The expandable graphite (EG) modified TiO nanocomposites were prepared by the high shear method using the TiO nanoparticles (NPs) and EG as precursors, in which the amount of EG doped in TiO was 10 wt.%. Followed by the impregnation method, adjusting the pH of the solution to 10, and using the electrostatic adsorption to achieve spatial confinement, the Pt elements were mainly distributed on the exposed TiO, thus generating the Pt/10EG-TiO-10 catalyst.
View Article and Find Full Text PDFThis paper is based on the proximity engineering project of the Baishiyi tunnel group passing under the Chongqing West Station track group. Considering the train load and the spatial relationship of the tunnel and track groups, the settlement patterns, horizontal displacement, and differential settlement of the tunnel-strata-tracks system during the excavation process are studied through theoretical calculations and numerical simulation methods. The results indicate that the tunnel vault, strata, and track settlement deformation patterns are similar.
View Article and Find Full Text PDFTo solve the problem of freezing damage in cold-region tunnels, this study proposed a rubber airbag interlayered composite lining system, and tested its performance of buffering, pressure adjustment, waterproofing, and heat preservation by simulating a low-temperature environment in an artificial freezing chamber. The experiment results show that the frost-heaving force exerted on the lining can always be lower than 1.69 kPa by constantly adjusting the airbag pressure, and the maximum frost-heaving force can reach 28.
View Article and Find Full Text PDFAccurate estimation of concrete (including shotcrete) consumption plays a crucial role in tunnel construction. A novel method has been introduced to accurately estimate concrete consumption with terrestrial laser scanning (TLS). The estimation needs to capture TLS data of tunnel surfaces at different stages of construction.
View Article and Find Full Text PDFUnderstanding the adverse effects of tunnel crossing active faults on tunnel structures is crucial for ensuring their safe operation and construction. This paper presents the results of a series of model tests conducted at a scale of 1:40 using a fault sliding test box. Three sets of fault comparison tests were carried out, namely: (1) the tunnel does not cross the fault, (2) the spring stiffness is reduced, and (3) the model is not reinforced.
View Article and Find Full Text PDFAloperine is an alkaloid found in the seeds and leaves of the medicinal plant L. It has been used as herbal medicine in China for centuries due to its potent anti-inflammatory, antioxidant, antibacterial, and antiviral properties. Recently, aloperine has been widely investigated for its therapeutic activities.
View Article and Find Full Text PDFA reliable self-generating template strategy has been developed for the synthesis of flowerlike carbon nanosheets by hydrothermal carbonization in the presence of both silica and zinc acetate using glucose as the carbon source. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), Raman spectroscopy, nitrogen sorption isotherm measurement (BET) and element analysis revealed the morphology, crystal phase structure, porosity and chemical composition. The formation of the zinc silicate nanosheet template was due to the hydrolysis of amorphous silica and self-assembly under hydrothermal conditions.
View Article and Find Full Text PDFTunnel lining (bare-lining) cross-sections play an important role in analyzing deformations of tunnel linings. The goal of this paper is to develop an automatic method for extracting bare-lining cross-sections from terrestrial laser scanning (TLS) point clouds. First, the combination of a 2D projection strategy and angle criterion is used for tunnel boundary point detection, from which we estimate the two boundary lines in the X-Y plane.
