Quantum electronic stability of atomically uniform films     

Luh DA  Miller T  Paggel JJ  Chou MY  Chiang TC 《Science (New York, N.Y.)》2001,292(5519):1131-1133

We have studied the structural stability of thin silver films with thicknesses of N = 1 to 15 monolayers, deposited on an Fe(100) substrate. Photoemission spectroscopy results show that films of N = 1, 2, and 5 monolayer thicknesses are structurally stable for temperatures above 800 kelvin, whereas films of other thicknesses are unstable and bifurcate into a film with N +/- 1 monolayer thicknesses at temperatures around 400 kelvin. The results are in agreement with theoretical predictions that consider the electronic energy of the quantum well associated with a particular film thickness as a significant contribution to the film stability.  相似文献   

Antimicrobial susceptibility and plasmid analysis of Actinobacillus pleuropneumoniae isolated in Taiwan.   总被引：2，自引：0，他引：2  

Chao Fu Chang  Tung Mao Yeh  Chin Cheng Chou  Yung Fu Chang  Tai Sheng Chiang 《Veterinary microbiology》2002,84(1-2):169-177

Sixty Actinobacillus pleuropneumoniae (App) strains from pigs in Taiwan were examined. Serotyping revealed that these belonged to serovars 1 (n=53), 2 (n=3), and 5 (n=4). Agar disk diffusion susceptibility testing of the isolates showed 55 (92%) were resistant to three or more antimicrobial agents. Six resistance patterns were observed. Ampicillin-chloramphenicol-flumequine-nalidixic acid-streptomycin-sulfonamide/trimethoprim-tetracycline was the most common multi-resistance pattern. Minimal inhibitory concentration of 14 antimicrobial agents was determined. The isolates were highly susceptible to ceftiofur and trimethoprim in vitro. Isolates were resistant to streptomycin, ampicillin, and nalidixic acid. All isolates were examined for the presence of plasmids using the alkaline lysis method. Forty three (72%) isolates had four plasmid bands with an approximate sizes of 3.5, 4.3, 5.8 and 6.0 kb; 12 (20%) had three bands at 3.5, 4.3 and 5.2 kb, and 5 (8%) had no plasmid bands. Antimicrobial resistance plasmids were detected in resistant strains of App. Three antimicrobial resistance plasmids were transformed into E. coli DH5 alpha. pTMY1 (4.3 kb) encoded a streptomycin kinase and a dihydropteroate synthase; pTMY2 (6.0 kb) encoded ROB-1 beta-lactamase and aminoglycoside 3'-phosphotransferase; pTMY3 (5.2 kb) encoded only ROB-1 beta-lactamase. The 4.3 kb plasmid was sequenced and consisted of 4242 bp with 42.9% GC content. The 4.3 kb plasmid DNA sequence was 98% homologous to a plasmid previously isolated from Pasteurella haemolytica.  相似文献   

Sensitivity analysis of SWAT nitrogen simulations with and without in-stream processes     

Yongping Yuan  Li-Chi Chiang 《Archives of Agronomy and Soil Science》2013,59(7):969-987

The Soil and Water Assessment Tool (SWAT) has been widely used to estimate pollutant losses from various agricultural management practices. Although many studies have shown good performance in simulating total nitrogen (TN) and dissolved nitrogen (N), the model performed poorly in many other applications, particularly on dissolved N. Poor performance on dissolved N could be attributed to landscape (in-field) processes and/or in-stream N processes in the model. Therefore, the overall goal of this study was to evaluate SWAT N simulations with in-stream processes and without in-stream processes. Sensitivity analysis results showed that when in-stream processes were not simulated, denitrification threshold water content (SDNCO), N in rainfall (RCN) and N percolation coefficient (NPERCO) were the most sensitive parameters to dissolved N losses. However, when in-stream processes were simulated, the most sensitive parameters changed to initial organic N concentration in soil layers (SOLORGN) and organic N enrichment ratio (ERORGN); and the impact of SDNCO, RCN, and NPERCO was greatly decreased. Furthermore, fertilizer timing and amount had little impact on N simulations. SWAT under-estimated dissolved N, but over-estimated organic N and TN. Further calibration could improve the simulation of dissolved N, but would degrade the simulations of organic N and TN.  相似文献   

The Fermi Gamma-Ray Space Telescope discovers the pulsar in the young galactic supernova remnant CTA 1     

Abdo AA  Ackermann M  Atwood WB  Baldini L  Ballet J  Barbiellini G  Baring MG  Bastieri D  Baughman BM  Bechtol K  Bellazzini R  Berenji B  Blandford RD  Bloom ED  Bogaert G  Bonamente E  Borgland AW  Bregeon J  Brez A  Brigida M  Bruel P  Burnett TH  Caliandro GA  Cameron RA  Caraveo PA  Carlson P  Casandjian JM  Cecchi C  Charles E  Chekhtman A  Cheung CC  Chiang J  Ciprini S  Claus R  Cohen-Tanugi J  Cominsky LR  Conrad J  Cutini S  Davis DS  Dermer CD  de Angelis A  de Palma F  Digel SW  Dormody M  do Couto E Silva E  Drell PS 《Science (New York, N.Y.)》2008,322(5905):1218-1221

Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.  相似文献   

Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles   总被引：1，自引：0，他引：1  

TS Ahmadi  ZL Wang  TC Green  A Henglein  MA El-Sayed 《Science (New York, N.Y.)》1996,272(5270):1924-1926

