一种光纤SPR传感器光谱降噪的新方法

根据光纤SPR传感器光谱的特点和实验系统的实时性监测要求,提出了一种新的降噪方法--移动小波提升算法.该方法脱离傅里叶变换,将复杂滤波过程分解为若干可逆简单过程,处理快而准,无须额外内存.在共振波长为557.70 nm的理论光谱上加一定强度的高斯白噪声,得到了仿真光谱模型.分别用基于Haar,CDF(3.1),DD(4,2)和5/3小波的移动小波提升算法对此模型进行降噪,得到共振波长分别为556.45,564.06,557.27和557.91 nm.最后一种算法相对误差最小,仅0.037 7%.这比用经证实降噪效果较好的symletll小波降噪法得到的0.043 03%更低.不同时刻采集同一检测系统的多组光谱,其共振波长标准偏差为4.186 7 nm,经新算法降噪后降为1.560 8 nm,也优于symlet11小波降噪法的2.725 3 nm,研究表明,用移动小波提升算法降噪有效抑制了系统噪声,减小了噪声对检测共振波长的影响,保证了光纤SPR传感器的检测精度.     

The synthesis of bis(fulvalene)dicobalt hexafluorophosphate [(h5:h5′-C10H8)2 CoIII2][PF6]2

The organometallic compounds (Ph₃P)AuC(OMe)=NAr and [(EtO)(ArN=)C]₂ Hg can act as monodentate or as balentate ligand, respectively, towards another, different emtal atom (e.g. Ag and Rh).     

XPS evidence for band bending at semiconducting oxide surfaces

The magnitude of the surface potential, directly influenced by defect properties and donor or acceptor chemisorption, has been studied using XPS for p-type nickel oxide surfaces. Above 200 W, the KE shifts are independent of X-ray intensity. A simple explanation of the dependence of the surface potential (V_ch) on band bending (V_s) is proposed with preliminary experimental evidence allowing derivation of values of V_s.     

Apollonian structure in the Abelian sandpile

The Abelian sandpile process evolves configurations of chips on the integer lattice by toppling any vertex with at least 4 chips, distributing one of its chips to each of its 4 neighbors. When begun from a large stack of chips, the terminal state of the sandpile has a curious fractal structure which has remained unexplained. Using a characterization of the quadratic growths attainable by integer-superharmonic functions, we prove that the sandpile PDE recently shown to characterize the scaling limit of the sandpile admits certain fractal solutions, giving a precise mathematical perspective on the fractal nature of the sandpile.     

Solubility of chelating agents and metal-containing compounds in supercritical fluid carbon dioxide

The solubility of 49 metal-containing compounds and 15 "free" ligands in supercritical fluid carbon dioxide is reviewed. Solubilities were found to range over eight orders of magnitude, with the highest value of solubility being 56 g l(-1). Metals complexed with fluorine substituted ligands were found to be the most soluble, and metals complexed with phenyl-substituted ligands the least soluble. A general trend for increasing solubility with increasing oxidation state is observed and this is correlated with the increased number of coordinating ligands protecting the metal center from interaction with the supercritical fluid and also due to the increased number of solvation interactions with the increased number of ligand groups.     

o-Nitrobenzylidene compounds. I—Competitive ortho interactions in the mass spectra of n-o-nitrobenzylidene-o-substituted anilines

The intense [M – 17]⁺ ion, which is a characteristic feature of the mass spectra of N-o-nitrobenzylideneaniline and its simple derivatives, may be substantially reduced in intensity when the aniline-derived ring is also ortho substituted: the intensity is lowest when this ortho substituent has a nucleophilic character and can itself interact with the CH?N group. The ortho substituents examined are Br, CH₃, OH, NH₂, SH, SC₆H₄CH₃(p), CO₂CH₃ and CO₂C₂H₅.     

Performance optimization of hollow fiber reverse osmosis membranes. Part II. Comparative study of flow configurations

Sensitivity evaluation of overall performance of hollow fiber membranes was performed to study the effects of such operating parameters as pressure, packing density, and fiber diameter. It is shown that in a wide range of operating conditions, fiber productivity and selectivity as dependent upon hollow fiber length exhibit a similarity property. This is demonstrated in all three flow configurations of concurrent, countercurrent, and flow inside hollow fibers.