Towards the object-oriented design of active hydrogen evolution catalysts on single-atom alloys

Given a desired property, locating relevant materials is always highly desired but very challenging in a range of areas, including heterogeneous catalysis. Obviously, object-oriented design/screening is an ideal solution to this problem. Herein, we develop an inverse catalyst design workflow in Python (CATIDPy) that utilizes a genetic-algorithm-based global optimization method to guide on-the-fly density functional theory calculations, successfully realizing the highly accelerated location of active single-atom alloy (SAA) catalysts for the hydrogen evolution reaction (HER). 70 binary and 752 ternary SAA candidate catalysts are identified for the HER. Furthermore, via considering the segregation stability and cost of materials, we extracted 6 binary and 142 ternary SAA candidate catalysts that are recommended for experimental synthesis. Remarkably, guided by these theoretical identifications, homogeneously dispersed Ni-based bimetallic catalysts (e.g., NiMo, NiAl, Ni₃Al, NiGa, and NiIn) were synthesized experimentally to test the reliability of the CATIDPy workflow, and they showed superior HER performance to bare Ni foam, indicating huge potential for use in real-world water electrolysis techniques. Perhaps more importantly, these results demonstrate the capacity of such a proposed approach for investigating unexplored chemical spaces to efficiently design promising catalysts without knowledge from the expert domain, which has far-reaching implications.

An inverse catalyst design workflow in Python (CATIDPy) for discovering unexplored chemical spaces successfully realized the highly accelerated location of active single-atom alloy (SAA) catalysts for the hydrogen evolution reaction (HER).     

层状双金属氢氧化物及其复合材料加速电解水制氢的研究进展

随着经济社会的不断发展和能源的不断消耗,开发清洁能源已引起研究者们的广泛关注。层状双金属氢氧化物(LDH)具有典型的层状结构、制备难度低、组成易调节等优点,在电催化分解水方面表现出可与贵金属催化剂相媲美的性能。目前LDH催化剂仍然存在稳定性不足、活性位点辨别不明、电催化反应机理模糊不清等科学问题亟待解决。本文首先介绍了LDH材料的性质和制备方法,重点从元素和化合物对LDH材料结构和性能的调控、取代阳极OER以及海水氧化三个方面综述了LDH材料在电催化制氢方面的研究进展,阐述了LDH复合材料的形貌、界面作用及化合物之间的协同作用。最后对LDH材料更深层次的研究方向作出展望。     

Development of Vancomycin-Capped β-CD-Bonded Silica Particles as Chiral Stationary Phase for LC

Vancomycin-capped (3-(2-O-β-cyclodextrin)-2-hydroxypropoxy)-propylsilyl-appended silica particles (VCD-HPS), a new type of substituted β-cyclodextrin-bonded chiral stationary phase (CSP) for liquid chromatography (LC), have been synthesized by treatment of bromoacetate-substituted-(3-(2-O-β-cyclodextrin)-2-hydroxypropoxy)-propylsilyl-appended silica particles (BACD-HPS) with vancomycin in anhydrous methanol. The stationary phase is characterized by elemental analysis. This new CSP has a chiral selector with two recognition sites: vancomycin and β-cyclodextrin (β-CD), which can provide multiple interactions with the solutes. The chromatographic performance of VCD-HPS was studied with several disubstituted benzenes and some chiral drug compounds as solutes in reversed-phase LC. The results show that VCD-HPS has excellent selectivity for the separation of aromatic positional isomers and enantiomers of chiral compounds.     

Repeated probing of Southwestern blots using alkaline phosphatase stripping

Southwestern blotting is when a DNA sequence is used to probe DNA-binding proteins on an electrophoretic gel blot. It would be highly desirable to be able to probe a blot repeatedly with different DNA sequences. Alkaline phosphatase can remove 5'-phosphoryl groups from DNA and radiolabeled 5'-(32)P-DNA probes are commonly used in Southwestern blotting. Here is shown that once probed, the radioisotope signal on the blot can be effectively removed by brief digestion with alkaline phosphatase, and the blot can then be repeatedly probed at least six times with different DNA probes. This exceeds the repetitions possible with another commonly used method using SDS. The technique can be used with either one-dimensional or multi-dimensional Southwestern blots and does not have a large effect on the phosphorylation state of the blotted proteins. An alternative method using T4 polynucleotide kinase stripping is also introduced but was less well characterized.     

