排序方式： 共有13条查询结果，搜索用时 21 毫秒
1.
研究了一种基于STC12C5A60S2单片机的智能测角仪。该测角仪由加速度传感器模决MMA7455、时钟模块DS1302、温湿度模块DHT11、语音模块ISD4004组成,实现了角度、时间、温湿度的显示、存储以及语音播报的功能,具有一定的推广价值和实用性。 相似文献
2.
文章主要在实验室条件下对废旧有机玻璃裂解所制得甲基丙烯酸甲酯粗产品的纯化方法进行研究.研究了粗产品中分别加入氯化钙、氯化镁后对甲醇杂质含量以及添加量和作用时间对效果的影响情况.实验结果表明,加入氯化钙时,每25 ml甲基丙烯酸甲酯粗单体中加入1.0 g氯化钙、放置4 h后甲醇含量降至最少;加入氯化镁时,每25 ml甲基丙烯酸甲酯粗单体中加入0.5 g氯化镁、放置1 h后甲醇含量降至最少. 相似文献
3.
A novel iron-ytterbium dinuclear catalyst, FcB(MeCp) Yb (MeCp) Cl (Fc: ferrocenyl, B: diethylene ether), was synthesized for
the polymerization of methyl methacrylate (MMA). Synergistic effects between the ferrocenyl group and the lanthanocene part
were investigated regarding their catalytic behaviors. UV, IR, GPC and NMR were used to characterize the structures of the
catalyst and polymer. Kinetic study showed that polymerization is first order in monomer concentration and fractional order
(0.78) in the catalyst. The bimetallic complex is a good catalyst for the polymerization of MMA, giving high molecular weight
PMMA with 78% syndiotactivity.
Project (29774021) supported by NSFC and Laboratory of Rare-Earth Chemistry and Physics, Changchun Institute of Applied Chemistry,
Chinese Academy of Sciences 相似文献
4.
SBS接枝共聚的研究 总被引：1，自引：0，他引：1
王红明 《广东教育学院学报》2003,23(2):41-43
研究MMA与SBS的接枝共聚反应，合成了主链为SBS，支链为PMMA的接枝共聚物；其结构巳被红外光谱分析所证实． 相似文献
5.
本文采用问卷法、录像分析法、对比分析等研究方法,对散打和摔跋转型运动员在MMA比赛中的技术应用和获胜方式进行研究,分析他们的技术长处与存在不足,并提出相应改进建议,旨在为提高转型运动员综合实力、提高我国MMA运动技术水平提供参考。 相似文献
6.
常数模算法（constant modulus algorithm,CMA）能够很好地克服无线信道引入的符号间干扰（ISI）,在信道均衡中广泛应用,但存在稳态误差大,相位旋转的问题;MMA算法解决了CMA算法的相位旋转问题,但仍然有较大的稳态误差。为了克服以上缺点,在研究各种算法的基础上,引入非线性函数来构造步长调整参数,计算机仿真结果表明,相比传统算法,变步长盲均衡算法有较快的收敛速度和更好的均衡效果。 相似文献
7.
甲基丙烯酸甲酯是一种重要的有机化工原料,主要应用于生产有机玻璃及有机玻璃模塑料及其它工程塑料产品、PVC改性剂、胶粘剂、表面涂料等,市场前景十分广泛。 相似文献
8.
Drawing on qualitative interviews with Mixed martial arts (MMA) athletes and stakeholders, this study aims to investigate the relationship between, on the one hand, MMA as a spectacle and imaginary world, and on the other, the fighters’ experiences of violence, pain and ‘the real’. Analytically, we are influenced by the literature on the spectacle and on hyperreality. The results show that athletes’ negotiations concerning the sport largely connect to a particular way of approaching violence – culturally and in terms of physical experience. On the one hand, there is a desire to portray MMA as a civilized and regulated sport. The athletes develop different strategies by which to handle or renegotiate the physical force and violence in the cage. On the other hand, however, the fighters’ bodily control and management of their fear sometimes breaks down. When the spectacle of the octagon becomes ‘real’, the legitimacy of the sport is questioned. 相似文献
9.
Tóshiko Takahashi-I?iguez Enrique García-Hernandez Roberto Arreguín-Espinosa María Elena Flores 《Journal of Zhejiang University. Science. B》2012,13(6):423-437
Vitamin B12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM’s inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods. 相似文献
10.
赵平喜 《福建工程学院学报》2017,(5):447-451
综合搏击文化传播和认同具有重要意义,有利于推广人类非物质文化遗产;可以促进全球跨文化沟通和交流;有助于现代体育传播的发展壮大等。当前综合搏击文化在传播和认同过程中存在一些问题,如缺少正确引导,模式单一;遭遇本土传统文化壁垒;难以突破发展壮大的瓶颈等。因此有必要整合资源、正确引导综合搏击文化传播;构建多元体育文化认同体系;促进综合搏击文化创新,使综合搏击文化获得普及推广和健康发展。 相似文献