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971.
Multicomponent Self‐Assembly with a Shape‐Persistent N‐Heterotriangulene Macrocycle on Au(111) 下载免费PDF全文
Kang Cui Dr. Florian Schlütter Dr. Oleksandr Ivasenko Dr. Milan Kivala Dr. Matthias G. Schwab Dr. Shern‐Long Lee Dr. Stijn F. L. Mertens Dr. Kazukuni Tahara Prof. Yoshito Tobe Prof. Klaus Müllen Dr. Kunal S. Mali Prof. Steven De Feyter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(4):1652-1659
Multicomponent network formation by using a shape‐persistent macrocycle ( MC6 ) at the interface between an organic liquid and Au(111) surface is demonstrated. MC6 serves as a versatile building block that can be coadsorbed with a variety of organic molecules based on different types of noncovalent interactions at the liquid–solid interface. Scanning tunneling microscopy (STM) reveals the formation of crystalline bicomponent networks upon codeposition of MC6 with aromatic molecules, such as fullerene (C60) and coronene. Tetracyanoquinodimethane, on the other hand, was found to induce disorder into the MC6 networks by adsorbing on the rim of the macrocycle. Immobilization of MC6 itself was studied in two different noncovalently assembled host networks. MC6 assumed a rather passive role as a guest and simply occupied the host cavities in one network, whereas it induced a structural transition in the other. Finally, the central cavity of MC6 was used to capture C60 in a complex three‐component system. Precise immobilization of organic molecules at discrete locations within multicomponent networks, as demonstrated here, constitutes an important step towards bottom‐up fabrication of functional surface‐based nanostructures. 相似文献
972.
Liping Zhang Fan Guo Xinzheng Liu Jianhua Cui Yitai Qian 《Journal of Crystal Growth》2005,280(3-4):575-580
An alcohol-thermal route has been developed to the growth of single crystals of yellow metastable PbO in largest dimensions of 11×1×0.1 mm3, using freshly synthesized β-PbO crystallites as seeds. The transformation of metastable β-PbO to stable form (-PbO) can be slowed down by choosing appropriate solvent as the growth medium. The obtained β-PbO crystals have a strong orientational growth parallel to the (0 0 1) plane and exhibit a lath shape. Studies found that cooling rate and NaOH concentration also have great influence on the crystallographic forms of the final products during the alcohol-thermal process. 相似文献
973.
Bioactive glass-chitosan-alginate hybrid scaffolds were fabricated using BG sol as a dual function additive, which behaves as both bioactive inorganic phase to confer the bioactivity and cross-linker to improve the structural stability and mechanical properties. 相似文献
974.
The single-chain elasticity of a completely unfolded protein ((I27)8,modules of human cardiac titin) is studied in different liquid environments by the atomic force microscopy (AFM)-based single molecule force spectroscopy (SMFS).The experimental results show that there is a clear deviation between the force curves obtained in the aqueous and nonaqueous environments.Such a deviation can be attributed to the additional energy consumed by the rearrangement of the bound water molecules around the chain of the completely unfolded (I27)8 chain upon stretching in aqueous solution,which is very similar to the partial dehydration process from a denatured/unfolded to a native/folded protein.Through the analysis of the free energy changes involved in protein folding,we conclude that it is due to the weak disturbance of water molecules and the special backbone structures of proteins that the self-assembly of proteins can be achieved in physiological conditions.We speculate that water is likely to be an important criterion for the selection of self-assembling macromolecules in the prebiotic chemical evolution. 相似文献
975.
Zhijie Liu Dehui Xu Chunxi Zhou Qingjie Cui Tongtong He Zeyu Chen Dingxin Liu Hailan Chen Michael G. Kong 《Plasma Chemistry and Plasma Processing》2018,38(5):953-968
In this paper, we report the effects of the pulse polarity on the plasma jet’s discharge characteristics, particularly, on the production of the reactive oxygen and nitrogen species (RONS) and the inactivation efficiency of myeloma cells, for the purpose of identifying and elucidating the correlation between the dose of RONS and cell viability. Experimental results reveal that the positive plasma jet has a longer length than that for negative plasma jet with the equivalent pulse power. The positive pulse plasma jet would produce higher production of the excited reactive species (OH(A), N2(C), N2+(B), He(3s3S), O(3p5P)), the positive ions (N+, O+, N2+, O2+), and the aqueous species O2?, OH, and ONOO?, while negative plasma jet would generate higher concentration of the negative ions (OH?, O2?, NO2?, NO2?) and the aqueous species NO2? and NO3?. Additionally, the myeloma cells treated by positive plasma jet results in more cell apoptosis and more CD95 expression compared to negative plasma jet, indicating the impact for the cell apoptosis is more significant in the cellular response to the positive plasma jet. By comparing and analyzing the different doses of RONS to the responses of myeloma cells under positive and negative pulse plasma jet, our findings suggest the cell viability has a positive correlation with the concentration of the concentration of ONOO? and the concentration ratio of H2O2 to NO2?, implying the high concentrations for ONOO? and H2O2 might be responsible for the inactivation of myeloma cancer cells. 相似文献
976.
