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Electronic Structure and Magnetic Properties of Cr-Doped AlN

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Communications in Theoretical Physics 2007年第4X期48卷 749-753页

作者： CHEN hong ZHANG jun-feng YUAN hong-Kuan School of Physical Science and Technology Southwest University Chongqing 400715 China

To understand the electronic and magnetic properties, we have studied Cr-doped zinc-blende AlN system in detail by applying a first-principle plane wave pseudopotential method based on the density functional theory within the local spin density approximation. The analyses of the band structures, density of states, exchange interactions, and magnetic moments show that Al1-xCrxN alloys may exhibit a half-metallic ferromagnetism character, that Cr in the diluted doping limit forms near-midgap deep levels, and that the total magnetization of the cell is 3μB per Cr atom, which does not change with Cr concentration. Moreover, we have succeeded in predicting that Al1-xCrzN alloys in x = 0.0625 has a very high Curie temperature, and lind that ferromagnetic exchange interaction between magnetic dopants is short-ranged.

关键词： density functional theory electronic structure magnetism Curie temperature

Synthesis and Crystal Structure of Dehydroandrographolide Dipolycyclophosphate

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1198-1202页

作者： XU Hai-Wei WANG jun-feng LIU hong-Min ZHANG Jian-Ye New Drug Research ＆ Development Center Zhengzhou University Zhengzhou 450052 China

The title compound was synthesized and characterized by IR, NMR, HRSI-MS and MS, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic system （C40H52O11P2, Mr= 770.76）, space group P21212, with a = 22.562（5）, b = 29.224（6）, c = 7.1953（14） A, V = 4744.2（16） A^3, Z = 4, Dc = 1.079 g/cm^3, F（000） = 1640 and μ = 0.141 mm^-1. The final R = 0.0758 and wR = 0.1778 for 2794 observed reflections with I 〉 20（I）. Intermolecular hydrogen bonds are found between the O atom of carbonyl group and H atoms of olefinic carbon. The absolute configuration of this molecule was confirmed by comparison with that of the original material.

关键词： crystal structure andrographolide cyciophosphate synthesis

A robust viscoelastic surfactant tolerating 20% HCl up to 150℃ for oil well stimulation

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Petroleum Science 2024年第3期21卷 1865-1874页

作者： Ji Wang Ning Qi hong-Yao Yin Yu-jun feng Polymer Research Institute State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065SichuanPR.China Tianfu Yongxing Laboratory New Theory and Technology of CO_(2) Capture Research CenterChengdu610065SichuanPR China School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China

Viscoelastic surfactants(VES)are often used as viscous diverters in acidizing stimulation to prolong the acid consumption time and maximize zonal coverage of the acid for improving well ***,the ceiling temperature of commercial VES cannot exceed 120℃in practical use because of the poor thermal stability and fragile molecular structure,hindering their implementation in hightemperature oil reservoirs,i.e.,≥150℃.Here we synthesized a novel C22-tailed diamine,N-erucaminopropyl-N,N-dimethylamine(EDPA),and examined comparatively its rheological behavior,assemblies morphology and molecular stability in 20 wt%HCl with a commercial VES,erucyl dimethyl amidopropyl betaine(EDAB).The feasibility of EDPA for acidizing stimulation was assessed by acid etching of carbonate rock with its HCl solution at 150℃.Rheological results showed that the 2.5 wt%EDPA—20 wt%HCl solution maintains stable viscosity of 90 m Pa s at 150℃for 60 min,while that of 2.0 wt%EDAB HCl solution is just 1 m Pa s under identical conditions.1H NMR spectra and cryo-TEM observations revealed that the chemical structure and self-assembled architectures of EDPA remained intact in such context,but the EDAB suffered from degradation due to the hydrolysis of the amide group,accounting for the poor heat-resistance and *** reaction rate of 2.5 wt%EDPA HCl solution with carbonate rock was one order of magnitude lower than that of 20 wt%HCl solution at 150℃,underpinning the potential of EDPA to be used in the high-temperature reservoirs *** work improved the thermal tolerance of VES in highly concentrated HCl solution,paving a feasible way for the acidization of high-temperature reservoir environments(~150℃).

