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Hydration kinetics of cementitious materials composed of red mud and coal gangue

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International Journal of Minerals,Metallurgy and Materials 2016年第10期23卷 1215-1224页

作者： Na Zhang hong-xu li Xiao-ming liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction University of Science and Technology Beijing

To elucidate the intrinsic reaction mechanism of cementitious materials composed of red mud and coal gangue（RGC）, the hydration kinetics of these cementitious materials at 20°C was investigated on the basis of the Krstulovi？-Dabi？ model. An isothermal calorimeter was used to characterize the hydration heat evolution. The results show that the hydration of RGC is controlled by the processes of nucleation and crystal growth（NG）, interaction at phase boundaries（I）, and diffusion（D） in order, and the pozzolanic reactions of slag and compound-activated red mud-coal gangue are mainly controlled by the I process. Slag accelerates the clinker hydration during NG process, whereas the compound-activated red mud-coal gangue retards the hydration of RGC and the time required for I process increases with increasing dosage of red mud-coal gangue in RGC.

关键词： red mud coal gangue cementitious materials hydration kinetics

Alisol B acetate induces apoptosis of SGC7901 cells via mitochondrial and phosphatidylinositol 3-kinases/Akt signaling pathways

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World Journal of Gastroenterology 2009年第23期15卷 2870-2877页

作者： Yong-hong xu li-Jie Zhao Yan li Department of DigestiveDiseases Shengjing Hospital of China Medical UniversityShenyang 110004 Liaoning Province China

AIM： To examine the effect of alisol B acetate on the growth of human gastric cancer cell line SGC7901 and its possible mechanism of action.METHODS： The cytotoxic effect of alisol B acetate on SGC7901 cells was measured by 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MI-I-） assay. Phase-contrast and electron microscopy were used to observe the morphological changes. Cell cycle and mitochondrial transmembrane potential （A^Pm） were determined by flow cytometry. Western blotting was used to detect the expression of apoptosis-regulated gene Bcl-2, Bax, Apaf-1, caspase-3, caspase-9, Akt, P-Akt and phosphatidylinositol 3-kinases （PI3K）.RESULTS： Alisol B acetate inhibited the proliferation of SGC7901 cell line in a time- and dose-dependent manner. PI staining showed that alisol B acetate can change the cell cycle distribution of SGC7901, increase the proportion of cells in G0-G1 phase and decrease the proportion of S phase cells and G2-M phase cells. Alisol B acetate at a concentration of 30 pmol/L induced apoptosis after 24, 48 and 72 h incubation, with occurrence rates of apoptotic cells of 4.36%, 14.42% and 21.16%, respectively. Phase-contrast and electron microscopy revealed that the nuclear fragmentation and chromosomal condensed, cells shrank and attachment loss appeared in the SGC7901 treated with alisol B acetate. Apoptosis of SGC7901 cells was associated with cell cycle arrest, caspase-3 and caspase-9 activation, loss of mitochondrial membrane potential and up-regulation of the ratio of Bax/Bcl-2 and inhibition of the PI3K/Akt.CONCLUSION： Alisol B acetate exhibits an antiproliferative effect in SGC7901 cells by inducing apoptosis. Apoptosis of SGC7901 cells involves mitochondria-caspase and PI3K/Akt dependent pathways.

关键词： Alisol B acetate Apoptosis Mitochondria Phosphatidylinositol 3-kinases/Akt SGC7901 cells

Recovery of scandium from bauxite residue——red mud:a review

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Rare Metals 2016年第12期35卷 887-900页

作者： Na Zhang hong-xu li Xiao-Ming liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction University of Science and Technology Beijing

Red mud is a slimy caustic residue generated from alumina production. Taking into account the rela- tively considerable content and availability of scandium, red mud can be viewed as an important and promising scandium resource rather than a solid waste. This paper is primarily to review the investigations of scandium recov- ery from red mud based on the most widely used hydrometallurgical processes including acid leaching, sol- vent extraction and ion exchange adsorption. It is thought that recovery of scandium from red mud should be con- sidered as a direct objective rather than a by-product in the development of overall flowsheet. In order to achieve environmentally-friendly processes with high scandium recovery and low cost, more attention is required to be paid to optimizing the selective leaching of scandium to decrease mineral acid consumption and alleviate pollution, and developing new solvent extraction systems and novel ion exchange adsorption materials with high selectivity and recognition for scandium.

