大型铝型材挤压机的安装与调试

对55MN大型铝型材挤压机的设计特点、安装调试情况,以及在调试过程中的进度、步骤及注意事项进行了详细论述。该挤压机生产线已安装完毕并试生产成功,其设计特点及安装调试的相关技术数据,将对今后大型挤压机的组装与调试工作起到一定的指导作用。     

TRT机组调试问题及技术措施

安阳钢铁公司2#TRT机组在调试过程中出现了一系列问题,通过对试验数据的分析提出了解决办法,为同类机组的调试提供了调试思路及借鉴方法。     

西门子STEP7程序模拟调试系统

本文叙述了WINAC的工作原理,提出了一种STEP7程序模拟调试的方法。它运用VB、WINAC、STEP7实现了对STEP7程序的编辑、修改、调试和监视等功能。     

3 200 m3高炉区域变电站35 kV变压器安装与调试

全面介绍了大型变压器的安装、调试方法及安装、调试前的准备工作.在变压器现场安装调试过程中应用该调试方法,达到了预想的效果.     

带钢横切线圆盘剪稀油润滑系统调试分析

以首钢京唐公司30万t热轧带钢横切线稀油润滑系统的调试为案例,介绍了带钢横切线圆盘剪、碎边剪稀油润滑系统调试中出现的问题,并对问题进行了分析,给出了解决方案。对类似横切线的冷加工车间稀油润滑系统设计、制造和调试有参考价值。     

浅谈焦化厂A/A/0废水处理系统调试

本文对焦化厂废水处理系统调试过程介绍的同时，分析了废水处理系统的开工基础和方案依据，阐述了系统调试运行步骤和思路，探讨了影响系统调试运行的因素。     

浅析高压同步电机综合保护装置的调试

结合一台7800kw同步电机的调试过程,对微机综合保护装置的定值设定、保护逻辑及试验调试中存在的问题进行了简要分析,给出了解决办法。     

测控系统调试与运行

随着计算机技术、通信技术和网络技术的飞速发展,测控系统的设计也步入了快速发展时期,作为测控系统的调试运行是整个系统设计中一个非常重要的过程。本论文通过对测控系统运行调试,使它能够达到设计要求。主要是对电路板的功能实现以及调试,并对电路板进行布局,制作出的电路板能够满足系统的需求。     

MAXI-DC全数字直流调速系统

介绍了MAXI－DC全数字直流调速系统的软件构成及系统的调试方法,其所述调试方法对调试其它全数字直流调速系统有较高的参考价值。     

双头回转式圆盘剪结构设计和调试分析

结合参与的国产化连续酸洗机组的现场经验,对双头回转式圆盘剪的结构形式、技术参数及现场调试过程进行了分析和总结,对后续类似连续酸洗机组圆盘剪的优化设计和缩短设备调试时间起到了一些积极的作用。     

高校档案服务创新的必要性及实施路径研究

档案的价值和意义是通过为社会服务而实现的,高校档案工作的服务性,是高校档案馆赖以生存和发展的基础。创新高校档案服务机制是信息社会发展的必然要求,是高等教育改革的必然要求,是高校档案馆自身发展的必然要求。要实现高校档案服务创新,一是要建立现代化的管理方式、服务手段和服务方式;二是拓展档案信息的校内服务功能;三是凝练一支整体素质过硬的档案工作团队;四是加强学校服务和社会服务功能逐步渗透。     

Equivalent Beam-Column Method to Estimate In-Plane Critical Loads of Parabolic Fixed Steel Arches

The objective of this paper is to investigate the characteristics of critical loads for parabolic fixed steel tubular arches. An advanced nonlinearity finite-element program, taking into account the geometric and material dual nonlinearity, is employed. The influence of nonlinearity and initial crookedness on arch critical load is discussed. It is found that the effect of rise-to-span ratio on the critical load of arch is significant. Therefore, a new equivalent beam-column method is proposed for estimating the corresponding in-plane critical loads of arch, in which a buckling factor K1 is employed to consider influence of rise-to-span ratio and a reduction factor K2 to consider the effect of initial crookedness. Pragmatic formulas and tabulated data are provided based on the present different Chinese design codes. It is proved that the presented method is sufficiently accurate to predict the in-plane critical load of parabolic fixed steel arch subjected to compression or to both bending and compression.     

Bayesian Model Calibration Using Geotechnical Centrifuge Tests

The predicted performance using a geotechnical prediction model is expected to deviate from reality. A practical approach to assess the model error is through calibration with observed performances in physical model tests. In this paper, a Bayesian framework of model calibration using centrifuge modeling tests is proposed and the procedure of model calibration is illustrated. Two centrifuge tests conducted to investigate the performance of soil slopes under rainfall conditions are used to calibrate a coupled hydromechanical analysis model. It is found that for centrifuge tests with different levels of soil variability, the test with a smaller variability of soil properties is more efficient for model calibration. According to the concept of random field, a centrifuge model with a larger model size and accelerated to a lower acceleration is better for model calibration. When the discrepancy between the performance interpreted from the centrifuge model and the field performance is small, the improvement of the reliability estimation for a new slope is significant. However, when there is little information about the discrepancy, the reliability estimation cannot be significantly improved by the information from centrifuge modeling. The proposed procedure is shown to be able to quantify the calibration effects of centrifuge tests and may be used to achieve a more reliable calibration.     

