Measurement uncertainty evaluation of conicity error inspected on CMM

The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification(GPS), the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm(IIEA) is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement(GUM) method to evaluate measurement uncertainty. Adaptive Monte Carlo method(AMCM) is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine(CMM). The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error(MZCE) rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly.     

Genome-Wide Identification,Expansion, and Evolution Analysis of Homeobox Gene Family Reveals TALE Genes Important for Secondary Cell Wall Biosynthesis in Moso Bamboo (Phyllostachys edulis)

The TALE gene family is a subfamily of the homeobox gene family and has been implicated in regulating plant secondary growth. However, reports about the evolutionary history and function of the TALE gene family in bamboo are limited. Here, the homeobox gene families of moso bamboo Olyra latifolia and Bonia amplexicaulis were identified and compared. Many duplication events and obvious expansions were found in the TALE family of woody bamboo. PhTALEs were found to have high syntenies with TALE genes in rice. Through gene co-expression analysis and quantitative real-time PCR analysis, the candidate PhTALEs were thought to be involved in regulating secondary cell wall development of moso bamboo during the fast-growing stage. Among these candidate PhTALEs, orthologs of OsKNAT7, OSH15, and SH5 in moso bamboo may regulate xylan synthesis by regulating the expression of IRX-like genes. These results suggested that PhTALEs may participate in the secondary cell wall deposition in internodes during the fast-growing stage of moso bamboo. The expansion of the TALE gene family may be implicated in the increased lignification of woody bamboo when divergent from herbaceous bamboos.     

铸造多晶硅中铜沉淀的电子束诱生电流

利用电子束诱生电流(EBIC)研究了不同热处理条件下太阳电池用铸造多晶硅材料中的铜的沉淀特性，并与铜在普通直拉硅单晶中的沉淀行为进行了比较。EBIC观察发现，在铸造多晶硅中，热处理的冷却速率和结晶学缺陷(如晶界和位错)共同影响着铜在多晶硅中的扩散和沉淀性质。样品在快速冷却时，在晶界以及晶粒内形成了很高密度且分布较均匀的细小铜沉淀；而在慢速冷却时，则是形成密度较低，较大尺寸的铜沉淀。EBIC的衬度计算显示，慢速冷却下形成的铜沉淀具有更强的复合特性，且铜沉淀在晶界上的分布具有选择性。最后，讨论了铜沉淀在铸造多晶硅中的形成机理。     

经眼动脉灌注治疗兔成视网膜细胞瘤

【摘要】 目的 评估兔成视网膜细胞瘤（retinoblastoma,RB）模型的建立及经导管眼动脉灌注（selective ophthalmic arterial injection,SOAI）治疗兔RB的可行性。方法 HXO Rb44RB细胞予中心细胞室培养,取对数生长期HXO Rb44细胞,用PBS配成浓度为2.0 × 107个/ml的细胞悬液,抽取0.1 ml细胞悬液注射于6只SPF级新西兰兔右眼视网膜间隙下。接种肿瘤细胞前3 d和注射后1个月臀部注射环孢素A 15 mg?kg-1?d-1,1个月后减量至10 mg?kg-1?d-1并持续到实验结束。将RB兔分为对照组3只和实验组3只,对照组灌注0.9%氯化钠溶液15 ml,实验组将美法仑2.5 mg用0.9%氯化钠溶液稀释至15 ml后灌注。术后分别于7、14 d比较两组肿瘤生长情况。结果 注射环孢素A期间,实验兔不良反应轻微,6只均建模成功。7次插管中6次成功插至眼动脉。SOAI术后1周,实验组肿瘤可见明显缩小,2周后均消失。SOAI术后,实验组仅1只见右眼轻度红肿、流泪,1周后红肿自行消退。结论 SOAI治疗RB兔具有可行性,为进一步经眼动脉灌注治疗RB的基础研究提供了参考。

     

