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51.
Winston T. Lin Yueh H. Chen TingShu Hung 《European Journal of Operational Research》2019,272(2):766-779
This paper extends previous studies to develop a partial adjustment valuation (PAV) approach in which the speeds of partial adjustment are assumed to be stochastic and dynamic over time in measuring and evaluating the values of information technology and others (e.g., e-commerce or EC, brand name, etc.). A practical application is presented to demonstrate the application of the proposed PAV approach and it is compared to the other two existing PAV approaches. 相似文献
52.
Yun‐Wen Liao Chiy‐Rong Chen Jue‐Liang Hsu Hsueh‐Ling Cheng Wen‐Ling Shih Yueh‐Hsiung Kuo Tzou‐Chi Huang Chi‐I Chang 《中国化学会会志》2011,58(7):893-898
A new sterol, 5α,6α‐epoxy‐3β‐hydroxy‐(22E,24R)‐ergosta‐8,22‐dien‐7‐one ( 1 ), together with eight known sterols, 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7α‐diol ( 2 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7β‐diol ( 3 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8(14),22‐diene‐3β,7α‐diol ( 4 ), 3β‐hydroxy‐(22E,24R)‐ergosta‐5,8,22‐trien‐7‐one ( 5 ), ergosterol peroxide ( 6 ), clerosterol ( 7 ), decortinol ( 8 ), and decortinone ( 9 ), were isolated from the stems of Momordica charantia. Their structures were elucidated by mean of extensive spectroscopic methods, including 1H, 13C, 2D‐NMR and HR‐EI‐MS, as well as comparison with the literature data. Compounds 1 , 4 , 5 , 8 , and 91 were not cytotoxic against the SK‐Hep 1 cell line. 相似文献
53.
Chung‐Shin Lu Fu‐Der Mai Yi‐Chin Wu I‐Chun Yao Peng‐Yueh Hsu Chiing‐Chang Chen 《中国化学会会志》2009,56(4):729-740
The TiO2/UV photocatalytic degradation of Michler's Ketone (MK) has been investigated in aqueous heterogeneous suspensions. Results obtained show rapid and complete oxidation of MK after 24‐h, and more than 97.5% of MK was mineralized after a 32‐h exposure to UV‐365 nm irradiation. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Nine intermediates have been detected by HPLC/ESI‐MS and GC/MS techniques. The photocatalytic degradation of MK proceeds through competitive reactions such as N‐de‐methylation and destruction of the bis‐aminobenzophenone structure. The former reaction took place in a stepwise manner to yield mono‐, di‐, tri‐, tetra‐demethylated species, while the latter reaction yielded N‐methylaminobenzene and aminobenzene. The reaction mechanisms of TiO2/UV proposed in this study should shed some light on future applications of the technology to the destruction of organic pollutants. 相似文献
54.
Wen-Chyuan Yueh Sui Sun Cheng 《International Journal of Mathematical Education in Science & Technology》2013,44(6):879-891
The discrete dynamical system of absolute differences defined by the map Ψ(x 1, x 2, x 3, x 4) = (| x 2 - x 1 |, | x 1 - x 1|, |x 1 - x 1 |, |x 1 - x 4 |) has been studied by many authors and one of the interesting questions is how to locate quadruples which converge to the fixed point (0, 0, 0, 0) in large numbers of steps. An elementary method is offered for obtaining such quadruples. The method is also able to find quadruples that will not converge to (0, 0, 0, 0). 相似文献
55.
Optical means of performing pattern recognition possessing shift-, rotation- and limited size-invariance is demonstrated. The experimental set-up is a standard Fourier transform correlator with a binary circular harmonic (CGH) filter. The filtering function of the filter is obtained by the synthetic discriminant functions (SDF) method. In the process of synthesizing the filtering function, circular harmonic functions are chosen as the basic functions. Both optical results and computer simulation results demonstrate that the filter is able to recognize the target in every rotational orientation and in the relative size range of 1–1.82. 相似文献
56.
Ching‐Kuo Lee Ming‐Hsi Yeh Tzong‐Huei Lee His‐Lin Chiu Yueh‐Hsiung Kuo 《Helvetica chimica acta》2009,92(10):1983-1989
Four unique bicyclo[3.3.1]nonadienemethanol lignans, designated lanceolatanins A ( 1 ), B ( 2 ), C ( 3 ), and D ( 4 ), along with one previously known compound, isolariciresinol ( 5 ), were isolated from the MeOH extracts of the heartwood of Cunninghamia lanceolata. Their structures were elucidated by application of various spectroscopic methods, including 1D‐ and 2D‐NMR techniques, to their acetylated derivatives 1a, 2a, 3a , and 4a . Their possible biosynthetic formations are also discussed. 相似文献
57.
Seventeen flavonoids were isolated from the roots of Scutellaria luzonica Rolfe. These compounds in elude thirteen flavones ( 1–13 ), two flavanones ( 14–15 ), a chalcone ( 16 ) and a flavone glucoside ( 17 ). 相似文献
58.
We show first that there is an error in the literature in the evaluation of the Compton scattering opacity; second, we compare the corrected values with the published ones and, third, we show that two commonly made approximations are inaccurate in the case of electron degeneracy. 相似文献
59.
The effect of the location of an impermeable barrier, which is placed for double pass in the raffinate phase, on solvent extraction through a parallel-plate membrane module, has been investigated. Theoretical predictions are in fairly good agreement with the experimental results. Considerable improvement in performance is obtainable if the subchannel width, as well as the mass-transfer area, of concurrent flow is as large as possible than that of concurrent flow, especially for low flow rate operation. It has been also checked that the hydraulic dissipated power due to the friction loss of fluid flow is very small and generally, the operating cost in all devices may be ignored. 相似文献
60.
From the roots of Rhus javanica L. var. roxburghiana, totally thirty‐seven known compounds have been isolated and identified. Their structures were elucidated based on their spectral analysis as well as comparison with authentic samples. These compounds were grouped to be fifteen triterpenoids, five steroids, two lignans, two flavonoids, nine phenolics, and four other aromatic derivatives. Their cytotoxicities toward two cell lines NUGC‐3 and HONE‐1 were also evaluated. 相似文献