期刊文献+
共找到679篇文章
< 1 2 34 >
每页显示 20 50 100
Direction-dependent functions of physical properties for crystals and polycrystals
1
作者 Mojia Huang Mengcheng Chen Tenglong Zheng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第5期639-649,共11页
Some physical properties of crystals differ in direction n because crystal lattices are often anisotropic. A polycrystal is an aggregate of numerous tiny crystallites. Unless the polycrystal is an isotropic aggregate ... Some physical properties of crystals differ in direction n because crystal lattices are often anisotropic. A polycrystal is an aggregate of numerous tiny crystallites. Unless the polycrystal is an isotropic aggregate of crystallites, the physical properties of the polycrystal vary with n. The direction-dependent functions (DDF) for crystals and polycrystals are introduced to describe the variations of the physical properties in direction n. Until now there are few papers dealing systematically with relations between the DDF and the crystalline orientation distribution. Herein we give general expressions of the DDF for crystals and polycrystals. We discuss the applications of the DDF in describing the physical properties of crystals and polycrystals. 展开更多
关键词 Direction-dependent function Orientation distribution function physical properties of crystals and polycrystals
下载PDF
Mathematical Wave Functions and 3D Finite Element Modelling of the Electron and Positron
2
作者 Declan Traill 《Journal of Applied Mathematics and Physics》 2024年第4期1134-1162,共29页
The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric an... The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles. 展开更多
关键词 ELECTRON POSITRON Wave Function Solution Electromagnetic Spin Mass Charge Proof Fundamental Particle properties Quantum Mechanics Classical Physics Computer 3D Model Schrödinger Equation RMS KLEIN GORDON Electric Magnetic Lorentz Invariant Hertzian Vector Point Potential Field Density Phase Flow Attraction REPULSION Shell Theorem Ehrenfest VIRIAL Normalization Harmonic Oscillator
下载PDF
Analysis of Winter Physical Training and Functional Reserve in College Physical Education Teaching
3
作者 Dawei Guo 《Journal of Contemporary Educational Research》 2023年第7期26-29,共4页
Physical training and functional reserve in winter physical education teaching can optimize the energy consumption of the body,regulate cardiopulmonary function,and stabilize emotions.It is essential to clarify the st... Physical training and functional reserve in winter physical education teaching can optimize the energy consumption of the body,regulate cardiopulmonary function,and stabilize emotions.It is essential to clarify the strategies of winter physical training and functional reserve as well as the existing issues in college physical education teaching,which subsequently improves students’physical functions and achieves comprehensive development goals. 展开更多