Preparation of chitosan functionalized monolithic silica column for hydrophilic interaction liquid chromatography

A novel cationic hydrophilic interaction monolithic stationary phase based on the chemical modification of carboxymethyl chitosan (CMCH) to the monolithic silica skeleton using carbodiimide as an activation reagent was prepared for performing capillary liquid chromatography. The amino and hydroxy moieties of CMCH functioned as both the ion-exchange sites and polar providers. The performance of the column was studied by the separation of polar acidic compounds. The chitosan functionalized monolithic silica column showed good selectivity for nucleosides, nucleotides, aromatic acids and aliphatic acids. The mechanism for the separation of these compounds was also studied. The results showed that these compounds were separated primarily based on the hydrophilic interaction mechanism.     

高效液相色谱-串联质谱测定猪肉中3种β-受体激动剂残留量

建立一种同时测定猪肉中3种β-受体激动剂残留量的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)确证分析方法。样品经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解、乙酸铵缓冲液提取和MCX固相萃取柱净化,采用Agilent ZorbaxSB-C18(2.1mm×150mm,3.5μm)色谱柱,0.1%的甲酸水溶液、甲醇和乙腈作为流动相进行洗脱,高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行检测,内标法定量。3种药物在0.05～1μg/kg浓度范围内线性良好,相关系数r均大于0.999,0.05、0.1、0.5μg/kg3个浓度水平的添加回收率在89.7%～106.7%之间,相对标准偏差为2.4%～8.6%,3种药物的定量限均为0.05μg/kg。方法适用于猪肉中β-受体激动剂残留的确证分析。     

HPLC-MS-MS法测定水体中残留的氨基甲酸酯类农药

应用高效液相色谱-串联质谱(HPLC-MS-MS)联用技术,建立了检测水体中氨基甲酸酯类农药残留的方法。水样经氨基柱固相萃取,二氯甲烷洗脱,梯度流动相洗脱,电喷雾正离子(ESI+)模式采集、选择反应性监测模式(SRM)对定性、定量离子进行MS/MS测定。5种氨基甲酸酯类农药在5～200ng/L范围内线性关系良好,回收率为80%～92%,相对标准偏差均小于10%,方法检出限分别为:异丙威和仲丁威为1.4ng/L,克百威和甲萘威为1.5ng/L,恶虫威为1.6ng/L。该方法适用于水体中氨基甲酸酯类农药残留的检测。     

差分脉冲伏安法同时测定α-山竹黄酮和γ-山竹黄酮

研究了α-山竹黄酮和γ-山竹黄酮在玻璃碳电极上的电化学行为,研究了pH和静置时间等因素的影响,探讨了α-山竹黄酮和γ-山竹黄酮在玻璃碳电极上的氧化机理,建立了差分脉冲伏安法同时测定α-山竹黄酮和γ-山竹黄酮的方法。在pH 3.1的BR缓冲介质中,α-山竹黄酮在0.822 V产生灵敏的氧化峰,γ-山竹黄酮在0.426 V和0.700 V产生灵敏的氧化峰。对α-山竹黄酮,相应的氧化峰的峰高与浓度在5.00×10-6mol/L~2.00×10-4mol/L范围内呈良好的线性关系,线性相关系数为0.9950;对γ-山竹黄酮,其在0.426 V氧化峰的峰高与浓度在2.00×10-5mol/L~6.00×10-4mol/L浓度范围内呈良好的线性关系,线性相关系数为0.9904。该方法测量2.00×10-4mol/L的α-山竹黄酮和γ-山竹黄酮相对标准偏差分别为3.3%和4.1%(n=10)。     

水热法合成BiVO4可见光催化剂

采用水热法,无需添加剂,在180℃通过调控pH值制备了不同结构和形貌的BiVO4可见光催化剂。利用XRD、SEM等手段对样品进行表征。结果表明,水热反应液pH值对BiVO4的晶相与形貌均有很大影响,pH为4时制备的片状BiVO4对亚甲基蓝的降解率最高（4h达91.79%）。     

基于FPGA的视频信号数字化光纤传输实验接收装置的设计与实现

介绍了以FPGA为主控芯片,以光纤为通讯媒介的视频信号数字通信实验装置的设计实现过程,并对电路各个模块的功能及实现加以说明.电路在Altium Designer中设计完成,采用分模块式的设计,结构清晰,易于实现.在QuartusⅡ环境下用VerilogHDL语言进行编程并对程序进行仿真.该装置已做成了实体,可以实现视频信号的传输.