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61.
62.
Using the tricyano precursor (Bu(4)N)[(Tp)Cr(CN)(3)] (Bu(4)N(+) = tetrabutylammonium cation; Tp = tris(pyrazolyl)hydroborate), a pentanuclear heterometallic cluster [(Tp)(2)Cr(2)(CN)(6)Cu(3)(Me(3)tacn)(3)][(Tp)Cr(CN)(3)](ClO(4))(3)·5H(2)O (1, Me(3)tacn = N,N',N'-trimethyl-1,4,7-triazacyclononane), three tetranuclear heterometallic clusters [(Tp)(2)Cr(2)(CN)(6)Cu(2)(L(OEt))(2)]·2.5CH(3)CN (2, L(OEt) = [(Cp)Co(P(O)(OEt)(2))(3)], Cp = cyclopentadiene), [(Tp)(2)Cr(2)(CN)(6)Mn(2)(L(OEt))(2)]·4H(2)O (3), and [(Tp)(2)Cr(2)(CN)(6)Mn(2)(phen)(4)](ClO(4))(2) (4, phen = phenanthroline), and a one-dimensional (1D) chain polymer [(Tp)(2)Cr(2)(CN)(6)Mn(bpy)](n) (5, bpy = 2,2'-bipyridine) have been synthesized and structurally characterized. Complex 1 shows a trigonal bipyramidal geometry in which [(Tp)Cr(CN)(3)](-) units occupy the apical positions and are linked through cyanide to [Cu(Me(3)tacn)](2+) units situated in the equatorial plane. Complexes 2-4 show similar square structures, where Cr(III) and M(II) (M = Cu(II) or Mn(II)) ions are alternatively located on the rectangle corners. Complex 5 consists of a 4,2-ribbon-like bimetallic chain. Ferromagnetic interactions between Cr(III) and Cu(II) ions bridged by cyanides are observed in complexes 1 and 2. Antiferromagnetic interactions are presented between Cr(III) and Mn(II) ions bridged by cyanides in complexes 3-5. Complex 5 shows metamagnetic behavior with a critical field of about 22.5 kOe at 1.8 K. 相似文献
63.
Longdong Liu Ruzhong Zuo Qian Sun Qi Liang 《Journal of Sol-Gel Science and Technology》2013,65(3):384-387
The 0.2Bi(Zn1/2Ti1/2)O3–0.8PbTiO3 (0.2BZT–0.8PT) ferroelectric thin film was successfully fabricated on Pt(111)/Ti/SiO2/Si substrates by a sol–gel method. The result indicates that the film exhibits the (100) preferred orientation and has a relatively dense and uniform microstructure with a thickness of ~230 nm. The formation mechanism of the oriented films was ascribed to the growth of the (100) oriented PbO layer at ~450 °C during a layer-by-layer crystallization process. Temperature-dependent electrical properties of the 0.2BZT–0.8PT films were investigated, showing that the film has a potential for high temperature applications. 相似文献
64.
Xiaohua Zhu Qifang Jiao Chuyi Zhang Xiaoxi Zuo Xin Xiao Yong Liang Junmin Nan 《Mikrochimica acta》2013,180(5-6):477-483
We have developed a stable and sensitive nonenzymatic glucose sensor by modifying a glassy carbon electrode (GCE) with a composite incorporating nickel(II) oxides and reduced graphene. The oxides were generated by directly electrodepositing nickel on the GCE with a graphene modifier using a multi-potential pulse process, and then oxidizing nickel to nickel(II) oxides by potential cycling. In comparison to the conventional nickel(II) oxides-modified GCE, this new nickel(II) oxides-graphene modified GCE (NiO-GR/GCE) has an about 1.5 times larger current response toward the nonenzymatic oxidation of glucose in alkaline media. The response to glucose is linear in the 20 μM to 4.5 mM concentration range. The limit of detection is 5 μM (at a S/N of 3), and the response time is very short (<3 s). Other beneficial features include selectivity, reproducibility and stability. A comparison was performed on the determination of glucose in commercial red wines by high-performance liquid chromatography (HPLC) and revealed the promising aspects of this sensor with respect to the determination of glucose in real samples. Figure
A stable and sensitive nonenzymatic glucose sensor is developed by preparing the nickel(II) oxides-reduced graphene nanocomposite modified glassy carbon electrode (NiO-GR/GCE), and then used to detect the glucose contents in the commercial red wines. This NiO-GR/GCE also has a high selectivity 相似文献
65.
Using the ns pulse radolysis, we studied the characteristic absorption spectrum and kinetic decay of cytosine anion radical (Cyt-). Results showed that the characteristic absorption of Cyt- was located at λ=355±5 nm, and decayed following the first order kinetics with τ1/2=265 ns at pH=7.0. The decay became slower and τ1/2 rapidly rised with the increment of pH value, Cyt- protonated at C6 in acidic solution, and the characteristic absorption was located at λ=310±5 nm, and decayed following the second order kinetics: Cyt- protonated at N3 in aqueous solution of pH≥7, and the characteristic absorption was located at λ=295±5 nm, and decayed following the second order kinetics. 相似文献
66.
