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201.
Lanthanide nitrate complexes with the heptadentate ligand L (6-[2-(2-(diethylamino)-2-oxoethoxy)ethyl]-N,N,12-triethyl-11-oxo-3,9-dioxa-6,12-diazatetradecanamide), [Ln(2)L(NO(3))(6)] (Ln = La, Nd, Sm, Eu, Ho), have been prepared and characterized. The X-ray crystallographic studies show that, in [La(2)L(NO(3))(6)(H(2)O)].H(2)O (1), two complex cations [LaL(H(2)O)](3+) are linked by a hexanitrato anion [La(NO(3))(6)](3)(-) and form a trinuclear cation. In [Nd(2)L(NO(3))(6)(H(2)O)].CHCl(3).1/2CH(3)OH.1/2H(2)O (2), one complex cation [NdL(H(2)O)](3+) and a hexanitrato complex anion [Nd(NO(3))(6)](3)(-) are linked by a bridging NO(3)(-) to form a dinuclear complex. In both complexes, the bridging nitrate is an unusual tetradentate ligand. The metal ions are 12-coordinated in hexanitrato anions and 10-coordinated in complex cations. The chainlike supramolecular structures of La(3+) complex are parallel and have no hydrogen bonds in between, while, in the Nd(3+) complex, a chiral cavity is formed by hydrogen bonds between two adjacent supramolecular chains. These influences are further investigated by assessing the separation efficiency of L and (1)H NMR spectra of its lanthanide nitrate mixtures in solution. 相似文献
202.
Kam Yee Yoon Wen Siang Tan Beng Ti Tey Khai Wooi Lee Kok Lian Ho 《Electrophoresis》2013,34(2):244-253
Hepatitis B core antigen (HBcAg) expressed in Escherichia coli is able to self‐assemble into large and small capsids comprising 240 (triangulation number T = 4) and 180 (triangulation number T = 3) subunits, respectively. Conventionally, sucrose density gradient ultracentrifugation and SEC have been used to separate these capsids. However, good separation of the large and small particles with these methods is never achieved. In the present study, we employed a simple, fast, and cost‐effective method to separate the T = 3 and T = 4 HBcAg capsids by using native agarose gel electrophoresis followed by an electroelution method (NAGE‐EE). This is a direct, fast, and economic method for isolating the large and small HBcAg particles homogenously based on the hydrodynamic radius of the spherical particles. Dynamic light scattering analysis demonstrated that the T = 3 and T = 4 HBcAg capsids prepared using the NAGE‐EE method are monodisperse with polydispersity values of ~15% and ~13%, respectively. ELISA proved that the antigenicity of the capsids was not affected in the purification process. Overall, NAGE‐EE produced T = 3 and T = 4 capsids with a purity above 90%, and the recovery was 34% and 50%, respectively (total recovery of HBcAg is ~84%), and the operation time is 15 and 4 times lesser than that of the sucrose density gradient ultracentrifugation and SEC, respectively. 相似文献
203.
Jingyi Cai Haoshan Wei Prof. Yong Zhang Rui Cai Dr. Xueru Zhang Prof. Yan Wang Prof. Jiaqin Liu Prof. Hark Hoe Tan Prof. Ting Xie Prof. Yucheng Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(25):7300-7306
Efficient separation of photogenerated electron–hole pairs is a crucial factor for high-performance photocatalysts. Effective electron–hole separation and migration could be achieved by heterojunctions with suitable band structures. Herein, a porous SrTiO3/SrSO4 heterojunction is prepared by a sol-gel method at room temperature followed by an annealing process. XRD characterization suggests high crystallinity of the heterostructure. A well-defined interface between the two phases is confirmed by high-resolution (HR)TEM. The photocatalytic H2 evolution productivity of the SrTiO3/SrSO4 heterojunction with Pt as co-catalyst reaches 396.82 μmol g−1 h−1, which is 16 times higher than that of SrTiO3/Pt. The boosted photocatalytic activity of SrTiO3/SrSO4/Pt can be ascribed to the presence of SrSO4, which promotes the transfer and migration of photogenerated carriers by forming the heterojunction and porous structure, which provides a large amount of active sites. This novel porous heterostructure brings new ideas for the development of high-efficiency photocatalysts for H2 release. 相似文献
204.
H. M. Noor ul Huda Khan Asghar Yi Tan Shuang Shi Dachuan Jiang Shiqiang Qin Jiao Liao Shutao Wen Wei Dong Yao Liu 《Applied Physics A: Materials Science & Processing》2014,115(3):753-757
Small amounts of multicrystalline silicon were melted in an electron beam furnace in different experimental conditions in order to investigate the oxygen evaporation behavior during the electron beam melting (EBM) process. The oxygen content level before and after EBM was determined by secondary ion mass spectroscopy. The oxygen content was reduced from 6.177 to 1.629 ppmw when silicon was melted completely at 15 kW with removal efficiency up to 73.6 %. After that, it decreased continually to <0.0517 ppmw when the refining time exceeded 600 s with a removal efficiency of more than 99.08 %. During the melting process, the evaporation rate of silicon is 1.10 × 10?5 kg/s. The loss of silicon could be reduced up to 1.7 % during oxygen removal process to a desirable figure, indicating EBM is an effective method to remove oxygen from silicon and decrease the loss of silicon. 相似文献
205.
Fen Ran Huili Fan Lingren Wang Lei Zhao Yongtao Tan Xuanxuan Zhang Lingbin Kong Long Kang 《天然气化学杂志》2013,(6):928-934
A novel bird nest-like nanostructured MnO2(BNNS-MnO2) was prepared by a facile and cost-effective strategy. Their structures and morphologies were characterized by field emission scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction. Capacitive behaviors were investigated by cyclic voltammetry and galvanostatic charge-discharge. The obtained nano-MnO2 possesses a well designed loose-assembled hierarchical nanoarchitecture with an appropriate crystallinity which gives rise to excellent performances as an electrode material for supercapacitors. A maximum specific capacitance of 917 F/g has been obtained at a current density of 5 mA/cm2 in 6 mol/L KOH aqueous solution, and a specific capacitance of 210 F/g has been maintained for 500 cycles. As the low cost of MnSO4 and KCr2O7 and the low reaction temperature, the present method avoids the requirements for complicated operations, time/energy-consuming and expensive reagents, and perhaps is ready for the industrialization of nano-MnO2 production. 相似文献
206.
In this work, a new type of hydrophobic stationary phase that provide electrostatic interactions with analytes was developed by bonding β-phenylethylamine as a functional ligand to silica. This stationary phase can separate proteins with similar hydrophobicity that traditional hydrophobic resins cannot. Hen egg white was separated to examine the selectivity. The results show that the introduced electrostatic interactions are an important factor for the resolution enhancement and the new resin could have important applications in separation and purification of biological macromolecules. 相似文献
207.
Nonlinear Dynamics - This paper focuses on the finite-time synchronization problem for a kind of general complex networks with intrinsic time-varying delays and hybrid couplings (i.e., containing... 相似文献
208.
A reliable method for direct synthesis of β‐dichlorosubstituted acetanilides is reported. The key transformation involves the oxidative and catalytic cleavage of a carbon‐carbon bond in the presence of iodine trichloride (ICl3). In this protocol ICl3 is used not only as the catalyst but also as the oxidant which widely broadens the scope of its application in organic synthetic chemistry. 相似文献
209.
4-Hydroxybenzocyclobutene was prepared in good yield from the demethylation of 4-methoxybenzocyclobutene with aluminum iodide in acetonitrile. 相似文献
210.