Fully Probabilistic Framework for Evaluating Excavation-Induced Damage Potential of Adjacent Buildings

This paper presents a framework for a fully probabilistic analysis of the potential for damage to buildings adjacent to an excavation. Herein, the damage potential index (DPI), which is a function of angular distortion and lateral strain, is used to assess building damage potential. A serviceability limit state is established in which the resistance is expressed in terms of the “limiting” DPI, and the load is represented by the “applied” DPI. In this context, damage to the building adjacent to an excavation is said to occur deterministically if the applied DPI is greater than the limiting DPI. For the fully probabilistic analysis, both parameter and model uncertainties of the limiting and applied DPIs are first characterized. The analysis framework is then presented and demonstrated with a case history. Finally, sensitivity analysis is performed to identify the factors to which the probability of damage is most sensitive and to analyze the effect of various assumptions of the input parameters on the computed probability of building damage.     

气体搅拌用透气砖阻力系数的测试

在实验室测定了工业用的狭缝型透气砖进出口压力差及气体出口速度,得出透气砖的阻力系数近似为44/Re,流动状态可近似认为呈层流,阻力系数与相对粗糙度无关,仅是雷诺数的函数,阻力损失与出口速度成正比。从而可计算出透气砖阻力损失,进而确定透气砖气体进口压力。在工业应用中,正常吹氩的压力差不大时,透气砖阻力系数≈0.07。     

Micromechanical Explanation of Elasticity and Strength of Gypsum: From Elongated Anisotropic Crystals to Isotropic Porous Polycrystals

Gypsum is made up of interlocked and elongated crystals. The random nature of its morphology suggests to resort to homogenization of random media to investigate its mechanical properties from the scale of the single crystals upwards. Unfortunately, the usual homogenization schemes fail to quantitatively predict the influence of the porosity on the effective Young’s modulus of gypsum. This is clearly due to the inability of such approaches to take into account the elongated nature of the crystals. A modification of the classical self-consistent scheme is proposed. It is validated against elastic characteristics computed by finite element analyses, and also against experiments on real dried gypsum samples (with empty pores). Finally, a strength model based on brittle failure is presented. The whole strength domain in the space of macroscopic principal stresses is derived. The comparison to experimental data in both simple tension and simple compression is remarkably good.     

Damage Modeling of Saturated Rocks in Drained and Undrained Conditions

A new anisotropic damage model is proposed to describe the mechanical and poromechanical behavior of brittle rocks in drained and undrained conditions. Although phenomenological, the model is based on physical grounds of micromechanical analysis. Induced damage is represented by a second rank tensor, which is related to the density and orientation of microcracks. Damage evolution is related to propagation of the microcracks. The effective elastic compliance of the damaged material is obtained from a specific form of the Gibbs free enthalpy function. Irreversible damage-related strain due to residual opening of microcracks after unloading is also captured. The originality of our approach is that a poromechanical model of a saturated medium is constructed by extension of the mechanical model for dry material using micromechanical relationships. All the model parameters are determined from triaxial compression tests performed on dry material. The proposed model is applied to coupled poromechanical tests performed on typical brittle rock in saturated conditions. Comparison between test data and numerical simulations shows overall good agreement. The model proposed is able to describe the main features of poromechanical behavior related to microcracks induced in brittle geomaterials.     

一种土壤改良剂余热回收利用工艺及设备研究

土壤改良剂是一种修复土壤退化的颗粒状物料。以我国年产1.3亿t的来计,制备完成后的土壤改良剂显热折合每年3.5×1013 kgce。目前,这部分显热几乎白白放散掉,基于此,本文构建、分析了一种土壤改良剂余热回收利用工艺流程及关键设备,建立了土壤改良剂余热回收竖罐气固传热解析模型,藉此确定了竖罐的结构和操作参数,为我国土壤改良剂余热回收探索了一条技术路径。研究结果表明:该工艺及装备可有效回收改良剂的显热;处理量为6 t/h时,罐体适宜的高度为2.2 m,气固水当量比为1.2;回收到的余热用于改良剂制备的回转窑中,可节约燃料22.86%。     

1,10-二氮杂菲分光光度测定钛合金中铁方法的改进

试样采用氢氟酸溶解,饱和硼酸络合,乙酸-乙酸铵作缓冲溶液控制酸度,三元有机铵盐作混合掩蔽剂,1,10-二氮杂菲分光光度法测定钛合金中铁。成功克服了传统分析方法中因受钒(4mg以上)干扰,显色液需放置隔夜后才能测定的缺陷,大大缩短分析时间,获得较满意的结果。该方法准确度高,分析结果重现性较好。     

Extending Monte Carlo Simulations to Represent and Propagate Uncertainties in Presence of Incomplete Knowledge: Application to the Transfer of a Radionuclide in the Environment

This work is devoted to some recent developments in uncertainty analysis of environmental models in the presence of incomplete knowledge. The classical uncertainty methodology based on probabilistic modeling provides direct estimations of relevant statistical measures to quantify the uncertainty on the model responses thanks to a nice mixing between Monte Carlo simulations and the use of efficient statistical treatments. However, this approach may lead to unrealistic results when not enough information is available to specify the probability distribution functions (pdfs) of input parameters. For example, if a fixed (i.e., the pdf is a Dirac distribution) variable is unknown between a and b, the proper way to model this knowledge is to consider a set of δc distributions (a δc distribution means that the probability that the parameter is equal to c is 1 and 0 elsewhere), c belonging to [a,b]. This is quite different from assume an equidistribution. Thus, to respect the real state of knowledge in industrial applications, a new modeling based on the theory of evidence is introduced. It allows an extension of classical Monte Carlo simulations by relaxing assumptions related to the choice of probability distribution functions and possible dependencies between uncertain parameters. To illustrate the principle of our modeling, a comparison with the probabilistic modeling is given in the case of the transfer of a radionuclide in the environment.