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排序方式: 共有143条查询结果,搜索用时 125 毫秒
101.
Triphenylamine Groups Improve Blocking Behavior of Phenoxazine Dyes in Cobalt‐Electrolyte‐Based Dye‐Sensitized Solar Cells 下载免费PDF全文
Dr. Yan Hao Dr. Haining Tian Dr. Jiayan Cong Wenxing Yang Ilkay Bora Prof. Licheng Sun Dr. Gerrit Boschloo Prof. Anders Hagfeldt 《Chemphyschem》2014,15(16):3476-3483
Novel phenoxazine dyes are successfully introduced as sensitizers into dye‐sensitized solar cells (DSCs) with cobalt‐based electrolyte. In sensitizers with triphenylamine (TPA) groups recombination from electrons in the TiO2 conduction band to the cobalt(III) species is suppressed. The effect of the steric properties of the phenoxazine sensitizers on the overall device performance and on recombination and regeneration processes is compared. Optimized DSCs sensitized with IB2 having two TPA groups in combination with tris(2,2′‐bipyridyl) cobalt(II/III) yield efficiencies of 6.3 %, similar to that of IB3 , which is equipped with mutiple alkoxy groups. TH310 with only one TPA group gives lower efficiency and open circuit voltage, while IB1 without TPA groups performs even worse. These results demonstrate that both TPA groups on the IB2 are needed for an efficient blocking effect. These results reveal a possible new role for TPA units in DSC sensitizer design. 相似文献
102.
Fluorinated alkoxytrimethylsilanes (RfCH2OSiMe3), potential candidates for the third-generation cleaning agents, were synthesized in high yields over 95% from the reaction of chlorotrimethylsilane and fluorinated alcohol (RfCH2OH) in the presence of 1-methylimidazole. Elemental and 1H NMR spectroscopic analysis showed that the reaction proceeds through the formation of an intermediate, 3-methyl-1-trimethylsilylimidazolium chloride. 相似文献
103.
Platinum(IV) halides formed complexes of the type PtL2X4 [L=1-vinyl imidazole (1,-VIm), 1-methylimidazole (1-MeIm), 1,2-dimethylimidazole (1,2-Me2Im), 1-vinyl-2-methylimidazole (1-V-2-MeIm), 2-methylimidazole (2-MeIm), 2-ethylimidazole (2-EtIm), 2-isopropylimidazole (2-i-PrIm), and 4-methylimidazole (4-MeIm); X=Cl, Br] in neutral aqueous solution. The 1-n-butylimidazole (1-n-BuIm) ligand yielded only (LH)2PtX6 compound in the same medium. The compounds were characterised by elemental analyses, IR, UV-VIS and 1HNMR spectra. 相似文献
104.
A highly efficient heterogeneous montmorillonite K‐10‐supported palladium catalyst for Suzuki–Miyaura cross‐coupling reaction in aqueous medium 下载免费PDF全文
A heterogeneous montmorillonite K‐10‐supported palladium triphenylphosphine catalyst is reported for the Suzuki–Miyaura cross‐coupling reaction at room temperature. A library of electronically diverse aryl bromides and arylboronic acids underwent the cross‐coupling reaction at very good rates in aqueous solvent. The reusability of the catalyst was also examined and it was found to be effective up to three catalytic cycles. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
105.
106.
Bora Çekyay 《European Journal of Operational Research》2012,219(1):123-133
We consider the maintenance of a mission-based system that is designed to perform missions consisting of a random sequence of phases or stages with random durations. A finite state Markov process describes the mission process. The age or deterioration process of the system is described by another finite state Markov process whose generator depends on the phases of the mission. We discuss optimal repair and optimal replacement problems, and characterize the optimal policies under some monotonicity assumptions. We also provide numerical illustrations to demonstrate the structure of the optimal policies. 相似文献
107.
