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81.
为了给光锥与时间延迟积分电荷耦合器件耦合监控装置提供有效的被测运动条纹,分析了传统推扫成像实验装置的不足之处,设计了电子显示目标滚屏运动装置.采用光学相机对印刷条纹静止成像,并用TDI-CCD数字相机对监视器屏幕上的运动条纹动态成像.实验结果表明,该方案解决了高分辨率的鉴别率图样无法在监视器或投影仪上精确显示的困难.与传统的实验室模拟装置相比,该方案提高了鉴别率条纹的运动稳定性,减小了条纹运动速率与TDI-CCD扫描行频间的失配误差,不仅能够对耦合过程实施监控,而且还能用于耦合系统的像质评价. 相似文献
82.
83.
Yongjin Fang Bu Yuan Guan Deyan Luan Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7821-7825
Metal sulfides have received considerable attention for efficient sodium storage owing to their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium‐ion batteries. Herein, an elegant multi‐step templating strategy has been developed to rationally synthesize hierarchical double‐shelled nanoboxes with the CoS2 nanosheet‐constructed outer shell supported on the CuS inner shell. Their structure and composition enable these hierarchical CuS@CoS2 nanoboxes to show boosted electrochemical properties with high capacity, outstanding rate capability, and long cycle life. 相似文献
84.
Ya‐Pan Wu Jun‐Wu Tian Shan Liu Bo Li Jun Zhao Lu‐Fang Ma Dong‐Sheng Li Ya‐Qian Lan Xianhui Bu 《Angewandte Chemie (International ed. in English)》2019,58(35):12185-12189
Embedding cubane [M4(OH)4] (M=Ni, Co) clusters within the matrix of metal–organic frameworks (MOFs) is a strategy to develop materials with unprecedented synergistic properties. Herein, a new material type based on the pore‐space partition of the cubic primitive minimal‐surface net (MOF‐14‐type) has been realized. CTGU‐15 made from the [Ni4(OH)4] cluster not only has very high BET surface area (3537 m2 g?1), but also exhibits bi‐microporous features with well‐defined micropores at 0.86 nm and 1.51 nm. Furthermore, CTGU‐15 is stable even under high pH (0.1 m KOH), making it well suited for methanol oxidation in basic medium. The optimal hybrid catalyst KB&CTGU‐15 (1:2) made from ketjen black (KB) and CTGU‐15 exhibits an outstanding performance with a high mass specific peak current of 527 mA mg?1 and excellent peak current density (29.8 mA cm?2) at low potential (0.6 V). The isostructural cobalt structure (CTGU‐16) has also been synthesized, further expanding the application potential of this material type. 相似文献
85.
冠状病毒是一类广泛存在且对人及家畜具有严重危害的病原体,其中于2003年全球爆发的严重急性呼吸综合征病毒(SARS-CoV)以及2012年被发现并传播的中东呼吸综合征病毒(MERS-CoV)给人们的生命健康以及全球经济造成了严重威胁以及重大损失,特别是2019年末爆发的新型冠状病毒(SARS-CoV-2),截至目前为止已经造成了几百万的感染病例以及几十万人的死亡。可以看出,冠状病毒具有较高的传播性以及较高的致死率,时刻威胁着人们的健康安全,但是针对冠状病毒的感染目前还没有批准上市的有效药物,也没有用于预防的疫苗。本文围绕目前关于冠状病毒的潜在成药性靶点,详细介绍了针对这些靶点的具有代表性的抑制剂的结构设计及其化学合成方法,以期为目前抗冠状病毒药物的研发提供一些参考。 相似文献
86.
以电位滴定终点确定新方法探讨研究为例,从5个方面介绍将创新能力培养融入基础课教学的探索。通过该研究提高了学生基础课学习热情与学习质量。首先改进了二次差值微商终点计算方法,通过Excel 计算Δ2E/ΔV-V 二次差值微商法数据表中的最高点与最低点直线线性方程 y=ax+b,令 y=0, x=-b/a即为终点。另外,研究得到了模拟滴定曲线微分法确定电位滴定终点的新方法。用Excel 对滴定曲线进行三次方程模拟即:y=ax3+bx2+cx+d,二次微分后得到: d2y/dx2=6ax+2b, 当d2y/dx2=0,对应的x=-b/3a处即为滴定终点。2 相似文献
87.
