不同B,Al分布对ZSM-5分子筛的甲醇制丙烯反应性能的影响

本文设计了两个系列的硼改性ZSM-5分子筛:一步法合成的B-Al-ZSM-5系列分子筛和两步法合成的Al-ZSM-5@BZSM-5核壳分子筛。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、扫描透射电子显微镜面扫(STEM mapping)、N——2物理吸附脱附、氨气程序升温脱附(NH3-TPD)、1,3,5-三异丙基苯(TIPB)裂解等表征发现,两个系列的样品中B1-Al-ZSM-5和Al@B1-ZSM-5,B2-Al-ZSM-5和Al@B2-ZSM-5以及B3-Al-ZSM-5和Al@B3-ZSM-5分别具有相似的织构性质、强弱酸量、酸强度和比例,以及不同的B、Al元素分布和酸分布。我们用这两个系列样品对比研究不同的强弱酸分布-强弱酸均匀分布和梯度分布对甲醇制丙烯(MTP)反应性能的影响。通过研究发现,强弱酸均匀分布的样品具有更高的丙烯选择性,归因于更低的整体强弱酸密度;而强弱酸梯度分布的样品具有更长的MTP反应寿命,归因于外表面上更低的强酸密度和更高的弱酸密度。     

30K～60K温区混合工质内复叠节流制冷循环及其实验验证

本文提出了利用内复叠节流制冷循环获得３０Ｋ－６０Ｋ温区的新制冷方案。进行了与之相关的热力学问题分析，建立了实验装置，首次获得了５０Ｋ左右的低温。     

吸附势理论在活性炭对氙的吸附平衡研究中的应用

实验测定了吸附温度为20℃、30℃、50℃时氙在活性炭上的吸附平衡数据。应用吸附势理论建立了20℃下氙在活性炭上的吸附特性曲线。运用该特性曲线计算了30℃、50℃下的吸附平衡数据,并与实验值进行了比较,计算值与实验值符合较好。结果表明,应用吸附势理论可以较好地预测活性炭对氙的吸附平衡。     

Structural Design and Property Characterization of Bi-functional Photorefractive Polymer

lntroductionThedrivingforcet0pursueresearchonph0t0refractivep0Iymersc0mesfr0mb0thfundamentaIinterestsandpracticalexpectati0ns.Ithasbeenkn0wnthatph0t0refractivematerialsaremultifuncti0nalmateriaIswhichcombinetheelectr0-0ptic(EO)effectandphotoconductivitytomanifestanewpropertyfphotorefractivity'.Sincel990,photorefractivestudieshavebeenextendedintoorganicmaterialsfbothd0pedorganiccrystalsandpolymericmaterials=-'.Organicphotorefractivematerialsexhibitreasonablylargeelectr0-opticresp0nseandalower…     

若干新型微纳光子学器件研究

光子晶体和纳米光纤是两种重要的微纳光子学材料,各自具有非常独特的控制光子传输状态的功能,是研究微纳尺度下光与物质相互作用的重要平台,也是实现新型微纳光子学器件的重要基础.文章简要介绍了超快速低功率光子晶体全光开关、纳米光纤传感器、干涉器和介质-金属纳米线复合结构器件的研究进展.     

基于QuEChERS-高效液相色谱－串联质谱法检测八角中莽草毒素的研究

该文建立了八角中莽草毒素的高效液相色谱－串联质谱检测方法。样品在乙酸盐缓冲体系下经乙腈溶液提取,200 mg N-丙基乙二胺（PSA）和50 mg石墨化碳黑（GCB）净化后,使用Accucore aQ C18（2.1 mm × 150 mm,2.6 μm）柱分离,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,采用电喷雾离子源负离子模式（ESI－）及多反应监测模式（MRM）进行测定,外标法定量。结果显示,莽草毒素在1.0 ~ 100.0 ng/mL范围内线性关系良好,相关系数（r2）大于0.99。样品在0.02、0.20、0.40、1.00 mg/kg加标水平下的平均回收率为92.5% ~ 112%,相对标准偏差（RSD,n = 6）为1.1% ~ 6.0%,检出限和定量下限分别为0.006 mg/kg和0.02 mg/kg。用于市售八角中莽草毒素含量的测定,10份样品中有1份莽草毒素含量超过1.00 mg/kg。该方法简便、快速、灵敏、准确,可为八角的质量评价与真伪鉴别提供技术支撑。     

