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31.
Pei‐Hsuan Wang Ming‐Shou Ho Sheng‐Hsiung Yang Kuei‐Bai Chen Chain‐Shu Hsu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):516-524
Three polyfluorene derivatives which have oxetane‐containing phenyl group at C‐9 position were synthesized via the palladium‐catalyzed Suzuki‐coupling reaction. The synthesized polymers PFB, PFG, and PFR emit blue, green, and red light, respectively. A double‐layer device with the configuration of ITO/PEDOT/polymer/Ca/Al using PFB as the active layer showed a threshold voltage of 5 V, a maximum brightness of 2030 cd/m2, and a maximum current efficiency of 0.35 cd/A. Using PFG as the active layer, the device exhibited a threshold voltage of 6 V, a maximum brightness of 6447 cd/m2, and a maximum current efficiency of 1.27 cd/A. Using PFR as the active layer, the device showed a threshold voltage of 4 V, a maximum brightness of 2135 cd/m2, and a maximum current efficiency of 0.16 cd/A. Better electroluminescent performance was also found based on different design of device structures. Due to photo‐crosslinking property of oxetane groups, the UV‐exposed thin films are insoluble in common organic solvents. A device comprised of blue, green, and red‐emissive pixels was successfully fabricated by spin‐coating and photo‐lithographic processes. In addition, a white light‐emitting device with CIE coordinate of (0.34, 0.33) was achieved by blending PFR into a host material PFB as the active layer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 516–524, 2010 相似文献
32.
Yu‐Liang Yang Dr. Wen‐Ying Liao Wan‐Yun Liu Chih‐Chuang Liaw Dr. Chia‐Ning Shen Dr. Zih‐You Huang Shih‐Hsiung Wu Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(43):11573-11580
Six photosensitive polyketides, malbranpyrroles A–F, were discovered from the thermophilic fungus Malbranchea sulfurea by using intact‐cell desorption/ionization on silicon mass (ICD‐MS) and LC‐SPE‐NMR. These two strategies facilitate the searching and structural determination of unstable natural products. The ICD‐MS indicated that only brown hyphae of M. sulfurea can produce malbranpyrroles. The biosynthetic pathway of malbranpyrroles was evidenced by 13C isotope precursors and amino acid feeding experiments. The cytotoxicity data revealed that the conformation of the conjugated system in malbranpyrroles does not affect cytotoxic potency against cancer cell lines. In addition, the chlorine atom was shown to be the pharmacophore for cytotoxicity. 相似文献
33.
The purpose of this paper is to introduce a new class of almost complex structures J on a Riemannian manifold M by using a certain identity for the relationship between the tensor F
i
j
of J and the Riemann curvature tensor R
hijk
of M. This class contains the Kählerian structures, and its relationship with some known classes of almost Hermitian structures defined by similar identities is discussed. For convenience we call each structure of this new class an almost C-structure, and a manifold with an almost C-structure an almost C-manifold. We obtain an analogue of F. Schur's theorem concerning the holomorphic sectional curvature of an almost Hermitian C-manifold, and some sufficient conditions for an almost Hermitian C-manifold to be Kählerian. We show that these results are also true for a manifold with a complex structure. 相似文献
34.
