69 research outputs found
大口径光学元件的精密磨抛与检测装备开发及应用
大口径光学元件超精密加工是一个复杂的系统性工程,涉及精密机床、数控、加工技术与工艺、精密检测和补偿控制等机电控各领域的专业知识,其发展与一个国家的高端制造技术及装备发展能力息息相关,也是一个国家综合国力的集中体现。主要介绍了厦门大学微纳米加工与检测联合实验室在大口径光学元件超精密加工技术及装备方面取得的研究进展,针对大口径光学元件磨削和抛光两个加工流程及其配套的精密检测技术,详细阐述了磨削装备及单元技术、可控气囊抛光机床及相关单元技术、精密检测装备及相关单元技术等的研究应用情况。这些技术研究从超精密加工的需求出发,借鉴国内外的研究经验和成果,通过对装备、工艺、检测等各方面整合,形成了具有自主知识产权的集磨削、抛光和检测装备及工艺技术的大口径光学元件超精密加工体系,这些技术与装备确保了大口径光学元件的高质量超精密加工。国家自然科学基金项目(51675453);;深圳科技计划项目(JCYJ 20160517103720819
Surface texture analysis for ultra-precision flycutting machining based on the dynamic characteristics of machine tools
采用超精密飞切加工技术可获得软脆性平面光学元件的最终表面,而元件表面微观形貌的加工可控性对于光学元件使用性能有直接影响。首先运用多尺度小波分解方法,对飞切机床的加工表面波纹进行了特征提取,得到了工件表面波纹的频率组成及占比;然后通过对机床主轴系统的有限元分析,结合冲击振动测试,找到了与工件表面波纹对应的模态;最后通过对机床的在线振动测试及加工实验进一步明确了飞切加工表面微波纹的成因。结果表明:表面波纹在17 mm左右的空间周期上存在最大的分量,显著影响光学元件的精度和使用效果,该波纹由主轴系统在间断切削的冲击响应所引起,可以通过改变主轴结构实现波纹频率和幅值的控制。Ultra-precision flycutting is widely used to machine soft and brittle plane optical elements,and the controllability of micro surface texture affects the performance of the element directly. The multi-scale wavelet decomposition was used to detect the wave feature of the optical element machined by flycutting machine tool,and the frequency and percent of the waves were achieved. The relevant modals of those waves were found by the finite element analysis and the response test of the spindle system. Particularly,online vibration test and machining experiments were conducted to verify the factor bringing about the micro surface texture on the element. The results show that the micro surface texture at a space period of 17 mm is the most prominent and will make worse observably the accuracy and application of the element,which is caused by the response of the spindle system during the machining process. In addition,modifying the structure of spindle system can make a difference on the amplitude and frequency of the wave.国家级基金(2013ZX04006011-102-001
Technology and Application of Ultra-precision Machining for Large Size Optic
大口径光学元件超精密加工技术是多种学科新技术成果的综合应用,促进了民用和国防等尖端技术领域的发展,在国家大光学工程的推动下,我国的超精密加工技术取得显著的成果。围绕大口径光学元件“高精度磨削+确定性抛光“超精密加工体系,介绍该领域研究进展及厦门大学微纳米加工与检测联合实验室取得的相关研究成果,主要针对光学元件磨削和抛光两个加工流程,详细分析磨削装备技术、磨削工艺技术、精密检测技术、可控气囊抛光技术、加工环境监控技术和中频误差评价技术等关键技术的研究应用情况。这些技术研究从超精密加工的需求出发,借鉴国内外的研究经验和成果,通过对装备、工艺、检测等各方面整合,形成具有自主知识产权的大口径光学元件磨抛超精密加工体系,从而实现大口径光学元件高精度、低缺陷加工。