Research Progress of Carbon-Encapsulated Iron-Based Nanoparticles Electrocatalysts for Zinc-Air Batteries北大核心CSCD

Zinc-air batteries (ZABs) are regarded as one of the most promising candidates for a new generation of advanced energy conversion and storage devices,while the inferior activity and stability of air cathode electrocatalysts largely hinder the widespread application of ZABs. The extensive efforts for exploring and designing high active yet stable air cathode catalysts is,therefore,indispensable for the improvement of ZABs performance. Recently,carbon-encapsulated iron-based nanoparticles have been reported to exhibit excellent oxygen catalytic performance on account of their resistance to corrosion,oxidation,and aggregation under harsh conditions,and have been widely used as cathode materials for ZABs. As a result,we systematically summarize the applications of carbon-encapsulated transition metal iron-based materials as cathode catalysts for ZABs. In this review,the basic principle of ZABs and challenges faced by air cathode catalysts are firstly expounded. Then, the research progress of the carbon-encapsulated iron-based nanoparticles electrocatalysts (such as iron-based and its alloy,carbide,oxide and phosphide,et al.) are emphatically discussed and analyzed. Finally,the future development perspectives of carbon-encapsulated iron-based electrocatalysts in the applications of ZABs are put forward. © 2022, Science Press (China). All rights reserved.     

Research Progress of Regulation of Driving Forces in Short Peptide Supramolecular Self-Assembly北大核心CSCD

Some short peptides can spontaneously self-assemble into various nanostructures via the synergistic driving forces of non-covalent interactions. These non-covalent interactions,including electrostatic interaction,hydrogen bonding,aromatic interactions and other non-covalent interactions,are usually highly coupled together. Through rational sequence design and proper modification of short peptide molecules,the driving forces could be regulated purposively,and the nanostructures and morphologies of the self-assemblies could be controlled accordingly,and thus so as to achieve the fabrication of peptide-based supramolecular biomaterials and develop their functions. In this paper,the effects of hydrogen bonding,π-π stacking, electrostatic interaction,hydrophobic interaction,metal ion coordination and chiral center on the self-assembly behavior of peptide self-assembly have been reviewed. The driving force regulation strategies, including sequence design,pH and concentration adjustment and metal ion coordination,and the resulted nanostructures have also been discussed. We also make the outlooks on the development of peptide-based supramolecular biomaterials with specific functions in biomedicines and biocatalysis. © 2022, Science Press (China). All rights reserved.     

Advances in chromatographic analysis of ginsenosidesEI北大核心CSCD

Ginsenosides possess pharmacological activities such as anti-aging,cardiovascular protection,and improving immunity. However,the detection and analysis of ginsenosides commonly suffer from the problem of low sensitivity owing to the complex matrix and low content of ginsenosides. Chromatographic technology was often used to detect ginsenosides owing to the advantages of high accuracy,high sensitivity,good reproducibility and low sample consumption,etc. In this review,the application of chromatographic analysis technologies in ginsenosides detection was summarized. First of all,accuracy of test results for the ginsenosides can be effectively improved by using high performance liquid chromatography（HPLC）combined with various detectors. Secondly,the combination of HPLC with mass spectrometry can be utilized for qualitative and quantitative analysis of ginsenosides, as well as other fields, such as metabonomics, pharmacokinetics, intestinal microorganisms and quality control. Moreover,the application of gas chromatography in analysis of ginsenosides was reviewed. Briefly,with the continuous development of chromatographic technology,the degree of accuracy for ginsenosides detection was effectively improved,which is beneficial to realize the effective analysis of ginsenosides. © 2023, Youke Publishing Co., Ltd. All rights reserved.     

