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991.
In this paper, based on the asymptotic property of the solution, we derive the corresponding convergence rates in terms of the frequency for the direct-Filon and linear continuous collocation methods, which solves an open problem in Brunner (2010) [1]. Numerical tests verify that the asymptotic orders obtained are optimal. 相似文献
992.
A novel fluorescent tweezer was designed and synthesised to sense hydrophobic amines in aqueous solution. Association of the guest was driven by both hydrophobic effect and electrostatic interactions, with the hydrophobic interactions being dominant. The affinity and selectivity of the sensor for amine-based stimulants are reported. 相似文献
993.
Xingxun Liu Hongxin Ma Long Yu Ling Chen Zhen Tong Pei Chen 《Journal of Thermal Analysis and Calorimetry》2014,115(1):659-665
Thermal oxidation degradation of high-amylose (80 %) cornstarch has been studied using thermogravimetry analyser coupled to Fourier transform infrared spectroscopy (TG-FTIR). The linear structure of amylose provides a modal material to understand how the starch microstructure affects on the decomposition mechanisms. Kinetics of the thermal oxidation has been studied using different methods. It is found that the thermal oxidation degradation is more complex than thermal degradation, thermal oxidation degradation kinetics of the starch can be interpreted in terms of multi-step degradation mechanism, the activation energies obtain from Flynn–Wall–Ozawa (F–W–O) method and modified Coats–Redfern method are in good agreement. TG-FTIR and FTIR results confirm that the thermal oxidation mechanism of starch is a process containing long chain scission and glowing combustion. 相似文献
994.
995.
Two water‐soluble 6‐(pyrazin‐2‐yl)‐1,3,5‐triazine‐2,4‐diamino (pzta)‐based Cu(II) complexes, namely [Cu(l ‐Val)(pzta)(H2O)]ClO4 ( 1 ) and [Cu(l ‐Thr)(pzta)(H2O)]ClO4 ( 2 ) (l ‐Val: l ‐valinate; l ‐Thr: l ‐threoninate), were synthesized and characterized using elemental analyses, molar conductance measurements, spectroscopic methods and single‐crystal X‐ray diffraction. The results indicated that the molecular structures of the complexes are five‐coordinated and show a distorted square‐pyramidal geometry, in which the central copper ions are coordinated to N,N atoms of pzta and N,O atoms of amino acids. The interactions of the complexes with DNA were investigated using electronic absorption, competitive fluorescence titration, circular dichroism and viscosity measurements. These studies confirmed that the complexes bind to DNA through a groove binding mode with certain affinities (Kb = 4.71 × 103 and 1.98 × 103 M?1 for 1 and 2 , respectively). The human serum albumin (HSA) binding properties of the complexes were also evaluated using fluorescence and synchronous fluorescence spectroscopies, indicating that the complexes could quench the intrinsic fluorescence of HSA in a static quenching process. The relevant thermodynamic parameters revealed the involvement of van der Waals forces and hydrogen bonds in the formation of complex–HSA systems. Finally, molecular docking technology was also used to further verify the interactions of the complexes with DNA/HSA. 相似文献
996.
Promoted by metallic cadmium which was produced by reduction of CdCl2 H2O with samarium in situ, allyl bromide and α-bromocarboxylates react with diorgano diselenides in aqueous solutions to give allylic-type selenides and α-selenocarboxylates in moderate to good yields. 相似文献
997.
针对三维调整机难以实现多台同步工作,设计了基于PLC的同步控制方案。在同步控制系统方案中,采用西门子PLC通过工业无线以太网进行同步控制,由各维度油缸的位移传感器来保证同步控制的精确性。经实验,证实了此系统的精度满足设计要求,实现了同步控制的效果。 相似文献
998.
999.
1000.
A one-pot synthesis of the trisubstituted imidazole derivatives from α-acetoxy-α-chloro-β-keto-esters, aldehydes, and ammonium acetate has been developed. 相似文献