期刊文献+
共找到3,814篇文章
< 1 2 191 >
每页显示 20 50 100
Synthesis of PEG-Modified PET Masterbatch:Preparation of Low-Temperature Easy-Dyeing,High-Fastness PET Fibers Based on Phase Domain Size Regulation
1
作者 XIAO Yongbing XU Chaochen +5 位作者 SHEN Wufeng ZHANG Shengming CHEN Xiangling JI Peng WANG Chaosheng WANG Huaping 《Journal of Donghua University(English Edition)》 2025年第6期606-619,共14页
Polyethylene terephthalate(PET)fibers are the largest category of chemical fibers and are widely used.However,the dyeing of PET fibers requires high temperature and pressure(130℃and 0.2 MPa),and the dyeing process co... Polyethylene terephthalate(PET)fibers are the largest category of chemical fibers and are widely used.However,the dyeing of PET fibers requires high temperature and pressure(130℃and 0.2 MPa),and the dyeing process consumes huge amounts of energy.Existing studies have shown that the dyeing ability of PET is directly related to the size of the amorphous region,which determines the external conditions for dyeing.In this research,we synthesized a series of low-temperature easydyeing masterbatches,PET-co-polyethylene glycol(PETEG),using polyethylene glycol(PEG)with different number-average molecular masses Mn and additive amounts.The phase domain size of the amorphous region of PET fibers was regulated via the masterbatch method.The relationship between the phase domain size and dyeing performance was explored from three perspectives:the amount of masterbatch,type of masterbatch,and PEG relative molecular mass.The results indicate that the fiber sample with PEG(Mn=2000 g/mol)at a mass fraction of 20%modified masterbatch has a smaller crystalline lamellar thickness(5.59 nm)and a larger interlamellar amorphous layer thickness(6.43 nm).The increase in the long period and lamellar inclination angle results in a looser structure,allowing small molecule dyes to diffuse into the fibers more easily.The dye-uptake increases from 63.21%to 92.66%at 100℃with the addition of the masterbatch.Additionally,the dye-uptake of the modified fibers increases with the relative molecular mass of PEG and the mass fraction of the masterbatch.All modified fibers achieve a staining color fastness of grade 4 or higher.This research demonstrates a simple masterbatch method that enables atmospheric pressure dyeing and provides a practical solution for efficient,low-temperature,and low-energy dyeing of PET fibers. 展开更多
关键词 polyethylene terephthalate(PET)fiber polyethylene glycol(PEG) low-temperature dyeing phase domain size dye-uptake color fastness
在线阅读 下载PDF
Dyeing of S/J Cotton Knit Fabric with Natural Dye Extracts from Green Walnut Shells: Assessment of Mordanting Effect on Fastness Properties 被引量:1
2
作者 Zakaria   Md. Eanamul Haque Nizam +4 位作者 Md. Hasan Al Mamun Md. Abu Yousuf Ramjan Ali Lutfor Rahman Md. Raza Miah 《Journal of Textile Science and Technology》 2017年第2期17-30,共14页
In this study, aqueous extraction method is used because of its high extraction ratio, light fastness and also functional properties. In 1st phase, for dyeing S/J cotton knit fabric with green walnut power ferrous sul... In this study, aqueous extraction method is used because of its high extraction ratio, light fastness and also functional properties. In 1st phase, for dyeing S/J cotton knit fabric with green walnut power ferrous sulfate is considered as a mordant. In this study, three different mordanting methods such as pre-, meta-, and post-mordanting are conveyed the dyeing process with the state of metallic mordant and without metallic salt mordants. In 2nd phase, in dyeing for fixation ferrous sulfate was considered as mordants. Furthermore, the analysis and evaluation of each colour dyed material was done through following two terms for instance CIELAB (L*, a*, and b*) and K/S values. According to AATCC test methods, colour fastness to washing, crocking, perspiration of the dyed samples is determined whereas according to the ISO standard, the colour fastness to light was estimated and tested. When dyeing was carried out on S/J cotton knit fabric through considering optimum parameter like at 80&degC for 60 min and at pH 4 which showed optimum results. From the results we can see, very good wash fastness was obtained while there is no fading of the colour, whereas the outstanding and moderate level of colour fastness to light and crocking is achieved. 展开更多
