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关键词： Hybrid nanostructures   graphene–   alumina hybrid   sol–   gel   sonochemical graphene exfoliation   dodecylamine   oxygen-free graphene  

摘要： Combination of sol-gel and sonochemical techniques is suggested for producing a nanostructured graphene-alumina hybrid, which is a promising raw material for manufacturing fine-grained ceramics. This study focuses on the use of dodecylamine both in the sol-gel synthesis of Al-containing particles and in sonochemical graphene exfoliation. It has been shown that, when forming graphene-alumina composite in a reaction mixture of Al-containing sol and graphene suspension, graphene sheets take part as a template in the formation of a hybrid structure. Graphene sheets orient sol particles on their surface due to van der Waals interaction and control growth and direction of oligomeric gel chains. The graphene sheets limit the growth of Al-containing particles, which leads to an increase in the specific surface of the hybrid as compared to an alumina powder sourced from the same sol. The proposed approach enables the preparation of chemically homogeneous composite nanopowders with uniform distribution of components.

关键词： Nanoparticles  

摘要： Hematite nanoparticles have been prepared from Moringa oleifera leaf extracts. Phytochemicals are derived from plant extracts which act as a stabilizing and capping agent as well as a surfactant. This green route protocol is attractive owing to its speed, reliability, and ecofriendly and cost-effective qualities. The synthesized iron oxide nanoparticles were subjected to three different calcination temperatures (500, 600, and 700 degrees C). The crystallinity nature and phase purity have been confirmed by powder X-ray diffraction (PXRD). Optical properties have been studied by LTV-visible (UV-vis) and diffuse reflectance spectroscopy (DRS). A very narrow bandgap was observed, and absorbance was observed at the visible region. Photoluminescence spectra have exhibited a multicolor emission band from the near UV to visible region due to defect centers (F centers). EDX (energy dispersive X-ray spectrum) has given information on the stoichiometric ratio of Fe and O. The functional groups which are responsible for nanoparticle formation have been identified by Fourier transformed infrared spectroscopy (FTIR), surface morphology transformation has been illustrated by scanning electron microscopy (SEM) studies, and VSM measurements have exhibited a hysteresis curve that shows the weak and strong ferromagnetic behavior in nature at RT. TEM micrographs have confirmed that particles are in the nanorange, matching the results from the XRD report. The SAED pattern gives information on the polycrystalline nature of hematite nanoparticles. TG-DSC characterization revealed phase transition, decomposition, and weight loss information. Frequency-dependent electrical properties were studied. Here, we report what the present studies have revealed: that hematite nanopowder prepared from the green route is environmentally friendly, takes a short time to prepare, is an economical and promising candidate material for electromagnetic devices and ferromagnet manufacturing, and is a photocata

关键词： Ocimum album seed   Polysaccharide   Purification   H-1 and( )(13)C NMR  

摘要： In this study, a novel polysaccharide fraction from Ocimum album seed was extracted and then purified by Cellulose DEAE-52 and Sephadex G-200 anion exchange chromatography. The structural, physicochemical and antioxidant properties of the main polysaccharide fraction (OAP-1A) were evaluated. The purified polysaccharide contained 94.3% carbohydrate, 3.56% moisture and 2.14% ash and result of gel permeation chromatography (GPC) showed average molecular weight of 593 kDa. The results of high-performance liquid chromatography (HPLC) showed that OAP-1A was a neutral hetero-polysaccharide composed of mannose (35.7%), glucose (33.32%), galactose (19.6%) and rhamnose (11.38%). In addition, GC MS data. nuclear magnetic resonance (NMR) spectrum and Fourier transform infrared (FT-IR) analysis revealed that the backbone of OAP-1A consists of -> 3)-beta-D-Manp-(1 ->, -> 3,4)-beta-D-Manp-(1 ->, -> 3,6)-beta-D-Manp-(1 ->, -> 3)-alpha-D-Glcp-(1 ->, -> 6)-beta-D-Galp-(1 ->, -> 4)-alpha-L-Rhap-(1 -> and alpha-D-Glcp-(1 ->. X-ray diffraction (XRD) analysis showed semi-crystalline structure in OAP-1A. Differential scanning colorimeter (DSC) and thermo-gravimetry analysis (TGA) indicated that OAP-1A had relatively high thermal stability. Moreover. OAP-1A showed strong scavenging activity against 2,2-diphenyl-1-piaylhydrazyl (DPPH) radicals. (C) 2021 Published by Elsevier B.V.

关键词： Municipal solid waste   Heating value   Proximate analysis   Ash composition   Fuel potential  

摘要： The recycling of materials found in municipal solid waste (MSW) is preferable to energy recovery;however, parts of the residues are rejected and sent to landfills. Rejects can be processed and used as refuse-derived fuel (RDF);nevertheless, an assessment of the fuel properties is relevant. This work evaluated the fuel potential of rejected MSW by manually sorting recyclable products, dominated by discarded recyclable solid waste (DRSW), aiming at recovery using it as RDF in thermochemical processes. The methodologies employed contemplated the physicochemical and thermophysical characterization of samples from five different fractions (non-chlorinated plastics, paper/cardboard, textiles, Tetra Pak (R) packaging, and wastes in natura) and processed RDF from DRSW. The results showed that these wastes present important energetic potential (lower heating value of 19.86 MJ/kg, 79.70% of volatile matter, and 8.87% of fixed carbon), with a low chlorine content in the bottom ash (11.43%). The samples tested in this work had moisture, ash, and combustible matter percentages within the limits established by the Tanner diagram. Therefore, the use of DRSW as RDF is an alternative to waste treatment, promotes energy recovery, and reinforces the goals of the United Nations 2030 Agenda for Sustainable Development due to the socioenvironmental and economic benefits of using rejected waste.