88.
Jiqing Xu Renzhang Wang Chunxiao Guo Guoyu Yang Qingxin Zeng Weiming Bu Ling Ye Yuguo Fan Guangdi Yang 《中国科学B辑(英文版)》2001,44(2):137-146
A nickel-1,10-phenanthroline complex supported on an octamolybdate, [(Ni(phen)2
2(ξ-Mo8O26)], has been hydrothermally synthesized with MoO3, H2MoO4, Ni(OAc)2 6H3O and 1,10-phenathroline (1,10-phen) as raw materials. The crystals of the compound belong to monoclinic P21/n space group,a = 1.2952(2),b = 1.6659(10),c = 1.3956(12) nm, β =106.273(8)°,V = 2.8906(5) nm3,Z = 2. 5604 observable reflections (I >2σ(I)) were used for structure resolution and refinements to converge to finalR
1 = 0.0414,wR
2 = 0.0815. The result of structure determination shows that the compound contains octamolybdate possessing a novel structure
type (named as ξ-isomer). The feature of ξ-[Mo8O26]4- is that it is composed of Mo6O6 ring and two MoO6 octahedral located at cap positions on opposite faces. The Mo6O6 ring contains two octahedral and four trigonal-bipyramidal MoVI atoms. Each ξ-[Mo8O26]4- unit is bonded with two [Ni(phen)2]2+ through terminal oxygen atoms of octahedral and neighbouring trigonal-bipyramidal Mo atom in the Mo6O6 ring. IR and UV-Vis spectra of the compound were measured and its electronic structure was studied by EHMO method. 相似文献
89.
Hongfang Yang Dr. Li Han Jing Zhao Prof. Dr. Xinyu Song Prof. Dr. Qisheng Song Prof. Dr. Yuxiang Bu 《Chemphyschem》2012,13(18):4148-4154
Graphene oxide has attracted intense research interest recently because the graphene oxide synthesis route, as a promising alternative for cost‐effective mass production of graphene, has been explored. To further study the oxidation process and possible mechanism and to explore applicability of the oxidized products, we have performed a computational study on three series of oligoacene dioxides, focusing on their structures and electronic properties. Taking 1,5‐dioxidized naphthalene as a starting point, three series of oligoacene dioxides are considered as follows: 1) middle insertion by 1–2 benzene rings; 2) single‐side expansion using 1–2 benzene rings; 3) double‐side expansion using two benzene rings. On the basis of density functional theory and complete active space self‐consistent field (CASSCF) calculations, we reveal that oligoacene dioxides in the middle insertion series have a triplet ground state, whereas those in the single‐side expansion series and the double‐side expansion series have open‐shell broken‐symmetry singlet diradical ground states except for their common origin naphthalene‐1,5‐dioxide whose ground state is triplet and which is also viewed as the origin of the middle insertion series. Magnetic coupling interactions of these oligoacene dioxides are also determined. This work should help people toward an atomistic understanding of the electronic structures and properties of possible intermediates or products and even the oxidation mechanism of graphene sheets, and provides a reasonable strategy of designing novel graphene‐oxide‐based magnetic materials. 相似文献
90.
Jiaoran Meng Xiaodong Zhang Hao Wu Jing Bu Chenyi Shi Chunhui Deng Yu Mao 《Analytica chimica acta》2012
Conditioned place preference (CPP) is a widely used model to explore the mechanism of context-dependent learning. In this work, we developed a GC–MS method to investigate the metabolites in mice brain which was used to study the mechanism of context-dependent learning associated with rewarding effect of morphine. Metabolites were extracted from brain tissues and derivatized followed by analysis by gas chromatography/mass spectrometry (GC–MS). In total, 69 peaks were identified as known compounds. By a Wilcoxon ran sum test with p value ≤0.05, 21 metabolites were selected and considered as the potential biomarkers of morphine in mice brain. Using principal component analysis (PCA) and receiver-operator characteristic (ROC) curves, a model was constructed with a combination of these 21 metabolic markers. Multivariate statistics of the model yielded separation between the two groups with an area under the curve value of 0.947. Some metabolites were further discussed in detail about their pathway. Results showed that our technique can be successfully applied to profile for biomarkers and in understanding molecular mechanisms of drug abuse. 相似文献