水平井卡钻事故的爆炸处理方法分析

在水平井钻进过程中,由于钻井液和地层等原因,不可避免的出现井内卡钻事故。有效的解卡不仅为钻井公司节约了大量成本,也为及时化解卡钻风险提供了保证。文章系统分析了水平井钻具松扣、切割施工中的难点。当经过泡油、震击还不能够解卡时,爆炸处理方法便能有效地解决此类卡钻问题,该项技术在大牛地气田水平井中也得到了很好的应用。     

琼东南盆地深水区地震资料品质影响因素探析

针对南海北部琼东南盆地深水区地震资料品质较差的问题,从深水区地质条件入手,结合海上地震资料采集试验及实践,综合分析了深水区现有地震资料品质与研究区带地质特征、采集参数及处理流程的关系,并提出了提高深水区地震资料品质的技术对策。     

瓦锡兰RT-flex主机校中与安装的技术要领

船舶主机是船舶动力装置中的重要组成部分,主机安装质量和轴系校中的好坏直接关系到动力装置的正常运行和船舶的航行性能。介绍了瓦锡兰RT-flex主机校中与安装工艺,并进一步分析了安装和校中的各项技术要领,可对主机的实船安装和制定瓦锡兰RT-flex主机安装和校中的工艺标准起到指导作用。     

Electroencephalogram and electrocardiograph assessment of mental fatigue in a driving simulator

Mental fatigue is a contributing factor to some serious transportation crashes. In this study, we measured mental fatigue in drivers using electroencephalogram (EEG) and electrocardiograph (ECG). Together, thirteen healthy subjects performed a continuous simulated driving task for 90 min with simultaneous ECG and multi-channel EEG recording of each subject. Several important physiological parameters were investigated using preprocessed ECG and EEG signals. The results show that the EEG alpha and beta, the relative power, the amplitude of P300 wave of event-related potential (ERP), the approximated entropy of the ECG, and the lower and upper bands of power of heart rate variability (HRV) are significantly different before and after finishing the driving task (p < 0.05). These metrics are possible indices for measuring simulated driving mental fatigue.     

搅拌摩擦焊接头形成过程分析

基于搅拌摩擦焊三维模型的切面分析方法,建立了焊接过程中接头切面的演变行为,将搅拌摩擦焊接头形成过程分为挤出阶段、迁移阶段、回填阶段和轴肩作用阶段四个阶段,对搅拌针作用下材料迁移过程进行了分析,指出挤出阶段将原始对接面及其表面氧化物迁移到后退侧,迁移阶段实现洋葱环层状组织的形成,并实现氧化物的碎化、弥散,回填阶段完成洋葱环形貌的最终成形.结果表明,采用切面分析法建立的接头形成过程四阶段能够较好地解释搅拌摩擦焊接头形成机制以及"S线"等缺陷的产生原因.     

Synthesis and characterization of carbon hollow microspheres

A facile approach was developed for synthesis of carbon hollow microspheres (CHM) via carbonization of the hollow polymer microspheres prepared from polymerization in the presence of l-lysine acted as in situ template. The physical and chemical structures of the samples were investigated by X-ray powder diffraction, Raman spectrum, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM and TEM images show that the products consist of a large scale of monodisperse CHM with a size of about 1.1–1.3 μm. Furthermore, the resulting CHMs possess a surface area of 559 m² g⁻¹ and a pore volume of 0.27 cm³ g⁻¹. The morphology and the size of the as-obtained samples can be controlled by the polymerization temperature, polymerization time, and the dosage of l-lysine. Moreover, a possible formation mechanism of the CHM has been put forward according to the experimental data available.     

SIFT keypoints detection based on FPGA

为了在现场可编程门阵列(FPGA)中用硬件电路实现尺度不变特征转换(SIFT)特征点的实时检测,对原算法进行了改进,提出了一种基于面密度插值法和双重极值点约束的新方法.该方法显著提升了SIFT特征点的尺度不变性,同时有利于提高定点数的计算精度.在此基础上,设计了一种高效率的硬件计算方案,将所有的计算步骤都实现在了流水线结构中,并在FPGA上完成了开发工作.与现有研究成果相比,这种高效的方案非常节约硬件资源,大大降低了硬件成本,同时又大幅度提高了计算精度.系统能够在采集图像的同时完成特征点的检测.对于360×288大小的图像,其理论最高处理能力为303帧/秒;由于受到摄像头的图像采集速度限制,目前的实际处理速度是25帧/秒.     

Positionally defined, binary semiconductor nanoparticles synthesized by scanning probe block copolymer lithography

We report the first method for synthesizing binary semiconductor materials by scanning probe block copolymer lithography (SPBCL) in desired locations on a surface. In this work, we utilize SPBCL to create polymer features containing a desired amount of Cd(2+), which is defined by the feature volume. When they are subsequently reacted in H(2)S in the vapor phase, a single CdS nanoparticle is formed in each block copolymer (BCP) feature. The CdS nanoparticles were shown to be both crystalline and luminescent. Importantly, the CdS nanoparticle sizes can be tuned since their diameters depend on the volume of the originally deposited BCP feature.     

Catalytic oxidation of benzene with ozone over nanoporous Mn/MCM-48 catalyst

The catalytic oxidation of a representative volatile organic compound, benzene, with ozone at a low temperature was investigated. A nanoporous MCM-48 material with a high specific surface area was used as the support for the catalytic oxidation for the first time. Mn, which has high activity at a low temperature, was used as the metal catalyst. To examine the effect of the Mn precursor, MCM-48 was impregnated with two different Mn precursors: Mn acetate and Mn nitrate. The characteristics of the synthesized catalysts were analyzed by Brunauer Emmett Teller surface area, X-ray diffraction, X-ray photoelectron spectroscopy, and temperature-programmed reduction. MCM-48 impregnated with Mn acetate showed higher catalytic activity than MCM-48 impregnated with Mn nitrate. This result was attributed to the better dispersion within nanoporous MCM-48 and higher oxygen mobility of Mn oxides produced by Mn acetate. The catalytic activity was also shown to depend closely on the ozone concentration.     

木薯糊化淀粉海绵制备工艺研究

采用冷冻干燥法制备糊化木薯淀粉海绵,在单因素实验基础上进行正交实验,考察预冻温度、预冻时间、淀粉和水的比例对木薯淀粉海绵吸水率的影响,确定吸水率最佳的海绵制备工艺条件为:淀粉和水比例为1∶30、预冻温度-60℃、预冻时间12h。