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本文以五跨双塔自锚式悬索桥——成都云龙湾大桥为工程背景,通过建立有限元模型,对该桥空间结构静力特性进行了分析与研究.根据设计需求,分析并讨论了恒载、活载、温度等效应对结构受力的影响,并进行了荷载效应组合下结构受力性能检算,为桥梁设计、施工和运营提供理论依据,同时也为同类型桥梁的设计研究提供参考. 相似文献
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A new class of biobased thermoset resins, methacrylated four‐armed star‐shaped polylactides (M4sPLAs), was prepared. The effect of star architecture, e.g. varying arm length, on the properties of the cured products was examined. Based on differential scanning calorimetry, the non‐isothermal and isothermal curing behaviors of these M4sPLAs were investigated. Various curing kinetic parameters were obtained and elucidated using autocatalytic reaction models. Experimental results indicate that the oligomers can be crosslinked into a rigid network within a curing time varying from several minutes to more than an hour upon thermal initiation. The curing processes of M4sPLAs with varying arm length are different and complex, as indicated by the change of various kinetic parameters, reaction orders and evolutions of activation energy under the test reaction conditions. High crosslinking density is especially effective for improving the thermal stability of polylactide, but also leads to slower degradation rate and deterioration of its impact properties. Copyright © 2012 Society of Chemical Industry 相似文献
995.
Kefeng Wang Yang Leng Xiong Lu Fuzeng Ren 《Materials science & engineering. C, Materials for biological applications》2013,33(6):3245-3255
Proteins play an important role in the process of biomineralization, which is considered the critical process of new bone formation. The calcium phosphate (Ca-P) mineralization happened on hydroxyapatite (HA), β-tricalcium phosphate (β-TCP) and biphasic calcium phosphate (BCP) when proteins presented were investigated systematically. The results reveal that the presence of protein in the revised simulated body fluid (RSBF) did not alter the shape and crystal structure of the precipitated micro-crystals in the Ca-P layer formed on the three types of bioceramics. However, the morphology of the Ca-P precipitates was regulated but the structure of Ca-P crystal was unchanged in vivo. The presence of proteins always inhibits Ca-P mineralization in RSBF and the degree of inhibitory effect is concentration dependent. Furthermore, Protein presence can increase the possibility of HA precipitation in vitro and in vivo. The results obtained in this study can be helpful for better understanding the mechanism of biomineralization induced by the Ca-P bioceramics. 相似文献
996.
Research has emphasized the importance of employees' individual entrepreneurial decision making for innovation. In this context, practised creativity as the ability to perceive and exploit creative opportunities, can be regarded as a crucial requirement for employees in new product development. We discuss the application of decision making logic as an important antecedent of practised creativity in new product development. We survey 219 employees from new product development departments of German product and service firms. Results indicate that the use of entrepreneurial decision making logic positively impacts practised creativity; comparably we find indicators that the use of causal decision making logic negatively influences creativity. The effects significantly depend on the moderating role of uncertainty. The results contribute to the literature of creativity, entrepreneurship and new product development by theoretically and empirically revealing effectuation as antecedent to practised creativity. The results open promising avenues for future research and allow the derivation of valuable guidelines for practitioners. Aligning the new product development process to support employees' entrepreneurial decision making may help generating practised creativity. 相似文献
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High-efficiency multipartite entanglement purification of electron-spin states with charge detection
Tao Li Bao-Cang Ren Hai-Rui Wei Ming Hua Fu-Guo Deng 《Quantum Information Processing》2013,12(2):855-876
We present a high-efficiency multipartite entanglement purification protocol (MEPP) for electron-spin systems in a Greenberger–Horne–Zeilinger state based on their spins and their charges. Our MEPP contains two parts. The first part is our normal MEPP with which the parties can obtain a high-fidelity N-electron ensemble directly, similar to the MEPP with controlled-not gates. The second one is our recycling MEPP with entanglement link from N′-electron subsystems (2 < N′ < N). It is interesting to show that the N′-electron subsystems can be obtained efficiently by measuring the electrons with potential bit-flip errors from the instances which are useless and are just discarded in all existing conventional MEPPs. Combining these two parts, our MEPP has the advantage of the efficiency higher than other MEPPs largely for electron-spin systems. 相似文献
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