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Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

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International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 311-316页

作者： Run-lan Yu Jing Liu jian-xi Tan Wei-min Zeng Li-juan shi guo-hua gu Wen-qing Qin guan-zhou Qiu School of Minerals Processing and Bioengineering Central South University Key Laboratory of Biometallurgy Ministry of Education Hunan Entry-Exit Inspection and Quarantine Bureau

The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular poly-saccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleach-ing. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

关键词： chalcopyrite bioleaching polysaccharides acidity Acidithiobacillusferrooxidans

Metal–Organic Framework‑Based Photodetectors

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Nano-Micro Letters 2024年第11期16卷 675-703页

作者： Jin‑Biao Zhang Yi‑Bo Tian Zhi‑Gang gu jian Zhang State Key Laboratory of Structural Chemistry Structure of MatterFujian Institute of ResearchChinese Academy of SciencesFuzhouFujian 350002People’s Republic of China College of Chemistry and Materials Science Fujian Nornal UniversityFuzhou 350007FujianPeople’s Republic of China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianPeople’s Republic of China University of Chinese Academy of Science Beijing 100049People’s Republic of China

The unique and interesting physical and chemical properties of metal–organic framework(MOF)materials have recently attracted extensive attention in a new generation of photoelectric *** this review,we summarized and discussed the research progress on MOF-based *** methods of preparing MOF-based photodetectors and various types of MOF single crystals and thin film as well as MOF composites are introduced in ***,the photodetectors applications for X-ray,ultraviolet and infrared light,biological detectors,and circularly polarized light photodetectors are ***,summaries and challenges are provided for this important research field.

关键词： Metal-organic frameworks Semiconductor Photodetectors

Numerical simulation study on the mold strength of magnetic mold casting based on a coupled electromagnetic-structural method

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China Foundry 2024年第5期21卷 577-587页

作者： Wei-li Peng jian-hua Zhao Cheng gu Ya-jun Wang College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast *** this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled electromagnetic-structural method through numerical *** study investigated key factors including equivalent stress,the distribution of tensile and compressive stresses,and the area ratio of tensile *** compared molds made entirely of magnetic materials with those made partially of magnetic *** results indicate that as current increases from 4 A to 8 A,both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress,tensile-compressive stress,and the area ratio of tensile stress,peaking at 6 A before *** material replacement,the area ratio of tensile stress at 6 A decreases to 19.84%,representing a reduction of 29.72%.Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic *** study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds.

关键词： magnetic mold casting coupled electromagnetic-structural method numerical simulation stress analysis

Characterization and immunogenicity of bone marrow-derived mesenchymal stem cells under osteoporotic conditions

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Science China(Life Sciences) 2020年第3期63卷 429-442页

作者： Yingkang Huang Yin Yin Yanzheng gu Qiaoli gu Huilin Yang Zhengyu Zhou Qin shi Orthopedic Department the First Affiliated Hospital of Soochow UniversityMedical College of Soochow UniversityOrthopedic Institute of Soochow UniversitySuzhou 215006China Laboratory Animal Center Medical College of Soochow UniversitySoochow UniversitySuzhou 215123China Clinical Immunology Institute of jiangsu Province the First Affiliated Hospital of Soochow UniversitySuzhou 215006China Key Laboratory of Stem Cells and Biomedical Materials of jiangsu Province and Chinese Ministry of Science and Technology Suzhou 215123China

Mesenchymal stem cells (MSCs) are characterized by their multilineage potential and low ***,the properties of MSCs under pathological conditions are *** current study investigated the differentiation potential and immunological characteristics of bone marrow-derived MSCs from ovariectomized-osteoporotic rats (OP-BMSCs).Although the expression of cell morphology-and sternness-related surface markers was similar between OP-BMSCs and BMSCs from healthy rats (H-BMSCs),the proliferation rate was significantly decreased compared with that of *** multilineage potential,osteogenesis and chondrogenesis abilities of OP-BMSCs decreased,but the adipogenesis ability was significantly enhanced compared with that of *** expected,decreased osteogenesis following osteogenic induction resulted in reduced expression of p-catenin,osteocalcin,and runt-related transcription factor 2 in ***,the expression of the co-stimulatory proteins CD40 and CD80 was significantly higher,whereas the expression of the negative costimulatory molecule programmed cell death ligand 1 was significantly lower in the OP-BMSCs than that in ***,H-BMSCs inhibited the proliferation and secretion of inflammatory cytokines from anti-CD3 antibody-activated T cells,whereas OP-BMSCs did *** results indicate that decreased osteogenesis and increased immunogenicity of OPBMSCs contribute to bone loss in osteoporosis.

关键词： mesenchymal stem cells osteogenesis chondrogenesis adipogenesis immunogenicity osteoporosis

Intercalation-pseudocapacitance hybrid anode for high rate and energy lithium-ion capacitors

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Journal of Energy Chemistry 2021年第4期30卷 459-467页

作者： Chang Liu Ali Khosrozadeh Qing-Qing Ren Ling-Hui Yan Kokswee Goh shi-Han Li jian Liu Lei Zhao Da-Ming gu Zhen-Bo Wang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage State Key Lab of Urban Water Resource and EnvironmentSchool of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001HeilongjiangChina School of Engineering Faculty of Applied ScienceUniversity of British ColumbiaKelowna V1V 1V7BCCanada

Existing rechargeable batteries not only fail to meet the demand for high power applications but also cause heavy metal ***-ion capacitors(LICs),which can achieve higher charging speeds and energy densities than supercapacitors,have attracted extensive ***,sluggish Li-ion diffusion of the battery-type anode results in limited rate performance of ***,highperformance LICs using both battery and capacitor type Mn_(2)V_(2)O_(7)-graphene(MVO-G)anodes and hempstem-derivated activated carbon(HSAC)cathodes with a large surface area are first *** addition to high pseudocapacitance,the MVO-G possesses the advantage of fast Li^(+)storage performance making it a suitable choice for advanced LIC *** is employed to enhance overall conductivity and cycling stability leading to enhanced energy *** MVO-G//HSAC LICs exhibit a high energy density of 148.1 Wh kg^(-1) at a power density of 150 W kg^(-1) and 25 Wh kg^(-1) even at15 k W kg^(-1).More importantly,the MVO-G//HSAC LICs also show excellent cycling stability of 90%after15,000 cycles,which is expected for high performance energy storage systems.

