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Microcalorimetric investigation of the effect of berberine alkaloids from Coptis chinensis Franch on Staphylococcus aureus growth

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Science China Chemistry 2008年第7期51卷 640-645页

作者： YAN Dan XIAO XiaoHe JIN Cheng dong xiaoping Institute of Chinese Medicine 302 Hospital of People’s Liberation ArmyBeijing 100039China Chengdu University of Traditional Chinese Medicine Chengdu 610075China

The inhibitory effects of three berberine alkaloids (BAs) from rhizome of Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Staphylococcus aureus growth were investigated by mi- crocalorimetry. The power–time curves of S. aureus with and without BAs were acquired; meanwhile the extent and duration of inhibitory effects on the metabolism were evaluated by studying the growth rate constant (k), half inhibitory ratio (IC50), maximum heat-output power (Pmax), peak time of maximum heat-output power (tp) and total heat production (Qt). The value of k of S. aureus in the presence of the three BAs decreased with the increasing concentrations of BAs. Moreover, Pmax was reduced and the value of tp increased with increasing concentrations of the three drugs. The inhibitory activity varied with different drugs. The values of IC50 of the three BAs are respectively, 101.4 μg/mL for berberine, 241.0 μg/mL for palmatine and 792.3 μg/mL for jateorrhizine. The sequence of antimicrobial activity of the three BAs is: berberine > palmatine > jateorrhizine. It is suggested that the functional group me- thylenedioxy or methoxyl at C2 on the phenyl ring could possibly improve antimicrobial activity more strongly than hydroxyl at C2 on the phenyl ring.

关键词： berberine alkaloid microcalorimetry Staphylococcus aureus inhibitory effect

Need of Practical Strategy for Improving Awareness of Acceptance of Tuberculosis Preventive Treatment among the Public and the Healthcare Workers

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Biomedical and Environmental Sciences 2024年第11期37卷 1233-1234页

作者： xiaoping dong National Key-Laboratory of Intelligent Tracking and Forecasting for Infectious Disease National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China

Since the emergence of COVID-19 in 2020,the threaten of emerging infectious diseases(EIDs)has attracted great attentions and echoes either from professional institutions,governments or *** conceptualization of“Disease X”,which covers more than 30 families of viruses,has strongly actuated various resources into the development of medical countermeasures and the research across all families of *** the other hand,the endemic even pandemic old communicable diseases,such as tuberculosis(TB),malaria,HIV/AIDS,etc.,should never be *** in 2023,the estimated TB cases was 10.8 million and the estimated deaths was 1.25 million according to the Global Tuberculosis Report 2024 by World Health Organization(WHO)[1].The most affected countries are India,Indonesia,China,the Philippines,Pakistan,Nigeria,Bangladesh,and the Democratic Republic of the Congo.

关键词： Tuberculosis neglected Strategy

Rheological behavior of PMVE-MA aqueous solution with metallic cations

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Frontiers of Chemical Science and Engineering 2011年第1期5卷 126-130页

作者： xiaoping dong Li LI Jun XU Xuhong GUO State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

The rheological properties of aqueous solutions of poly(methyl vinyl ether-co-maleic anhydride)(PMVE-MA)upon addition of metallic cations at different pH values were ***-gel transition and shearthickening phenomena at moderate shear rate were observed upon increasing the amount of metallic cations,especially for cupric *** certain molar ratio(fgel)of added cupric cations to carboxyl groups in PMVE-MA,the system became gel-like,and the storage modulus(G′)and loss modulus(G′′)were parallel and exhibited a power-law dependence on the frequency,which is consistent with Winter’s hypothesis of determining the gel point of a crosslinking *** shear-thickening behavior depends on fgel,pH,metallic valence,and temperature.

