Revealing the relationships between alloy structure,composition and plastic deformation in a ternary alloy system by a combinatorial approach

A high-throughput approach based on magnetron co-sputtering of alloy libraries is employed to inves-tigate mechanical properties of crystalline and amorphous alloys in a ternary palladium(Pd)-tungsten(W)-silicon(Si)system with the aim to reveal the difference in plastic deformation response and extract the relevant structure-property relationships of the alloys in the system.It was found that in contrast to crystalline alloys,the amorphous ones,i.e.,metallic glasses,exhibited a much smaller fluctuation range in the plasticity parameters(Er2/H and Wp/Wt),indicating a significant difference in the plastic deformation mechanism controlling the mechanical properties for the respective alloys.We propose that the inho-mogeneous deformation of amorphous alloys localized in thin shear bands is responsible for the weaker compositional dependence of both plasticity parameters,while dislocation gliding in crystalline materials is significantly more dependent on the exact structure,thus resulting in a larger scattering range.Based on the representative efficient cluster packing model,a set of composition-dependent atomic structural models is proposed to figure out the structure-property relationships of amorphous alloys in Pd-W-Si alloy system.     

复杂造型墙地面的瓷砖镶贴施工

北京康乐宫嬉水乐园的墙体有不同的曲率半径,地面与池底有不同标高与斜度,瓷砖饰面层极不规则。施工时根据功能需要与艺术效果统一的原则,选择了10种不同规格的瓷砖。由于采取有效的防水措施,确保了水池不渗漏。排砖采用“通缝”与“骑马缝”两种方法,以适应不同形状、不同功能要求的地面。文中对主要部位(如水池底部、池壁、池边、人工海滩、异形部位等) 瓷砖的排列方法作了详细叙述。     

腐植酸诱导人早幼粒白血病HL-60细胞凋亡

试验采用人早幼粒白血病HL-60细胞,主要通过细胞活性丧失,染色质凝聚、核小体间DNA断裂等凋亡特征,研究了腐植酸诱导细胞凋亡的效应,观察了不同时间不同剂量(50～400 μg/mL)腐植酸对细胞凋亡的影响.腐植酸诱导HL-60细胞凋亡主要与线粒体内细胞色素c的释放有关,并证明伴随着Caspase-3(天冬氨酸特异性半...     

MEASUREMENT OF ANODIC OVERVOLTAGE BY AMODIFIED CURRENT INTERRUPTION METHOD IN CRYOLITE-ALUMINA MELTS

１ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｈｅｅｌｅｃｔｒｏｌｙｔｉｃｐｒｏｄｕｃｔｉｏｎｏｆａｌｕｍｉｎｉｕｍ，ｔｈｅｃｅｌｃｏｎｓｉｓｔｓｏｆａｃａｒｂｏｎａｎｏｄｅａｎｄａｎａｌｕｍｉｎｉｕｍｍｅｔａｌｃａｔｈｏｄｅ．Ｔｈｅｄｏｍｉｎａｎｔｐｏｔｅｎｔ...     

从KCC铜离子处理法的尾矿中浮选细粒碳酸锰

引言锰结核于1873—76年首先为查伦杰(H.M.S.challenger)探险队所发现,此后就吸引着海洋学家及自然资源工程师们的兴     

Burr Contour Recognition and Coordinates Sequence Real-Time Generation for Robotic Deburring Efficiency Optimization

毛刺轮廓识别和坐标顺序实时生成下的机器人去毛刺效率优化

熊仁涛¹,赖增亮¹,管贻生¹,杨宇峰²,蔡传武²

（1. 广东工业大学 机电工程学院,广州 510006;

2. 佛山博文机器人自动化科技有限公司,佛山 528237）

创新点说明：

1） 提出一种基于视觉的毛刺轮廓识别方法;

2） 将毛刺轮廓坐标按照标准工件闭环轮廓去毛刺加工顺序实时生成;

3） 通过调整去毛刺速度提高机器人去毛刺的效率。

研究目的：

提供一种高精度和高效率的机器人自动化去毛刺技术和装备,解决现代机械制造行业中存在的加工精度差和去毛刺效率低的问题,包括但不限于机器人去毛刺、抛光打磨、焊缝处理、喷涂等机器人自动化作业。