关键词 Green WALNUT Shell Dye Extraction S/J Cotton Knit FABRIC Colour Strength fastness
暂未订购
Synthesis and Application of Polyurethane Modified Organic Silicone Wet Rubbing Fastness Improver
3
作者 仝东凤 刘学 +1 位作者 董朝红 刘杰 《Journal of Donghua University(English Edition)》 EI CAS 2015年第3期515-519,共5页
Polyurethane modified organic silicone was successfully prepared from hydroxyl-terminated polyether modified silicone,toluene-2,4-diisocyanate( TDI), and NaHSO3. The chemical structure of the polyurethane modified org... Polyurethane modified organic silicone was successfully prepared from hydroxyl-terminated polyether modified silicone,toluene-2,4-diisocyanate( TDI), and NaHSO3. The chemical structure of the polyurethane modified organic silicone was characterized by FT-IR and1H-NMR. The polymer film on the cotton surface was investigated by scanning electron microscopy( SEM) and the results showed that a thin polymer film was successfully formed. The FT-IR of treated cotton fabrics indicated that hydroxyl( OH) of cellulose fiber and isocyanate group( NCO)of the polyurethane modified organic silicone has formed covalent cross-linking. X-ray diffraction( XRD) analysis revealed that the crystalline region of treated cotton fabrics wasn't changed. The wet rubbing fastness of treated cotton fabrics was increased by approximately rating 1 on average. There was little change of DE values for the polyurethane modified organic silicone. The softness was improved significantly. 展开更多
关键词 modified silicone wet rubbing fastness cotton fabric APPLICATION
在线阅读 下载PDF
Color Fastness of Dyed Raw Linen Cloth Modified with Enzymes
4
作者 Bernava Aina Borisova Anna +1 位作者 Strazds Guntis Reihmane Skaidrite 《Journal of Chemistry and Chemical Engineering》 2014年第7期686-691,共6页
Green thinking looks to develop alternatives with higher environmental advantage that traditional materials or processes. The present experimental studies are directed to investigation of dyeing the linen fabric prepa... Green thinking looks to develop alternatives with higher environmental advantage that traditional materials or processes. The present experimental studies are directed to investigation of dyeing the linen fabric prepared with modification with enzymes. In the research, 1% and 2% solution of cellulase enzyme Beizym ENC-SB (garment auxiliary of enzymes mixture of CHT R. BEITLICH GmbH/BEZEMA AG) and pectinase Beisol PRO (enzymes mixture for cleaning cellulose fibers of CHT R. BE1TLICH GmbH) enzyme solutions were used. The main objective of this work is focus on results studies of enzyme influence on dyeing of flax fabric with direct Solphenyl dye triade Blue FGLE (economical, fairly good light fast blue, main trichromatic component for medium shades with high wash fastness), Scarlet BNLE (economical scarlet, main trichromatic component for medium to dark shades) 200%, and Yellow GLE (very bright neutral yellow, main trichromatic component for high wash fastness requirements). The dye-bath exhaustion, color fastness to rubbing and washing were estimated. The color parameters before and after tests were calculated. 展开更多
关键词 Raw linen cloth PECTINASE cellulase enzymes modification direct dye color fastness.
在线阅读 下载PDF
Fastness and Homogeneous Character of Coating Film on Big Telescope
5
作者 Qin Songnian, Li Rufeng, Gao Cai (Yunnan Observatory, The Chinese Academy of Sciences, Kunming 650011, China) 《天文研究与技术》 CSCD 1999年第S1期127-129,共3页
The paper reports the consideration for fastness and homogeneous character of coating film on large telescope. After coating film, we obtain that the optical homogeneous character of whole mirror is in 1/20 λ, and re... The paper reports the consideration for fastness and homogeneous character of coating film on large telescope. After coating film, we obtain that the optical homogeneous character of whole mirror is in 1/20 λ, and reflective rate is about 92%. We found that the thin film doesn’t tick to offset paper, and the film is still well after two years. 展开更多
