Wyniki wyszukiwania - Biblioteka Nauki

1

On the connective Cahn-Hilliard equation

100%

Liu C.

Bulletin of the Polish Academy of Sciences. Mathematics

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2005

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tom Vol. 53, no 3

299-314

EN

The author studies the convective Cahn-Hilliard equation. Some results on the existence of classical solutions and asymptotic behavior of solutions are established. The instability of the traveling waves is also discussed.

2

Deliberations about three-phase PLL technologies applied to a grid control of the renewable power system

63%

Liu L. , Liu C.

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3

Deliberations about three-phase PLL technologies applied to a grid control of the renewable power system

63%

Liu L. , Liu C.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2015

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tom Vol. 63, nr 1

261--267

EN

An efficient phase locked loop (PLL) method is very important to improve the grid-connected efficiency and the locked speed of frequency, phase, and voltage. However, most of literatures only introduce one PLL or one modified PLL method. There are many grid faults due to the grid connection to the renewable power generating system. A comparison and analysis is very important to select the most effective PLL technology for the grid-connected control of the renewable power system. Three PLL technologies are compared at different grid faults, such as single phase voltage drop, two phase voltage drop, frequency deviation, and voltage distortion. Simulation results indicated that different PLL methods have different locked performances at different grid faults.

4

New Method of Fabric Wrinkle Measurement Based on Image Processing

63%

Liu C. , Zhang C.

Fibres & Textiles in Eastern Europe

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2014

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tom Vol. 22, no. 1 (103)

51--55

EN

In this paper, a system of fabric wrinkle measurement was developed which consisted of a fabric wrinkle simulator, scanner and computer. The simulator generated “diamond” wrinkles just like those of the elbow and knee in actual wear. The images of wrinkled fabrics acquired by the scanner were processed with software developed in MATLAB and new characteristics of wrinkle severity (WS) and fabric unevenness (FU) in the warp and weft direction were proposed for the wrinkle characterisation. 15 different fabrics were used to compare the measurement results of the system with those of the AATCC 66-2008 test method. The results showed good agreement of the two methods and at a 45° wrinkle recovery angle, the correlation between the wrinkle recovery angle and WS or FU increased. Therefore it was advised that the wrinkle recovery angle of 45° be measured rather than averaging warp and weft wrinkle recovery angles only when using the AATCC 66-2008 test method. Compared with the AATCC 66-2008 test method, that in this paper can produce more “realistic” wrinkles and measure the wrinkling properties of fabrics in actual wear.

PL

Opracowana metoda polega na wykorzystaniu symulatora, skanera i komputera. Symulator generuje powstanie zmarszczek o kształcie odpowiadającym zmarszczkom na łokciach i kolanach powstałym podczas noszenia odzieży. Obrazy zmarszczek zidentyfikowane za pomocą skanera były przetwarzane za pomocą programu opracowanego w MATLAB. Do dalszej analizy zmarszczek wykorzystywano dwa parametry WS – intensywność zmarszczek i FU – nierównomierność materiału w kierunku wątku i osnowy. Dla porównań wykorzystano 15 różnych tkanin. Porównując wyniki uzyskane za pomocą analizowanego systemu z wynikami uzyskanymi z metody AATCC 66-2008 stwierdzono dobrą zgodność wyników uzyskanych z obydwu metod. Wyciągnięto praktyczne wnioski dotyczące stosowania obydwu metod przy ocenie zmarszczek ubrań po procesie noszenia.

5

Global attractor for the convective Cahn-Hilliard equation

63%

Zhao X. , Liu C.

Bulletin of the Polish Academy of Sciences. Mathematics

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2010

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tom Vol. 58, no 2

117-127

EN

This paper is concerned with the convective Cahn-Hilliard equation. We use a classical theorem on existence of a global attractor to derive that the convective Cahn-Hilliard equation possesses a global attractor on some subset of H2.

6

Weak solutions for a fourth order degenerate parabolic equation

63%

Liu C. , Guo J.

Bulletin of the Polish Academy of Sciences. Mathematics

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2006

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tom Vol. 54, no 1

27-39

EN

We consider an initial-boundary value problem for a fourth order degenerate parabolic equation. Under some assumptions on the initial value, we establish the existence of weak solutions by the discrete-time method. The asymptotic behavior and the finite speed of propagation of perturbations of solutions are also discussed.

