模拟体内微环境筛选与肿瘤细胞作用的中药活性成分

利用三维(3D)细胞反应器模拟体内微环境,建立了一种与肿瘤细胞作用的活性分子的筛选和分析方法.利用药物与三维细胞反应器中活肿瘤细胞和固化肿瘤细胞分别作用后的HPLC生物指纹谱峰面积之间有无显著性差异,建立了与细胞结合的活性成分的筛选识别模型.已知抗肿瘤药物紫杉醇和白藜声醇的谱峰均具有显著性差异,而非抗肿瘤药物酮洛芬和青霉素G的谱峰均没有显著性差异,证明利用该模型筛选识别与细胞结合的活性成分是可行的.此外,应用该模型从中草药桃儿七提取物中筛选出了7种可作用于Lovo细胞的活性成分.此研究提供了一种模拟体内微环境下与肿瘤细胞作用的活性成分的筛选和分析方法,在药物发现环节,特别是中草药活性成分研究中具有潜在的应用价值.     

Predicted a honeycomb metallic BiC and a direct semiconducting Bi2C monolayer as excellent CO2 adsorbents

We predicted two stable two-dimensional materials of carbon and bismuth elements, namely BiC and Bi₂C monolayers. The stabilities of two monolayers were examined by cohesive energy, Born criteria, firstprinciple MD simulations and phonon spectra, respectively. By including the spin-orbit coupling effects,the Bi C monolayer is a metal and the Bi₂C monolayer possesses a narrow direct（indirect） band gap of 0.403（0.126） e V under the HSE06（GGA-PBE） functional. For the adsorptio...     

Tailoring the surface structure of iron compounds to optimize the selectivity of 3-nitrostyrene hydrogenation reaction over Pt catalyst

Selective hydrogenation of substituted nitroarenes is an important reaction to obtain amines.Supported metal catalysts are wildly used in this reaction because the surface structure of supports can tune the properties of the supported metal nanoparticles （NPs） and promote the selectivity to amines.Herein,Pt NPs were immobilized on Fe OOH,Fe₃O₄andα-Fe₂O₃nanorods to synthesize a series of iron compounds supported Pt catalysts by liquid phase reduction me...     

基于雨课堂和BOPPPS改进模型的教学设计——以大学化学课程为例

在高等学校专业课程教学中融入思政教育教学的理念,是以"立德树人"为教育根本任务的基本要求。结合结构化学课程特点和教学内容,以"培养学生的哲学观和科学观、培养学生民族自豪感和自信心"的目标为切入点,提出结构化学教学中思政元素的融入策略,发挥结构化学课程的"育德功能",实现知识传授和价值引领的有机统一。     

Boosting electrocatalytic selectivity in carbon dioxide reduction: The fundamental role of dispersing gold nanoparticles on silicon nanowires

Carbon dioxide electrochemical reduction (CO₂RR) has been recognized as an efficient way to mitigate CO₂ emissions and alleviate the pressure on global warming and associated environmental consequences. Gold (Au) is reported as stable and active electrocatalysts to convert CO₂ to CO at low overpotential due to its moderate adsorption strength of *COOH and *CO. The request for improved catalytic performance, however, is motivated by current unsatisfied catalytic selectivity because of the side hydrogen evolution reaction. In this context, the design of Au based binary catalysts that can boost CO selectivity is of great interest. In the present work, we report that Au nanoparticles can be feasibly dispersed and anchored on silicon nanowires to form Au-Si binary nanomaterials. The Au-Si may stably drive CO₂RR with a CO Faraday efficiency of 95.6% at ?0.6 V vs. RHE in 0.5 mol/L KHCO₃ solution. Such selectivity outperforms Au particles by up to 61%. Controlled experiments illustrate that such catalytic enhancement can chiefly be ascribed to electronic effects of binary catalysts. Theoretical calculations reveal that spontaneously produced silicon oxide may not only inhibit hydrogen evolution reaction, but also stabilize the key intermediate *COOH in CO formation.     

一步硫/磷热处理制备空心Co9S8/CoP/C纳米复合材料及其储钠性能研究

低成本、高性能的钠离子电池有望成为代替锂离子电池的下一代核心器件.但是开发出高比容量、高倍率的钠离子电池负极材料依然是瓶颈.本文通过水热/溶剂热法制备了Co基前驱体,然后将其一步硫/磷热处理制得具有空心多孔结构的h-Co₉S₈/CoP/C纳米复合材料.通过X-射线粉末衍射(XRD)、拉曼光谱(Raman)、扫描电镜(SEM)、透射电镜(TEM)和X-射线光电子能谱(XPS)等表征以确定纳米复合物的物相以及形貌特征.当h-Co₉S₈/CoP/C作为钠离子电池负极材料时,该电极材料展示了高的比容量(561 mAh g^-1@0.1 Ag^-1)、较好的循环性能(可逆比容量200 mAh g^-1@2 Ag^-1)和倍率性能.h-Co₉S₈/CoP/C之所以显示出良好的储钠性能,主要得益于其空心多孔结构不仅提供更多的空间缓解钠在反复嵌入和脱出过程造成的体积膨胀效应,而且可以缩短离子/电荷扩散途径以加快反应动力学,此外,Co₉S₈、CoP和C独特的电子结构优势得以共同发挥.     

Prediction of stable BC3N2 monolayer from first-principles calculations: Stoichiometry,crystal structure,electronic and adsorption properties

In this paper, a novel BC₃N₂ monolayer has been found with a graphene-like structure using the developed particle swarm optimization algorithm in combination with ab initio calculations. The predicted structure meets the thermodynamical, dynamical, and mechanical stability requirements. Interestingly, the BC₃N₂ plane shows a metallic character. Importantly, BC₃N₂ has an in-plane stiffness comparable to that of graphene. We have also investigated the adsorption characteristics of CO₂ on pristine monolayer and Mo functionalized monolayer using density functional theory. Subsequently, electronic structures of the interacting systems (CO₂ molecule and substrates) have been preliminarily explored. The results show that Mo/BC₃N₂ has a stronger adsorption capacity towards CO₂ comparing with the pristine one, which can provide a reference for the further study of the CO₂ reduction mechanism on the transition metal-functionalized surface as well as the new catalyst’s design.     

过渡态理论在化学体系中的2个应用实例*

在大学本科一二年级的物理化学教学中,化学动力学章节的学习涉及到对不同时间尺度的认识。本文利用过渡态理论得到的速率常数表达公式,以乙烷分子碳/碳单键旋转和水分子氢键交换的动力学过程为例,对这2个应用实例的动力学过程所发生的时间尺度做出估算。这些时间尺度的估算对于学生理解不同动力学过程的物理图像至关重要,同时也有助于加强学生对重要公式的理解并能够将这些公式在化学体系中灵活运用。     

Multiple mobility edges in a 1D Aubry chain with Hubbard interaction in presence of electric field: Controlled electron transport

Electronic behavior of a 1D Aubry chain with Hubbard interaction is critically analyzed in presence of electric field. Multiple energy bands are generated as a result of Hubbard correlation and Aubry potential, and, within these bands localized states are developed under the application of electric field. Within a tight-binding framework we compute electronic transmission probability and average density of states using Green's function approach where the interaction parameter is treated under Hartree–Fock mean field scheme. From our analysis we find that selective transmission can be obtained by tuning injecting electron energy, and thus, the present model can be utilized as a controlled switching device.