Results 41 to 50 of about 2,233 (164)

Mesoporous Hollow Carbon Spheres/Nanofibers Anchored With Conductive Bimetallic for Efficient Microwave Absorption

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT To break electromagnetic wave absorption (EMA) tech's single‐attenuation bottleneck, enhancing multi‐wave absorption synergy in composites is key for microstructure design. This study uses mesoporous hollow carbon spheres to make metal nanospheres with cobalt, iron, and nickel nanoparticles, then encapsulates them via electrospinning into a ...
Wei‐Lian Zhang   +10 more
wiley   +1 more source

Closed reflux for simultaneous determination of COD and DOC in water by spectrophotometric method and potentiometric analysis(闭管回流分光光度法和电位分析联合测定水体中的化学需氧量和可溶性有机碳)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2008
采用密闭试管消解水样,用分光光度法比色测定COD,并将有机碳转化为二氧化碳,利用三乙醇胺(TEA)吸收CO2以pH计间接测定DOC.应用该方法测定了印染废水、医疗废水、地表水、葡萄糖水溶液等4种样品的COD和DOC,结果表明该方法具有良好的重现性 ...
TENGFu-hua(滕富华)   +1 more
doaj   +1 more source

Engineering 2D Materials for High‐Current‐Density Electrocatalytic Water Splitting

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Water electrolysis is a key method for sustainable hydrogen production, using water as an abundant resource. However, efficient and stable operation at high current densities remains challenging due to energy losses, catalyst degradation, and limited ion–electron transport.
Tianqi Guan   +8 more
wiley   +1 more source

耕作制度对紫色水稻土有机碳累积及矿化动态的影响

open access: yesShuitu Baochi Xuebao, 2011
以稻田长期定位试验为平台,研究常规平作(中稻-冬水田)、垄作免耕(中稻-冬水田)、垄作免耕(中稻-油菜)和水旱轮作(中稻-油菜)4种耕作制度对紫色水稻土有机碳累积及矿化动态的影响。结果表明:实行不同耕作制度均能提高土壤有机碳密度,以垄作免耕(中稻-油菜)最佳。不同耕作制度实施20年后,农田0-10 cm表层土壤有机碳密度已趋于稳定,垄作免耕会提高10-20 cm和20-40 cm土层有机碳密度,而水旱轮作各土层有机碳密度均低于其他耕作处理 ...
彭娟   +5 more
doaj  

Electronic Modulation of Cu Sites via Iron Incorporation in Cu5FeS4 Bimetallic Sulfide for High‐Efficiency Oxygen Reduction Reaction

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT The sluggish kinetics of the oxygen reduction reaction (ORR) necessitate developing oxygen electrodes with enhanced electrocatalytic activity for practical zinc–air battery applications. In this study, an iron‐doped copper sulfide electrocatalyst (CuFeNS‐PNC) anchored on metal–organic framework‐derived carbon substrates was designed, featuring
Taichong Chitboonyakasem   +4 more
wiley   +1 more source

退耕还林地在植被恢复初期碳储量及分配格局研究

open access: yesShuitu Baochi Xuebao, 2007
利用标准样方法研究了川西最主要的两种退耕还林植被(苦竹林和桦木林)在恢复初期生态系统碳储量、碳素密度以及空间分配特征.结果表明:(1)苦竹不同器官碳素密度为0.348 5~0.518 6 gC/g,桦木不同器官碳素密度为0.451 9~0.513 7 gC/g;(2)苦竹林林下枯落物的碳素密度为0.341 7 gC/g,桦木林林下枯落物的碳素密度为0.395 3 gC/g;(3)不同植物器官的碳储量分配与各器官的生物量显著相关.苦竹林分中竹秆生物量占48.87%,其碳储量占53.06 ...
黄从德, 张健, 邓玉林, 杨万勤
doaj   +2 more sources

Coral‐Like Yolk–Shell‐Structured CoNi@Void@C Microspheres for Enhanced Microwave Absorption, Photothermal, Anti‐Corrosion, and Radiation Shielding Properties

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Considering the multiple challenges faced by stealth coatings in complex service environments, the development of multifunctional integrated microwave absorbing materials (MAMs) that combine efficient electromagnetic (EM) attenuation with environmental tolerance has become an urgent need. In this work, coral‐like CoNi@Void@C microparticle (MP)
Jiale Wu   +8 more
wiley   +1 more source

青藏高原土壤有机碳储量与密度分布 [PDF]

open access: yes
采用全国第二次土壤普查数据结合作者的实测数据,利用1∶100万土壤数据库对青藏高原土壤有机质层、土壤矿质层及整个剖面的土壤有机碳密度和土壤有机碳储量分别进行了估算。结果表明:青藏高原的平均土壤有机碳密度约为C7.2kgm-2,较前人的C8.01~19.05kgm-2全国平均土壤有机碳密度偏低。青藏高原总的土壤有机碳储量约为18.37Pg,其中有机质层土壤有机碳储量约占38.14%,矿质层土壤有机碳储量则占61.86%。中国科学院知识创新工程重要方向项目(KZCX3-SW-339-04 ...
周才平   +4 more
core  

High‐Performance Sodium‐Ion Capacitors With Kinetics‐Matched Characteristics Enabled by N/O/S‐Doped Homologous Carbon Electrodes Derived From a Single Precursor

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Sodium‐ion capacitors (SICs) offer high energy and power density with long cycle life, but developing kinetically compatible electrodes remains challenging. This work developed a simple and sustainable strategy to synthesize homologous carbon electrodes from the inner shells of durian husks (ISDH) for high‐performance SICs.
De‐Bing Yan   +7 more
wiley   +1 more source

喀斯特石漠化区不同土地利用方式下土壤有机碳分布特征

open access: yesShuitu Baochi Xuebao, 2017
为探究喀斯特土壤有机碳分布特征及其对人为干扰的响应,挖掘了2 854个土壤剖面,采集了22 786个土壤样品,分析了贵州省不同土地利用方式下土壤有机碳分布规律;并结合贵州省石漠化防治规划,初步估算了石漠化防治工程的土壤碳增汇贡献。结果表明:贵州省土壤有机碳呈现含量高、密度小的特征。表层土壤(0—20 cm)有机碳平均含量25.07 g/kg,平均密度仅为4.27 kg/m2。不同用地类型土壤表层有机碳含量大小为灌木林地>乔灌木林地>灌草地>乔木林地>弃耕地与荒地>草地>水田>园地>旱地与坡耕地 ...
黄先飞, 周运超, 张珍明
doaj  

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