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91.
本文共分两部分,第一部分是研究最简气体动力学方程组较文献[6]更一般的始值问题,得出了解的大范围存在性及始值所具有的性质对时间t的不变性,并对解的性质进行了某些研究。在假设用(u0(±∞),v0(±∞))(u0(x),v0(x)表示始值)解黎曼问题时存在某一向激波的情形,证明了解必然包含一条某一向激波。应该指出,同向激波和稀疏波的相互作用是本文所研究的始值的一个特例。第二部分是把第一部分中所得的主要结果推广到文献[7]中研究过的方程组上去。 相似文献
92.
The effects of trapped electrons on off-axis lower hybrid current drive (LHCD) in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.[第一段] 相似文献
93.
一种新的氟离子荧光识别主体2,3-二(2-吡咯酰胺)甲基喹喔啉的合成、结构及离子识别研究 总被引:4,自引:3,他引:1
设计并合成了2,3-二(2-吡咯酰胺)甲基喹喔啉化合物2.通过X射线单晶衍射研究了该化合物的固态结构.分别利用荧光和紫外-可见光谱技术研究了其对阴离子的识别,发现化合物2能在DMSO中对氟离子进行有效的选择性识别,主要的识别位点为吡咯NH和酰胺NH. 相似文献
94.
A sea-air oscillator model is studied using the time delay theory. The aim is to find an asymptotic solving method for the El Nino-southern oscillation (ENSO) model. Employing the perturbed method, an asymptotic solution of the corresponding problem is obtained. Thus we can obtain the prognoses of the sea surface temperature (SST) anomaly and the related physical quantities. 相似文献
95.
Jin Xie Dr. Hong-Jie Peng Yun-Wei Song Dr. Bo-Quan Li Ye Xiao Meng Zhao Dr. Hong Yuan Prof. Jia-Qi Huang Prof. Qiang Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17823-17828
Use of redox mediators (RMs) is an effective strategy to enhance reaction kinetics of multi-electron sulfur electrochemistry. However, the soluble small-molecule RMs usually aggravate the internal shuttle and thus further reduce the battery efficiency and cyclability. A semi-immobilization strategy is now proposed for RM design to effectively regulate the sulfur electrochemistry while circumvent the inherent shuttle issue in a working battery. Small imide molecules as the model RMs were co-polymerized with moderate-chained polyether, rendering a semi-immobilized RM (PIPE) that is spatially restrained yet kinetically active. A small amount of PIPE (5 % in cathode) extended the cyclability of sulfur cathode from 37 to 190 cycles with 80 % capacity retention at 0.5 C. The semi-immobilization strategy helps to understand RM-assisted sulfur electrochemistry in alkali metal batteries and enlightens the chemical design of active additives for advanced electrochemical energy storage devices. 相似文献
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A sea—air oscillator model is studied using the time delay theory. The aim is to find an asymptotic solving method for the El Ni no-southern oscillation (ENSO) model. Employing the perturbed method, an asymptotic solution of the corresponding problem is obtained. Thus we can obtain the prognoses of the sea surface temperature (SST) anomaly and the related physical quantities. 相似文献
99.
A series of bisthienylethenes containing imidazole and imidazolium derivatives have been prepared and the products have been characterized by means of NMR and MS.Their photochromic and fluorescent switch properties have been investigated by UV–vis absorption spectra and fluorescence spectra.The fluorescent emissions of these kinds of photochromic compounds can be simply modulated by varying the imidazole groups,which shows that these compounds may have potential application in the design of fluorescent photochromic materials. 相似文献
100.