关于三坐标测量机基础扫描功能在工件内嵌复杂曲面测量的应用

提出了一种使用三坐标测量机测量工件内嵌复杂曲面的详细测量方法,即利用三坐标测量机的基础扫描功能,通过编辑测量程序时采用的定位角向、手动扫描曲面型线,最后导出型线数据,通过数模比对得出内嵌复杂曲面的偏差数据,实际测量表明,该方法具有一般性,且易于企业在装备基础功能的三坐标测量机时完成内嵌复杂曲面产品的自检工作,对降低企业质检成本、提高企业质检效率有很好的指导作用。

Flotation bubble seed image filling algorithm based on boundary point features

Bubble seed image filling is an important prerequisite for the image segmentation of flotation bubble that can be used to improve flotation automatic control. These common image filling algorithms in dealing with complex bubble image exists under-filling and over-filling problems. A new filling algorithm based on boundary point feature and scan lines ~PFSL） is proposed in the paper. The filling a｜gorithm describes these boundary points of image objects by means of chain codes. The features of each boundary point, including convex points, concave points, left points and right points, are defined by the point＇s entrancing chain code and leaving chain code. The algorithm firstly finds out all double-matched boundary points based on the features of boundary points, and fill image objects by these double-matched boundary points on scan lines. Experimental results of bubble seed image filling show that under-filling and over-filling problem can be eliminated by the proposed algorithm.

In vitro antitumor activity and targeted sites of two novel platinum-based(II) complexes on SW620 colon cancer cell line

Objective:The aim of our study was to evaluate the in vitro antitumor activity of two novel platinum-based(II) complexes(2.3-pyridinedicarboxylic acid dehydrate platinum and 2.3-pyrazinedicarboxylic acid dehydrate platinum),which were concurrently provided with hydrophilic carboxyl group and lipophilic pyrazinyl or pyridyl group,on SW620 colorectal cancer cell line and the impact of the two compounds on the cell cycle and apoptosis of the cells when compared with the oxaliplatin,desiring the new ligand combined with hydrophilic and lipophilic properties would facilitate the transportation and transmembrane of the drugs,showing a better antitumor activity.Methods:After SW620 cells were treated with different doses of the three platinum-based agents for 24,48 and 72 h,the cell proliferation inhibition rate was determined using methyl thiazolyl tetrazolium(MTT) assay;the morphology of cells were evaluated under inverted microscope;the changes in cell cycle were determined using flow cytometry;the percent apoptosis was measured using Annexin V/PI double staining and the micromorphology of the cells after drug exposure was evaluated using scanning electron microscopy.Results:The evaluation on the proliferation inhibition rate revealed that the three platinum-based agents inhibited the SW620 cells in a time-and dose-dependent manner and showed different strengths as pyridine > pyrazine > Oxa.Under optical microscope,the morphological changes such as cell shrinkage,round cells and dead cells were frequently observed after drug exposure.Cell cycle determination showed that all of the three agents could function to block the cells converting from phase S to phase G2M.Apoptosis evaluation revealed that the three agents promoted the apoptosis of SW620 cells in a time-and dose-dependent manner and showed different strengths as pyridine > pyrazine > Oxa.Typical early and late apoptotic morphological changes could be detected during electron microscopy.Conclusion:The two novel platinum-based(II) complexes showed a stronger antitumor effect on SW620 cells than oxaliplatin,with the targeted site at a certain phase of cell cycle and apoptosis.

Fabrication of single-walled carbon nanotube-based highly sensitive gas sensors

A highly sensitive single-walled carbon nanotube(SWCNT)-based ammonia(NH3) gas detector is manufactured by orderly assembling SWCNT using the dielectrophoretical(DEP) technology.Atom force microscopy(AFM) and scanning electron microscopy(SEM) images revealed that SWCNTs were assembled between the microelectrodes.SWCNTs were affected by the electrophoretic force which was carried out by the related theoretical analysis in a nonuniform electric field.The SWCNT field effect transistors geometry was obtained.The electrical performance of NH3 gas sensor with the SWCNT field effect transistors geometry was tested before and after the adoption of NH3 at room temperature.Experimental results indicated that the efficient assembly of SWCNT was obtained by the applied alternating current voltage with frequency of 2 MHz and amplitude of 10 V.The SWCNTs-based gas sensor had high sensitivity to NH3,and the electrical conductance of NH3 gas sensor reduced two times after interaction with NH3.The SWCNTs surface gas molecules were removed by means of ultraviolet ray irradiation for 10 min.Hence,the fabricated NH3 gas sensor could be reversible.There is a clear evidence that the adsorption of NH3 on the SWCNT channel is easy to be realized.Our theoretical results are consistent with recent experiments.