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971.
Cheng Xin Kong De-Sheng Wang Ze Feng Yuan-Yuan Li Wen-Juan 《Journal of Solid State Electrochemistry》2017,21(5):1467-1475
Journal of Solid State Electrochemistry - The TiO2/solution interfacial junction is of scientific and practical importance in the field of photoelectrochemical water splitting. Illumination of this... 相似文献
972.
应用密度泛函理论,在DZP基组水平上研究了(5,5)型锗纳米管催化的氧还原反应(ORR)的性能以及可能的催化机理.计算结果表明,ORR在锗纳米管上可能经历O2解离、OOH解离、H2O2解离三种可能机理.无论是对哪种机理,整个ORR均遵循四电子反应路径.评估ORR性能的重要中间产物O和OH的吸附能分别为-4.33 eV和-2.21 eV,这与它们在贵金属铂(Pt)上的吸附能非常接近.此外,在GeNT上,整个ORR过程中最后一步生成的H2O分子的吸附能仅仅为-0.05 eV,比O2分子的吸附能弱得多,意味着整个ORR催化循环在GeNT上可以顺利更替.因此,联合ORR的反应能量数据和中间产物的吸附数据,可以认为(5,5)型锗纳米管具有类Pt的催化性能.溶剂效应计算结果表明,一些反应中间产物的吸附结构,如O中间体会在很大程度上受到溶剂效应的影响.对所研究的锗纳米管来说,溶剂效应可以促进其催化的ORR进程. 相似文献
973.
本文以气相色谱为主要手段,配合红外光谱、X—射线粉末衍射分析及电子顺磁共振技术,研究了十二钼磷酸及其盐在氢气中的还原热稳定性。从对上述化合物在氢气中热解过程的气相产物和各中间固相产物的分析可知,在实验的温度范围内(40~640℃),这些化合物的热分解过程通常分为三或四个阶段。实验发现,Keggin阴离子热解以及Mo~(6 )被还原的难易程度,取决于与Keggin阴离子结合的阳离子的种类。在同一实验条件下,如果阳离子本身难以还原,那么,Keggin阴离子的破坏以及Keggin阴离子中Mo~(6 )还原为金属相的过程,都将变得困难。 相似文献
974.
Licheng Wu Feilong Li Yutao Rao Bin Wen Ling Xu Mingbo Zhou Takayuki Tanaka Atsuhiro Osuka Jianxin Song 《Angewandte Chemie (International ed. in English)》2019,58(24):8124-8128
A reaction sequence of regioselective peripheral bromination, Suzuki–Miyaura coupling with 2‐borylated thiophene or pyrrole, and oxidative ring‐closure with FeCl3 allowed the synthesis of heterole‐fused earring porphyrins 4Pd and 9Pd from the parent earring porphyrin 1 . Differently pyrrole‐fused porphyrins 5H and 6H and their PdII complexes 5Pd and 6Pd were also synthesized. The structures of 4Pd , 5H, 6Pd , and 8Pd have been revealed by X‐ray analysis to be slightly twisted owing to constraints imposed by heterole‐fused structures. 5Pd exhibits an intensified band at 1505 nm, while 4Pd and 9Pd display small but remarkably red‐shifted absorption bands reaching around 2200 nm. 相似文献
975.
Wenfen Zhang Yongming Zhang Guangrui Zhang Xin Ba Shaige Xia Wuduo Zhao Dan Yin Shusheng Zhang 《Journal of separation science》2019,42(7):1374-1383
A new water‐soluble tetra‐proline‐modified calix[4]arene‐bonded silica stationary phase was prepared straightforwardly by an indirect method and characterized by elemental analysis, energy dispersive Spectrometry, solid‐state 13C NMR spectroscopy, Fourier‐transform infrared spectroscopy, and thermogravimetric analysis. Due to the simultaneous introduction of polar tetra‐proline and nonpolar calix[4]arene, the developed column possessing a double retention mode of reverse‐phase liquid chromatography and hydrophilic interaction liquid chromatography. A series of hydrophobic and hydrophilic test samples, including nucleosides and nucleotides, amines, monosubstituted benzenes, chiral compounds, and phenols, were used to evaluate the developed stationary phase. A rapid separation capability, high separation efficiency, and selectivity were achieved based on the multiple interactions between solutes and tetra‐proline‐modified calix[4]arene‐bonded silica stationary phase. Moreover, the developed stationary phase was further used to detect and separate hexamethylenetetramine in rice flour. All the results indicated the potential merits of the developed stationary phase for simultaneous separation of complex hydrophobic and hydrophilic samples with high selectivity. 相似文献
976.
