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991.
992.
流场中聚合物共混体系液滴形变的理论模型 总被引:3,自引:0,他引:3
讨论了两相聚合物共混体系中,悬浮于另一种牛顿(或粘弹)液体中的牛顿(或粘弹)液滴的形变理论模型.影响液滴形变的主要因素有两相的组成、粘度比和弹性比、动态界面张力、临界界面张力系数,外流场形式及其强度.对于两相均为牛顿流体的体系,理论预测能够与实验相符;对于两相(或其中一相)为粘弹流体的体系,由于弹性的影响而使液滴形变的研究变得复杂,理论模型尚需完善.建立完整的液滴形变理论模型还需深入研究界面层、微观分子形变、液滴之间及液滴和连续相介质之间的相互作用对液滴形变的影响 相似文献
993.
Part I presented a set of experiments in which pressurized tubes were cycled axially under stress control about a compressive mean stress. This loading history causes biaxial ratcheting involving compressive axial strain and expansion of the diameter of the tube. The compressive strain in turn induces the initiation and growth of axisymmetric wrinkles. Persistent cycling resulted in localization of the wrinkles and collapse. In Part II the problem is first modeled as a shell with initial axisymmetric imperfections while the biaxial ratcheting of the material is modeled using the Dafalias–Popov two-surface nonlinear kinematic hardening model. It is demonstrated that when suitably calibrated this modeling framework reproduces the prevalent ratcheting deformations and the evolution of wrinkling including the conditions at collapse accurately for all experiments. The calibrated model is then used to evaluate the ratcheting behavior of pipes under thermal-pressure cyclic loading histories experienced by axially restrained pipelines. 相似文献
994.
A modified shakedown theorem and its solving technique are presented to involve hydrogen embrittlement of steel into limit and shakedown analysis. Firstly, the shakedown theorem for hydrogen embrittled material is derived from a limited kinematic hardening shakedown theorem and hydrogen enhanced localized plasticity mechanism of hydrogen embrittlement. In the presented theorem, hydrogen’s effect is taken into account by the synergistic action of both strength reduction and stress redistribution. Secondly, a novel solving technique is developed based on the basis reduction method, in which the complicated constraints in the resulting nonlinear mathematical programming are released. At last, three numerical examples are carried out to verify the performance of the proposed method and to reveal hydrogen’s effect on the limit and shakedown load of structure. The numerical results are discussed and compared with those from literatures, which proves the accuracy and high efficiency of the introduced solving technique. It is concluded that the proposed theorem can predict the limit and shakedown load of hydrogen embrittled structure reasonably. 相似文献
995.
Hou Chenxi He Hui Sun Jinjie Yang Bei Fang Haofan Jiao Caishan He Mingjian 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2245-2252
Journal of Radioanalytical and Nuclear Chemistry - The effects of different dissolution parameters (solid–liquid ratio, peroxide concentration, carbonate concentration, countercation and pH)... 相似文献
996.
复杂组分在传感界面的非特异性吸附会严重影响传感器的灵敏度与准确度。虽然构建致密的亲水性抗污涂层能够抑制表面非特异性吸附,但是其绝缘性又会显著增大传感界面阻抗,严重削弱响应电流。因此,如何兼顾传感界面抗污性与导电性,构建灵敏的传感基底是电化学免疫传感器目前急需解决的关键问题。为此,利用镓化铟液态金属(Liquid Metal, LM)原位引发乙烯基吡咯烷酮(N-vinylprrolidone, NVP)聚合,同时利用壳聚糖(Chitosan, CS)与聚乙烯基吡咯烷酮(poly(N-vinylprrolidone), pNVP)之间强烈的氢键结合作用,再分步交联成功获得一种半互穿网络水凝胶传感界面,并以此构建电化学免疫传感器。研究表明,所构建的传感器能够对胃动素实现灵敏检测,线性范围为10 pg/mL~10 μg/mL,检测限为6.91 pg/mL(S/N=3),并且在5%的血清样品中检测结果不受影响。此外,所构建的免疫传感器也显示出优异的重复性、稳定性和选择性。以上结果成功证明了基于液态金属纳米复合凝胶作为电化学传感基底的可行性,也为其它电化学免疫传感器的构建提供重要的借鉴意义。 相似文献
997.
998.
Jiao Jiao Qing-Yan Gai Lin Zhang Wei Wang Meng Luo Yuan-Gang Zu Yu-Jie Fu 《Analytical and bioanalytical chemistry》2015,407(16):4841-4848
999.
Lin Yang Lifang Jiao Yanli Miao Huatang Yuan 《Journal of Solid State Electrochemistry》2009,13(10):1541-1544
The olivine-type cathode materials of LiFePO4 were prepared via solid-state reaction under argon atmosphere and doped by chlorine to improve their electrochemical performances.
The crystal structure, morphology, and electrochemical properties of the prepared samples were investigated using thermogravimetry–differential
scanning calorimetry, X-ray diffraction, Fourier transform infrared, scanning electron microscopy, cyclic voltammetry, and
charge–discharge cycle measurements. The result showed that the electrochemical performance of LiFePO4 had been improved by chlorine doping, and the effect of chlorine in lattice was discussed. The heavily doped samples show
better electrochemical performance in relative high rates. 相似文献
1000.
Shen L Jiao RH Ye YH Wang XT Xu C Song YC Zhu HL Tan RX 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(21):5596-5602
Three new cytotoxic 10,13-cyclotrichothecane-derived macrolides, myrothecines A-C (1-3), were characterized from the extracts of two Myrothecium roridum strains, IFB-E009 and IFB-E012, isolated as endophytic fungi found on the traditional Chinese medicinal plants Trachelospermum jasminoides and Artemisia annua, respectively. The absolute configuration of myrothecines A-C was elucidated by a combination of spectral techniques (UV, IR, MS, circular dichroism (CD), (1)H and (13)C NMR, DEPT, (1)H-(1)H COSY, NOESY, HMQC, and HMBC spectrascopic analyses), Mosher's ester analysis, and single-crystal X-ray diffraction. The absolute configuration of the reported bioactive analogue, mytoxin B was established by correlating its spectral data with that of known absolute configurational structures. Furthermore, the significance in endophytism (or symbiosis) and biocatabolism, highlighted by production of those macrolides by the endophytic strains, is discussed in brief. 相似文献