Naresh Kasoju Debajeet K. Bora Ramesh R. Bhonde Utpal Bora 《Journal of nanoparticle research》2010,12(3):801-810
We report the synthesis of novel biodegradable nanoparticles (NPs) which can kill the cancer cells without any additional
drug loading. The NP was a self-assembled form of a phthalimide based conjugate, in which the phthalimide moiety was responsible
for the anticancer activity. We describe the synthesis of a novel 2-(N-phthalimido) ethyl palmitate (PHEP-Pal) conjugate and
subsequent preparation of NPs by a simple self assembly process. The successful synthesis of conjugate was confirmed by various
characterization studies including nuclear magnetic resonance spectroscope, Fourier transform infrared spectroscope, TOF-liquid
chromatography mass spectroscope, differential scanning calorimetry, and X-ray diffraction unit. The synthesis, shape, size,
and size distribution of PHEP-Pal NPs were determined by transmission electron microscope, atomic force microscope, and dynamic
light scattering technique. Finally, cell culture studies using A549 and HeLa cells were done to evaluate the anticancer effect
of PHEP-Pal NPs, which demonstrated the potency of these NPs for use in cancer chemotherapy. 相似文献
108.
A 3.7 GHz system, which is meant for LHCD experiments on ADITYA tokamak, is used for producing ECR discharge. The ECR discharge
is produced by setting the appropriate resonance magnetic field of 0.13 T, with hydrogen at a fill pressure of about 5 × 10−5 Torr. The RF power, up to 10 kW (of which ∼50% is reflected back), with a typical pulse length of 50 ms, is injected into
the vacuum chamber of the ADITYA tokamak by a LHCD grill antenna and is used for plasma formation. The average coupled RF
power density (the RF power/a typical volume of the plasma) is estimated to be ∼5 kW/m3. When the ECR appears inside the tokamak chamber for the given pumping frequency (f = 3.7 GHz) a plasma with a density (n
e) ∼ 4 × 1016 m−3 and electron temperature ∼8 eV is produced. The density and temperature during the RF pulse are measured by sets of Langmuir
probes, located toroidally, on either side of the antenna. Hα signals are also monitored to detect ionization. An estimate of density and temperature based on simple theoretical calculation
agrees well with our experimental measurements. The plasma produced by the above mechanism is further used to characterize
the ECR-assisted low voltage Ohmic start-up discharges. During this part of the experiments, Ohmic plasma is formed using
capacitor banks. The plasma loop voltage is gradually decreased, till the discharge ceases to form. The same is repeated in
the presence of ECR-formed plasma (RF pre-ionization), formed 10 ms prior to the loop voltage. We have observed that (with
LHCD-induced) ECR-assisted Ohmic start-up discharges is reliably and repeatedly obtained with reduced loop voltage requirement
and breakdown time decreases substantially. The current ramp-up rates also decrease with reduced loop voltage operation. These
studies established that ECR plasma formed with LHCD system exhibits similar characteristics as reported earlier by dedicated
ECR systems. This experiment also addresses the issue of whether ECR plasma formed with grill antenna exhibits similar behavior
as that formed by single waveguide ECR antenna. Our experimental observations suggest that the characteristics of (LHCD system-induced)
ECR-assisted Ohmic start-up discharges show similar properties, reported earlier with normal ECR-assisted Ohmic start-up discharges
and hence LHCD system may be used as ECR system at reduced toroidal magnetic field for other applications like wall conditioning.
相似文献
109.
Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases
— hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02
GHz in TE10 mode and launched radially to have extra-ordinary (X) wave in plasma. The axial magnetic field required for ECR in the system
is such that the fundamental ECR surface (B = 875.0 G) resides at the geometrical centre of the plasma system. ECR breakdown parameters such as plasma delay time and
plasma decay time from plasma density measurements are carried out at the centre using a Langmuir probe. The operating parameters
such as working gas pressure (1 × 10−5−1× 10−2 mbar) and input microwave power (160–800 W) are varied and the corresponding effect on the breakdown parameters is studied.
The experimental results obtained are presented in this paper.
相似文献
110.
A magnetized, low-β plasma in pure toroidal configuration is formed and extensively studied with ion mass as control parameter. Xenon, krypton
and argon plasmas are formed at a fixed toroidal magnetic field of 0.024 T, with a peak density of ∼1011 cm−3, ∼4 × 1010 cm −3 and ∼2 × 1010 cm −3 respectively. The experimental investigation of time-averaged plasma parameter reveals that their profiles remain insensitive
to ion mass and suggests that saturated slab equilibrium is obtained. Low-frequency (LF) coherent fluctuations (ω < ω
ci) are observed and identified as flute modes. Here ω
ci represents ion cyclotron frequency. Our results indicate that these modes get reduced with ion mass. The frequency of the
fluctuating mode decreases with increase in the ion mass. Further, an attempt has been made to discuss the theory of flute
modes to understand the relevance of some of our experimental observations. 相似文献