关键词： Viscoelastic surfactants Thermal stability Self-diverting acid Wormlike micelles Acidizing stimulation

Inositol and Phosphatidylinositol Mediated Glucose Derepression, Gene Expression and Invertase Secretion in Yeasts

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Acta Biochimica et Biophysica Sinica 2004年第7期36卷 443-449页

作者： Zhen-Ming CHI*, jun-feng LI, Xiang-hong WANG, and Shu-Min YAOUNESCO Chinese Center of Marine Biotechnology, Ocean University of China, Qingdao 266003, China UNESCO Chinese Center of Marine Biotechnology Ocean University of ChinaQingdao 266003 China

Glucose repression occurs in many yeast species and some filamentous fungi, and it represses the expression and secretion of many intracellular and extracellular proteins. In recent years, it has been found that many biochemical reactions in yeast cells are mediated by phosphatidylinositol (PI)-type signaling pathway. However, little is known about the relationships between PI-type signaling and glucose repression, gene expression and invertase secretion in yeasts. Many evidences in our previous studies showed that glucose repression, invertase secretion, gene expression and cell growth were mediated by inositol and PI in Saccharomyces and Schizosaccharomyces. The elucidation of the new regulatory mechanisms of protein secretion, gene expression and glucose repression would be an entirely new aspect of inositol and PI-type signaling regulation in yeasts.

关键词： glucose repression PI-type signaling pathway invertase secretion gene expression

Thoracic spinal cord injury and paraplegia caused by intradural cement leakage after percutaneous kyphoplasty: A case report

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World Journal of Clinical Cases 2024年第10期12卷 1837-1843页

作者： Zi Mao Zhi-hong Xiong jun-feng Li Department of Pain Management The Affiliated Hospital of Yunnan UniversityKunming 650000Yunnan ProvinceChina Department of Medical Administration The Affiliated Hospital of Yunnan UniversityKunming 650000Yunnan ProvinceChina

BACKGROUND Percutaneous kyphoplasty(PKP)is a pivotal intervention for osteoporotic fractures,pathological vertebral compression fractures,and vertebral bone *** its efficacy,the procedure presents challenges,notably complications arising from intradural cement *** and accurate diagnosis,coupled with emergent intervention is imperative to improve patient *** case report illuminates the intricacies and potential complications associated with PKP,emphasizing the critical need for vigilant monitoring,prompt diagnosis,and immediate intervention to mitigate adverse *** SUMMARY A 58-year-old male patient,experiencing a T7 osteoporosis-related pathological compression fracture,underwent PKP at a local *** weeks postprocedure,the patient developed paraplegic and dysuric symptoms,necessitating emergency decompression *** improvement was achieved,marked by the restoration of muscle strength,sensation,and *** PKP Intradural cement leakage following PKP is unusual and potentially *** imaging examinations,urgent evaluation,and the decompression surgery are essential,which help alleviate symptoms associated with spinal damage,markedly improving the overall prognosis.

关键词： Percutaneous kyphoplasty Intradural cement leakage Complication Decompression surgery Case report

Atomization characteristics of pyrolysis oil derived from waste tires

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Waste Disposal and Sustainable Energy 2024年第1期6卷 39-52页

作者： hong feng Zhitong Yin Qin hong Yiming Hu Lintao Liu jun Wang Qunxing Huang Yonggang Zhou ZJMI Environmental Energy Co. LtdHangzhou310003China Tongxiang Taiaisi Environmental Protection Energy Co. Ltd.Jiaxing314500China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou310027China Key Laboratory of Clean Energy and Carbon Neutrality of Zhejiang Province Jiaxing Research InstituteZhejiang UniversityJiaxing314031China

The atomization characteristics play a key role in the highly efficient combustion of pyrolysis oil derived from waste *** this study,the fuel properties of tire pyrolysis oil(TPO)were initially studied,and then a high-speed camera and a phase Doppler particle analyzer were employed to characterize the atomization feature of *** influence of pressure and nozzle orifice diameter on atomization characteristics such as spray angle,droplet velocity,and droplet size distribution was *** results showed that TPO had a high calorific value of about 43.6 MJ/kg and a low viscosity of 3.84×10^(–6)m^(2)/s at 40℃,which made it have the potential to be used as an alternative *** pressure expanded the spray angle and extended the spray in both the axial and radial *** increasing pressure,spray angle and droplet velocity raised,and the increase in crushing effect of air reduced the Sauter mean diameter(SMD)of the *** obtain proper atomization quality for combustion,the pressure is expected to be higher than 1.25 *** increasing nozzle orifice diameter,droplet velocity increased,and the SMD of the droplets increased as well due to weakened crushing effect of the ***,the pressure must be increased to maintain the atomization quality when using a nozzle with a larger *** to the lower viscosity,the velocity and particle size distribution of TPO droplets after atomization were smaller than those of diesel *** extremely small carbon black contained in TPO also contributed to the breaking of droplets and played a certain role in the size reduction of the oil droplets,but it may cause the risk of nozzle *** summary,TPO showed great atomization characteristics for alternative fuel applications.

