水环境研究的回顾与展望

简要介绍水环境研究所组建近10年来取得的主要科研成果。其创新性研究工作主要体现在：（1）水环境监测与标准化体系建设。实现了从常规污染物监测到技术难度较大的痕量有毒有害污染物监测的转变,水质监测技术实现了标准化;（2）水环境保护与水污染控制。开展了水环境演化机理、水环境污染模拟及水污染修复等理论的研究与实践;（3）水利水电工程的生态环境影响研究。着重关注了重大水电工程因改变水文情势所引发的生态与环境问题,为我国重大水利工程的规划设计和运行管理提供了技术支持;（4）饮用水安全保障。研究了饮水安全保障技术及相关设备;（5）水环境综合管理。研究了基于3S技术的水环境信息管理技术,协助业务主管部门开展了大规模的水环境状况调查,取得了多项创新性成果。最后提出了水环境研究今后的展望。     

金刚石抗动载测定仪的设计

金刚石盍功指标是金刚石钻头设计的主要指标之一。为此，文章介绍了一种金刚石等脆 非金属颗粒及超硬复合片抗冲击硫碎能的测试系统，阐述了金刚石单晶和复合片测试的基本原理，并论述了单晶测试电路和复合片测试电路物设计以及软件的设计方法，简述了先进先出存储器、微型打印机等与单片机接口的设计方法。     

南水北调西线工程方案优化

通过收集调研大量水文、地质、水资源、工程技术资料, 在现有研究基础上论述西线工程方案优化, 提出工程研 究面临的主要问题; 利用多指标比对法, 从西线工程调水断面下移自流方案和抽水方案入手, 通过调水河流可调水 量、环境影响、移民范围、投资费用和经济效益等指标探讨方案的优劣, 论证工程下移自流方案的可行性与优越性。 同时, 为减轻调水对生态、环境、社会等方面的影响, 分析并拟定金沙江、雅砻江、大渡河多年平均年调水总量为 170 亿 m3。研究成果可为未来工程建设决策提供重要技术依据。     

Policy impacts on pedagogical practice and ICT use: an exploration of the results from SITES 2006

The Second Information Technology in Education Study (SITES) 2006 results reveal that principals' perceived presence of lifelong learning‐related pedagogical activities in their schools had changed markedly since the same data was collected in 1998 in SITES‐M1. More intriguing was the fact that the directions of the changes were quite different depending on the education systems concerned – many of the Asian countries reported very high increases while some of the European countries reported large drops over the same 8‐year period. This paper reports statistical evidence that the observed ‘pendulum swing’ reflects actual changes in teaching practices in these countries. Exploratory multilevel analyses results consistently show that national means of principals' vision can be used as a system‐level indicator predicting national means of pedagogical orientations in schools several years later. These findings also indicate the possibility of the ‘pendulum effect’ being a consequence of system‐level policy differences in the countries participating in the two SITES studies.     

Development of a parsimonious GA-NN ensemble model with a case study for Charpy impact energy prediction

A parsimonious genetic algorithm guided neural network ensemble modelling strategy is presented. Each neural network candidate model to participate in the ensemble model is structurally selected using a genetic algorithm. This provides an effective route to improve the performance of the individual neural network models as compared to more traditional neural network modelling approaches, whereby the neural network structure is selected through some trial-and-error methods or heuristics. The parsimonious neural network ensemble modelling strategy developed in this paper is highly efficient and requires very little extra computation for developing the ensemble model, thus overcoming one of the major known obstacles for developing an ensemble model. The key techniques behind the implementation of the ensemble model, include the formulation of the fitness function, the generation of the qualified neural network candidate models, as well as the specific definitions of the assemble strategies. A case study is presented which exploits a complex industrial data set relating to the Charpy impact energy for heat-treated steels, which was provided by Tata Steel Europe. Modelling results show a significant performance improvement over the previously developed models for the same data set.     

Galvanising and galvannealing behaviour of B added TiNb IF high strength steel

Abstract

Solid solution strengthened steels stabilised with Ti and Nb are known to have poor galvanising and galvannealing properties. When these steels are alloyed with boron to prevent cold work embrittlement, the selective oxidation processes are influenced by the presence of B. The continuous galvannealing process has therefore been simulated in a laboratory in order to study the effect of B on the fundamental surface and interface processes that control the wetting of the surface by liquid Zn, the inhibition layer formation, and the Fe-Zn reaction.     

PTA装置中化学品对环境影响探讨

通过对PTA装置的危险化学品识别和毒性物料危害分析,运用化学品的持久性、生物累积性和毒性数据,对PTA装置生产异常时,主要原、辅料对环境影响风险进行梳理和分类,提出可行的控制措施来降低风险,做好人员防护。     

平面广告设计中的“视觉冲击力”

"视觉冲击力"不是简单意义上的视觉印象和视觉效果,它所揭示的是对平面广告设计作品的审美过程、设计目的、设计信息等进行积极思考、判断和接收的动力。     

土体的压实能耗和合理压实度要求

推导了土体在压实过程所需施加的能量,分别在线性和非线性条件下给出了土体压实能耗的表达式,并进行了具体的计算分析和比较。分析结果以及一些计算数据表明在高密阶段,土体的进一步压实将引起能耗的急剧增加,因此,对提高压实度的要求一定要慎重.并认为如何确定一个合理的压实度要求,还需要做大量的试验研究.     

Investigation of Die Stress Profiles During Powder Compaction Using Instrumented Die

The die stress profiles during compaction of commercially pure titanium (Ti) and commercial lubricated iron (Fe) powders were experimentally investigated using an instrumented die. The die was designed to simulate double-action pressing, and a detailed stress profile was measured along the height of the die using multiple custom-made strain gage pins. The stress history shows that residual stress remained in the die in the radial direction after the axial compaction stress was removed from the powder. Also, the stress profile at the maximum axial stress and the residual stress profile were observed to be symmetric across the height of the compact for both powders, but both have a unique shape for each powder. For both the stress profile at the maximum axial stress and the residual stress profile, the unlubricated Ti powder produced a much higher radial stress at the center of the compact with a steep pressure gradient on both top and bottom of the compact, while the lubricated Fe powder produced a rather uniform radial stress distribution along the height of the compact. This article was presented at Materials Science & Technology 2007, Automotive and Ground Vehicles symposium held September 16–20, 2007, in Detroit, MI.