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861.
862.
Chi-Shin Wang Yu-Chen Wei Ming-Lun Pan Cheng-Ham Wu Prof. Pi-Tai Chou Prof. Yao-Ting Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(34):8678-8683
A series of new [2,2]fluorenophanes has been synthesized and characterized; among them, molecules of crystallographically asymmetric anti-[2.2](1,4)(4,1)fluorenophane ( K2C -2) aggregate to form one-dimensional supramolecular chain structures through effective intermolecular π-π overlapping. This, in combination with the synergistic intramolecular π-π interaction, leads to prominent dual emission mediated by charge transfer (CT) exciton delocalization. Support of this new insight is given by mapping the transition density along the π-π packing direction where the intramolecular excitation and intermolecular CT coexist in K2C -2. 相似文献
863.
In this research, an experimental short-range visible light communication link using red-, green-, and blue-based light-emitting diodes (LEDs) for portable micro-projector applications is presented. A Reconfigurable design of a post-equalizer aimed to improve the inherent narrow modulation bandwidth of red-, green-, and blue-based LEDs has been experimentally implemented, and its effectiveness with optical filters at the receiver is investigated. Reflective liquid-crystal-on-silicon-based micro-projection architecture, widely used in portable micro-projectors, was set up to evaluate the proposed visible light communication system. The measurement results demonstrated that a significant aggregative bandwidth improvement of 162 MHz as well as an aggregative data transmission rate of nearly 400 Mb/s can be achieved by using a non-return-to-zero–on-off keying (NRZ–OOK) modulation scheme based on only one polarization state of incident light without any offline signal processing. 相似文献
864.
A discussion on the contribution of Ohta and Yamanaka [1] in this special issue, supplemented by new agent-based simulations of band collisions within the standard Vicsek-model. 相似文献
865.
Hsien-Hsin Chou Chih-Yu Hsu Ying-Chang Hsu Yu-Sheng Lin Jiann T. Lin Chiitang Tsai 《Tetrahedron》2012,68(2):767-773
New dipolar dyes containing arylamine as the electron donor, 2-cyanoacrylic acid as the acceptor, and a conjugated spacer with incorporation of 2,5-pyridyl entity have been synthesized. Photophysical and electrochemical measurements, and theoretical computation were carried on these dyes. The solar cell devices using these dyes as the sensitizers exhibited light-to-electricity efficiencies in the range of 4.28–5.27%, which reaches 60–72% of N719-based device fabricated and measured under similar conditions. Better DSSC performance can be achieved with the dye where pyridine group is attached to thienyl or fluorenyl group because of favorable resonance energy and/or coplanarity for more effective charge transfer. 相似文献
866.
Shyh‐Chi Wu Wei‐Hung Yau Chien‐Huang Tsai Chang‐Pin Chou 《Surface and interface analysis : SIA》2012,44(10):1314-1318
We present a study of the nanotribological behavior of ZnTiO3 films; the surface morphology, stoichiometry, and friction (μ) were analyzed using atomic force microscopy, X‐ray photoelectron spectroscopy, and nanoscratch system. It is confirmed that the measured values of H and μ of the ZnTiO3 films were in the range from 8.5 ± 0.4 to 5.6 ± 0.4 GPa and from 0.164 to 0.226, respectively. It is suggested that the hexagonal ZnTiO3 decomposes into cubic Zn2TiO4 and rutile TiO2 based on the thermal treatment; the H, μ, and RMS were changed owing to the grain growth and recovery that results in a relax crystallinity of ZnTiO3 films. From X‐ray photoelectron spectroscopy measured, core levels of O 1 can attribute the weaker bonds as well as lower resistance after thermal treatment. The XRD patterns showed that as‐deposited films are mainly amorphous; however, the hexagonal ZnTiO3 phase was observed with the ZnTiO3 (104), (110), (116), and (214) peaks from 620 to 820 °C, indicating that there is highly (104)‐oriented ZnTiO3 on the silicon substrate. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
867.
