基于真实问题情境的化学活动课设计*——以“氧化铁与酸的反应”为例

基于联系生活实际的真实问题情境,设计化学活动课,让学生在探究“可乐可以除铁锈”本质原因的过程中学习“氧化铁与酸的反应”,从而发展化学学科核心素养,提高解决实际问题的能力。     

Review of cavity optomechanical cooling

Quantum manipulation of macroscopic mechanical systems is of great interest in both fundamental physics and ap- plications ranging from high-precision metrology to quantum information processing. For these purposes, a crucial step is to cool the mechanical system to its quantum ground state. In this review, we focus on the cavity optomechanical cooling, which exploits the cavity enhanced interaction between optical field and mechanical motion to reduce the thermal noise. Recent remarkable theoretical and experimental efforts in this field have taken a major step forward in preparing the mo- tional quantum ground state of mesoscopic mechanical systems. This review first describes the quantum theory of cavity optomechanical cooling, including quantum noise approach and covariance approach; then, the up-to-date experimental progresses are introduced. Finally, new cooling approaches are discussed along the directions of cooling in the strong coupling regime and cooling beyond the resolved sideband limit.     

BaCo0.7Fe0.2Nb0.1O3-δ膜反应器还原侧表面反应机理

研究了BaCo0.7Fe0.2Nb0.1O3-δ(BCFN)透氧膜反应器还原侧表面反应机理, 分析了表面催化微粒及催化床对膜反应器的作用. 提出了“催化解离机制”是构成甲烷重整BCFN膜反应器透氧量上升的主要原因; CH4, H2及CO在BCFN膜表面的反应活性依次为H2>CO>CH4; 当CH4气氛中加入H2或CO时, BCFN膜表面的主要发生由CH4直接氧化转变H2或CO的氧化反应, 同时极大提升了BCFN膜反应器的透氧量; BCFN膜表面氧化反应为“晶格氧”氧化反应模式主导.     

Total colorings of planar graphs without adjacent triangles

Let G be a planar graph without adjacent 3-cycles, that is, two cycles of length 3 are not incident with a common edge. In this paper, it is proved that the total coloring conjecture is true for G; moreover, if Δ(G)≥9, then the total chromatic number χ^″(G) of G is Δ(G)+1. Some other related results are obtained, too.     

Etching effect of the autocloning structure using ion-assisted deposition

Based on the autocloning technique the photonic crystals were fabricated using E-beam gun evaporation with ion-assisted deposition (IAD) on the periodic corrugation patterns of substrates. In this research, the surface evolution function based on the unified process model was simulated to analyze the influence of the etching and redeposition effects of the different etching time. As the etching time was longer, the top roof angle was larger and the redeposition thickness was getting thicker. The difference of the top roof angle in the experiment and the simulated result are less than 4°. It shows the simulation method achieved very good agreement with the fabricated result for different etching times from 40 to 120 min. We found the surface angular was depended on the etching effect more than the redeposition effect.     

中速C3+与Ne原子靶相互作用过程中单电子转移绝对截面的测量

实验测量了2.2v₀—4.2v₀(v₀为玻尔速度,v₀=2.19×10⁸cm/s)的C³⁺与Ne原子碰撞过程中单电子转移绝对截面.将实验结果与多体经典轨道蒙特卡罗模拟计算结果进行了比较.用电离能的变化、屏蔽效应、动态关联对实验和理论计算结果间的数值差异做了分析.总体上,实验结果与多体经典轨道蒙特卡罗方法计算结果在趋势上相 关键词： 离子-原子碰撞 单电子转移 绝对截面     

八面沸石超笼内卟啉钴（Ⅱ）的合成与表征

80年代初期Norman Herron及他的同事将酞菁铁镶嵌在X、Y型分子筛超笼内,可使酞菁的寿命增长并具有选择性催化作用。卟啉与酞菁的结构类似,有些卟啉催化性能虽好,但稳定性不高,如果将卟啉镶嵌在分子筛超笼内,可能会提高卟啉的稳定性,并改变它的催化性能。开展这一工作可为寻找新型催化剂开辟一条新途径。本文首次将四卤甲基卟啉(TCTMP,TBTMP)镶嵌在NaX分子筛超笼内。通过UV-Vis、IR、SEM和吸附等手段予以表征。     

A low cost and simple configuration of multifunctional multichannel analyzer based on a personal computer

A low cost and simple configuration of multifunctional MCA based on a personal computer is described. It can be used as a spectrum multiscaling analyzer, multi-input pulse height analyzer and dual parameter MCA. It can also be used in a master-slave ADC configuration in order to cut down the dead time of the system. All the functions can be performed by loading the corresponding programs without altering the hardware configuration. Interrupt service routines are used to handle the digital data converted by ADC. A dead time counter is also provided to record the dead time profile by measuring the ADC busy time.     

Fischer-tropsch synthesis over ruthenium/Y-zeolite catalysts: Effects of the neutralizing cations of zeolites

The effect of steaming on HZSM 5 has been characterized by using two model reactions: n-heptane cracking and m-xylene isomerization. For both reactions, the activity of HZSM 5 was increased by steaming at low water vapor pressure, but at a high pressure it became lower than that of the non-steamed sample. Modifications in the acidity and a slight blockage of the pores by extralattice aluminium can explain this behavior.

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