新生儿黄疸治疗仪用LED光源的研究

为提高胆红素的光降解效应和新生儿黄疸病光疗的效果,设计研制了一种新生儿黄疸治疗仪用发光二极管(LED)光源。以实验测试的体外游离的标准胆红素溶液最有效的吸收光谱作为黄疸治疗仪光源的目标光谱,采用市面上现有的峰值波长和半峰全宽的不同单色LED作为匹配光源,将简单遗传算法作为光谱匹配算法,进行了光源光谱的匹配设计、样灯制作和光谱测试与分析。结果表明:拟合的光谱与目标光谱匹配度达到了97.62%,实际的黄疸治疗仪光源样品的光谱与目标光谱的匹配度达到了93.08%,窄带宽的单色LED能够匹配出所需要的目标光谱,光谱匹配度高,为新生儿黄疸光疗仪用光源的选择提供了研究的基础。     

一种温度/pH敏感性聚合物的合成及其溶液性能研究

通过官能团的合理设计,将具有亲水性的阳离子与具有疏水作用的苄基结合在同一单体上,合成出了具有潜在温度和pH敏感性的新型单体——二甲基苄基(2-甲基丙烯酰氧乙基)溴化铵(DMBMAAB),并用1H-NMR和液相色谱法对其结构和纯度进行了表征.DMBMAAB与丙烯酰胺(AM)在水溶液中通过自由基聚合合成出共聚物P(DMBMAAB-co-AM),用核磁和元素分析法对其结构和组成进行了表征.P(DMBMAAB-co-AM)的水溶液表现出了与聚异丙基丙烯酰胺(PNIPAAm)相反的温度响应特性,PNIPAAm具有最低临界溶解温度(LCST),而P(DMBMAAB-co-AM)具有最高临界溶解温度(HCST).当温度从50℃上升到70℃的过程中,P(DMBMAAB-co-AM)共聚物溶液的透光率和表观粘度(表观性能)发生了急剧的变化,溶液外观由乳状液变为澄清液;另一个与PNIPAAm显著不同的特性是,该聚合物还具有非常明显的pH敏感性.当pH值从11变到12时,溶液的表观性能也发生了相当剧烈的变化.此外,表面活性剂(SDS)、盐(NaCl)等外界因素也对P(DMBMAAB-co-AM)共聚物溶液的表观性能具有明显的影响.结果表明,P(DMBMAAB-co-AM)是一种具有多重响应的新型功能聚合物材料,分子链中亲水和疏水基团间的相互作用以及环境的变化是引起这一系列响应行为的主要原因.     

考虑密度与温度耦合关系的非结构网格SIMPLEC算法

提出一种新的密度压力速度和温度耦合的算法,使用静焓方程构造温度修正量与压力修正量之间的关系,类似Rhie-Chow方法用动量方程插值,网格面上的温度压力修正量插值采用能量方程的形式.CGNS API(CFD General Notation System Application Programming Interface)作为非结构化网格求解器的前处理和后处理,基于网格的FVM(Finite Volume Method)作为偏微分方程求解方法.燃烧模拟采用Arrinius-Eddy Dissipation模型.最后给出两个算例作为说明.     

Dual-Atom Support Boosts Nickel-Catalyzed Urea Electrooxidation

Nickel-based catalysts have been regarded as one of the most promising electrocatalysts for urea oxidation reaction (UOR), however, their activity is largely limited by the inevitable self-oxidation reaction of Ni species (NSOR) during the UOR. Here, we proposed an interface chemistry modulation strategy to trigger the occurrence of UOR before the NSOR via constructing a 2D/2D heterostructure that consists of ultrathin NiO anchored Ru−Co dual-atom support (Ru-Co DAS/NiO). Operando spectroscopic characterizations confirm this unique triggering mechanism on the surface of Ru-Co DAS/NiO. Consequently, the fabricated catalyst exhibits outstanding UOR activity with a low potential of 1.288 V at 10 mA cm⁻² and remarkable long-term durability for more than 330 h operation. DFT calculations and spectroscopic characterizations demonstrate that the favorable electronic structure induced by this unique heterointerface endows the catalyst energetically more favorable for the UOR than the NSOR.     

On the adjoint semigroups of p-separable BCI-algebras

We give some conditions under which the p-semisimple part SP(X) of a BCIalgebra X becomes an ideal, and prove that the adjoint semigroup of a p-separable BCI-algebra is a direct product of a negatively partially ordered semigroup and an abelian group.     

Phosphorene-Based Electrocatalysts

Phosphorene, generally defined as two-dimensional (2D) black phosphorus (BP) with monolayered or few-layered structure, has emerged as a promising member of the family of 2D materials. Since its discovery in 2014, extensive research has been focused on broadening its applications, covering the biological, photoelectric, and electrochemical fields, owing to the unique physicochemical and structural properties. As a single-elemental material, phosphorene has demonstrated its applicability for the preparation of efficient electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), nitrogen reduction reaction (NRR), and other electrocatalytic applications. In this Minireview, a summary of the very recent research progresses of phosphorene in electrocatalysis is offered, with a special focus on the effective synthetic strategies towards performance improvement. In the concluding section, challenges and perspectives are also discussed.     

Rational Control of Charge Transfer Excitons Toward High-Contrast Reversible Mechanoresponsive Luminescent Switching

A practicable strategy to rationally obtain the reversible mechanochromic luminescent (MCL) material with high-contrast ratio (green versus red) has been established. By introducing a volatile third party (small-sized solvent molecules) into the lattice of charge transfer (CT) cocrystal of mixed-stacking 1:1 coronene (Cor.) and napthalenetetracarboxylic diimide (NDI), a noteworthy reconfigurable molecular assembly is ingeniously achieved owing to the loosely packing arrangement as well as weakened intermolecular interactions. Accordingly, the CT excited state, strongly corresponding to the molecular stacking modes, can be intentionally tailored through external stimulus (heating, grinding, or solvent), accompanying distinct changes in photophysical properties. Subsequently, a high-contrast reversible MCL with highly sensitive and good reproducibility is realized and the underlying mechanism is thoroughly revealed.     

Temporal broadening of pulsed waves propagating through turbulent media

Pulse signals, propagating through a turbulent medium such as the ionosphere, can be distorted by dispersion and scattering from both the background medium and irregularities embedded in. Thus, the mean square pulse width is changed, and temporal broadening is introduced. We carry out a study on the temporal broadening with theoretical analyses and numerical simulations by using an analytical solution of two-frequency mutual coherence function obtained recently by iteration. As a case of study, pulse broadening is investigated in detail in trans-ionospheric propagation. Results show that most contributions are mainly from the dispersion of the background ionosphere and scattering effects of electron density irregularities in most cases.     

自由软件R及其在化学中的应用

论述了在科学研究领域中推广自由软件的重要性,并就其中的典型代表———统计处理软件R在化学领域中的应用列举了三个实例:分子动力学数据的统计分析、物理化学实验数据处理及碳纳米管分子模型的构建,给出了详细操作步骤。除文中列举的实例外,R还可被应用于化学模式识别、图形制作等领域,是化学工作者处理实际问题的一大利器。