A multi-frequency inverse source problem

This paper is concerned with an inverse source problem that determines the source from measurements of the radiated fields away at multiple frequencies. Rigorous stability estimates are established when the background medium is homogeneous. It is shown that the ill-posedness of the inverse problem decreases as the frequency increases. Under some regularity assumptions on the source function, it is further proven that by increasing the frequency, the logarithmic stability converts to a linear one for the inverse source problem.     

Uncertain random data envelopment analysis for technical efficiency

Fuzzy Optimization and Decision Making - Data envelopment analysis (DEA) is a classical and prevailing tool for estimating relative efficiencies of multiple decision making units (DMUs). However,...     

On Necessary Optimality Conditions with Higher-Order Complementarity Slackness for Set-Valued Optimization Problems

Set-Valued and Variational Analysis - We aim to establish Karush-Kuhn-Tucker multiplier rules involving higher-order complementarity slackness under Hölder metric subregularity. These rules...     

Comparison of efficiency calibration techniques of HPGe detector for radioactivity measurement of soil sample in Marinelli geometry

Journal of Radioanalytical and Nuclear Chemistry - To keep the accredited category for the gamma spectrometry test in our laboratory, the efficiency curves of a HPGe detector for soil sample in...     

臭氧修饰(001)晶面TiO2纳米片及其光催化降解甲苯研究

本文系统研究了臭氧修饰对(001)主导晶面锐钛矿型TiO₂光催化剂降解甲苯性能的影响. 利用自行搭建的光催化VOCs降解装置对催化剂光降解甲苯的性能进行了测试. 通过多种表征手段,结合原位DRIFTS和DFT计算研究了臭氧表面修饰及甲苯吸附和降解机理. 结果表明,用臭氧进行表面修饰可以显著提高(001)主导晶面TiO₂光催化降解甲苯的性能. (001)晶面上丰富的5c-Ti不饱和配位是臭氧分子的吸附位点,其解离后形成的Ti-O键与H₂O分子结合,在表面生成大量孤立的Ti_5c-OH. Ti_5c-OH 是甲苯分子的吸附位,它的形成显著提高了对甲苯分子的吸附能力. 在光照下Ti_5c-OH与光生空穴结合能形成·OH自由基. 通过臭氧解离产生的O₂也可以与光生电子结合形成超氧自由基. 这些具有强氧化性活性自由基的形成促进了对气相甲苯的光催化降解速率.     

Gold-Catalyzed Amine Cascade Addition to Diyne-Ene: Enantioselective Synthesis of 1,2-Dihydropyridines

With the well-documented chemical and biological applications, piperidine and pyridine are among the most important N-heterocycles, and a new synthetic strategy, especially one with an alternative bond-forming design, is of general interest. Using the gold-catalyzed intermolecular condensation of amine and diyne-ene, we report herein the first example of enantioselective 1,2-dihydropyridine synthesis through a formal [3+2+1] fashion (up to 95 % yield, up to 99 % e.e.).     

Hemin-Promoted Direct C−H Thiolation in the Synthesis of Diaryl Sulfides

Diaryl sulfides are a class of important synthetic chemical units. Herein, we report a new method for direct preparation of diphenyl sulfides using P-toluenesulfonyl chloride as an effective thiophenyl radical precursor with assistance from Hemin. Various substituted anisoles and benzenesulfonyl chlorides are well tolerated, resulting in moderate to good yields of diaryl sulfides. The potential of the proposed method is validated by good yields obtained in gram scale reactions.     

氯氧化镁在水中的溶解行为

用ｐＨ法和氯电位法测定氯氧化镁不同温度下在水中的溶解过程。一定间隔时间分析液样中的Ｍｇ＾２＋、Ｃｌ＾－、ＯＨ＾－的浓度，用物化方法鉴定固相。得出不同温度下的相转化、溶解的Ｃ￣ｔ曲线及动力学方程。计算了它们的Ｋｓｐ和热力学函数。     

LaDAIY型沸石的裂解活性和抗氮性能

采用脉冲微反技术,以含吡啶的正庚烷为原料,考察了LaDAlY型沸石的裂解和抗氮性能。结果表明,LaDAlY型沸石的裂解与抗氮性能均优于其母体样品DAlY。结合NH_3-TPD的数据,讨论了酸性与裂解和抗氮性能之间的关系,对吡啶中毒的机理进行了探讨。     

Structure elucidation and NMR assignments of a new 6,9-cyclotetrahydrofuranlignan from Syringa pinnatifolia

A new 6,9-cyclotetrahydrofuranlignan, 3,3′-dimethoxy-4,4′-dihydroxy-8β,9β,8′α-6,9-cyclotetrahydrofuranlignan, was isolated from the stem of Syringa pinnatifolia Hems1.var. alashanensis MA. et S. Q. ZHOU. Its structures were elucidated on the basis of spectroscopic methods including UV, IR, ESI-MS, 1D NMR and 2D NMR.