Research Progress in Hydrogen Evolution Low Noble/Non-Precious Metal Catalysts of Water Electrolysis北大核心CSCD

Hydrogen energy technology with hydrogen as an energy carrier is gaining more and more attention due to its cleanliness and high energy density.Hydrogen fuel cell vehicles have been listed as one of the ultimate energy technologies in the 21st century.Among them, sustainable hydrogen production technology is a necessary prerequisite for the future development of hydrogen energy economy.Electrolyzed water technology driven by renewable resources represents an important way to support the sustainable development of hydrogen energy economy.The development and utilization of high activity, low cost hydrogen evolution catalysts is a key factor in improving the efficiency and reducing the cost of water electrolysis technology.This paper mainly introduces the recent research progress of hydrogen evolution catalysts including low platinum catalysts and non-platinum transition metal catalysts such as metal sulfides metal phosphides, metal selenides, etc; catalytic properties, synthesis methods, and structure-catalytic properties.Finally, the advantages and challenges of water electrolysis low platinum and non-platinum transition metal catalysts in the future development are prospected. © 2018 Chinese Chemical Society. All rights reserved.     

Research progress of rapid detection of typical environmental pollutants based on chromatographic technologiesEI北大核心CSCD

对复杂环境介质中的典型污染物进行快速、精准甚至远程连续自动的检测,是控制环境污染、确保环境和生态安全的重要前提。近年来,基于色谱技术的典型环境污染物快速检测方法发展迅猛,主要包括样品快速制备和目标物快速检测两方面。辅助萃取、快速液相萃取、QuEChERS等样品前处理方法具有萃取效率高、溶剂消耗少、操作简便快速等优点。快速检测技术可在几秒到半小时内提供检测结果,主要包括实验室和现场检测。本文综述了2019年以来基于色谱技术的典型环境污染物快速检测研究新进展。介绍了萃取技术和基于试验设计的样品快速制备,实验室快速检测、便携仪器现场检测及遥感技术远程检测,提出了色谱技术快速检测环境污染物的挑战和展望。     

Progress in Synthesis，Detection and Clinical Application of Posaconazole北大核心CSCD

Posaconazole,as the second generation of triazole antifungal drugs,has a wide antifungal spectrum and strong antibacterial activity. It is widely used in clinical practice. However,it has been eight years since its publication before it is approved in China. In order to better understand posaconazole,a first-line drug with great clinical demand, this paper summarizes the pharmacokinetics, pharmacological properties,clinical application and synthetic route of posaconazole in the literature at home and abroad. It is hoped that it can fill the gap in the domestic API market,break the current situation that the API is completely dependent on import,and provide a useful reference for the industrial R & D. © 2022, Science Press (China). All rights reserved.     

Research on Performance Decay Mechanism of Pt/C Catalyst in Long-Term ORR Test北大核心CSCD

In proton exchange membrane fuel cells,cost,performance and durability are important issues that are need to be resolved before commercialization. The main reason for fuel cell performance degradation during operation is the loss of electrochemical surface area during long-term aging or transient. These losses mainly come from the degradation of the catalyst metal and the corrosion of the carbon support. This is a continuous and irreversible process that will greatly shorten the service life of the fuel cell. In order to explore this problem,20%（mass fraction）Pt/C catalyst is prepared based on carbon carrier etched by sulfuric acid. The morphology characterization test shows that it is uniformly dispersed and uniform in particle size,which is considered as an excellent material for long-term oxygen reduction （ORR） stability test. Next,the ORR stability test method with different cyclic voltammetry （CV） cycles is used to observe its performance degradation,and a series of physical characterizations,e. g. transmission electron microscopy（TEM）,high-resolution electron microscopy（HRTEM）,X-ray photoelectron spectroscopy（XPS）and Raman spectroscopy （Raman）,are used to further intuitively analyzed the attenuation mechanism. It is reported that the reasons for the degradation of the stability of Pt/C catalysts are mainly from the dissolution,agglomeration,oxidation and migration of Pt particles and the corrosion of carbon supports. This study elucidates the source of the impact on the stability of fuel cells during operation,and provides a reference for designing high-stability commercial ORR catalysts. © 2022, Science Press (China). All rights reserved.     