关键词 College physical education teaching WINTER physical training Functional reserve
下载PDF
Optimization and Characterization of Combined Degumming Process of Typha angustata L. Stem Fibers
4
作者 Sana Rezig Foued Khoffi +2 位作者 Mounir Jaouadi Asma Eloudiani Slah Msahli 《Journal of Renewable Materials》 EI CAS 2024年第6期1071-1086,共16页
Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to... Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%). 展开更多
关键词 Typha angustata L.stems fibers combined treatment optimization process desirability function chemical and physical properties morphological structure
下载PDF
Progress on the melanoidins produced by the Maillard reaction of fermented food and traditional Chinese medicine
5
作者 Guang-Zhen Cao Si-Yi Zhang +4 位作者 Yao-Song Yang Qing He Xin-Xian Song Fei Long Teng Peng 《Food and Health》 2024年第4期10-18,共9页
FMs(Food-borne melanoidins)are brown high molecular weight polymers formed by the Mailiard reaction between carbohydrates and nitrogen-containing compounds during the processing of food or Traditional Chinese Medicine... FMs(Food-borne melanoidins)are brown high molecular weight polymers formed by the Mailiard reaction between carbohydrates and nitrogen-containing compounds during the processing of food or Traditional Chinese Medicine(TCM),and are widely found in food-borne products such as TCM concoctions,bakery,brewing,soy sauce,ferment and other food-borne products.FMs not only have a variety of biological activities,such as antioxidant,antibacterial,immunomodulation,regulation of intestinal flora,etc.,and can change the color,aroma and taste of food.The diversity of its components has become a research hotspot at home and abroad in recent years,with a wide range of application prospects.Therefore,this paper summarizes the existing information on FMs at home and abroad,mainly describes their preparation process,physicochemical properties,structural characteristics and functional activity research progress.Typical FMs,such as coffee,biscuits,wine and soy sauce in daily food,and Polygonatum,Perilla oil,Black ginseng,and Red jujube in T,were highlighted.Summarising the current status of research between the chemistry and pharmacodynamics of relevant FMs and presenting challenges and future recommendations for melanoidin research.In future research on FMs,one should pay more attention to basic research,especially isolation and purification and generation mechanisms,to further demonstrate the biological activity of FMs in vivo and in clinical trials.Thus,the potential value of its existence is deeply exploited to meet the needs of technology,production and health. 展开更多
