CHLOROMETHYLATION OF POLYMERS MADE FROM TECHNICAL DIVINYLBENZENE AND PROPERTY OF THE CHLOROMETHYLATED POLYMERS

The goal this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents.Forthis study,the factors,that effect the chloromethylation reaction,such as the pore structure of the polymer,the ratio of the reactants to catalyst,the reaction temperature and reaction time and so on were investigated.and the pore structure and property of the chloromethylated polymers were studied.The results showed that polymers of technical divinylbenzene could be chloromethylated successfully,and the adsorptive property of the chloromethylated resin was different from that of the initial resin.     

苯在Ag(100)表面吸附的周期性密度泛函理论研究

 采用量子化学中的密度泛函理论结合平板周期模型方法,研究了苯在Ag(100)面上的吸附方式和相对稳定性. 通过对不同吸附位置的吸附能和几何构型参数的比较发现,苯在Ag(100)表面的吸附属于较强的化学作用,穴位吸附的稳定性优于桥位,顶位吸附最不稳定. 吸附的苯分子的平衡构型发生扭曲, C-C键有较大程度的伸长; C-H键的键长基本不变,但是偏离苯环平面,并背离Ag(100)表面. 在吸附过程中,电子由苯向表面银原子转移. 本文给出了详细的轨道示意图和电荷布居分析,并且与相关的实验和理论研究结果进行了比较.     

碳包覆Pd/TiO2光催化产氢协同胺类选择性氧化合成亚胺(英文)

负载型金属纳米催化剂由于其优异的光催化性能,被广泛应用于光催化产氢协同胺类氧化偶联合成高附加值亚胺体系。但在反应过程中,金属表面对H原子和亚胺表现出较强的吸附能力,导致了亚胺易于发生自氢化反应而生成仲胺,显著降低了亚胺的选择性。在本文中,我们证实了在Pd/Ti O₂表面构建超薄碳层(Pd/Ti O₂@C)是一种解决上述问题的有效策略。在Pd/Ti O₂表面构筑的超薄碳层可以有效调控H原子和亚胺在其表面的吸附行为,避免了光催化氧化偶联过程中亚胺的自氢化。因此,Pd/Ti O₂@C光催化剂在光催化产氢协同胺类选择性氧化合成亚胺体系中展现出优异的亚胺选择性。本研究提供了一种便捷有效的策略推动负载型金属纳米催化剂在光催化产氢协同合成高附加值产物体系中的应用。     

H2S2的构型及其异构化反应的密度泛函理论研究

采用量子化学中的密度泛函理论B3LYP方法 ,在 6 3 11+G(3df,2p)水平上 ,全优化得到了H2 S2 线型和分叉型两种异构体的平衡结构 ,讨论了分叉型异构体存在的可能性 ,同时对可能发生的分子内原子迁移过程的过渡态进行了考察 ,并采用内禀反应坐标 (IRC)加以证实 .计算结果表明 ,从能量角度看 ,线型的HSSH为稳定构型 .热力学和动力学的计算则表明 ,分子内的原子转移需要较高的活化能 ,并且速度很慢 ,分叉型异构体存在的可能性较小     

Comprehensive Investigation on Ginsenosides in Different Parts of a Garden-Cultivated Ginseng Root and Rhizome

Background: Ginseng is widely used as herb or food. Different parts of ginseng have diverse usages. However, the comprehensive analysis on the ginsenosides in different parts of ginseng root is scarce. Methods: An ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) combined with UNIFI informatics platform and ultra-high-performance liquid chromatography-charged aerosol detection (UHPLC-CAD) were employed to evaluate the different parts of cultivated ginseng root. Results: 105 ginsenosides including 16 new compounds were identified or tentatively characterized. 22 potential chemical markers were identified, 20, 17, and 19 for main root (MR) and fibrous root (FR), main root (MR) and branch root (BR), and main root (MR) and rhizome (RH), respectively. The relative contents of Re, Rb₁, 20(R)-Rh₁, Rd, and Rf were highest in FR. The relative content of Rg₁ was highest in RH. The total relative content of pharmacopoeia indicators Rg₁, Re, and Rb₁ was highest in FR. Conclusion: The differences among these parts were the compositions and relative contents of ginsenosides. Under our research conditions, the peak area ratio of Rg₁ and Re could distinguish the MR and FR samples. Fibrous roots showed rich ingredients and high ginsenosides contents which should be further utilized.     

CaNiN能带结构及其磁性与构型畸变关系的密度泛函 研究

采用密度泛函方法研究了CaNiN的电子结构及其金属性和磁性,结果表明,由于弱的空间偶合作用,该化合物中一唯(1D)NiN^2-链的能带结构(Γ→X)集中反映了CaNiN的二维(2D)以及三维(3D)能带的主要特征,其能带结构揭示了CaNiN的金属性和磁性的本质,将1DNiN^2-链的结果与[MX](M=Pt,Pd,Ni;X=Cl,Br,I)对比,阐述了畸变发生的本质在于空间轨道能量的降低与核间排斥能及电子相互作用能的升高竞争的结果,发现后者占优势则不发生畸变,畸变越小越有利于材料具有顺磁性。     

吸附树脂AB—8对甜菊甙的吸附性能及在其提取纯化中的应用

考察了大孔吸附树脂ＡＢ－８对甜菊甙的吸附性能，和溶液的ＨＰ值，洗脱剂的种类及流速对树脂吸附，脱附性能的影响，结果表明，ＡＢ－８树脂对甜菊甙吸附量高，循环使用性能好且易于洗脱。     

Mo-S簇合物与“松散”配位键的研究

通过对Mo3S_4[S_2P(OEt)_2]_4·H_2O的电子结构计算和分子轨道分析,讨论了Mo—S簇合物中“松散”的端基配位键的轨道组成,它们与簇胳成键性质的联系和形成机理。     

吸附树脂AB－8对甜菊甙的吸附性能及在其提取纯化中的应用

考察了大孔吸附树脂ＡＢ－８对甜菊甙的吸附性能，和溶液的ｐＨ值、洗脱剂的种类及流速对树脂吸附，脱附性能的影响；结果表明，ＡＢ－８树脂对甜菊甙吸附量高，循环使用性能好且易于洗脱。     

Chemical anisotropies of carbon nanotubes and fullerenes caused by the curvature directivity

The directional-curvature theory is developed as a rational basis for the strain energy and the chemical reactivity in single-walled carbon nanotubes (SWCNTs) and fullerenes. The directional curvature KD and its mean KM, derived from this theory, cover the overall curvatures of their bonds and atoms and break through the limitations of the pyramidalized-angle thetap approach, which is only available to atomic curvature. The directional-curvature theory demonstrates that KD and KM depend directly on the strain or reactive binding energies of the bonds and atoms and that there is approximate curvature conservation in SWCNTs and fullerenes. Application of this theory to addition reactions of various SWCNTs and fullerenes shows that the slope of the straight line between the strain or binding energies and KD is close to a constant, which helps clarify the puzzle as to why some functionalizations of C70 occur at the relatively flat midsection.