关键词： poly(methyl vinyl ether-co-maleic anhydride) shear-thickening gel point rheology

Effects of rapid quenching on structure and cycle stability of La-Mg-Ni-Co type hydrogen storage alloy

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Rare Metals 2006年第z1期25卷 207-212页

作者： dong xiaoping Lü Fanxiu ZHANG Yanghuan YANG Liying FENG Meng WANG Xinlin School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Mateials Inner Mongolia University of Science and Technology Baotou 01401 China School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China

In order to improve the cycle stability of La-Mg-Ni-Co type alloy electrode, rapid quenching technology was employed. The effects of rapid quenching on the microstructure and cycle stability of the alloy were investigated. The obtained results show that the La2Mg(Ni0.85Co0.15)9M0.1 (M=B, Cr) alloy electrodes are composed of (La, Mg)Ni3 phase, LaNi5 phase and a small amount of the LaNi2 phase. A trace of the Ni2B phase exists in the as-cast MB alloy, and the Ni2B phase in the alloy nearly disappears after rapid quenching. Rapid quenching technology can slightly improve the cycling life of the alloy. When the quenching rate increases from 0 m·s-1 (As-cast is defined as quenching rate of 0 m·s-1) to 30 m·s-1, the cycle lives of the MB, MCr alloys enhance from 86 and 87 cycles to 106 and 119 cycles, respectively. On the other hand, the average capacity decay rates of the MB, MCr alloys decrease from 1.7172 and 1.7178 mAh·g-1·cycle-1 to 1.5751 and 1.3060 mAh·g-1·cycle-1 after 86 charge-discharges cycling, respectively.

关键词： rapid quenching La-Mg-Ni-Co type hydrogen storage alloy structure characteristics cycle stability

Comparative study on the hydrogen storage performance of as-milled MgRENi rapid quenched alloy catalyzed by metal sulfides

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Journal of Magnesium and Alloys 2024年第5期12卷 2010-2023页

作者： xiaoping dong Zhaoqing Zhang Liying Yang Shenghai Xin Dandan Su Zhiyuan Li Department of Mechanical Design and Manufacture and Automation Hebei UniversityBaoding 071000PR China Baoding New Energy Vehicle Power Engineering Technology Research Center Hebei UniversityBaoding 071002PR China Hebei Technology Innovation Center for Lightweight of New Energy Vehicle Power System(Preparation) Hebei UniversityBaoding 071002PR China

The composites of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)as-quenched alloy and 3 wt.%M(M=CoS,CoS_(2),MoS_(2))catalyst were prepared by high-speed vibration ball *** effects of metal sulfides on the hydrogenation and dehydrogenation dynamics of alloys were *** results show that the as-milled composites contain a large number of amorphous embedded by a small amount of nanocrystals,and there are many point *** ball milling,the crystal grain size in the composites containing CoS is relatively larger,followed by CoS_(2)and MoS_(2)*** hydrogenation,the amorphous phase is crystallized to form Mg_(2)NiH_(4),YH_(3),Pr_(8)H_(18.96),Sm_(3)H_7,Mg,Co or Mo phases,however,Mg_(2)Ni,YH_(2),PrH_(2)and Ni_(3)Y phases appeared after *** maximum hydrogenation capacity of the composites containing CoS,CoS_(2)and MoS_(2)are 3.939,4.265 and 4.507 wt.%,*** hydrogenation saturation ratio of composite containing MoS_(2)is higher than that of the composites containing CoS and CoS_(2).The dehydrogenation activation energy of the composites containing CoS,CoS_(2)and MoS_(2)is 107.76,68.43 and 63.28 ***^(-1).H_(2).On the improvement of hydrogen storage performance of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)alloy,the catalytic effect of MoS_(2)sulfide is better than that of CoS_(2)sulfide,and which is better than CoS sulfide.

