Search results

Crystal structure of the materials was studied by powder X-ray diffraction (XRD) technique (Bruker D-8 employing nickel filtered CuKα radiation).
(1) For ideal cubic perovskite structure t=1 and closer the value of “t” is to unity, the greater is the stability of the perovskite structure.
Three crystal structures were observed so far in these types of materials, viz. cubic (Fm3m) [8], monoclinic (P21/n) [9], tetragonal (P4/mnc) [6].
X-ray diffraction studies have shown that the combustion products are single phase and have complex cubic perovskite structures.
Wells, Structural Inorganic Chemistry (Clarendon Press, Oxford, U.K. 1986), p. 279

Study on Composite Properties of a Novel Unsymmetrical Diarylethene with Benzene Unit Weiwei Geng, Shiqiang Cui and Shouzhi Pu* Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, P.R.China pushouzhi@tsinghua.org.cn Keywords: Diarylethene; Photochromism; Fluorescence switching; Optical recording Abstract.
The photochromic process of diarylethenes is based on a reversible transformation between the open-ring isomer with a hexatriene structure and the closedring isomer with a cyclohexadiene structure, according to the Woodward–Hoffmann rule [10].
The open-ring isomer is colorless in most cases, while closed-ring isomer shows some color depending on the molecular structures [11].Among the photochromic compounds, diarylethenes are regarded as the best candidates for such devices, because of their advantages such as a high efficiency of photoisomerizations, sufficient thermal stability of both the open and the close forms, a very high resistance to photofatigue, and the ease with which the reaction can be monitored by UV-Vis spectroscopy [12-13].
The structure of compound 1a was confirmed by 1H NMR spectroscopy. 1H NMR (400 MHz, CDCl3, ppm): δ1.94 (s, 3H, -CH3), 4.07(t, 4H,-OCH2-CH2O-), 7.14(s, 1H, thiophene-H), 7.68 (d, 4H, benzene-H). 9.83 (s, 1H, -CHO), 7.29 (d, 1H, J = 8.0 Hz, benzene-H).

In the chemistry fields, it can be used to analyze the effectiveness and structure of some chemical medicine.
Therefore some factors such as the purpose of evaluation, the structure of the whole performance, the targeted performance effects and the basic structure of the contents of the performance are the evaluation factors.
In a musical performance, a evaluation has been make though the comprehensive evaluation method and the result can be reflected as follows: Weight coefficient Evaluation factors Good Relatively good Normal Below normal standard Very bad 0.15 Purposes and requirements 0.3 0.3 0.2 0.1 0.1 0.25 Performance method 0.5 0.2 0.1 0.1 0.1 0.15 The structure of the whole tune 0.4 0.2 0.2 0.1 0.1 0.25 procedures 0.5 0.2 0.1 0.1 0.1 0.20 The performer’s attitude and quality 0.4 0.3 0.1 0.1 0.1 Fig.1 The comprehensive evaluation method and the result After the above step, the next step is to deal with the data and calculate the comprehensive judgment value B.

The microwave-assisted synthesis and gas sensing properties for ethanol of SnO2 nanomaterials Yongju Liu2,a, Qiuping Jiang1,b, Yuehuan Li3,1,c, Heyun Zhao1,d,* 1Department of Materials Science and Engineering, Yunnan University, Kunming 650091, China 2Advanced Analysis and Measurement Center of Yunnan University, Kunming 650091, China 3School of Pharmacy and Chemistry, Dali University, Dali 671200, China ayjliu@ynu.edu.cn, bqiuping26@yahoo.cn, cloneman2@163.com, d,*hyzhao@ynu.edu.cn Keywords: Tin oxide; Nanostructures; Microwave-assisted; Sensing property Abstract.
An indirect heating structure is selected to prepare sensors.
Results and Discussion The crystal structure of the product was firstly characterized by XRD.
All diffraction peaks can be indexed to the rutile structured SnO2 (tetragonal, P42/mnm) with tetragonal lattice parameters of a=b=4.738 Å and c=3.186 Å, which match well with the standard data file of SnO2 crystal (JCPDS file No. 41-1445).
Microwave-assisted synthesis of hexagonal structure ZnO micro-tubes, Mater.

Figure 1 shows the molecular structure.
There are some characters in L-proline such as the rigid ring structure, easy availability, lack of toxicity, and inexpensive amino acid.
Figure 1 Structure of L-proline Ion-exchange process is used to separate the mixture of L-proline and L-hydroxyproline during the protein hydrolysis of celluloid, because of their similar structure and properties.
Sandaroos, l-Proline-catalyzed three-component synthesis of condensed imidazoles, Arabian Journal of Chemistry

This implies the usefulness of the PLD as a method of thin film deposition for complex chemistries of compounds.
The crystal structure of the thin film samples were investigated using Grazing Incident Diffraction (GID) technique via an X-ray diffractometer (Bruker D8 Advance) with Cu Kα radiation.
XRD patterns for (a) J1 (b) J2 and (c) J3 films The effects of different chamber pressures and different kinds of targets are different on crystal structure, morphology and thickness of the MgO films.
The XRD patterns were referred to the ICDD reference pattern number, 01-087-0651, which show a cubic structure belonging to the space group Fm-3m.
This finding shows that different chamber pressures and targets affect the crystal structure of MgO thin films.

