铜硫化矿熔炼过程的能源消耗(下)

利用热化学模型和工业数据,对以下工艺方法铜硫化矿熔炼过程中能源消耗进行计算:a)闪速熔炼+闪速吹炼;b)艾萨熔炼+PS转炉吹炼;c)三菱法连续铜熔炼和吹炼;d)诺兰达/特尼恩特连续熔池熔炼+PS转炉吹炼。对于这些方法,作业的范围包括渣中有价金属的回收,工艺过程中烟气的热回收,以及工艺过程中烟气和环保烟气中SO2的回收,在此项研究中采用了单元计算法,因此可以快速评估其他工艺流程,如"闪速熔炼+PS转炉吹炼"。尽管天然气是用于计算的重要燃料,但该模型也可很容易计算出替代燃料所产生的影响。     

不同方法制备的钛及钛合金管坯组织与性能研究

分别用压力机热挤压法和两辊斜轧穿孔法获得钛及钛合金管坯,对比分析了两种不同方法制备的TA2,TA18,TC4管坯的显微组织和室温力学性能的差异。结果表明:管坯的力学性能受加热温度、变形量等因素影响,挤压管坯的组织均匀细小而斜轧穿孔的组织粗大,挤压工艺优于斜轧穿孔工艺。     

哈密硅灰石制备白炭黑工艺的研究

以哈密硅灰石为原料,分别通过直接制备、硅灰石矿预提纯及分级制备3种工艺方法,制备了3种白炭黑产品。对所得产品按HG/T 3061-1999进行分析,其中3种产品的SiO2含量均大于90%,比表面积分别为63.83m2/g、90.79m2/g、301.84m2/g。通过SEM、TEM、XRD等手段检测了产品的性能。TEM图像显示白炭黑的形貌近似球状粒子。XRD分析显示分级制备白炭黑为无定型结构,而直接制备和预提纯制备白炭黑含有一定的晶型结构。     

Design and formal verification of a CEM protocol with transparent TTP

In certified email (CEM) protocols, trusted third party (TTP) transparency is an important security requirement which helps to avoid bad publicity as well as protecting individual users’ privacy. Cederquist et al. proposed an optimistic certified email protocol, which employs key chains to reduce the storage requirement of the TTP. We extend their protocol to satisfy the property of TTP transparency, using existing verifiably encrypted signature schemes. An implementation with the scheme based on bilinear pairing makes our extension one of the most efficient CEM protocols satisfying strong fairness, timeliness, and TTP transparency. We formally verify the security requirements of the extended protocol. The properties of fairness, timeliness and effectiveness are checked in the model checker Mocha, and TTP transparency is formalised and analysed using the toolsets µCRL and CADP.     

基于Profibus-DP现场总线的矿井提升机控制系统

介绍了基于Profibus-DP现场总线的矿井提升机控制系统的研究,概述了Profibus-DP现场总线的网络拓扑结构及其对提升机控制的实现,给出了控制系统上位机、下位机的软件设计,并利用PLC实现DP通讯,使得提升机控制系统的稳定性、安全性和生产效率都有所提高。     

iPTT: peer‐to‐peer push‐to‐talk for VoIP

This paper proposes iPTT, a peer‐to‐peer (P2P) Push‐to‐Talk (PTT) service for Voice over IP (VoIP). In iPTT, a distributed and mobile‐operator independent network architecture is presented to accelerate the deployment of the PTT service. Based on the serverless architecture, we develop two mechanisms, that is, flooding‐based floor control mechanism (FFC) and tree‐based floor control mechanism (TFC), for real‐time talk‐burst determination. The determination algorithms and the corresponding message flows for these two mechanisms are designed to show the feasibility of FFC and TFC. The performance of FFC and TFC is investigated through our analytical and simulation models in terms of the determination latency and the number of floor‐control message exchanges. Copyright © 2008 John Wiley & Sons, Ltd.     

川西新场气田须二气藏水体动态分布与水化学特征

为直观、详细地论述川西新场须二气藏气井产出水状况,文中将气井产出水分为凝析水、地层水、夹层水或残留地层水3个大类。研究发现,构造主体部位的气井在产出地层水之前大多经历过一段较长时间的凝析水产出阶段;之后南北部边水才侵入构造主体;而构造主体的东西部产出夹层水或残留地层水。其主要原因是随着气藏开采,地层能量下降,边部水体沿着南北走向断层入侵到高部位,使得高部位气井大量产水;至于构造主体的东西部,由于远离断层,微裂缝不发育,气井产水量较少。总体而言,由于产出水类型不同,其水化学成分亦存在较大差异,表现为凝析水矿化度低、地层水矿化度高、夹层水或残留地层水的矿化度则介于两者之间。气井产出水化学性质差异性源自水-岩反应环境、流体压力、天然气浓度以及pH值等影响因素的变化。因为随着气井天然气的采出,流体压力下降、天然气浓度降低,盐离子的溶解度亦降低,所以构造主体产出地层水时,其Ca²⁺浓度较南北边部的要低,水体中出现少量Ca沉淀。     

A High-Order Difference Scheme for the Generalized Cattaneo Equation

A high-order finite difference scheme for the fractional Cattaneo equation is investigated. The $L_1$ approximation is invoked for the time fractional part, and a compact difference scheme is applied to approximate the second-order space derivative. The stability and convergence rate are discussed in the maximum norm by the energy method. Numerical examples are provided to verify the effectiveness and accuracy of the proposed difference scheme.     

高含水原油流动沉积实验装置研制

设计并搭建高含水原油实验装置,装置主要包括试验管路、油水分离系统、数据采集系统和电路控制系统。设计出有机玻璃管水浴实验段,以便观测流动形貌和初始沉积过程,基于射流喷射混合器原理完成油水混合装置的设计,使管内流动状态与现场实际相符合。为保证在实验过程中游离水和原油的有效分离,以游离水分离器为基础,设计出适用于高含水原油分离的油水分离器。同时设计出配套数据采集系统和电路控制系统,有效解决了实验数据采集和参数调控的问题。经过实验验证,该实验装置能够较好地适应高含水原油流动沉积研究。     

Comparative analysis of residence and diffusion times in rotating bed used for biogas upgrading

Rotating bed can be used in desorption operation of biogas upgrading as a new technology. For enough time to desorb, it is important to study the relationship between the residence time of liquid in rotating bed and the material diffusion time of liquid droplet in desorption process. By theoretical deduction, the exponential relation between residence time and liquid flow rate and rotational speed and kinematic viscosity is obtained. By analyzing the solution of nonlinear partial differential equation, the time law of material diffusion in the droplet is obtained. Moreover, by comparing the residence and diffusion times, the diffusion time can be within or out of residence time range, which has a direct relationship to rotational speed and liquid flow. By experiment, the comparison between residence and diffusion times is more realistic when the rotational speed is higher.