The Reaction Behavior of Direct Reduced Iron (DRI) in Steelmaking Slags: Effect of DRI Carbon and Preheating Temperature

An experimental study was conducted to quantify the rate of direct reduced iron (DRI) decarburization in a steelmaking slag using the constant volume pressure increase technique. Experiments were conducted by dropping DRI pellets into molten slag at temperatures from 1773 K to 1873 K (1500 °C to 1600 °C). Subsequent experiments were carried out in which the DRI pellets were preheated while the slag temperature remained constant. The effect of the initial carbon content and the preheating temperature of the DRI on the reaction rate was investigated. The decarburization of DRI seems to comprise two stages, a reaction between the FeO and DRI followed by decarburization through the iron oxide of slag. Carbon has a significant effect on the kinetics of both stages, whereas the preheating temperature mainly influences the rate of decarburization between FeO and carbon inside the pellet.     

用自组织方法分析油藏动态

数据组合处理方法（GMDH）是70年代发展起来的一种启发式自组织建模方法,由前苏联学者伊万年科（Ivakhnenko,1970）借助生物控制论中的自组织原理,用启发式的方法提出的;它能有效的解决复杂非线性系统的建模问题.简单介绍了此方法的基本原理及计算步骤,首次探讨了在分析油藏动态方面的应用,并以南阳油田的实际数据为例,建立了区块地层压力预测模型和区块产量预测模型,其预测相对误差在5%以内,表明该方法实用可行.最后还讨论了该方法在油田开发中的应用前景.     

晶须增韧陶瓷复合材料

综述了晶须增韧陶瓷复合材料的制备方法和分类;讨论了影响增韧效果的各种因素及对陶瓷材料力学性能、抗热震性和耐磨性等方面的影响;并将近年来有关晶须增韧陶瓷基复合材料机理方面的研究进展,晶须在陶瓷材料中的应用及今后的发展趋势等作以介绍.     

Application of time-domain finite-volume method to some radiation problems in two and three dimensions

Maxwell's curl equations in the time domain are cast into a conservation form and discretized using a finite-volume procedure. The Lax-Wendroff explicit scheme is then used to solve the discretized Maxwell's equations, resulting in second-order accuracy with respect to both time and space. This time-domain scheme does not require an interlaced mesh for electric and magnetic fields. Radiation pattern and input impedance of some typical parallel-plate waveguides and mutual coupling for arrays of parallel-plate waveguides are computed and, whenever possible, compared with closed form exact or approximate solutions. Radiation patterns for a two-dimensional horn and a rectangular waveguide are presented.<>     

评价油井堵水工艺效果的含水特征曲线法

常规堵水效果评价方法,受方法本身局限,不能客观地评价油井堵水工艺效果,更无法对堵水效果进行定量分析评价。含水特征曲线法消除了含水率的偶然性波动对评价效果的影响,考虑了措施前后含水动态变化趋势,可对措施效果进行定性及定量分析评价。     

Co系Ziegler-Natta催化剂催化丁二烯-苯乙烯共聚合——Ⅰ.高顺式-1,4丁二烯-苯乙烯共聚物的合成与表征

对比了4种Ni,Co化合物分别与倍半乙基铝所组成的体系对丁二烯-苯乙烯共聚的催化活性;详细研究了Co-Al催化体系的制备条件和工艺参数对共聚物的[η],微观结构和结合St含量的影响,合成出顺式-1,4含量>95％(mol)、结合St含量为5％—10％(mol),[η]=2—2.7dL/g的丁苯共聚物,从而开发出一种新型丁苯共聚催化剂。     

Nanoscale Optoregulation of Neural Stem Cell Differentiation by Intracellular Alteration of Redox Balance

Regulation of stem cell (SC) fate, a decision between self‐renewal and differentiation, is of immense importance in regenerative medicine and has been proven to be a powerful stimulus regulating many cell functions influencing the SC fate. This study uses triphenylphosphonium‐functionalized gold nanoparticles (TPP‐AuNPs) to explore the interplay of intracellular electromagnetic (EM) exposure and the SC fate. Localized EM waves are generated inside neural stem cells (NSCs) to stimulate TPP‐AuNPs (AuNPs), targeting the mitochondria through inducing reactive oxygen species and differentiating these cells into neurons. Following laser irradiation of TPP‐AuNPs‐transfected NSCs, their differentiation to neurons is monitored by tracing the relevant markers both at the genetic and protein levels. The electrophysiology technique is further used to examine the functionality of neurons. The results confirm that TPP‐AuNPs subjected to electromotive forces have the potential to regulate cellular fate, although further investigations are still required to shed light on the mechanisms underlying the interaction of EM‐stimulated TPP‐AuNPs on cellular fate to design highly adjustable cell differentiation and reprogramming methods.     

Differential quadrature method for nonlocal nonlinear vibration analysis of a boron nitride nanotube using sinusoidal shear deformation theory

This article presents a nonlocal sinusoidal shear deformation beam theory (SDBT) for the nonlinear vibration of single-walled boron nitride nanotubes (SWBNNTs). The surrounding elastic medium is simulated based on nonlinear Pasternak foundation. Based on the nonlocal differential constitutive relations of Eringen, the equations of motion of the SWBNNTs are derived using Hamilton's principle. Differential quadrature method (DQM) for the nonlinear frequency is presented, and the obtained results are compared with those predicted by the nonlocal Timoshenko beam theory (TBT). The effects of nonlocal parameter, vibrational modes, length, and elastic medium on the nonlinear frequency of SWBNNTs are considered.     

The use of direct inverse maps to solve material identification problems: pitfalls and solutions

Material parameter identification is a technique that is used to calibrate material models, often a precursor to perform an industrial analysis. Conventional material parameter identification methods estimate the material parameters for a material model by solving an optimisation problem. An alternative but lesser-known approach, called a direct inverse map, directly maps the measured response to the parameters of a material model. In this study we investigate the potential pitfalls of the well-known stochastic noise and lesser-known model errors when constructing direct inverse maps. We show how to address these problems, explaining in particular the importance of projecting the measured response onto the domain of the simulated responses before mapping it to the material parameters. This paper concludes by proposing partial least squares regression as an elegant and computationally efficient approach to address stochastic and systematic (model) errors. This paper also gives insight into the nature of the inverse problem under consideration.