Experimental investigation of burning rates of pure ethanol and ethanol blended fuels

A fundamental experimental study to determine the burning rates of ethanol and ethanol-blended fossil fuels is presented. Pure liquid ethanol or its blends with liquid fossil fuels such as gasoline or diesel, has been transpired to the surface a porous sphere using an infusion pump. Burning of the fuel takes place on the surface of the porous sphere, which is placed in an air stream blowing upwards with a uniform velocity at atmospheric pressure and temperature under normal gravity conditions. At low air velocities, when ignited, a flame envelopes the sphere. For each sphere size, air stream velocity and fuel type, the fuel feed rate will vary and the same is recorded as the burning rate for that configuration. The flame stand-off distances from the sphere surface are measured by post-processing the digital image of the flame photograph using suitable imaging software. The transition velocity at which the flame moves and establishes itself at the wake region of the sphere has been determined for different diameters and fuel types. Correlations of these parameters are also presented.     

侧钻井投球调剖技术室内模拟及方案设计

为解决侧钻井转注水后分层注水难度大的问题,将投球调剖技术应用到侧钻井注水中,实现资源的重新利用.介绍了投球调剖技术的工作原理和技术优点,阐述了调剖球的性能特征,通过实验室建立侧钻井仿真可视模型的方式,进行了侧钻井中投球调剖的物理模拟实验.实验验证了调剖球在侧钻井中封堵的可行性,依据大量数据分析了调剖球封堵炮眼的规律,确定了不同工况下投球位置、井筒内流量对封堵效果的影响.提出了靠近目标层投球和适当控制流量的方法,该方法可实现对调剖球在井筒中运动的控制,给出了不同注入位置及各层流量比下最优的投球方式、流量大小和投球数量,为现场施工提供了参考依据.     

Hyperelastic large deformations of two-phase composites with membrane-type interface

The composite under investigation consists of two phases which are bonded together through a membrane-type interface. The work reported in this paper aims at studying the hyperelastic large deformations of this composite while accounting for interfacial stress effects. A variational formulation for a general traction boundary value problem of the composite is provided, leading to the local bulk and interfacial equilibrium equations and to the traction boundary conditions. Assuming that each bulk phase is incompressible and characterized by an energy density function depending only on the trace of the right Cauchy-Green bulk strain tensor and that the interface is compressible and defined by an energy density function being isotropic with respect to the right Cauchy-Green surface strain tensor, exact solutions are given for the simple axial extension, simple torsion and out-of-plane shear of a fiber-reinforced cylinder, and a closed-form solution is also found for a hollow composite sphere subjected both to an internal pressure and an external pressure. These analytical results are further specified and discussed in the particular case where each bulk phase is described by an incompressible Neo-Hookean law and the interface is specified by a compressible Neo-Hookean law. Apart from their own usefulness, the results obtained in this work can serve as benchmarks for relevant numerical methods.     

Synthesis and electrochemical characterization of carbon spheres as anode material for lithium-ion battery

Carbon spheres were synthesized by the thermal decomposition of RF precursor which was synthesized by surfactant-assisted polycondensation of resorcinol with formaldehyde. The morphology of precursor was preserved during the decomposition process. EDS, TG, SEM, CV and galvanostatic charge-discharge methods are used to characterize the composition, morphology, and electrochemical performance of carbon spheres. The results revealed that these carbon spheres had a spherical morphology, smooth surface and probable size of about 400 nm. When the carbon spheres were used as anode materials for lithium-ion battery, they exhibited a high lithium storage capacity and good cycle performance. In addition, the possible progress for the preparation of carbon spheres was proposed.     

蒸球进汽系统的改造和蔗渣蒸煮工艺

随着甘蔗渣制浆原料的不断变化并为满足生产和蒸煮工艺的需求,蒸球设备在经过单一、三条和四条蒸汽管进行蒸煮的不断改进过程中,采用了目前较为先进的自动控制进汽系统和32段蒸煮工艺曲线进行生产,使蒸煮质量稳定、原浆生产成本低,达到挖掘潜能和节能减排的目的。     

雷达极化问题和铁氧体变极化技术

描述了雷达极化问题的基本概念,提出了两类铁氧体全(变)极化器的机制。从理论上解决了这种器件的收发功能,并介绍了它在极化雷达中可实现极化扫描和接收的功能。     

LHPG法单晶光纤生长中的熔区控制技术

采用激光加热基座生长法 (LHPG)生长单晶光纤 ,研究晶体源棒的熔球大小、籽晶点入深度与熔区长度、生长速度、生长质量的关系及控制技术 ,得到了生长优质单晶光纤过程中的各控制参数最佳值