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281.
On the determinacy of smooth map-germs 总被引:5,自引:0,他引:5
Andrew du Plessis 《Inventiones Mathematicae》1980,58(2):107-160
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283.
P.du T. van der Merwe 《Physics letters. A》1980,77(4):258-260
A functional method applicable to superfluid systems is proposed and the application of the general method to the derivation of equations governing the boson condensate is considered. 相似文献
284.
285.
Hrib CG Jeske J Jones PG du Mont WW 《Dalton transactions (Cambridge, England : 2003)》2007,(32):3483-3485
Formally uncharged two-coordinate tellurium atoms in trialkyl(telluroseleno)phosphonium salts [(tBu2iPrPSeTe-p-Tol)+ (p-TolTeI2)-] () and {[(iPr3PSeTeI)+]2 (TeI6)2-} () behave as soft acceptors towards iodotellurate anions, thus exhibiting a novel type of Te...Te anion-->cation donor-acceptor interaction () and a chelating TeIV(micro-I)2TeII anion-cation coordination () in the solid state. 相似文献
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287.
Wei Huang Guiju Zhang Yuxiang Zhou Cornelis A. P. Joziasse Ruyin Wang Gerrit Gobius du Sart Peng Chen 《先进技术聚合物》2024,35(3):e6345
Blending poly(butylene succinate) (PBS) with polylactide (PLLA) has proven effective in improving heat resistance of PLLA fibers. Unfortunately, it remains challenging to maintain good spinnability for PLLA/PBS blends with high content of PBS with which further improved heat resistance could be anticipated. In this study, reactive melt-extrusion was devised to in-situ generate PLLA-PBS copolymers by introducing zinc acetate as a transesterification catalyst into PLLA/PBS blends. The compatibility between the PLLA and PBS phases was greatly improved by the formation of PLLA-PBS copolymers, resulting in excellent melt-spinnability even for the PLLA/PBS blends with high PBS content up to 20 wt%. In addition, an increase in crystallinity of PLLA was achieved in PLLA/PBS blend fibers, thanks to the enhanced compatibility. More importantly, the presence of PBS nuclei retarded the molecular orientation of the amorphous PLLA phase, consistent with the effective results from the relaxation heat-setting treatment. These led to an exceptionally improved heat resistance of the PLLA/PBS blend fibers. As an encouraging result, the boiling water shrinkage was significantly reduced from ca. 20% for neat PLLA fibers to 3.7% for the PLLA/PBS blend fibers with 20 wt% PBS content. These findings may open up a facile and effective route to develop PLLA/PBS blend fibers showing sound spinnability, greatly improved heat resistance and softness. 相似文献
288.
汽油自热重整制氢反应过程分析 总被引:4,自引:1,他引:4
汽油空气自热重整制氢是解决质子交换膜燃料电池(PEMFC)氢源的重要途径。汽油中组分复杂,特别是碳原子数、分子结构相差很大时,各组分生成焓、汽化热相差很大,热力学分析表明:重整难易有较大差别,重整规律各异;另一方面,它们重整特性又有相似的一面,理论氧碳摩尔比均接近于0.31。以正辛烷自热重整反应作为模型反应,发现重整过程O2/C、H2O/C都显著影响产氢率,高水碳比时产品气废热能否尽量回收也是一个重要因素。理论上,在O2/C=0.5、H2O/C=2.0时存在最优氢产率2.1mol/mol C,这时可以得到40mol%的氢气。在本所开发的GH12汽油重整优质催化剂上,以固定床瓜尖器模拟正辛烷自热重整反应过程,发现实验结果与理论分析吻合良好。据此提出了汽油制氢合理的工艺路线。 相似文献
289.
APPLICATION OF GENETIC ALGORITHM IN PARTICLE SIZE ANALYSIS BY MULTISPECTRAL EXTINCTION MEASUREMENTS 总被引:1,自引:0,他引:1
Gerard Grhan 《中国颗粒学报》2004,2(6):235-240
Both dependent and independent model algorithms are designed with genetic algorithm (GA) to retrieve aerosol size data from multispectral extinction measurements. Compared with the traditional dependent model algorithm, e.g., simplex, GA can locate the global optimized solution instead of local ones. As an independent model algonthm, when combined with B-splines, GA gives consistent results with Chahine and Phillip-Twomey-NNLS algorithms. Numerical simulations also show that GA has high stability and good resistance to relatively higher error levels. For a population size of 50 in the present paper, the feasible ranges for genetic operators Pc and pm are found to be [0.01, 0.5] and [0.01, 0.15], respectively, and the generation number Gen_Max should be larger than 250. 相似文献
290.