Molecular Spectra and Dissociation Dynamics of Oxalyl Chloride: Effect of External Electrical Fields

Oxalyl chloride is a highly toxic and caustic substance, which widely exists in human production and life as a kind of volatile organic compound. Based on the density functional theory B3 LYP at 6-311++G(d, p) level, the influences of external electric field on the bond length, bond energy, dipole moment and dissociation mechanism are optimized. The results indicate that the C_1–Cl_3 bond length increases while the C_4–Cl_6 bond decreases. At the same time, the carbon-carbon bond length gradually increases with the increase of electric field. The total energy decreases while the dipole moment gradually increases with the increase of electric field. In the infrared spectra, the vibration frequency of the carbon-chlorine(C_4–Cl_6) bond decreases while the vibration frequency of the carbon-oxygen bond increases. In the ultraviolet-visible spectra, the wavelength of the strongest absorption peak increases as the external electric field increases and shows an observable red shift phenomenon. Additionally, single point energies of oxalyl chloride along the carbon-carbon bond are scanned with the equation-of-motion coupled cluster method restricted to single and double excitations(EOM-CCSD) method and the potential energy curves under different external electric fields are obtained. The dissociation barrier in potential energy curve decreases because of the breakage of carbon-carbon bond with the increase of external electric field. These results provide reference for further researches on the properties of oxalyl chloride and offer a theoretical basis for the study of oxalyl chloride degradation.     

Understanding Chemical Reactivity in Extended Systems:Exploring Models of Chemical Softness in Carbon Nanotubes

Chemical reactivity towards electron transfer is captured by the Fukui function.However,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground states.In such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate states.Spatialpseudo-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended systems.Given the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited states.Here we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of states.The local softness is approximately equal to the density of states at the Fermi level.However,such approximation leaves out the contribution of inner states.In order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is presented.Single wall capped carbon nanotubes(SWCCNT) illustrate the limitation of the frontier orbital theory in extended systems.Thus,we have used a C360 SWCCNT to test the proposed model and how it compares with available models based on the local density of states.Interestingly,a simple Hü ckel approximation captures the main features of chemical response of these systems.Our results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.     

新型哌啶-查尔酮类衍生物的设计、合成及抗宫颈癌和逆转顺铂耐药活性

本文采用活性亚结构拼接原理,设计并合成了15个新型含哌啶的查尔酮类衍生物,利用¹H NMR、¹³C NMR和HR-MS对结构进行表征,并初步评价了其抗宫颈癌和抗顺铂耐药宫颈癌活性作用。结果表明,化合物6g具有一定的抗肿瘤活性和逆转顺铂耐药作用;并采用Elisa法、联合顺铂用药、Western Blot和分子对接对化合物6g与VEGFR-2和P-gp靶点进行了初步的研究。本研究为基于VEGFR-2和P-gp双靶点新型分子靶向查尔酮类衍生物的设计提供了一条思路。     

GSI 对最重的靶元素254Es 的首次轰击

在10月10—18日之间,在GSI,人们利用尤尼拉克(UNILAC)的束流对99号元素锒的同位素~(254)Es(半寿命T_(1/2)=276天)进行了首次轰击,这是迄今使用的最重的靶元素;该实验用了2μg 的Es 同位素,这几乎是世界上仅有的库存。实验是由劳伦斯利弗莫尔实验室和GSI 合作完成的,其目的是想用~(16)O,~(18)O和~(22)Ne 作炮弹对~(254)Es 进行轰击,找到生成丰中子重锕系元素和超锕系同位素的最佳反应条件。去年在利弗莫尔的离线化学实验表明,这个方法将被认为是这次实验的唯一有效的。     

Ag_(60)纳米颗粒[{Cl@Ag_(12)}@Ag_(48)(dppm)_(12)]的结构(其中dppm=双(二苯基膦基)甲烷)（英文）

本文合成一种新的双膦连接Ag_(60)纳米团簇[{Cl@Ag_(12)}@Ag_(48)(dppm)_(12)],并通过X射线晶体学进行表征.二十面体的银处于核心位置,里面是中心氯化物组成,外面有48个银原子/离子的包裹,顶端是12个双(二苯基膦基)甲烷(dppm)配体.同时利用密度泛函理论对阳离子[{Cl@Ag_(12)}@Ag_(48)(dppm)_(12)]~+进行计算,以确定该结构是否对应于核心数n=58的超原子.DFT计算的优化结构与X射线一致,但是HOMO-LUMO的能差并不能保证共超级稳定性.     

Brönsted酸性离子液体催化芳香醛和2-甲基喹啉反应合成1,3-二(2-喹啉基)丙烷化合物

以Brönsted酸性离子液体1-乙基-3-丁基咪唑对甲苯磺酸盐为催化剂, 将芳香醛和2-甲基喹啉类化合物在无溶剂或甲苯中于120 ℃反应48 h, 制备了一系列的1,3-二(2-喹啉基)丙烷化合物, 产率56%~92%, 产物结构经核磁共振波谱和高分辨质谱确证. 该方法具有简便易行、 产率较高等特点.     

低温耦合固相氮化反应合成β-Sialon

本研究拟在氮化气氛下,以金属Al粉、Si粉、α-Al2O3为原料,添加Y2O3,耦合氮化反应制备β-Sialon.通过在不同温度下的氮化反应烧结试验,研究了Y3+对β-Sialon晶相组成、晶粒大小、晶格常数及显微结构的影响.采用XRD和SEM表征试样中的晶相和显微结构,利用X'Pert Plus软件对试样进行晶胞参数分析,通过Semi-quantification法对试样各晶相组成进行计算.结果表明:随着温度的升高,合成β-Sialon相的含量不断提高,在1550℃时达到最高;添加Y2O3可以在相对较低温度条件下合成β-Sialon相,y3+对Al3+的置换作用导致β-Sialon相结构畸变,且随耦合氮化反应烧成温度的升高,晶胞体积可由1350℃时的0.208448 nm3增大到1550℃时的0.236776 nm3,合成β-Sialon相呈现增加的趋势.同时在合成β-Sialon结构中,由于过量助烧结剂Y2O3易与原料中Al2O3形成针状YAG.     

Experimental determination of interfacial energies for Ag2Al solid solution in the CuAl2--Ag2Al system

The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an Al-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus.The Gibbs-Thomson coefficient,solid-liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes.The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus,separately.     

沙疗对骨关节炎兔子股骨骨质影响的对比研究

目的:试验研究维医沙疗对骨关节炎动物模型骨质层转移的影响.方法:采用CT扫描的手段分别四次(建立实验对象OA模型前后各一次、进沙疗第14天和第28天各一次)采集两个实验对象股骨数据.将数据导入MIMICS软件分离实验对象股骨,根据CT值范围不同把股骨分为六个骨质层并读取各层体积.分析了各骨质层的体积在股骨总骨量中所占比例的变化和股骨平均CT值的变化.结果:分析四次CT数据的变化,发现沙疗对象股骨总骨量增长,而对照对象之下降.与此同时沙疗对象股骨平均CT值上升,相比之下对照对象平均CT值下降.结论:沙疗对关节炎对象有促进骨代谢作用,使骨质从低CT值的骨质层转移至高CT值骨质层.