纳米材料的研究进展

总结了近几年来纳米材料的研究进展，着重从纳米材料的制备、微观结构、力学及热力学性能的研究情况作了一个概述，总结了有关纳米材料的几个研究热点以及分子动力学计算机模拟在纳米材料研究中的应用。最后并指出出几个急待研究的工作

A Study of De-noising Methods in Face Recognition System

人脸识别是近几年来非常受关注的研究课题之一,这一研究领域包括:图像处理、模式识别、计算机视觉、神经网络,心理学等多个交叉学科。人脸识别系统非常复杂,其中处理的对象都是人脸图像数据。从现实中获取的图像包含各种噪声信号,使图像数据和现实差距太大。为了快速有效的去除这些噪声信号,本文详细研究了各种去除噪声的方法和原理,通过试验以直观的方式研究几种去噪效果,指出各种方法的优缺点。提出了将小波去除噪声和特征提取相结合以及PCA在噪声去除和特征提取相结合的方法。Machine recognition of human face still and video im- ages is emerging an active research area including several disci- plines, such as: image processing, pattern recognition, computer vision, neural networks, psychology and so forth. The human face recognition system is complex which processes a large of image data. Obtained from reality environment, the images con- tain a lot of noise. In order to de- noise more effectively and quickly, several general de - noising methods and theories are carefully studied in the paper. Compared the methods through the experiences and got results, then, the advantage and disad- vantage of each method are pointed out. The novel methods are suggested, for example, combining wavelet de- noising with fea- ture extraction, combining de- noising with PCA.福建省自然基金(A0310005);; 国家留学回国人员基金资助(K13003

Human Face Image Edge Detection Methods and Application

如何确定人脸特征并对这些特征进行有效的提取是非常关键而且复杂的。人脸边缘和轮廓是人脸非常重要的特征。该文研究了边缘检测的原理和各种算法,通过试验验证各种检测方法在人脸图像中对边缘的检测效果,讨论选用在不同阈值下检测的边缘,以及影响检测效果的因素。最后通过实例研究了人脸边缘检测在人脸检测和识别中的具体应用。How to define and extract the feature of human face is a key and complicated problem. The edge and contour of human face is one of important feature. This paper studies the theory of edge detection and different kinds of arithmetical methods. The experiment results are used to confirm the different methods which are employed to test the edge detection results of the human face image. It discusses the consequence of detection when the threshold is varying and the possible factors, which makes the different results. Finally, it studies the application of the edge detection in human face detection and recognition.福建省自然科学基金资助项目(A0310005);; 国家留学回国人员基金资助项目(K13003

Retinoic acid receptor β is required for anti-activator protein-1 activity by retinoic acid in gastric cancer cells

Objective To investigate the role of retinoic acid receptor β (RARβ) in mediating inhibitory effect of all-trans retinoic acid (ATRA) on activator protein-1 (AP-1) activity in gastric cancer cells. Methods Transient transfection and chloramphenicol acetyltransferase (CAT) assay, Northern blot, gene transfection, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and anchorage-independent growth assay were used.Results Transient transfection of RARβ expression vector into MKN-45...theNationalOutstandingYouthScienceFoundationofChina (No 3982 5 5 0 2 )andtheNationalNaturalScienceFoundationofChina (No 39880 0 15

Effects of Nd element addition on microstructure and mechanical properties of Ti-6Al-4V-2Cr alloy

本试验采用冷等静压法及粉末冶金法制备钛合金,消除了成分偏析对合金性能的影响。在Ti-6Al-4V-2Cr中加入稀土Nd元素并进行热处理,运用光学; 显微镜、XRD和TEM对其组织和性能进行观察和分析。通过观察发现合金的组织为均匀的alpha +; beta相。运用XRD和TEM观察发现,晶界和晶内均有Nd_2O_3析出物,Nd_2O_3的出现细化了晶粒,提高了形核率,降低了晶粒尺寸。运用精; 密万能试验机进行了力学性能测试,当Nd元素含量为1%时,合金的综合力学性能最好,合金的抗拉强度提高了10.7%,伸长率提高了49.1%。The Ti-6Al-4V-2Cr-xNd alloys were prepared by the cold isostatic; pressing method and powder metallurgy with addition of Nd element,the; effect of composition segregation on properties of the titanium alloy; was eliminated,and microstructure and the properties of the alloy after; heat treatment were studied by means of optical microscope,XRD and TEM.; The results show that the microstructure of the Ti-6Al-4V-2Cr-xNd is; composed of homogeneous alpha + beta phase. Nd_2O_3 precipitates are; observed in the grain boundaries and in the grains by XRD and TEM,and it; can refine the grains,increase the nucleation rate and decrease the; grain size. The optimal mechanical properties of the alloy are obtained; when the Nd content is 1%,and the tensile strength and elongation of the; alloy increase by 10.7% and 49.1%,respectively.军工863项目; 国防973支持项