关键词 Food-borne melanoidins physical and chemical properties Structure Functional activities Application prospects
下载PDF
Theoretical Investigations on Electronic Structures and Absorption Spectra of Unsymmetrical Metal-coordinated Neo-confused Porphyrin in Various Solvents 被引量:1
6
作者 曹洪玉 郝娟媛 +3 位作者 司端惠 唐乾 郑学仿 郝策 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第8期1223-1232,共10页
Though the photo-physical properties of free base porphyrin are attractive, there are still problems for the materials with weak and narrow range absorption of visible light. The unsymmetrical neo-confused porphyrin d... Though the photo-physical properties of free base porphyrin are attractive, there are still problems for the materials with weak and narrow range absorption of visible light. The unsymmetrical neo-confused porphyrin derivatives were introduced as novel materials for the improvement of photo-chemical and photo-physical properties. The density function theory(DFT)and time dependent density function theory(TDDFT) were applied to calculate the absorption spectrum of unsymmetrical neo-confused porphyrin(N-CP) and metal-coordinated N-CP in various solutions. The Ni and Zn coordinated neo-confused porphyrin dipole moment values are smaller than the values of prototype porphyrin(Pro P) and N–CP. According to the electrophilicity index ω, Ni coordinated N–CP(Ni–N–CP) is susceptible to the polarity of solvents, while the Zn coordinated derivative(Zn–N–CP) is more immune to the solvent environment. Unlike the Gouterman's four frontier orbital model of common porphyrin materials, the electron transitions of N–CPs and metalcoordinated N–CPs from H–2 or lower molecular orbitals also contribute to ultraviolet and visible absorption. Most of oscillator strength f values of Zn–N–CP are significantly higher than the values of Ni–N–CP, which reflects the higher absorption intensity of Q and Soret bands. The maximum wavelength at 702.2 nm in vacuum drew our attention to the novel material. The broad absorption range, intense red-shifted Q band and higher stability in solvents suggest that N–CPs, especially Zn–N–CP, can be one class of new candidate dye-sensitized materials. 展开更多
关键词 metal-coordinated neo-confused porphyrin asymmetry C-N swapstrategy photo-physical property density function theory
下载PDF
Thermal physical properties and key influence factors of phase change emulsion 被引量:9
7
作者 XUHui YANGRui +3 位作者 ZHANGYinping HUANGZhe LINJia WANGXin 《Chinese Science Bulletin》 SCIE EI CAS 2005年第1期88-93,共6页