关键词： Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)as-quenched alloy CoS CoS_(2)and MoS_(2)sulfide Milling Activation energy Hydrogen storage dynamics

Effects of substituting Ni with M (M=Cu, Al and Mn) on microstructures and electrochemical characteristics of La-Mg-Ni system (PuNi_3-type) electrode alloys

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Rare Metals 2006年第z1期25卷 25-32页

作者： ZHANG Yanghuan ZHAO dongliang dong xiaoping REN Huiping GUO Shihai WANG Xinlin Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material Inner Mongolia University of Science and Technology Baotou 014010 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China School of Material University of Science and Technology Beijing Beijing 100083 China School of Material Inner Mongolia University of Science and Technology Baotou 014010 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China

In order to improve the electrochemical cycle stability of La-Mg-Ni system (PuNi3-type) hydrogen storage alloy, Ni in the alloys was partially substituted by M (M=Cu, Al, Mn). A new La-Mg-Ni system electrode alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Cu, Al, Mn; x=0, 0.1) were prepared by casting and rapid quenching. The effects of element substitution and rapid quenching on the microstructures and electrochemical performances of the alloys were investigated. The results by XRD, SEM and TEM show that the alloys have a multiphase structure, including the (La, Mg)Ni3 phase, the LaNi5 phase and the LaNi2 phase. The rapid quenching and element substitution have an imperceptible influence on the phase compositions of the alloys, but both change the phase abundance of the alloys. The rapid quenching significantly improves the composition homogeneity of the alloys and markedly decreases the grain size of the alloys. The Cu substitution promotes the formation of an amorphous phase in the as-quenched alloy, and a reversal result by the Al substitution. The electrochemical measurement indicates that the element substitution decreases the discharge capacity of the alloys, whereas it obviously improves the cycle stability of the alloys. The positive influence of element substitution on the cycle life of the alloys is in sequence Al>Cu>Mn, and negative influence on the discharge capacity is in sequence Al>Mn>Cu. The rapid quenching significantly enhances the cycle stability of the alloys, but it leads to a different extent decrease of the discharge capacity of the alloys.

关键词： element substitution rapid quenching La-Mg-Ni system electrode alloy microstructures electrochemical performances

Electrochemical Performance of Nanocrystalline and Amorphous Mg–Nd–Ni–Cu-Based Mg_2Ni-type Alloy Electrodes Used in Ni-MH Batteries

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1088-1098页

作者： Yanghuan Zhang Haitao Wang xiaoping dong Wengang Bu Zeming Yuan Guofang Zhang Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources Inner Mongolia University of Science and Technology Department of Functional Material Research Central Iron and Steel Research Institute College of Quality and Technical Supervision Hebei University

Nanocrystalline and amorphous Mg2Ni-type（Mg24Ni10Cu2）100–xNdx（x = 0, 5, 10, 15, 20） alloys were prepared by melt-spinning technology. The structures of as-cast and spun alloys were characterised by X-ray diffraction,scanning electron microscopy and transmission electron microscopy. Electrochemical performance of the alloy electrodes was measured using an automatic galvanostatic system. The electrochemical impedance spectra and Tafel polarisation curves of the alloy electrodes were plotted using an electrochemical work station. The hydrogen diffusion coefficients were calculated using the potential step method. Results indicate that all the as-cast alloys present a multiphase structure with Mg2 Ni type as the major phase with Mg6 Ni, Nd5Mg41 and Nd Ni as secondary phases. The secondary phases increased with the increasing Nd content. The as-spun Nd-free alloy exhibited nanocrystalline structure, whereas the as-spun Nd-doped alloys exhibited nanocrystalline and amorphous structures. These results suggest that adding Nd facilitates glass formation of Mg2Ni-type alloys. Melt spinning and Nd addition improved alloy electrochemical performance, which includes discharge potential characteristics, discharge capacity, electrochemical cycle stability and high-rate discharge ability.

关键词： Mg2Ni-type alloy Nd addition Melt spinning Structure Electrochemical performance

A comparison study of hydrogen storage properties of as-milled Sm_5Mg_(41) alloy catalyzed by CoS_2 and MoS_2 nano-particles

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Journal of Materials Science & Technology 2018年第10期34卷 1851-1858页

作者： Zeming Yuan Bangwen Zhang Yanghuan Zhang Shihai Guo xiaoping dong dongliang Zhao InstrumentalAnalysis Center Inner Mongolia University of Science and Technology Baotou 014010 China Department of Functional Material Research Central Iron and Steel Research Institute Beijing 100081 China Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources Inner Mongolia University of Science and Technology Baotou 014010China Department of Mechanical Engineering Hebei University Baoding 071002 China

