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。     

Comparison of the univariate and multivariate methods in the optimization of experimental conditions for determining Cu, Pb, Ni and Cd in biodiesel by GFAAS

Experimental design was used as a tool to define the optimum pyrolysis and atomization temperatures for four analytes (Cu, Pb, Ni and Cd) in biodiesel samples. Two chemical modifiers (Pd + Mg and W) and two distinct sample preparation procedures (microemulsion and wet digestion in a focused microwave system) were also investigated. The pyrolysis and atomization temperatures were optimized using 2⁴ factorial design for Cu, Pb, Ni and Cd, with 16 assays carried out for each analyte. The results for Cu and Pb indicated that variables of sample preparation for digestion by focused microwave was the most important one for both analytes. The pyrolysis and atomization temperatures applied were 1000 °C and 2200 °C for Cu and 500 °C and 2000 °C for Pb. None of the variables analyzed here were important for Ni, and the pyrolysis and atomization temperatures chosen for this element were 800 °C and 2300 °C. A different factorial design was used for Cd. The variables of medium and modifier were not important for this element, and the lowest temperatures, Tp-500 °C and Ta-1400 °C, were chosen based on this second design. The importance of factorial design in the simultaneous optimization of several variables studied by GFAAS was confirmed, for it involves fewer experiments and hence, lower costs, greater speed and higher efficiency.     

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。     

聚丙烯纤维混凝土性能的试验研究

结合水电工程对聚丙烯纤维混凝土的基本性能进行试验研究 ,结果表明 ,在混凝土中掺入一定量的聚丙烯纤维是克服混凝土开裂的有效途径 .纤维在混凝土中所形成的乱向支撑体系 ,产生一种有效的二级加强效果 ,能较大幅度提高混凝土的抗裂性能 ,改善混凝土的抗渗、抗冲击及耐磨性能等 .在水工混凝土中掺加一定量的聚丙烯纤维可以有效地提高混凝土的整体性能 .