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Wyszukujesz frazę "Chen, R." wg kryterium: Autor


Tytuł:
Crystal Structure of K$\text{}_{3}$Na(SeO$\text{}_{4}$)$\text{}_{2}$ at 340 K
Autorzy:
Fukami, T.
Chen, R. H.
Powiązania:
https://bibliotekanauki.pl/articles/1993089.pdf
Data publikacji:
1998-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Fn
64.60.Fr
Opis:
The crystal structure of tripotassium sodium diselenate, K$\text{}_{3}$Na(SeO$\text{}_{4}$)$\text{}_{2}$, at 340 K is studied by single-crystal X-ray diffraction. The space group symmetry (trigonal P3̅) and structure parameters are determined. It is found that there exists the difference of the direction and the magnitude of the atomic displacement at the two phase transitions of 346 K and 334 K.
Źródło:
Acta Physica Polonica A; 1998, 94, 5-6; 795-801
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Phase Transition and Crystal Structure for (ND$\text{}_{4}$)$\text{}_{4}$D$\text{}_{2}$(SeO$\text{}_{4}$)$\text{}_{3}$ at Low Temperature
Autorzy:
Fukami, T.
Chen, R. H.
Powiązania:
https://bibliotekanauki.pl/articles/2027434.pdf
Data publikacji:
2001-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Fn
64.60.Fr
Opis:
Differential scanning calorimetry and X-ray diffraction measurements were performed on a deuterated tetraammonium dihydrogen triselenate (ND$\text{}_{4}$)$\text{}_{4}$D$\text{}_{2}$(SeO$\text{}_{4}$)$\text{}_{3}$ crystal at low temperatures. A structural phase transition is found at 182.0(3) K. The space group symmetry (triclinic P1) and the structure parameters are determined at 145 K in the low-temperature phase. The isotope effect for an asymmetric O-H-O hydrogen bond by the substitution of deuterium is discussed.
Źródło:
Acta Physica Polonica A; 2001, 100, 1; 53-65
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Study of (NH$\text{}_{4}$)$\text{}_{4}$H$\text{}_{2}$(SeO$\text{}_{4}$)$\text{}_{3}$ in the Low-Temperature Phase
Autorzy:
Fukami, T.
Higa, N.
Chen, R. H.
Powiązania:
https://bibliotekanauki.pl/articles/2013261.pdf
Data publikacji:
2000-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Fn
64.60.Fr
Opis:
The crystal structure of tetraammonium dihydrogen triselenate, (NH$\text{}_{4}$)$\text{}_{4}$H$\text{}_{2}$(SeO$\text{}_{4}$)$\text{}_{3}$, in the low-temperature phase at 141 K is studied by X-ray diffraction. The space group symmetry (triclinic P1) and the structure parameters are determined. By the shift of the Se atom from the center of the SeO$\text{}_{4}$ tetrahedron, it is suggested that the (NH$\text{}_{4}$)$\text{}_{4}$H$\text{}_{2}$ (SeO$\text{}_{4}$)$\text{}_{3}$ crystal in the low-temperature phase is ferroelectric with the electric dipole moment along the c-axis. The rotation of the SeO$\text{}_{4}$ tetrahedron suggested by electron paramagnetic resonance measurements is discussed.
Źródło:
Acta Physica Polonica A; 2000, 97, 4; 663-670
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Iterative estimators of parameters in linear models with partially variant coefficients
Autorzy:
Hu, S.
Meinke, K.
Chen, R.
Huajiang, O.
Powiązania:
https://bibliotekanauki.pl/articles/929607.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model liniowy
estymacja parametrów
algorytm iteracyjny
współczynnik zmienności
linear model
parameter estimation
iterative algorithms
variant coefficients
Opis:
A new kind of linear model with partially variant coefficients is proposed and a series of iterative algorithms are introduced and verified. The new generalized linear model includes the ordinary linear regression model as a special case. The iterative algorithms efficiently overcome some difficulties in computation with multidimensional inputs and incessantly appending parameters. An important application is described at the end of this article, which shows that this new model is reasonable and applicable in practical fields.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2007, 17, 2; 179-187
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of scheelite from calcite using sodium polyacrylate as depressant
Autorzy:
Zhang, Y.
