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The microscopic structure of the silicon vacancy related centers was subject to a long-standing debate.
Electronic Structure of Isolated Silicon Vacancy in SiC Besides the structure, the charge and spin state of the V1-V2 and V1-V3 centers in 4H and 6H-SiC, respectively, were subject to long-standing scientific debates.
Electronic structure of the isolated negatively charged silicon vacancy at the k site in 4H-SiC.
(a) Structure and spin density of the defect.
(b) Tight binding electronic structure of the spin-3/2 ground state.

The basic structure of nano materials determines that they have strong adsorption capacity.
These multifunctional properties are widely used in the fields of chemistry, physics, electronics, biology, device storage, medicine and environmental improvement [3].
Graphene is a two-dimensional periodic honeycomb lattice structure composed of carbon six membered rings.
Carbon nanotube is a one-dimensional hollow tubular structure formed by the axial curling of graphite sheets.
[11] Han Core-shell structured Fe;O/PANI microspheres and their Cr(VI) ion removal properties 171:1-6.

Brawijaya, Kasihan, Bantul, Yogyakarta 55183, Indonesia. 2Department of Chemistry, State University of Jakarta, Jl.
Scanning electron microscopy (SEM) results revealed that beads-free fiber structure featured in all electrospun membranes with relatively homogeneous fiber size distribution.
SEM micrographs (Fig.1) illustrate the bead-free fibrous structure for all electrospun PVA_AV/CSNe nanofiber membranes.
The highest tensile strength can also be understood from the typical structure of the membrane (Fig. 4), showing the interaction between the fibers which generated high volume fraction of cross-link structures (see arrows).
This typical structure seems to be beneficial in improving the tensile strength of the membranes.

In fact, if the LOCA occurs on structure already damaged by early age cracking or endogenous chemical reactions, such as AAR or ettringite, the leakage risk could be increased.
A last problem, already observed in North America, concerns the concrete chemistry: in fact the cement paste and the aggregates of concrete can evolve chemically since the vessel construction.
In a large structure, the first cracks appear under stresses lesser than the tensile strength measured with usual laboratory tests (such as split test or direct tension test).
B4014002 [7] Ladaoui W, Vidal T, Sellier A and Bourbon X 2010 Thermal activation of basic creep for HPC in the range 20°C 80°C Computational Modelling of Concrete Structures (CRC Press) pp 513–8 [8] Buffo-Lacarrière L, Sellier A, Turatsinze A and Escadeillas G 2011 Finite element modelling of hardening concrete: application to the prediction of early age cracking for massive reinforced structures Mater.
Inst. 105 227–35 [13] Grimal E, Sellier a., Multon S, Le Pape Y and Bourdarot E 2010 Concrete modelling for expertise of structures affected by alkali aggregate reaction Cem.

A temperature increase above 300 °C further damages concrete structure by the formations of cracks.
Since the low permeable structure of HPC does not allow escaping moisture from the heated structure of concrete, pore pressures arise.
Therefore, concrete structures are often reinforced by the various types of fibres in order to decrease crack formation and improve its mechanical properties.
The analysis of pore structure of examined materials was done by Mercury Intrusion Porosimetry (MIP).
These results clearly documents changes in the concrete structure due to the decomposition and dehydration of the hydrated products.

Efflorescence easily disperses from the capillaries of porous structures in geopolymer specimens, reducing their compressive strength, and spalls the structure of hardened specimens.
The magnetic formation of dendritic structures on the surface of the fly ash was scrutinised on the 90 d specimen.
This dendritic structure was influenced by iron oxides formed during the oxidation that transformed Fe2+ to Fe3+.
Nevertheless, this structure increased glass concentration and blocked other elements, such as Si, Al, K, Na, and P from entering the spinel structure, thereby affecting the quality of the geopolymer structure ultimately produced [19].
Industrial & Engineering Chemistry Research. 45, 3559-3568

Not only used popularly as external bonded reinforcement for the retrofit of structures, but FRP composite can also be used to exploit new construction due to the excellent properties of FRP above.
FRP strengthened RC structures, Wiley, New York
Chemistry Industry Press (2000), Beijing, China (in chinese)
Engineering structures.

The materials have different particle geometry, size, and different surface structure, as shown in Fig. 1.
A diffusion of boron atoms into the surface structure of the graphite particles during the microwave plasma process would be an explanation for the higher values of specific capacity.
Peebles: Carbon fibers - Formation, Structure and Properties (CRC Press, USA, 1995), p.155-176 [6] E.
Yin et al.: Materials Chemistry and Physics 80 (2003), p. 94-101 [12] S.H.

Deposition mechanism study of a novel electroless nickel plating technique on AZ91D magnesium alloy Jiangang Qian1, a, Tian Zhao1, b 1 School of Chemistry and Environment, Beihang University, Beijing, PR China 100191 aqianjg@buaa.edu.cn, bzhaotian63@sina.com Keywords: AZ91D magnesium alloy; Electroless nickel plating; Deposition mechanism Abstract.
As seen in Fig.1a, after alkaline degreasing, the surface structure of magnesium alloy was uniformly granular and had no impurities.
A honeycomb-like structure appeared on the surface of the specimen as shown in Fig.2d.
With the further growth of the plating layer, this honeycomb-like structure was gradually covered by growing cellular particles.

The fluorescent and photovoltaic properties of meso-teraphenyl porphyrins with different substituents Wei Yin1, a, Huanbao Fa1,b, Changguo Chen1,c , Liping Zhang1,d 1 College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, China ayinweicqu@163.com, bhuanbaofa@163.com, ccgchen@cqu.edu.cn,dhmzm0501@163.com Keywords: Fluorescence; Surface Photovoltage; porphyrin; Substituent Abstract.
However, very few persons have researched systematically the relationship between the structure and the fluorescence property or surface photovoltage property of porphyrin.
Structures of different meso-substituted free base porphyrins Experimental Preparation Compounds 1, 3 and 4 were synthesized as described in Ref [10, 11, 12], and 5 were synthesized as described previously [13], Compound 2 were synthesized as follows: A solution of 200 mg of porphyrin 1 in 100 ml of dried dichloromethane was stirred in ice-salt bath condition for 20 min and the ensuing solution was stirred for 12 h after the addition of 100 mg of N, N’ -dicyclohexylcarbodiimide.
For 1, 2 and 4, the symmetry structures had been destroyed owing to the introduction of substitutes.