大学英语生态化教学模式构建——以三亚学院为例

概述生态化教学模式的内涵及特点。结合三亚学院的实际情况,探讨如何通过创建师生和谐的生态化教学环境、设立生态化教学目标、选择生态化教学内容、设置生态化课程体系、实行生态化课程模式、采用过程化评估等措施构建生态化大学英语教学模式。认为生态化教学模式能够促进教师、学生和教学环境各要素的动态、持续、健康发展。

过程化的写作评估模式

本文介绍了作者提出的基于语料库的过程化写作评估模式 ,它由以下 5个步骤组成 :1)建立写作评估的参数量表 ;2 )收缴学生作文 ,建立作文语料库 ;3)用语料库方法 ,按照设定的评估量表对学生的作文进行标注 ;4 )借助计算机 ,对标注的作文语料库进行统计分析 ;5 )为每个学生生成评估报告 ,并建立学生写作分析档案。过程化评估模式的优势体现在 5个方面 :1)具有诊断性功能 ;2 )个性化评估 ;3)积极的反拨作用 ;4 )灵活性强 ;5 )教学。

Real-time reliability evaluation based on damaged measurement degradation data

A method was proposed to evaluate the real-time reliability for a single product based on damaged measurement degradation data.Most researches on degradation analysis often assumed that the measurement process did not have any impact on the product's performance.However,in some cases,the measurement process may exert extra stress on products being measured.To obtain trustful results in such a situation,a new degradation model was derived.Then,by fusing the prior information of product and its own on-line degradation data,the real-time reliability was evaluated on the basis of Bayesian formula.To make the proposed method more practical,a procedure based on expectation maximization (EM) algorithm was presented to estimate the unknown parameters.Finally,the performance of the proposed method was illustrated by a simulation study.The results show that ignoring the influence of the damaged measurement process can lead to biased evaluation results,if the damaged measurement process is involved.

Risk Assessment Based on Fault Tree Analysis for Damaged Pipe Repair During Operation in Petrochemical Plant

In petrochemical plant, the in-operation repairing is usually a repairing strategy with pressured inoperation repairing for avoiding huge economic losses caused by unplanned shutdown when some slight local leakage happens in pipes. This paper studies the effects of repairing strategies on the failure probability of the pipe systems in process industries based on the time-average fault tree approach, especially the in-operation repairing strategies including pressured in-operation repairing activities. The fault tree model can predict the effect of different repairing plans on the pipe failure probability, which is significant to the optimization of the repairing plans. At first pipes are distinguished into four states in this model, i.e., successive state, flaw state, leakage state and failure state. Then the fault tree approach, which is usually applied in the studies of dynamic equipment, is adopted to model the pipe failure. Moreover, the effect of pressured in-operation repairing is also considered in the model. In addition, this paper proposes a series of time-average parameters of the fault tree model, all of which are used to calculate node parameters of the fault tree model. At last, a practical case is calculated based on the fault tree model in a repairing activity of pipe thinning.

Assessment of Weathering of Construction Blocks and Mortar in Historical Monuments

Monitoring and assessment of monuments of cultural heritage is just a small part of all measures necessary for their protection and preservation. Many of these monuments are built of stone and the binder used to bond the construction blocks after a lengthy period of time loses its properties. The loss of binding material or changes in its properties substantially endangers the stability of the monuments thus constituting a menace not only for the visitors, but also for the conservation work. One of such monuments is the Step Pyramid of Djoser in Egypt. In this pyramid different artificial compositions are used as binder and its application in different areas of the pyramid is uneven and almost undistinguishable. Currently it is only possible to appraise the state of preservation of the mortar as a result of weathering process. This research allows identifying up to six weathering types and their intensities. This typology was developed on several sample areas verifying its validity in situ. Since there is no possibility to carry out direct instrumental measurements or take any samples, the classification developed is just empirical and not general. However, it provides relevant support for the development of conservation plans.

Degradation process assessment of prestressed concrete continuous bridges in life-cycle

To accurately evaluate the degradation process of prestressed concrete continuous bridges exposed to aggressive environments in life-cycle,a finite element-based approach with respect to the lifetime performance assessment of concrete bridges was proposed.The existing assessment methods were firstly introduced and compared.Some essential mechanics problems involved in the degradation process,such as the deterioration of materials properties,the reduction of sectional areas and the variation of overall structural performance caused by the first two problems,were investigated and solved.A computer program named CBDAS(Concrete Bridge Durability Analysis System) was written to perform the above-metioned approach.Finally,the degradation process of a prestressed concrete continuous bridge under chloride penetration was discussed.The results show that the concrete normal stress for serviceability limit state exceeds the threshold value after 60 a,but the various performance indicators at ultimate limit state are consistently in the allowable level during service life.Therefore,in the case of prestressed concrete bridges,the serviceability limit state is more possible to have durability problems in life-cycle;however,the performance indicators at ultimate limit state can satisfy the requirements.

Thermodynamic Performance Assessment of IGCC Power Plants with Various Syngas Cleanup Processes

The present work explores how much IGCC can benefit from warm gas clean-up（WGCU）in comparison with conventional cold gas clean-up（CGCU） and what are the respective contributions of dry particulates removal and warm gas desulfurization （WGD） in a plant-wide point of view. Influences of key parameters of WGD on ther- modynamic performance of IGCC plant including desulfurization temperature, oxygen concentration in the re- generation stream, and H2S removal efficiency are discussed. It is obtained that the net efficiency of IGCC with full WGCU experiences an improvement of 1.77 percentage points compared with IGCC with full CGCU. Of which, dry particulates removal without water scrubber contributes about 1 percentage point. The influence of desulfurization temperature on thermodynamic performance of IGCC with WGD is weak especially when it is higher than about 350~C, which indicates that more focus should be put on investment cost, technical feasibility and sorbent stability for the selection of optimal operation temperature. Generally, 2%-3% of oxygen concentra- tion in the regeneration stream might be reasonable in a thermodynamic performance point of view. In addition, the improvement of 0.31 percentage points can be obtained by removal of H2S in the syngas from 27 ppm to 3 ppm.