Design,characterization and control of SMA springs-based multi-modal tactile display device for biomedical applications

Tactile display is recently attracting much attention in the field of human–computer interaction. There is a strong need for such a device especially for applications in which the touch feeling is lost, such as surgeons who are willing to feel the tissue hardness during laparoscopic surgeries. In this paper, a novel multi-modal tactile display device which can display both surface shape and stiffness of an object is introduced. The conceptual design is built upon using two springs, made of Shape Memory Alloys (SMA), for displaying shape and stiffness. The design parameters of this device are selected based on the spatial resolution of human finger and the elasticity range of the soft tissue. The display device is simulated using Finite Element Method (FEM) to study the effect of design parameters on the resulting stiffness. Simulation results show that the device can display stiffness of an object independent of its shape display. The experimental setup is built and used for the characterization and control of the SMA springs. Experimental results show that the device can display a stiffness range of (35–110) N/m and elongation up to 5 mm.     

防渗帷幕在我国生活垃圾填埋场中的应用前景

从防渗角度出发，论述了在有条件的生活垃圾卫生填埋场的用防渗帷幕的可能性，并用实例证明了其技术上的可行性。从建设投资上分析，防渗帷幕大大低于水平人工防渗垫层，为我国生活垃圾卫生填埋场建设的防渗措施，提出了一条新思路。     

应用新一代萃取剂Cyanex272进行钴镍分离的研究

Ｃｙａｎｅｘ２７２是新一代在硫酸盐溶液中分离钴、镍的萃取剂。本文研究了各种因素对Ｃｙａｎｅｘ２７２分离钴、镍的影响,探寻了Ｃｙａｎｅｘ２７２在镍电解净液钴渣处理工艺和高冰镍精炼新工艺中的应用前景。     

轻质油裂解C_9馏份合成石油树脂

对轻质油裂解C_9馏份合成石油树脂的工艺进行了研究。采用自由基和阳离子两步聚合法使石油树脂总收率提高到60％以上。采用终止剂和过滤法脱除催化剂代替传统的碱洗、水洗法,避免了产生大量含氟废水所造成的环境污染问题。实验室和中间放大试验结果表明用此法生产的深色树脂具有良好的互溶性能,浅色树脂色相(Gardner)不高于8~#,软化点大于120℃。     

尾鳍的形状与运动参数对推进速度的影响

从推进速度的角度出发,实验研究了尾鳍摆动式水下推进器尾鳍的形状参数与运动参数对推进速度的影响,给出了实验结果,对尾鳍摆动式水下推进器的设计具有重要的意义。     

Silver Sulphide Formation During Thiosulphate Sensitization

Emulsions prepared with an inert gelatin have been sensitized with sodium thiosulphate labelled with radioactive ³⁵S. An analytical technique similar to that used by Frieser and Ranz¹ has been used to measure the amounts of silver sulphide formed. The breakdown of thiosulphate has been shown to follow first order reaction kinetics at a rate proportional to the free silver ion concentration in the emulsion to the power of 0.8.     

A Decomposition of Total Variation Depth for Understanding Functional Outliers

Abstract

There has been extensive work on data depth-based methods for robust multivariate data analysis. Recent developments have moved to infinite-dimensional objects, such as functional data. In this work, we propose a notion of depth, the total variation depth, for functional data, which has many desirable features and is well suited for outlier detection. The proposed depth is in the form of an integral of a univariate depth function. We show that the novel formation of the total variation depth leads to useful decomposition associated with shape and magnitude outlyingness of functional data. Compared to magnitude outliers, shape outliers are often masked among the rest of samples and more difficult to identify. We then further develop an effective procedure and visualization tools for detecting both types of outliers, while naturally accounting for the correlation in functional data. The outlier detection performance is investigated through simulations under various outlier models. Finally, the proposed methodology is demonstrated using real datasets of curves, images, and video frames.     

Microstructure and Transformation Behavior of in-situ Shape Memory Alloys by Selective Laser Melting Ti-Ni Mixed Powder

The selective laser melting(SLM) of Ti-Ni mixed powder with atomic ratio of 1:1 was performed in the present work in order to elaborate shape memory alloy(SMA).The martensite phase of Ti-Ni alloy can be found by X-ray diffraction(XRD) analysis under temperature field,moreover,the Ti2Ni phase at a high scanning velocity.The crystalline phase images also show that the synthesized Ti-Ni alloy possessed a refined martensite microstructure.In order to evaluate the mechanical properties,the microhardness and porosity were measured.The microhardness is relatively high about 400HV0.2 with champ temperature.Besides,the porosity is quite low due to the excellent laser energy absorptivity and meltability of Ni element.The differential scanning calorimetry(DSC) analysis shows that the transformation temperature from austenite phase to martensite phase is relatively high and stable.     

屠宰场生鸡肉肠炎沙门氏菌的污染途径

目的：研究屠宰场生鸡肉肠炎沙门氏菌的主要污染途径。方法：以屠宰场生鸡肉样品为研究对象,在利用多聚酶链反应(PCR)检测肠炎沙门氏菌污染的基础上,通过流行病学的方法研究生鸡肉污染与肉鸡感染的关系。结果：屠宰场生鸡肉样品肠炎沙门氏菌污染阳性率为9.03%(26/288),样品污染与样品来源屠宰场间无统计学联系,但与养殖场的肉鸡感染肠炎沙门氏菌有联系;养殖场肉鸡感染肠炎沙门氏菌与生鸡肉污染有正的统计学联系(相对危险性=18.5);肉鸡实验性感染肠炎沙门氏菌后的带菌时间可达42d,排菌达56d 以上。结论：屠宰场生鸡肉肠炎沙门氏菌的污染途径主要为内源性污染。