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Selective nitration of phenols using bismuth subnitrate/charcoal in the presence of trichloroisocyanuric acid under aprotic conditions

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Chinese Chemical Letters 2010年第11期21卷 1283-1286页

作者： Ali Reza Pourali Fatemeh Fatemi School of Chemistry Damghan University of Basic Sciences

A mild,efficient and regioselective method for the mononitration of phenolic compounds is described using bismuth subnitrate/ charcoal in the presence of trichloroisocyanuric acid in CH2Cl2 at room temperature.

关键词： Nitration Phenol Bismuth subnitrate Supported reagent

Characteristics of CO_2 sequestration in saline aquifers

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Petroleum Science 2010年第1期7卷 83-92页

作者： Yang Fang Bai Baojun Tang Dazhen Shari Dunn-Norman David Wronkiewicz School of Energy Resources China University of Geosciences Beijing 100083 China Department of Geological Sciences and Engineering Missouri University of Science and Technology Rolla MO 65401USA

Storage of CO2 in saline aquifers is a viable option for reducing the amount of CO2 released to the atmosphere. This paper provides an overall review of CO2 sequestration in saline aquifers. First, the principles of CO2 sequestration are presented, including CO2 phase behavior, CO2-water-rock interaction, and CO2 trapping mechanisms. Then storage capacity and CO2 injectivity are discussed as the main determinants of the storage potential of saline aquifers. Next, a site section process is addressed considering basin characteristics, reservoir characteristics, and economic and social concerns. Three main procedures are then presented to investigate the suitability of a site for CO2 sequestration, including site screening, detailed site characterization, and pilot field-scale test. The methods for these procedures are also presented, such as traditional site characterization methods, laboratory experiments, and numerical simulation. Finally, some operational aspects of sequestration are discussed, including well type, injection rate, CO2 purity, and injection strategy.

关键词： CO2 sequestration saline aquifer site selection screening criteria geological storage storage capacity

Formation of macroporous gel morphology by phase separation in the silica sol-gel system containing nonionic surfactant

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Journal of University of Science and Technology Beijing 2005年第6期12卷 564-571页

作者： Junsheng Wu Xiaogang Li Wei Du Hua Chen Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The phase separation and gel formation behavior in an alkoxy-derived silica sol-gel system containing C16EO15 has been investigated. Various gel morphologies similar to other sol-gel systems containing organic additives were obtained by changing the preparation conditions. Micrometer-range interconnected porous gels were obtained by freezing transitional structures of phase separation in the sol-gel process. The dependence of the resulting gel morphology on several important reaction parameters such as the starting composition, reaction temperature and acid catalyst concentration was studied in detail. The experimental results indicate that the gel morphology is mainly determined by the time relation between the onset of phase separation and gel formation.

关键词： silica sol-gel phase separation macroporous gel morphology nonionic surfactant

High-Entropy Spinel Oxide Nanofibers as Catalytic Sulfur Hosts Promise the High Gravimetric and Volumetric Capacities for Lithium–Sulfur Batteries

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Energy & Environmental Materials 2022年第2期5卷 645-654页

作者： Liyuan Tian Ze Zhang Sheng Liu Guoran Li Xueping Gao Institute of New Energy Material Chemistry School of Materials Science and EngineeringRenewable Energy Conversion and Storage CenterNankai UniversityTianjin 300350China

The exploration of new catalytic hosts is highly important to tackle the sluggish electrochemical kinetics of sulfur redox for achieving high energy density of lithium–sulfur ***,for the first time,we present high-entropy oxide(HEO,(Mg_(0.2)Mn_(0.2)Ni_(0.2)Co_(0.2)Zn_(0.2))Fe_(2)O_(4))nanofibers as catalytic host of *** HEO nanofibers show a synergistic effect among multiple metal cations in spinel structure that enables strong chemical confinement of soluble polysulfides and fast kinetics for polysulfide ***,the S/HEO composite displays the high gravimetric capacity of 1368.7 mAh g^(−1) at 0.1 C rate,excellent rate capability with the discharge capacity of 632.1 mAh g^(−1) at 5 C rate,and desirable cycle ***,the S/HEO composite shows desirable sulfur utilization and good cycle stability under a harsh operating condition of high sulfur loading(4.6 mg cm^(−2))or low electrolyte/sulfur ratio(5μL mg^(−1)).More impressively,the high volumetric capacity of 2627.9 mAh cm^(−3) is achieved simultaneously for the S/HEO composite due to the high tap density of 1.92 g cm^(−3),nearly 2.5 times of the conventional sulfur/carbon ***,based on high-entropy oxide materials,this work affords a fresh concept of elevating the gravimetric/volumetric capacities of sulfur cathodes for lithium–sulfur batteries.