关键词： Pyrolysis oil Atomization characteristics Spray angle Droplet velocity Droplet size distribution

Rational design of metal selenides nanomaterials for alkali metal ion(Li^(+)/Na^(+)/K^(+))batteries:current status and perspectives

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Rare Metals 2024年第5期43卷 1906-1931页

作者： Rui Sun feng Xu Cai-hong Wang Sheng-jun Lu Yu-Fei Zhang Hao-Sen Fan College of Materials Science and Metallurgy Engineering Guizhou UniversityGuiyang550025China School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou510006China

Recently,metal selenides have obtained widespread attention as electrode materials for alkali(Li^(+)/Na^(+)/K^(+))batteries due to their promising theoretical capacity and ***,metal selenides,similar to metal oxides and sulfides,also suffer from severe volume explosion during repeated charge/discharge processes,which results in the structure collapse and the following pulverization of electrode ***,it leads to poor cycle stability and influencing their further *** order to solve these issues,some special strategies,including elemental doping,coupling with carbon materials,synthesis of the bimetal selenides with heterostructure,etc.,have been gradually applied to design novel electrode materials with outstanding electrochemical ***,the recent research progress on metal selenides as anodes for alkali ion batteries is summarized,including the regulation of crystal structure,synthesis strategies,modification methods,and electrochemical mechanisms and ***,the challenges of metal selenides and the perspective for future electrode material design are *** is hoped to pave a way for the development of metal selenide electrode materials for the potential applications for alkali metal ion(Li^(+)/Na^(+)/K^(+))batteries.

关键词： Rational design Metal selenides Nanostructure Li^(+) batteries Na^(+) batteries K^(+) batteries

Low Selenium and Low Protein Exacerbate Myocardial Damage in Keshan Disease by Affecting the PINK1/Parkin-mediated Mitochondrial Autophagy Pathway

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Current Medical Science 2024年第1期44卷 93-101页

作者： Li-wei ZHANG hong-qi feng Song-bo FU Dian-jun SUN Center for Endemic Disease Control Chinese Center for Disease Control and PreventionHarbin Medical UniversityNHC Key Laboratory of Etiology and Epidemiology(Harbin Medical University)Key Lab of Etiology and EpidemiologyEducation Bureau of Heilongjiang ProvinceHarbin 150086China

Objective Keshan disease(KD)is a myocardial mitochondrial disease closely related to insufficient selenium(Se)and protein *** induced putative kinase 1(PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the *** study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial *** A low Se and low protein animal model was *** hundred Wistar rats were randomly divided into 5 groups(control group,low Se group,low protein group,low Se+low protein group,and corn from KD area group).The JC-1 method was used to detect the mitochondrial membrane potential(MMP).ELISA was used to detect serum creatine kinase MB(CK-MB),cardiac troponin I(cTnI),and mitochondrial-glutamicoxalacetic transaminase(M-GOT)***-PCR and Western blot analysis were used to detect the expression of PINK1,Parkin,sequestome 1(P62),and microtubule-associated proteins1A/1B light chain 3B(MAP1LC3B).Results The MMP was significantly decreased and the activity of CK-MB,cTnI,and M-GOT significantly increased in each experimental group(low Se group,low protein group,low Se+low protein group and corn from KD area group)compared with the control group(P<0.05 for all).The mRNA and protein expression levels of PINK1,Parkin and MAP1LC3B were profoundly increased,and those of P62 markedly decreased in the experimental groups compared with the control group(P<0.05 for all).Conclusion Low Se and low protein levels exacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.

关键词： Keshan disease low selenium and low protein myocardial mitochondrial injury PTEN induced putative kinase 1(PINK1)/Parkin mitochondrial autophagy

Aging Behavior of As-Extruded Ti Particles Reinforced VW94 Composites

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 401-406页

作者： Dongmei Pu Xianhua Chen Jingfeng Wang jun Tan Jianbo Li hong Yang Bo feng Kaihong Zheng Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400045China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China

The ageing behavior of as-extruded Ti_(P)/VW94 composites was *** peak hardness of the composites increases compared to the matrix alloy and the 5%Ti_(P)/VW94 composite presents the highest peak hardness of 148.7 HV after aging for about 50 ***,the hardness increments first decrease and then slightly increase with increasing Ti particle content due to the introduction of high-density dislocations by Ti particles.

关键词： Magnesium matrix composites Ti particles Ageing behavior Hardness