基于内容的自适应插值滤波器在无损视频编码中的应用

为了解决高效率视频编码（high efficiency video coding,HEVC）帧间运动补偿中亚像素插值使用的固定插值滤波器无法自适应于视频序列内容所造成的预测精度下降的问题,针对HEVC无损压缩提出一种自适应插值滤波器方案.该方案通过极小化帧间预测误差得到自适应插值滤波器,对所有的帧间编码块通过自适应插值滤波器来获取亚像素预测像素块,自适应减少帧间预测误差,从而提升整体编码性能.将该方案应用于HEVC参考软件HM（HEVC test model）12.1中,实验结果表明,在不影响编解码端时间复杂度的情况下,所提出算法的压缩效率在low delay P和low delay B配置文件下分别比HEVC无损压缩效率平均提升1.32%和0.69%.

     

Microstructure,Magnetic Properties,and Thermal Stability of Bulk Anisotropic SmCo7/α-Fe(Co) + Nd2Fe14B/α-Fe Multiphase Nanohybrid Magnets

Journal of Superconductivity and Novel Magnetism - In this report, we have fabricated anisotropic bulk SmCo7/α-Fe(Co)?+?Nd2Fe14B/α-Fe multiphase nanohybrid magnets using...     

粉床型电子束3D打印纯钨及W-Nb合金的显微组织及开裂机制

采用粉床型电子束3D打印技术制备了纯钨及固溶强化型W-Nb合金,对两种钨基材料的显微组织和裂纹缺陷进行了分析。研究发现：二者均沿逐层累积的方向形成柱状晶,Nb元素的加入使柱状晶的平均尺寸由109.78μm降至25.10μm。纯钨并未发生明显的开裂现象,但是W-Nb合金内部存在少量沿晶界分布的微裂纹。从热应力累积和凝固过程两个方面分析了钨基材料开裂的原因,粉床型电子束3D打印过程包含了熔池的快速凝固-快速冷却-高温保温几个阶段,过程中纯钨及W-Nb合金均发生了回复与再结晶,使成形过程中累积的热应力得到一定的释放,缓解了热应力累积引起的开裂现象。W-Nb合金的开裂主要是由于凝固过程中液态金属无法短时间内在枝晶间进行充分流动补缩,形成大量沿晶界分布的纳米微缩孔,在微小的应力作用下就会造成合金沿晶界开裂。     

A mobile dual-arm manipulation robot system for stocking and disposing of items in a convenience store by using universal vacuum grippers for grasping items

ABSTRACT

A mobile dual-arm robot with universal vacuum grippers (UVG) for performing stocking and disposing tasks was developed. The robot grasps items in the tasks by using UVGs whose surface adapts to the various shapes of the items. A selection algorithm that determines whether the robot should use one or both manipulators to arrange an item was also developed. A ‘reachable-grasp pose’ is defined as a pose in which the robot’s UVG can easily place an item with a target attitude if it grasps the item. By using the selection algorithm, the robot re-grasps the item by adopting the reachable-grasp pose if the two manipulators do not collide when one is in the current grasp pose and the other is in the reachable-grasp pose. The robot system won the third prize of the Future Convenience Store Challenge 2018. In experiments on stocking and disposing tasks, the robot system achieved success rates of 100% for the stocking task and 80% for the disposing task. We believe that the results of this study will help researchers to develop a robot system for not only the stocking and disposing tasks but also other tasks in convenience stores (like customer interaction).     

Numerical study on particle deposition in rough channels with different structure parameters of rough elements

This paper presents a study of the characteristics of particle deposition in rib-roughened channels. The gas-particle flow was numerically investigated by Reynolds stress model (RSM) with the discrete particle model (DPM). The particle deposition velocity and deposition ratio at different positions were numerically investigated in a channel where the relative roughness factor, e/D, were between 0.02 and 0.1, and the ratios of rough-element spacing to its height, p/e, were between 7 and 20. It is found that the eddy structures behind the rough-elements are changed by the increase of e/D. The windward surfaces are the main deposition regions and the cavities between the rough-elements are the secondary deposition regions. e/D contributes more to the increase of particle deposition velocity than p/e.     

圆度误差评定的计算机实现方法

用最小二乘圆法研究圆度误差评定问题．提出一种圆度误差评定的计算机算法．在微机上用Ｃ语言实现确定最小二乘圆圆心,并以此为评定基准计算轮廓曲线上到该圆心的最大和最小半径之差即为圆度误差,并给出了实例     

增感染料与卤化银微晶之间的作用及其聚集态的研究

本文研究了光谱增感染料的结构对立方体卤化银乳剂的感光性能的影响,并利用反射光谱和彩色分析荧光电镜研究了染料在卤化银微晶上的聚集态和Ｊ－聚集体的相对尺寸,通过测定乳剂离子电导率研究了染料的结构对乳剂离子电导率的影响。     

窖泥酯化菌的富集筛选及其生长条件研究

以优质老窖泥为研究对象,厌氧条件下富集酯化菌,并对富集条件进行优化。通过传统培养分离法及顶空固相萃取-气相色谱-质谱（HS-SPME-GC-MS）法从优化富集液中筛选酯化菌,通过形态观察、生理生化试验及分子生物学技术对其进行鉴定,并研究其生长条件。结果表明,窖泥富集液培养20 d并富集2次有利于酯化菌的富集,从优化富集液中共筛选出3株产己酸乙酯和丁酸乙酯的厌氧梭菌。经鉴定,菌株Y1、Y2、Y3分别为拜氏梭菌（Clostridium beijerinckii）、Clostridium guangxiense、Clostridium sartagoforme,其中,菌株Y1的最佳生长温度为30 ℃、最适生长pH值为5;菌株Y2的最佳生长温度为34 ℃、最适生长pH值为7;菌株Y3的最佳生长温度为37 ℃,最适生长pH值为5,且3株菌株的最高耐乙醇体积分数达20%。     

稀土含量对MmNi_5基储氢合金性能的影响

测试了ＭｍｘＮｉ３．８Ｃｏ０．６Ｍｎ０．５５Ｔｉ０．０５（ｘ＝１．０５,１,０．９５）合金的充放电特性及循环寿命。当ｘ＝１．０５时,合金有较高的放电容量而循环寿命略有降低,这主要归因于稀土元素有较好的吸氢特性且易在晶界处偏析,形成ＭｍＮｉ相。当ｘ＝０．９５时,合金的放电容量及循环寿命显著降低,这是由于合金中的Ｍｎ向晶界处偏析,且极易溶于６ＭＫＯＨ中,破坏了合金表面,降低了放电容量和循环寿命。     

酿酒酵母醇酰基转移酶的研究进展

酵母发酵产生酯类化合物是白酒发酵过程中的重要产香成分之一。在白酒多年的发展过程中,其香味物质的成分一直不能为人们标准化,不能实现更好的机械化智能化的生产,因此研究酵母产酯途径已成为人们现在热议的话题。该文综述了酿酒酵母酰基酯合成途径中的关键酶的酶学性质、晶体结构与分子催化机制,并展望了其在提升白酒品质和推进白酒的标准化进程的潜力与价值。