Search results

SEM and EDAX analyses revealed formation of heterogeneous structure with well-distributed nanospheres and nanorods.
The diffraction patterns confirm the polycrystalline structure of the ZnO-TiO2 nanocomposites.
In contrast, the nanorod-like structures are predominantly composed of Ti and O.
Chebbi, "Synthesis and characterizations of zinc oxide nanoparticles and its ability to detect O2 and NH3 gases,"Results in Chemistry, 6 (2023) 101064
Wang, "Enhanced gas sensing properties by SnO2 nanosphere functionalized TiO2 nanobelts,"Journal of Materials Chemistry, 22 (2012) 3544-3548

.:2.5, flexural strength improved by 52.4%, 54.3%, 20.1% respectively, compressive strength increased by -1.5%, 6.5% and- 2.1%.And analyzed the mechanism of flexural and compressive from the chemistry of sisal fiber and cement. 1 Introduction In recent years, people requires building materials with better performance and green function.Cement mortar is one of commonly used building materials, but its low flexural strength, poor permeability, easy cracking and other defects to prevent its widely used[1].To solve the problem, people began to explore in ordinary cement mortar mixed with a certain amount of fiber to obtain fiber reinforced cement mortar with good flexural, splitting resistance, permeability and other properties.
In accordance with same mass ratio, under the condition of sisal fiber replaces sand , sisal fiber has a bigger volume and surface area ratio, and the cavity structure of sisal fiber itself makes its water absorbing ability of unit mass is better than sand.So sisal fiber dosage is 4.5 kg/m3, compared No.3 and No.1 ,found No.3 surface area increases, water absorbing mass become bigger, resulting in mobility of sisal fiber cement mortar decrease by 11.1%.At the same time, sisal fiber reduces the surface drainage, sisal fiber meshing in mortar distribution also effectively prevent liquidity, effectively improving the workability of sisal fiber cement mortar. 2.2 determination of flexural strength test Under the condition of relevant test procedures, Block are maintenanced to 3 d, 7 d and 28 d for flexural strength test, flexural strength test results are shown in table 3 below.
degrees are different.Compared No.2 to No.5, and found the compressive strength of No.3 was little greater than No. 2.But it of No.3 and No.4 gradually reduce.No.3 namely which water cement ratio is 0.45 had minimum impact on compressive strength. 3d had a 6.5% lower, 7d had a 6.5% greater but 28d had a 18.9% lower than the benchmark.(2)compared with the benchmark, it of No.2 reduced by 7.1%, 4.6%, 5.7%respectively,it of No.4 reduced by 36.7%, 31.1%, 28.8%;it of No.5 reduced by 61.2%, 65.1% and 61.3% respectively in 3 ages.This shown that when the sisal fiber mortar dosage is for fixed value and water-binder ratio is greater than 0.45, compressive strength decreases with the increase of water cement ratio. 3 Mechanism analysis 3.1 bending mechanism analysis Internal defects are the main factors of cement base composite material damage [8].Short sisal fiber in cement mortar randomly distributed in three-dimensional space, reducing its internal defects, which changed the internal structure

., 51, 420066, Kazan, Russia aapogoreltsev@rambler.ru, bmatukhinvl@mail.ru, celena.gazeeva@list.ru, dev-shmidt@mail.ru, edima.shulgin@rambler.ru Keywords: nuclear quadrupole resonance NQR, the electric field gradient (EFG), quadrupole parameters, ab initio calculations of the electronic structure, electron density distribution.
Along with the plane structure the covellite has interesting electrical properties: electrical resistance is low (~ 10-7 Ohm × m), semiconductor zone gap 1.27-1.75 eV [1], and after the phase transition to the orthorhombic phase at 55 K becomes superconducting at 1.7 K.
Tsirelson, Quantum chemistry.