7

The probabilistic solution of the Dirichlet problem for degenerate elliptic equations

63%

Liu C. , Morimoto H.

Bulletin of the Polish Academy of Sciences. Mathematics

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2006

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tom Vol. 54, no 2

163-174

EN

We study the Dirichlet problem for degenerate elliptic equations, and show that the probabilistic solution is a unique viscosity solution.

8

Beta-cryptoxanthin supplementation prevents cigarette smoke-induced lung inflammation, oxidative damage and squamous metaplasia in ferrets

51%

Liu C. , Bronson R. T. , Russell R. M. , Wang X. D.

Acta Biologica Cracoviensia. Series Botanica. Supplement

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2011

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tom 53

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nr 1

9

Comparison of the Structure and Properties of Wool and Cashmere Fibrrs under Potassium Permanganate Treatment

51%

Li L. , Qin C. , Liu C.

Fibres & Textiles in Eastern Europe

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2018

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tom Vol. 26, no. 4 (130)

29--33

EN

In this study, the weight loss and tensile property of wool fibers and cashmere fibers before and after various potassium permanganate solution treatment were investigated. The scale morphology andcrystallization index of the original and treated fibers were analysed with scanning electron microscopy and X-ray diffraction analysis. The experimental results showed that the weight loss of wool fibers is more than that of cashmere fibers under low potassium permanganate content treatment, but is less than that of cashmere fibers under high potassium permanganate content treatment. The force loss of cashmere fibers increased linearly with an increase in potassium permanganate content. The scales of cashmere fiber were damaged at a potassium permanganate content of 9%, but the scales of wool fiber were clear. The relative crystallisation index of treated wool is twice as that of treated cashmere at a potassium permanganate content of 9%.

PL

W pracy zbadano utratę masy i wytrzymałość na rozciąganie włókien wełnianych i kaszmirowych przed i po zastosowaniu różnych roztworów nadmanganianu potasu. Morfologię i wskaźnik krystalizacji pierwotnych i poddanych obróbce włókien analizowano za pomocą skaningowej mikroskopii elektronowej i dyfrakcji rentgenowskiej. Wyniki eksperymentalne wykazały, że ubytek masy włókien wełnianych jest większy, niż w przypadku włókien kaszmirowych po zastosowaniu obróbki nadmanganianem potasu. Utrata wytrzymałości włókien kaszmirowych wzrastała liniowo wraz ze wzrostem zawartości nadmanganianu potasu. Stwierdzono, że względny wskaźnik krystalizacji wełny poddanej obróbce jest dwukrotnie większy, niż w przypadku kaszmiru poddanego obróbce przy zawartości nadmanganianu potasu wynoszącej 9%.

10

Characterization and ecological significance of a seed bank from the Upper Pennsylvanian Wise Formation, southwest Virginia

51%

Yehnjong P. S. , Zavada M. S. , Liu C.

Acta Palaeobotanica

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2017

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tom 57

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nr 2

11

Experimental and numerical study on lateral stability of temporary structures

51%

Liu C. , He L. , Wu Z. , Yuan J.

Archives of Civil and Mechanical Engineering

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2018

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tom Vol. 18, no. 4

1478--1490

EN

This paper investigates the lateral performance of temporary structures, which consist of slender members and corresponding joints, under both vertical and horizontal loads. The ultimate bearing capacity, failure modes and the strain distribution of members are illustrated. Experimental results indicate that the lateral stability of the temporary structures is weaker than the vertical stability. Diagonal bracings are the main load-bearing members which resist horizontal loads while the horizontal bars are used to keep stress low. Based on the joint mechanical parameters and the probabilistic models of initial geometric imperfection, the stochastic finite element models (SFEMs) using the Monte Carlo method have been established. The models can consider the semi-rigid performances of joints and initial geometric imperfection. The numerical results demonstrate consistency with structural tests data. Moreover, the influences of structural layers and spans are analysed based on the SFEM. Multiple factors, including spans, layers and upper vertical loads, should be considered when the lateral capacity of temporary structures is calculated. A rapid prediction formula of the lateral stability of temporary structure has been obtained.

12

Beta-cryptoxanthin inhibits lung tumor by suppressing alfa 7 nicotinic receptor expression and AKT activation in A/J mouse model

51%

Iskandar A. , Liu C. , Ernst H. , Wang X. D.

