基于试验设计的膨胀型钢结构防火涂料配方的多变量分析(英文)

膨胀型防火涂料的配方优化,需要阻燃剂之间有效的协同作用来获得防火效果。以ISO耐火测试标准为依据,对以聚磷酸铵、季戊四醇和三聚氰胺阻燃剂为主要成分的防火涂料,利用D-优化设计原理,借助Design Expert软件进行试验设计,在有限的试验次数基础上,运用MODDE软件对试验结果进行了多变量回归分析,获得了满意的试验结果。     

Cu的加入对Fe3Si材料在NaCl溶液中的腐蚀行为的影响

以原子比为3：1的Fe粉和Si粉球磨20h后,将球磨得到的Fe（si）粉末和混合了质量分数为5％Cu的Fe（Si）-Cu粉末,在1O00±30℃,20MPa的压力下通过热压烧结的方法制备了Fe3Si和Fe3Si--Cu复合材料。文章通过浸泡腐蚀和电化学腐蚀两种方法讨论了Fe3Si和Fe3Si--5％Cu复合材料在NaCl溶液中的腐蚀行为。实验表明,两种材料在NaCl溶液中的腐蚀过程都是活化过程,Fe3Si在不同摩尔浓度的NaCl溶液中的腐蚀性能要比Fe3Si-5％Cu要好,浸泡腐蚀速率要小,自腐蚀电流也小。     

旋转线圈测量法测量BEPCⅡ对撞区超导磁铁磁场

北京正负电子对撞机二期工程(BEPCⅡ)中的超导磁铁用来提高BEPCⅡ的对撞亮度,并对闭轨和耦合进行校正。超导磁铁要尽可能靠近对撞点(IP),并浸泡在1.0T的探测器BESⅢ螺线管磁场中。对撞点两侧各有1块超导磁铁,每块都包含有聚焦磁铁SCQ、水平偏转磁铁SCB/HDC、垂直校正子VDC、斜四极子SKQ及反螺线管AS等功能磁铁。利用旋转线圈的测量方法对SCQ、SCB/HDC、VDC、SKQ等进行测量,了解其积分场、高次谐波及沿束流运行方向的局部磁场。通过与BNL在垂直杜瓦中的测量结果进行的比较可知,高次谐波测量结果差别不大;与张力线的比较可知,SCQ及SCB的主极矩偏差小于3×10-3。表明提出的计算方法可进行磁场的绝对测量。     

Effect of Tb/Mg doping on composition and physical properties of hydroxyapatite nanoparticles for gene vector application

Transfection efficiency of hydroxyapatite nanoparticles (HAnps) is relative to the particle size, morphology, surface charge, surface modifier and so on. This study prepared HAnps with doped Tb/Mg by hydrothermal synthesis method (HTSM) and investigated the effects of different Tb/Mg contents on the morphology, particle size, surface charge, composition and cellular endocytosis of HAnps. The results showed that Mg-HAnps possessed better dispersion ability than Tb-HAnps. With increasing doping content of Tb/Mg-HAnps, the granularity of Tb-HAnps increased, while that of Mg-HAnps declined. Both particle size and zeta potential of Mg-HAnps were lower than those of Tb-HAnps. 7.5% Mg-doping HAnps presented relatively uniform slender rod morphology with average size of 30 nm, while 10% Mg-doping HAnps were prone to agglomeration. Moreover, Mg-HAnps-GFP (green fluorescent protein) endocytosed by MG63 cells was dotted in the perinuclear region, while Tb-HAnps were more likely to aggregate. In conclusion, as gene vectors, Mg-HAnps showed enhanced properties compared to Tb-HAnps.     

基于LabVIEW的齿轮箱故障诊断系统设计

介绍了利用虚拟仪器技术进行齿轮箱故障诊断系统设计的原理和方法。硬件系统由加速度传感器、信号调理卡、数据采集卡和PC机组成。以LabVIEW为平台设计了界面友好的软件系统,采用"小波去噪+EEMD分解"的非平稳信号处理方法进行故障信号的特征提取。运行结果表明,该系统能快速准确地对齿轮箱故障进行诊断,具有良好的应用前景。     

Design and Fabrication of AlGaN-Based Resonant-Cavity-Enhanced p-i-n UV PDs

AlGaN-based resonant-cavity-enhanced (RCE) p-i-n photodetectors (PDs) for operating at the wavelength of 330 nm were designed and fabricated. A 20.5-pair AlN/Al_0.3Ga_0.7N distributed Bragg reflector (DBR) was used as the back mirror and a 3-pair AlN/Al_0.3Ga_0.7N DBR as the front one. In the cavity is a p-GaN/i-GaN/n-Al_0.3Ga_0.7N structure. The optical absorption of the RCE PD structure is at most 59.8% deduced from reflectance measurement. Selectively enhanced by the cavity effect, a response peak of 0.128 A/W at 330 nm with a half-peak breadth of 5.5 nm was obtained under zero bias. The peak wavelength shifted 15 nm with the incident angle of light increasing from 0deg to 60deg.