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排序方式: 共有651条查询结果,搜索用时 15 毫秒
121.
In the product of carbon made from tar oil by plasma pyrogenation, some nanowires, whose diameter is 9~20 nm and whose length is 300 nm were found. The result of X-ray Energy Dispersed Spectrum (EDS) indicated that it is a new compound K2Ti8O15, which has never been reported before. Compared with the corresponding stoichiometry compound K2Ti8O15, it is a non-stoichiometry compound in which two oxygen atoms are absent. It is due to the fact that the intensive deoxidization occured in the experimental process and the valence of titalium is alterable. Its microstructure in detail by high revolution electromicroscopy (HREM) and X-ray diffraction were studied. 相似文献
122.
本文介绍了网络控制系统的基本概念,分析了网络控制系统的优缺点,并主要针对网路控制系统中的时延问题,论述了6种时延网络控制系统控制方法:增广状态离散时间模型法、缓冲队列法、摄动法、随机最优控制方法、鲁棒控制方法、模糊逻辑调节法.本文对6种控制方法各自的特点和适用范围进行了较为详细地讨论,并对各自的优缺点进行了对比分析,对进一步研究适合于时延网络控制系统自身特点的控制方法进行了展望.本文研究的内容是当今控制领域研究的热点问题之一,无论对网络控制系统的研究与应用,还是对网络控制系统中时延问题的解决都具有一定的意义和参考价值. 相似文献
123.
针对基本麻雀搜索算法(Sparrow Search Algorithm, SSA)在迭代寻优过程中,种群多样性减少、易陷入局部极值等问题,提出一种改进的麻雀搜索算法(WSSA)。首先,基于Tent混沌映射策略初始化种群,提高初始解的质量;其次,结合鲸鱼优化算法(WOA)中的鲸鱼泡泡网捕食数学模型,改进发现者的位置更新策略,增强算法全局搜索;然后,采用自适应t分布变异,提升算法跳出局部最优能力;最后,在仿真实验中,结果表明改进麻雀搜索算法具有更好的收敛性和求解精度。 相似文献
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125.
Tingjunhong Ni Zichao Ding Fei Xie Yumeng Hao Junhe Bao Jingxiang Zhang Shichong Yu Yuanying Jiang Dazhi Zhang 《Molecules (Basel, Switzerland)》2022,27(11)
A series of triazole derivatives containing phenylethynyl pyrazole moiety as side chain were designed, synthesized, and most of them exhibited good in vitro antifungal activities. Especially, compounds 5k and 6c showed excellent in vitro activities against C. albicans (MIC = 0.125, 0.0625 μg/mL), C. neoformans (MIC = 0.125, 0.0625 μg/mL), and A. fumigatus (MIC = 8.0, 4.0 μg/mL). Compound 6c also exerted superior activity to compound 5k and fluconazole in inhibiting hyphae growth of C. albicans and inhibiting drug-resistant strains of C. albicans, and it could reduce fungal burdens in mice kidney at a dosage of 1.0 mg/kg. An in vivo efficacy evaluation indicated that 6c could effectively protect mice models from C. albicans infection at doses of 0.5, 1.0, and 2.0 mg/kg. These results suggested that compound 6c deserves further investigation. 相似文献
126.
Seungjin Yu Huiyan Piao N. Sanoj Rejinold Hanna Lee Goeun Choi Jin-Ho Choy 《Molecules (Basel, Switzerland)》2022,27(19)
Although nicotinic acid (NA) has several clinical benefits, its potency cannot be fully utilized due to several undesirable side effects, including cutaneous flushing, GIT-associated symptoms, etc. To overcome such issues and improve the NA efficacy, a new inorganic–organic nanohybrids system was rationally designed. For making such a hybrid system, NA was intercalated into LDH through a coprecipitation technique and then coated with Eudragit® S100 to make the final drug delivery system called Eudragit® S100-coated NA-LDH. The as-made drug delivery system not only improved the NA release profile but also exhibited good bio-compatibility as tested on L929 cells. Such an inorganic–organic nanohybrid drug delivery agent is expected to reduce the undesirable side effects associated with NA and hopefully improve the pharmacological effects without inducing any undesirable toxicity. 相似文献
127.
This paper investigates superconvergence properties of the local discontinuous Galerkin methods with generalized alternating fluxes for one-dimensional linear convection-diffusion equations. By the technique of constructing some special correction functions, we prove the(2k + 1)-th-order superconvergence for the cell averages, and the numerical traces in the discrete L~2 norm. In addition, superconvergence of orders k + 2 and k + 1 is obtained for the error and its derivative at generalized Radau points. All the theoretical findings are confirmed by numerical experiments. 相似文献
128.
最近研究表明利用环境噪声的互相关可以恢复两点之间的时域格林函数(声脉冲响应),这一原理在文献中被称为格林函数恢复。基于此原理,通过对多个传声器所接收的环境噪声进行互相关处理,获取与散射体相关联的散射波的到达时延信息,结合最小二乘反演算法和改进克希霍夫移位算法,分别获得道路交通噪声场中石柱以及海浪噪声场中塑料桶的空间位置,且其估计结果与实际测量相一致。实验结果表明将环境噪声作为探测信号进行散射体无源成像是可行的。这为设计室内无源声监测系统以及通过海洋环境噪声实现对水中静默目标成像提供了新思路和有益参考。 相似文献
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130.
为使磁约束聚变堆实现能量放大与氚自持,在其等离子体区周围设置次临界包层和产氚包层。采用天然铀合金燃料、轻水作冷却剂兼慢化剂,内嵌压力管式的次临界包层设计方案,通过对包层物理性能、结构概念设计、热工水力性能和安全分析,表明该方案可将聚变能量放大10倍以上,氚增殖比大于1.15,具有天然的临界安全性和良好余热安全性能。立足于近中期可利用的聚变技术,力争实现聚变能源的提前商用,为我国能源可持续发展提供一种有竞争力的技术选项。 相似文献