关键词： 物理化学   热力学第二定律   能源利用效率  

摘要： 以物理化学课程中的热力学第二定律作为研究对象,阐述热力学第二定律中蕴藏的元素,探讨保护生态环境、利用自然资源时充分考虑自然规律,从而提高能源利用效率。

关键词： 新疆大学   王永刚   应用化学研究   博士毕业   博士后研究   硕士毕业   化学工程专业   物理化学  

摘要： 王永刚教授,本科毕业于新疆大学化学工程专业(2001年);硕士毕业于新疆大学应用化学研究所物理化学专业(2004年),导师张校刚教授;博士毕业于复旦大学化学系物理化学专业(2007年),导师夏永姚教授。博士毕业后,获得日本学术振兴会(JSPS)资助,在日本产业技术综合研究所(AIST)开展博士后研究,导师周豪慎教授(*** Zhou),2011年加入复旦大学化学系,2015年晋升为教授。

关键词： 土壤污染   修复   微生物   物理化学  

摘要： 土壤污染具有潜伏性、长期性、不可逆性等特点,农田重金属污染不仅会影响土壤的理化性质,还能抑制农作物生产降低农产品的产量和质量,并通过食物链富集到人体中,从而威胁人体健康。本文首先分析了我国土壤污染现状,然后归纳了土壤污染类型及危害,最后详细阐述了土壤污染修复及其技术展望。

关键词： Highland barley   Thermal treatment   Physicochemical   Microstructure   Bioactive components   Antioxidant  

摘要： Highland barley (HB) was subjected to three thermal treatments (heat fluidization, microwave, and baking) and assessed for physicochemical, ultrastructural and nutritional properties. After thermal treatments, the hardness, bulk density, thousand kernel weight, length/breadth ratio, and color difference decreased significantly, while puffing index increased. Meanwhile, the formation of fissure was observed in the appearance. Microstructure images illustrated that numerous micropores were evenly distributed in the endosperm structure, and aleurone layer cells were deformed by compression. Furthermore, a dramatically disruption of endosperm cell walls and slightly deformation of outer layers were observed by confocal laser scanning microscopy. Moreover, a notably decrease in total phenolics (14.02%-36.91%), total flavonoids (25.28%-44.94%), and bound phenolics (8.99%- 27.53%) was detected, while free phenolics (8.81%-43.40%), beta-glucan extractability (4.71%-43.66%), antioxidant activity (71.87%-349.77%), and reducing power (3.05%-56.13%) increased significantly. Greatest increase in nutritional values was caused by heat fluidization, which possessed the potential for development of ready-to-eat functional foods.

关键词： Chloramphenicol   gamma-Cyclodextrin   N-acetylcysteine   Molecular modeling   Antibiofilm activity   Reactive oxygen species  

摘要： The aim of this study was to improve the solubility, antibiofilm activity and safety profile of chloramphenicol (CP) by the preparation of multicomponent complexes with gamma-cyclodextrin (gamma-CD) and N-acetylcysteine (NAC). The phase solubility and isothermal titration calorimetry (ITC) studies suggested the complex formation and revealed the solubility of CP is enhanced during the complexation. The most important driving forces of the formation of the complexes were determined by molecular modeling techniques and ITC. Complexation evidence was also provided by data from NMR experiments. The solid-state materials were prepared by physical mixture and freeze-drying methods and subjected to physicochemical characterization using scanning electron microscopy, electron probe microanalysis, thermoanalytical methods and powder X-Ray diffraction. The ability of the materials to decrease the cellular activity of Staphylococcus aureus biofilms was studied by XTT assay. Furthermore, reactive oxygen species determination by chemiluminescence was used to assess the effect of complexation on drug toxicity in human leukocytes. The results obtained allowed us to conclude that the formation of multicomponent complexes of CP with gamma-CD and NAC is an effective pharmaceutical strategy that can enhance the physicochemical and biological properties of this antibacterial drug. (C) 2021 Elsevier B.V. All rights reserved.

关键词： 序列结构   集成设计   西安交通大学   物理化学   安保   集成结构   联合开展   解除保险  

摘要： 西安交通大学与陕西应用物理化学研究所联合开展具备低g值惯性延时解保功能的安全与解除保险机构,并将其用于MEMS火工品的集成结构针对硅基电热MEMS安保作动机构解除保险方式单一且不易感知低环境力的技术难点,西安交通大学与陕西应用物理化学研究所将机械环境力解保与电热力解保相结合,提出了低g值惯性延时电热安保装置,并将其与MEMS火工品序列结构集成设计。