰测量精度下降和测量结果不稳定的问题，提出在常规硬件滤波的基础上，提高采样频率来反映信号原貌，加以多种数字信号处理方式以提高重力工具面动态测量精度。通过振动台的随机振动试验和井下实钻数据振动试验结果显示，测量精度和实时性均有提高。通过试验验证了该重力工具面测量方法和信号处理方式行之有效 ...
doaj
FEBS Letters, EarlyView.The process of internalization of the Shiga toxin A subunit via formation of a complex with the Shiga toxin B subunit, which specifically binds to the Gb3 receptor. The peptide is designed to act as a carrier of drugs into cancer cells. Here, we explored the potential of peptides derived from the catalytic A subunit of Shiga toxin (STxA) to be drug ...
Giulia Opassi +6 more
wiley +1 more source
Shiyou jixie, 2015 根据流体力学理论，以连续性方程和N-S方程为控制方程，利用计算流体力学理论对不同偏心度的赫巴流体环空流动进行系统的数值模拟，得到了偏心度的变化对于流场特性及摩阻压耗特性的影响规律，发现随偏心度不断增大，环空宽间隙处的流速剖面先不断增大，在达到临界最大流速剖面后又逐渐减小，其中先不断增大的规律依据已有研究且得到证实；运用涡黏理论对井壁、钻柱外壁及流体内部的应力-应变关系进行分析，揭示了达到临界流速剖面前、后流场内部不同的力学状态，以及随偏心度增大摩阻减小趋势不同的原因 ...
doaj
Investigating transcription factor dynamics in health and disease using FRAP
FEBS Letters, EarlyView.FRAP analysis of GFP‐tagged transcription factors reveals how molecular mobility and target engagement change in response to drug treatment. By combining live‐cell imaging, quantitative model fitting, and statistical analysis, this approach uncovers transcription factor dynamics linked to disease mechanisms, providing a powerful framework for ...
Kannan Govindaraj +3 more
wiley +1 more source