Micro-robot design based on swimming mechanism of bacterial flagella

Nanomachines are controllable machines at the nano meter or molecular scale that are composed of nano-scale components. They have their own mechanochemistry, dynamics, workspace, and usability and are composed of natures building blocks: namely proteins, DNA, and other compounds. Some bacteria (i. e. Escherichia coli) swim by rotating helical flagella. The structure and motion character of the flagellum are introduced. Through the study, a micro-robot was designed and its mechanical structure was explained in this paper. In the future, the bionic micro-robot is expected tobe built, which can travel inside the human body and carry out a host of complex operations such as minimally invasive surgery, highly localized drug delivery, and screening for diseases that are in their very early stages. It is important to medicine and could be applied in other areas, including space exploration, electronics and military.     

Micro-robot design based on swimming mechanism of bacterial flagella

Nanomachines are controllable machines at the nano meter or molecular scale that are composed of nano-scale components.They have their own mechanochemistry,dynamics,workspace,and usability and are composed of nature's building blocks:namely proteins,DNA,and other compounds.Some bacteria(i.e.Escherichia coli)swim by rotating helical flagella.The structure and motion character of the flagellum are introduced.Through the study,a micro-robot was designed and its mechanical structure was explained in this paper....     

无损伤医用肠道机器人驱动机理

提出了一种结构简单的医用肠道机器人的驱动机构．利用弹性流体动压润滑理论，详细分析计算了肠道机器人在不同弹性模量、不同半径和不同粘液粘度的肠道内的轴向运行速度和形成的粘液膜厚度．肠道实验研究结果表明，该肠道机器人能以较快速度在肠道内悬浮运行．     

基于快速转弯微小机器人系统的研究

介绍了一种基于尺蠖运动原理的能实现快速转弯的微小机器人系统,并对机器人进行了设计和制作,组装了实验用机器人样机,通过AT89C52单片机及其外围驱动控制电路对机器人行走和位置信号的产生进行控制,并通过二维PSD对微机器人的三维位置进行检测,取得了与理论一致的结果.实现了对该机器人的行走运动和位置检测控制的功能,为对该类机器人的进一步研究提供了一个新的思路.     

微小步行爬壁机器人的电磁直接驱动方式

研究了利用两组电磁力交互作用,直接驱动微小步行爬壁机器人的方法,分析了单层驱动方式、双层驱动方式和差动式驱动方式的原理,并进行了三种驱动方式的对比实验,为微小步行爬壁机器人驱动装置的设计与研制奠定了基础。     

Study of an inchworm-like micro-robot

A micro-robot with 4 DOFs is presented in this paper. An inchworm-like biped mechanical structure is selected with the advantages of small size and minimal weight. It can walk on wall as an inchworm with two different locomotion modes such as crawling and overturn. With rotation mode, this robot can change it＇ s motion direction. The robot can also transit between different surfaces. The kinematics model of the robot has been analyzed. A DSP based embedded controller is used for minimal power consumption and efficient control. The micro-robot can move flexibly and fit complicated un-structural environment well.     

脉动流场中血管微型机器人的运行研究

研究一种应用于人体血管的新型螺旋式微型机器人.利用机器人机体内外表面不同旋向的螺旋槽和在液体环境中不同转向的高速旋转,实现机器人的悬浮式快速运行.在模拟人体主动脉的脉动流场环境下,运用计算流体力学(CFD)方法数值研究螺旋机器人在一定的运行速度下,机器人内外螺旋的轴向驱动力、轴向力矩以及机器人对血管壁的压力,并且分析机体的内外转速和机器人运行速度对机器人轴向驱动力和血管壁所受压力的影响.研究结果表明:血管壁所受最大压力和机器人内外螺旋轴向驱动力变化基本和血流速度变化趋势一致,机体外螺旋所受轴向力矩为负值,机体内螺旋所受轴向力矩为正值;随着机体内外转速的增加,血管壁所受最大压力和机器人的轴向驱动力都随之增大,机体外螺旋转速的增加更有利于机器人轴向驱动力的增大;随着机器人运行速度的增大,机器人轴向驱动力先增大,当运行速度达到一定值时,机器人轴向驱动力又随之减小.实验证明这种螺旋机器人可以在顺流和逆流的流体环境中运行.     

波纹-负泊松比蜂窝混合芯夹层板的自由振动

夹层板作为一种复合材料结构,其芯层在系统特性中起着重要作用。基于三阶剪切变形理论(third-order shear deformation theory, TSDT),通过Rayleigh-Ritz法研究了由梯形波纹与具有负泊松比的蜂窝组成的混合芯夹层板的自由振动,分析了边界条件及参数变化对夹层板振动特性的影响。结果表明,边界条件、芯层结构与蜂窝倾角对夹层板的固有频率有重要影响。研究结果对混合芯夹层板结构在工程应用中的设计与优化具有一定的理论指导意义。     

