Laser Zone Melting and microstructure of waveguide coatings obtained on soda-lime glass

This study presents a Laser Zone Melting method with potential for producing planar waveguides at large scale, based on the surface coupling of two chemically compatible glass layers which exhibit distinct indices of refraction. The method is based on a recent patent, particularly applicable to process glass and ceramics with low thermal shock resistance. Glass coatings containing 76.24% by weight PbO are thus here reported, as obtained by this method on commercial soda-lime planar glass substrates. Their higher indices of refraction (1.58 vs 1.52 for commercial soda-lime glass) result in attractive waveguiding potential, as demonstrated with measurements using focused light from a He-Ne laser beam. Scanning and transmission electron microscopy studies reveal excellent integration and compatibility between the observed coatings and substrates, where diffusion in the proximity of the interface was studied by EDS analysis. Crystalline phases have not been found within the coating, or within the substrate, as concluded from the absence of Bragg-peaks in XRD experiments.     

加拿大白桦地致密气储层定量表征技术

以加拿大白桦地大型致密砂岩气田的研究为基础,梳理了致密气开发过程中需要评价分析的5大品质特性,提出了表征致密气储层特征的关键参数,确定了适用研究区的致密气储层定量表征和评价技术,形成了一套指标体系:多旋回精细等时地层格架和砂体叠置结构特征分析技术以确定储层空间展布;TOC测井参数地质统计定量技术以确定有机质丰度;岩心"四性"关系标定与序贯高斯模拟的储层物性定量表征技术以确定储层物性分类级别;基于岩心应力实验和测井解释的岩石脆性指数综合判定技术以确定岩石可压性;与压裂水平井产量相关的多参数组合综合评价技术以确定有利布井区;井下微地震监测技术定量用以表征人工裂缝、优化井位部署;水平井分段压裂优化技术确定最佳压裂段数、缝间距等参数,落实分段压裂水平井单井控制体积,确定单井控制储量。通过储层和裂缝综合研究不断优化致密气藏开发井网,其中大规模水平井压裂是致密气高产的有效保障,这些技术的现场应用也取得了显著的效果。     

Analysis for surface coke deposition in used Mo-Co/γ-Al2O3 catalyst for diesel hydrodesulfurization

The coked Mo-Co/γ-Al₂O₃ catalysts were Soxhlet extracted with the solvent of tetrahydrofuran. Experimental techniques like FT-IR, GC-MS, XPS, H₂-TPR, BET, etc. were applied for the characterization of coke and catalysts to make a comparison of their physical properties. The results showed that the active components of the catalyst were slightly less after the reaction. The specific surface area and the pore volume had recovered to some degree. These results indicated that the main cause of deactivation of Mo-Co/γ-Al₂O₃ catalysts is carbon deposit. The principal components of the soluble carbon deposit on Mo-Co/γ-Al₂O₃ catalysts were alkyl aromatics with 1–4 rings and C₁₉–C₂₉ long-chain alkane compounds.     

Combined Experimental and Computational Methods Reveal the Evolution of Buried Interfaces during Synthesis of Ferroelectric Thin Films

Understanding interfaces between dissimilar materials is crucial to the development of modern technologies, for example, semiconductor–dielectric and thermoelectric–semiconductor interfaces in emerging electronic devices. However, the structural characterization of buried interfaces is challenging because many measurement techniques are surface sensitive by design. When interested in interface evolution during synthesis, the experimental challenges multiply and often necessitate in situ techniques. For solution‐derived lead zirconate titanate (PZT) ferroelectric thin films, the evolution of buried interfaces during synthesis (including dielectric–metal and metal–metal) is thought to dramatically influence the resultant dielectric and ferroelectric properties. In the present work, multiple experimental and computational methods are combined to characterize interface evolution during synthesis of ferroelectric PZT films on platinized Si wafers—including in situ X‐ray diffraction during thermal treatment, aberration‐corrected scanning transmission electron microscopy of samples quenched from various synthesis states, and calculations using density functional theory. Substantial interactions at buried interfaces in the PZT/Pt/Ti/SiO _x /Si heterostructure are observed and discussed relative to their role(s) in the synthesis process. The results prove that perovskite PZT nucleates directly from the platinum (111)‐oriented bottom electrode and reveal the roles of Pb and O diffusion and intermetallic Pt₃Pb and Pt₃Ti phases.     