For improving the image quality, some fabrication process of anode pixels on the anode plate should be considered, and the manufacture structure of anode pixels would also be designed according to the real process [10].
Fig.1 The schematic of anode pixels for the FED panel In Fig.2, the schematic structure of whole diode FED panel was given.
Fig.2 Schematic structure of whole diode FED panel Results and discussion For the diode FED panel, the anode plate might be one of the important and complicated elements, not only because the panel image would be displayed on it, but also because the vacuum chamber would be formed by it.
The anode pixels structure mainly was composed of four parts, which were the anode electrodes, the insulation layer, the phosphor layer and the peripheral connecting line, respectively.
Materials chemistry and physics.

Low Temperature Synthesis and Luminescent Properties of Ca2SnO4: Eu 3 LI Yuzhong1, a, Zhou Xiaochun 2, b 1 Key Laboratory of Numerical Control Technology of Guangdong Higher Education Institutes, Mechanical and Electronic Department of Guangdong Polytechnic Normal University; Guangzhou 510635, China 2 School of Chemistry and Chemical Engineering, Jinggangshan University, Ji'an 343009, Jiangxi, China a Liyuzh@gdin.edu.cn, bncdxzxc@163.com Keywords: Ca2SnO4: Eu3+; Luminescence; Low temperature solid state reaction; Intensity ratio.
The luminescent properties of phosphors are strongly dependent on the crystal structure of host materials.
Results and Discussion XRD was used to examine the crystal structure and phase purity of the products and the typical XRD patterns of the 0.01 mol of Ca (NO3)2 · 4H2O co-doped synthesized Ca2SnO4: Eu3+ samples are shown in Fig.1.
All mainly reflections in the patterns corresponding to orthorhombic crystal system structure Ca2SnO4, and this observation indicates that the mainly phase of Ca2SnO4 was completed by the low temperature (at 740 °C) solid state reaction, this may be ascribed to the synthesis of H2SnO3 and effects of low temperature solid-state reaction.
The larger 5D0 → 7F2 / 5D0 → 7F1 intensity ratio indicates that the point symmetry of Eu 3+ site is closer to an inversion center, and at the same time, the plausible explanation to the much larger 5D0 → 7F2 / 5D0 → 7F1 intensity ratio is that Ca2SnO4 has an orthorhombic crystal system structure with low symmetry, when Eu 3+ ions are doped in the Ca2SnO4 host, according to regulations of radius, Eu 3+ (0.101 nm), Ca2+ (0.099 nm), Sn4+ (0.071 nm), Eu3+ could occupy Ca2+ sites, thus, the excellent red emission transition 5D0 → 7F2 has been found to be more prominent for Eu 3+ ions Fig.3 SEM images of the as-prepared Ca2SnO4 : Eu3+ Fig. 4. spectrum of the as-prepared Ca2SnO4: Eu 3+ : (a) excitation (em = 615 nm); (b) emission (ex = 395 nm) Conclusions In summary, a novel red phosphor Ca2SnO4: Eu 3+ has been synthesized by low temperature solid state reaction.

In nature, pure PPy with benzoid structure is an insulator and it needs to be doping with oxidant in order to work as a semiconductor.
It can be seen that no sharp peak was observed in the range of 1-40˚ which corresponded to the amorphous structure of PPy [12].
A broad halo pattern around 25˚ is related to PPy and it is typical for doped structure of polypyrrole [13].
Broad peak or no sharp peak manifested that no crystalline structure was formed in the sample.
Duic: Journal of Polymer Science Part A: Polymer Chemistry Vol. 30(8) (1992), p.1609 [5] C.

Adsorption and removal of Congo red dye from aqueous solution by using nano-Fe3O4 Zhuxing Tang1,a, Yin Chen1,b, Jun Xue1,c, Shuang Yue2,d 1College of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang, 110159, China 2Institute of Rare and Scattered Elements Chemistry, Liaoning University, Shenyang, 110036, China azxingtang@yahoo.com.cn, bchenyanjun0317@126.com, cjunyyan87417@sina.com, dyueshuang200@163.com Keywords: Fe3O4 nano-particles, Congo red, Adsorption, Removal.
A variety of crystal phase composed of single-phase have particular crystal structures and X-ray diffraction pattern features, so we could examine their purity and crystal structure by comparing all the peaks of nano-Fe3O4 samples with standard single-phase material diffraction peak.
The crystal structure of nano-Fe3O4 was characterized using XRD for 2θ diffraction angles from 20° to 90°.
The results show the sample is nano-Fe3O4 which has high purity and well-crystallizes structure.