Research progress of the retrospective detection of organophosphorus nerve agent exposure using point-of-care testing techniqueEI北大核心CSCD

有机磷神经性毒剂(OPNA)是一类速杀性化学战剂,人员中毒后通过溯源检测来确定OPNA种类和剂量对于毒剂使用指证和人员救治非常重要。当前大部分溯源检测方法灵敏度高、特异性好,但因依赖大型设备限于实验室,不便于现场检测。随着现场快速检测(POCT)技术的发展和新识别分子的开发,大量OPNA中毒溯源现场检测技术被建立和应用。本文主要基于胆碱酯酶活性抑制、特异性识别和直接生化反应原理从3方面分析总结了OPNA中毒溯源POCT技术的研究进展和应用,展望了其未来发展趋势。     

Progress in Molecular Dynamics and Hansen Solubility Parameters of Low Molecular Weight Gels北大核心CSCD

Recently,the use of computational methods such as Molecular Dynamics（MD）simulations and Hansen Solubility Parameters （HSPs）to study the behavior of small molecule gelators has attracted much attention. MD simulation is a computational method based on classical mechanics and is one of the preferred techniques for understanding the process of small molecule gelators. The MD simulation can more accurately analyze the gelation trend or assembly behavior of small molecule gelators,dynamically and graphically display the self-assembly process,effectively reveal the relationship between the structure of small molecule gelators and related gelation behavior,and quantitatively analyze non-covalent bond interactions such as hydrogen bonds,π-π stacking,van der Waals interactions,ionic bonding and solvophobic interactions. By performing molecular dynamics simulations on known gelators/non-gelators,parameters related to gelation behavior in the simulated data are extracted,and the linear correlation is measured by fitting the Pearson correlation coefficient to finally predict the gelation behavior of a certain class of small molecules. On the other hand,the empirical model developed according to the HSPs is the most representative,which consists of the energy of dispersion interaction（δd）,the energy of polar interaction（δp）and H-bonding energy（δh ）between molecules. These three parts determine the coordinate point of the three-dimensional space（Hansen space）. According to the range of the point,it can be determined whether the organic small molecule can form a gel in a specific solvent. In this paper,representative works published recently in the field of organic small molecule gels by using MD simulations and empirical models are reviewed. Some comments on the assembly behavior of gelators,the regulation and prediction of non-covalent bond interactions on gelation ability are made. © 2022, Science Press (China). All rights reserved.     

Study on the Uniformity of Microgrooves in Through-Mask Electrochemical Micromachining with Moving Cathode北大核心CSCD

As a typical surface texture, microgrooves have broad prospects in the fields of mechanical engineering, bio-medicine, new energy and efficient heat dissipation of electronic products. Through-mask electrochemical micromachining (TMEMM) is widely used in the fabrication of micro-structures because of high processing efficiency and no residual stress. However, due to the edge effect of current distribution, there is often a serious dimension discrepancy problem in electrochemical machining of micro-structures. In order to weaken the influence of edge effect on the uniformity of microgrooves, the method that TMEMM with a moving cathode is presented. The current distribution in the electrochemical machining is constantly changed by the movement of the cathode. Thus, the uniformity of the micro-structure is improved. The method is studied through the combination of simulation and experimental verification. Firstly, the electrochemical machining process of TMEMM was analyzed theoretically. The theoretical analysis results show that the depth of electrolytic etching is proportional to the current density of electrolytic machining. To change the uniformity of the electrochemical machining, the most important thing is to improve the uniformity of the current distribution. On this theoretical basis, the current distribution and anodic contour of microgroove array during TMEMM are simulated by using the COMSOL finite element analysis software. The simulation results indicate that, compared with the conventional TMEMM, the TMEMM with moving cathode can obtain the microgrooves array with more uniform size. Secondly, on the basis of numerical simulation, the TMEMM experiment was carried out. The experimental results indicate that the TMEMM method of moving cathode can effectively improve the size uniformity of microgroove array. It can be observed by microscope that the microgroove array obtained by TMEMM with a moving cathode had good structural morphology and higher uniformity. Compared with conventional TMEMM, the uniformity of TMEMM with moving cathode has been improved by 68.3%. At the same time, under different experimental conditions, the trend of unevenness of microgroove array was calculated. With the increase of the distance between the cathode and anode, the microgroove depth heterogeneity showed a tendency of first decreasing and then increasing, when the distance between anode and cathode is about 1.3 mm, the unevenness of microgroove array reaches the minimum point. With the increases of cathode width and cathode speed, the depth inhomogeneities of microgroove increase and decrease gradually, respectively. The simulation results are basically consistent with the experimental results. It can be seen that the TMEMM with the moving cathode method can greatly improve the size uniformity. © 2021 Authors. All rights reserved.     

