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排序方式: 共有124条查询结果,搜索用时 15 毫秒
1.
维吾尔语词首音节元音声学分析 总被引:1,自引:0,他引:1
该文利用“维吾尔语语音声学参数数据库”,统计分析和归纳了维吾尔语词首音节元音的共振峰模式及其分布格局。声学元音图有多种画法,该文采用JOOS型声学元音图。这种元音图的特点是以F1为纵坐标,以F2为横坐标。这样绘制成的声学元音图与元音舌位图有很好的对应性。维语标准音词首音节中有[y, i, e, O, u, o, ;, A]等8个元音。舌位前后的分布特点是[u, o, A]为后元音,[y, i, e, O, ;]为前元音;开口度(舌位高低)分布特点是[y, i, u]为高元音,[e, O, o]为次高元音,[;]为次低元音, [A]为低元音. 相似文献
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Amino acid propensity score is one of the earliest successful methods used in protein secondary structure prediction. However, the score performs poorly on small-sized datasets and low-identity protein sequences. Based on current in silico method, secondary structure can be predicted from local folds or local protein structure. In biology, the evolution of secondary structure produces local protein structure with different lengths. To precisely predict secondary structures, we propose a derivative feature vector, DPS that utilizes the optimal length of the local protein structure. DPS is the unification of amino acid propensity score and dihedral angle score. This new feature vector is further normalized to level the edges. Prediction is performed by support vector machines (SVM) over the DPS feature vectors with class labels generated by secondary structure assignment method (SSAM) and secondary structure prediction method (SSPM). All experiments are carried out on RS126 sequences. The results from this proposed method also highlight the overall accuracy of our method compared to other state-of-the-art methods. The performance of our method was acceptable specifically in dealing with low number and low identity sequences. 相似文献
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P. Ben-Ishai E. Sader Yu. Feldman I. Felner M. Weger 《Journal of Superconductivity and Novel Magnetism》2005,18(4):455-459
We present dielectric properties of ceramic anhydrous Na0.7CoO2 and the superconducting Na0.3CoO2·1.3H2O materials. The presence of water which induces superconductivity also may increase the dielectric constant (ε) of the hydrated material. This is consistent with the predicted relationship between the highε and the enhancement ofT
c in highT
c superconductors. The anhydrous sample is porous and the transport is due to some percolation via the pores. The porosity
is much higher for the hydrated material and the transport is ionic inside bulk water. 相似文献
4.
Kasim Ocakoglu Ceylan Zafer Canan Varlikli Siddik Icli 《Materials Science in Semiconductor Processing》2013,16(6):1688-1694
A new method for synthesis of titanium dioxide (TiO2)-dye nanoparticles is reported. TiO2 nanocrystals were obtained at 150 and 200 °C by using chemically bonded TiO2-sensitizer dye as a precursor. Titanium tetraisopropoxide was first modified with a dye molecule and then precipitated by dropping into acidic water. A strongly colored precipitate was obtained. Hydrothermal growth of a colloidal solution was carried out in a Teflon-lined stainless steel autoclave. Dye sensitized solar cell efficiencies obtained were comparable and fill factor values were close to the analogous cells prepared by the use of conventional TiO2 paste techniques. This method allows the use of different substrates together with nanocrystalline TiO2 for many technological applications. 相似文献
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MA Pfaller RN Jones GV Doern HS Sader RJ Hollis SA Messer 《Canadian Metallurgical Quarterly》1998,36(7):1886-1889
An international program of surveillance of bloodstream infections (BSIs) in the United States, Canada, and South America between January and December 1997 detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in South America). Eighty percent of the BSIs were nosocomial and 50% occurred in patients hospitalized in an intensive care unit. Overall, 53.3% of the BSIs were due to Candida albicans, 15.7% were due to C. parapsilosis, 15.0% were due to C. glabrata, 7.8% were due to C. tropicalis, 2.0% were due to C. krusei, 0.7% were due to C. guilliermondii, and 5.8% were due to Candida spp. However, the distribution of species varied markedly by country. In the United States, 43.8% of BSIs were due to non-C. albicans species. C. glabrata was the most common non-C. albicans species in the United States. The proportion of non-C. albicans BSIs was slightly higher in Canada (47.5%), where C. parapsilosis, not C. glabrata, was the most common non-C. albicans species. C. albicans accounted for 40.5% of all BSIs in South America, followed by C. parapsilosis (38.1%) and C. tropicalis (11.9%). Only one BSI due to C. glabrata was observed in South American hospitals. Among the different species of Candida, resistance to fluconazole (MIC, > or = 64 microg/ml) and itraconazole (MIC, > or = 1.0 microg/ml) was observed with C. glabrata and C. krusei and was observed more rarely among other species. Isolates of C. albicans, C. parapsilosis, C. tropicalis, and C. guilliermondii were all highly susceptible to both fluconazole (99.4 to 100% susceptibility) and itraconazole (95.8 to 100% susceptibility). In contrast, 8.7% of C. glabrata isolates (MIC at which 90% of isolates are inhibited [MIC90], 32 microg/ml) and 100% of C. krusei isolates were resistant to fluconazole, and 36.9% of C. glabrata isolates (MIC90, 2.0 microg/ml) and 66.6% of C. krusei isolates were resistant to itraconazole. Within each species there were no geographic differences in susceptibility to fluconazole or itraconazole. 相似文献
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A semianalytical method of analysis for arbitrary weakly guiding circular and noncircular profiles, which has its fundamental basis in perturbation theory and incorporates Green's function and integral equation techniques in a powerful method of analysis possessing extremely high accuracy, is extended to the analysis of higher order modes and cutoff frequencies of arbitrary weakly guiding circular and noncircular profiles. Its accuracy is demonstrated by its application to several weakly guiding profiles, for which the method is found to be extremely accurate (<10-5%). Furthermore, additional simplifications to the semianalytical method of analysis are presented, which dramatically reduce the number of calculations required for solution 相似文献