Latent functionally thermal fluids (LFTF) are a novel kind of heat storage and heat transfer fluids that in- clude phase change microcapsule slurry and phase change emulsion (PCE). They have much greater apparent spec... Latent functionally thermal fluids (LFTF) are a novel kind of heat storage and heat transfer fluids that in- clude phase change microcapsule slurry and phase change emulsion (PCE). They have much greater apparent specific heats and higher heat transfer abilities in the phase change temperature range than conventional single-phase heat transfer fluids such as water. Thus they are advantageous in the field of the convective heat transfer enhancement and energy transport. In this paper, some thermal physical prop- erties such as viscosity, fusion heat and apparent specific heat (cp) are measured, and the influences of some factors (such as selection of surfactants, preparation method, temperature, mixing ratio of surfactants and mass concentration of phase change material) on them are discussed. The study shows that: 1) the viscosity of the PCE prepared in the present work is lower than that reported in the literature; 2) its ap- parent specific heat value for the phase change temperature region is high and proportionally increases with the concentration of phase change material. 展开更多
关键词 相变材料 相变乳液 热流体 热物理性质 粘性 表观比热 双相流体
原文传递
Improoing Finges' Functiong of Mental Students by Combining Medicine with Education and Physical Education
8
作者 LIU Shaozeng (54 years old, associate professor) 《北京体育大学学报》 CSSCI 1995年第S2期67-73,共7页
The improvement of fingers’functions is important for mentalretarded students to enhance their living,learning and working abilities. The study showed through experiments that adopting a method combining medicine wit... The improvement of fingers’functions is important for mentalretarded students to enhance their living,learning and working abilities. The study showed through experiments that adopting a method combining medicine with physical education and education can lead to a better improvement of fingers’ functions of the mental retarded students. 展开更多
关键词 FINGER function moving range of FINGER joint means COMBINING MEDICINE with physical education and education
原文传递
高职院校美育教育与瑜伽教学融合探索 被引量:1
9
作者 王焕 《当代体育科技》 2024年第7期171-174,共4页
全面加强和改进学校体育和美育融合,是加快推进新时代教育现代化的关键工作,既是对国家文件精神的积极响应,又是对学校体育教学的优化改革,其不仅能促进学生身体素质的发展,而且还能提高学生的审美素养。该文以大学生身心发展特点和心... 全面加强和改进学校体育和美育融合,是加快推进新时代教育现代化的关键工作,既是对国家文件精神的积极响应,又是对学校体育教学的优化改革,其不仅能促进学生身体素质的发展,而且还能提高学生的审美素养。该文以大学生身心发展特点和心理需求为出发点,将瑜伽教学和美学教育目标相结合,从学校体育和美育教育融合发展的困境出发,结合瑜伽美育教育的环境美、语言美、运动美、艺术美、形式美的功能,提出树立美育理念、明确目标要求、优化教学方法、精准评价考核的实现路径,使学生掌握瑜伽体式和练习方法,促进学生素质教育的优质均衡发展,提升学生良好的审美素养。 展开更多
关键词 体育和美育融合 影响因素 美育功能 实现路径
下载PDF
体育课程对工程应用型人才培养隐性功能的实现
10
作者 刘朝晖 陈红星 《江苏工程职业技术学院学报》 2024年第1期86-91,共6页
工程应用型人才培养需要打破学科壁垒,注重对学生集成知识结构与知识迁移能力的训练。高校公共体育课具有“学科群”与“跨学科”的特性,能让学生生成具身经验、获得默会知识、提升实践智慧、形成职业认知,而要充分发挥这些隐性功能,高... 工程应用型人才培养需要打破学科壁垒,注重对学生集成知识结构与知识迁移能力的训练。高校公共体育课具有“学科群”与“跨学科”的特性,能让学生生成具身经验、获得默会知识、提升实践智慧、形成职业认知,而要充分发挥这些隐性功能,高校公共体育课可使用个人和社会责任课程模式、体适能教育课程模式、运动教育课程模式、合作学习课程模式、拓展教育课程模式、动作教育课程模式等,使课程与工程教育的人才培养目标同频共振,注重人才培养的知识、能力、情感、态度及价值观的整体性,形成各学科互补、实践环节推动、专业素养跨界拓展、个性化柔性培养的教育模式。 展开更多