关键词： Red mud Scandium Acid leaching Solvent extraction Ion exchange Selectivity

Molecular Biological and Biochemical Studies Reveal New Pathways Important for Cotton Fiber Development

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Journal of Integrative Plant Biology 2007年第1期49卷 69-74页

作者： Yu xu hong-Bin li Yu-Xian Zhu National Laboratory of Protein Engineering and Plant Genetic Engineering Peking University Beijing 100871 China

As one of the longest single-celled seed trichomes, fibers provide an excellent model for studying fundamental biological processes such as cell differentiation, cell expansion, and cell wall biosynthesis. In this review, we summarize recent progress in cotton functional genomic studies that characterize the dynamic changes in the transcriptomes of fiber cells. Extensive expression profilings of cotton fiber transcriptomes have provided comprehensive information, as quite a number of transcription factors and enzyme-coding genes have been shown to express preferentially during the fiber elongation period. Biosynthesis of the plant hormone ethylene is found significantly upregulated during the fiber growth period as revealed by both microarray analysis and by biochemical and physiological studies. It is suggested that genetic engineering of the ethylene pathway may improve the quality and the productivity of cotton lint. Many metabolic pathways, such as biosynthesis of cellulose and matrix polysaccharides are preferentially expressed in actively growing fiber cells. Five gene families, including proline-rich proteins （PRP）, arabinogalactan proteins （AGP）, expansins, tubulins and lipid transfer proteins （LTP） are activated during early fiber development, indicating that they may also be needed for cell elongation. In conclusion, we identify a few areas of future research for cotton functional genomic studies.

关键词： cotton fiber functional genomics plant hormone transcriptome transcription factors

Electron probe microanalysis for revealing occurrence mode of scandium in Bayer red mud

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Rare Metals 2017年第4期36卷 295-303页

作者： Na Zhang hong-xu li Hui-Jing Cheng Xiao-Ming liu School of Metallurgical and Ecological Engineering Universityof Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory of Rare and Precious Metals GreenRecycling and Extraction University of Science and TechnologyBeijing Beijing 100083 China State Key Laboratory of Advanced Metallurgy University ofScience and Technology Beijing Beijing 100083 China

Red mud is a bauxite residue generated during the process of alumina production. In this research, the occur- rence mode of scandium in the Bayer red mud was investi- gated mainly by electron probe microanalysis （EPMA）. The Bayer red mud used in this work is composed of 21.47 wt% hematite, 12.13 wt% goethite, 8.86 wt% gibbsite, 5.02 wt% perovskite, 9.70 wt% quartz, 3.23 wt% anhydrite, 29.92 wt% Na_2Al_2Si_5O_14 and 9.67 wt% Al_3Fe_5O_12. Besides, the scandium content in the Bayer red mud is 84.32 × 10-6, indicating that this Bayer red mud is an important scandium resource deserving exploitation. The EPMA results show that the scandium within the Bayer red mud is mainly occurring in the iron minerals of hematite and goethite with the isomorphism form, but its distribution is not homogeneous in these iron minerals with the Sc_2O_3 content between 330 × 10-6 and 2040 × 10-6. This study provides a theoretical base for the further experimental work on the scandium extraction from this Bayer red mud.

关键词： Scandium Occurrence mode Bayer red mud Electron probe microanalysis

Alloy/layer double hydroxide interphasic synergy via nano-heterointerfacing for highly reversible CO_(2)redox reaction in li-CO_(2)batteries

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Nano Research 2024年第6期17卷 5206-5215页

作者： Tianzhen Jian Wenqing Ma Jiagang Hou Jianping Ma Xianhong li Haiyang Gao Caixia xu hong liu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongSchool of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China Kyiv College at Qilu University of Technology Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China Shandong Sacred Sun Power Sources Co. Ltd.Qufu 273100China