Phase-shifting interferometers with three piezoelectric transducers (PZTs) on their phase-shifting adapter (PSA) are widely
used in precision measurement. The guarantee of the PSA to stretch as a flat is very important to the accuracy of the measurement.
In this paper, we propose a systematic self-calibration method to calibrate the different displacements of the PZTs so that
the PSA can be moved evenly as a flat. The proposed method uses only the interference patterns to calibrate the three PZTs
and information about the exact position of the PZTs and the instrument parameters of the interferometer are not required.
Experimental results show that, after calibration by the proposed method, the deviation of the measured phase shift error
could be reduced about 43.1 times from 3.492 to 0.081°. 相似文献
868.
Yun‐Chih Lin Dr. Hung‐Lung Chou Dr. Loka Subramanyam Sarma Dr. Bing‐Joe Hwang Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(40):10658-10665
Understanding the complex thermodynamic behavior of confined amphiphilic molecules in biological or mesoporous hosts requires detailed knowledge of the stacking structures. Here, we present detailed solid‐state NMR spectroscopic investigations on 1‐butanol molecules confined in the hydrophilic mesoporous SBA‐15 host. A range of NMR spectroscopic measurements comprising of 1H spin–lattice (T1), spin–spin (T2) relaxation, 13C cross‐polarization (CP), and 1H,1H two‐dimensional nuclear Overhauser enhancement spectroscopy (1H,1H 2D NOESY) with the magic angle spinning (MAS) technique as well as static wide‐line 2H NMR spectra have been used to investigate the dynamics and to observe the stacking structure of confined 1‐butanol in SBA‐15. The results suggest that not only the molecular reorientation but also the exchange motions of confined molecules of 1‐butanol are extremely restricted in the confined space of the SBA‐15 pores. The dynamics of the confined molecules of 1‐butanol imply that the 1H,1H 2D NOESY should be an appropriate technique to observe the stacking structure of confined amphiphilc molecules. This study is the first to observe that a significant part of confined 1‐butanol molecules are orientated as tilted bilayered structures on the surface of the host SBA‐15 pores in a time‐average state by solid‐state NMR spectroscopy with the 1H,1H 2D NOESY technique. 相似文献
869.
New pyrimidine derivatives (pyr) have been synthesized using palladium-catalyzed Suzuki coupling reaction. These compounds can undergo cyclometalation with iridium trichloride to form bis-cyclometalated iridium complexes, (pyr)2Ir(acac) (acac = acetylacetonate; pyr = cyclometalated pyr). The substituents at the both cyclometalated phenyl ring and pyrimidine ring were found to affect both electrochemical and photophysical properties of the complexes. Computation results on these complexes are consistent with the electrochemical and photophysical data. The complexes are green-emitting with good solution quantum yields at ∼0.30. Light-emitting devices using these complexes as dopants were fabricated, and the device performance at 100 mA/cm2 are moderate: 9 (17 481 cd/m2, 4.8%, 18 cd/A, 5.1 lm/W); 10 (18 704 cd/m2, 4.9%, 18.9 cd/A, 4.7 lm/W); 13 (20 942 cd/m2, 5.4%, 21.0 cd/A, 6.1 lm/W). 相似文献
870.
We packed an ionic liquid (IL)-functionalized stationary phase – based on 1-octyl-3-propylimidazolium chloride covalently bounded to silica gel – into a 3.2 mm × 250 mm column for the simultaneous separation of acidic, basic, and neutral compounds using carbon dioxide subcritical/supercritical fluid chromatography (SFC), and examined the effects of the pressure, temperature, co-solvents, and additives on the retention behavior of the analytes. The model compounds tested for SFC separation are acetaminophen, metoprolol, fenoprofen, ibuprofen, naphthalene, and testosterone. The data indicate that hydrogen-bonding and hydrophobic interactions between the analytes and the IL-modified stationary phase seem to involve in the separation process. Simultaneous separation of acidic, basic, and neutral compounds via SFC was successful at a co-solvent content of 20% MeOH, a pressure of 110 bar, and a column temperature of 35 °C. The relative standard deviations of the retention times and peak areas at 50 ppm were all less than 4 and 8% (n = 6), respectively. 相似文献