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41.
介绍了物联网的基本概念、核心技术以及在物联网背景下智能家居行业的发展与应用。智能家居利用物联网的网络通信技术、自动控制技术、音视频技术等对住宅内的家用电器、灯光照明进行智能控制,并结合其他系统为用户提供一个温馨舒适、安全节能的家居环境,让用户在生活中充分享受更多的方便与精彩。 相似文献
42.
利用数学极值理论分析了管道无压流最大过流量、最大流速的发生工况,并建立了最大过流量、最大流速与管线纵坡、管径、管道糙率的关系表达式,为管道设计提供参考和依据。 相似文献
43.
在μC/OS-Ⅱ的内存管理中,内存被分成多个内存分区,每个分区又包含整数个大小固定的内存块,且释放时必须回到所属分区。缺少灵活性,容易产生内存碎片,内存利用率不高。利用Tertiary Buddy System算法,将可用内存划分为2K和3×2K。增加了可选择的内存块大小数目及种类。提高了μC/OS-Ⅱ中内存的使用率,同时在灵活性和可靠性上有了很大提高。 相似文献
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《International Journal of Hydrogen Energy》2019,44(23):11675-11683
The development of cost-effective heterogeneous catalysts for the dehydrogenation of formic acid (FA) is the key challenge for the commercialization of FA as a hydrogen-storage medium. Herein, PdCoNi nanoparticles (NPs) with different element ratios supported on N-doped carbon nanosheets (N-CN) were designed, which exhibit excellent catalytic dehydrogenation performance for FA. Compared with PdCoNi NPs loaded on the carbon nanosheets (CN), the introduction of pyrrolic N to CN induces the formation of ultrafine, monodispersed and amorphous Pd0.6Co0.2Ni0.2 NPs with a size of 1.60 nm, which significantly increases the number of active sites and the instant contact between FA and catalysts. The as-prepared Pd0.6Co0.2Ni0.2/N-CN catalyst shows more than 99% conversion and 100% H2 selectivity at room temperature, with a record-high initial turnover frequency (TOFinitial) of 1249.0 h−1 among non-noble containing Pd-based catalysts, which demonstrates the high potential of Pd0.6Co0.2Ni0.2/N-CN as a practical catalyst for the hydrogen generation from FA. 相似文献
47.
The present study aimed to measure the retention of aroma compounds (ethyl acetate, ethyl hexanoate and carvacrol) in dispersions based on konjac glucomannan and/or potato starch, and to highlight the influence of konjac glucomannan on the mechanisms involved in aroma retention. Publications on the effect of konjac glucomannan on aroma release are scarce. Konjac glucomannan is a polysaccharide used as a food additive for its viscous and emulsifying properties. Retention of aroma compounds in dispersions was calculated from partition coefficients which were measured using the phase ratio variation method. This method, consisting of analyses of the headspace at equilibrium, enables the determination of the partition coefficient of volatile compounds in a gas/liquid system without external or internal calibration. The three aroma compounds chosen for this study behave differently toward amylose. Prior to the release study, the complexing behavior of carvacrol with starch, hitherto unknown, was investigated by X-ray diffraction: V6III amylose complexes were formed with carvacrol. Our results showed no specific interaction between ethyl hexanoate and potato starch or konjac glucomannan. Ethyl acetate retention seemed to be due to trapping in the complex network of polysaccharides and to the density of this network. Retention of carvacrol was influenced by the nature of polysaccharides present in the dispersion, and was mainly governed by specific interaction with starch. Additionally, the addition of konjac glucomannan to potato starch dispersions decreased the retention of volatile compounds complexing starch, but had little effect on the retention of the other aroma compounds. 相似文献
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Microsystem Technologies - Efficient and accurate path planning in a complex biological environment have become a challenge for nanorobot research. This paper first reviews the current path... 相似文献
49.
《International Journal of Hydrogen Energy》2019,44(54):28984-28995
We simulate agglomeration in different fuel cell catalyst ink solutions using Discrete Element Method. Carbon support is modelled as particles in various inks with ionomer and various solvents. The particles interact with particle-pair forces resulting in agglomerate build-up. The classical colloidal theory with van der Waals and electric double layer forces underestimates the ink stability, which motivates the development of a new model of polymer force between particles. The force is activated when there is a bridging of polymer between the carbon black particles, and the strength is dependent on the ionomer interaction with the solvent by the dielectric constant. A critical dielectric constant was defined for which ionomer form a web-like polymer network that increases the ink stability. This modification can explain the trend of the ink stability, and the model can simulate the effect of different solvents on the agglomerate size distribution with good agreement with experimental results. 相似文献
50.
大型整体式修边模的堆焊是以普通铸铁为基体,通过选用新型堆焊焊条在模具刃口部位堆焊,替代传统的、采用镶拼修边刃块的修边模制造大型整体式修边模的工艺。通过实践和总结,得出了合理的堆焊工艺参数和预防焊接缺陷的具体措施。实践表明,堆焊刃口的组织和硬度均满足使用要求,具有生产效率高、经济耐用的特点,明显优于传统镶拼修边刃块的制造工艺,特别适用于改型车的模具开发与制造。 相似文献