Acta Biologica Cracoviensia. Series Botanica. Supplement

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2011

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tom 53

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nr 1

13

High resolution and analytical electron microscopy of ZnO layers doped with magnetic ions for spintronic applications

51%

Abouzaid M. , Ruterana P. , Liu C. , Morkoc H.

Optica Applicata

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2006

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tom Vol. 36, nr 2-3

311-320

EN

We have investigated the effect of temperature on the crystalline quality of (Zn, Mn)O thin films prepared by rf magnetron sputtering using c-plane sapphire substrates. The layers comprised an Mn doped part towards the surface on top of about a 150 nm pure ZnO layer. They exhibit a columnar structure depending on the deposition temperature; the adjacent domains are rotated from one another by 90°, putting [1010] and [1120] directions face to face. At high Mn concentration this columnar structure is blurred by the formation of Mn rich precipitates for which we report on the structure, composition and crystallographic relationships with the surrounding matrix.

14

Cadmium-induced alterations in morpho-physiology of two peanut cultivars differing in cadmium accumulation

51%

Zhang Z. , Liu C. , Wang X. , Shi G.

Acta Physiologiae Plantarum

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2013

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tom 35

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nr 07

EN

This study examines differences in the morphophysiological responses of low- and high-cadmium (Cd) accumulating peanut (Arachis hypogaea L.) cultivars to Cd stress. The biomass, Cd accumulation, leaf gas exchange, root morphology, root respiration, and hydraulic conductivity of Qishan 208 (low-Cd accumulator) and Haihua 1 (high-Cd accumulator) were determined via a hydroponic experiment. Exposure of peanut plants to 2 and 20 μM Cd considerably decreased their shoot biomass, net photosynthetic rate, transpiration rate, stomatal conductance, total root length, number of root tips, root respiration, and hydraulic conductivity. The root biomass, root surface area, and average diameter were unaffected by Cd exposure. The two cultivars differed in Cd accumulation and morphophysiological responses to Cd stress. Qishan 208 accumulated less Cd in plant tissues but was more sensitive to Cd stress than Haihua 1. The total root length, surface area, average diameter, number of root tips, and root respiration rate of Haihua 1 were significantly higher than those of Qishan 208. The well-developed root system and higher root respiration of Haihua 1 may be responsible for its high Cd accumulation capacity.

15

Efficient Computation of Palindromes in Sequences with Uncertainties

51%

Alzamel M. , Gao J. , Iliopoulos C. S. , Liu C.

Fundamenta Informaticae

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2018

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tom Vol. 163, nr 3

253--266

EN

In this work, we consider a special type of uncertain sequence called weighted string. In a weighted string every position contains a subset of the alphabet and every letter of the alphabet is associated with a probability of occurrence such that the sum of probabilities at each position equals 1. Usually a cumulative weight threshold 1/z is specified, and one considers only strings that match the weighted string with probability at least 1/z. We provide an O(nz)-time and O(nz)-space off-line algorithm, where n is the length of the weighted string and 1/z is the given threshold, to compute a smallest maximal palindromic factorization of a weighted string. This factorization has applications in hairpin structure prediction in a set of closely-related DNA or RNA sequences. Along the way, we provide an O(nz)-time and O(nz)-space off-line algorithm to compute maximal palindromes in weighted strings. Finally, we provide an experiment of our proposed algorithm.

16

Investigation and optimization of use of anionic collectors in direct flotation of bauxite ores

51%

Liu C. , Feng A. , Guo Z.

Physicochemical Problems of Mineral Processing

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2016

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tom Vol. 52, iss. 2

932--942

EN

Bauxite is the main raw material for the alumina industry. Direct flotation is the most widely used method for bauxite beneficiation. In this study, a large number of direct flotation tests were carried out using several anionic reagents. The testing concluded that vegetable oil acid (VOA), naphthenic acid (NA) and lauryl polyoxyethylene phosphate (AEP12) were the three outstanding collectors for bauxite direct flotation. ZMC collector was mixed and prepared using VOA, NA and AEP12, in which the mass ratio of VOA, NA and AEP12 was 1:1:0.5. When processing the bauxite ores of the mass ratio of Al2O3 to SiO2 (A/S) = 4.99, the A/S of the final concentrate was 7.08 and the recovery of Al2O3 was 90.22%. When processing ores of A/S = 4.5, the A/S of the final concentrate was 7.04 and the recovery of Al2O3 was 92.16%. Thus, it can be seen that properties and behaviors of the ZMC reagent were remarkable and met the demands of the “Lime-Bayer Process”.

