摘要：Dams and, particulary,large dams are structures with a risk potential and impacts on the environment. The impacts not only concern the immediate project area and its vicinity, but often the whole catchment area and the downstream valley. This is why regional aspects are important during design, investigation and operation. Regional geology,including all relevant geo-sciences, provides basic information for a safe and longtime operation of a project.

摘要：Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, computer modeling of nickel ore leaching process be- came a need and a challenge. In this paper, the design of experiments （DOE） theory was used to determine the optimal experimental design plan matrix based on the D optimality criterion. In the high-pressure sulfuric acid leaching （HPSAL） process for nickel laterite in ＂Rudjinci＂ ore in Serbia, the temperature, the sulfuric acid to ore ratio, the stirring speed, and the leaching time as the predictor variables, and the degree of nickel extraction as the response have been considered. To model the process, the multiple linear regression （MLR） and response surface method （RSM）, together with the two-level and four-factor full factorial central composite design （CCD） plan, were used. The proposed re- gression models have not been proven adequate. Therefore, the artificial neural network （ANN） approach with the same experimental plan was used in order to reduce operational costs, give a better modeling accuracy, and provide a more successful process optimization. The model is based on the multi-layer neural networks with the back-propagation （BP） learning algorithm and the bipolar sigmoid activation function.

摘要：The measurement of droplet velocities in Diesel sprays close to the nozzle is important because of the complexity of in-nozzle flow, spray break-up and evaporation. However, the measurement of droplet velocities in the dense region of Diesel sprays is very difficult or impossible by means of widely used laser diagnostic techniques, in particular under engine-like high-pressure and high-temperature conditions. The limitations of phase Doppler anemometry （PDA） and particle image velocimetry （PIV） prevent the application to the ultra-dense region of the spray. It was demonstrated that these problems can be greatly reduced by the laser flow tagging （LFT） technique. It was also demonstrated recently that LFT measurements can be conducted in clustered Diesel jets with improved spatial resolution and increased number of simultaneous measurements in the near-nozzle region. In the present work, the nozzle design, the temperature and pressure of the ambient air, and the fuel rail pressure are varied, in order to investigate the influence on the near-nozzle jet velocity and the underlying physical mechanisms.

摘要：要做到有效的网片修补是困难的。在过去的50年中,疝修补技术有了长足的进步,但仍然需要一些新的观念和方法来巩固疝修补术已经取得的成绩。在欧洲疝学会第30次国际大会上,疝修补术及网片试验评估领域的9名专家共同参加了一次圆桌会议,讨论当今疝修补术中亟待解决的问题;内容包括"理想"网片的定义及"理想"的网片材料。讨论的其他内容还包括轻量型网片的特点,网片替代物,外科医生在疝修补术中的作用,当今疝修补术中亟待解决的问题,以及最佳的动物试验模型。尽管人们对于理想网片的构成还没有定论,但对其重要的特点却有了更深的理解。希望这些建议可以促进疝治疗的发展,并催生出最为有效的疝修补网片材料。

摘要：现代机床结构中使用材料的种类非常广泛,从钢材、铸铁到纤维增强复合材料都有使用,还有采用多种材料组合和混合结构的情况,此外融合了传感器和执行器功能的创新智能材料使得功能集成结构得以实现。因此材料的设计和应用反映了关于复杂布局以及机架和部件优化各个方面的自由度。本文介绍了目前机床结构中应用的技术上最先进的材料,评论了相应的科学文献资料,概述并深入探讨了材料的选择以及高性能、高精度、高效率机床的开发。