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1.
Xinming Ren Beiyue Ma Gaofeng Fu Fan Qian Guoqi Liu Jingkun Yu Yawei Li 《Ceramics International》2021,47(14):19959-19969
The recycling of solid waste is a win-win solution for humans and nature. For this purpose, magnesite tailings and silicon kerf waste were employed to prepare MgO–Mg2SiO4 composite ceramics by solid-state reaction synthesis in the present work. Then, effects of sintering temperature and raw material ratio on as-prepared ceramics were systematically studied. As-prepared ceramics showed improvement in their relative density (from 47.55%–68.12% to 90.96%–95.25%) and cold compressive strength (from 7.34–118.66 MPa to 303.39–546.65 MPa) with the increase in sintering temperature from 1300 to 1600 °C. In addition, it was found that Si promoted synthesis process of Mg2SiO4 phase through transient liquid phase sintering and Fe2O3 accelerated sintering process through activation sintering. Consequently, the presence of Mg2SiO4 phase effectively improved the density and strength of MgO–Mg2SiO4 composite ceramic, while reducing its thermal conductivity. This work provides a potential reutilization strategy for magnesite tailings, and as-prepared products are expected to be applied in fields of construction, metallurgy, and chemical industry. 相似文献
2.
在第一部分综合讨论的基础上对甘三酯立体专一分析方法作了初步探讨。以液体油(菜油)及固体脂(猪脂)为基质,系统地研究了这一分析方法,取得了经验并补充了一些具体验证方法。分析液体油的结果与文献数据相一致,分析猪脂的结果欠佳,还存在一些问题需待进一步研究。 相似文献
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基于ANSYS Workbench的面齿轮传动固有特性分析 总被引:1,自引:1,他引:0
以正交面齿轮传动为研究对象,建立面齿轮传动的有限元模型,运用有限元软件A N S Y S Workbenck对该模型进行模态分析,提取该模型的前6阶固有频率和振型进行分析;并研究压力角、齿数差及面齿轮孔径对面齿轮传动固有频率的影响。研究结果表明:面齿轮传动的模态振型以面齿轮振动为主,面齿轮传动固有频率随压力角、齿数差及面齿轮孔径的增大而增大,其中面齿轮孔径对其影响最大,其次是压力角,而齿数差对其影响不大。 相似文献
6.
Sen Zeng Guoqi Ni Xiaojun Kuang 《Journal of Materials Science: Materials in Electronics》2016,27(10):10078-10081
High-Q dielectric materials ilmenite MgTiO3, columbite MgNb2O6 and cubic perovskite Ba3NiTa2O9 with negative temperature coefficient of resonant frequency (τ f ) were selected as candidates for compensating the τ f of hexagonal perovskite Ba8ZnTa6O24. X-ray diffraction data shows that Ba8ZnTa6O24 coexists with Ba3NiTa2O9 but is not compatible with MgTiO3 and MgNb2O6 at high temperature. The τ f for the mixed hexagonal/cubic perovskite Ba8ZnTa6O24–Ba3NiTa2O9 system is tunable via the temperature compensation effect and its quality factor may be improved via annealing the ceramics at high temperature to enhance the cation ordering in the cubic component. Permittivity ε r ~ 22–25, Q×f > 30,000 GHz and tunable τ f within ±10 ppm/°C were achieved in the range of about 50–80 wt% Ba3NiTa2O9 for the hexagonal/cubic perovskite composite Ba8ZnTa6O24–Ba3NiTa2O9 ceramics, which is suitable for the application as dielectric resonators and filters. 相似文献
7.
We propose a dynamic model for the evolution of an open animal population that is subject to an environmental catastrophe. The model incorporates a capture-recapture experiment often conducted for studying wildlife population, and enables inferences on the population size and possible effect of the catastrophe. A Bayesian approach is used to model unobserved quantities in the problem as latent variables and Markov chain Monte Carlo (MCMC) is used for posterior computation. Because the particular interrelationship between observed and latent variables negates the feasibility of standard MCMC methods, we propose a hybrid Monte Carlo approach that integrates a Gibbs sampler with the strategies of sequential importance sampling (SIS) and acceptance-rejection (AR) sampling for model estimation. We develop results on how to construct effective proposal densities for the SIS scheme. The approach is illustrated through a simulation study, and is applied to data from a mountain pygmy possum (Burramys Parvus) population that was affected by a bushfire. 相似文献
8.
某热电厂一期锅炉为WGZ220/9.8-4型锅炉,设计燃用贫煤,为解决供热问题,二期扩建3台WGZ220/9.8-13型锅炉,燃用低硫烟煤.本文从设计、运行安全上对一期锅炉改烧烟煤进行了可行性论证,并提出必须进行燃烧调整和对燃烧器及相应系统进行改造的建议. 相似文献
9.
在线接触摩擦副中,非光滑结构单元的凹坑、凸包、波纹、鳞片形态等表面凹坑形貌对其耐磨性有一定的影响,其中凹坑的直径、深度对耐磨性的影响十分显著。以圆形凹坑非光滑形貌为例,采用有限元仿真分析的方法,对非光滑表面凹坑不同直径和深度的磨损过程进行了分析,研究了仿生非光滑表面对摩擦副耐磨性影响的程度。研究结果表明:线性摩擦副工作过程中,凹坑间距为1 000 m的条件下,摩擦副表面的等效应力和摩擦力随着圆形凹坑直径的增大而增大,随其深度的增大而呈抛物线增长;且在凹坑直径为100 m、深度为300 m时,矩形块的耐磨性最优。 相似文献
10.
Ziyang Zhang Tianran Li Yujie Wu Yinjun Jia Congwei Tan Xintong Xu Guanrui Wang Juan Lv Wei Zhang Yuhan He Jing Pei Cheng Ma Guoqi Li Haizheng Xu Luping Shi Hailin Peng Huanglong Li 《Advanced materials (Deerfield Beach, Fla.)》2019,31(3)
Concomitance of diverse synaptic plasticity across different timescales produces complex cognitive processes. To achieve comparable cognitive complexity in memristive neuromorphic systems, devices that are capable of emulating short‐term (STP) and long‐term plasticity (LTP) concomitantly are essential. In existing memristors, however, STP and LTP can only be induced selectively because of the inability to be decoupled using different loci and mechanisms. In this work, the first demonstration of truly concomitant STP and LTP is reported in a three‐terminal memristor that uses independent physical phenomena to represent each form of plasticity. The emerging layered material Bi2O2Se is used for memristors for the first time, opening up the prospects for ultrathin, high‐speed, and low‐power neuromorphic devices. The concerted action of STP and LTP allows full‐range modulation of the transient synaptic efficacy, from depression to facilitation, by stimulus frequency or intensity, providing a versatile device platform for neuromorphic function implementation. A heuristic recurrent neural circuitry model is developed to simulate the intricate “sleep–wake cycle autoregulation” process, in which the concomitance of STP and LTP is posited as a key factor in enabling this neural homeostasis. This work sheds new light on the development of generic memristor platforms for highly dynamic neuromorphic computing. 相似文献