Sheng Hsiung Lin 《Applied Scientific Research》1974,30(2):113-126
The purpose of this paper is to analyze the homogeneous consecutive chemical reactions carried out in an annular reactor with non-Newtonian laminar flow. The fluids are assumed to be characterized by a Ostwald-de Waele (powerlaw) model and the reaction kinetics is considered of general order. Effects of flow pseudoplasticity, dimensionless reaction rate constants, order of reaction kinetics and ratio of inner to outer radii of reactor on the reactor performances are examined in detail.Nomenclature
c
A
concentration of reactant A, g.mole/cm3
-
c
B
concentration of reactant B, g.mole/cm3
-
c
A0
inlet concentration of reactant A, g.mole/cm3
-
C
1
dimensionless concentration of A, c
A/c
A0
-
C
2
dimensionless concentration of B, c
B/c
A0
- C
1
dimensionless bulk concentration of A
- C
2
dimensionless bulk concentration of B
-
D
A
molecular diffusivity of A, cm2/sec
-
D
B
molecular diffusivity of B, cm2/sec
-
k
A
first reaction rate constant, (g.mole/cm3)1–m
/sec
-
k
B
second reaction rate constant, (g.mole/cm3)1–n
/sec
-
K
1
dimensionless first reaction rate constant, k
A
r
0
2
c
A0
m–1
/D
A
-
K
2
dimensionless second reaction rate constant, k
B
r
0
2
c
A0
n–1
/D
B
-
K
apparent viscosity, dyne(sec)
m
/cm2
-
m
order of reaction kinetics
-
n
order of reaction kinetics
-
P
pressure, dyne/cm2
-
r
radial coordinate, cm
-
r
i
radius of inner tube, cm
-
r
max
radius at maximum velocity, cm
-
r
o
radius of outer tube, cm
-
R
dimensionless radial coordinate, r/r
o
-
s
reciprocal of rheological parameter for power-law model
-
u
local velocity, cm/sec
-
u
max
maximum velocity, cm/sec
- u
bulk velocity, cm/sec
-
U
dimensionless velocity, u/u
-
z
axial coordinate, cm
-
Z
dimensionless axial coordinate, zD
A/r
0
2
/u
-
ratio of molecular diffusivity, D
B/D
A
-
ratio of inner to outer radius of reactor, r
i/r
o
-
ratio of radius at maximum velocity to outer radius, r
max/r
o 相似文献
35.
Chun‐Hsiung Chien Yu‐Hsu Chang Chih‐Pin Tsai Chih‐Wei Peng Lung‐Shen Wang Pei‐Sun Sheng Chi‐Young Lee Hsin‐Tien Chiu 《中国化学会会志》2006,53(2):287-292
Black solid precursors obtained from reactions between MCl5 (M = Nb, Ta) and alkyllithiums, n‐butyllithium (nBuLi) and ethyllithium (EtLi), in tetrahydrofuran (THF) were heat treated under vacuum at 673–973 K to form nano‐sized particles (20–100 nm in diameter) of lithium niobate (LiNbO3) and lithium tantalate (LiTaO3). Stoichiometry of the reactants is critical and affects the phases of the products. Based on the volatile byproducts detected, a reaction pathway involving the activation of THF by alkyllithiums is proposed to be important for the formation of LiNbO3 and LiTaO3 precursors. 相似文献
36.
A simple electrode is described for the assay of methylamine in the concentration range 10-5–10-2 M. The electrode is based on the air-gap sensor principle. In the range of linear response, the relative standard deviation is about 1.4 % when the measurement time is 24 min, and about 5 % when the equilibration time is 12 min. Some interference is noted from dimethylamine and ammonium chloride. 相似文献
37.
Probability Theory and Related Fields - A renewal theorem of the elementary type for some stopping times which arise from some statistical estimation problems has been established. It is applied to... 相似文献
38.
Optical and Quantum Electronics - 相似文献
39.
A specific enzyme electrode procedure is described for the rapid assay of L-phenyl- alanine. The enzyme L-phenylalanine ammonia lyase is used, which cleaves L-phenyl-alanine to ammonia. The ammonia liberated is measured with an air-gap electrode. The procedure is specific; L-tyrosine and other amino acids do not interfere, nor do Na+ or K+ ions. As little as 5 · 10-5 M L-phenylalanine can be determined. 相似文献
40.
A single chiral structure is shown to underly several three-dimensional field equations of physics, e.g., the ferromagnet, the stationary axi-symmetric gravitational problem, and the vacuum SU(2) gauge field in the Coulomb gauge. This connection invites cross-fertilization of exact solutions. As illustrations, exact finite energy solutions are obtained for the ferromagnet via the corresponding Weyl, Kerr, and Tominatsu-Sato solutions of Einstein's gravitational equations. Comments are made on the “local gauge invariance” of the ferromagnet and the gravitational field. 相似文献