摘要：为了提高传统风能最大功率点跟踪控制的鲁棒性,提出了新的滑模自适应最大功率点跟踪控制策略。由于实际无速度传感器的风电系统变量难以测量,为此构造了滑模状态观测器来估计系统的转速跟踪误差,并基于估计值设计了滑模自适应最大功率点跟踪控制器。最后,基于MATLAB/Simulink仿真平台搭建了完整的风电系统仿真模型。仿真结果表明,在不同风速扰动作用下,所提出的控制策略均能实现良好的跟踪和控制效果,提高了风电系统的鲁棒性,保证了风电系统的最大功率输出。

摘要：针对含柴油发电机和储能的混合电力系统,提出了一种频率协调控制策略。设计了滑模负荷频率控制器以调节柴油发电机出力,通过配置适当容量的储能设备进一步优化系统频率。最后通过MATLAB/Simulink仿真平台进行了验证。结果表明,所提出的协调控制策略能够有效减小电力系统频率偏差,且具有较好的鲁棒性。

摘要：扼要回顾了我国走航式海洋测量作业平台的研制历程,提出了通用走航式海洋测量作业平台研制的总体目标、设计原则、功能需求,介绍了该平台软件硬件研制实现及其主要性能、功能技术指标,以及平台的应用情况,最后对平台的未来发展进行了展望。

摘要：目的探讨西安市孕晚期孕妇分娩后6个月内纯母乳喂养意愿及其影响因素。方法采用便利抽样法,选取2019年1—2月在西安市5家医院产科门诊行规律产检的2671名孕晚期孕妇为研究对象进行横断面调查。通过现场调查的方式使用自行设计的孕晚期孕妇纯母乳喂养意愿调查问卷对孕妇进行调查。采用多因素Logistic回归分析孕晚期孕妇纯母乳喂养意愿影响因素。共发放调查问卷2671份,回收有效问卷2479份,有效回收率为92.8%(2479/2671)。结果60.8%(1507/2479)的孕妇计划在产后6个月内进行纯母乳喂养。丈夫(OR=2.950,95%CI:2.097~4.066)和家人(OR=2.171,95%CI:1.571~3.000)支持纯母乳喂养的孕晚期孕妇有更高的纯母乳喂养意愿,参加母乳喂养课程的孕妇纯母乳喂养意愿较高(OR=1.436,95%CI:1.199~1.719)。结论超过一半的孕晚期孕妇产后6个月内计划进行纯母乳喂养,丈夫和家人支持及参加母乳喂养课程使孕妇有更高的纯母乳喂养的意愿。应开展产前母乳喂养课程教育,以提高孕妇和家庭成员对纯母乳喂养的认识,并注重丈夫及家庭成员对纯母乳喂养的支持,以提高分娩后6个月内纯母乳喂养率。

摘要：这是我国第一台少数民族载歌载舞喜迎元旦的电视盛会,是一场展现我国少数民族优秀艺术成就的庄严巡礼。2014年12月21日,由国家民委文化宣传司、中国文联国内联络部指导,中国电视艺术家协会、中国文学艺术基金会、四川广播电视台主办。

摘要：In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction *** Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation *** addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 ***,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 *** high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional *** trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.