A Study on Flexible Measuring System Based on CMM

随着市场竞争的日益激烈，对产品提出了T、Q、C、S的要求，即时间更短、质量更好、成本更低、服务更优。综合产品设计、制造、检测等各个环节的质量自动控制系统成为发展的必然。其中，快速、精确的三维测量是制造过程中的重要环节，贯穿整个设计、开发、加工、检测与质量保证的过程。三坐标测量机（CMM）是制造业中的标准三维精密测量设备，广泛使用于航空航天、汽车、造船、装备制造及模具制造等领域。但目前在对工件表面进行测量与评价时，主要是靠人工编程操作获取被测工件表面的三维特征，这不仅需要大量的人工工作量，而且使得测量结果依赖于检测人员的经验和对工件检测原则的理解，其测量效率低，不能适应制造业快速发展的要求。本课...With the increasingly fierce competition of market, products are demanded with T, Q, C, S, which means shorter time, better quality, less cost and better service. Rapid acquisition of high-precision coordinate data from parts having complex geometry is one of the most important techniques in modern manufacturing process. Among many coordinate acquisition methods, Coordinate measuring machine are w...学位：工程硕士院系专业：物理与机电工程学院机电工程系_仪器仪表工程学号：X200518201

三坐标测量机零件位置自动识别系统的实现

被测量零件在三坐标测量机位置的自动识别是实现三坐标测量机智能化的关键技术。将CMOS相机与激光器通过夹具固定在三坐标测量机测座上,实现与接触式测头的多传感器集成系统;采用机器视觉方法获取被测量零件的视觉坐标;用VISuAl bASIC 6.0应用程序开发工具对CAd模型接口问题做出了解决方案,实现了从CAd模型中自动提取检测特征与公差要求;根据零件三维信息的获取与图像处理,实现了零件在图像坐标系中位置和方向的自动识别;利用各坐标系之间的转换关系,实现了零件在三坐标测量机机器坐标系中位置和方向的自动识别功能

3D vision measurement based on shape from silhouette

提出了一种将SHAPE frOM SIlHOuETTE(SfS)技术应用在三坐标机上的新方法,即用摄像机获取图像,用三坐标机作移动平台,构建视觉测量系统,应用SfS技术对物体进行三维测量。该视觉测量系统扩展了坐标机功能,扩大了其应用范围。实验结果表明,该视觉测量系统具有SfS技术和坐标机两者的优点,重构物体三维模型的过程简单快捷,精度高于0.4MM,其结果可作为坐标机智能测量的基础,是一种非常实用的方法。Shape from Silhouette(SfS) is a passive non-contact 3D measurement method,which is used in 3D modeling and reverse engineering etc.Using SfS method,a simple,low cost,efficient and accurate 3D information acquisition system can be established and the request of the surface material of the object that is measured is low.Compared to laser scanning,SfS can also measure an object with hole.A new method that Shape from Silhouette is applied to measure the objects in coordinate metrology is proposed,that is the vision measurement system is made up of the camera,the coordinate metrology and SfS.Intelligent measurement is carried out on the vision measurement system to 3D reconstruction and consequently the precision is improved.The functions of coordinate metrology are expanded and the applications of coordinate metrology are enlarged by the system.The running experiment results on the vision measurement system show that this system has SfS and coordinate metrology's advantages.The approach to 3D reconstruction is very efficient and the accuracy is higher than 0.4mm.This approach is a much applied way and it can be a foundation of intelligent measurement

Cloning and sequence analysis of psbA gene fragment from the chloroplast of Platymonas subcordiformis

psbA基因是叶绿体基因组中一个重要的光调控基因,编码光和系统Ⅱ反应中心的D1蛋白.根据叶绿体基因组序列高度保守的特性,利用莱茵衣藻(Chlamydomonas reinhardtii)psbA基因的保守序列(基因登录号:HQ667991.1)设计引物,采用PCR步移的方法从亚心型扁藻(Platymonas subcordiformis)基因组DNA中克隆到psbA基因全长(基因登录号:KF528742).序列分析表明,亚心型扁藻psbA基因全长1939 bp,编码区长度为1062 bp,推导编码353个氨基酸,包括4个赖氨酸残基.有效密码子数显示psbA基因具有明显的密码子偏好性,并且偏好使用以A/T结尾的密码子.相对同义密码子使用度表明25个密码子在编码使用时具有偏好性,其中20个密码子以A/T碱基结尾,占到80%.其终止密码子使用了TAG

The screening, identification of alginate degrading bacteria and optimization of fermentation conditions

以褐藻酸钠为唯一碳源,从腐烂海带中筛选得到褐藻酸钠降解能力较强的菌株 H4,经生理生化和16S rDNA序列分析鉴定该菌株属于交替单胞菌属(Alteromonas)。对菌株H4的发酵条件优化研究表明, H4的较优培养基组成为(w/v)：褐藻酸钠0.6%、酵母粉0.5%、蛋白胨0.25%、NaCl 3%；较优培养条件为：培养温度28℃,初始pH7.5,接种量1.5%(v/v),培养时间48 h。Fe~(3+)对交替单胞菌H4的产酶有明显的促进作用,这在其他褐藻酸裂解酶生产菌株中未见报道,而 Cu~(2+)对褐藻酸裂解酶的抑制作用高达45.78%。在优化后的培养条件下,粗酶液酶活达到146.45 U/mL,较优化前提高了39.4%

