金矿矿源层和含金建造刍议

在矿源层评价中,相对于岩石中的金丰度,金的赋存状态具有更重要的意义,因此在工作中应恢复岩石的原始含金性,并计算区域金丰度值.本文还讨论了含金建造的概念、分布和评价准则等问题.     

Sn及其氧化物超微粉的制备与测试

本文采用气体蒸发法制备出粒度不到５ｎｍ的Ｓｎ及其氧化物的超微粉。利用热重，差热分析和Ｘ射线衍射谱等测试方法研究了热处理制度对其粒度，成份和气敏特性的影响，发现了ＳｎＯ_２正交相的存在。     

Inorganic/Organic Double‐Network Gels Containing Ionic Liquids

Highly robust ion gels, termed double‐network (DN) ion gels, composed of inorganic/organic interpenetrating networks and a large amount of ionic liquids (ILs), are fabricated. The DN ion gels with an 80 wt% IL content show extraordinarily high mechanical strength: more than 28 MPa of compressive fracture stress. In the DN ion gel preparation, a brittle inorganic network of physically bonded silica nanoparticles and a ductile organic network of polydimethylacrylamide (PDMAAm) are formed in the IL. Because of the different reaction mechanisms of the inorganic/organic networks, the DN ion gels can be formed by an easy and free‐shapeable one‐pot synthesis. They can be prepared in a controllable manner by manipulating the formation order of the inorganic and organic networks via not only multistep but also single‐step processes. When silica particles form a network prior to the PDMAAm network formation, DN ion gels can be prepared. The brittle silica particle network in the DN ion gel, serving as sacrificial bonds, easily ruptures under loading to dissipate energy, while the ductile PDMAAm network maintains the shape of the material by the rubber elasticity. Given the reversible physical bonding between the silica particles, the DN ion gels exhibit a significant degree of self‐recovery by annealing.     

Amyloid Formation in Nanoliter Droplets

Processes that monitor the nucleation of amyloids and characterize the formation of amyloid fibrils are vital to medicine and pharmacology. In this study, we observe the nucleation and formation of lysozyme amyloid fibrils using a facile microfluidic system to generate nanoliter droplets that can control the flow rate and movement of monomer-in-oil emulsion droplets in a T-junction microchannel. Using a fluorescence assay, we monitor the nucleation and growth process of amyloids based on the volume of droplets. Using the microfluidic system, we demonstrate that the lag phase, which is vital to amyloid nucleation and growth, is reduced at a lower droplet volume. Furthermore, we report a peculiar phenomenon of high amyloid formation at the edge of a bullet-shaped droplet, which is likely due to the high local monomer concentration. Moreover, we discovered that amyloid fibrils synthesized in the nanoliter droplets are shorter and thicker than fibrils synthesized from a bulk solution via the conventional heating method. Herein, a facile procedure to observe and characterize the nucleation and growth of amyloid fibrils using nanoliter droplets is presented, which is beneficial for investigating new features of amyloid fibril formation as an unconventional synthetic method for amyloid fibrils.     

Classification and prediction of burr formation in micro drilling of ductile metals

In the micro drilling of precision miniature holes, the formation of exit burrs is a topic of interest, especially for ductile materials. Because such burrs are difficult to remove, it is important to be able to predict various burr types and to employ burr minimisation schemes that consider burrs’ micro-scale characteristics. In the present work, an artificial neural network (ANN) was used to predict the formation of burrs in the micro drilling of copper and brass, along with burr formation/optimisation analysis specialised for micro drills. The influence of cutting conditions, including cutting speed, feed and drill diameter, upon exit micro burr characteristics such as burr size and type was observed, analysed and classified. Based on the results, an empirical equation to predict micro burr height is proposed herein. The classification results were compared with conventional burr cases using burr control charts. Then, micro burr types were predicted by means of an ANN, using the influential parameters as input vectors. The usefulness of the proposed scheme was demonstrated by comparing the experimental and prediction/analysis results.     

Effects of color display, color name, color formation and color alignment on the screen layout usability of customized product color combinations

This study investigated the effects of screen layout on the usability of a large number of color combination options for customized product. Using an L₁₈ orthogonal array, 18 interfaces were designed around four factors: color display, color name, color formation and alignment. Participants completed a color combination search task and a questionnaire concerning their satisfaction with the interfaces.Based on the search time and user satisfaction, the display of color samples by modular sections (itemized color chips) was found to be the optimal method of color selection. This arrangement reduced the number of combinations of color samples displayed on the screen and allowed efficient navigation of a large palette of color combinations. Vertical alignment aided the product color discrimination and reduced the search time. Users viewed various product color combinations directly with or without the aid of color names.

Relevance to industry

Because of the considerable observed reductions in search time and the superior reported degrees of satisfaction associated with the tested configurations for customized product color combination, the findings of this study have important ramifications for consumers and manufacturers of products as diverse as sofas, curtains, clothing, athletic shoes, cars, mobile phones and the other customized products.     

应用控制系统设计工具箱PIMCSD求解卫星编队重构问题

利用线性时变系统终端约束最优控制方法,为椭圆轨道卫星编队的队形重构控制问题设计了均衡耗能最优控制器.由于描述椭圆轨道卫星编队相对运动的Lawden方程是时变方程,给卫星编队重构的最优控制器设计带来一定的困难.利用基于精细积分算法的控制系统设计工具箱-PIMCSD进行系统设计,求解卫星编队重构所需的时变最优反馈控制律和前馈控制律,最后给出了由三颗卫星组成的编队队形重构控制仿真计算结果.     

LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connect- ing rod type low speed high torque (LSHT) hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by com- puter simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coef- ficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.