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TPMS (triply periodic minimal surface) sheet structure consists of a spatially continuous surface, which forms a periodic porous structure, and has outstanding mechanical performance and ultralight...

BiOBr nanosheets and BiOBr flower-like microspheres were prepared by hydrothermal method and solvothermal method, respectively. On this basis, BiOBr nanosheets were modified by reducing agent reduction, preparing successfully Bi/BiOBr nanosheets. The XRD, SEM, UV-VisDRS, XPS and UV-vis spectrophotometry were used to characterize the morphological structures, physical properties and surface element composition of the photocatalysts. In addition, photocatalytic activity was analyzed by the ability to degrade the antibiotic norfloxacin. The results indicated that after irradiation of 500 W xenon lamp for 180 min, the degradation rates for norfloxacin of BiOBr nanosheets, BiOBr flower like microspheres, and Bi/BiOBr photocatalyst were 34.7%, 72.1%, and 97.2%, respectively. And the degradation of norfloxacin was in accordance with the first order kinetic model. Compared with BiOBr nanosheets, the other two samples have better visible light photocatalytic activity, of which the photocatalytic activity of Bi/BiOBr was the highest. And the half-life of norbofloxacin degraded by Bi/BiOBr was shortened to 25 min. In addition, The results of capture experiments indicated that the main active groups involved in the degradation reaction of norfloxacin by Bi/BiOBr photocatalysts under visible light conditions were

Clay reduces fluidity and increases fluidity loss of concrete added with polycarboxylate superplasticiser. Sometimes it cuts down concrete durability. Fluidity of clay–cement paste with the addition of polycarboxylate superplasticiser, adsorption amount of polycarboxylate superplasticiser and ζ-potential has been tested to understand the effect of polycarboxylate superplasticiser on cement–clay systems. The results show that cement particles have a smooth surface; there are lots of layered or sheet structure existing on the surface of clay; when the particle size distribution is little different, the specific surface area of clay is 17 times that of cement; it is the reason why polycarboxylate superplasticiser adsorption on clay is much greater than that of cement. Initial adsorption amount and equilibrium adsorption amount of polycarboxylate superplasticiser on clay are 3–4 times that of cement; strong PC adsorption of clay is the main reason why the presence of clay reduces fluidity and increase...

In this paper, tubular structure has been obtained by self-assembly of cholesterol derivative via sol–gel process. The tube structure and the formation mechanism have been studied and certified by scanning electron microscopy, infrared, ultraviolet-visible spectroscopy (UV–vis) and x-ray diffraction (XRD) data. It is predicated that the tube has been formed by the curl of sheet structure, and the aggregates are composed of two molecules of 1 with H aggregate in laminar structure at micro level.

Three new complexes with embellished dicarboxylate, [ (2,2′-bpy)2(H2O)2] (1), [ (2,2′-bpy)2(H2O)2] (2), and [NiIIL(4,4′-bpy)(H2O)] (3) (H2L = 4,6-dibenzoylisophthalic acid, 2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra and X-ray diffraction. Complexes 1 and 2 are binuclear structures with 16-membered rings. Complex 3 shows a 2-D sheet structure. Intermolecular O–H ··· O interactions extend 1 and 2 into 1-D chains. Luminescence properties have been investigated for 1 and 2.

A new 2D cadmium(II) thiocyanato complex, [CdL(NCS)2]n (L = 2-acetylpyridine), has been prepared and characterized by IR spectra and single crystal X-ray diffraction. The Cd atom in the complex is coordinated by one N and one acetyl O atoms of 2-acetylpyridine, and two N atoms and two S atoms from four different end-to-end (μ1,3-) bridging thiocyanate groups. The thiocyanate groups link the [CdL] units to form a 2D sheet structure. The complex shows strong cytotoxic property to carcinoma cells.

Protein amyloid fibers are often found to have a beta-pleated sheet structure regardless of their sequence, leading some to believe that it is the molecule's misfolding that leads to aggregation. In this article, an alternative model is introduced for the amyloid community to consider, that fiber formation is a surface-energy minimization process, starting with the generation of colloidal particles and their linear assembly, and ending with structural evolution of the aggregates into mature fibers. We propose that aggregation drives conformational change and that a conformational change is not essential to initiate the aggregation process.

A summary report on the magnetic properties of some neptunyl(+1) complexes (two formates; (NH4)[NpO2(O2CH)2](1), [NpO2(O2CH)(H2O)](2), and a phthalate, [(NpO2)2(O2C)2C6H4(H2O)3] (3)) is presented based on the magnetic and 237Np Mossbauer data obtained in our group for powder samples and the available single-crystal structural data. It is demonstrated that the remarkable correlations exist between the magnetic properties, the 237Np Mossbauer parameters and the structural features (dimensionality, neptunyl (O=Np=O) bonding network structure, etc.) among these uniquely low-dimensional neptunyl complexes. The magnetic data show that 1 with neptunyl (O=Np=O) 1D chain structure is paramagnetic (or only marginally ferromagnetic) down to 2 K, while 2 and 3 with similar 2D neptunyl sheet structure order ferromagnetically at Tc = 12 and 4.5 K, respectively. In addition, 3 having two kinds of Np sites exhibited a two-step magnetization behavior below Tc. Consistent with these magnetic data, 237Np Mussbauer spectra o...

Amyloid fibrils were isolated from heterozygous Met 30 familial amyloidotic polyneuropathy (FAP) patients. A chelating agent, collagenase digestion and defatting agents were used to remove the serum amyloid P-component, collagen and other adherent tissue components from the fibrils. The characteristic birefringence of amyloid fibrils remained after purification. X-ray diffraction experiments were performed before and after the removal of adherent material. The predominant features from the X-ray diffraction pattern, consisting of a series of concentric rings, indicate the presence of a lipid structure in all the samples that had not been previously delipidated. In contrast, defatted fibrils exhibited only two reflections in the 4-30 A region: a sharp reflection corresponding to a 4.76 A spacing and a broad and diffuse one centered at 10.5 A spacing, both characteristic of a β-pleated sheet structure. The low angle pattern, from the purified material, shows one unique reflection at 63 A spacing.Analysis of...

The crystal and molecular structures of diethyl 6-[4-(4′-nitrophenylazo)phenoxy]hexylmalonate (1) as a comonomer in the synthesis of liquid-crystalline polymers and its 2′-nitrophenyl isomer (2) have been determined by X-ray analysis. Both compounds crystallize in space group P1 with two molecules per unit cell and the following lattice parameters. 1: a = 7.995(2), b = 10.699(2), c = 15.021(4) A, a = 95.04(2), β = 96.54(2), γ = 94.72(3)°. 2: a = 8.912(2), b = 9.664(2), c = 16.064(4) A, α = 98.68(2), β = 97.54(1), γ = 105.11(1)°. The structures were solved by direct methods and refined to R (wR) values of 0.082 (0.068) and 0.071 (0.076), respectively. The molecules have an optimum stretched shape excepted one of their two ethoxycarbonyl groups which is perpendicularly oriented to the molecular long axis. The molecular packing in the crystal can be described in terms of a sheet structure in which the sheets are penetrated by the laterally branched ethoxycarbonyl groups of neighboring sheets.