Results 21 to 30 of about 10,427 (161)

紫色土区植物篱篱前淤积带与篱下土坎土壤抗蚀性研究

open access: yesShuitu Baochi Xuebao, 2020
为探究紫色土坡地植物篱篱前淤积带与篱下土坎土壤抗蚀性的差异及变化规律,选取遂宁市水土保持试验站10°新银合欢植物篱小区(T1)、10°和15°香根草植物篱小区(T2和T3)进行研究。研究小区布设有上、中、下坡篱带,分别采集篱前淤积带和篱下土坎(下坡无)的表土样,测定有机质含量、水稳性团聚体和微团聚体组成,运用主成分分析法对土壤抗蚀性进行分析。结果表明:同一篱带,土壤有机质含量、团聚度和团聚状况均是篱前淤积带高于篱下土坎,土壤水稳性团聚体含量和抗蚀性综合指数则反之,篱下土坎的抗蚀性综合指数是篱前淤积带的1.
王针针   +5 more
doaj  

切向电场主导下C4F7N/CO2混合气体中环氧复合材料表面电荷积聚特性及机理研究

open access: yesGaoya dianqi, 2023
气固界面的电荷积聚问题是诱发沿面闪络的重要原因,而当前C4F7N/CO2混合气体中电荷积聚特性的相关研究还不够充分。为研究C4F7N/CO2混合气体中表面电荷积聚特性及机理,本文通过指型电极构建极不均匀电场,测量了环氧复合材料在C4F7N/CO2混合气体中的表面电荷分布特性;进一步的,为理清表面电荷来源及迁移特性,测量了冲击电压下C4F7N/CO2混合气体中材料表面电位,比较了附加背板电极前后的表面电荷分布。研究表明,C4F7N/CO2混合气体与SF6中表面电位分布形态相似 ...
李金殊   +5 more
doaj  

Research on Culture of Qi and Literture in the Han Dynasty [PDF]

open access: yes, 2016
本文主要讨论齐地文化与两汉文学的关系问题,由引言和正文两部分组成。引言部分主要探讨地域文化与两汉文学的关系,并对本文的参考资料、选题依据和采用的理论方法进行了梳理、说明。在对上述问题进行讨论后,本文认为探析齐地文化与两汉文学的关系不仅是可行的,而且有利于我们加深对两汉文学产生和发展规律的认识。 正文部分共分为五章。第一章重点考察两汉齐地文化的形成历程,并界定了与之相关的概念。认为齐地文化在历经先秦时期的漫长发展和秦朝时的短暂挫折以后,已做好了在两汉时期再度辉煌的准备 ...
宫伟伟
core  

Multiscale Study of a Synergistic System in Carbon‐Coated Multimetal‐Based Selenides Toward Rapid and Highly Stable Sodium Storage

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The development of sodium‐ion batteries (SIBs) is limited by slow charge transfer kinetics and large material volume changes caused by the large radius of Na+. Leveraging the excellent physicochemical properties and unique heterostructures of metal selenides, ultrafine hetero‐CuFeSe2‐CoSe2 nanoparticles are in situ wrapped by ...
Ying Zhu   +5 more
wiley   +1 more source

矿粮复合区煤累积对土壤团粒结构的影响

open access: yesShuitu Baochi Xuebao, 2019
为理解煤对土壤结构的影响,以土壤煤累积现象普遍的焦作矿粮复合区为研究区,选取3种不同程度的煤累积土壤(低累积、中累积和高累积)为研究对象,不含煤的土壤为对照,通过测定0-40 cm土层深度范围的水稳性团聚体组成,并采用分形维数(D)、平均重量直径(MWD)、几何平均直径(GMD)和大团聚体破坏率(PAD)作为团粒结构的评价指标,探讨煤累积对土壤团聚体组成与稳定性的影响。结果表明:煤在土壤中累积可以促进水稳性微团聚体向大团聚体转化,降低团聚体的分形维数,提高团聚体稳定性。深层(20-40 cm ...
聂小军   +5 more
doaj  

Recent Advances in Chemical Bath Deposition of Electron and Hole Transport Layers for Perovskite Solar Cells and Modules

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The development of high‐efficiency, stable, and scalable perovskite solar cells/perovskite solar modules (PSCs/PSMs) highly depends on the performance and cost‐effectiveness of functional layers such as electron transport layers (ETLs) and hole transport layers (HTLs).
Baochang Wang   +11 more
wiley   +1 more source

气—固绝缘分界面电荷积聚模型及数值计算

open access: yesGaoya dianqi, 2017
气体绝缘金属封闭输电线路(gas-insulated transmission line,GIL)绝缘子在直流电压长期作用下,会积聚表面电荷,引起绝缘子沿面闪络电压降低,导致闪络事故。因此研究绝缘子在长期直流耐受下的表面电荷积聚现象,对气—固界面在直流电压下的电荷积聚机理进行分析,建立更为完善的表面电荷积聚模型,具有重要的理论意义和工程价值。笔者基于3种已有的表面电荷积聚模型、分界面电荷弛豫方程和更为普适的稳态电荷密度方程,利用微元法对盆式绝缘子表面电荷分布进行了数值计算。结果表明 ...
杜乾栋   +6 more
doaj  

Microphase separation of mixtures of two diblock copolymers(两嵌段共聚物共混体系的相分离研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2009
用耗散粒子动力学方法(DPD)研究了由两种不同成分组成的两嵌段共聚物组成的混合体系在纳米尺度下的自组装行为.两种嵌段共聚物的聚合度相同,在稳定状态下,纯嵌段共聚物1呈层状有序结构,纯嵌段共聚物2呈无序或六角柱状结构.DPD研究表明,在两者混合体系中,随着嵌段共聚物2体积分数的增加,嵌段共聚物1只出现了层状的有序相,而嵌段共聚物2则呈现出从球状相到柱状相再到层状有序相的有趣变化,随着嵌段共聚物2对称性的增强,其形成的有序相所占的体积分数区域越小.同时,通过混合体系单体密度分布曲线和末端距分布情况 ...
LUOJin(罗进), HELin-li(何林李)
doaj   +1 more source

The Clinical Signifcance of Expression of ERCC1 and PKCalpha in Non-small Cell Lung Cancer [PDF]

open access: yes, 2010
Background and objective Excision repair cross-complementing 1 (Excision-Repair Cross-Complementing 1, ERCC1), an important member of the DNA repair gene family, plays a key role in nucleotide excision repair and apoptosis of tumor cells.
Guangming LI   +6 more
core   +1 more source

Phosphorus‐Doping Drives the Formation of a Pt‐Skin@PtFe Alloy Catalyst With Modulated d‐Band Center for Oxygen Reduction

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Platinum (Pt)‐based catalysts are crucial for the commercialization of hydrogen/metal air batteries, but they suffer from Pt scarcity, high cost, and nanoparticle dissolution/agglomeration, mainly leading to performance degradation. We address this by synthesizing a PtFe alloy catalyst (PtFe–PA–NC) via a phytic acid (PA) assisted pyrolysis ...
Chenyang Shu   +9 more
wiley   +1 more source

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