Technical Study on Extraction of Procyanidins in Lycium ruthenicum Murr. Using Sub-critical Fluid 1,1,1,2-Tetrafluoroethane( R134a)and Content Determination from Different Producing Areas

[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction rate of procyanidins as an indicator,the influence of pressure,temperature,and extraction time on extraction rate of procyanidins fromL. Ruthenicum Murr. was studied by single factor experimental methods and orthogonal array design. [Results]The order of factors affecting extraction rate of procyanidins was extraction temperature > extraction pressure > extraction time. The optimum extraction conditions were as follows: the extraction rate of procyanidins fromL. ruthenicum Murr. was the highest with extraction pressure of 1. 2 MPa,extraction temperature of 50℃ and extraction time of 90 min. The content of procyanidins in L. ruthenicum Murr. from different producing areas was determined by vanillin-HCl method under the optimal conditions. [Conclusions] The method has the advantages of easy operation,good selectivity,low extraction temperature and high extraction efficiency,which is suitable for extraction of procyanidins in L. ruthenicum Murr.

Mott-Schottky异质结对金属电子态持续调控促进乙醇氧化C-C断裂

直接乙醇燃料电池的效率与阳极乙醇氧化反应(EOR)C1路径选择性密切相关,然而C-C键断裂的能垒较高,使得C1路径产物选择性低,从而限制了直接乙醇燃料电池效率的提升.设计具有高C-C裂解效率的电催化剂,对于构建高效直接乙醇燃料电池具有重要意义.本文报道了一种Mott-Schottky异质结调节催化活性中心电子状态从而促进EOR过程中C-C裂解的新策略.我们以PdAu合金纳米颗粒(NPs)为模型催化剂,制备了PdAu@N_(x)C金属-碳Mott-Schottky异质结构.PdAu NPs(15.9±1.9 nm)均匀地分散在N掺杂的碳载体上.我们通过在宽范围内调节N掺杂量,调控异质结界面电势,形成了不同程度的电荷分离.通过催化剂结构与性能研究,建立了反应活性与催化剂功函数之间的线性关系,表明金属/碳界面电子转移可以有效促进EOR.优化的催化剂PdAu@N10.69C,显示出高C1产物选择性(FE=51.1%),质量活性(MA=9.7 A mg Pd^(-1))和比活性(SA=13.2 mA cm^(-2)),优于PdAu@C和大多数报道的Pd基EOR催化剂.实验结果和理论计算表明,N的引入促进了电子由碳层向PdAu转移,加强了对*CH_(3)CO的吸附,从而提高了C-C键的断裂效率.这项工作为整流策略提高EOR性能提供了一种新的研究思路.

Thermal behavior of Mongolian low-rank coals during pyrolysis

Low temperature pyrolysis behavior of four low-rank coals from the biggest deposits of Mongolia were studied using a fixed-bed reactor and Gray-King retort.The coal samples and resultant chars were analyzed using Fourier transform infrared spectroscopy(FTIR),^(13)C nuclear magnetic resonance(^(13)C NMR)to explore the structure changes and thermogravimetric analyzer coupled with mass spectrometry(TG-MS)was used to investigate the pyrolysis reactivity of coal during thermal decomposition process.The results showed that the aliphatic structure in coal was significantly reduced and the carboxyl groups almost completely decomposed during pyrolysis process at 600℃.The tar yield of Gray-king test is higher than that obtained from the fixed-bed reactor.The gaseous evolution measured by TG-MS during pyrolysis showed that the maximum peaks of evolution of CH_(4),H_(2),C_(2)H_(2),C_(2)H_(5),CO,and CO_(2) gases were well corresponded to the maximum rate of weight loss in the range 428-445℃.

Deformable double-shelled hollow mesoporous organosilica nanocapsules:A multi-interfacial etching strategy

Multishelled hollow structures have drawn increasing interest because of their peculiar compartmentation environments and physicochemical properties.In this work,deformable double-shelled hollow mesoporous o rganosilica nanocapsules(DDHMONs)were succes s fully synthesized by a multi-interfacial etching strategy.The obtained DDHMONs have a double-shelled structure with aninorganic-organic hybrid framework,a uniform outer layer(~320 nm)and inner layer(~180 nm),ordered mesochannels(~2.21 nm),and a large specific surface area(~1233 m^(2)/g).In vitro toxicity tests show that the DDHMONs have excellent biocompatibility when coincubated with human breast cancer cells.In addition,the anti cancer substance doxorubicin(DOX)can be highly loaded in DDHMONs(~335μg/mg).The results from flow cytometry together with confocal laser scanning microscopy show that DOX can be efficiently delivered into MCF-7 cells by DDHMONs,thus improving chemotherapeutic efficiency and demonstrating that DDHMONs have potential nanomedicine applications as anticancer agents.

Uptrend of the Western North Pacific Tropical Cyclone Outflow Height during 1959-2021

Relatively little is known about the impact of global warming on the tropical cyclone(TC)outflow,despite its large contribution to TC intensity.In this study,based on the International Best Track Archive for Climate Stewardship(IBTrACS)dataset and ERA5 reanalysis data,we show that the TC outflow height has risen significantly(48.20±22.18 m decades-1)in the past decades(1959-2021)over the western North Pacific,and the rising trend tends to be sharper for stronger TCs(the uptrend of severe typhoon is 61.09±40.92 m decades-1).This rising trend of the outflow height explains the contradiction between the decrease trend of the TC outflow temperature and the increase trend of the atmospheric troposphere temperature.Moreover,possible contribution of the TC outflow height uptrend to TC intensity has also been investigated.The results show that the rise of outflow height leads to the decrease of outflow temperature,and thus an increased difference between underlying sea surface temperature(SST)and TC outflow temperature,which eventually favors the increase of TC intensity.