View Article and Find Full Text PDFA highly porous metal-organic framework (Cu-TDPAT), constructed from a paddle-wheel type dinuclear copper cluster and 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine (H₆TDPAT), has been tested in Ullmann and Goldberg type C-N coupling reactions of a wide range of primary and secondary amines with halobenzenes, affording the corresponding N-arylation compounds in moderate to excellent yields. The Cu-TDPAT catalyst could be easily separated from the reaction mixtures by simple filtration, and could be reused at least five times without any significant degradation in catalytic activity.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
December 2011
In the crystal structure of the title coordination polymer, {[Zn(2)(C(24)H(18)N(4)O(10))(H(2)O)(4)]·H(2)O}(n), the mol-ecular building block (MBB), viz [Zn(2)(CO(2))(4)(H(2)O)(4)], comprises two Zn(II) cations, each bridged by three carboxyl-ate groups from different ligand mol-ecules. These two Zn(II) cations exhibit different coordination environments: a distorted trigonal-pyramidal coordination, as an inter-mediate, is formed by the two coordinated water mol-ecules and three carboxyl-ate groups, and a distorted octa-hedral geometry defined by three water mol-ecules and three carboxyl-ate groups, in which two carboxyl-ate groups from the same side of the clip glycoluril ring and one water mol-ecule are bidentate bridging, whereas others are monodentate units. Every ligand mol-ecule connects four MBBs, thus forming a three-dimensional structure.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
October 2011
In the crystal structure of the title coordination polymer, {[Zn(2)(C(17)H(8)O(10))(C(3)H(7)NO)(2)]·C(3)H(7)NO}(n), the mol-ecular build-ing block (MBB), viz. {Zn(2)(CO(2))(4)(C(3)H(7)NO)(2)}, comprises two zinc atoms, each bridged by three carboxyl-ate groups. These two Zn atoms exhibit different coordination environments: a distorted coordination intermediate between trigonal-pyramidal, and square-pyramidal formed by the two coordinated dimethyl-formamide mol-ecules and three carboxylate groups, and a distorted tetra-hedral coordination defined by carboxy-late groups of which three are bidentate bridging and the fourth is a monodentate ligand.
View Article and Find Full Text PDFSolvothermal reaction of a partially flexible ligand, H(4)L, and Cu(NO(3))(2)·2.5H(2)O afforded two cross-linked Kagomé lattices of formula [Cu(2)(L)](n): an acs net sustained by novel trigonal prismatic supermolecular building blocks (SBBs) and the first example of a partially pillared Kagomé net.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
June 2010
In the title coordination polymer, [Zn(C(8)H(4)O(4))(C(5)H(5)N)(2)](n), the Zn(II) atom, located on a twofold rotation axis, is tetra-coordinated by two monodentate O atoms from two different carboxyl-ate groups and two pyridyl N atoms, forming a distorted tetra-hedral geometry. The Zn(II) atoms are bridged by terephthalate ligands, generating an infinite zigzag chain along [101].
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2007
The interaction of a cationic water-soluble porphyrin, 5,10,15,20-tetrakis [4-(3-pyridiniumpropoxy)phenyl]porphyrin tetrakisbromide (TPPOC3Py), with anionic surfactant, sodium dodecyl sulfate (SDS), in aqueous solution has been studied by means of UV-vis, (1)H NMR, fluorescence, circular dichroism (CD) spectra and dynamic laser light scattering (DLLS), and it reveals that TPPOC3Py forms porphyrin-surfactant complexes (aggregates), including ordered structures J- and H-aggregates, induced by association with surfactant monomers below the SDS critical micelle concentration (cmc), and forms micellized monomer upon the cmc, respectively. The position of TPPOC3Py in the micelle is determined, which is not in the micelle core instead of intercalated among the SDS chains, most likely with the pyridinium group extending into the polar headgroup region of the micelle.
View Article and Find Full Text PDFThe interaction of a cationic water-soluble porphyrin, 5,10,15,20-tetrakis[4-(3-pyridiniumpropoxy)phenyl]prophyrin tetrakisbromide (TPPOC3Py), with beta-CD and HP-beta-CD in aqueous solution has been studied by UV-vis, 1H NMR, 2D-NOESY and MALDI-TOF MS, and it reveals that a stable 1:1 inclusion complex between TPPOC3Py and HP-beta-CD or beta-CD has formed, in which one of the meso substituents of porphyrin ring has deeply penetrated through the cavity of HP-beta-CD from secondary face. The inclusion constants of the complexes of TPPOC3Py-beta-CD and TPPOC3Py-HP-beta-CD are (1.6+/-0.
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