The influences of the catalysts of CoS2 and MoB2 nano-particles on microstructure and hydrogen stor-age behaviors of as-milled SmsMg41 alloy have been compared in this work. The SmsMg41 ＋ 5 wt.% M （M = COS2, MoS2） alloys were prepared by milling the mechanical ground as-cast SmsMg41 alloy powders （particle size ≤75 μm） with 5 wt.% CoS2 or MoS2 nano-particles （particle size ≤ 30 nm）, respectively. The results demonstrate that the CoS2 and MoS2 nanoparticles are embedded into the alloy surface, which is nanostructure containing some crystal defects, such as dislocation, grain boundary and twin etc. Those microstructures play a beneficial role in reducing the total potential barrier that the hydrogen absorption or desorption reactions must overcome, hence improving the hydrogen storage kinetics of the alloys. The as-milled alloys are composed of SmsMg41 and SmMg3 phases, and ball milling refines their crys-tal grains. The MgH2 and Sm3H7 phases appear after hydrogenation, while Mg and Sm3H7 phases exist after dehydrogenation. The dehydriding activation energy of M = CoS2 and MoS2 alloys are 101.67 and 68.25 kJ/mol H2 respectively. The initial hydrogen desorption of M = CoS2 and MoS2 alloys are 252.9 ℃ and 247.8 ℃.The hydrogenation and dehydrogenation enthalpy changes of M = MoS2 alloy are a little smaller than that of MzCoS2 alloy. Therefore, the catalyst MoS2 can improve the as-milled SmsMg41 alloy in hydrogen storage property more effectively than C0S2.

关键词： SmsMg41 alloy CoS2 and MoS2 catalyst Milling Activation energy Hydrogen storage kinetics

Improved Hydrogen Storage Kinetics of Nanocrystalline and Amorphous Mg-Nd-Ni-Cubased Mg_2Ni-type Alloys by Adding Nd

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Journal of Wuhan University of Technology(Materials Science) 2015年第6期30卷 1115-1124页

作者：张羊换 ZHAI Tingting YANG Tai YUAN Zeming ZHANG Guofang dong xiaoping Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources Inner Mongolia University of Science and Technology Department of Functional Material Research Central Iron and Steel Research Institute College of Quality and Technical Supervision Hebei University

In order to improve the gaseous and electrochemical hydrogen storage kinetics of the M2Nitype alloy, the elements Cu and Nd were added in the alloy. The nanocrystalline and amorphous Mg2Ni-type alloys with the composition of（Mg24Ni10Cu2）100-xNdx（x = 0, 5, 10, 15, 20） were prepared by melt spinning technology. The effects of Nd content on the structures and hydrogen storage kinetics of the alloys were investigated. The characterization by X-ray diffraction（XRD）, transmission electron microscopy（TEM） and scanning electron microscopy（SEM） reveals that all the as-cast alloys hold multiphase structures, containing Mg2Ni-type major phase as well as some secondary phases Mg6Ni, Nd5Mg41, and Nd Ni, whose amounts clearly grow with increasing Nd content. Furthermore, the as-spun Nd-free alloy displays an entire nanocrystalline structure, whereas the as-spun Nd-added alloys hold a mixed structure of nanocrystalline and amorphous structure and the amorphization degree of the alloys visibly increases with the rising of the Nd content, suggesting that the addition of Nd facilitates the glass forming in the Mg2Ni-type alloy. The measurement of the hydrogen storage kinetics indicates that the addition of Nd significantly improves the gaseous and electrochemical hydrogen storage kinetics of the alloys. The addition of Nd enhances the diffusion ability of hydrogen atoms in the alloy, but it impairs the charge-transfer reaction on the surface of the alloy electrode, which makes the high rate discharge ability（HRD） of the alloy electrode fi rst mount up and then go down with the growing of Nd content.

关键词： Mg2Ni-type alloy Nd addition structures hydrogen storage kinetics