The shapes and sizes of platinum nanoparticles were controlled by changes in the ratio of the concentration of the capping polymer material to the concentration of the platinum cations used in the reductive synthesis of colloidal particles in solution at room temperature. Tetrahedral, cubic, irregular-prismatic, icosahedral, and cubo-octahedral particle shapes were observed, whose distribution was dependent on the concentration ratio of the capping polymer material to the platinum cation. Controlling the shape of platinum nanoparticles is potentially important in the field of catalysis.  相似文献   

Expression of a pea disease resistance response gene in the potato cultivar Shepody     

Ming-Mei Chang  Chin C. Chiang  Mark W. Martin  Lee A. Hadwiger 《American Journal of Potato Research》1993,70(9):635-647

The coding sequence from the pea disease resistance response gene 49 (DRR49 gene), was transferred into the potato (Solanum tuberosum L.) cultivar Shepody viaAgrobacterium co-cultivation. Potato leaf explants were co-cultivated withAgrobacterium tumefaciens harboring a binary vector containing the coding sequence from the DRR49 gene under the control of the 35S promoter from cauliflower mosaic virus (CaMV). Transformed potato plants were selected by their resistance to kanamycin. The insertion of foreign DNAs was detected by polymerase chain reaction (PCR) and Southern blot analysis. The expression of DRR49 coding sequence was confirmed via the detection of the corresponding mRNA in northern blot analysis. Field pathogenicity tests indicated that transgenic plants expressing the pea DRR49 mRNA have higher tuber yields than the control plants when grown in PED (potato early dying) infested soil.  相似文献   

Gene-expression profiling to identify genes related to spontaneous tumor regression in a canine cancer model     

Hsin-Chien Chiang  Albert Tai-Ching Liao  Tong-Rong Jan  Yu-Shan Wang  Han-Jung Lei  Mong-Hsun Tsai  Mo-Fen Chen  Chien-Yueh Lee  Yi-Chen Lin  Rea-Min Chu  Chen-Si Lin 《Veterinary immunology and immunopathology》2013,151(3-4):207-216

  相似文献   

Self-organizing radial basis neural network for predicting typhoon-induced losses to rice   总被引：1，自引：1，他引：0  

Fi-John Chang  Yen-Ming Chiang  Wei-Guo Cheng 《Paddy and Water Environment》2013,11(1-4):369-380

The issue of the typhoon-induced economic losses to rice is investigated. In this study, we propose a hybrid self-organizing radial basis (SORB) neural network for estimating economic losses of rice for the whole Taiwan as well as three sub-regions. The data sets of 143 typhoon events from 1961 to 2008 were collected and analyzed. Data include rice losses and typhoon-related meteorological factors. A number of different input combinations of meteorological and temporal variables are implemented to select the optimal network for predicting the losses, and a two-stage clustering method is used to explore the spatial classification of 15 counties in Taiwan into three sub-regions. The simulation results indicate that the constructed SORB network has a great ability to capture the relationship between typhoon-related variables and rice losses. Furthermore, the SORB model also demonstrates its outstanding reliability and predictability for efficiently providing a valuable reference for counties in Taiwan that could protect farmers from exposure to increasing weather-related risk and accelerate the official decision making process on compensation for rice losses after the invasion of typhoons.  相似文献   

Flexibilins A–C,New Cembrane-Type Diterpenoids from the Formosan Soft Coral,Sinularia flexibilis     

Li-Chung Hu  Jui-Hsin Su  Michael Yen-Nan Chiang  Mei-Chin Lu  Tsong-Long Hwang  Yung-Husan Chen  Wan-Ping Hu  Nai-Cheng Lin  Wei-Hsien Wang  Lee-Shing Fang  Yueh-Hsiung Kuo  Ping-Jyun Sung 《Marine drugs》2013,11(6):1999-2012

Three new cembrane-type diterpenoids, flexibilins A–C (1–3), along with a known cembrane, (−)-sandensolide (4), were isolated from the soft coral, Sinularia flexibilis. The structures of cembranes 1–4 were elucidated by spectroscopic methods. The structure of 4, including its absolute stereochemistry, was further confirmed by single-crystal X-ray diffraction analysis. Cembrane 2 displayed a moderate inhibitory effect on the release of elastase by human neutrophils.  相似文献   

Entropy and kriging approach to rainfall network design   总被引：2，自引：0，他引：2  

Hui-Chung Yeh  Yen-Chang Chen  Chiang Wei  Ru-Huei Chen 《Paddy and Water Environment》2011,9(3):343-355

Hydrological data are the basic ingredients for planning, constructing, and operating of hydraulic structures. A well-designed rainfall network can accurately provide and reflect the information of rainfall in a catchment. However, in past studies, the required number and optimal location of rain gauge stations have yet to produce a satisfactory result. A more accurate design is required. Hence, in this study, a proposed model composed of kriging and entropy with probability distribution function is introduced to relocate the rainfall network and to obtain the optimal design with the minimum number of rain gauges. The ordinary kriging is used to generate rainfall data of potential locations where rain gauge stations may be installed. The information entropy based on probability is used to measure the uncertainty of rainfall distribution. The probability distribution function will be introduced to fit the statistical characteristics of data of the rain gauges. By calculating the joint entropy and the transferable information, the relocated rain gauges are prioritized and the minimum number and location of the rain gauges in the catchment can be obtained to construct the optimal rainfall network to replace the existing rainfall network.  相似文献