研究方法：

1）基于局部可变形模板匹配算法,将标准工件轮廓与待加工工件轮廓进行配准;

2）计算两轮廓之间逐点像素距离,基于设定的距离阈值将毛刺大小划分为不同的量级;

3） 将毛刺轮廓坐标映射到标准工件轮廓中,实时生成机器人去毛刺闭环加工路径顺序;

4） 基于毛刺大小量化信息,实时调整机器人去毛刺的速度。

研究结果：

1）针对具有随机形变的工件,基于局部可变形模板匹配算法可以获得高的轮廓匹配度;

2） 在X和Y方向上,对毛刺轮廓坐标进行排序,可以生成与标准工件轮廓去毛刺路径一致的加工顺序;

3） 基于毛刺大小量化信息,可以实时调整机器人去毛刺的速度。

结 论：

基于视觉的提高机器人去毛刺效率的方法,相比传统离线编程去毛刺,去毛刺效率提高了13.53%。

关键词：机器人去毛刺;装配精度;轮廓识别;模板匹配;去毛刺效率

     

Comprehensive assessment on dynamic roof instability under fractured rock mass conditions in the excavation disturbed zone

The damage process of fractured rock mass showed that the fracture in rocks induced roof collapse in Yangchangwan Coal Mine,China.The rock mass was particularly weak and fractured.There occurred 6 large-scale dynamical roof falls in the excavation disturbed zone (EDZ) with the collapsing volume of 216 m3.First,the field detailed geological environment,regional seismic dy-namics,and dynamic instability of roadways were generally investigated.Second,the field multiple-index monitoring measurements for detecting the deep delamination of the roof,convergence deformation,bolt-cable load,acoustic emission (AE) characteristic pa-rameters,total AE events,AE energy-releasing rate,rock mass fracture,and damage were arranged.Finally,according to the time-space-strength relations,a quantitative assessment of the influence of rock-mass damage on the dynamic roof instability was accomplished.     

Modeling the effects of sodium chloride on degradation of chloramphenicol in aquaculture pond sediment

Sodium chloride was added to aquaculture pond sediment to determine effects of different salinities on degradation of chloramphenicol (CM). In this experiment, freshwater (0 ppt salinity) eel pond sediment slurries (10% w/v) were amended with sodium chloride to obtain salinities of 12, 24 and 36 ppt. There were no significant differences in sorption rate either between aerobic and anaerobic conditions or among various salinities. Degradation of CM fitted well to the decaying exponential curve. The degradation rates under anaerobic conditions were significantly greater than those under aerobic conditions. As salinity increased, the degradation rates decreased under both aerobic and anaerobic conditions. The differences in degradation rates either between aerobic and anaerobic conditions or among various salinities were attributed to the effects of microbial activities under different environments.     

Ultrasonication and the quality of human milk: variation of power and time of exposure

Donor human milk is pasteurized to prevent the potential risk of the transmission of pathogens to preterm infants. Currently, Holder pasteurization (human milk held at 62·5°C for 30 min) is used in most human milk banks, but has the disadvantage that it results in excessive inactivation of important bioactive components. Power-ultrasound (20-100 kHz) is an emerging technology for the preservation of foods and could be an alternative method for the treatment of human milk. The aim of this study was to investigate the effect of different ultrasound settings on the elimination of Escherichia coli and the retention of bile salt stimulated lipase (BSSL) activity. Ultrasonication with a constant power decreased Esch. coli viability exponentially over time until the processing temperature increased to sub-pasteurization level to between 51·4 and 58·5°C, then a log10 1·3 decrease was observed (P<0·05). BSSL activity decreased to 91% until a temperature of 51·4°C and then it decreased to 8% between 51·4 and 64·9°C. Ultrasonication with a constant energy and various power and exposure times showed the highest temperature (53·7°C) when treated with the longest exposure time and lowest ultrasound-power (276 s at 3·62 W) compared with 37·6°C for 39 s at 25·64 W. The findings predict that the viability of Esch. coli could be reduced by log10 5 with a minimal loss of activity of BSSL by applying 13·8 kJ of energy in 12 ml of human milk using high ultrasound power over a short exposure time to ensure that the temperature remains below the critical level for protein denaturation. Alternatively, the use of lower power settings such as the 26 W used in the present studies would require a cooling system to ensure the human milk BSSL was protected against temperature denaturation.