基于全站仪三维坐标测量的钢结构制作精度控制方法研究

基于全站仪的三维坐标测量与数据分析系统的精度控制方法,在钢结构加工制作领域中具有较大的应用前景。为此,对基于全站仪三维测量的精度控制技术进行介绍,着重探讨三维坐标严密转换算法及算法的Matlab软件程序,实现测量数据与实际数据的直接对比,为全站仪三维测量在钢结构制作精度控制上的研究提供相应参考依据。     

Synthesis and photocatalytic performance of Ag-loaded β-Bi2O3 microspheres under visible light irradiation

The visible-light-driven photocatalyst Ag/β-Bi₂O₃ microspheres were synthesized by a simple chemical method. First, β-Bi₂O₃ microspheres were obtained by a thermal treatment of sphere-like Bi₂O₂CO₃ precursor at 360 °C for 3 h in air and then Ag nanoparticles were in situ incorporated into β-Bi₂O₃ microspheres by impregnation method. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and photoluminescence measurements. The experimental results demonstrated that the visible light absorption of β-Bi₂O₃ photocatalyst is greatly enhanced with the incorporation of Ag nanoparticles. The SEM and TEM observations revealed that the Ag nanoparticles can be homogenously incorporated in the β-Bi₂O₃ microspheres. The photocatalytic activity of Ag/β-Bi₂O₃ sample was evaluated by the photodegradation of the Rhodamine-B under visible light irradiation as a function of Ag content. It is found that the photocatalytic efficiency of β-Bi₂O₃ can be significantly improved with the incorporation of Ag nanoparticles up to 2.0 wt% Ag. The mechanism for the enhanced photocatalytic activity is also presented.     

A Parametric Study of Beam Steering for Ultrasonic Linear Phased Array Transducer

All the parameters of a linear phased array may affect the performance and cost of the ultrasonic inspection system. The characteristic of the acoustic field for an array transducer is the most important factor whether the echo information of the inspected area in a specimen can be obtained and utilized effectively, and it is the main basis of designing a phased array. A mathematical model was presented to simulate the characteristic of an acoustic field radiated from an ultrasonic linear phased array on the basis of Huygens' principle. Based on the model, the beam directivity function can be obtained, and the effects of inter-element spacing, number of elements, element width, and transducer center frequency on beam directivity and steerability in a linear phased array transducer are systematically discussed.     

Hydrocracking of Gudao Residual Oil with Dispersed Catalysts Using Supercritical Water-Syngas as a Hydrogen Source

Heavy oil upgrading is a very important process in the petroleum industry, but is very difficult because it has a high impurity content. A variety of heavy oil upgrading technologies have been developed in the world, including the catalytic hydrocracking process, which can process various heavy oils with a high yield of liquid products. Although this technology is one of the most widely used methods for upgrading heavy oil, the use of expensive molecular hydrogen is costly. The heavy oil upgrading technology with alternative hydrogen is very important. The catalytic hydroconversion of Gudao residue with different catalysts using water-syngas as an alternative hydrogen was investigated in this study. Hydrogen is provided in-situ for hydrocracking through the water-gas shift reaction (WGSR). The experimental results show that catalysts play a very important role in catalytic hydroconversion of Gudao residue using water-syngas as an alternative hydrogen. Addition of catalysts to residue was found to improve the distribution or properties of cracking products and inhibit the asphaltene or TI formation.     

渣油胶质和沥青质在分散型催化剂作用下的临氢热反应行为

采用四组分法从辽河减压渣油中分离出胶质、沥青质，分别考察了它们在分散型催化剂作用下的临氢热反应行为。结果表明，胶质、沥青质一方面要裂化生成较轻的产物；另一方面也要发生缩合反应生成较重的反应产物以及甲苯不溶物。渣油在临氢热反应过程中，沥青质是生焦的主要来源，其次才是胶质。比较了热反应生成的沥青质与原生沥青质之间以及热反应生成的胶质与原生胶质之间化学组成的区别，结果表明，反应生成的沥青质和胶质较原生的沥青质和胶质分子结构缩合程度高，并且反应苛刻度越高，缩合程度也越高。     

单色光光电导衰减法测试硅单晶少子寿命的表面复合修正公式

本文在数值分析和实验数据的基础上，提出了用单色光高频光电导衰减法测量硅单晶少子寿命的表面复合修正公式。