The ultra-precision machining technology of large size optic is a comprehensive application of various sciences, which promotes the development for civil and national defense use.Under the processing of national optical project, our country makes great progress in this field.The development of ultra-precision machining technology for large size optic in micro/nano machining and measuring laboratory of Xiamen University is introduced, particularly in grinding equipment, grinding process, precise measuring, controlled bonnet polishing, environment monitoring, mid-spatial frequency error assessing and et al.From the requirement of the ultra-precision machining, the laboratory uses the experience of other countries for reference and integrates the above technology, then forms an intellectual property of grinding and polishing system independently for large size optic manufacture.国家自然科学基金(51075343;51275433); 国家科技重大专项(2011ZX04004-061;2013ZX04001000-206)资助项
加速溶剂萃取-液相色谱-串级质谱法测定近岸及河口沉积物中的拟除虫菊酯农药
A rapid and accurate method was developed for the measurement of 12 pyrethroid pesticides in estuarine and coastal sediments by accelerated solvent extraction (ASE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pyrethroid pesticides were extracted in 5.0 min and repeated one more time by ASE using mixed solvent of n-hexane and acetone(1:1, V/V) at 60 degrees C and pressure of 10.3 MPa with static extraction mode. After concentrated, the pesticides were separated with XDB-C-18 column with mobile phase of methanol and water containing 2.5 mmol/L ammonium acetate, and then determined with tandem mass spectrometer using positive ESI at MRM mode. Under the optimized conditions, relative standard deviation( RSD) for developed method was 1.1% 8.6% (20.0 mu g/kg, n = 8), standard added recoveries were 67.9% - 97.3%, and the limits of quantification(LOQ, 10 sigma) were 0.5 - 2.5 mu g/kg
牡蛎壳纳米羟基磷灰石的制备与表征
以僧帽牡蛎壳粉末为原料,通过水热反应合成纳米羟基磷灰石(n-HA),考察反应时间、反应温度、反应物摩尔比及牡蛎壳粉末的微结构对反应的影响.运用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线能谱仪(EDS)及MTT实验表征产物的晶相组成、形貌、化学组成及细胞相容性.结果显示,牡蛎壳粉末经水热反应后仍保持其原有形貌,产物为部分CO32-取代的片状n-HA,其Ca/P摩尔比约为1.5,其结构及组成与人骨HA相似,细胞相容性良好.牡蛎壳粉末外表面方解石通过溶解重结晶过程转化为片状n-HA,内部方解石则经由固态局部规整离子交换反应转化为n-HA.最佳水热反应条件为220℃下反应6 h,牡蛎壳中Ca与(NH4)2HPO4中P摩尔比为5∶6
性滥人群庚型肝炎病毒感染状况
目的:调查湖北地区性滥人群庚型肝炎病毒(HGV)感染状况。方法:检查309例有性滥史者的血清HGV感染标志物,用ELISA方法检测抗HGV。结果:309例性滥者HGV的感染率11.97%(37例),显著高于普通人群(1.51%,19/1257例)。女性HGV的感染率(12.36%,32/259例)与男性HGV的感染率(10%,5/50例)无显著差异。性滥时间大于2年者抗HGV阳性率17.05%(30/176例)显著高于性滥时间小于2年者5.26%(7/133例)。女性中有吸毒史者的HGV感染率(22.37%,17/76例)显著高于未吸毒者(8.20%,15/183例)。所有HGV感染者的肝功能正常。结论:性滥人群具有较高的HGV感染率,HGV可能通过性途径传播。性滥人群HGV的感染率与性滥时间呈正相关,吸毒增加了性滥者HGV感染的风险
Curcumin-induced Apoptosis Affects the Expression and Localization of hnRNP A2/B1 in Human Osteosarcoma MG-63 Cells
