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1

Wpływ mielenia strumieniowego na strukturę i fizyczno-chemiczne właściwości skrobi kukurydzianej o dużej zawartości amylozy

Wang L., Liu T., Cou F., Xiao Z., Cao L.

Przemysł Chemiczny

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2017

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T. 96, nr 5

1128--1134

PL

Skrobię o dużej zawartości amylozy HAMS (high-amylose maize starch) modyfikowano, stosując mielenie strumieniowe, a następnie badano jej strukturę molekularną i właściwości fizyczno-chemiczne metodami skaningowej mikroskopii elektronowej, dyfraktometrii rentgenowskiej, spektroskopii w podczerwieni z transformacją Fouriera, skaningowej różnicowej kalorymetrii, a także za pomocą laserowego analizatora wielkości cząstek oraz szybkościowego wiskozymetru. Stwierdzono zmianę postaci mikronizowanych ziaren skrobi. Stały się one małe, nieregularne i szorstkie. Przeciętna średnica ziaren zmalała z 14,62 μm do 6,14 μm, przy czym rozrzut wielkości ziaren stał się wąski i regularny. Krystaliczna struktura skrobi uległa przemianie do typu B, a krystaliczność produktu zmalała z 34,63% do 24,19%. Mielenie nie spowodowało powstania żadnych nowych grup funkcyjnych. Temperatura kleikowania mikronizowanej skrobi zmalała (zarówno temperatura początkowa, maksymalna, jak i końcowa), co wynikało ze znacznych zmian termodynamicznych właściwości mielonej skrobi. Zmniejszeniu uległy również wartości lepkości maksymalnej końcowej, lepkości w warunkach rozkładu, jak i lepkości powrotnej mikronizowanej skrobi. Skrobia taka wykazywała lepszą stabilność lepkości i mogła być przerabiana przy większych lepkościach.

EN

Grains of high-amylose maize starch (HAMS) were disintegrated (micronized) by jet milling with compressed air to alter their structure and properties. The disintegration resulted in decreasing the particle size in av. from 14.62 μm down to 6.14 μm, in changing the particle shape to an irregular one and crystal structure to the B-type. After jet milling, the particle distribution curves become narrow and uniform but the grains lost their smoothness and become rough. Their crystallinity decreased from 34.63% down to 24.19%. The milling did not result however in formation of any new functional groups. The enthalpy of thermal transition decreased after the milling. All pasting temps. and sp. viscosities of micronized HAMS pastes alsodecreased but they shower a better viscosity stability and could be processed to the higher viscosity than the pastes of native HAMS.

2

Calculating study of the turbine at last stage flow field in the small volume flow condition

Jiang T., Jin J., Wang Z., Cao L., Li B.

Polish Maritime Research

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2017

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S 3

23--27

EN

Based on basic equation and boundary layer theory of pneumodynamics, the thesis conducts numerical modeling and theoretical analysis on the last stage of turbine characteristics at a small volume flow by using FLUENT, gives an emphasized analysis on the position of first occurrence of backflow and its expansion direction and comes up with flow structure of the turbine flow field at last stage in the small volume flow condition. In connection with specific experiments, it puts forward the flow model of backflow occurring in the last stage field and the solution to the model. The flow field at last stage for a 100MW turbine in the small volume flow condition that is calculated by using the model is basically in conformity to the actual result.

3

Significance of Stump-Sprouting for the Population Size Structure and Spatial Distribution Patterns of Endangered Species, Magnolia cylindrical

Li J., Wu Y., Wu T., Cao L., Chen J., Qiu Z., Zhang Y., Xu G., Zhang J., Liu P.

Polish Journal of Ecology

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2017

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Vol. 65, nr 2

247--257

EN

Magnolia cylindrica Wils. is one of the third most-protected wild plants in China. To describe the size structure and dynamics of its population, field data were obtained from eight newly established sites, using a contiguous grid quadrate method in Jiulong Mountain of East China. The population size structure and spatial distribution pattern were discussed based on a theoretical distribution model and assembling intensity index. The population size structure showed a declining trend because of the lack of seedlings. The number of stump-sprouting, size class III (sapling trees) individuals was large enough to make up for the shortage of small seedlings and the complete regeneration of populations through sprouting. The distributions of M. cylindrica, both seedling populations (Group A) and overall populations (Group B), were mostly clumped. The spatial pattern intensities of the populations at different stages (mainly small trees, middle trees, and big trees) were higher for Group A than those for Group B. The two groups have the same tendency in that the pattern intensity declined from small trees to the larger ones. Group A and Group B differed in spatial pattern: small and middle trees were randomly distributed in seedling populations, but aggregated in overall populations. The populations of M. cylindrica (both group A and B) were characterized by the pattern scale between 16 to 32 m2, measured by Greig-Smith and Kershaw methods. These results suggest that sprouting should be seriously considered in population rehabilitation and forest tending management and the area of forest tending management should be close to the maximum intensity.