关键词 工程教育 体育课程 隐性功能 知识迁移
下载PDF
基于高校体育教学中功能性训练的应用
11
作者 王伟 王广亨 刘新平 《湖北开放职业学院学报》 2024年第20期177-178,182,共3页
为了实现新形势下德智体美劳综合型人才培养目标,高校应肩负起学生成长成才的重任,大力促进高校体育教育事业的发展。本文以高校体育课程为对象,简要阐述了功能性体育训练的结构功能和应用价值,并对高校体育教学中的功能训练内容加以分... 为了实现新形势下德智体美劳综合型人才培养目标,高校应肩负起学生成长成才的重任,大力促进高校体育教育事业的发展。本文以高校体育课程为对象,简要阐述了功能性体育训练的结构功能和应用价值,并对高校体育教学中的功能训练内容加以分析,提出行之有效的应用策略及发展建议,旨在促进大学生身体机能和运动素养的提升,提高高校体育课堂教学质量,以供参考。 展开更多
关键词 高等院校 体育教学 功能性训练 应用及建议
下载PDF
体育育人在高校立德树人体系中的功能定位及实现路径研究
12
作者 韩雪峰 《高教学刊》 2024年第14期99-102,共4页
体育课程在高校教学体系中具有重要地位。高校体育不仅在提高学生身体素质方面发挥巨大作用,而且作为一种具有广泛影响的文化形态,通过与德育教学相结合将其立德树人的功能充分呈现出来,为德育教育提供有效途径和载体。基于此,高校应在... 体育课程在高校教学体系中具有重要地位。高校体育不仅在提高学生身体素质方面发挥巨大作用,而且作为一种具有广泛影响的文化形态,通过与德育教学相结合将其立德树人的功能充分呈现出来,为德育教育提供有效途径和载体。基于此,高校应在立德树人体系下结合自身实际,把体育课程和体育文化巧妙结合,落到实处,在强健大学生体魄的同时,培养大学生成为具有爱国主义和积极主动精神、公平公正意识、合作精神和社会道德的社会主义接班人,从而充分发挥高校体育在立德树人体系中的功效。通过相关文献的查阅,对高校在立德树人体系下体育育人的功能及实现路径进行探讨,为高校体育育人功能的实现提供参考。 展开更多
关键词 立德树人 体育育人 高校体育 育人功能 育人路径
下载PDF
立德树人背景下人体机能课程思政的探索
13
作者 龙香娥 陈慧玲 +1 位作者 张玲 高虹 《卫生职业教育》 2024年第15期29-32,共4页
为更好地落实立德树人根本任务,从明确课程思政培养目标、整合教育资源、选择实施路径及优化评价机制等方面,进行人体机能课程思政建设的探索与实践。
关键词 高职 人体机能 课程思政
下载PDF
中国古代糯稻的功用
14
作者 王宇丰 《古今农业》 2024年第3期15-22,14,共9页
糯稻在今天是小宗作物,在古代却有着重要而广泛的用途。在自然属性层面,熟糯米的优异理化性质使其成为理想的酿料、食物、粘合剂及药物,糯禾则因抗逆性强而成为一种先锋作物;在社会属性层面,糯米的神圣文化内涵又使其成为必需的祭品、... 糯稻在今天是小宗作物,在古代却有着重要而广泛的用途。在自然属性层面,熟糯米的优异理化性质使其成为理想的酿料、食物、粘合剂及药物,糯禾则因抗逆性强而成为一种先锋作物;在社会属性层面,糯米的神圣文化内涵又使其成为必需的祭品、礼品和标志物。梳理古代糯稻的功用对理解古代糯稻的栽培和加工颇有裨益。 展开更多
关键词 糯稻 功用 理化性质 文化意义
下载PDF
户外科考教学对提升高校学生体质健康水平的影响研究
15
作者 夏宏武 方文发 《延边大学学报(自然科学版)》 CAS 2024年第3期145-148,共4页
为探究高校开展户外科考活动对大学生体质健康的影响,以安徽中医药大学第五届科考队的100名队员为研究对象,利用定量统计法探讨了户外科考活动对大学生的身体素质的影响效果.研究表明,科考训练可显著提升大学生的身体机能和身体素质指标... 为探究高校开展户外科考活动对大学生体质健康的影响,以安徽中医药大学第五届科考队的100名队员为研究对象,利用定量统计法探讨了户外科考活动对大学生的身体素质的影响效果.研究表明,科考训练可显著提升大学生的身体机能和身体素质指标.根据研究结果,提出了高校开展户外科考2点建议.研究结果可促进国内高校开展户外科考活动,并为提升大学生体质健康提供参考. 展开更多
关键词 户外科考 高校体育 学生体质 身体机能指数
下载PDF
稀土元素的生物学功能及其在动物生产中的应用 被引量:1
16
作者 邓蒙蒙 高慧 +1 位作者 刘建新 王迪铭 《动物营养学报》 CAS CSCD 北大核心 2024年第2期789-797,共9页
稀土元素是一类具有独特理化性质的金属元素。大量研究表明,稀土元素可通过增强酶活性、抑菌作用、调节免疫功能、改善胃肠道微生物区系等方式,参与动物代谢和生理调控,最终改善动物的生产性能和健康状况等。由于稀土元素的高化学活性,... 稀土元素是一类具有独特理化性质的金属元素。大量研究表明,稀土元素可通过增强酶活性、抑菌作用、调节免疫功能、改善胃肠道微生物区系等方式,参与动物代谢和生理调控,最终改善动物的生产性能和健康状况等。由于稀土元素的高化学活性,所以其通常以有机或无机形式应用到生产实践中。本文综述了稀土元素的理化性质、生物学功能以及不同形式稀土元素在动物生产中的应用情况,并对未来稀土元素作为饲料添加剂的应用做出展望,以期为利用稀土元素作为新型饲料添加剂配制饲粮提供全面的理论参考,并为饲粮补饲稀土元素在动物实际生产过程中的应用提供广泛的实践参考。 展开更多
关键词 稀土元素 理化性质 生物学功能 动物生产
下载PDF
富硒小米蛋白的理化性质、功能特性及结构研究 被引量:1
17
作者 李琳 金丽娜 +2 位作者 郭佩佩 刘敦华 傅婧 《食品与发酵工业》 CAS CSCD 北大核心 2024年第3期259-267,共9页