Deciphering In-vivo Cross-linking Mass Spectrometry Data for Dynamic Protein Structure Analysis

Protein structure and protein-protein interactions(PPIs) are crucial for regulating cellular activities required for cell viability and homeostasis. Chemical cross-linking coupled with mass spectrometry(CXMS) has become a versatile tool providing insights into both protein structure with distance restraints and protein-protein interactions with interface sites. Cross-links as the most information-rich data in a CXMS experiment are responsible for the structural model validation and integrative modeling with high throughput and sensitivity. In this work, ensemble refinement of the existing protein structure against the in-vivo cross-linking distance restraints was performed for dynamic protein structure modeling and protein interaction binding interface building in the intracellular environment. These results indicate great potential of in-vivo CXMS data for providing a molecular basis of protein structural dynamics exploration and function performance.     

基于纹理特征的挠性印制电路板焊盘缺陷检测

纹理特征反应了物体表面微观几何形貌与颜色的波动程度。针对挠性印制电路(FPC)焊盘纹理特征的提取与检测,本文提出基于灰度与纹理梯度二维分布特征的方法建立描述纹理特征的熵统计量,该统计量能够灵敏地反映、量化焊盘金面正常或异常情况下的不同表面视觉特征,当用于缺陷检测时,可准确地识别出焊盘缺陷,检测准确率高达96.7%,50个焊盘的平均检测时间为300ms,满足在线检测的要求。     

Directionally enhanced probe for side‐illumination Tip enhanced spectroscopy

We investigate the high performance of an apertureless near‐field probe consisting of a tapered metal tip with periodic shallow surface grooves. The spontaneous emission of a single emitter near the apex is systematically analyzed for side‐illumination tip enhanced spectroscopy scheme. In contrast to a conventional bare tapered tip, the corrugated probe not only strongly enhances the local excitation field, but also modulates the emission directivity, leading to high collection efficiency and signal‐to‐noise ratio. Specifically, we propose that an asymmetric tip enhanced spectroscopy probe containing two different length nanorods at the apex realizes unidirectional emissions. The radiation pattern is sensitive to the emission wavelengths and the emitter positions, which can increase the signal‐to‐noise ratio through suppression of the undesired signal. The proposed asymmetrical corrugated probe possesses a wide range of potential applications, including increasing the detection efficiency of tip enhanced spectroscopy at the single molecule level. Copyright © 2016 John Wiley & Sons, Ltd.     

Fe/CexZr0.9-xLa0.1O1.95-Al2O3 整体式催化剂上的甲烷催化燃烧反应

 采用共沉淀法制备了一系列 CexZr0.9-xLa0.1O1.95-Al2O3 储氧材料 (其中 CexZr0.9-xLa0.1O1.95 与 Al2O3 的质量比为 1; x = 0, 0.3, 0.5, 0.7 和 0.9), 以其为载体, 制备了一系列负载铁基整体式催化剂. 考察了该系列催化剂催化甲烷燃烧反应性能, 并用低温 N2 吸附-脱附、储氧能力测试、X 射线衍射和 H2 程序升温还原等手段对载体和催化剂进行了表征. 活性测试结果表明, 当 x = 0.7 时, 催化剂活性最高, 可在 V(CH4) = 1% 和 50 000 h1 条件下使甲烷 465 oC 起燃, 615 oC 完全转化. CexZr0.9-xLa0.1O1.95-Al2O3 样品同时具有较高的储氧能力、较高的比表面积和抗热老化能力. 当 x = 0.5 和 0.7 时, 催化剂载体以 CeZrLaAlO 固溶体存在, 抗老化能力最好, 且 x = 0.7 时, 催化剂最易被还原.