Search

Your search keyword '"Cheng, Chung-Chih"' showing total 39 results
Start Over Author "Cheng, Chung-Chih"
39 results on '"Cheng, Chung-Chih"'

4. Ground and excited-state acetic acid catalyzed double proton transfer in 2-aminopyridine

Author

Hung Fa-Tsai, Hu Wei-Ping, Li Tsung-Hui, Cheng Chung-Chih, and Chou Pi-Tai

Subjects
Aminopyridines -- Atomic properties, Hydrogen bonding -- Analysis, Protons -- Observations, Acetic acid -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

Theoretical calculations on the ground and excited state double proton transfer in the 2-aminopyridine acetic acid dual hydrogen-bonded system are performed. The sequence of the asynchronous double proton transfer correlates with the hydrogen-bonding strength.

Published
2003

9. Excited-state double-proton transfer on 3-methyl-7-azaindole in a single crystal: deuterium isotope/tunneling effect

Author

Yu, Wei-Shan, Cheng, Chung-Chih, Chang, Chen-Pin, Wu, Guo-Ray, Hsu, Chin-Hao, and Chou, Pi-Tai

Subjects
Charge transfer -- Analysis, Structural dynamics -- Analysis, Methyl groups -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

A study is conducted to evaluate 3-methyl-7-azaindole, of which the photostability is superior to that of 3IAI. The results provide an ideal model to investigate the intrinsic Excited-state Double-Proton Transfer (ESDPT) dynamics for 7-azaindole analogues in which the structural information is well documented.

Published
2002

16. A Fastest Patchwise Histogram Construction Algorithm based on Cloud-Computing Architecture

Author

Huang, Shih-Chia, Cheng, Chung-Chih, Cheng, Fan-Chieh, Lin, Po-Hsiung, and Huang, Wen-Tzeng

Abstract

The histogram in each patch of the input image is a useful feature applied for various development of image processing techniques. However, if the size of the input image is very large, the histogram construction of each patch in the image becomes very time-consuming. For applications involving the processing of several very large images, this paper proposes a superior patchwise histogram construction algorithm based on cloud-computing architecture that is faster than similar state-of-the-art approaches. Through the modern communication network, the computation cost can be easily shared to construct several patchwise histograms at the same time. The proposed algorithm is the fastest solution in the field as well as applicable to various data processing procedures related to probability distribution. Experimental results show that the proposed algorithm has the best performance compared to other related algorithms.

Published
2017
Full Text
View/download PDF

25. Syntheses and remarkable photophysical properties of 5-(2-pyridyl) pyrazolate boron complexes; photoinduced electron transferElectronic supplementary information (ESI) available: Photophysical experimental details, the spectral data of all boron complexes, and crystal data of 2a. See http://www.rsc.org/suppdata/cc/b3/b309374c/

Author

Cheng, Chung-Chih, primary, Yu, Wei-Shan, additional, Chou, Pi-Tai, additional, Peng, Shie-Ming, additional, Lee, Gene-Hsiang, additional, Wu, Pei-Chi, additional, Song, Yi-Hwa, additional, and Chi, Yun, additional

Published
2003
Full Text
View/download PDF

31. Photoinduced double proton tautomerism in 4-azabenzimidazole

Author

Chou, Pi-Tai, Wu, Guo-Ray, Wie, Ching-Yen, Cheng, Chung-Chih, Chang, Chen-Pin, and Hung, Fa-Tsai

Subjects
Chemical research -- Analysis, Chemistry, Physical and theoretical -- Research, Chemicals, plastics and rubber industries
Abstract

Issues concerning the use of theoretical calculations, absorption and emission to investigate the hydrogen-bonded complexes of 4-azabenzimidazole are discussed.

Published
1999

32. Phase control of cubic SBA-1 mesostructures viaalcohol-assisted synthesisElectronic supplementary information (ESI) available: powder XRD patterns. See http://dx.doi.org/10.1039/b504320d

Author

Kao, Hsien-Ming, Cheng, Chung-Chih, Ting, Chun-Chiang, and Hwang, Li-Yung

Abstract

The addition of short-chain alcohols such as methanol, ethanol, or polyols glycerol and d-sorbitol as cosolvents offers an effective synthetic approach for controlling the phase behavior of cubic SBA-1 Pm3nmesophase over a broad temperature range.

