大学物理实验中用坐标纸作图的规范性

大学物理实验中,作图法是数据处理中比较重要的一种方法,用坐标纸作图是数据处理训练的必要途径,但目前不少学生手工作图并不规范。总结出作图法的6条基本规则,并通过实验数据作图的实例,分析学生较为常见的手工作图不规范表现,并提出相应的教学建议。     

Dynamic and static nature of activated interactions in transition states as elucidated by quantum theory of atoms-in-molecules dual functional analysis: A case of ligand exchange at the N of sulfonylimino-λ3-bromanes

A method to elucidate the dynamic and static natures of the activated interactions in transition states (TSs) is proposed using quantum theory of atoms-in-molecules (QTAIM) dual functional analysis (QTAIM-DFA). The natures are determined for the ligand exchange at the N of sulfonylimino-λ³-bromanes, RBr-*-N(SO₂CF₃)-*-X′R′ (R, R′ = Me or Ph, X′ = Br′ or I′). Asterisks (*) emphasize the presence of bond critical points within the interactions in question. While data from the optimized structures of TSs correspond to the static nature, those from the perturbed and optimized structures represent the dynamic nature. The nature of the interactions in Br-*-N-*-X′ calculated with QTAIM-DFA, using the perturbed structures generated using the normal coordinates for the imaginary frequencies (NIV), was very similar to that in trigonal bipyramidal adduct formation through charge transfer. The results with NIV were precisely the same as those obtained based on intrinsic reaction coordinate (IRC). The high applicability of QTAIM-DFA is demonstrated when analyzing the activated interactions in TSs.     

基于不动点计算的岸线动态分析方法

现有地理信息系统对于海岸线这一独特线对象的动态变化缺乏有效的管理和分析手段。针对该问题,该文引入不动点的概念,基于现有地理信息系统设计了一种基于不动点计算的岸线动态分析方法,达到分析海岸淤进或蚀退动态变化的目的,进而实现岸线动态变化的自动分析功能。文章对真实的黄河口岸线数据进行了实验分析,证明了基于不动点计算的岸线动态分析方法的有效性。     

环形掺Er3+光纤激光器输出特性分析与实验研究

理论分析了掺Er^3＋光纤环形腔激光器的输出特性,获得了稳态条件下激光器输出功率、阔值泵浦功率和斜率效率的解析表达式．分析了泵浦光波长、泵浦功率、Er^3＋光纤掺杂浓度、输出端耦合器分光比等的影响,推导了在特定输出波长处获得最大输出功率所需最佳掺Er^3＋光纤长度的解析表达式。进行了LD泵浦掺Er^3＋光纤环形腔激光器的实验工作,获得了斜率效率10％以上的激光输出。     

某些电荷转移反应中线性反应坐标确定的反应途径的非唯一性

在电子转移半经典模型的基础上,对氟代苯并菲组成的盘状液晶体系的电荷转移反应进行了研究,其反应动力学参数在量子化学B3LYP/6-31G(d,p)水平进行计算.研究中发现在反应物和产物的构型确定后,用线性反应坐标构造的反应途径和过渡态的构型不是唯一的.其原因是反应物和产物确定后,其独立内坐标的选择并不是唯一的.因此在计算电荷转移速率常数时必须考虑到多个过渡态构型才能得到定性正确的结果.     

对甲苯磺酸三乙铵作为气相色谱固定相测定酱油中的苯甲酸

苯甲酸具有杀灭或抑制微生物繁殖的作用,其作为食品防腐剂,被广泛用于酱油、罐头、酱菜以及饮料等食品中。但摄入过量的苯甲酸会影响人体的肝脏功能,对人体产生危害,因此食品中苯甲酸的测定一直受到人们的关注。用于测定食品中苯甲酸的气相色谱固定相有许多,比如SE-30[1]、DEGS     

对甲苯磺酸三甲胺固定相的研究及其分析应用

采用汞塞动态法涂柱,以对甲苯磺酸三甲胺作为固定液制备了石英毛细管色谱柱,固定液量为9.0%(m/V),柱尺寸为30 m×0.32 mm i.d.。对该柱的性能进行了考察。实验结果表明,这种色谱固定相对于极性有机化合物如醇类物质、有机羧酸、酚类物质等有良好的分离能力,且出峰快,时间短,峰形窄而对称。     

对自由落体的诺维科夫时间与牛顿绝对时间关系讨论

文章首先将史瓦西黑洞场中自由下落质点的固有时(诺维科夫坐标时)公式,由自然单位制化成了国际单位制中的形式.然后,根据牛顿第二定律和万有引力定律,推导出了自由下落质点经历的绝对时间公式,进而证明了广义相对论中自由落体经历的固有时,恰好等于牛顿力学给出的绝对时间.最后,对自由下落质点在黑洞内外经历的时间进行了特例计算.     

Synthesis and Crystal Structure of Complex [Pb(qina)2(DMSO)]·H2O

A novel complex [Pb(qina)2(DMSO)]·H2O was synthesized, of which qina- is the quinaldic acid radical and DMSO the dimethyl sulfoxide. Elemental analysis, IR spectra, and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. This complex belongs to monoclinic system, space group P121/n1, with a = 7.1553(17), b = 17.543(2), c = 17.306(2)(A),β = 91.671(4)°, C22H20N2O6PbS, Mr = 647.65, Z = 4, V= 2171.5(6)(A)3, Dc= 1.981g/cm3,μ = 7.908 mm-1, F(000) = 1248, -9≤h≤6, -23≤k≤ 19, -22≤l≤22, R= 0.0221 and wR =0.0488. Weak coordinate bond is formed between oxygen atom in DMSO and Pb(Ⅱ ). There are also weak interactions, such as π-π interaction, hydrogen bonds and so on, among the complex molecules.     

Synthesis and Crystal Structure of a 1D Chained Coordination Polymer Containing One-dimensional Egg-like Channels： {[Cu2（C2O4）2（inta）4]（inta）}n （inta = Isonicotinamide）

A new one-dimensional copper coordination polymer chain has been prepared and fully characterized by single-crystal X-ray diffraction,elemental analyses and IR spectroscopy. The compound {[Cu2(C2O4)2(inta)4](inta)}n1 crystallizes in the triclinic system,space group P1,with a=8.4722(5),b=10.9825(6),c=11.6128(6),α=104.8050(10),β=102.5740(10),γ= 109.6890(10)o,V=927.18(9)3,Mr=929.79,Z=1,Dc=1.665 g/cm3,F(000)=475,μ=1.231 mm-1,R=0.0453 and wR=0.1185 for 3290 observed reflections (I > 2σ(I)). Of the compound,the Cu center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the copper atom and each inta serving as a terminal ligand by employing only one N-donor to coordinate with the Cu center. An infinite {Cu2(C2O4)2}∞ chain is formed along the c axis. Furthermore,the 1D chains are held together via extensive hydrogen-bonding interactions to generate a three-dimensional network with 1D channels (ca. 5.491×11.507) where inta molecules are filled.