姜黄素(CurCuMIn)诱导处理的人成骨肉瘤Mg-63细胞,在光镜和电镜观察细胞凋亡的基础上,对HnrnP A2/b1在核基质中存在、分布及其与凋亡相关基因产物在Mg-63细胞中的共定位关系进行了研究.经姜黄素处理后,细胞出现染色质凝聚、细胞核固缩、凋亡小体等典型的细胞凋亡形态特征;双向凝胶电泳和质谱鉴定结果显示,HnrnP A2/b1存在于Mg-63细胞核基质蛋白组分中,在姜黄素处理后细胞核基质蛋白中表达下调.蛋白质印迹杂交结果,证实HnrnP A2/b1在姜黄素处理前后的Mg-63细胞核基质蛋白中的存在及其表达下调变化.免疫荧光显微镜观察显示,HnrnP A2/b1定位于Mg-63细胞核基质纤维上,经姜黄素处理后出现分布位置与表达水平变化.激光扫描共聚焦显微镜的观察结果显示,HnrnP A2/b1在Mg-63细胞凋亡过程中与bAX、bCl-2、fAS和P53等基因产物具有共定位关系,且其共定位区域发生了变化.研究结果证实了HnrnP A2/b1定位于核基质纤维上,是一种核基质蛋白,在姜黄素诱导人成骨肉瘤Mg-63凋亡过程中的表达与分布变化及其与凋亡相关基因的关系显然对Mg-63细胞凋亡具有重要影响,这为深入揭示肿瘤细胞凋亡的机制提供了重要科学依据和深入探索的新方向.The morphology of human osteosarcoma MG-63 cells under light microscopy and transmission election microscopy was altered when treated with curcumin.The distribution of heterogeneous nuclear ribonucleoprotein (hnRNP)A2 /B1 in the nuclear matrix and its colocalization with the apoptosis-related gene products were examined.The results demonstrated that curcumin induced typical apoptotic responses,such as chromatin agglutination,nuclei condensation,and apoptotic body formation.Twodimentional PAGE and mass spectrum analyses showed that hnRNP A2 /B1 was complexed with the nuclear matrix.Confirmed by Western blotting,curcumin treatment resulted in a down-regulation of hnRNP A2 /B1 expression.An altered distribution of hnRNP A2 /B1 with the nuclear matrix was observed in immunofluorescence assays.Laser confocal microscopy showed that hnRNP A2 /B1 colocalized with apoptosis-related molecules,including Bax,Bcl-2,Fas and p53,with different patterns before and after curcumin treatments.Our study showed that expression level and the distribution of hnRNP A2 /B1,a nuclear matrix protein,were altered by curcumin treatments and mought be involved in the process of apoptosis in MG-63 cells.国家自然科学基金项目(No.30871241)---
药瘾者庚型肝炎病毒感染状况及其影响因素
目的:调查湖北地区药瘾者HGV感染状况及其影响因素。方法:检查药瘾者的血清HGV感染指标,用ELISA法检测抗 HGV。结果:716例药瘾者HGV的感染率为12 . 85 % (92例)。静脉药瘾者抗 HGV阳性率为16 96% ,口服药瘾者为5 . 73 % ,两者比较差异有显著性意义(χ2 =10 8 .3 1,P 0 .0 5 ) ;3 45例女性药瘾者中卖淫者抗 HGV阳性率显著高于无卖淫史药瘾者(χ2 =4 10 ,P 0 . 0 5 ) ;抗 HCV (+ )者和抗 HCV (-)者的抗 HGV阳性率差异有显著性意义(χ2 =19 .2 6,P <0. 0 1)。所有HGV感染者的肝功能正常。结论:药瘾者具有较高的HGV感染率。药瘾者HGV感染率与吸毒时间呈正相关
湖北地区特殊人群庚型肝炎病毒感染状况及其影响因素
目的:调查湖北地区性滥者和药瘾者HGV感染状况及其影响因素。方法:检查药瘾者和性滥者的血清HGV感染指标,用ELISA法检测抗HGV。结果:2206例标本中普通健康体检者1257例;949例为特殊人群(药隐者716例,性滥者309例,其中76例既是药瘾者又是性滥者),其HGV感染率分别为12.85%(75/716)、11.97%(20/309)、22.37%(17/76),均显著高于普通人群(1.51%,19/1257)。药瘾和性滥2年以上者抗HGV阳性率(19.41%,17.05%)显著高于药瘾和性滥2年以下者(8.01%,5.26%;χ2分别为19.29和8.89,P0.05);抗HCV(+)者和抗HCV(-)者的抗HGV阳性率差异有显著性意义(χ2分别为19.26和4.25,P<0.05)。所有HGV感染者的肝功能正常。结论:药瘾者和性滥者均具有较高的HGV感染率。其HGV感染率与吸毒时间或性滥时间呈正相关
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