Facile preparation of ZrCO composite aerogel with high specific surface area and low thermal conductivity 总被引:2,自引:0,他引:2
Sheng Cui Hao Suo Feng Jing Shuwen Yu Jun Xue Xiaodong Shen Benlan Lin Shengjun Jiang Yu Liu 《Journal of Sol-Gel Science and Technology》2018,86(2):383-390
A novel ZrCO composite aerogel is synthesized using zirconium oxychloride and resorcinol–formaldehyde (RF) as precursors through the sol–gel route and carbothermal reduction process. The effects of different Zr/R molar ratios and calcination temperatures on the physical chemistry properties of ZrCO aerogels are investigated. The ZrCO composite aerogel consists of the C/ZrO2/ZrC ternary aerogel. The results show that with the increase of R/Zr molar ratios, the specific surface area and bulk density increase with calcination temperature up to 1300?°C, but decrease at even temperature (1500?°C). The specific surface area is as high as 637.4?m2/g for ZrCO composite aerogel (R:Zr?=?2:1), which was higher than ever reported. As the heat-treatment temperature increases to 1500?°C, the ZrC crystalline phase occurs and the t-ZrO2 phase still appears within the composite. The thermal conductivity of the carbon fiber mat-reinforced composite aerogel is as low as 0.057?W/m/K at room temperature (25?°C). 相似文献
977.
In situ template synthesis of SnO nanoparticles on nickel foam with high electrochemical performance
Yanhong Li Min Shi Meiri Wang Jing Li Yuanyuan Liu Hongtao Cui 《Journal of Sol-Gel Science and Technology》2018,86(2):423-430
A solution strategy performed at room temperature was presented for the in situ synthesis of SnO nanoparticles. SnO nanoparticles were prepared through the following sequent procedure: (1) preparation of rod-like Cd(OH)Cl utilizing the reaction between Cd2+ ions and epoxide; (2) production of Sn21Cl16(OH)14O6 template through the cation exchange reaction between Cd(OH)Cl and Sn2+ ions; (3) formation of SnO nanoparticles on nickel foam by the in situ reaction in strong alkaline electrolyte solution before electrochemical measurement. The as-prepared SnO had very small particle size and ordered nanostructure of particulate sheet, therefore resulting in its excellent electrochemical performance including high specific capacitance and high electrochemical stability for the charge-discharge cycle. Hence, the SnO nanoparticles synthesized in this work could be considered as one promising metal oxide for the utilization as electrode material in supercapacitor. 相似文献
978.
Pengbo Li Yiru Wang Shufang Zhang Liang Xu Gongchen Wang Jingnan Cui 《Tetrahedron letters》2018,59(14):1390-1393
A fluorescent probe HCAB based on twisted intramolecular charge transfer (TICT) mechanism has been designed and synthesized by introducing benzoyl moiety to 4-dimethylamino-2′-hydroxychalcone. HCAB showed excellent selectivity towards human serum albumin (HSA) among different proteins with a remarkable 160-fold fluorescence enhancement and a wider linear range 0–100?mg/L of HSA. Job’s Plot analysis suggested that the formation of HCAB-HSA complex followed a 1:1 stoichiometry. Molecular docking and the displacement assay demonstrated the binding site of HCAB was subdomain IIA and IB of HSA. We also tested HSA levels in human plasma for practical application, the results obtained from HCAB method were similar to those obtained from the standard clinical method. 相似文献
979.
Xiao-Hui Li Li-He Lu Xu-Hong Li Yun-Biao Li Yuan-Chang Duan De-Huan Fu Shuang-Xi Mei Tao Cui Jing-Kun Wang Zhao-Yun Zhu 《Tetrahedron letters》2018,59(11):995-998
The extract of the aerial and underground parts of Phlomis likiangensis afforded two new iridoid derivatives, namely as phloloside H (1) and phloline (2), along with four known compounds (3–6), and compound 2 was a novel normonoterpene. Their structures were elucidated on the basis of spectroscopic studies and chemical methods. Six compounds were assayed for cytotoxic, antibacterial and antioxidative activities, but were either inactive or very weakly active. 相似文献
980.
Two naturally occurring rare 5-oxo β-triketones, AB5046A and AB5046B, were efficiently synthesized in five linear steps with overall yields of 36% and 28%, respectively. The synthetic strategy highlighted the readily preparation of the key intermediate, 3-ethoxy-5-hydroxycyclohex-2-enone, from commercially available phloroglucinol. 相似文献