地下构筑物挡水效应对地表沉降参数敏感性影响分析

以比奥固结理论为基础,建立设置挡水构筑物与否的多种工况下的地面沉降有限元模型。计算分析开采不同含水层时地表沉降的特征,在此基础上设置逐渐深入地下的挡水构筑物,分析其挡水效应对抽水引起的地面沉降的影响。以最大地面沉降为指标,结合MATLAB编程计算,比较土体随机变量分布参数相对敏感性大小,并分析挡水构筑物对土体参数敏感性和结构可靠度的影响,最终加以公式推导验证参数敏感性的变化。结果表明:在边界不透水的情况下,开采含水层越深,地面沉降量越大,且挡水构筑物入深增大,最大沉降量和沉降差均增大;但是随着挡水构筑物深入地下,挡水构筑物两侧的地面沉降规律有所不同,开采井一侧为逐渐增大,另一侧足够远处为先增大后减小,沉降量变化幅值较小。影响地面沉降的土体参数按敏感性从大到小排序依次是弹性模量、渗透系数、泊松比、密度、内摩擦角,其中内聚力和孔隙比敏感性极小;分析挡水构筑物的设置对各参数敏感性的影响可知,土体渗透系数和与侧摩阻力正相关的参数(即泊松比、内摩擦角、内聚力)敏感性增大,其余参数敏感性减小,因此在分析地面沉降时,应适时考虑侧摩阻力的影响。地下挡水构筑物的设置和考虑弹性模量与渗透系数的正相关性计算得到的结构可靠度均减小。土层由侧摩阻力控制的沉降量大小取决于土层的沉降差和变形土层厚度。     

征沙村地区三工河组低渗透砂岩储层孔隙结构研究

低渗透砂岩储层孔隙结构复杂,制约了该类型油藏的高效勘探开发,一直是地质学者研究的关键问题。以准噶尔盆地征沙村地区侏罗系三工河组低渗透砂岩储层为研究对象,利用岩石薄片、铸体薄片、扫描电镜、X射线衍射等微观测试方法,结合常规压汞、恒速压汞及核磁共振等岩石物理分析手段,系统地对孔隙结构进行了综合研究。结果表明:该区低渗透砂岩储层的岩石类型以长石岩屑砂岩为主,储集空间主要为残余粒间孔和粒间溶孔;喉道半径的差别是造成渗透率级差的主要控制因素;核磁共振横向弛豫时间T_2的分布与孔隙半径有较好的对应性,可以有效评价可动流体孔隙特征。研究对本地区的勘探开发具有积极作用,可以应用到其他相似低渗透砂岩油气藏评价中。     

Ultrastructure of spermatozoa of Bullacta exarata （philippi） and its significance on reproductive evolution and physio-ecological adaptation

The morphology and ultrastructure of Bullacta exarata spermatozoa observed by light and transmission electron microscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal complex and an elongated nucleus, and tail with a midpiece, principal piece and an end piece. The midpiece consists of a mitochondrial ring, and the principal piece is composed of axoneme and lateral fin. The structure of B. exarata spermatozoa differs significantly from that of other gastropods, especially in the lateral fin and the principal piece, which was described scarcely before. A comparison is made between B. exarata and other gastropods, and its significance on reproductive evolution and physio-ecological adaptation is preliminarily discussed.     

新型六杆四面体扭网壳的构形、静力和稳定性能

提出了一种基于投影平面为四边形的六杆四面体单元组成的新型扭网壳(简称六杆四面体扭网壳),研讨了六杆四面体扭网壳结构的构形,它构造简单,节点和杆件数相对较少,网格抽空率高,兼有单层和双层网壳的优点.针对上、下弦节点为半刚接半铰接六杆四面体单块扭网壳作了静力和线性与非线性稳定性分析,结果表明上弦杆全部受压,下弦杆全部受拉,腹杆除周边一、二圈局部杆件受压外大部分也都受拉,各类杆件内力变化幅度很小,有利于杆件截面选配,提高材料的利用效率.结构的整体刚度好,结构的双非线性稳定系数对比于相应特征值屈曲系数降幅很小,用钢指标优越.这类网壳结构在两种网格抽空方式的单块扭网壳、三种形式的四块组合型扭网壳和一种两块组合型扭网壳中有推广应用的前景.     

皱马鞍菌子囊盘（菌盖）结构的光学显微镜和扫描电镜观察

通过光学显微镜和扫描电镜的观察，了解到皱马鞍菌的子囊盘（菌盖）是由子实层、囊层基、囊盘被３个部分组成。其子实层是由子囊和侧丝镶嵌排列组成。前者呈圆筒形、具柄，内含８个椭圆形的、外壁具网纹的、单行排列的子囊孢子。顶端不增厚，无顶端装置，但具纵裂缝，成熟的子囊孢子由裂缝散发出来；后者细长，具横隔，由多细胞组成。在子实层排列中，其顶端膨大部分超过了子囊的高度，聚集形成假囊层被。其囊层基位于子实层与囊盘被     

微波加热高碳锰铁粉固相脱碳显微结构

对脱碳物料进行碳含量测定并采用电子探针及X线衍射(XRD)进行显微结构和物相分析。研究结果表明:在实验件下,高碳锰铁粉的碳含量由6.61%分别降至1.54%,1.13%,1.05%,0.94%;脱碳物料的显微结构主要为包裹与镶嵌结构、球形层状结构和实心球形结构,物相组成主要为金属锰、金属锰铁、低碳锰铁碳化物和氧化钙。脱碳温度在900℃时的综合脱碳效果最好,脱碳物料的氧化程度低且无锰酸钙等成分。     