4

Numerical analysis on the influence of the twisted blade on the aerodynamic performance of turbine

Jin J., Wang Z., Cao L.

Polish Maritime Research

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2016

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S 1

86--90

EN

With the gradual increase of the thermal power unit capacity, the inlet steam parameters and flow of the turbine also increase gradually, which causes considerable secondary flow loss. Therefore, studying the causes and distribution of secondary flow loss within the level is of great significance to effectively improve the stage internal efficiency of turbine. Take high-pressure stage moving blade of a turbine as the research object, and adopt the k-ωSST model, the SIMPLEC algorithm to numerically simulate the formation and development process of leakage vortex between the tip clearance of the positive bending twisted blade and its effect on the secondary flow of cascade passage. Results show that relative to the conventional twisted blade, the scope of influence of leakage vortex which the steam flow formed near the suction surface of positive bending twisted blade and the disturbance to passage mainstream become smaller, and the increase of tip clearance has weakened the „C” type pressure gradient of suction surface of the positive bending twisted blade, increased the thickness of the boundary layer at both ends of blades and the loss of the blade end.

5

Preparation of CaCO3-SiO2 composite with core-shell structure and its application in silicone rubber

Cui Ch., Ding H., Cao L., Chen D.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 4

128--133

EN

A new CaCO3-SiO2 composite with core-shell structure was successfully prepared by mechano-chemistry method (MCM). SEM and FTIR indicated that SiO2 particles were homogeneously immobilized on the surface of CaCO3. The well dispersion of this CaCO3-SiO2 composite into silicone rubber can not only reduce the usage amount of SiO2, but also improve the mechanical properties of silicone rubber. By the calculation, the theoretical numbers of the SiO2 particles is about 10 times as large as that of CaCO3 particles in the CaCO3-SiO2 composite. Mixing CaCO3-SiO2 composite in silicone rubber can enhance the breaking strength of the silicone rubber about 18% as high as that when mixing the pure SiO2. And the elongation at break is about 14% less than that of adding the pure SiO2 sample.

6

Influence of Bi2O3 addition on structure and dielectric properties of Ag(Nb0.8Ta0.2)O3 ceramics

Cao L., Li L., Zhang P., Wang H.

Materials Science Poland

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2011

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Vol. 29, No. 1

1--8

EN

The structure and dielectric properties of perovskite Ag(Nb0.8Ta0.2)O3 ceramics were explored. A small amount of Bi2O3 was used to modify the dielectric properties of the ceramics. The addition of Bi2O3 led the ceramics to a high densification and optimal dielectric properties. With the addition of 4.5 wt% Bi2O3, the permittivity of Ag(Nb0.8Ta0.2)O3 ceramics increased from 470 to 733, the dielectric loss decreased from 62×10-4 to 6.7×10-4, and the temperature coefficient of capacitance, TCC, decreased from 2004 ppm/°C to -50 ppm/°C. The high permittivity obtained was due to the high densification and weak Ta-O or Nb-O bond strength in the oxygen octahedron that results from the addition of Bi2O3.

7

Synthesis of mesoporous silica by cationic surfactant templating in various inorganic acid sources

Xiang W. D., Yangy. Y. X., Zheng J. L., Cao L., Ding H. J., Liu X. N.

Materials Science Poland

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2010

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Vol. 28, No. 3

709--730

EN

Mesoporous silica materials with well-ordered hexagonal structure were synthesized under acidic conditions. The influences of crystallization conditions, aging conditions, acid sources HX and acid/tetraethyl orthosilicate ratio on the order degree and the morphology have been discussed. The increase of crystallization temperature or crystallization time was beneficial for the condensation of silica species, but had no effect on improving the order degree of mesoporous silica. The order degree of mesoporous materials using various acid sources HX under the same acid concentration swas as follows: HNO3HBrH2SO4HCl which differed from that in the Hofmeister series; the sulfate anions SO42- can play a supporting role on pore structure in the form of space occupation, leading to forming more ordered products than in HCl. Besides, the NO3- and Br- ions showed contrary effect on the growth of micelles, the bigger the pore wall thickness we obtained, the less HBr or the more HNO3 we used.