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991.
Zhongzheng Zhang Hui Wang Xinqing Chen Rongyong Xie Peng Gao Wei Wei Yuhan Sun 《Adsorption》2014,20(7):883-888
The sorption isotherms of CO2 in wet ordered mesoporous silica KIT-6 with different amounts of pre-adsorbed water were firstly collected experimentally using a volumetric method in the temperature range of 275–281 K. The isotherms show an inflection point indicating CO2 hydrates form in the pore spaces which is proofed by the enthalpy change calculated at the inflection pressure, and the quantity of water content shows considerable effect on the sorption capacity of CO2. The highest enhancement of sorption capacity in the presence of water is observed in wet KIT-6 sample with water loadings of 2.48, which is about 12.80 mmol/g and 1.86 times than that on dry sample. However, the saturation capacity is still far less than that what can be stored merely in the form of hydrates due to the low ratio of water utilization because of the large pore and the polar surface of KIT-6. 相似文献
992.
Hui Zhang Kan Zhan Yulu Chen Guoxia Chen Xiaomei Zhou Junxiu Liu Min Wu Henmei Ni 《Journal of Sol-Gel Science and Technology》2014,71(3):597-605
Three dimensional Liesegang spherical layers of CaHPO4 in gelatin ball were performed by employing CaCl2 and Na2HPO4 as the inner and outer electrolyte, respectively. Effects of concentrations of inner and outer electrolyte as well as pH on the morphologies of Liesegang rings (LRs) were investigated. As a result, it was observed that the time law, spacing law and width law found in 1D/2D gel systems were obeyed in this 3D gelatin system. The interaction of Ca2+ and HPO4 2? with gelatin matrix played a key role to the formation of LRs due to the existence of carboxylic groups on the gelatin chains. Using Ca2+ as the inner electrolyte, LRs were prepared. However, employing HPO4 2? as inner electrolyte, LRs were not obtained. Moreover, pH of gelatin solution greatly impacted on the formation of LRs. The number of LRs increased with the decrease of pH, whereas the width inversely decreased. pH 4.40 was a turn point, from which the spacing coefficient abruptly increased as pH increased. All these results indicated that the network was created by the interaction of Ca2+ and –COO? of gelatin chains, which dominated the formation of CaHPO4 LRs in gelatin. 相似文献
993.
M. Penchal Reddy W. Madhuri K. Sadhana I. G. Kim K. N. Hui K. S. Hui K. V. Siva Kumar R. Ramakrishna Reddy 《Journal of Sol-Gel Science and Technology》2014,70(3):400-404
Magnetic nickel ferrite (NiFe2O4) was prepared by sol–gel process and calcined in the 2.45 GHz singlemode microwave furnace to synthesize nickel nanopowder. The sol–gel method was used for the processing of the NiFe2O4 powder because of its potential for making fine, pure and homogeneous powders. Sol–gel is a chemical method that has the possibility of synthesizing a reproducible material. Microwave energy is used for the calcining of this powder and the sintering of the NiFe2O4 samples. Its use for calcination has the advantage of reducing the total processing time and the soak temperature. In addition to the above combination of sol–gel and microwave processing yields to nanoscale particles and a more uniform distribution of their sizes. X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and vibrating sample magnetometer were carried out to investigate structural, elemental, morphological and magnetic aspects of NiFe2O4. The results showed that the mean size and the saturation magnetization of the NiFe2O4 nanoparticles are about 30 nm and 55.27 emu/g, respectively. This method could be used as an alternative to other chemical methods in order to obtain NiFe2O4 nanoparticles. 相似文献
994.
基于二聚氰胺和三聚氰胺在Pt盘电极上对Ru(bpy)2+3的发光有增敏效果,建立了毛细管电泳电化学发光法同时分离检测乳制品中二聚氰胺和三聚氰胺的含量的新方法。进行实验条件优化,采用5 mmol/L Ru(bpy)32++60 mmol/L pH 8.5磷酸缓冲液,10 kV×10 s电动进样,光电倍增管高压为900 V,检测电位为1.18V,分离电压为12 kV,使得二聚氰胺和三聚氰胺得到了很好的分离检测,对奶粉样品进行添加回收率实验,二聚氰胺和三聚氰胺的回收率分别为94.6%~97.8%和95.9%~97.4%,相对标准偏差分别为3.2%~4.6%和2.7%~4.1%。 相似文献
995.
Yanli Li Peiran Zhao Dr. Teng Gong Han Wang Dr. Xingwu Jiang Hui Cheng Dr. Yanyan Liu Dr. Yelin Wu Prof. Wenbo Bu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22726-22732
Redox homeostasis is one of the main reasons for reactive oxygen species (ROS) tolerance in hypoxic tumors, limiting ROS-mediated tumor therapy. Proposed herein is a redox dyshomeostasis (RDH) strategy based on a nanoplatform, FeCysPW@ZIF-82@CAT Dz, to disrupt redox homeostasis, and its application to improve ROS-mediated hypoxic tumor therapy. Once endocytosed by tumor cells, the catalase DNAzyme (CAT Dz) loaded zeolitic imidazole framework-82 (ZIF-82@CAT Dz) shell can be degraded into Zn2+ as cofactors for CAT Dz mediated CAT silencing and electrophilic ligands for glutathione (GSH) depletion under hypoxia, both of which lead to intracellular RDH and H2O2 accumulation. These “disordered” cells show reduced resistance to ROS and are effectively killed by ferrous cysteine-phosphotungstate (FeCysPW) induced chemodynamic therapy (CDT). In vitro and in vivo data demonstrate that the pH/hypoxia/H2O2 triple stimuli responsive nanocomposite can efficiently kill hypoxic tumors. Overall, the RDH strategy provides a new way of thinking about ROS-mediated treatment of hypoxic tumors. 相似文献
996.