基于摩擦力控制结肠内窥镜机器人

为了提高肠道疾病主动诊断能力,研究了基于摩擦力控制的结肠微型机器人.摩擦力模型分析了肠道摩擦力控制因素,并利用实验模板和黏附制剂在体外肠道开展的摩擦力实验,验证了接触纹路和接触黏度对肠道摩擦力的影响.摩擦接触装置的研制综合考虑了肠道应用环境和摩擦力控制因素,最终装配在内窥镜机器人样机上实现了摩擦控制运动.实验结果表明：基于摩擦力控制内窥镜机器人样机能够适应不同的运动环境而实现有效的主动运动,且运动环境会对其运动速度产生不同影响.     

塔里木盆地煤显微组分显微傅里叶红外光谱特征及意义

应用显微红外光谱技术,对塔里木盆地侏罗纪煤中有代表性的3种组分角质体,镜质体、丝质体在不同热模拟温度下的结构组成变化特征进行了研究,结果表明：角质体结构组成中含有较丰富的长链脂族结构,而芳香结构和含氧官能团的含量则相对减少;与此相反,丝质体结构组成中芳香烃占绝对优势,而脂族结构含量则很少,镜质体结构组成介入体和丝质体之间,含有较多的短链脂族结构和芳香结构。据此推断,角质体具有高的生烃潜力,是一种倾油组分;镜质体生烃潜力中等,是一种倾气组分,但也可以生成一定数量的液态烃;丝质体生烃潜力很小,对煤成烃的贡献微不足道,另外,随热模拟温度的升高,3种组分中的脂族结构和含氧官能团都呈现明显的由强到弱的变化,而芳香结构比较稳定,在整个生烃热演化过程中则呈现芳环缩合度增加芳烃相对富集的趋势。由此说明,煤生烃过程主要是一种脂族结构和含氧基团不断脱落,芳香结构不断缩聚的过程。     

龙门山岩石圈地壳三维结构及汶川大地震成因浅析

地质构造研究和地震测深剖面的构造解析显示,龙门山碰撞遣山带岩石圈存在既有显著差异又有密切联系的两套断裂系统:一是以地壳表层脆性剪切带为主的浅层断裂系统;另一是以切割莫霍界面或壳幔过渡带的壳幔韧性剪切带为主的深部断裂系统.根据地质构造和地震测深成果的综合研究,在建立起龙门山遣山带及邻区岩石圈地壳结构模型的基础上,论述了两套断裂系统的特征与相互关系,提出岩石圈壳幔韧性剪切带可能是四川汶川8.0级强烈地震的发震构造之一,以及强烈地震形成的动力学模式等.     

Three-dimensional recon- struction and analysis of structure characteristics on senile plaques of Alzheimer’s disease

Alzheimer‘s disease is a progressive neurodegenerative disorder characterized by the presence of senile plaques primarily composed of amyloid β in brain. Abnor-mal secretion and aggregation of amyloid β are the key events in pathogenesis of Alzheimer‘s disease. Reduction of amyloid β production and inhibition of amyloid β aggregation to form senile plaques are hopeful strategies for the treatment and prevention of Alzheimer‘s disease. In the present study, the silver and immunohistochemical staining methods were applied to discover senile plaques in the hippocampus of Alzheimer‘s disease patients, and then images were processed and three-dimensionally reconstructed by Matlab and AVS software. The structure characteristics of senile plaques were measured through correlation function calculation and fractal dimension by a computer-aided method. Diffuse plaque had no amyloid center, but classic plaque presented compact central core structure; two types of plaques were both of porous structure, but the sizes of their pores were significantly different. Furthermore, there was difference in fractal dimension value between the diffuse plaque and classic plaque in the two staining methods. The comparison of structure characteristics between two types of plaques indicated that they developed independently. Establishment of the methods for reconstructing the three-dimensional structure of senile plaque and analyzing their structure characteristics is helpful for further study on the aggregation mechanism of senile plaque.     

论社会结构理论下和谐社会关系的构建——以警察对公众态度的差别为视角

社会结构是由个人的社会行动及其相互作用的模式构成。探讨警察等公职人员在执法过程中面对不同的社会阶层所采取的手段以及实施执法活动的内容、结果的区别．可以为如今日趋紧张的警民关系找到一个解释的出口，也可为警察及其他行为人的行为提供指引。     

一种新型智能控制系统模型的研究

分析智能系统中智能行为之源，提出一种新型递阶式智能控制系统结构原型，并给出了相应的综合集成具体实施策略，这种新型递阶式智能控制系统结构原型由决策级，反应级和适应级组成，它们既各司其中，又相互配合，有机协调，较全面地模拟了人的智能行为，并因此提高了系统的智能水平，这种新型递阶智能控制系统结构原型可为智能控制系统进一步的设计和实施提供基础。