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61.
基于以前的偏滤器研究,提出了中国核聚变工程实验堆(CFETR)偏滤器靶板的概念设计.在最差工况下进行的热工水力分析和力学分析表明,应力和温度都在允许范围内,验证了该设计模型的可靠性.该概念模型和对其所做的分析可以为以后的工程设计提供参考. 相似文献
62.
63.
Zhengjun Liu Lie XuChuang Lin Jingmin DaiShutian Liu 《Optics and Lasers in Engineering》2011,49(4):542-546
An image encryption is discussed based on the random phase encoding method in gyrator domains. An iterative structure of image encryption is designed for introducing more random phases to encrypt image. These random phase functions are generated by a two-dimensional chaotic mapping with the help of computer. The random phases are utilized for increasing the security of this encryption algorithm. In the chaotic mapping relation, the initial value and expression can serve as the key of algorithm. The mapping relation is considered secretly for storage and transmission in practical application in comparison to traditional algorithms. The angle parameter of gyrator transform is an additional key. Some numerical simulations have been given to validate the performance of the encryption scheme. 相似文献
64.
应用原子吸收光谱法测定了内蒙古地产的笃斯茎、叶中的Cu,Fe,Zn,Mn,Ca,Mg等六种人体必需微量元素及宏量元素的含量。从而为评价笃斯的品质及其药理、药效提供了具有一定价值的数据。 相似文献
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66.
用手性配体改性铝锂试剂对芳香酮的还原 总被引:1,自引:0,他引:1
用手性一元酮作辅助配体,与1,2,5,6-二丙酮甘iAlh5对芳香酮进行对映选择 的,得到光学活性产物8个。通过与α-乙酰氧基-L-丙酰氯生成非对映异构体酯,经气相色谱分析,芳酮挑学产率为23.3 ̄71.2%。初步探讨了配体之间对称性匹配的情况。 相似文献
67.
Xun Chen Lie Chen Yiwang Chen 《Journal of polymer science. Part A, Polymer chemistry》2013,51(19):4156-4166
Three different types of photocrosslinkable groups into a low band‐gap donor–acceptor‐conjugated polymer, namely poly{benzo[1,2‐b:4,5‐b′]dithiophene‐alt‐ thieno[3,4‐b]thiophene} (PBT), were developed to comparatively investigate the effect of the photocrosslinkable groups on the thermal stability of bulk heterojunction solar cells. Compared with vinyl groups, bromine‐ and azide‐ photocrosslinkable groups are more prompt for photocrosslinking to yield a denser crosslinking network, probably due to the different crosslinking mechanisms and reaction rates. In contrast to the reference device decreasing to less than 10% of its initial efficiency value after 80 h of annealing at 150 °C, a great improvement in the thermal stability of performance of all these crosslinked functional copolymers devices demonstrates that photocrosslinking can effectively improve the thermal stability of the active layer by suppressing [6,6]‐phenyl‐C61‐butyric acid methyl diffusion and phase separation. Furthermore, the solar cells with crosslinked bromine‐ and azide‐functionalized PBT polymers showed very thermally stable photovoltaic device performance by retaining 78 and 66% of their initial device efficiency, respectively, whereas vinyl‐functionalized PBT devices retained only 51% of its initial value after long‐time thermal annealing. This suggests that an appropriate crosslinking network with homogenous active morphology could dramatically enhance the device stability without sacrificing the performance. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4156–4166 相似文献
68.
The suitability of thallium halide electrodeless discharge tubes as a radiation source for atomic fluorescence was investigated. Effects of various parameters, affecting the emission intensities, were investigated. 相似文献
69.
Zhiyi Li Stefanie Tomasch Zhi X. Chen Alessandro Parente Ivar S. Ertesvåg Nedunchezhian Swaminathan 《Proceedings of the Combustion Institute》2021,38(4):5423-5432
A cylindrical confined combustor operating under MILD condition is investigated using LES. The combustion and its interaction with turbulence are modeled using two reactor based models, PaSR and EDC. Results show that the Partially Stirred Reactor (PaSR) model yields improved estimation for mean temperature and species mole fractions compared to Eddy Dissipation Concept (EDC). LES data are analysed using advanced post-processing methods such as the chemical Tangential Stretching Rate (TSR), balance analysis and local Principle Component (PCA) analysis. TSR can identify chemical explosive (ignition-like) and contractive (burnt) regions. With the balance analysis of the convective, diffusive and reactive terms in temperature equation, regions with substantial heat release coming from ignition or flame are identified. The local PCA analysis classifies the whole domain into clusters (regions with specific features) and provides the leading species in each cluster. The three analyses correlate well with one another and it is observed that the most chemically active region locates upstream (in the near-field). Also, both autoignition and flame-like structures play equally important roles in MILD combustion. 相似文献
70.
<正>The conformations ofγ-butyrolactone ring in solution were deduced on the basis of ~1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1'-alkoxyl-1'-carbalkoxy-methylene)-5(R)[(1R)-menthyloxy]-γ-butyr-olactones with a stable planar conformation of γ-butyrolactone ring were found. 相似文献