关键词： catalytic host high-entropy oxide lithium-sulfur battery polysulfide conversion spinel oxide nanofibers

Synthesis of two mono-deoxy β-cyclodextrin derivatives as useful tools for confirming DIBAL-H promoted bis-de-O-methylation mechanism

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Chinese Chemical Letters 2012年第12期23卷 1315-1318页

作者： Su Long Xiao De Min Zhou Ming Yang Fei Yu Li He Zhang Pierre Sinay Yong Min Zhang State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking University Institut Parisien de Chimie Moleculaire UMR CNRS 7201Universite Pierre et Marie Curie-Paris 64 Place Jussieu Institute for Interdisciplinary Research Jianghan UniversityWuhan Economic and Technological Development Zone

Diisobutylaluminium hydride （DIBAL-H） promotes secondary rim regioselective bis-de-O-methylation of permethylated β- cyclodextrin （β-CD） to give diol 2. To gain an insight into the mechanism of this remarkable regioselective behavior, two corresponding permethylated β-CDs with an alcohol function at either 2- or 3-position were synthesized in our previous study. As a step further to this work, the two compounds were subjected to deoxygenation reaction with tributyltin hydride in the present of 2,2＇- azobisisobutyronitrile affording the corresponding 2- and 3-deoxy permethylated β-CD derivatives （19 and 16）. The structures of these two compounds were characterized by 1D and 2D NMR and HRMS. Compounds 16 and 19 were unable to react with DIBAL- H which suggests that O-2A and O-3B are necessary for DIBAL-H promoted bis-de-O-methylation reaction of permethylated β-CD.

关键词： Cyclodextrin (CD) DIBAL-H Deoxy Synthesis Mechanism

A comprehensive layered approach for implementing internet of things-enabled smart grid:A survey

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Digital Communications and Networks 2022年第3期8卷 388-410页

作者： Zahra Alavikia Maryam Shabro Electric Power Utility(EPU)Digital Transformation Center Niroo Research Institute(NRI)TehranIran

The current power grid confronts severe challenges in satisfying customers'*** transition to the much more flexible power grid enriched with renewable energies,micro-grid,and distributed energy resources has been considered as a straightforward solution to the customers’high *** smart equipment and renewable energies,electric power generation and storage through the power grid domains will be facilitated,which enables bi-directional energy and information *** power grid with such enhanced features is called Smart Grid(SG).Controlling and managing the diverse sets of variables in the SG requires precise measuring,monitoring,communicating,and analytic systems which increase the complexity of the *** complexity is the main barrier to the realization of the SG up to *** emergence of the Internet of Things(IoT)simplifies monitoring,communications,and data processing among smart things to connect to anything in the *** motivates the SG stakeholders and researchers to proceed with the best way to exploit the IoT technologies in the *** this survey paper,we summarize various efforts in this regard to highlight the advantages of the IoT-enabled SG and its probable *** this end,a comprehensive layered approach has been proposed in this paper to classify various applications of the IoT technologies in the *** IoT opportunities in each architecture layer facilitates the role of each technology and its relationship with other ***,open issues and future measures for the realization of IoT-enabled SG have been discussed in the paper.

关键词： Smart grid(SG) Internet of things(IoT) Layered approach Open issues

Electric Field-induced Conformational Transition of Bovine Serum Albumin from α-helix to β-sheet

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Chinese Chemical Letters 2000年第2期11卷 149-152页

作者： Yong Chun ZHU Guang Jin CHENG Shao Jun DONG (Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry,Chinese Academy of Sciences, Changchun 130022) Lab. of Electroanalytical Chemistry Changchun Inst. of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

The irreversible conformational transition of bovine serum albumin (BSA) from α-helix to β-sheet, induced by electric field near the electrode surface, was monitored by circular dichroism (CD) with a long optical pa... 详细信息

关键词： Bovine serum albumin conformational transition circular dichroism.