Published
2005
Full Text
View/download PDF

33. ANALYSIS OF JUNCTION TRANSISTOR CONVERTERS

Author

Cheng Chung-Chih

Subjects
Materials science, business.industry, Heterostructure-emitter bipolar transistor, Optical transistor, Bipolar junction transistor, General Physics and Astronomy, Optoelectronics, Multiple-emitter transistor, Field-effect transistor, High-electron-mobility transistor, Converters, business, Static induction transistor
Published
1959

34. ANALYSIS OF THE NONLINEAR CHARACTERISTICS AND THE PUMPED TIME-VARYING PARAMETERS OF THE VARACTORS

Author

Cheng Chung-Chih and Ho Shih-Zhe

Subjects
Normalization (statistics), Engineering, Voltage ratio, business.industry, Physics::Optics, General Physics and Astronomy, Physics::Classical Physics, Power (physics), Nonlinear system, Harmonics, Electronic engineering, business, Varicap, Parametric statistics
Abstract

One of the most fundamental quantities in the study of various parametric applications of the varactors is its nonlinear characteristics. The required pumping power can be greatly reduced if a varactor having much higher nonlinearity is employed. For the purpose of studying either lower pumping applications or non-sinusoidal pumping applications of the varactor, a knowledge of both the fundamental and the harmonics of the pumped time-varying parameters of the varactors is highly desirable. An analysis on the proper selection and normalization of the non-linear characteristics of the varactor is offered. A graphical method to analyze the fundamental and the harmonics of the pumped time-varying parameters was employed, and curves relating these components to the nonlinearity of the varactor γ, and the pumping voltage ratio m 1 were obtained. These curves serve as one of the fundamental references in various varactor parametric applications. Sample applications are also included as illustrations.

Published
1965

37. Photoinduced electron transfer reaction tuned by donor–acceptor pairs via the rigid, linear spacer heptacyclo[6.6.0.02,6.03,13.04,11.05,9.010,14]tetradecane

Author

Chow, Tahsin J., Chiu, Nan-Rong, Chen, Hong-Chuan, Chen, Chong-Yow, Yu, Wei-Shan, Cheng, Yi-Ming, Cheng, Chung-Chih, Chang, Chen-Pin, and Chou, Pi-Tai

Subjects
*CHARGE exchange, *ELECTRONIC structure
Abstract

A new class of donor-{saturated hydrocarbon bridge}-acceptor (D–B–A) dyads were synthesized and utilized on a systematic approach to evaluate the corresponding photoinduced electron transfer (ET) process. Among these dyads heptacyclo[6.6.0.02,6.03,13.04,11. 05,9.010,14]tetradecane (HCTD) was used as a unique spacer, which possesses a geometry of high symmetry (D2d), rigidity and linearity. The spectroscopy and dynamics of excited-state ET as functions of donor/acceptor electronic states, orientation as well as solvent properties were analyzed with the aid of theoretical computations. It was observed that the quenching of donor fluorescence (the F1 band) correlated with the appearance of a broad charge-transfer (CT) emission. Both wavelength and intensity of the CT band varied with solvent-polarity, whereas its rise dynamics complied well with the decay of the F1 band. In acetonitrile, the CT state decays much faster than the rate of ET (∼63 ps−1) so that the corresponding steady-state emission cannot be resolved. An intriguing effect was observed in the case of benzene-1,2-dithioketals (3a and 3b) where the D and A π-chromophores were aligned in different orientations. The estimated ET rate of 3a (3.9×1010 s−1) was substantially faster than that of 3b (7×108 s−1). The experimental data were tentatively fitted by a semi-log plot of ET rate constants (ket) against free energy (ΔG0), yielding a value of ∼17.3 cm−1 for the electron-coupling matrix (Hel). [Copyright &y& Elsevier]

Published
2003
Full Text
View/download PDF

38. 2,7-Bis(1H-pyrrol-2-yl)ethynyl-1,8-naphthyridine: an ultrasensitive fluorescent probe for glucopyranoside.

Author

Liao JH, Chen CT, Chou HC, Cheng CC, Chou PT, Fang JM, Slanina Z, and Chow TJ

Subjects
Binding Sites, Fluorescent Dyes chemical synthesis, Hydrogen Bonding, Molecular Structure, Sensitivity and Specificity, Spectrum Analysis, Glucosides analysis, Naphthyridines chemical synthesis, Naphthyridines chemistry, Pyrroles chemical synthesis, Pyrroles chemistry
Abstract

[structure: see text] A push-pull conjugated molecule, 2,7-bis(1H-pyrrol-2-yl)ethynyl-1,8-naphthyridine (BPN), has been designed to bind selectively with octyl glucopyranoside (OGU). The BPN/OGU quadruple hydrogen-bonding complex adopts a rigid BPN conformation in which the proton donor (d) and acceptor (a) relays (daad) are resonantly conjugated through the ethynyl bridge, inducing pi-electron delocalization, i.e., a charge transfer effect. The excellent photophysical properties make BPN a highly sensitive probe for monitoring glucopyranoside to a detection limit of approximately 100 pM.

Published
2002
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results