General Shrinkage Rule with Respect to gamma-Norms for Bridge Estimation

Bridge regression, a special family of penalized regressions of a penalty function  with , has been studied in many literatures. In this paper, we provide some theoretical results of how the shrinkage rule changing with  under two settings:  and , respectively. Simulation results are conducted to evaluate the performance of the proposed method.     

Hardness of lazy packing and covering

We prove APX-hardness for the two problems maximum resource bin packing and lazy bin covering. Simple algorithms matching the best absolute bounds under the assumption P≠NP are also derived.     

Ultrafast folding of a computationally designed Trp-cage mutant: Trp2-cage

Miniproteins provide useful model systems for understanding the principles of protein folding and design. These proteins also serve as useful test cases for theories of protein folding, and their small size and ultrafast folding kinetics put them in a regime of size and time scales that is now becoming accessible to molecular dynamics simulations. Previous estimates have suggested the "speed limit" for folding is on the order of 1 mus. Here a computationally designed mutant of the 20-residue Trp-cage miniprotein, Trp2-cage, is presented. The Trp2-cage has greater stability than the parent and folds on the ultrafast time scale of 1 mICROs at room temperature, as determined from infrared temperature-jump experiments.     

Superparamagnetic lysozyme surface-imprinted polymer prepared by atom transfer radical polymerization and its application for protein separation

Molecular imprinting as a promising and facile separation technique has received much attention because of their high selectivity for target molecules. In this study, the superparamagnetic lysozyme surface-imprinted polymer was prepared by a novel fabricating protocol, the grafting of the imprinted polymer on magnetic particles in aqueous media was done by atom transfer radical polymerization (ATRP), and the properties of the imprinted polymer were characterized in detail. Its high selective adsorption and recognition to lysozyme demonstrated the separation ability of the magnetic imprinted material to template molecule, and it has been used for quick and direct separation of lysozyme from the mixture of standard proteins and real egg white samples under an external magnetic field. Furthermore, the elution of lysozyme from the imprinted material was achieved by PEG/sulphate aqueous two-phase system, which caused lysozyme not only desorption from the imprinted materials but also redistribution in the top and bottom phase of aqueous two-phase system. The aqueous two-phase system exhibited some of the extraction and enrichment effect to desorbed lysozyme. Our results showed that ATRP is a promising method for the protein molecularly imprinted polymer preparation.     

Morphology-controlled synthesis and characterization of urchin-like CdS and nanowire

Novel urchin-like CdS was synthesized via a facile solvothermal route without any assistant agent. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, high-resolution transmission electron, and photoluminescence spectrophotometer. Based on time-resolved experiments, a possible growth mechanism of 3D urchin-like CdS microspheres was initially proposed. Furthermore, morphology control of CdS was achieved by adjusting the quantity addition of TGA to obtain the 1D CdS nanowires.     

Abnormal Fluorescence Behavior of Pyrene Functionalized Chitosan Films to Some Quenchers

Investigation of the fluorescence behavior of a pyrene functionalized chitosan film (PSC-CS) to some quenchers,including KI,CH3NO2 and Cu(NO3)2,has revealed that the monomer emission from the PSC-CS film increased rather than decreased,whereas the excimer emission decreased with the increase of time of duration after addition of KI or Cu(NO3)2.Both the increasing and decreasing processes could last as long as 20min to 40min,Unlike that observed in the system containing KI or Cu(NO3)2,for CH3NO2 system,both the monomer emission and the excimer emission increased with introduction of the quencher,but the excimer emission only started to increase after an hour-long induction period.The position of the excimer emission of the PSC-CS film did not change very much with addition of KI or Cu(NO3)2.However,addition of CH3NO2 made the excimer emission blue shifted for at least 20nm indicating formation of distorted excimers opr partially overlapped excimers.The fluorescence response of the film to external additions is sensitive but is low in selectivity.This property may make the film use as a novel sensing material for monitoring the purity of water.     

Synthesis and Crystal Structure of a New Diamine Complex CuC14（H2tn）

In an attempt to synthesize a new pyrimidine complex of copper(H) in a solution reaction of CuBr2 with 2,2‘-bis(hexahydropydmidine) and hydro-chloric acid, we unexpectedly obtained a bright yellow chip-like crystal of CuCl4(H2tn) [H2tn=(H3NCH2CH2CH2NH3)^2 ]. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group Pnma, with cell parameters: a=0.7216(2)nm, b=1.8308(6)nm, c=0.7553(3)nm, V=0.9953(6)nm^3, Z=4, F(000)=564, Mr=281.49, Dc=1.879 g/cm^3. u(Mo Ka)=3.204 mm^-1, R1=0.0248, wR2=0.0575. The analysis of the crystal structure indicates that the complex has a three-dimensional network structure, which is formed by hydrogen bonds and electrostatic interaction.     

论弹性波绕射与动应力集中问题

本文综述了弹性波绕射与动应力集中问题的复变函数解法,给出了单连通问题、多连通问题及多裂纹问题的具体求解过程及算式.      

掺钇α-Ni(OH)_2的研究

采用均匀络合共沉淀法 ,首次合成出了掺杂钇基 α-Ni(OH) 2 .并采用 XRD,FTIR和 SEM分析技术 ,对其结构及形貌进行了研究 .电化学测试表明 ,所制得的掺杂钇基 α-Ni(OH) 2 与掺铝的 α-Ni(OH) 2 和球形 β-Ni(OH) 2 相比 ,敲实密度 1 .6g/cm2 ,电化学比容量 3 3 0 m A·h/g以上 ,活性物质利用率大于 95 % ,循环可逆性好等优点 .