Figure 1 represents the crystal structure of magnesium indium oxide.
Fig. 1: Crystal structure of inverse magnesium indium oxide.
From XRD they confirmed the spinel structure.
West, “Solid State chemistry and its Application”, John Wiley, New York, 1998 [40] N.H.Yanagi, H.
Journal of Solid state Chemistry 154 (2000) 476-482 [52] Knodle, W., Research and Development, 28(8): (1986) 73 [53] Neugebauer, C.A., Handbook of Thin Films Technology, McGraw-Hill, Ch. 8,. 8-3 [54] Osgood, R.M., and Gilgen, H.

Microstructural properties such as pore structure and hydration play a decisive role in determining the properties of a concrete.
This paper presents the investigation on pore structure and hydration process of high strength concrete.
Permeability and other durability related properties of concrete are directly affected by the pore structure.
The determination of pore structure has, therefore, vital importance in the evaluation of performance of concrete.
Lea: The Chemistry of Cement and Concrete, Edward Arnold, London (1970) [5] J.

Ultrafine NiFe2O4 particles with spinel structure were prepared in the system of water-in-oil microemulsion of water/Triton X-100/n-hexanol/cyclohexane.
It not only reveals special physics and chemistry performance when a nano-materials entrusts with, but also has the special magnetism performance.
To further develop new preparation technique, herein, the ultrafine NiFe2O4 particles with spinel structure are prepared in the system of water-in-oil microemulsion of water/Triton X-100/n-hexanol/cyclohexane will be reported.
The second peak around 332.0℃ signifies a phase transition from amorphous phase to crystalline spinel, suggesting that the NiFe2O4 particles with spinel structure can be obtained around 300℃.

The results show that: hexagonal structured crystals can be prepared at the above-mentioned synthetic temperature; as to the sample obtained at 65˚C, its average grain size is about 20~50um and it has a petal-like surface.
The result indicates that all the ZnIn2S4 crystals prepared at the three different temperatures have hexagonal structure (PDF Card No.01-089-3962) with good crystallization and no impurity peak.
Conclusions ZnIn2S4 catalysts can be synthesized in one step at temperatures (45˚C~65˚C) slightly higher than room temperature, and the sample obtained at 65˚C (Figure 2c) has about 20~50um grain size with hexagonal structure and petal-like surface morphology.
Vol. 24(2008), P.7599 [10] Shaohua Shen, Liang Zhao, and Liejin Guo: Journal of Physics and Chemistry of Solids.

Study on the dispersion of nanometer TiO2 powder by Sol-Gel method Fang Zhao1,a,Yaqiong Zhao1, Yuanyuan Li1 ,Gang Ni1b 1College of Chemistry and Chemical Engineering, Ningxia University，Yinchuan 750021，PR China azfwalnut_521@163.com, bCorresponding author nigang@nxu.deu.cn Keywords: Nanometer TiO2, Surfactants, Sol-gel processes, Degradation pollutiontant.
The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM).
Common sol–gel methods employing direct addition of water molecules in a sol can lead to the immediate precipitation of amorphous particles with uncontrolled structure due to the rapid hydrolysis and condensation reactions between the highly reactive alkoxide titanium precursors and water[10-12].
The nanocrystalline anatase structure was confirmed by (101), (004) , (200) , (105) and (211) diffraction peaks[13].

The crystalline structure of the nanostructure was determined by transmission electron microscope.
It has been reported that Fe2O3 nanowires and nanobelts with rhombic hexahedral structure has been prepared using the method of thermal oxidation.
Crystalline structure of nanosheets can be calibrated by the electron diffraction pattern with the ASTM card which can acquire crystal indices.
Chinese Journal of Inorganic Chemistry, 2000, 16(2):213-217

To describe the anion and cation distributions of NaCl solution in vicinity of graphene nanopores, a new MD model was developed by considering thermal vibration of wall atoms, the structure of solvent molecules and ion sizes.
We found that Na+ and Cl- ions accumulated near the surface of graphene membrane and behaved the layering structure.
Furthermore, Na+ and Cl- ions accumulated near the surface of graphene membrane and behaved the layering structure, leading to the positions of transmembrane potential drop unchanged with pore diameter.
Berendsen: Journal of Computational Chemistry. vol. 26 (2005), p. 1701-1718 [9] B.