Development and control of a new AUV platform

This paper presents an architecture of a newly developed autonomous underwater vehicle (AUV) platform, named KAUV-1, which is designed as a torpedo with very light weight and small size, suitable for use in marine exploration and monitoring. The KAUV-1 has a unique ducted propeller located at the aft end with yawing actuation acting as a rudder. For depth motion, the KAUV-1 is designed to have a mass shifter mechanism inside to change the vehicle center of gravity and to control its pitch angle and depth motion. The paper also presents an analysis on the equations of motion of the KAUV-1 with mass shifter mechanism and a new depth control strategy for the KAUV-1. The feasibility of the proposed control strategy is validated through simulation and experiment of performance of the vehicle.     

Micromechanical properties on the surface of PVC/SBR blends spatially resolved by a nanoindentation technique

The microhardness and micromodulus on the surface of poly(vinyl chloride) (PVC)/styrene‐butadiene rubber (SBR) blends were determined using a nanoindenter. A flat surface was obtained by microtoming the sample at ?100°C in liquid nitrogen. Dozens of indents along a line with a spatial interval of 0.5 μm were performed. From the loading and unloading curves of each indentation, the stiffnesses of the unloading curve and the contact area between the sample and the indenter were evaluated, and the local modulus and hardness were calculated. Profiles of the local hardness and modulus were obtained from the lines of indents. Pure PVC and a miscible PVC/acrylonitrile‐butadiene rubber (NBR) (40/10) blend showed constant modulus and hardness values. In the case of an immiscible PVC/SBR (50/50) blend, which has a morphology of elongated PVC droplets in the SBR matrix, the hardness and modulus profiles showed regions of the different phases. At the interface between the SBR and PVC phases, a step change in the modulus and hardness profiles was observed. The force required to deform the material at the same displacement increased systematically across the interface from the SBR to the PVC phase because of the increasing contribution of the PVC phase. Polym. Eng. Sci. 44:609–614, 2004. © 2004 Society of Plastics Engineers.     

Interfacial interaction in AI(OH)3/polypropylene composites modified by insitu‐functionalized polypropylene

To investigate the interfacial interaction of AI(OH)₃/polypropylene (PP) composites modified by in situ‐functionalized polypropylene (FPP), AI(OH)₃/polypropylene (PP) composites containing a low AI(OH)₃ content, modified by in situ‐grafted acrylic acid, were prepared by a one‐step melt‐extrusion process. The effect of in situ FPP on the crystallization and melting behavior, crystalline morphology of the composites, and interfacial interaction between the filler and PP was investigated. The crystallization and melting behavior and crystalline morphology of PP in the composites depended upon the interfacial physical [heterogeneous nucleation of AI(OH)₃; cocrystallization and compabilitization of PP with in situ FPP] and the interfacial chemical interaction between both the components in the composites. FTIR results indicated that there exists a chemical reaction between AI(OH)₃ and in situ FPP. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 110–120, 2002; DOI 10.1002/app.10270     

由铁醇盐配合物制备纳米Fe_2O_3

50℃时,在无隔膜电解槽中采用电化学溶解铁金属8 h,制备了铁配合物Fe(OEt)2(acac)[acac-为乙酰丙酮基],通过红外光谱、拉曼光谱和核磁共振对配合物进行了表征.采用含Fe(OEt)2(acac)的电解液直接水解、干燥制备干凝胶,然后在450℃煅烧2 h,得到纳米Fe2O3粉体.通过透射电子显微镜(TEM)和X射线粉末衍射(XRD)对纳米Fe2O3进行表征.实验表明:前驱体中含有acac基团,可以很好地阻止水解与煅烧过程中发生团聚;所得干凝胶粒径在10 nm左右,纯度较高的纳米Fe2O3粉体粒径在20~30 nm.     

阻燃性有机硅高分子材料的研究进展

综述了国内外在阻燃性有机硅高分子材料的制备、性能及应用等方面的研究进展，介绍了有机硅高分子材料的燃烧历程、常用阻燃剂及其阻燃机理，并对阻燃性有机硅高分子材料的研究发展前景进行了展望。     

Mechanical properties of Mg(OH)2/polypropylene composites modified by functionalized polypropylene