人参连作土壤对不同生育期人参生长发育及抗氧化系统的影响

人参产业是吉林省的特色支柱健康产业,但由于人参连作障碍的限制,使得人参产业面临着资源枯竭。通过探究人参连作土壤对正常人参生长发育的影响,研究破解人参连作障碍。以正常生长的盆栽人参样本为对照组（Control Check, CK）,以连作土壤种植人参样本为模型组（Continuous Crop obstacles, CCO）,从植物组织形态、生理生化水平和组织内抗氧化水平等3个方面,系统分析了不同生长时期连作土壤对正常人参生长发育的影响。结果表明,CCO组人参植株的株高、主根长、须根数在采收期较CK组相比具有显著差异（P<0.05）。在果实期和采收期,CCO组样本组织内过氧化氢酶（CAT）活性显著降低,丙二醛（MDA）含量显著增加（P<0.05）;在采收期,与CK组比较,CCO组人参过氧化物酶（POD）的活性显著增加（P<0.05）,超氧化物歧化酶（SOD）活性显著降低（P<0.05）,表明人参连作土壤可显著影响对正常人参植株的氧化应激水平与生长发育两个方面,如果能够通过土壤改良的方法,破解连作难题,则将有效解决吉林省的人参种植领域瓶颈问题。     

人参栽培研究进展

人参作为经济作物在中国有着数千年的种植历史。人参具有多种药理活性,在食品、医药和化妆品等领域有着广泛的应用。然而,目前人参的实际产量并不能满足市场需求。提升人参生产效率仍是当前阶段人参种植研究工作的首要目标。近些年,在人参选地、种子处理、播种、搭棚、培育和采收等生产环节中,涌现了许多新模式、新技术、新方法和新仪器。本文从栽培模式和技术角度综述人参栽培的研究现状,希望为进一步提升人参生产效率提供参考。     

近红外光谱技术定量分析连作滁菊土壤中的阿魏酸含量

应用近红外光谱(NIRS)技术定量分析连作滁菊土壤样品中阿魏酸的含量.通过标准杠杆值、学生残差和马氏距离判断异常光谱,经二阶导数和Norris平滑滤噪预处理后,在6000~4000 cm-1范围,最佳因子数为7,采用偏最小二乘法(PLS)构建数学模型.结果表明,模型校正集和验证集与高效液相色谱仪(HPLC)测定的参考值之间均呈现良好相关关系,校正相关系数Rc为0.9914,交叉验证相关系数Rcv为0.9935,校正集误差均方根(RMSEC)为0.484,预测误差均方根(RMSEP)为0.539,交叉验证误差均方根(RMSECV)为0.615.研究结果表明,NIRS分析技术能够实现连作土壤中阿魏酸的快速检测,结果准确可靠.     

连续流动注射法测定土壤和植物中全磷

应用AA3型连续流动分析仪测定了土壤和植物中全磷.结果表明:对于采用高氯酸-硫酸消解的土壤样品以及硫酸-过氧化氢消解的植物样品,在测定时调节反应混合液的酸度使其在显色的适宜范围内,磷的质量浓度在6 mg·L-1(土壤)和7.5 mg·L-1(植物)以内呈线性,相关系数分别为0.999 2(土壤)和0.999 6(植物);加标回收率98.5%～100.5%,相对标准偏差小于2%,检出限分别为0.010 mg·L-1(土壤)和0.013 mg·L-1(植物).     

土壤中砷形态分析研究进展

本文评述了近年来国内外土壤中砷形态分析的主要研究方法,包括联用分析法、分级提取法和同步辐射X-射线线吸收光谱法。联用分析法包括气相色谱联用法、毛细管电泳联用法和高效液相色谱联用法。重点介绍了目前应用范围较广的高效液相色谱-等离子体质谱(HPLC-ICP-MS)联用法和高效液相色谱-氢化物发生-原子荧光光谱(HPLC-HG-AFS)联用法。同步辐射X-射线线吸收光谱法近几年发展迅速,是最具发展潜力的形态分析方法。     

