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Introduction Piping system as the basic components to transmit fluid is widely applied in oil, chemistry, civil engineering, aviation and so on.
In recent years, research on the effect of liquid-structure coupling interaction on vibration characteristics of pipes conveying liquids is becoming highly valued and Michigan State University[2] in the United States proposed some mathematical models used to described liquid-structure coupling through model analysis with commercial software.
But in China, most researches were limited to linear vibration of pipe and ofen ignore the effect of liquid-structure coupling.
Modal analysis of pipeline connected with centrifugal pump outlet Fig.1 The dimensions of pipeline connected with centrifugal pump outlet The structure and dimensions of pipeline are illustrated in Fig. 1.
Through harmonic response analyse, continuous dynamic characteristics of structures can be predicted by designer, then can be used to confirm the design of pipeline whether or not to overcome fatigue breakage or other breakages caused by forced vibration.

Bioactive titanium with the specific surface crystalline structure of anatase was shown effective for apatite formation in vitro study.
AO Ti plates, prepared in 1M 1M H2SO4 at 155v DC with the specific surface structure of anatase, have showed higher ability of apatite formation in vitro study.
The porous structure of the treated layer remained at all time intervals.
It is postulated that due to the specific crystalline anatase structure of titanium surface, that apatite is formed on the surface of titania gel in vitro [11].
In the current study, when the crystalline anatase structure was formed on the surface with the anodic oxidation treatment, it has shown effective bioactive performance and directly bonded to the bone in vivo.

With the development of nano materials, a novel research field of NEMS forms by combining nano materials, nano-structures and nano fabrication with MEMS.
Carbon nanotube (CNT) is a kind of one-dimensional nano structures which has unique mechanical, electrical and chemical properties.
Through fluidic channel structures formed between a poly (dimethylsiloxane) (PDMS) mold and a flat substrate, parallel and crossed arrays of nanowires can be readily achieved.
Fig. 7 AFM manipulation of a single multi-wall nanotube [11] Multi layers structure using LBL.
The Journal of Physical Chemistry Part B 108(2004), 4385-4393

The dependencies developed were used to establish the requirements for process conditions of the geopolymer construction products and structures production.
One of the key elements of binder structure formation is kinetics of its hardening [11-13].
Investigation of influence of various factors on hardening kinetics is one of the methods to study the structure formation [12, 14, 15].
One of potential reasons for the structure defects occurred in the hardening material is stresses resulted from irregular compaction of the structure.
Davidovits, Geopolymer chemistry and applications, Geopolymer Institute, Saint-Quentin, 2015

Fig.6b corresponds to the layer structure of different compounds on the grain surface.
The special layer structure has two advantages for good transitions of chemical bonds and thermal expand coefficients.
At the annealing temperature of 950˚C for 60 min, there exists a sandwich structure of CBN/TiB2/TiB/(TiB+TiN)/Ti, which possesses the obvious transitional effects in terms of the chemical bonds and could provide strong adhesion between CBN grain crystal and surface Ti film.
The preliminary thermodynamic analysis has also discussed the formation mechanism of the special transition structure.
Materials Chemistry and Physics 2002; 77: 236.

The structure, textural properties and chemical composition of surface were studied using SEM, Raman spectroscopy, adsorption (BET) and XPS.
The carbon fibers produced on SOCs were shown to be characterized by unique segmental structure [5, 8].
Structure of CNF samples was studied by Raman spectroscopy.
The carbon product is seen to be represented by the filaments with distinct segmental structure (Fig. 1C).
It is worth to note that the subsequent treatment in HNO3 does not practically affect the structure of the pristine CNF material.

Owing to the low magnification the lamellar structure is not resolved in the BSE images.
Most of them have a average lamellar spacing of 700 nm as that of cast structure (Fig.3b).
The newly formed twins decrease the lamellar spacing of the residual cast structure.
Thus, residual cast structure exhibit different lamellar spacing.
Forging induces not only grain refinement of the cast structure but also chemical and microstructural homogeneity.

Simulation theory The absorbing performance of CH3+ radical on Si (111) was investigated by CASTEP, the quantum mechanics method and density functional theory (DFT) to study the surface chemistry, bond structure, density of states, optical properties, electron density difference and the wave function.
Its model structure is closely similar to real material and can make the results more reasonable.
The optimized results showed that CH3+ and Si atom bonding structure is different on the different adsorption position, i.e.
Compared Si (111) of before and after absorbed surface can get structure changes, bonding and properties change.
We also compared the molecular structure change of CH3+ radical.

Mangeron 53, 70050 Iasi, Romania 2Romanian Academy, “Petru Poni” Institute of Macromolecular Chemistry, 41 A Gr.
The effect of amount and type of compatibilizing agents is evaluated using electronic microscopy and dielectric spectroscopy, to obtain the optimum materials structure.
Compatibilizers, which reduce the interfacial tension and stabilize the dispersed structure, can be added to improve the properties of polyethylene/polyamide blends [1].
This can be explained by a more homogeneous structure of the mixture.
Spectra collected using dielectric spectroscopy provides valuable information about the structure of mixtures.

An additional hf structure due to the interaction with two equivalent Si neighbors was also observed.
In 3C-SiC with cubic crystal structure, calculations [1] found that 3d TMs prefer the Si site to form substitutional impurities.
Therefore, the observed hf structure can be unambiguously identified to be related to Nb.
In our preliminary EPR study of Nb-doped 6H-SiC, we also observed only one EPR spectrum of C1h symmetry and similar hf structures.
Based on the obtained hf structure, the spectrum can be unambiguously identified to be related to 93Nb.