17

Pre-concentration of vanadium-bearing mica from stone coal by roasting-flotation

51%

Tang J. , Zhang Y. , Bao S. , Liu C.

Physicochemical Problems of Mineral Processing

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2017

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tom Vol. 53, iss. 1

402--412

EN

In China, stone coal is an important source of vanadium. The use of roasting–floatation for the pre-concentration of vanadium bearing mica from vanadium bearing stone coal was investigated based on its mineralogical characteristics. The results showed that the vanadium occurred in mica minerals and the main gangue minerals were coal, calcite, and quartz. The pre-concentration process comprises three key steps: roasting, desliming, and flotation. The coal was completely removed by roasting at 700 °C for an hour. Slime was concentrated and the subsequent flotation pulp was improved by desliming. Calcite was removed by reverse flotation and mica was concentrated by positive floatation. During the process, the grade of V2O5 was increased from 0.71% to 1.14%, and 46.18% of the tailings were rejected. The leaching rate of vanadium was increased from 30.49% of raw ore to 69.15% of the concentrate which was an increase of about 40% at the same leaching process. This technique may promote the efficient utilization of stone coal resources.

18

Morphometric indices in an annual fishthe redtail notho, Nothobranchius guentheri (Actinopterygii: Cyprinodontiformes: Nothobranchiidae): Influence of age and gender

51%

Pawar R. , Zhang S. , Liu C.

Acta Ichthyologica et Piscatoria

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2012

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tom 42

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nr 4

EN

Background. Though fishes grow indeterminately, very little is known of the effects of age on the morphometric indices (length, weight, and condition) in fishes as it is often difficult to cover the entire lifespan of a species in laboratory or nature. The presently reported study was thus conducted to elucidate the effects of age (and sex) on the growth indices using the annual fish and a laboratory model of aging. Materials and Methods. Experimental fish—the redtail notho, Nothobranchius guentheri (Pfeffer, 1893), were obtained by hatching the diapause eggs of the same parental lineage and reared over their entire lifespan. Length–weight measurements were recorded from 3–12 months and various indices (length–weight relation, Fulton’s condition factor, and relative condition factor) were computed and compared statistically. Results. Mean lengths, weights, length–weight relations (LWRs), Fulton’s condition factor (K) and relative condition factor (Kn) varied significantly leading to differential indices based on age and sex. Age influenced all indices positively, which is indicative of the indeterminate growth typical of fishes. Conclusion. Age was not seen to suppress the growth indices in the annual fish, which is suggestive of a healthy and delayed senescence in the annual fish N. guentheri. Whether other short- and long-lived finfish follow the same pattern needs further investigation.

19

2D Structural Acoustic Analysis Using the FEM/FMBEM with Different Coupled Element Types

51%

Chen L. , Zhao W. , Liu C. , Chen H.

Archives of Acoustics

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2017

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tom Vol. 42, No. 1

37--48

EN

A FEM-BEM coupling approach is used for acoustic fluid-structure interaction analysis. The FEM is used to model the structure and the BEM is used to model the exterior acoustic domain. The aim of this work is to improve the computational efficiency and accuracy of the conventional FEM-BEM coupling approach. The fast multipole method (FMM) is applied to accelerating the matrix-vector products in BEM. The Burton-Miller formulation is used to overcome the fictitious eigen-frequency problem when using a single Helmholtz boundary integral equation for exterior acoustic problems. The continuous higher order boundary elements and discontinuous higher order boundary elements for 2D problem are developed in this work to achieve higher accuracy in the coupling analysis. The performance for coupled element types is compared via a simple example with analytical solution, and the optimal element type is obtained. Numerical examples are presented to show the relative errors of different coupled element types.

20

A Iontophoretic delivery of transdermal patches containing ropivacaine: sustaining the anesthetic effect in children

51%

Yu T. , Zhang S. , Cao X. , Liu C.

Acta Biochimica Polonica

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2019

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tom 66

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nr 2