Effect of Retinoic Acid Receptor β in Growth Regulation of Gastric Cancer Cells

为探讨 RARβ受体介导全反式视黄酸 ( ATRA)抑制胃癌细胞生长的作用机理 ,用 Northern印迹测定 RARβ m RNA表达水平 ,脂质体介导的转染方法将含有 RARβ基因的表达载体转染MKN- 45细胞并稳定表达 ,MTT和软琼脂集落形成等实验测定细胞生长速率和生长状态 ,氯霉素乙酰转移酶活性 ( CAT)测定视黄酸应答元件βRARE的转录活性以及 AP- 1 ( activator protein- 1 )活性 .RARβ在 ATRA敏感细胞株 MGC80 - 3、BGC- 82 3和 SGC- 790 1中表达 ,而在 ATRA抗性细胞株 MKN- 45中不表达 .当 RARβ基因转染 MKN- 45细胞时 ,细胞变为 ATRA敏感 ,由此导致ATRA抑制 MKN- 45细胞生长和软琼脂集落形成 .ATRA可以加强诱导 MGC80 - 3、BGC- 82 3和SGC- 790 1细胞βRARE的转录活性 ,但对 MKN- 45细胞影响不大 ,不能抑制细胞 AP- 1活性 .当RARβ基因转染 MKN- 45细胞后 ,ATRA则能够诱导细胞 βRARE的转录活性 ,并抑制细胞的 AP-1活性 ... 【英文摘要】 The effect of all\| trans retinoic acid(ATRA)is mainly mediated by its receptors,RARs and RXRs.The role of RARβ in growth inhibition by ATRA and the underlying mechanism in human gastric cancer cells were investigated.Expression level of RARβ mRNA was detected by Northern blot.The expression vector containing a RARβ gene was transfected into MKN\|45 cells which did not express RARβ mRNA by CellFECTINtm.Growth inhibition and statue of cells were detected by MTT assay and the method of colony formation of ...国家自然科学基金(39880015)；国家杰出青年科学基金(B 类，39825502)资

Autonomous Mobile Robotic Architecture and Development Research

【中文文摘】阐述了自主移动机器人体系结构的意义,并对分层式体系结构和包容式体系结构这两种典型体系结构详细比较分析后,在此基础上研究了基于两者优点的混合型体系结构。最后,对该领域的研究热点进行了阐述,并对未来的研究工作提出了建议。 【英文文摘】The signification of autonomous mobile robotic archi- tecture is studied in this paper. Hierarchical architecture and subsumption architecture are the two kinds of robotic architec- tures being compared in detail. Based on this analysis, the peper gets the results that the hybrid architecture has advantages of both two types of architectures. Finally, the paper puts forward the hot topics in this area and make some suggestions about the future research

氧化石墨烯改性高温环氧树脂基碳纤维复合材料的热性能与力学性能

采用湿法预浸技术和模压工艺,制备了氧化石墨烯(GO)改性碳纤维/环氧树脂(CF/E54-DDS)混杂复合材料,利用差示扫描量热分析(DSC)、动态热机械分析(DMTA)、无损C扫描等开展了GO对复合材料的热固化性能、凝胶工艺性、动态热机械性能以及抗冲击损伤性能等的影响研究。结果表明,GO结构中的羟基、羧基会促进改性树脂体系的固化反应,GO/E54-DDS的固化反应比E54-DDS的提前,反应变得和缓,且会加速固化反应的进行;在GO含量小于0.5%时,GO的活性基团可增加改性体系的交联密度而提高复合材料的玻璃化转变温度,但GO含量大于0.8%时,会因DDS在固化网络结构中的占比下降较大,反而降低复合材料的玻璃化转变温度;GO/CF/E54-DDS预浸料比CF/E54-DDS表现出更好的浸润效果;CF/E54-DDS复合材料破坏后碳纤维表面光洁,破坏主要发生在碳纤维与树脂基体的界面,而GO/CF/E54-DDS复合材料破坏后,碳纤维表面紧密粘附着GO/E54-DDS固化物,破坏主要发生在碳纤维织物层间的GO/E54-DDS区域;GO的存在提高了GO/CF/E54-DDS复合材料抵抗横向裂纹和纵向裂纹扩展的能力,复合材料的损伤投影面积和凹坑深度减小,提高了冲击后压缩强度。航空科学基金(2016ZF68011);;福建省科技创新平台建设计划(2014H2006);;福建省自然科学基金(2015J01222);;厦门大学石墨烯工业技术研究院资助项目(2014I2005

Study on the Model both Cutting Variable-speed of the Log-core Veneer Lathe and Moving Locus Model with Constant-speed Peeling

详细分析了无卡轴旋切机的工作原理,推导了旋切过程中刀刃进给速度与圆木直径的数学模型,同时得出旋切时间的近似计算式。从中可知,旋切过程中刀刃进给速度必须按一定规律变化才能保证旋切机正常工作。建立了旋切机恒线速旋切的运动轨迹模型,推导出旋切机恒线速旋切时间的精确计算式,并在此基础上提出了旋切时间简便的近似计算式。这些研究结果均可用于指导设计和进行实际生产。Working principle of log-core veneer lathe had been analyzed in detail,and the mathematical model between the knife-carriage feeding speed and the diameter of the log core was established,in the meantime,the approximation cutting time formula was also derived.The feeding speed must be changed with continuousness and a rule,which can let the lathe work well.Moving locus model of invariable-speed peeling was also founded,precision calculating formula of invariable-speed peeling was deduced.In the same time,the simplification cutting-speed formula was also derived.These results of the research will provide a guide for the designing and the producing practice