土壤腐殖质的分析化学研究进展

对土壤腐殖质的分析化学研究进展作了综述。具体包含如下几个方面的内容；土壤腐殖质的组成和结构的研究，土壤腐殖质的起源和形成的研究，土壤腐殖质与土壤中有机，无机物质的相互作用的研究以及有机物料的分解，转化及其对腐殖质影响的研究，同时，对土壤腐殖质的研究中有待进一步用分析化学方法解决的几个问题进行了探讨。     

人参属中药腐解化感作用研究进展

人参、西洋参和三七为人参属近缘物种,形态和化学成分相似,均具有连作障碍的特性。人参属中药连作后,土壤环境逐渐变得不适宜其生长,植株长势变弱易患病,导致生长发育受到抑制,出现严重的根腐病、须根脱落,甚至植株死亡现象。而造成人参属连作障碍的主要原因之一是化感物质的自毒作用,人参残体降解物作为人参化感物质主要来源之一,会导致种子发芽率下降,种苗死亡率升高、根腐病等病害加重,最终造成连作障碍。在人参属中药连作过程中,通过化感物质与土壤交流,也会直接或间接影响土壤理化性质的变化。对人参属中药腐解化感作用的研究进展以及腐解对土壤成分的影响进行综述,以期为人参属中药腐解化感作用及土壤利用的相关研究提供借鉴。     

Chemical Fractionations of Lead and Zinc in the Contaminated Soil Amended with the Blended Biochar/Apatite

Heavy metal contamination in agricultural land is an alarming issue in Vietnam. It is necessary to develop suitable remediation methods for environmental and farming purposes. The present study investigated the effectiveness of using peanut shell-derived biochar to remediate the two heavy metals Zn and Pb in laboratory soil assays following Tessier’s sequential extraction procedure. The concentration of heavy metals was analyzed using Inductively coupled plasma mass spectrometry (ICP-MS). This study also compared the effectiveness of the blend of biochar and apatite applied and the mere biochar amendment on the chemical fractions of Pb and Zn in the contaminated agricultural soil. Results have shown that the investigated soil was extremely polluted by Pb (3047.8 mg kg⁻¹) and Zn (2034.3 mg kg⁻¹). In addition, the pH, organic carbon, and electrical conductivity values of amended soil samples increased with the increase in the amendment’s ratios. The distribution of heavy metals in soil samples was in the descending order of carbonate fraction (F2) > residue fraction (F5) > exchangeable fraction (F1) > Fe/Mn oxide fraction (F3) > organic fraction (F4) for Pb and F5 ≈ F2 > F1 > F3 > F4 for Zn. The peanut shell-derived biochar produced at 400 °C and 600 °C amended at a 10% ratio (PB4:10 and PB6:10) could significantly reduce the exchangeable fraction Zn from 424.82 mg kg⁻¹ to 277.69 mg kg⁻¹ and 302.89 mg kg⁻¹, respectively, and Pb from 495.77 mg kg⁻¹ to 234.55 mg kg⁻¹ and 275.15 mg kg⁻¹, respectively, and immobilize them in soil. Amending the biochar and apatite combination increased the soil pH, then produced a highly negative charge on the soil surface and facilitated Pb and Zn adsorption. This study shows that the amendment of biochar and biochar blended with apatite could stabilize Pb and Zn fractions, indicating the potential of these amendments to remediate Pb and Zn in contaminated soil.     

贮氢材料研究进展

氢作为一种新的能源,受到各国政府和科学家的极大重视,其制备、贮存、输运及应用技术有了迅速的发展。本文综述贮氢材料的种类及其最近研究进展,并对最近发展起来的一些合金贮氢材料和碳质贮氢材料的制备方法作了介绍。     

羟基磷灰石表面改性的研究进展

羟基磷灰石（HAP）由于其良好的生物相容性及骨诱导作用而被广泛应用于生物复合材料中。但是,其本身容易聚集,与聚合物之间相容性差,会导致复合材料的力学性能和生物学性能下降。在HAP表面改性既可以有效防止颗粒间的聚集,增强其与基体间的相互作用,同时,还可以通过接上具有特殊功能的聚合物,赋予HAP新的用途。本文综述了羟基磷灰...