In this contribution, surface-enhanced Raman spectroscopy (SERS) based on conical holed glass substrates deposited with silver colloids was reported for the first time. It combines the advantages of both dry SERS assays based on plane films deposited with silver colloids and wet SERS assays utilizing cuvettes or capillary tubes. Compared with plane glass substrates deposited with silver colloids, the conical holed glass substrates deposited with silver colloids exhibited five-to ten-folds of increase in the rate of signal enhancement, due to the internal multiple reflections of both the excitation laser beam and the Raman scattering photons within conical holes. The application of conical holed glass substrates could also yield significantly stronger and more reproducible SERS signals than SERS assays utilizing capillary tubes to sample the mixture of silver colloids and the solution of the analyte of interest. The conical holed glass substrates in combination with the multiplicative effects model for surface-enhanced Raman spectroscopy (MEMSERS) achieved quite sensitive and precise quantification of 6-mercaptopurine in complex plasma samples with an average relative prediction error of about 4% and a limit of detection of about 0.02 μM using a portable i-Raman 785H spectrometer. It is reasonable to expect that SERS technique based on conical holed enhancing substrates in combination with MEMSERS model can be developed and extended to other application areas such as drug detection, environmental monitoring, and clinic analysis, etc. 相似文献
67.
A simple and reliable RP-HPLC method has been developed for the simultaneous determination of ropivacaine and antipyrine in perfusate samples. Samples were analyzed on an ODS column with UV detection at 210 nm after liquid-liquid extraction. The mobile phase consisted of potassium dihydrogenphosphate (25 mM, adjusted to pH 5.0 with phosphoric acid)-acetonitrile (79:21, v/v). The method has been validated to be precise, accurate and linear. It has been applied to the investigation of placental transfer of ropivacaine via a dually perfused cotyledon model of human placenta in vitro. 相似文献
68.
Taihong Yan Chen Zuo Weifang Zheng Guoan Ye Xiaorong Wang 《Journal of Radioanalytical and Nuclear Chemistry》2009,280(3):585-588
The kinetics of the reductive stripping of plutonium(IV) by dihydroxyurea (DHU) in 30% TBP/kerosene-HNO3 system was studied with a constant interfacial area cell. The stripping rate of plutonium(IV) increases with the increase
of the stirring speed of two phases and the interfacial area. The activation energy of this process is 28.4 kJ/mol. Under
the given experimental conditions, the mass transfer of Pu is not controlled by redox reaction, but controlled by molecular
diffusion from the organic phase to organic film layer and from the aqueous film layer to aqueous phase. The rate equation
of reductive stripping (process is controlled by diffusion) was obtained as: r
0 = k′[Pu(IV)]0[DHU]a
0.16[HNO3]a
−0.34. The rate constant k′ is (5.0±0.4)·10−2 (mol/L)0.18·min−1 at 18.0°C. 相似文献
69.
One Step Preparation of Reduced Graphene Oxide/Pd–Fe3O4@Polypyrrole Composites and Their Application in Catalysis 下载免费PDF全文
Dr. Tongjie Yao Hao Wang Quan Zuo Dr. Jie Wu Dr. Xiao Zhang Dr. Fang Cui Dr. Tieyu Cui 《化学:亚洲杂志》2015,10(9):1940-1947
The simple preparation of catalysts with superior catalytic activity and good reusability is highly desirable. Herein, we report a novel strategy to construct reduced graphene oxide (rGO)/Pd–Fe3O4@polypyrrole (PPy) catalysts with Pd and Fe3O4 nanoparticles anchored on a rGO nanosheet surface and wrapped in a PPy shell. The synthesis and assembly of both the Pd and Fe3O4 nanoparticles, the preparation of the PPy layer, and the reduction of graphene oxide nanosheets were finished in one step. In the system, the PPy layer not only prevented aggregation of Pd and Fe3O4 nanoparticles, but also generated a synergistic effect with precursor Pd2+ ions, which led to a high dispersity of as‐prepared Pd nanoparticles. Although the procedure was simplified to one step, the catalytic activity and reusability were not sacrificed. In the reduction of 4‐nitrophenol, their catalytic performance was better than that in recent reports. Moreover, the catalysts showed good reusability owing to their magnetic properties. 相似文献
70.
Clean Synthesis of an Economical 3D Nanochain Network of PdCu Alloy with Enhanced Electrocatalytic Performance towards Ethanol Oxidation 下载免费PDF全文
Jiawei Liu Zhao Huang Kai Cai Huan Zhang Dr. Zhicheng Lu Tingting Li Yunpeng Zuo Prof. Heyou Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17779-17785
A one‐pot method for the fast synthesis of a 3D nanochain network (NNC) of PdCu alloy without any surfactants is described. The composition of the as‐prepared PdCu alloy catalysts can be precisely controlled by changing the precursor ratio of Pd to Cu. First, the Cu content changes the electronic structure of Pd in the 3D NNC of PdCu alloy. Second, the 3D network structure offers large open pores, high surface areas, and self‐supported properties. Third, the surfactant‐free strategy results in a relatively clean surface. These factors all contribute to better electrocatalytic activity and durability towards ethanol oxidation. Moreover, the use of copper in the alloy lowers the price of the catalyst by replacing the noble metal palladium with non‐noble metal copper. The composition‐optimized Pd80Cu20 alloy in the 3D NNC catalyst shows an increased electrochemically active surface area (80.95 m2 g?1) and a 3.62‐fold enhancement of mass activity (6.16 A mg?1) over a commercial Pd/C catalyst. 相似文献