li-CO_(2)batteries are among the most intriguing techniques for balancing the carbon cycle,but are challenged by the annoyed thermodynamic barrier of the li_(2)CO_(3)decomposition ***,we demonstrate the electrocatalytic performances of two-dimensional(2D)CoAl-layer double hydroxide(LDH)nanosheets can be significantly improved by trans-dimensional crosslinking with three-dimensional(3D)multilevel nanoporous(MP)-RuCoAl alloy(MP-RuCoAl alloy⊥CoAl-LDH).The MP-RuCoAl alloy⊥CoAl-LDH with multiscale pore channels and abundant nano-heterointerface is directly prepared by controllable etching Al from a Ru-Co-Al master alloy along with simultaneous partial oxidization of Al and Co *** MP-RuCoAl is composed of various intermetallic compounds and Ru with abundant grain boundaries,and forms numerous heterointerface with 2D CoAl-LDH *** multiscale porous metallic network benefits mass and electron transportation as well as discharge product storage and enables a rich multiphase reaction *** situ differential electrochemical mass spectrometry shows that the mass-to-charge ratio in the charging process is~0.733 which is consistent with the theoretical value of 3/4,stating that the reversible co-decomposition of li_(2)CO_(3)and C can be achieved with the MP-RuCoAl alloy⊥*** Ketjen black(KB)/MP-RuCoAl⊥CoAl-LDH battery demonstrates a high cyclability for over 2270 h(227 cycles)with a lower voltage gap stabilized at~1.3 V at 200 mA·g^(−1).Our findings here provide useful guidelines for developing high efficiency transition metal based electrocatalysts by coupling with conductive porous substrate for impelling the development of practical li-CO_(2)battery systems.

关键词： heterojunction interface nanoporous li-CO_(2)battery dealloying

Boosting reversible charging of li-ion batteries at low temperatures by a synergy of propylene carbonate-based electrolyte and defective graphite

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Nano Research 2024年第3期17卷 1491-1499页

作者： Yingqiang Wu Jiao Zhang Jinli liu li Sheng Bo Zhang limin Wang Siqi Shi li Wang hong xu Xiangming He Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences(CAS)Changchun 130022China China National Quality Supervision and Inspection Center for Industrial Explosive Materials Nanjing University of Science and TechnologyNanjing 210094China School of Materials Science and Engineering Materials Genome InstituteShanghai UniversityShanghai 200444China

Propylene carbonate(PC)-based electrolytes have exhibited significant advantages in boosting the low-temperature discharging of graphite-based li-ion ***,it is still unclear whether they can improve the charging property and suppress lithium *** this topic is challenging due to the problem of electrochemical *** overcome this issue,we introduced graphite with phase *** results show that the pouch-type full batteries using PC-based electrolyte exhibit steady performance over 500 cycles and can be reversibly charged over 30 times at-20℃ with an average Coulombic efficiency of 99.95%,while the corresponding value for the conventional ethylene carbonate(EC)-based electrolyte sample is only 31.20%.This indicates that the use of PC-based electrolyte significantly suppresses lithium plating during low-temperature *** further demonstrate that the improved performance is mainly attributed to the unique solvation structure,where PF-6more anions participate in solvation,leading to the formation of a stable F-rich solid state electrolyte interface on the graphite surface and a lower reduction tendency of li+*** work inspires new ideas for the design of PC-based electrolytes for low-temperature charging and fast-charging batteries.

关键词： lithium-ion batteries graphite propylene carbonate low-temperature charging

Synthesis,Characterization and Antibacterial Activity of New 5-Aryl Pyrazole Oxime Ester Derivatives

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Chemical Research in Chinese Universities 2008年第4期24卷 454-458页

作者： liU Xin-hua ZHI li-ping SONG Bao-an xu hong-li Key Laboratory of Anhui Educational Department Faculty of Mathematics ＆ Physics Anhui University of Technology Ma ＇anshan 243002 P R. China Key Laboratory of Green Pesticide and Agriculture Bioengineering Ministry of Education Guizhou University Guiyang 550025 P. R. China

Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations（MIC） of 1.562--3.125 ug/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase（IC50=1.9--2.5 ug/mL）. On the basis of the biological activities, structure-activity relationship was discussed.

关键词： 5-Aryl pyrazole Oxime ester Antibacterial activity

High quality Sb-doped SnO2 electrodes with high oxygen evolution potential prepared by in situ hydrothermal synthesis method

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Chinese Chemical Letters 2007年第8期18卷 997-1000页

作者： Ai Sheng Huang Guo Hua Zhao hong xu li Department of Chemistry Tongji University Shanghai 200092 China

High quality Sb-doped SnO2 electrode, with high oxygen evolution potential of 3.0 V, was successfully synthesized on the Ti substrates by in situ hydrothermal synthesis method.

关键词： Metallic oxide electrode Hydrothermal synthesis Oxygen evolution reaction