Results 31 to 40 of about 31,003 (237)

Preparation and Characterization of BN Coating on SiC Fibers by Carbothermal Reduction [PDF]

open access: yes, 2016
本论文以硼酸三甲酯(trimethylborate—TMB)蒸气为硼源、NH3气为氮源,采用碳热还原氮化法在SiC纤维表面制备BN涂层。首先,SiC纤维与Cl2气反应表面生成碳化物衍生碳(carbide-derivedcarbon—CDC)层,然后,CDC层与TMB蒸气及NH3气在1300C发生碳热还原氮化反应,生成BN涂层。采用FT-IR、XPS、XRD、AES、SEM、TEM、电阻率测试、单丝拉伸试验等系统地研究了所得BN涂层的组成、结构和性能。研究发现 ...
袁梦娇
core  

Preparation and properties of desulfurization gypsum-slag hydraulic cementitious materials [PDF]

open access: yes, 2012
Desulfurization gypsum is the desulphurization products of wet FGD process in coal-fired power plants. However, it has not been widely used by far. In order to expand the application scope of desulphurization gypsum, desulphurization gypsum-industrial ...
Li, Gang, Liu, Xiaoqin, Qin, Honggen
core   +1 more source

Policy Effectiveness in Managing Drug Shortages: Evidence From South Korea (2015–2024)

open access: yesWorld Medical &Health Policy, EarlyView.
ABSTRACT Drug shortages represent a growing policy challenge for healthcare systems worldwide. This study investigates actual drug shortage events in South Korea from 2015 to 2024, using a “Shortage Occurred vs. Shortage Non‐Occurred” framework to distinguish real‐world disruptions from administrative classifications.
Seung‐Rae Yu
wiley   +1 more source

材料力学性能不均匀模式对对接接头结构性能分析的影响

open access: yesJianzhu Gangjiegou Jinzhan, 2017
经历不均匀热过程影响的对接焊接接头,呈现不均匀力学性能。在对对接焊接接头疲劳等分析过程中,应考虑不均匀力学性能。根据对接焊接接头分区和力学性能分布,提出了3种对接焊接接头不均匀力学性能分布模式:二区模式、五区模式和连续化模式。采用有限元方法分析材料力学性能不均匀模式对对接焊接结构性能分析的影响。采用3种模式结合已有试验数据,建立了不同精细化程度的有限元模型并进行有限元分析。研究结果表明:分布模式对结果会产生很大的影响,模式越精细,屈服荷载、极限荷载和屈服位移、极限位移就越小 ...
甘结良, 彭洋, 董军
doaj  

平行医学:从医学的温度到智慧的医学

open access: yes智能科学与技术学报, 2021
如何将智能科技与医疗健康结合,在传统医学和现代医学的基础上创建更加高效的智慧医学,是一项意义重大的历史性任务。针对医学的科学性、人文性和社会性等复杂问题,集复杂性医学、跨学科医学和系统智能医学多个角度于一体,利用人工社会建模、计算实验分析、平行执行管控,提出平行医学的基本概念、框架和流程,力图建立将医学研究的小数据演化生成医学大数据,再凝练、验证形成医学深智能的医学数据智能生成过程。
王飞跃
doaj  

Efficient Simulation Methods for Reinforced Concrete Columns with Encased Steel in High-rise Building Structures [PDF]

open access: yes, 2016
型钢混凝土柱在建筑结构中往往是主要的承重构件之一,使用合适的数值模型分析其力学性能对高层结构抗震分析有重要的意义。本文综述了目前文献中已有的低含钢率恢复力模型相关研究,分析了其理论、计算流程和算法,并在通用有限元软件OpenSees中编程实现。本文详细推导了模型中基本参数的确定方法,并用于模拟实际高层建筑结构中的型钢混凝土柱。首先,本文用恢复力模型模拟了单根型钢混凝土柱的试验,通过对比验证了模型的精度,研究了其计算效率。其次,本文将恢复力模型用于理想32层高层结构中的单排型钢混凝土构件静、动力分析中 ...
曾志弘
core  

Scaling from microsite to landscape to resolve litter decomposition dynamics in globally extensive drylands

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Decomposition is the transformation of dead organic matter into its inorganic constituents. In most biomes, decomposition rates can be accurately predicted with simple mathematical models, but these models have long under‐predicted decomposition in globally extensive ...
Heather L. Throop   +8 more
wiley   +1 more source

Arbuscular mycorrhizal fungus reshapes the rhizosphere microbiome of alfalfa in response to above‐ground attack by aphids and a fungal plant pathogen

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Plants assemble beneficial rhizosphere microbiomes through a ‘cry for help’ mechanism upon pathogen or insect herbivore attack. The arbuscular mycorrhizal fungi (AMF) can influence the composition of microbial communities in the plant rhizosphere. However, their impacts
Yingde Li   +6 more
wiley   +1 more source

Investigation of Microstructure, Mechanical Properties and Irradiation Behaviors of Nuclear Application Steels [PDF]

open access: yes, 2015
在核能领域应用的关键材料的服役条件非常苛刻,需要在辐照、高温、腐蚀、受应力、热循环等极端条件下长期稳定工作,并按照可预期的方式老化、失效。堆内构件的性能与特性决定了核能可以达到的安全水平。中国从美国西屋公司引进、吸收与消化AP1000核电技术,以形成具有自主知识产权的核电技术,并在此过程中着重对一系列核能关键用材料进行了相关研发。本论文以国产SA-182F304钢、304SS钢、CNST1钢、CNST2钢和CNSS3钢为研究对象,对候选钢的微观结构、微观化学、力学行为和抗辐照性能进行了详细研究 ...
陈芙梁
core  

Global drivers of the conservation–invasion paradox

open access: yesConservation Biology, EarlyView.
Abstract The conservation–invasion paradox (CIP) refers to a long‐term phenomenon wherein species threatened in their native range can sustain viable populations when introduced to other regions. Understanding the drivers of CIP is helpful for conserving threatened species and managing invasive species, which is unfortunately still lacking. We compiled
Yanhua Hong, Zhiyong Yuan, Xuan Liu
wiley   +1 more source

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