Results 21 to 30 of about 102,530 (104)

梯级水电站开发对香溪河悬浮颗粒物粒径及浓度的影响

open access: yes, 2008
通过对香溪河悬浮颗粒物粒度及浓度的实验分析,研究梯级水电站开发对河流悬浮颗粒物的影响,结果表明:(1)香溪河干流悬浮颗粒物粒径由上游到中游逐渐减小,并且在无水电站干扰时颗粒物粒径减小幅度较大;(2)从进水口至出水口河段,水电站悬浮颗粒物粒径总体变化不显著;(3)水电站从进水口河段至出水口河段,总悬浮颗粒物浓度(CTPM)在某些位置有所增加,有机颗粒物浓度(CPOM)无明显变化 ...
董正举   +5 more
core   +2 more sources

煤矸石对盐碱土壤绿化和土壤微生物的影响

open access: yesShuitu Baochi Xuebao, 2018
为探究煤矸石对盐碱土壤绿化的改良效果和对土壤微生物的影响,将不同用量(0,10%,20%,30%,40%,50%)和不同粒径(小粒径5 mm,以及小中大粒径等比例的混合粒径)煤矸石施用于盐碱土壤,进行紫花苜蓿盆栽试验,测定紫花苜蓿株高、生物量以及土壤微生物量和酶活性指标。结果表明,不同粒径煤矸石处理的土壤微生物量碳氮,土壤的脲酶、过氧化氢酶、脱氢酶活性,以及紫花苜蓿株高、生物量均随着煤矸石用量的增加呈先增大后降低的趋势,混合粒径、小粒径、中粒径、大粒径煤矸石处理的盐碱土上述指标分别在20%,20%,30%
孔涛   +5 more
doaj  

Predictive M‐Site Design of MAX‐Derived CoNi Composites: Dual‐Scale TaC + L12 Strengthening Enabled by Rare Metal Ta

open access: yesRare Metals, Volume 45, Issue 9, September 2026.
ABSTRACT In MAX‐phase‐derived metal–matrix composites, the M‐site element simultaneously governs carbide chemistry and matrix precipitate stability, yet it has traditionally been selected empirically rather than from a predictive criterion linking M‐site choice to carbide chemistry, matrix alloying, and L12 stability; moreover, the reaction pathway ...
Wei Yang   +8 more
wiley   +1 more source

Time‐Efficient Columnar‐to‐Equiaxed Transition via High Magnetic Field Processing

open access: yesRare Metals, Volume 45, Issue 9, September 2026.
ABSTRACT The need to simplify processing routes and improve processing efficiency motivates the development of time‐efficient methods for inducing the columnar‐to‐equiaxed transition (CET) during solidification while tailoring material performance. Conventional multistep CET approaches are time‐consuming and often struggle to simultaneously regulate ...
Chendong Zhao   +12 more
wiley   +1 more source

Unveiling Entropy‐Driven Hard‐Tough Synergy Mechanisms in High‐Entropy Carbonitride Ceramics

open access: yesRare Metals, Volume 45, Issue 9, September 2026.
ABSTRACT High‐entropy ceramics manifested promise for extreme environments, yet their phase stability and mechanical synergy mechanisms remain elusive. Herein, entropy‐difference carbonitrides, including (TaTiV)CN, (TaTiVNb)CN, and (TaTiVNbHf)CN, were designed and consolidated via spark plasma sintering.
Long Zhao   +6 more
wiley   +1 more source

Ultrasound‐Driven Dual Piezocatalytic–Electrical Scaffold Synergistically Promotes Osteoporotic Bone Healing

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT The regeneration of osteoporotic bone defects is severely hampered by compromised endogenous healing capacity, demanding advanced strategies that actively orchestrate pro‐osteogenic microenvironments. Here, we report an integrated, self‐powered osteo‐regenerative system that uniquely leverages a dual ultrasound‐responsive piezoelectric ...
Bing Tan   +6 more
wiley   +1 more source

浊度法用于测量悬浮液中微量固体颗粒浓度

open access: yesGongye shui chuli, 2008
采用浊度法检测含有微量细小的分子筛颗粒和金属镍颗粒的悬浮液中微量固体颗粒浓度,并对相关因素的影响进行了研究。结果表明:在实验范围内,悬浮液微细颗粒的浓度与悬浮液浊度成线性关系;对微细颗粒悬浮液,采用d32(Sauter直径)作为平均直径比采用中位直径d50更能反应出粒径因素对浊度的影响。
孟庆功   +3 more
doaj   +2 more sources

中国5种典型土壤的侵蚀泥沙粒径分布特征

open access: yesShuitu Baochi Xuebao, 2018
通过天然降雨试验,研究我国5种典型土壤的侵蚀泥沙团粒和单粒粒径分布以及泥沙各级团粒的机械组成特征。2013—2014年汛期(6—9月),监测红壤、紫色土、黄绵土、褐土和黑土径流小区的降雨产流事件,收集侵蚀泥沙样品,利用湿筛法和吸管法测定其团粒和单粒粒径分布;同时,筛选出泥沙各级团粒样品,进一步测定其单粒粒径组成。结果表明:(1)侵蚀泥沙粒径分布是土壤质地和降雨强度综合作用的结果,团粒粒径分布更适合作为表征泥沙输移的指标;(2)5种土壤的侵蚀泥沙皆表现出粉团(0.002~0.05 mm)和黏团(<0 ...
郝燕芳, 刘宝元
doaj  

Insights Into the Temperature‐Dependent Oxidation Mechanism of Metallic Cerium in H2O‐N2 Atmospheres

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Metallic cerium (Ce), a widely used surrogate for actinide metals, enables mechanistic studies of reactions in complex gas environments under controlled and safer laboratory conditions. Here, the oxidation behavior of Ce in H2O‐N2 mixed atmospheres was investigated from 200°C to 350°C using in situ thermogravimetry–mass spectrometry, in situ X‐
Kun Huang   +10 more
wiley   +1 more source

电力外绝缘污秽颗粒等效模型和粒径分布探讨

open access: yesDianci bileiqi, 2013
为今后实现自然积污规律研究和防污的差异化,对污秽颗粒等效简化模型、大气总悬浮颗粒物(TSP)的粒径分布函数、绝缘表面污秽主要化学成分对应TSP的粒径分布进行了综述和分析,认为可以污秽颗粒可等效简化为球体,使用空气动力学粒径衡量其粒径;建立TSP粒径分布函数拟合模型;分析认为化学成分Ca2+、SO42-、Cl-、SiO2、Al2O3在TSP中的粒径主要分布在1.810μm,010μm,1.810μm,30-40μm,40μm50μm的范围内,最后对自然积污规律研究和防污的差异化进行了展望。
李恒真   +5 more
doaj  

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