Chen, R.
Li, Y.
Wang, Y.
Luo, X.
Powiązania:
https://bibliotekanauki.pl/articles/110896.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
scheelite
calcite
flotation
sodium polyacrylate
selective depression
Opis:
The depressing properties of sodium polyacrylate (PA-Na) for calcite from scheelite were studied by microflotation experiments, zeta potentials, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculation. Flotation results revealed that the selective depression effect of PA-Na was better than that of sodium silicate (Na2SiO3), and PA-Na can depress calcite more effectively than scheelite. The flotation recovery of scheelite and calcite kept at about 75% and 15% respectively at the pulp pH 9.3~9.6 and PA-Na concentration from 37.5 mg/dm3 to 50 mg/dm3. The zeta potentials of the minerals were significantly altered and the zeta potential of calcite became more negative than scheelite. XPS analysis deduced the occurrence of chemisorption between PA-Na and mineral surfaces, and the chemisorption of PA-Na on calcite was stronger than on scheelite. The results from DFT calculation demonstrated that the absolute value of the adsorption energy in the presence of PA-Na on the surface of calcite {104} was larger than on the surface of scheelite {111}. With the combination of the analysis, it could be concluded that calcite was more easily depressed than scheelite, and this finding remarkably matched with the microflotation experimental results. Furthermore, by using PA-Na as depressant, the flotation separation of scheelite from calcite can be achieved by controlling the flotation pH and PA-Na dosage.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 505-516
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image compression-encryption algorithm combining compressive sensing with log operation
Autorzy:
Chen, R.-L.
Zhou, Y.
Luo, M.
Zhang, A.-D.
Gong, L.-H.
Powiązania:
https://bibliotekanauki.pl/articles/174009.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
image compression
compressive sensing
log operation
Opis:
Based on compressive sensing and log operation, a new image compression-encryption algorithm is proposed, which accomplishes encryption and compression simultaneously. The proposed image compression-encryption algorithm takes advantage of not only the physical realizability of partial Hadamard matrix, but also the resistance of the chosen-plaintext attack since all the elements in the partial Hadamard matrix are 1, –1 or log 1 = 0. The proposed algorithm is sensitive to the key and it can resist various common attacks. The simulation results verify the validity and reliability of the proposed image compression-encryption algorithm.
Źródło:
Optica Applicata; 2018, 48, 4; 563-573
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In vitro cloning potential and phytochemical evaluations of aneuploid individuals produced from reciprocal crosses between diploid and triploid in Echinacea purpurea L.
Autorzy:
Li, Q.
Jiang, W.
Ren, Y.
Chen, R.
Li, X.
Yang, Y.
Wu, H.
Powiązania:
https://bibliotekanauki.pl/articles/58769.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
Aneuploidy often presents large variations in morphology, physiology, biochemistry, and genetics owing to karyotypic imbalance. This study aimed to evaluate the efficacy of aneuploid breeding in Echinacea purpurea L, an important medicinal plant. Reciprocal crosses between diploid and triploid plants were performed to generate aneuploid plants. Cross with triploid as female parent resulted in increased production of aneuploid individuals (19 of 23; 82.61%), while using diploid as female parent yielded much higher percentage of diploid progenies (130 of 133; 97.74%). Each aneuploid had particular karyotypic characteristics compared to the parents. The proportions of median, submedian, and subterminal centromere location chromosomes in gross chromosomes among aneuploids and two parents showed large variations. Although aneuploids had relatively lower adventitious bud regeneration rates than their parents, almost half of them looked morphologically normal, with high survival rates when transplanted to ex vitro conditions. Among the bioactive compounds assessed, cichoric acid and chlorogenic acid contents were extremely encouraging. Most aneuploids had higher cichoric acid and chlorogenic acid contents than their parents. For example, A2 had the highest cichoric acid content of 21.98 mg/g dry weight, more than twice the values of diploid and triploid. Meanwhile, A21 had the highest chlorogenic acid content of 1.84 mg/g, approximately five times more than the parental values. Eleven superior aneuploid lines were successfully screened as breeding candidates. The present findings indicated E. purpurea is highly tolerant of karyotypic imbalance and aneuploid plants could serve as prospective breeding resources in E. purpurea.
