Using rotary contact method for 5-axis convex sculptured surfaces machining

The 5-axis tool positioning strategy named rotary contact method (RCM) for sculptured surfaces machining has been developed in our previous paper (Wengang Fan et al., J Manuf Sci E-T ASME 134(2):021004.1-021004.6, 2012). The RCM finds the optimal tool positions by rotating the tool backward based on the offset surface instead of the design surface, and can generate big machined strip width without gouging. However, the RCM only deals with concave sculptured surfaces machining well at present, and the special property of convex sculptured surfaces machining has not been fully exploited. To resolve this problem, the general convex sculptured surfaces machining using the RCM is implemented in this paper. Firstly, the tool position error distribution for different tool feed directions is deeply investigated. It is concluded that the best tool feed direction is collinear with the maximum direction of curvature, which is completely opposite to the case for concave sculptured surfaces machining. Then the relationship between the key parameters in the RCM and the tool position error distribution as well as the tool path generation is totally discussed. Finally, machining simulation and cutting experiment of a convex sculptured surface example are performed. The results show that the RCM can apparently raise the efficiency of manufacturing process by contrast with the algorithm in the software UG for convex sculptured surfaces machining.     

Oversample Reconstruction Based on a Strong Inter-Diagonal Matrix for an Optical Microscanning Thermal Microscope Imaging System

Based on a strong inter-diagonal matrix and Taylor series expansions,an oversample reconstruction method was proposed to calibrate the optical micro-scanning error.The technique can obtain regular 2 × 2 microscanning undersampling images from the real irregular undersampling images,and can then obtain a high spatial oversample resolution image.Simulations and experiments show that the proposed technique can reduce optical micro-scanning error and improve the system's spatial resolution.The algorithm is simple,fast and has low computational complexity.It can also be applied to other electro-optical imaging systems to improve their spatial resolution and has a widespread application prospect.     

ADSP2101FEL－ICE开发系统

本文介绍了一种数字信号处理器（ＡＤＳＰ－２１０１）的开发系统──ＡＤＳＰ２１０ＩＦＥＬ－ＩＣＥ。描述了它的基本功能和设计思想。     

加工工艺对香榧籽油中挥发性物质组成的影响

旨在为风味香榧籽油的开发提供理论支持,考察了不同加工工艺（烘烤温度和压榨工艺）对香榧籽油理化指标的影响,并采用电子鼻、顶空固相微萃取-气质联用（HS-SPME-GC-MS/MS）等技术研究不同烘烤温度（140、150、160、170、180 ℃）和压榨工艺（螺杆压榨和液压压榨）对香榧籽油中挥发性物质组成的影响。结果表明：烘烤温度和压榨工艺对香榧籽油酸值影响较小,随烘烤温度的升高,螺杆压榨和液压压榨对香榧籽油过氧化值的影响不同,但不同烘烤温度和压榨工艺条件下制取的香榧籽油酸值和过氧化值均符合GB 2716—2018中的要求;电子鼻分析表明氮氧化合物、硫化物、芳香成分、甲基类物质对香榧籽油风味的影响较大;液压压榨和螺杆压榨香榧籽油风味最浓郁的烘烤温度分别为140 ℃和170 ℃;香榧籽油中共检出挥发性物质7类42种,其中萜烯类物质占主导;不同温度烘烤后液压压榨制取的香榧籽油中共有5种挥发性物质的相对含量发生显著变化,而螺杆压榨制取的香榧籽油中有18种挥发性物质的相对含量发生显著变化,柏木脑和香芹酮为两种压榨工艺共有的相对含量发生显著变化的物质。综上,压榨工艺会影响香榧籽油达到浓郁风味所需要的热风烘烤条件,且螺杆压榨相较于液压压榨,其风味物质种类变化更加丰富。     

Effects of Exosomes Derived from Adipose-Derived Mesenchymal Stem Cells on Pyroptosis and Regeneration of Injured Liver

