X波段阶梯阻抗微带带通滤波器设计

设计了一款X波段的多模带通滤波器,并给出了仿真与实验结果。采用恒定阻抗枝节加载3个阶梯阻抗枝节的方式,构成滤波器的主体;利用表面电流分布图获得影响带内极点分布的枝节参数,通过调整阶梯阻抗枝节参数优化滤波性能。为实现更好的带外抑制能力,滤波器两端各串联一对平行耦合线,在14 GHz引入一个传输零点。实验测试结果显示,所设计滤波器的中心频率为9.76 GHz,带宽为2.4 GHz,30 dB/3 dB矩形系数为1.63,相对带宽为25%,带内插入损耗大部分小于1 dB,大部分回波损耗高于15 dB,与仿真结果较为吻合。国家自然科学基金资助项目(61601393);;福建省自然科学基金资助项目(2016J01321);;极高频复杂系统国防重点学科实验室开发基金资助项

压电驱动MEMS光学扫描镜的研制

<span>为实现高速大角度光学扫描,研制了一种新型压电陶瓷驱动MEMS光学扫描镜.将两块压电陶瓷分别放置在扫描镜背面两侧作为驱动,通过简单的扭转梁结构把两块压电陶瓷沿相反方向上下振动转换成镜片的扭转振动.采用MEMS体硅工艺及微装配技术,制备出器件样品.经测试,大气压下,研制出的扫描镜扫描谐振频率可达21.9 kHz,施加200 V交流电,谐振态的光学扫描角度为21.8&deg;.测试数据表明该器件适用于激光打印、条形码扫描及微型激光投影显示等领域.&nbsp;</span><span><a id="ChDivSummaryMore" style="display: none">更多</a><a id="ChDivSummaryReset" style="display: none">还原</a></span

液相色谱-质谱用于卵巢肿瘤中磷脂轮廓的分析

卵巢肿瘤日益影响女性的健康和生活质量,其中的卵巢癌是女性三大恶性肿瘤之一,死亡率高居三者之首。因此卵巢肿瘤尤其卵巢癌是目前的一个研究热点。本研究利用液相色谱-质谱（LC-MS）联用技术对卵巢肿瘤进行磷脂轮廓分析,研究良性卵巢肿瘤（B）和卵巢癌（M）的患者血清中磷脂代谢的差异情况。首先用LC-MS采集血清中磷脂的指纹图谱,通过峰识别、峰匹配等得到峰表,然后利用正交校正的偏最小二乘法（OSC-PLS）进行多种分型,根据模型的变量重要因子（VIP）、VIP值的置信区间、S图和显著性差异检验结果等筛选有差异的磷脂。结果显示：M组和B组与正常对照（N）组比较都存在明显的磷脂代谢差异,发生改变的磷脂主要为缩醛磷脂酰乙醇胺、磷脂酰胆碱、缩醛磷脂酰胆碱、鞘磷脂和溶血磷脂酰胆碱

Pt负载于不同载体对蓖麻籽油加氢催化制备生物航油的影响Catalytic hydrogenation of castor oil to prepare bio-aviation kerosene by Pt loaded on different carriers

以蓖麻籽油为原料，在Pt负载于不同载体构建的系列催化剂催化作用下，在高温高压反应釜中开展一步加氢催化制备生物航油研究。采用等体积浸渍法制备了Pt基系列催化剂，探究了氢压、反应时间、反应转速、反应温度对催化反应效果的影响。结果表明，加氢催化制备生物航油的最佳反应条件为：氢压4 MPa，反应时间7 h，催化剂Pt/SAPO-11、Pt/ZSM-23反应转速均为1 100 r/min，催化剂Pt/SBA-15反应转速为1 000 r/min，催化剂Pt/SAPO-11和Pt/ZSM-23反应温度均为360 ℃，催化剂Pt/SBA-15反应温度为340 ℃。在最佳条件下，催化剂Pt/SAPO-11的转化率为90.79%，C8～C16烷烃选择性为45.86%，C8～C16烷烃异构率为9.87%；催化剂Pt/ZSM-23的转化率为91.04%，C8～C16烷烃选择性为56.98%，C8～C16烷烃异构率为12.11%；催化剂Pt/SBA-15的转化率为46.26%，C8～C16烷烃选择性为12.85%，C8～C16烷烃异构率为4.83%。实验表明，Pt/ZSM-23的3项指标均优于Pt/SAPO-11和Pt/SBA-15，其更适合用于催化制备生物航油。 Using castor oil as a raw material, under the action of a series of catalysts constructed with Pt loaded on different carriers, the one step catalytic hydrogenation to prepare bio-aviation kerosene in a high-temperature and high-pressure reactor was researched. The Pt-based series catalysts were prepared by equal volume impregnation. The influences of hydrogen pressure, reaction temperature, reaction time, and stirring speed on the catalytic effect were explored. The results showed that the optimal preparation conditions of bio-aviation kerosene were obtained as follows: hydrogen pressure 4 MPa, reaction time 7 h, stirring speed 1 100 r/min for Pt/SAPO-11 and Pt/ZSM-23, 1 000 r/min for Pt/SBA-15, reaction temperature 360 ℃ for Pt/SAPO-11 and Pt/ZSM-23, and 340 ℃ for Pt/SBA-15.Under the optimal conditions, the conversion rate, selectivity of C8-C16 alkanes and isomerization rate of C8-C16 alkanes of Pt/SAPO-11 were 90.79%, 45.86% and 9.87% respectively; the conversion rate, selectivity of C8-C16 alkanes and isomerization rate of C8-C16 alkanes of Pt/ZSM-23 were 91.04%, 56.98%, and 12.11%, respectively; the conversion rate,selectivity of C8-C16 alkanes and isomerization rate of C8-C16 alkanes of Pt/SBA-15 were 46.26%, 12.85% and 4.83%, respectively.The research indicated that the three indexes of Pt/ZSM-23 were superior to Pt/SAPO-11 and Pt/SBA-15, and it was more suitable for the preparation of bio-aviation kerosene

Comprehensive thermal characterization using ruby R fluorescence lines of sapphire and GaNE2-high Raman mode from Raman spectra in high-power flip-chip InGaN/GaN LEDs

<p>A comprehensive temperature characterization method based on the GaNE2-high Raman mode and sapphire ruby R fluorescence lines from Raman spectra was developed to analyse the thermal distribution and heat transfer process of high-power flip-chip InGaN/GaN LEDs (FC LEDs). Our analysis demonstrated that in addition to the known problem that the edges of mesa were always the hottest point of FC LEDs, which was due to the current crowding effect, a noteworthy temperature difference was first observed between the sapphire substrate and n-GaN when the injection current was above 300 mA. A 'heat reservoir' was suggested to occur at the interface between the sapphire and n-GaN due to poor thermal conductivity of sapphire when a large amount of heat from the hottest spot cannot be effectively transferred to the Si mount via the active region under high injection currents. </p