Songhao Guo Yongsheng Zhao Kejun Bu Yongping Fu Hui Luo Mengting Chen Matthew P. Hautzinger Yingqi Wang Prof. Song Jin Prof. Wenge Yang Prof. Xujie Lü 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17686-17692
A remarkable PL enhancement by 12 fold is achieved using pressure to modulate the structure of a recently developed 2D perovskite (HA)2(GA)Pb2I7 (HA=n-hexylammonium, GA=guanidinium). This structure features a previously unattainable, extremely large cage. In situ structural, spectroscopic, and theoretical analyses reveal that lattice compression under a mild pressure within 1.6 GPa considerably suppresses the carrier trapping, leading to significantly enhanced emission. Further pressurization induces a non-luminescent amorphous yellow phase, which is retained and exhibits a continuously increasing band gap during decompression. When the pressure is released to 1.5 GPa, emission can be triggered by above-band gap laser irradiation, accompanied by a color change from yellow to orange. The obtained orange phase could be retained at ambient conditions and exhibits two-fold higher PL emission compared with the pristine (HA)2(GA)Pb2I7. 相似文献
997.
Rational Design of Cyclometalated Iridium(III) Complexes for Three-Photon Phosphorescence Bioimaging
Dr. Chengzhi Jin Fengyin Liang Dr. Jinquan Wang Dr. Lili Wang Dr. Jiangping Liu Xinxing Liao Dr. Thomas W. Rees Bo Yuan Prof. Dr. Hui Wang Prof. Dr. Yong Shen Prof. Dr. Zhong Pei Prof. Dr. Liangnian Ji Prof. Dr. Hui Chao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16121-16125
Compared to 2PE (two-photon excitation) microscopy, 3PE microscopy has superior spatial resolution, deeper tissue penetration, and less defocused interference. The design of suitable agents with a large Stokes shift, good three-photon absorption (3PA), subcellular targeting, and fluorescence lifetime imaging (FLIM) properties, is challenging. Now, two IrIII complexes (3PAIr1 and 3PAIr2) were developed as efficient three-photon phosphorescence (3PP) agents. Calculations reveal that the introduction of a new group to the molecular scaffold confers a quadruple promotion in three-photon transition probability. Confocal and lifetime imaging of mitochondria using IrIII complexes as 3PP agents is shown. The complexes exhibit low working concentration (50 nm ), fast uptake (5 min), and low threshold for three-photon excitation power (0.5 mW at 980 nm). The impressive tissue penetration depth (ca. 450 μm) allowed the 3D imaging and reconstruction of brain vasculature from a living specimen. 相似文献
998.
Dr. Hui Wang Dr. Changcheng Jing Dr. Adam Noble Prof. Dr. Varinder Kumar Aggarwal 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17005-17018
The stereospecific 1,2-migration of boronate complexes is one of the most representative reactions in boron chemistry. This process has been used extensively to develop powerful methods for asymmetric synthesis, with applications spanning from pharmaceuticals to natural products. Typically, 1,2-migration of boronate complexes is driven by displacement of an α-leaving group, oxidation of an α-boryl radical, or electrophilic activation of an alkenyl boronate complex. The aim of this article is to summarize the recent advances in the rapidly expanding field of electrophile-induced stereospecific 1,2-migration of groups from boron to sp2 and sp3 carbon centers. It will be shown that three different conceptual approaches can be utilized to enable the 1,2-migration of boronate complexes: stereospecific Zweifel-type reactions, catalytic conjunctive coupling reactions, and transition metal-free sp2–sp3 couplings. A discussion of the reaction scope, mechanistic insights, and synthetic applications of the work described is also presented. 相似文献
999.
Xiangyu Ma Yuyuan Bai Yongbo Song Qinzhen Li Ying Lv Hui Zhang Prof. Haizhu Yu Prof. Manzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17387-17391
Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size-evolution principles. Reported here is the largest known FCC-based (FCC=face centered cubic) silver nanocluster, [Ag100(SC6H33,4F2)48(PPh3)8]−: the first all-octahedral symmetric nesting Ag nanocluster with a four-layered Ag6@Ag38@Ag48S24@Ag8S24P8 structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC-based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC-based Russian nesting doll model constitutes a new platform for the study of the size-evolution principles of Ag NCs. 相似文献
1000.
Bingjie Zhao Huiqin Wang Dr. Chunmiao Han Peng Ma Zhe Li Peng Chang Prof. Hui Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19204-19209
Device simplification is of practical significance for organic light emitting diodes (OLEDs), and remains the great challenge for deep-red emitters. Herein, a deep-red thermally activated delayed fluorescence molecule ( p TPA-DPPZ ) is reported which features a T shaped structure containing two triphenylamine (TPA) donors, one either side of a planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional groups leads to limited but sufficient molecular packing for effective carrier transport. The neat p TPA-DPPZ film achieves an around 90-fold improved radiation rate constant of 107 s−1 and the nearly unitary reverse intersystem crossing (RISC) efficiency, as well as accelerated emission decays for quenching suppression. The high radiation and RISC result in a photoluminescence quantum yield of 87 %. The bilayer OLED based on the p TPA-DPPZ emissive layer achieved the record external quantum efficiencies of 12.3 % for maximum and 10.4 % at 1000 nits, accompanied by the deep-red electroluminescence with the excellent color purity. 相似文献