Qiu‐Yan Wang Xin Dong Juan Yang Xiao‐Ting Zhen Li‐Hong Ye Chu Chu Bin Wang Yu‐Han Hu Hui Zheng Jun Cao 《Journal of separation science》2019,42(23):3579-3588
The quantification of three alkaloids is important because quantitative study is a means of assessing the reliability of the experimental method, and three alkaloids of peimine, peiminine, and peimisine are main active ingredients in Chinese Pharmacopoeia 2015. An effective method based on the matrix solid‐phase dispersion microextraction was developed for the extraction of alkaloid compounds in Fritillariae Thunbergii Bulbus. Target analytes were analyzed by capillary electrophoresis coupled with quadrupole time‐of‐flight mass spectrometry. The optimized experimental condition was that 50 mg Fritillariae Thunbergii Bulbus was blended homogeneously with 10 mg citric acid for 5 min. Two hundred microliters of water acidized by 1 mol/L hydrochloric acid (pH = 4.5) was selected to elute tested alkaloids. The results demonstrated that the investigated method had low limits of detection (1.32–1.59 ng/mL), good recoveries (86.63–98.12%), and reproducibility (relative standard deviations of peak areas < 0.87%). The proposed matrix solid‐phase dispersion microextraction coupled with capillary electrophoresis combined with quadrupole time‐of‐flight mass spectrometry was successfully applied for the extraction of alkaloids in plants. 相似文献
977.
Xin‐Shu Li Jun‐Dan An Jian‐Zhong Huo Tian‐Tian Wang Yong Li Yuan‐Yuan Liu Bin Ding 《无机化学与普通化学杂志》2019,645(23):1324-1333
In this work a 1,2,4‐triazole derivative 1‐(4‐aminobenzyl)‐1,2,4‐triazole (abtz) was utilized, one new cadmium(II) coordination polymer, namely [Cd(abtz)I2]n ( 1 ) was prepared through the powerful solvo‐thermal synthetic strategy. In compound 1 , the abtz building blocks are interlinked through the central CdII ions forming the two‐dimensional (2D) layer coordination framework. Powder X‐ray diffraction (PXRD) characterization also reveals that we have prepared the pure phases of coordination polymer 1 . Optical properties have been determined, which can behave the excellent photo‐luminescent emission of coordination polymer 1 . Photo‐luminescent experiment also reveals that coordination polymer 1 can behave the highly sensitive detection for acetone molecules with high Ksv value (Ksv = 4.12 ×104 L · mol–1) in the recyclable detection fashion. Additionally, coordination polymer 1 also can behave the highly sensitive detection for pollutant dichromate with excellent quenching efficiency Ksv (Ksv = 2.12 × 104 L · mol–1) and low detection limit [38 × 10–3 mM (S/N = 3)]. UV/Vis, photo‐luminescent lifetime, and PXRD patterns also have been determined to analyze the detection mechanism. 相似文献
978.
The ferrocene‐based polymer (PDPFDE) accompanied with traditional intumescent flame retardant (IFR) system (ammonium polyphosphate (APP)/pentaerythritol (PER) = 3/1, mass ratio) has been used as additive flame retardant in polypropylene (PP), aiming to lower the total loading amount. The thermal stability and fire retardant properties were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical combustion (UL‐94), and cone calorimetry (CONE). The fire retardant mechanism was studied by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The results showed that the PP1 with 25 wt% IFR only passed the UL‐94 V‐1 rating, but the PP6 loaded by 0.5 wt% PDPFDE and 22.5 wt% IFR possessed an LOI value of 28.5% and passed the UL‐94 V‐0 rating; the peak heat release rate (pHRR) and total heat release (THR) are decreased by 63% and 43%, respectively, compared with pure PP. In addition, the char residue of PP6 manifested a very compact and smooth surface, indicating a more effective barrier layer. Meanwhile, it was interesting that the addition of PDPFDE evidently improved the impact strength and elongation at break of PP/IFR composites. 相似文献
979.
980.
利用G-四链体DNA(5′-CTGGGAGGGAGGGAGGGA-3′)与氯化血红素结合形成G-四链体-Hemin DNA酶,其能高效催化H_2O_2氧化反应底物由无色变为绿色,当溶液中有Ag~+或Hg~(2+)存在时会阻碍该DNA酶的形成,导致绿色溶液变浅。基于此,建立了比色法测定Ag~+和Hg~(2+)的传感器。在最佳实验条件下,溶液的吸光度与Ag~+和Hg~(2+)浓度分别在100.0~1 000.0 nmol/L和80.0~800.0 nmol/L范围内具有良好的线性关系,检出限(3δ/Slope)分别为55.9 nmol/L和64.3 nmol/L。该方法具有较好的选择性,采用该方法对实际样品进行测试,结果满意。 相似文献