基于虚拟现实的分子对接教学软件*

由于其强大的沉浸性和交互性等特征,虚拟现实技术在教育教学方面有着独特的优势。基于分子建模工具和虚拟现实技术构建了一种关于分子对接的教学软件,该软件将语音讲解、动画演示、分子可视化、交互操作等内容有机整合在虚拟现实环境中,从理论知识讲解和VR实验操作2个方面展开,深入浅出地讲解了分子对接的知识点,达到辅助教学的目的。     

用于爆炸物探测的X射线相干散射技术研究

建立了基于X光机的相干散射实验装置, 对用于爆炸物探测的X射线相干散射技术进行了研究. 在一个固定的角度下(6.5°), 测量了多种常见爆炸物和非爆炸物的相干散射谱. 结果表明, 每种爆炸物都有特定的相干散射谱线, 包含了与物质化学组分相关的"指纹信息". 使用这一方法可以将爆炸物从常见的非爆炸物中鉴别出来.     

一维纳米材料Cs0.2WO3和W18O49长度与红外吸收关联性的Mie散射理论推导及实验验证

研究表明二元、三元钨基氧化物的红外吸收性能具有尺寸和形貌依赖性,但还没有普适性的物理学机理及计算方法。本工作基于Mie散射理论,推导了一维材料的长度与光吸收性能之间的关系,通过理论推导计算和实验验证,探究了纳米钨基氧化物的红外吸收性能与颗粒长度的关联性。首先,基于Mie散射理论的推演和计算,揭示了增加纳米Cs_(0.2)WO_3和W_(18)O_(49)材料长度可适度提高其近红外吸收性能的规律。其次,测试了合成的不同长度Cs_(0.2)WO_3纳米棒和W_(18)O_(49)纳米线的红外吸收性能,结果与理论计算及模拟相吻合。其中在2 500～20 000 nm波长范围内Cs_(0.2)WO_3纳米棒和W_(18)O_(49)纳米线随长度的变化趋势不同,Cs_(0.2)WO_3纳米棒的红外吸收性能随长度的增加而增加,而W_(18)O_(49)纳米线的红外吸收性能随长度的增加而减弱。Cs_(0.2)WO_3纳米棒和W_(18)0O_9纳米线的光热效应均随长度的增加而增加,增幅分别达18.5%和12.7%,再次验证了长度效应。     

碳量子点/纳米金@碳纳米管修饰电极同时检测鸟嘌呤和腺嘌呤

制备了一种碳量子点(CQDs)/金纳米颗粒(AuNPs)@羟基化多壁碳纳米管(MWCNT-OHs)复合膜修饰电极用于鸟嘌呤(GA)和腺嘌呤(AE)的同时检测.与裸电极和其它修饰电极相比,复合膜修饰电极能显著提高GA和AE的氧化峰电流及峰电位差,能够对GA和AE同时高灵敏检测.研究了GA和AE在复合膜修饰电极上的电化学行为,结果表明,在0.2 mol/L PBS(pH 7.0)中,GA和AE的氧化峰电流与浓度分别在1～200 μmol/L和2～80μmol/L范围内呈良好的线性关系,检测限分别为0.9和1.8 μmol/L.将该修饰电极用于人体血清样品中GA和AE的同时电化学检测,加标回收率在90.4％～107.4％之间,证明了该修饰电极在生物样品分析领域的应用潜力.     

A New Porous Cadmium(Ⅱ) Complex Based on 1,10-Phenanthroline Derivative and Dicarboxylate:Syntheses,Structure, Thermal Behavior and Luminescence

A new porous Cd(Ⅱ) coordination compound, namely, [Cd(bpdc)(L)2]·3H2O(1, L = 11-fluoro-dipyrido[3,2-a:2,3-c]phenazine and bpdc = 1,1-biphenyl-2,2-dicarboxylate) was synthesized under hydrothermal conditions, and characterized by single-crystal X-ray diffraction. It crystallizes in tetragonal, space group P4122 with a = 9.8486(4), b = 9.8486(4), c = 45.925(4)A, V = 4454.5(5) 3, Z = 4, C50H29 Cd F2N8O7, Mr = 1004.21, Dc = 1.497 g/cm3, F(000) = 2028, μ(Mo Ka) = 0.562 mm-1, R = 0.0566 and w R = 0.1585. Each Cd(Ⅱ) atom is coordinated by one bpdc anion and two L ligands to give a discrete molecule. Neighboring discrete molecules are stacked by π-π interactions among L ligands, resulting in an interesting 1D supramolecular chain. Moreover, the 1D supramolecular chains are packed with each other to give a porous structure, in which an infinite channel is filled with water molecules. In addition, the thermal behavior and luminescent property of 1 have also been studied.     