Although accumulating evidence indicates that exosomes have a positive therapeutic effect on hepatic ischemia–reperfusion injury (HIRI), studies focusing on the alleviation of liver injury by exosomes derived from adipose-derived mesenchymal stem cells (ADSCs-Exo) based on the inhibition of cell pyroptosis have not yet been reported. Exosomes contain different kinds of biologically active substances such as proteins, lipids, mRNAs, miRNAs, and signaling molecules. These molecules are widely involved in cell–cell communication, cell signal transmission, proliferation, migration, and apoptosis. Therefore, we investigated the positive effects exerted by ADSCs-Exo after hepatic ischemia–reperfusion with partial resection injury in rats. In this study, we found that the post-operative tail vein injection of ADSCs-Exo could effectively inhibit the expression of pyroptosis-related factors such as NLRP3, ASC, caspase-1, and GSDMD-N, and promote the expression of regeneration-related factors such as Cyclin D1 and VEGF. Moreover, we found that the above cellular activities were associated with the NF-κB and Wnt/β-catenin signaling pathways. According to the results, ADSCs and ADSCs-Exo can reduce pyroptosis in the injured liver and promote the expression of those factors related to liver regeneration, while they can inhibit the NF-κB pathway and activate the Wnt/β-catenin pathway. However, although adipose-derived mesenchymal stem cell (ADSC) transplantation can reduce liver injury, it leads to a significant increase in the pyroptosis-related protein GSDMD-N expression. In conclusion, our study shows that ADSCs-Exo has unique advantages and significance as a cell-free therapy to replace stem cells and still has a broad research prospect in the clinical diagnosis and treatment of liver injuries.     

惯性/卫星导航系统实际导航性能评估算法

针对惯性/卫星组合导航进行实际导航性能(Actual Navigation Performance,ANP)评估,是保证飞机所需导航性能(Required Navigation Performance,RNP)及航空运行安全的关键.提出了惯性/卫星组合导航系统实际导航性能评估算法,从卡尔曼滤波器位置协方差矩阵开展分析,...     

大容积薄壁冰箱风道及箱体流场分析

目前在大容积间冷式冰箱研发设计中,由于薄壁技术和传统结构的技术限制,缺乏进一步提升冰箱容积率的方法.针对这一问题,基于某原型机,设计了横置蒸发器及其配套风道的新型结构.对横置蒸发器冰箱进行CFD仿真,分析横置蒸发器风道和箱体的内部流场特性演化规律.发现风扇同转速下,横置蒸发器冰箱相比较竖置蒸发器的冰箱左右两侧进出口风量...     

轮廓测量系统中摄像机的光学畸变校正方法

在基于机器视觉的轮廓测量系统中,由于摄像机的透镜透光率不均,成像中存在光学畸变,对测量精度造成影响。为了对光学畸变进行校正,论文首先建立畸变数学模型,然后使用系统测量正方形标定板得到存在畸变的轮廓数据,根据存在畸变的轮廓数据的几何特征和直线约束条件使用LM优化算法完成对畸变模型中参数的标定。通过实验多次标定同一套轮廓测量系统,将标定结果与已有方法进行比较。实验结果表明,相较于已有算法,该论文所提方法多次标定的结果标准差更小,说明该论文所提方法具有更好的鲁棒性。     

蒸制鲟鱼肉特征性滋味组分的鉴定

为明确传统热加工鲟鱼肉特征性滋味组分,对蒸制鲟鱼肉中游离氨基酸、核苷酸、有机酸、甜菜碱及无机离子等滋味组分进行定量分析,并结合滋味活性值、滋味组分减缺、添加及重组实验探究蒸制鲟鱼肉的关键味觉化合物。结果表明：蒸制16 min鲟鱼肉的关键味觉化合物为甘氨酸、谷氨酸、丙氨酸、5’-一磷酸腺苷、5’-一磷酸肌苷、乳酸、琥珀酸、K＋、Na＋和Cl－;将10 种关键味觉化合物按其天然含量溶解在超纯水中制备简化重组液,简化重组液能够较为完整地复制完全重组液的味道,但与天然提取液相比,在鲜味上仍有所欠缺。     

新一代仿真技术框架HLA中基于组播通信的数据过滤机制

高级体系结构ＨＬＡ是美国国防部提出的新一代仿真技术框架,其目的是解决各类型仿真应用之间的互操作和可重用,它代表着仿真技术发展的趋势。未来的分布交互仿真建立在因特网环境下,受系统资源的限制,系统可扩缩性是分布交互仿真面临的一个主要问题。文中介绍了分布交互仿真发展简史,以及ＨＬＡ 提出的背景及其特点,文章着重讨论了组播通信机制在分布交互仿真中的应用,及ＨＬＡ 框架下采用基于组播通信的过滤机制实现系统可扩缩性的解决途径