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Introduction Utilization of shell and tube heat exchangers are predominant in petroleum field, chemistry industry, oil refining and uses of nuclear power due to its versatility, simple structure, low cost and convenient cleaning.
After models of both the new type helical baffles heat exchanger and segmental baffles heat exchanger with same geometric structure were set up ,numerical simulation was undertook in its shell side flow and heat exchange characteristic by CFD method[5].
(a) (b) Fig.5: (a) Pressure drop and heat transfer rate versus mass flow rate (b) Heat transfer rate under unit pressure drop versus mass flow rate Conclusion In this paper, the shell side of helical baffles heat exchangers on heat transfer characteristics analysis with numerical simulation method, comparing with segmental baffle board heat exchangers which have the same geometry structure.

Introduction Interaction features of matter and field at different region of spectrum are used in science, factory and laboratory practices for research of properties, determination of structure, consist and control specified properties.
This can be explained by the changed structure of melt water.
We have identified it as the temperature at which there is a sharp decrease in the real and imaginary part of the permittivity, which corresponds to change in structure of the liquid during the transition to a different aggregate state.
Dielectric properties of D2O ice in the microwave range, Russian Journal of Physical Chemistry, 75, 5 (2001) 834 – 836

China 2 Engineering Research Center of Jilin University Super Engineering Plastics, Ministry of Education, College of Chemistry, Jilin University, Changchun 130012 P.
The structure of the poly(aryl ether sulfone)s were characterized by IR spectroscopy and elemental analysis, and the results were in good agreement with the expected structures.
The glass transition temperatures (Tg) for the poly(aryl ether suflone)s prepared from a-c and HQ, BPS, BPA were 220, 224, 226, 219, 236, and 227oC, respectively, which is in accord with expectations based on their molecular structures.

The chocolate B clay was efficient in the formation of the molecular sieve structure, but there was a great reduction in the surface area and total pore volume in comparison to the surface area of classic SBA-15.
The first sieve is a hexagonal array of parallel tubes called MCM-41, the second sieve, MCM-48, is formed by tubes arranged in a cubic pattern, and the third structure is a not stable lamellar solid, named MCM-50 [4].
The molecular sieve SBA-15 is a mesoporous silicate class, characterized by uniform tubular pores, structured in hexagonal arrangement of channels, with higher thermal stability than M41S, high degree of structural order, surface area of 500-1000 m2/g of wall thickness and larger pore diameters than the characteristical pore structure of MCM-41 [2].
Both SBA-15 (Fig. 3 and Fig. 4) checks the presence of the peak formed on plans Miller (1 0 0) characteristic of the formation of the mesoporous structure.
Rodrigues: Journal of Natural Gas Chemistry Vol. 21 (2012), p. 722 [6] D.

Since it is difficult to identify the microscopic structure of the zeolite membrane using experimental approaches, it is necessary to investigate the diffusion behaviour of molecules and ions through the zeolite with the aid of computer.
In this study, the aluminosilicate MFI zeolite system (Si/Al = 191) is adopted and the grand canonical Monte Carlo (GCMC) method is used to predict the water absorption into aluminosilicate MFI zeolite structure under various conditions of pressure.
One sodium ion was initially placed near the aluminumdoped sites, and the full structure of zeolite frame including the sodium ions was energy minimized.
After creating the zeolite structure, the total accessible volume was calculated by using the “Connolly surface” method [7].
Conclusions In this study, the aluminosilicate MFI zeolite system (Si/Al = 191) and the grand canonical Monte Carlo (GCMC) method were adopted to predict the water absorption into aluminosilicate MFI zeolite structure under various conditions of pressure.

Scanning electron microscope (SEM) of poly (3-bromothiophene) shows that its morphology is nano-wire structure.
Meanwhile, polythiophenes have attracted a great deal of attention due to their wide use in many fields as conductive polymers, such as conductive fiber, sensors, rechargeable batteries, high-power capacitor and nano-structure.
One of the main limiting parameters to improve the PCE is the morphology of polythiophenes, such as nano-structure.
Nano-structure, as one kind of morphology of polythiophenes, has a significant effect on the improving of the PCE [8-11].
In this work, we report the preparation poly (3-bromothiophene) with nano-wire structure and the investigation of its photo/electrochemical properties. 2.

Nanotechnology is a future manufacturing technology giving thorough, inexpensive control of the structure of matter.
It is surprising that its electronic structure can be either metallic or semiconducting, depending on the chiral angle.
Solution chemistry uses random thermal motion of thermodynamics to fit atoms to the required location.
Chemistry is a not too elegant way of bottom-up building.
Nevertheless, chemistry can be a useful and efficient tool in nanotechnology making basic materials, nanocrystals and nanolayers with chemical methods.

Instruments and Experimental methods.The flowing cell in the experiment was self-made and the effective volume is about 1mL[28] and the detailed structure shown in Fig. 1.
The specific recognition between aptamer and its target molecule is dependent on the formation of three-dimensional structure of its single-chain nucleotide molecule.
The specific recognition between aptamer and its target molecule is dependent on the formation of three-dimensional structure of its single-chain nucleotide molecule.
Yu: Chinese Journal of Analytical Chemistry, vol. 37(2009), p. 1596
Ji: Analytical Chemistry, vol. 74(2002), p. 3611

CBN composites sintered at high pressure and high temperature are used widely as cutting tools for many hardened steels because CBN of a zinc blende structure possesses excellent hardness and chemical stability necessary for cutting steels.
The GCr15 bearing steel was selected for the workpiece materials with the average hardness HRC60±2, and the microstructure was acicular martensite, carbides and a small amount of residual austenite, Table 1 chemistry components of GCr15 bearing steel.
Fig.1 SEM morphology of PCBN Table 1 Chemistry components of GCr15 bearing steel[wt%] Element C Si Mn P S Cr Ni other Content 0.95-1.05 0.15-0.35 0.20-0.40 <0.027 <0.020 1.30-1.62 <0.30 Cu<0.25 The cutting experiments were conducted on the CA6140A lathe, and the geometry parameters of the PCBN cutting tool was γo= 0°, ao=6°, λs =0°, κr= 93°, κr′= 5°, nose radius rε=0.8mm, negative chamfer was -15°×0.2mm, the cutting conditions including that cutting speed Vc=200m/min, depth of cut ap=0.1mm, and the feed rate f=0.05mm/r.

MacCallum 2 1 IBQF, Universidade do Minho, 4700-320 Braga, Portugal 2 School of Chemistry, University of St.
Variation of Tg and decomposition temperatures of selected p(TMC)n LiAsF6 electrolytes as a function of salt composition In this respect the salt, dissolved in the polymer matrix, probably perturbs the structure of the polymer, creating free volume, which facilitates the local motion of polymer chain segments.
Gray: Polymer Electrolytes, RSC Materials Monographs, Royal Society of Chemistry, London, 1997