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81.
H. Wiedersich 《辐射效应与固体损伤》2013,168(1-3):97-107
Abstract For quantitative predictions and comparisons of microstructures that evolve during exposure to different radiation environments at elevated temperature one needs to develop methods that go beyond those based on the number of displacements per atom. The number of freely migrating defects that contribute to the microstructural development is far less than the total number of defects produced, as has been recognized for some time from measurements of radiation-induced segregation and of radiation-enhanced diffusion. Defect production in various neutron and ion irradiation environments is discussed in light of this fact. A method to calculate the fraction of freely migrating defects from the cluster size distribution of defects produced in cascades is suggested. The results are in good agreement with available data. 相似文献
82.
K. Uhlig 《Isotopes in environmental and health studies》2013,49(2):37-42
0. Einleitwng 1. Reaktorwissenschaft und -technik und Kernenergetik 2. Kerntechnischer Gerätebau 3. Produktion von Isotopenerzeugnissen 4. Strahlenschulz und Schutztechnik 5. Isotopenanwendung 6. Strahlentechnik 7. Zur weiteren Tätigkeit der Ständigen Kommission Atomenergie des RGW 相似文献
83.
提出了一种新的能反映决策者满意度的随机变量序关系,并据此研究了随机不等式的确定性等价类,方法被称为满意度方法.最后将其应用于带凹性生产成本运输问题的求解中,并将方法与常用的机会约束方法进行比较,说明满意度法不仅合理可行,而且当决策者对约束条件的要求越高时,它所得最优值越优于机会约束法所得最优值. 相似文献
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85.
Ashkan Reisi-Dehkordi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):642-647
Nowadays, quantification of the effects of basic parameters such as precursor, temperature oxidation, residence time, low temperature carbonization (LTC) and high temperature carbonization (HTC) on production process polyacrylonitrile based carbon fibers is not completely understood. In this way, there is not a completely theoretical model that accomplishes to quantitatively describe production process carbon fibers very accurately which needs to be used by engineers in design, simulation and operation of that process. This paper presents the development of a back propagation neural network model for the prediction of carbon fibers produced from PAN fibers. The model is based on experimental data. The precursors, temperature oxidation, residence time, LTC and HTC have been considered as the input parameters and the strength as output parameter to develop the model. The developed model is then compared with experimental results and it is found that the results obtained from the neural network model are accurate in predicting the strength of carbon fibers. 相似文献
86.
通过将2个4,4''-联吡啶基团用偶氮基团连接,我们合成了新的配体顺式-和反式-1,2-二((4,4''-联吡啶)-3-氮烯)(cis-L和trans-L),并利用trans-L与银离子和钴离子构筑了配位聚合物{[Ag2(trans-L)(ClO4)2]·4CH3CN}n(1)和{[Co(trans-L)2(H2O)2](ClO4)2}n(2)。其中1为一维梯形链,链与链之间通过π-π以及Ag…Ag相互作用堆积;2为三维无限dendrimer结构,其Co中心具有合适的氧化还原电位,在以荧光素为光敏剂的条件下,可作为光催化剂实现光解水放氢。 相似文献
87.
以母体配合物[Fe2(CO)6(μ-SCH2CH(CH2CH3)S)](1)分别与三(2-呋喃基)膦、二苯基丙基膦、双(二苯基膦)乙炔、1,2-双(二苯基膦基)苯和脱羰试剂Me3NO·2H2O反应,制备了单取代配合物[Fe2(CO)5(L)(μ-SCH2CH(CH2CH3)S)](L=P(2-C4H3O)3,2;Ph2PCH2CH2CH3,3)、桥联配合物{[Fe2(CO)5(μ-SCH2CH(CH2CH3)S)]2(Ph2PC≡CPPh2)}(4)和螯合配合物[Fe2(CO)4(κ2-(Ph2P)2(1,2-C6H4))(μ-SCH2CH(CH2CH3)S)](5)。配合物2~5经元素分析、红外光谱、核磁共振氢谱和磷谱表征,并进一步得到单晶X射线衍射的确证。电化学研究表明,在弱酸HOAc作为质子源存在的情况下,这些配合物可以实现催化质子还原产生氢气的功能。 相似文献
88.
89.
Abstract The aliphatic polyesters are normally synthesized by ester interchange reactions or direct esterification of hydroxyacids or diacid/diol combinations. Biotransformation, utilizing the enzymes as catalysts, was accepted as an alternative route for the synthesis of aliphatic polyesters and offers various advantages compared with the conventional, metal-catalyzed polymerization reactions. Previous studies indicated that lipase-catalyzed polycondensation reactions between diols and diacids occurred preferentially at primary hydroxyl groups of diols, when diols contained both primary and secondary hydroxyl groups. In this work, we investigated lipase-catalyzed polycondensation of diacids and secondary hydroxyl group–containing diols, and successfully synthesized polyesters by polycondensation with secondary hydroxyl groups as well as primary hydroxyl groups. Various diols, glycerol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, and 2,4-pentanediol were tested for the polycondensation. The polymerization was achieved by heating a mixture of lipase B, sebacic acid, and the diols in anhydrous toluene at 100 °C for 72 h. The resulting polymers were characterized by 1H and 13C NMR spectroscopy, Fourier transform–infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography. 相似文献
90.
Salah Abd El Wanees Sabry Hamed Seda 《Journal of Dispersion Science and Technology》2013,34(12):1813-1826
AbstractThe kinetics of H2 production during Zn corrosion in 0.5?M HCl without and with various additives of N,N'-bis-(1-hydroxyphenylimine)-2,5-thiophenedicarboxaldehyde (HPTD) was studied using gasometry and electrochemical techniques. The surface of the corroded Zn samples was investigated using SEM and Optical Profilometry. The rate of H2 production (RHP) increased with the immersion time and temperature. Presence of HPTD mitigated RHP due to an adsorption process. The electrochemical impedance spectroscopy showed that HPTD had a good inhibitive effect. Polarization data proved that HPTD acted as a surface-active mixed-type inhibitor. Some thermodynamic parameters were deduced and discussed. Theoretical calculations were also conducted to corroborate the capability of HPTD to protect Zn surface from corrosion process. 相似文献