一株高效褐藻酸降解菌的筛选、鉴定及其发酵条件的优化

以褐藻酸钠为唯一碳源,从腐烂海带中筛选得到褐藻酸钠降解能力较强的菌株 H4,经生理生化和16S rDNA序列分析鉴定该菌株属于交替单胞菌属(Alteromonas)。对菌株H4的发酵条件优化研究表明, H4的较优培养基组成为(w/v)：褐藻酸钠0.6%、酵母粉0.5%、蛋白胨0.25%、NaCl 3%；较优培养条件为：培养温度28℃,初始pH7.5,接种量1.5%(v/v),培养时间48 h。Fe~(3+)对交替单胞菌H4的产酶有明显的促进作用,这在其他褐藻酸裂解酶生产菌株中未见报道,而 Cu~(2+)对褐藻酸裂解酶的抑制作用高达45.78%。在优化后的培养条件下,粗酶液酶活达到146.45 U/mL,较优化前提高了39.4%

Genome-wide analysis of putative sugar transporter proteins in eukaryotic microalgae

Sugar transporter proteins are located in the cell membrane and are a group of important transmembrane proteins.Sugar transporter proteins transport carbohydrate from extracellular to intracellular for the use of cells.Sugar transporter proteins,as sugar sensors,play an important role in eukaryotic microalgae,breast-feeding animals and higher plants.In this study,comparative genomics analyses were applied to study sugar transporter proteins and to explore their distribution,classification,phylogeny,evolution and structure in eukaryotic microalgae.Twenty-eight eukaryotic microalgae genomes were examined for putative genes of sugar transporter proteins and 70 putative sugar transporter protein sequences were found,which were 9 types of HUP1,39 types of HUP2 and 22 types of HUP3.Sugar transporter genes of eukaryotic microalgae were origin of bacterium.In this study,a general framework of the sequence-structure-function connections of the sugar transporter genes was revealed.</p

Study on purification and antioxidative activity of polysaccharides from Enteromorpha

利用DEAE-Cellulose52离子交换层析和Sepharose4B凝胶过滤层析时浒苔粗多糖进行了纯化,并采用Fenton反应和邻苯三酚自氧化法研究了粗多糖和纯化多糖EP-Ⅱ的体外抗氧化活性.结果显示,利用热水浸提、sevag法除掉蛋白质和95%乙醇沉淀后得到的粗多糖,经两步层析后可得到纯化的多糖组分EP-Ⅱ.浒苔粗多糖和EP-Ⅱ都能有效地清除羟基自由基(·OH),且均呈现一定的量效关系,当浓度为0.6mg/mL时,对羟基自由基(·OH)的清除率分别达到44%和59%.两种多糖对超氧阴离子自由基(O_2~-·)清除作用较弱

浒苔多糖的纯化及抗氧化活性研究

利用DEAE-Cellulose52离子交换层析和Sepharose4B凝胶过滤层析时浒苔粗多糖进行了纯化,并采用Fenton反应和邻苯三酚自氧化法研究了粗多糖和纯化多糖EP-Ⅱ的体外抗氧化活性.结果显示,利用热水浸提、sevag法除掉蛋白质和95%乙醇沉淀后得到的粗多糖,经两步层析后可得到纯化的多糖组分EP-Ⅱ.浒苔粗多糖和EP-Ⅱ都能有效地清除羟基自由基(·OH),且均呈现一定的量效关系,当浓度为0.6mg/mL时,对羟基自由基(·OH)的清除率分别达到44%和59%.两种多糖对超氧阴离子自由基(O_2~-·)清除作用较弱

Transcriptome analysis of signal transduction pathway involved in light inducing astaxanthin accumulation in Haematococcus pluvialis

The unicellular green alga Haematococcus pluvialis is the best source of natural astaxanthin(AST)in the world due to its high content under stress conditions.Although high light(HL)can effectively induce AST biosynthesis,the specific mechanisms of light signal perception and transduction are unclear.In the current study,we used transcriptomic data of normal(N),high white light(W),and high blue light(B)to study the mechanisms of light inducing AST accumulation from the point of photoreceptors.The original data of 4.0 G,3.8 G,and 3.6 G for N,W,and B were obtained,respectively,by the Illumina Hi-seq 2000 sequencing technology.Totally,51 954 unigenes(at least 200 bp in length)were generated,of which,20 537 unigenes were annotated into at least one database(NR,NT,KO,SwissProt,Pfam,GO,or KOG).There were 1 255 DEGs in the W vs N,1 494 DEGs in the B vs N,and 1 008 DEGs in the both W vs N and B vs N.KEGG enrichment analysis revealed that photosynthesis,oxidative phosphorylation,carotenoid biosynthesis,fatty acids biosynthesis,DNA replication,nitrogen metabolism,and carbon metabolism were the significantly enriched pathways.Moreover,a large number of genes encoding photoreceptors and predicted interacting proteins were predicted in Haematococcus transcriptome data.These genes showed significant differences at transcriptional expression levels.In addition,15 related DEGs were selected and tested by qRT-PCR and the results were significantly correlated with the transcriptome data.The above results indicate that the signal transduction pathway of "light signal-photoreceptors-interaction proteins-(interaction proteins-transcription factor/transcriptional regulator)-gene expression-AST accumulation" might play important roles in the regulation process,and provide reference for further understanding the transcriptional regulation mechanisms of AST accumulation under HL stress