管内装元件强化传热的技术经济评价

提出了一种管内装元件强化传热的技术经济评价方法，此方法综合考虑了强化换热器管内传热膜系数的提高和管内流体阻力的增大，与普通的管壳式换热器相比，所带来的投资费用和使用费用变化，这个变化量可用净现值增量△NPV来表示。根据△NPV值来评价强化传热技术，从而为强化传热技术的开发和推广及进行决策提供指导。     

Method to Characterize the Air Flow and Water Removal Characteristics During Vacuum Dewatering. Part II—Analysis and Characterization

This is part II of a study reported earlier on a method to characterize the air flow and water removal characteristics during vacuum dewatering. This article presents experimental data and analysis of results from the use of a cyclically actuated vacuum dewatering device for removing moisture from wetted porous materials such as paper with the intermittent application of vacuum and accompanying air flow though the material. Results presented include sheet moisture content as a function of residence time and hence water removal rate under a variety of process conditions. Also, experimental results on air flow through the wet porous structure and hence the role and importance of air flow during vacuum dewatering are presented. Vacuum dewatering process conditions include exit solids content between 11 and 20% solid under applied vacuum conditions of 13.5 to 67.7 kPa (4 to 20 in. Hg). Regression analysis indicated that the exit sheet moisture content exhibited a nonlinear relationship with residence time with exit solids reaching a plateau after a certain residence time. Final moisture content correlated linearly with the average overall flow rate of air through the paper sample and the basis weight of the material.     

Ionothermal synthesis of a three-dimensional zinc phosphate with DFT topology using unstable deep-eutectic solvent as template-delivery agent

A three-dimensional zinc phosphate compound with DFT topology, designated as ZnPO₄-EU1, has been synthesized by an ionothermal approach from the system HF-ZnO–P₂O₅-choline chloride-imidazolidone. Ethylenediamine, derived from decomposition of the imidazolidone component of the deep-eutectic solvent (DES) itself, is delivered to the synthesis and serves as an appropriate template for ZnPO₄-EU1. Experiments in which the synthesis conditions were varied showed that ZnPO₄-EU1 may be prepared over a wide molar ratio of P/Zn = 0.55–13.0. Powder X-ray diffraction patterns have been obtained at intervals to track the crystallization process of this material. The experimental data show that Zn₃(PO₄)₂ · 4H₂O (a dense phase) was first isolated from the DES after reaction for 1 h. Subsequently, the pure phase of ZnPO₄-EU1 was obtained with increasing crystallization time from 12 h to 72 h. The experimental results show that the nucleation and crystallization take place with relatively low levels of solvent degradation, demonstrating that zinc phosphate with a three-dimensional framework can be synthesized by in situ generation of an appropriate template using an unstable DES at high temperatures (150–200 °C).     

电力负荷削峰减载系统在珠钢电炉的应用

借助现场采集装置,在计算机上获取每一分钟的冶炼工艺电能需求量,显示当前15分钟时段已发生的电耗量,调整用户设定,实现需量自动刷新、报警和专家分析推荐后续用量;实现平稳用电并减少对电网冲击,同时降低电能最大需用量以减少成本。     

基于OpenGL和MFC的石油井管道的绘制

介绍了O penGL的知识和石油井的基本概念,利用O penGL实现石油井管道的绘制,包括石油井数据的变换和管道起始点的跟踪和角度的旋转。纹理光照效果增强图形生动性,交互操作改变图形视角。并且利用DAO数据库和L istv iew控件实现数据保存和修改。该程序能够完成石油井的管道绘制和数据保存。     

关于新农村农民公寓建设的建议——以山东省枣庄市市中区为例

近年来,随着工业化、城镇化步伐不断加快,特别是各类开发区建设的推进,土地被大量占用,部分农民失去了土地,并衍生出"失业、失房"现象,造成新的弱势群体和不稳定因素。如何实现经济发展和     

A 3-D Enlarged Cell Technique (ECT) for the Conformal FDTD Method

In this paper, we present an enlarged cell technique (ECT) to avoid the time step reduction encountered in the conformal finite-difference time-domain (CFDTD) method due to small irregular cells truncated by metallic boundaries. We focus our efforts on the discussion of the accuracy and stability of the ECT and its comparison with other conformal methods, especially the one called the uniformly stable conformal (USC) method. We also provide a simplified ECT, which is much easier to implement. In the ECT, a stability criterion is first constructed to identify instable irregular cells, i.e., those having so small an area to cause instability. Those instable cells are then enlarged into their adjacent cells to obtain a large, stable area. Careful treatment is performed on the communication between the intruding and intruded cells in terms of electromotive force by keeping the total electromotive force conservative. This technique is verified by several 3-D numerical experiments. Results show that the ECT is second-order accurate and numerically stable at the regular Courant time step limit.     

基于XML的基金会现场总线设备描述技术

本文简单介绍了基金会现场总线FF的设备描述和新一代稳定、可靠、通用的网络标记语言XML的特点，提出了一种用XML语言实现设备描述的方法。     

高压水射流射孔井眼应力数值模拟研究

水力射孔技术是一种新型完井方式,利用深穿透水力射孔技术辅助定向压裂,可实现油层改造和油井增产。考虑套管水泥环的影响,采用有限元理论结合ANSYS软件计算了高压水射流水力射孔井眼周围的应力,重点分析了水力射孔参数对井周应力的影响规律,初步研究了直井水力压裂时水力射孔对裂缝起裂的影响。计算结果表明,沿最大水平地应力方向布孔时,孔眼根部的周向拉应力最大,裂缝将会在孔眼根部起裂;选择合理水力射孔参数可有效降低地层破裂压力。研究结果可为高压水射流水力射孔辅助定向压裂提供参数优选的依据。     

住宅设计的误区

文章列举了目前住宅设计中存在的问题,反映了当前设计领域的一些现象,阐述了建筑师应当辨证地看待这一现象,对其有一个正确的认识,担负起历史责任.