Results 41 to 50 of about 3,218 (153)

Comparison of volatile compounds between the green and yellow ripening fruits of four guava species [PDF]

open access: yes
[Objective] This study aimed to analyze the differences in volatile compounds between the mature green and mature yellow fruits of guava. [Methods] The volatile compounds in 4 kinds of guava fruits during the mature green and mature yellow were detected ...
LIN Zhixin   +4 more
core   +1 more source

降雨条件下黄土坡面溶质随地表径流迁移实验研究

open access: yesShuitu Baochi Xuebao, 1993
根据西北黄土坡面溶质随地表径流迁移的特点,研制了黄土坡面溶质随地表径流迁移实验系统,并利用此系统进行了室内模拟实验,根据实验资料分析了土壤中各种离子随地表径流迁移特性,详细分析了土壤溶质随地表径流迁移机理。
王全九 秦务光 等
doaj  

洞庭湖水系江湖流域物质侵蚀及其迁称与归宿

open access: yesShuitu Baochi Xuebao, 1995
依据洞庭湖水系江湖流域中的主要水文站实测的悬移质模数(1951-1990年)和离子径流模数(198501988年)以及计算资料,运用自然地理学的理论、方法研究了物质侵蚀特性以及物质迁移与归宿的动态变化,同时从地理环境状况的角度上分析了影响物质物质侵蚀迁移的主导因素。
李景保 刘晓清
doaj  

Preparation and Photocatalytic Activity of Composite Nanofibers Based on Electrospinning TiO2 [PDF]

open access: yes, 2016
TiO2由于具有许多优良的物理化学特性而在光催化领域备受关注。然而,由于其能带达到3.2eV,只能被波长在380nm以下的光激发;同时,激发产生的光生载流子的复合速率高,导致量子效率低下。这两个方面的缺点限制了TiO2在工业上的广泛应用。因此,针对以上不足,本文制备了TiO2纳米纤维并对其进行改性,以达到提高自然光利用率和抑制光生电子空穴复合的目的。 本文采用静电纺丝法制备了纳米尺寸的TiO2纤维。着重讨论了PVP添加量与纺丝液供给速率对前驱体纤维形态的影响,确定了获得TiO2纳米纤维的静电纺丝工艺参数。
王建树
core  

氧化锌非线性陶瓷的老化机理

open access: yesDianci bileiqi, 1986
通过观察氧化锌非线性陶瓷的伏安特性、介电特性及热激电流,研究交直流偏置而引起的老化现象。由结果可以断定:直流偏置引起的现象是由于富氧化铋晶界层和肖特基势垒过渡层的离子迁移,非对称的肖特基势垒畸变所致;而交流偏置所引起的现象是因为肖特基势垒过渡层的离子迁移,对称的肖特基势垒畸变所致。还叙述了氧化锌非线性陶瓷的热击穿寿命与偏置条件,如偏置温度及偏置电压的关系。
Kazuo Eda, 苟雅江
doaj  

miR-130b-5p下调胰岛素样生长因子-1抑制人绒毛膜滋养层细胞迁移及侵袭的作用及机制

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2022
目的探究微小RNA 130b-5p(miR-130b-5p)靶向胰岛素样生长因子-1(IGF-1)对人绒毛膜滋养层细胞(HTR8/SVneo)迁移及侵袭的影响。方法将HTR8/SVneo细胞分为对照组、miR-NC组、miR-130b-5pmimics组、miR-130b-5pmimics+pcDNA3.1组和miR-130b-5pmimics+pcDNA3.1-IGF-1组,双荧光素酶报告基因检测miR-130b-5p和IGF-1的靶向关系;采用实时荧光定量PCR检测HTR8 ...
相萌, 张旭东
doaj  

辽宁设施栽培土壤盐分累积变化规律研究

open access: yesShuitu Baochi Xuebao, 2005
对辽宁省主要设施栽培地区土壤盐分累积变化规律的凋查研究结果表明:(1)设施栽培土壤盐分含量和电导率较露地土壤有明显增加,且变化幅度较大,是露地的2.0~6.0倍。沈阳、北宁两地设施土壤的盐分含量分别为1347.48mg/kg(CV=59.3%),1274.25mg/kg(CV=40.5%)。(2)设施土壤连续种植到4年左右为盐分累积的高峰期,此时土壤的平均含盐量为1861.28mg/kg,EC值为0.53mS/cm,已超过所种作物的生育障碍临界点(EC〉0.5mS/cm)。此后 ...
余海英 李廷轩
doaj   +2 more sources

Analysis of Physicochemical Quality and Flavor Differences of Five Commercially Available Tiger Nut Oils with Different Processes Based on GC-IMS Technique [PDF]

open access: yes
In order to evaluate the differences in physicochemical quality and flavor of commercially edible tiger nut oil, gas chromatography-ion mobility spectroscopy (GC-IMS) combined with principal component analysis was used to compare the volatile compounds ...
Changqing WEI   +5 more
core   +1 more source

Analysis of Postharvest Quality and Volatile Substances of Different Tomato Varieties [PDF]

open access: yes
In order to clarify the differences of postharest quality and volatile substances of different tomato varieties, the volatile substances of different tomato varieties ('567' 'Provence' 'Youshi No.3' 'Warrior 808' 'Meiqi') were determined by gas ...
Di WU   +6 more
core   +1 more source

Study of Solid Oxide Fuel Cell Electrolytes Based on Lanthanum Gallate [PDF]

open access: yes, 2006
Sr、Mg双掺杂的镓酸镧具有高氧离子电导率、高氧离子迁移数与较好的稳定性,是目前研究广泛的中温固体氧化物燃料电池(ITSOFC)电解质材料。本文采用交流阻抗和Hebb-Wagner极化法研究了氧化铝掺杂的La0.9Sr0.1Ga0.8Mg0.2O3-d和钴掺杂的La0.8Sr0.2Ga0.8Mg0.2O3-d材料的电导特性,利用热重分析法考察了钴掺杂的La0.8Sr0.2Ga0.8Mg0.2O3-d中钴离子的价态以及氧空位浓度随氧分压的变化,并用电动势法测定了系列镓酸镧材料的平均氧离子迁移数 ...
吴玲丽
core  

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