聚L-谷氨酸苄酯固定相的制备及色谱评价

利用L-谷氨酸苄酯开环聚合得到聚L-谷氨酸苄酯,对其进行表征,将聚L-谷氨酸苄酯溶于四氢呋喃后涂敷在3-氨丙基三乙氧基硅胶上制得液相色谱固定相,研究了正相色谱条件下聚L-谷氨酸苄酯涂敷型固定相对9种位置异构体及10种手性化合物的拆分能力。以不同比例的正己烷/异丙醇为流动相,有6种位置异构体(o,m,p-氯苯胺、o,m,p-溴苯胺、o,m,p-碘苯胺、o,m,p-硝基苯胺、o,m,p-二硝基苯和o,m,p-苯二胺)和4种手性化合物(1-(对氯苯基)乙醇、5-二硝基-N-(1-苯乙基)苯甲酰胺、华法林和四咪唑)得到不同程度的拆分,表明聚L-谷氨酸苄酯涂敷型固定相对位置异构体具有较好的识别作用,同时也表现出良好的手性拆分能力。     

XANES技术探究酸处理对义马煤中硫形态及其热变迁行为的影响

利用XANES技术研究了酸处理对义马煤的比表面积、体相及表面硫形态分布和热解过程中硫变迁行为的影响。结果表明,由于酸处理过程中部分镶嵌于有机质中的矿物质被脱除导致部分闭合孔打开,煤的比表面积有所增大。HCl-HF和HCl-HF-HNO_3处理脱除了煤中大部分矿物质和无机硫,由于HNO_3的强氧化性,YMN中亚砜和砜硫化物的相对含量均高于YMR和YMD。相比煤样体相,酸处理过程对表面形态硫的分布产生了更为明显的影响。酸处理煤样热解含硫气体释放量减少,但由于大部分碱性矿物质的脱除和煤中易分解形态硫相对含量的增加,含硫气体释放率增加。不同形态硫之间的内部转化使得酸处理煤焦中主要形态硫的分布更为均匀。通过HCl-HF-HNO_3处理可以有效地脱除煤中矿物质及无机硫,并改变煤中形态硫分布,从而为高灰分、富含黄铁矿的高硫煤的利用提供指导。     

气相色谱正构烷烃和直链脂肪酸甲酯两种线性保留指数之间的转换方法

保留指数是气相色谱中用于化合物结构鉴定的重要工具。本研究对基于正构烷烃和直链脂肪酸甲酯的线性保留指数进行线性拟合,发现在所设定的4种不同的升温条件下两种保留指数之间呈现较为固定的线性关系：在弱极性柱（固定液为5%苯基和95%的甲基聚硅氧烷）和极性柱（固定液为聚乙二醇）条件下,正构烷烃保留指数（y）与脂肪酸甲酯保留指数（x）之间的关系分别为y=1.0051x+318.51（r²=1）和y=1.0362x+562.519（r²=1）。采用文献保留指数对所建立的线性关系进行验证,发现通过公式换算得到的保留指数均在其对应文献值的均值加减方差范围内,说明换算公式真实有效。两种保留指数之间关系的建立对于化合物结构鉴定时扩大保留指数搜索范围、减少保留指数测定实验具有重要意义。     

In situ Carbon Modification of g-C3N4 from Urea co-Crystal with Enhanced Photocatalytic Activity Towards Degradation of Organic Dyes Under Visible Light

An in situ strategy was introduced for synthesizing carbon modified graphitic carbon nitride(g-C₃N₄) by using urea/4-aminobenzoic acid(PABA) co-crystal(PABA@Urea) as precursor materials. Via co-calcination of the PABA co-former and the urea in PABA@Urea co-crystals, C guest species were generated and compounded into g-C₃N₄ matrix in situ by replacing the lattice N of the carbon nitride and forming carbon dots onto its layer surface. The carbon modification dramatically enhanced visible-light harvesting and charge carrier separation. Therefore, visible light photo-catalytic oxidation of methylene blue(MB) pollution in water over the carbon modified g-C₃N₄(C/g-C₃N₄) was notably improved. Up to 99% of methylene blue(MB) was eliminated within 60 min by the optimal sample prepared from the PABA@Urea co-crystal with a PABA content of 0.1%(mass ratio), faster than the degradation rate over bare g-C₃N₄. The present study demonstrates a new way to boost up the photocatalysis performance of g-C₃N₄, which holds great potential concerning the degradation of organic dyes from water.     

Meta-DNA Strategy to Assemble DNA Structures in Submicrometre and Micrometre Scale

To break through the size limitation in DNA structure assembly and to achieve the construction of DNA structures with submicrometre and micrometre scale, Fan and Yan et al. proposed a versatile DNA structure assembly strategy, named as meta-DNA(M-DNA) strategy. Submicrometre-sized M-DNA, which has a six-helix bundle DNA origami nanostructure, is used as building block to precisely assemble a series of submicrometre-to-micrometre-sized DNA architectures with customed shapes, including meta-multi-arm junctions, polyhedrons and closely packed lattices. Besides static assembly, the proposed M-DNA strategy was also demonstrated to work well for the programmed dynamic rearrangement of DNA structures. This work has been published online in the Nature Chemistry on September 7, 2020.