关键词： Manganese vanadate Graphene Pseudocapacity Hempstem-based activated carbons Lithium ion capacitor

The synthesis of dialdehydes from dicarboxylic acids via imidazolines

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Chinese Science Bulletin 1997年第2期42卷 130-132页

作者： shi, Z gu, H Xu, LL Department of Chemistry Northwest University Xi’an China

DIALDEHYDES are important chemical industrial materials, which are widely used in textile,medicine, dye, binder, coating and so on. The traditional method for preparing dialdehydes is the catalytic oxidation of glycol. We have reported the reduction ring-opening reaction of inndazoline by NaBH4.In this note, the reduction of imidazoline by sodium and ethanol is studied. A new synthetic method for the preparation of dialdehydes from dicarboxylic acids

关键词： dicarboxylic acid imidazoline dialdehyde new synthetic method.

Anisotropic characteristics of granular materials under simple shear

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Journal of Central South University 2013年第8期20卷 2275-2284页

作者： QIAN jian-gu YOU Zi-pei HUANG Mao-song Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education (Tongji University) Shanghai 200092 China Department of Geotechnical Engineering Tongji University Shanghai 200092 China

The discrete element method was used to investigate the microscopic characteristics of granular materials under simple shear loading conditions. A series of simple tests on photo-elastic materials were used as a benchmark. With respect to the original experimental observations, average micro-variables such as the shear stress, shear strain and the volumetric dilatancy were extracted to illustrate the performance of the DEM simulation. The change of anisotropic density distributions of contact normals and contact forces was demonstrated during the course of simple shear. On the basis of microscopic characteristics, an analytical approach was further used to explore the macroscopic behaviors involving anisotropic shear strength and anisotropic stress-dilatancy. This results show that under simple shear loading, anisotropic shear strength arises primarily due to the difference between principal directions of the stress and the fabric. In addition, non-coaxiality, referring to the difference between principal directions of the strain rate and the stress, generates less stress-dilatancy. In particular, the anisotropic hardening and anisotropic stress-dilatancy will reduce to the isotropic hardening and the classical Taylor’s stress-dilatancy under proportional loading.

关键词： simple shear discrete element method anisotropy non-coaxiality

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高铁开通对长三角地区旅游业发展的影响研究

西南大学学报（自然科学版） 2025年第2期47卷 106-121页

作者：时朋飞古俊龙黄荣娟张鸿浩李星明西南大学经济管理学院重庆400715 河池学院商学院广西宜州546300 华中师范大学城市与环境科学学院武汉430079

在系统阐述高铁开通与旅游业发展内在关联的基础之上,基于2010-2019年长三角地区41个城市的面板数据,运用倾向得分匹配法与多期渐进倍差法评估高铁开通对长三角地区城市旅游业发展数量和质量的影响。研究结果表明:①基于整体视角,高铁... 详细信息

在系统阐述高铁开通与旅游业发展内在关联的基础之上,基于2010-2019年长三角地区41个城市的面板数据,运用倾向得分匹配法与多期渐进倍差法评估高铁开通对长三角地区城市旅游业发展数量和质量的影响。研究结果表明:①基于整体视角,高铁开通促进了长三角地区城市旅游业发展数量与质量的双提升,对发展质量的影响程度大于对发展数量的影响程度,同时高铁开通对该地区城市旅游业存在既“旺财”又“旺丁”的效果;②基于异质性视角,高铁开通对新一线及以上城市旅游业发展质量有微弱正向作用,但无法助推其发展数量的提升,对二线城市旅游业发展数量影响强而对发展质量影响较弱,对三线、四线及以下城市旅游业发展质量的提升影响较大而对发展数量影响微弱,这类城市沦为高铁旅游的“过道”;③基于驱动力视角,技术进步成为该地区旅游业全要素生产率提升的核心动力,同时高铁开通对除四线及以下城市的发展层次城市技术进步的驱动作用强于对技术效率的驱动作用。据此,在加快旅游强国建设背景下,应将高铁建设纳入推进区域旅游业高质量发展的有效手段和政策工具,通过高铁网络完善产生的杠杆效应进一步促进区域旅游一体化建设、旅游技术创新与扩散、技术效率改进与提升。

关键词：旅游业发展高铁开通倾向得分匹配法多期渐进倍差法长三角地区

Pilot power based rate control in CDMA 2000 1x EV-DO Rev-A

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 118-122页

作者： LIU Xiao-feng gu jian YANG Hong-wen Wireless communication Center Beijing University of Posts andTelecommunications Beijing 100876 China

This article proposes a new algorithm to improve the rate control efficiency of enhanced reverse link medium access control （RLMAC） in the code division multiple access （CDMA） 1x EV-DO release A（Rev. A） system. The new algorithm brings reverse access terminal （AT） pilot power to the RLMAC rate control procedure and makes it easier for a low pilot power user to increase its data rate when the system is slightly loaded and harder to decrease its date rate when the system is heavily loaded. Numerical results of system level simulations show that the new algorithm can bring higher system throughput, lower AT transmission power, and lower system load.

关键词： RLMAC CDMA 1x EV-DO pilot power rate control