地域性建筑创作的场所表达——南阳新闻中心总体布局设计探析

南阳新闻中心是"南都"南阳新区发展的重要区域,该文力求从地域性建筑创作思想出发,从自然因素、场地环境、人文因素、情感回应等几方面探讨地域性的场所表达方法。结合地段的地域特征,从南北交汇、"双蛋黄结构"、白河景观、显山理水、细部隐喻、两衙文化等角度,剖析南阳新闻中心总体布局设计的双轴体系,全方面展现南阳新闻中心规划设计创作实践过程中的地域性场所表达方法和手段,探索了反映特定地点与文化的地域性建筑创作思路,营造了富有地域特色、饱含场所精神的城市空间。     

沸石分子筛表面酸性表征与研究进展

作为固体酸,沸石分子筛是重要的石油炼制与化工催化剂,表面酸性的数量、类型以及强度等决定其催化性能。表征与研究沸石分子筛表面酸性对于设计和开发高性能沸石分子筛催化剂意义重大。沸石分子筛表面酸性表征方法主要有吸附指示剂滴定法、程序升温脱附法、核磁共振法和红外光谱法等。以沸石分子筛表面酸性表征方法为主线,综述近年来对沸石分子筛表面酸性的表征与研究进展,重点介绍红外光谱法在沸石分子筛表面酸性表征与研究中的应用。指出通过对沸石分子筛表面酸性进行表征,将获得的表面酸性与其相应的催化性能关联,从反应机理理解并建立分子筛表面酸性与催化性能之间的关系将是今后的研究重点。     

Dielectric properties of porous silicon for use as a substrate for the on-chip integration of millimeter-wave devices in the frequency range 140 to 210?GHz

In this work, the dielectric properties of porous Si for its use as a local substrate material for the integration on the Si wafer of millimeter-wave devices were investigated in the frequency range 140 to 210 GHz. Broadband electrical characterization of coplanar waveguide transmission lines (CPW TLines), formed on the porous Si layer, was used in this respect. It was shown that the dielectric parameters of porous Si (dielectric permittivity and loss tangent) in the above frequency range have values similar to those obtained at lower frequencies (1 to 40 GHz). More specifically, for the samples used, the obtained values were approximately 3.12 ± 0.05 and 0.023 ± 0.005, respectively. Finally, a comparison was made between the performance of the CPW TLines on a 150-μm-thick porous Si layer and on three other radiofrequency (RF) substrates, namely, on trap-rich high-resistivity Si (trap-rich HR Si), on a standard complementary metal-oxide-semiconductor (CMOS) Si wafer (p-type, resistivity 1 to 10 Ω.cm) and on quartz.

PACS

84.40.-x; 77.22.Ch; 81.05.Rm     

3-(2,6-二氯苯基)-5-(1-吡咯烷酮基)-2,3-异唑啉的合成及抑菌活性研究

以2,6-二氯苯甲醛为原料,与盐酸羟胺反应生成2,6-二氯苯甲醛肟,经氯代得到氯代2,6-二氯苯甲醛肟,再和N-乙烯基吡咯烷酮进行1,3-偶极环加成反应,合成了3-(2,6-二氯苯基)-5-(1-吡咯烷酮基)-2,3-异唑啉。其结构经1 HNMR、13 CNMR及高分辨质谱表征。初步的离体生物活性测试结果表明,该异唑啉化合物对供试菌种普遍具有抑制作用,并且对水稻纹枯病菌的抑制率达到了95.8%。     

基于铁路客站商业开发视角的现场调查及设计探索

铁路客站的商业开发已是必然趋势。本文基于对多个建成铁路客站的现状和存在问题的现场调研,结合铁路商业项目的需求,根据铁路的管理特点,提出若干铁路客站设计方面的可行性建议。