Źródło:
Acta Societatis Botanicorum Poloniae; 2017, 86, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Requirement for and Use of Coated P92 Steel for Enhanced Structural Integrity at High Temperature
Autorzy:
Hoey, T.
Chen, R.
McCartney, D.
Sun, W.
Mansfield, J.
Barnard, P.
Foster, J.
Powiązania:
https://bibliotekanauki.pl/articles/1402066.pdf
Data publikacji:
2015-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.15.Pq
68.37.-d
61.05.-a
64.75.-g
Opis:
To achieve climate change targets and to improve the efficiency of fossil fuel power plant the temperature and pressure of operation must be increased. With steam temperatures predicted to rise by 50-100 K in the next 30 years, this presents a number of material challenges, not least for the ferritic steels used for steam pipework. Currently the best in class ferritic steel for power plant steam pipework is P92, a 9-12% Cr advanced martensitic steel that was developed for its superior high temperature creep resistance. This paper will give a brief overview of P92 microstructure, composition and metallurgy and identify experimentally and computationally some key features of the material. As well as failure by creep, P92 at high temperature also suffers from steam oxidation damage. Recent literature suggests that coatings applied to P92 are a very promising solution. A short review of previous work on steam oxidation resistant coatings for P92 is included. A novel Co-Cr-C coating that has not previously been explored for this application is described. Experimental and computational characterisation is included.
Źródło:
Acta Physica Polonica A; 2015, 128, 4; 514-519
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-Pressure Studies of Semiconductors in the Far-Infrared: Donor States in Quasi-2D
Autorzy:
Weinstein, B. A.
Tischler, J. G.
Chen, R. J.
Nickel, H. A.
McCombe, B. D.
Dzyubenko, A. B.
Sivachenko, A.
Powiązania:
https://bibliotekanauki.pl/articles/2014129.pdf
Data publikacji:
2000-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.66.Fd
73.20.Dx
73.20.Hb
Opis:
We review recent experimental advances by the Buffalo group in performing far-infrared magnetospectroscopy under fine tuning of applied high hydrostatic pressure. Experiments are reported for the effects of pressure on Si donors in modulation doped GaAs/AlGaAs quantum wells. We clearly observe pressure-mediated competition between free (i.e., Landau level) and bound electron states - the latter arising from both neutral (D$\text{}^{0}$) and charged (D$\text{}^{-}$) donor species. With increasing pressure, there is a progression of the observed spectra from being dominated by cyclotron resonance and the D$\text{}^{-}$ singlet (or singlet-like bound magnetoplasmon) transitions, to showing the D$\text{}^{0}$ 1s → 2p$\text{}^{+}$ line. The main reason for this evolution is the decrease in electrons due to the crossover of the Si levels associated with the Γ (well) and X (barrier) conduction minima. Indeed, for pressures above 30 kbar the Γ(well)-X(barrier) crossover quenches all the transitions. However, we find strong evidence that electrons are independently lost to a trap, which becomes active several kbar below this crossing. A possible candidate for this trap is residual Se impurities in the barriers. We present the results of detailed numerical calculation which are found to agree very well with the measured field dependencies of the cyclotron resonance, D$\text{}^{0}$ and D$\text{}^{-}$ transition energies. In the sample with the highest doping, a new transition is observed for fields and pressures above 7.5 T and 5 kbar. Reasons for this apparent anomaly are discussed.
Źródło:
Acta Physica Polonica A; 2000, 98, 3; 241-257
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isolation and sequence analysis of the complete VP2 gene of canine parvovirus from Chinese domestic pets and determination of the pathogenesis of these circulating strains in beagles
Autorzy:
Chen, M.R.
Guo, X.Y.
Wang, Z.Y.
Jiang, Y.T.
Yuan, W.F.
Xin, T.
Hou, S.H.
Song, T.Q.
Lin, W.D.
Zhu, H.F.
Jia, H.
Powiązania:
https://bibliotekanauki.pl/articles/2087542.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
canine parvovirus
molecular epidemiology
phylogenetic analysis
pathogenesis
Źródło:
Polish Journal of Veterinary Sciences; 2019, 2; 287-296
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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