Modified Mg(OH)₂/polypropylene (PP) composites were prepared by the addition of functionalized polypropylene (FPP); and acrylic acid (AA) and by the formation of in situ FPP. The effects of the addition of FPP and AA and the formation of in situ FPP on the mechanical properties of Mg(OH)₂/PP composites were investigated. Experimental results indicated that the addition of Mg(OH)₂ markedly reduced the mechanical properties of PP. The extent of reduction in notch impact strength of PP was higher than that in flexural strength and tensile strength. However, tensile modulus and flexural modulus increased with increased Mg(OH)₂ content. The addition of FPP facilitated the improvement in the flexural strength and tensile strength of Mg(OH)₂/PP composites. The higher the Mg(OH)₂ content was, the more significant the effect of FPP was. The incorporation of AA resulted in further increased mechanical properties, in particular the flexural strength, tensile strength, and notch impact strength of Mg(OH)₂/PP composites containing high levels of Mg(OH)₂. It not only improved mechanical properties but also increased the flame retardance of Mg(OH)₂/PP composites. Although the mechanical properties of composites modified by the formation of in situ FPP were lower than those of composites modified by only the addition of AA in the absence of diamylperoxide, the mechanical properties did not decline with increased Mg(OH)₂ content. Moreover, the mechanical properties increased with increasing AA content. The addition of an oxidation resistant did not influence the mechanical properties of the modified Mg(OH)₂/PP composites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2139–2147, 2003     

Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren

Background  

Parents of six children are facing a trial on charges of aggravated manslaughter in the care a 5 1/2 month old infant who died suddenly and neglect of their four older children for causing them to be malnourished by feeding them all an exclusively raw foods vegan diet. Both parents declined plea bargains and plan to defend themselves in court.     

半芳香族耐高温尼龙PA6T/6I基LDS功能材料制备及性能

采用半芳香族耐高温尼龙聚对苯二甲酸/间苯二甲酸己二胺(PA6T/6I)为树脂基体,铜铬氧化物为激光镭射助剂,制备了PA6T/6I基的激光直接成型(LDS)功能材料。采用扫描电子显微镜对激光镭射助剂分散状态及LDS功能材料模塑器件的表面形貌能进行了表征,使用热失重分析仪、差示扫描量热仪对LDS功能材料的热失重行为、熔融结晶性能进行了表征,研究了激光镭射助剂添加量对LDS功能材料的力学性能、热稳定性、化学镀性能的影响,同时研究了PA6T/6I熔融结晶性能和注塑模具温度对于模塑器件表面、外观的影响。结果表明,偶联剂的添加有利于改善激光镭射助剂在PA6T/6I树脂基体中的分散,其中环氧类的偶联剂KBM–403处理后的LDS镭射助剂分散效果最佳。激光镭射助剂添加量的增加,会造成LDS功能材料拉伸强度、弯曲强度、冲击强度及初始分解温度降低。激光镭射助剂添加量在8%时,预镀铜上镀时间和镀层覆盖时间最短,化学镀效果最佳。当注塑模具温度为175℃时,玻纤增强PA6T/6I基LDS功能材料模塑器件的外观最佳。     

特征学习的单幅图像去雾算法

目的 雾霾天气使图像降质,严重影响军事、交通和安全监控等领域信息系统的正常运作,因此图像去雾具有重要研究意义。目前主流的单幅图像去雾算法主要利用各种与雾相关的颜色特征实现,但不同的颜色先验知识往往存在各自的场景局限性。为提高图像去雾的普适性,提出一种特征学习的单幅图像去雾方法。方法 首先通过稀疏自动编码机对有雾图像进行多尺度的纹理结构特征提取,同时抽取各种与雾相关的颜色特征。然后采用多层神经网络进行样本训练,得到雾天条件下纹理结构特征及颜色特征与场景深度间的映射关系,并估算出有雾图像的场景深度图。最后结合大气散射模型,根据场景深度图复原无雾图像。结果 与主流去雾算法的结果定性对比,复原后的图像细节更清晰,颜色更自然。采用均方误差和结构相似度定量评价各算法去雾结果与真实无雾图像的相似度,本文算法结果与真实无雾场景间的相似度最高,达到99.9%。结论 对实验结果的定性及定量分析表明,本文算法能有效获取有雾图像的场景深度,复原出视觉效果理想的无雾图像,且具有很好的场景普适性。     

高级氧化-IC-曝气工艺处理克林霉素生产废水实例

某药业股份有限公司克林霉素生产废水采用高级氧化-IC-曝气工艺处理,重点介绍了工程的调试启动。工程运行结果表明,出水水质稳定,COD为112mg/L,BOD5为23mg/L,SS为48mg/L,NH3-N为37.1mg/L,TN为49.6mg/L,硫化物为0.72mg/L,急性毒性(以HgCl2毒性当量计)为0.05mg/L,pH为8.22,处理后出水毒性和有机物浓度都大大降低,各项水质指标符合《化学合成类制药工业水污染物排放标准》(GB 21904-2008)的要求。