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991.
风机大型化是我国海上风电技术发展的重要方向. 东南沿海是我国海上风电发展的重要基地, 这一区域频繁发生的台风对海上风机的影响不可忽略. 台风风场与常规大风风场有不同的湍流特性, 同时台风期间较高的风速会引起巨大的台风浪. 本文考虑台风经过期间独特的风场及波浪场, 开展风浪联合作用对大型单桩海上风机影响的研究. 基于DTU 10 MW大型单桩风机, 运用一体化分析软件SIMA建立风浪联合作用下大型单桩风机的耦合数值模型, 研究台风经过不同阶段大型风力机的动力响应特性. 计算结果显示, 叶片变桨能有效降低台风经过时风机叶片所受风载荷, 变桨状态下单桩风机所受风载荷主要来源于塔筒. 在台风经过的不同阶段, 大型单桩海上风机结构表现出不同的动力特性. 台风全过程塔筒运动均受波浪激发一阶频率控制, 塔基上方结构动力载荷以惯性载荷为主, FOVS至FEWS阶段及BOVS阶段至BEWS阶段塔筒运动一阶频率处响应能量增长较小, 响应能量向低频及波频转移. 塔基下方泥面线处剪力响应受波频控制, 弯矩响应受一阶频率控制. 相似文献
992.
Zeng Liangwei Belić Milivoj R. Mihalache Dumitru Shi Jincheng Li Jiawei Li Siqi Lu Xiaowei Cai Yi Li Jingzhen 《Nonlinear dynamics》2022,108(2):1671-1680
Nonlinear Dynamics - We demonstrate the existence of various types of gap localized modes, including one- and two-dimensional (1D and 2D) single solitons and soliton clusters, as well as the... 相似文献
993.
Three hydrogen bonding complexes of the gauche‐1PA dimer (GG), trans‐1PA dimer (TT) and mixed dimer (GT) have been calculated for the geometry conformations and excited‐state energies. The electron distribution at the site of C‐O of H‐donor moiety in HOMO transfers to the direction of O‐H of H‐acceptor moiety in LUMO. The hydrogen bond between two 1PAs is the bridge of the intermolecular charge transfer. By the Zhao and Han's excited‐state hydrogen bonding dynamics rule, the first excited‐state hydrogen bonding change has been discussed without optimizing the excited‐state geometry conformations. According to the distinct difference between GT and GG (TT), we concluded that two gauche‐1PA monomers of one dimer are transformed at the same time to two trans‐1PA monomers. 相似文献
994.
Chengxiang Lu Li Chen Ronggen Ye Xufu Cai 《Journal of Macromolecular Science: Physics》2013,52(5):986-999
The chain extension behaviors of 2,2′-(1,3-phenylene)bis(2-oxazoline) (MPBO) and 2,2′-bis(2-oxazoline) (BOZ) were studied to evaluate the coupling effect on polyamide 6 (PA6) in a Haake Rheocord mixer and an extruder. The coupling results showed that there existed an optimal dosage of chain extender, lack of which caused deficiency of chain extension and excess of which led to more blocking reaction. The effect of chain extension with MPBO was shown to be inferior to BOZ. When the optimum amount of chain extenders was added in PA6, the intrinsic viscosity of the polyamide 6 increased from 1.632dl/g to 1.787dl/g(MPBO) and 2.031dl/g(BOZ), respectively. The reaction time decreased very fast with an increase in the temperature. The chain-extended products dissociated at high temperature; the degradation is suggested to proceed from the onset of the chain extension reaction, as do the coupling and blocking reactions. Furthermore, the effects of MPBO and BOZ on the thermal and mechanical properties of chain-extended PA6 were also investigated. 相似文献
995.
996.
Yaping Li Jie Shao Xudong Yu Xiufang Xu Hai Lin Zunsheng Cai Huakuan Lin 《Journal of fluorescence》2010,20(1):3-8
Two simple fluorescent anion receptors based on 1-phenyl-3-methylpyrozole-5-one-4-one phenylhydrazone (L1) and 1-phenyl-3-methylpyrozole-5-one-4-one
p-nitrophenylhydrazone (L2) were designed, synthesized and characterized with 1H NMR, COSY spectrum, 13C NMR, ESI-mass and elemental analyse. Interestingly, two receptors with similar configuration exhibited different anion binding
behaviors in DMSO solution. The results of Job plots and ESI-mass spectrum indicate that L1 bind anions such as F−, AcO−, H2PO4− to form 2:1 host-guest complexation, while L2 bind anions to form 1:1 host-guest complexation in the solution. 相似文献
997.
Yang Shi Jing Zhi Sun Anjun Qin 《Journal of polymer science. Part A, Polymer chemistry》2017,55(4):616-621
As an emerged efficient polymerization methodology, the click polymerization plays a significant role in the area of polymer and materials sciences. Similar to the click reaction, the click polymerization enjoys the advantages of high efficiency, mild reaction conditions, and high regio- and stereo-selectivity etc. In this highlight, we summarize the recent progress on click polymerizations, with focus on the alkyne-based ones. The challenges and opportunities in this area are also briefly discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 616–621 相似文献
998.
999.
1000.
Dicyclohexyldithiophosphinic acid was synthesized by a three-step strategy through the Grignard reaction of PSCl3 with cyclo-C6H11MgBr and the P-P bond-cleavage reaction of the intermediate. The 1H NMR data of ammonium dicyclohexyldithiophosphinate 4 and dicyclohexyldithiophosphinic acid 5 were characterized by 1H-1H correlation spectra. 相似文献