High-Entropy Alloys to Activate the Sulfur Cathode for Lithium-Sulfur Batteries

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Energy & Environmental Materials 2023年第3期6卷 40-49页

作者： Zhenyu Wang Hailun Ge Sheng Liu Guoran Li Xueping Gao Institute of New Energy Material Chemistry School of Materials Science and EngineeringRenewable Energy Conversion and Storage CenterNankai UniversityTianjin 300350China

Sulfur element possesses an ultrahigh theoretical specific capacity,while the utilization of sulfur in the whole cathode is lower obviously owing to the sluggish kinetics of sulfur and discharged products,limiting the enhancement on energy density of lithium-sulfur ***,for the first time,Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy is introduced as the core catalytic host to activate the electrochemical performance of the sulfur cathode for lithium-sulfur *** is manifested that Fe_(0.24)Co_(0.26)Ni_(0.10)Cu_(0.15)Mn_(0.25)high-entropy alloy nanocrystallites distributed on nitrogen-doped carbon exhibit high electrocatalytic activity toward the conversion of solid sulfur to solid discharged products across soluble intermediate lithium *** particular,benefiting from the accelerated kinetics by high-entropy alloy nanocrystallites and synergistic adsorption by nitrogen-doped carbon,the cathode exhibits high reversible capacity of 1079.5 mAh g_(-cathode)^(-1)(high utilization of 89.4%)with the whole cathode as active material,instead of sulfur ***,under both lean electrolyte(3μmg^(-1))and ultrahigh sulfur loading(27.0 mg cm^(-2))condition,the high discharge capacity of 868.2 mAh g_(-cathode)^(-1)can be still achieved for the sulfur *** strategy opens up a new path to explore catalytic host materials for enhancing the utilization of sulfur in the whole cathode for lithium-sulfur batteries.

关键词： catalytic host electrochemical performance high-entropy alloy lithium–sulfur batteries sulfur cathode

Effect of addition of inulin and fenugreek on the survival of microencapsulated Enterococcus durans 39C in alginate-psyllium polymeric blends in simulated digestive system and yogurt

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Asian Journal of Pharmaceutical Sciences 2015年第4期10卷 350-361页

作者： Babak Haghshenas Yousef Nami Minoo Haghshenas Abolfazl Barzegari Simin Sharifi Dayang Radiah Rozita Rosli Norhafizah Abdullah Institute of Biosciences University Putra Malaysia43400 UPM SerdangSelangorMalaysia School of Medicine Shahid Beheshti University of Medical SciencesTehranIslamic Republic of Iran Tabriz University of Medical Sciences Molecular Medicine and Therapy LabResearch Center for Pharmaceutical NanotechnologyTabrizIslamic Republic of Iran Chemical and Environmental Engineering Department Faculty of EngineeringUniversity Putra Malaysia43400 UPM SerdangSelangorMalaysia

The use of biopolymers for probiotic microencapsulation has been investigated in this *** objectives are to enhance its survival rate,colonic release,and stability of these probiotic cultures in digestive condition during storage *** types of biopolymers(alginate-psyllium)blend with different concentration of prebiotic;(inulin or fenugreek)were used as candidate for microencapsulation *** strain of probiotic candidates,namely;Enterococcus durans 39C was used in this *** microencapsulation of this strain with the respective polymer blend was performed by using a simple extrusion *** blend of formulations have recorded high encapsulation efficiency at value>98%.The survival rate of viable probiotic cells under simulated digestive conditions was also high with value above 47%as compared to non-microencapsulated *** nine gel formulations also displayed the high survival rate of viable probiotic cells during storage time(28 d).Their release occurred after 2 h in colonic condition and sustained until 12th h of incubation *** increase of prebiotic effect value added was observed in incorporated inulin and fenugreek *** short,this study revealed that a new herbal-based psyllium and fenugreek polymers have suitable potential as a matrix for probiotic microencapsulation.

关键词： Microencapsulation Psyllium Fenugreek Probiotic Enterococcus durans 39C