该文以普通小米蛋白(common millet protein,MP)为对照,采用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)、傅里叶红外光谱(Fourier infrared spectroscopy,FT-IR)、扫描电... 该文以普通小米蛋白(common millet protein,MP)为对照,采用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)、傅里叶红外光谱(Fourier infrared spectroscopy,FT-IR)、扫描电镜(scanning electron microscopy,SEM)等方法并测定溶解度(solubility,PS)、持水性(water holding capacity,WA)、乳化性(emulsification capability,EC)等指标对富硒小米蛋白(selenium-rich millet protein,SMP)的理化性质、功能特性及结构进行分析。结果表明,MP与SMP的硒含量分别为0.08、0.63 mg/kg;MP与SMP的必需氨基酸(essential amino acid,EAA)含量分别占总氨基酸含量的51.101%、53.529%;EAA与非必需氨基酸(non-essential amino acids,NEAA)的比值为1.045、1.152;2种小米蛋白分子质量均分布在10~70.2 kDa;随着pH升高,小米蛋白的PS、WA、起泡性(froth capability,FC)、起泡稳定性(froth stability,FS)、EC均呈现先下降后上升趋势,而乳化稳定性(emulsion stability,ES)正好相反;随着温度升高,小米蛋白的PS、WA、持油性(oil-holding property,FA)、FC、FS、EC、ES均呈现先上升后下降趋势(P<0.05);SEM结果显示MP表面有不规则凸起,而SMP表面光滑平整;FT-IR显示2种小米蛋白峰型一致,SMP位置略有后移,同时SMP的α-螺旋、β-折叠、β-转角含量较MP分别高出5.532、2.885、5.506个百分点,无规则卷曲含量则低于MP,说明SMP的结构有序性优于MP。该研究结果为SMP产品的开发利用提供重要理论依据。 展开更多
关键词 富硒小米蛋白 功能特性 理化特性 结构表征
下载PDF
冠突散囊菌对茶叶品质的影响及其发酵茶的功能活性研究进展 被引量:3
18
作者 周祎炜 燕飞 +5 位作者 曲东 李新生 谢侗 闫瑞瑞 陈小华 赵璇 《茶叶通讯》 2024年第1期16-22,共7页
冠突散囊菌(Eurotium Cristatum)是茯砖茶“发花”过程中形成的优势菌种,是目前研究较深入的发酵类真菌。冠突散囊菌发酵茶叶后可改善茶汤滋味与香气,赋予茶叶多种活性生理功能。综述了冠突散囊菌的分离与鉴定、对茶叶品质的影响以及冠... 冠突散囊菌(Eurotium Cristatum)是茯砖茶“发花”过程中形成的优势菌种,是目前研究较深入的发酵类真菌。冠突散囊菌发酵茶叶后可改善茶汤滋味与香气,赋予茶叶多种活性生理功能。综述了冠突散囊菌的分离与鉴定、对茶叶品质的影响以及冠突散囊菌发酵茶的功能活性等方面的研究结果,旨在为冠突散囊菌发酵茶新产品的开发与应用提供参考。 展开更多
关键词 冠突散囊菌 茶叶 发酵 理化特性 呈味物质 品质 功能活性
下载PDF
油茶根腐病根际土壤、根系内真菌群落结构和多样性分析
19
作者 杨娅琳 吴峰婧琳 +5 位作者 陈健鑫 武自强 刘丽 张东华 马焕成 伍建榕 《中国农业科技导报》 CAS CSCD 北大核心 2024年第7期121-135,共15页
为明确患根腐病的油茶在不同病情等级下根系和根际土壤内真菌群落组成、多样性、功能特征及与环境因子的关系,以德宏州梁河县的油茶为研究对象,利用高通量测序技术对5个病情等级的油茶根系及根际土壤内真菌的转录间隔区(internal transc... 为明确患根腐病的油茶在不同病情等级下根系和根际土壤内真菌群落组成、多样性、功能特征及与环境因子的关系,以德宏州梁河县的油茶为研究对象,利用高通量测序技术对5个病情等级的油茶根系及根际土壤内真菌的转录间隔区(internal transcribed spacer,ITS)序列进行测序。结果表明,染病油茶根系及根际土壤内的真菌群落多样性(Shannon指数)降低,根系中真菌总OTUs(operational taxonomic units)、特有OTUs和丰富度(Chao1指数)呈先增加后减少的趋势;根际土壤中染病油茶真菌群落的均匀度和丰富度上升。门水平上,子囊菌门(Ascomycota)和担子菌门(Basidiomycota)为根系及根际土壤中共同的优势菌门,球囊菌门(Glomeromycota)和被孢囊门(Mortierellomycota)在根系中丰度表现为逐级递减的趋势。属水平上,患病后油茶根系内树状孢属(Dendrosporium)、暗双胞属(Cordana)、Matsushimamyces、无柄盘菌属(Pezicula)、黑孢盘属(Melanconium)的丰度明显上升。油茶林下土壤真菌群落结构的主要影响因子为速效钾、有机质、pH、速效磷,真菌群落与环境因子联合分析结果表明,部分有益菌和磷含量呈正相关,部分病原菌和钾含量呈负相关。FUNGuild功能分析表明,油茶根系及根际土壤中真菌以腐生型为主,健康油茶中共生营养型真菌丰度最高,染病后逐渐降低;从Ⅱ级病害以后的油茶根系内植物病原功能群开始成为优势功能群。综上所述,油茶患病后真菌的多样性减少,根系内部分有益真菌丰度减少,植物病原菌和腐生菌增加,丛枝菌根真菌的定殖在调节油茶病健关系中发挥着重要的作用。针对德宏州梁河县的油茶基地,需要多施钾肥和磷肥,减少氮肥的施用,可提高部分有益菌的丰度,降低病原菌的丰度,从而减轻油茶根腐病的发生。 展开更多
关键词 油茶根腐病 真菌多样性 群落结构 土壤理化性质 FUNGuild功能
下载PDF
黑木耳黑色素研究进展
20
作者 姚秀鸽 郭燕 +5 位作者 韩闯 王能爽 田爽 朱加楠 周舒扬 马银鹏 《食用菌学报》 CSCD 北大核心 2024年第2期127-134,共8页
黑木耳(Auricularia heimuer)黑色素是天然无毒的生物色素,具有抗辐射、抗氧化和保护肝脏等作用,被广泛应用于食品、医药和化妆品等领域。笔者综述了黑木耳黑色素提取和纯化方法、结构表征、理化性质以及生物学功能,展望了其在食品、医... 黑木耳(Auricularia heimuer)黑色素是天然无毒的生物色素,具有抗辐射、抗氧化和保护肝脏等作用,被广泛应用于食品、医药和化妆品等领域。笔者综述了黑木耳黑色素提取和纯化方法、结构表征、理化性质以及生物学功能,展望了其在食品、医药和化妆品领域的应用,并阐述了当前存在问题及今后研究方向,以期为黑木耳黑色素研究和应用提供参考。 展开更多
关键词 黑木耳 黑色素 提取 理化性质 生物学功能
下载PDF
上一页 1 2 34 下一页 到第
使用帮助 返回顶部