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Synthesis and Properties of a Novel Unsymmetrical Diarylethene with Five and Six Ring Aryls Weiwei Geng, Shouzhi Pu*, Shiqiang Cui Jiangxi Key Laboratory of Organic Chemistry Jiangxi Science and Technology Normal University Nanchang 330013, P.
The photochromic process of diarylethenes is based on a reversible transformation between the open-ring isomer with a hexatriene structure and the closed ring isomer with a cyclohexadiene structure, according to the Woodward–Hoffmann rule [7].
The open-ring isomer is colorless in most cases, while closed-ring isomer shows some color depending on the molecular structures [8].
The structure of compound 1a was confirmed by 1H NMR spectroscopy. 1H NMR (400 MHz, CDCl3, ppm): δ1.98 (s, 3H, -CH3), 4.07(t, 4H,-OCH2-CH2O-), 7.07(s, 1H, thiophene-H), 7.59 (d, 1H, benzene-H), 7.65 (t, 2H, benzene-H)，7.61（d，1H, benzene-H）. 7.29 (d, 1H, J = 8.0 Hz, benzene-H).
Liu, Novel photochromic macrocycles composed of thiophene and ethylene building blocks: synthesis, structure, and photochromic property, Tetrahedron Lett. 49 (2008) 1582-1585

Introduction The mechanical properties of the metal welded seal are strongly affected by the structures of the wave.
In order to improve the life-span and durability of the metal welded bellow, the structure of the bellow wave should be improved.
The reaction-diffusion model was firstly proposed by Turing and has been studied in various fields, such as chemistry and biology[3].
Numerical Results of Shape Optimization The structure of the metal welded bellow seal is given as the Fig1.
This is indicated that the stress concentration largely reduced and the optimized structure close to uniform stress distribution model is obtained.

Results and Discussion The optimized structure of dopamine is shown in Figure 1(a) and the fullerene C60 is given in Fig 1(b).
The X-doped fullerene structures are given in Figures 1(c) (X=Si), Figure 1(d) (X=Sn), and Figure 1(e) (X=BN).
Optimized structures: (a) dopamine; (b) C60; (c) C59Si; (d) C59Sn; (e) C58BN. 3.501 Å (a) 1.939 Å (b) 3.120 Å (c) 4.781 Å (d) Fig. 2.
Optimized structures: (a) dopamine with C60; (b) dopamine with C59Si; (c) dopamine with C59Sn; (d) dopamine with C58BN.
[19] Sholihun, Kadarisman, H.P, Nurwantoro, P, Indonesian Journal of Chemistry. 18(4) (2018) 749–754

Introduction Nano-scale materials show especial physical and chemical characteristic because of the quantum size effect, the surface effect and the macroscopic quantum effect, so that brought about many new research opportunities in physics, chemistry, material science, biology etc. [1].
The uniformity in the size distribution without any size selection processes is attributed to the presence of TOP and PVP, since TOP is a high-boiling point surfactant with a patulous chain structure and PVP has a large molecular weight (~1,300,000) and a long chain structure.
It is viousbly that TOP has an effect on particle size with a patulous chain structure.
As the particle size increased from 4.2 to 34.2 nm, the particles showed more clear crystalline structure of magnetite, according to selected-area electron diffraction (SAED) patterns taken with the TEM as shown in the insets of Fig. 1.
The concentration of PVP had an important effect on particle size due to its large molecular weight and a long chain structure.

Research on Hydrogen Bonding Interaction of Trigonal Schiff Base Compound with Barbituric Acid in Organized Molecular Films Tifeng Jiao1,2,a and Jingxin Zhou1 1Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei, 066004, China 2State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, Gansu, 730000, China atfjiao@ysu.edu.cn Keywords: Trigonal Schiff base, Hydrogen bonding, Barbituric acid, LB film, Supramolecular assembly, Spectral measurement.
First, some research works on the hydrogen bond between Schiff bases and barbituric acid was reported [8-10], but it is still interesting to investigate effect of molecular structure on hydrogen bonding.
The introduction of trigonal molecular structure into the present Schiff base compound can lead to more flexible structure and new properties are expected.
The structure of final product is shown in Fig. 1, abbreviated as C18TSB, which was confirmed by 1H NMR.
Chemical structure of trigonal Schiff base compound C18TSB.

By using wet etching, the structure of GC column is hard to control accurately.
In this experiment, separation columns were etched by using deep reactive ion etching (DRIE) technique to form a structure of 1m-long, 90um-wide, and300um-deep rectangular channel.
The Figure 2 shows the structure of GC column.
[2] L.Wang, X.S.Du, J.Hu; Research Progress of Structures for MEMS Gas Chromatography Columns; Weina Dianzi Jishu(Micronanoelectronic Technology), 2011, 48(10): 639-647
Sensenig; Design, fabrication, and evaluation of microfabricated columns for gas chromatography; Analytical chemistry, 2004, 76(9): 2629-2637

The σ-phase has a brittle and stable structure and usually occurs at grains boundaries.
The σ-phase has a complex structure with a tetragonal unit cell (sp. gr.
The σ-phase structure with 30 atoms distributed over 5 crystallographically inequivalent sites (A,B,C,D,E) in the unit cell.
The calculated structure has a positive value 5 kJ/mol of the formation enthalpy, which agrees well with the calorimetrically determined enthalpy of formation of 6.5 kJ/mol [15].
This may play a role in the structure formation.

They display a variety of structures and can be largely divided into two groups.
View of NdPO4 structure along the c-axis.
The crystal structure of NdPO4, as seen along c-axis, is shown in Fig.1a.
Protonic conduction in rare earth orthophosphaters with monazite structure.
Structural refinements of praseodymium and neodymium orthophosphate Journal of Solid State Chemistry. (1985), 57, 71-77 [12] S.

Usually, the A-site cations of perovskites stabilize the crystal structure while B-site cations are active.
It is also found that the cell volume has its maximum value when x=0.1 while the crystal structure undergoes a change from YFeO3 to YMnO3, leading to the surface oxygen vacancies of perovskite structure.
However, the perovskite structure remains unchanged.
Ideal perovskite ABO3 structure belongs to Oh group.
The spectrum band r1 and r2 can be seen in the infrared spectroscopy of this structure.

Fabrication of Ti2AlN by Mechanical Alloying and Hot Press Sintering Jianfeng Zhua, Na Han, Kun Wang and Fen Wang Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an 710021, China a zhujf@sust.edu.cn Keywords: Ti2AlN; Mechanical Alloying; Hot Press; Layer Structure.
Though the diffraction angles are shifted, it can still be seen that the diffraction peaks of the MAed powders are corresponding to that of Ti both in the relative peak positions and intensities, which implies that the elements of Al and N dissolve into the Ti structure to form Ti(Al,N) supersaturated solid solution in a non-equilibrium state.
Because the Al atom size of 0.286 nm is smaller than the Ti atom size of 0.291 nm, according to Bragg’s law of 2dsinθ=λ, where λ is the X-ray wave length, the lattice parameter and the inter-planar spacing d in the Ti crystal structure is reduced when Al atom replace for Ti atom, so the Ti diffraction peaks shift to the high angle.
It can be seen clearly that Ti2AlN phase was well developed with a close and lamellated structure. the distribution of Ti2AlN grains was homogeneous.The grains were plate-like with the sizes of 1-5 μm in thickness and 5-10 μm in elongated dimension, respectively.
When sintered at 1200 °C, Ti2AlN phase was well developed with a close and lamellated structure.