关键词 fastness and Homogeneous Character of Coating
在线阅读 下载PDF
Target localization of abrasion-resistant color fastness samples based on YOLOv8 optimization and enhancement
6
作者 Yaling Cao 《Advances in Engineering Innovation》 2025年第5期98-105,共8页
To address the challenges in detecting abrasion-resistant color fastness samples–including limited sample instances,non-uniform shapes,and insufficiently distinct texture variations that compromise localization accur... To address the challenges in detecting abrasion-resistant color fastness samples–including limited sample instances,non-uniform shapes,and insufficiently distinct texture variations that compromise localization accuracy–this paper optimizes the detection framework through the integration of three key strategies:Global Attention Mechanism(GAM),Dynamic Sampling(DySample),and Adaptively Spatial Feature Fusion(ASFF),thereby enhancing detection accuracy and efficiency.Initially,Mosaic data augmentation is implemented to enrich dataset diversity and improve model robustness.Subsequently,the GAM attention mechanism is embedded into the backbone network to enhance target feature extraction capabilities.DySample replaces conventional upsampling methods in the neck network to achieve more effective feature reconstruction.Finally,the ASFF module is integrated into the Detect module within the head network to enable adaptively spatial weight learning for multi-scale feature map fusion.Compared with baseline algorithms,the improved framework demonstrates performance gains of 1.2%in Precision,3.0%in Recall,1.2%in mAP@0.5,and 13.5%in mAP@0.5:0.95.Experimental results validate the effectiveness of the proposed method,which maintains satisfactory performance across additional datasets,demonstrating strong robustness and superior generalization capability. 展开更多
关键词 target detection YOLOv8 abrasion-resistant color fastness sample convolutional neural network
在线阅读 下载PDF
FAST馈源舱-索塔耦联体系风雨振响应研究
7
作者 付兴 张鸿志 +1 位作者 李宏男 李庆伟 《工程力学》 北大核心 2026年第3期65-73,共9页
500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)的馈源舱位于140 m的高空,易受风荷载和雨荷载的影响,过大风雨振响应将会影响其正常运行。该文建立了精细化的馈源舱-索塔耦联体系有限元模型,开... 500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)的馈源舱位于140 m的高空,易受风荷载和雨荷载的影响,过大风雨振响应将会影响其正常运行。该文建立了精细化的馈源舱-索塔耦联体系有限元模型,开展模态分析,结果显示其基频很小且模态密集;馈源舱模型精细化程度对结构自振频率有较大影响。模拟风雨荷载时程,研究体系各构件风雨荷载中雨荷载的占比情况,发现考虑降雨后,整体荷载增幅显著,其中馈源舱所受荷载的增幅最大。计算了馈源舱-索塔耦联体系在风雨作用下的动力响应,结果表明:雨荷载对馈源舱结构位移响应的影响很大;雨荷载对结构总应力的影响较小;考虑降雨后,最大工作风速显著降低,且满足二次精调平台的最大工作风速均小于FAST设计工作风速(4 m/s),馈源舱的正常工作受到较大影响。 展开更多
关键词 FAST 风雨振响应 雨荷载 模态参数 动力分析
在线阅读 下载PDF
1例基于FAST HUGS BID模式的心源性休克病人的重症心脏康复管理
8
作者 李芳 裴祺 《全科护理》 2026年第1期187-190,共4页
总结1例基于FAST HUGS BID(快速拥抱bid)模式的心源性休克病人的重症心脏康复管理经验。心源性休克是心脏泵血功能不足导致组织灌注不足,通常需要强心药、机械支持等治疗,重症心脏康复管理需要特别关注循环稳定、器官灌注、并发症预防... 总结1例基于FAST HUGS BID(快速拥抱bid)模式的心源性休克病人的重症心脏康复管理经验。心源性休克是心脏泵血功能不足导致组织灌注不足,通常需要强心药、机械支持等治疗,重症心脏康复管理需要特别关注循环稳定、器官灌注、并发症预防等方面。病人突出的护理问题从胃肠营养尽早开始、镇痛、镇静、血栓的预防、床头抬高30°、应激性溃疡的预防、血糖的控制、自主呼吸试验、肠道管理、尽早拔除导管、抗生素降阶梯进行针对性护理评估并构建个性化重症心脏康复管理方案。经过积极救治和个性化护理,病人住院11 d,病情好转出院。 展开更多
关键词 FAST HUGS BID模式 心源性休克 重症心脏康复 护理
暂未订购
基于KANO-FAST模型的造纸设备管理APP设计研究
9
作者 王飞 吕明琪 陈鸿龙 《中国造纸》 北大核心 2026年第1期181-186,共6页
本研究将KANO模型与FAST方法相融合,通过问卷与访谈的方式收集行业需求,利用KANO模型对需求进行分类,并量化优先级(基本型、期望型、兴奋型)。在此基础上,结合FAST方法构建功能层级树,实现需求向模块化功能的精准转化。此外,设计出集成... 本研究将KANO模型与FAST方法相融合,通过问卷与访谈的方式收集行业需求,利用KANO模型对需求进行分类,并量化优先级(基本型、期望型、兴奋型)。在此基础上,结合FAST方法构建功能层级树,实现需求向模块化功能的精准转化。此外,设计出集成设备基本管理(基本需求)、异常上报(期望需求)及生产报工(兴奋需求)功能的APP。结果表明,用户对该APP的满意度达92%,设备维修效率提升了26个百分点。本研究设计的KANO-FAST模型,能够有效提升造纸设备管理APP的可用性设计效率,为工业设备管理提供兼具高可靠性、强创新性的解决方案,助力智能化转型。 展开更多
关键词 KANO模型 FAST方法 设备管理APP 智能化转型
在线阅读 下载PDF
小样本高校实验室事故致因语义分析与建模
10
作者 刘春祥 吴欣悦 +2 位作者 黄萍 余龙星 范传刚 《实验技术与管理》 北大核心 2026年第1期265-272,共8页
针对传统事故致因分析方法主观性强、耗时耗力的局限性,该文提出融合领域知识进行文本分析的事故致因分析方法。该文以73例高校事故文本为样本,运用Deepseek-reasoner模型对文本进行结构化构造,经TF-IDF算法处理提取了30个关键事故致因... 针对传统事故致因分析方法主观性强、耗时耗力的局限性,该文提出融合领域知识进行文本分析的事故致因分析方法。该文以73例高校事故文本为样本,运用Deepseek-reasoner模型对文本进行结构化构造,经TF-IDF算法处理提取了30个关键事故致因因素;结合实验室安全领域知识训练了Fast Text模型并对语义进行向量化处理,有效克服了小样本事故文本分析中语义稀疏性的弊端。随后通过K-means聚类分析事故致因因素向量,并与传统4M模型对比验证。结果显示,K-means聚类结果与4M模型划分结果高度一致,验证了融合领域知识的Fast Text模型在小样本条件下的可行性与有效性。研究表明,该方法可实现高校实验室事故致因因素的自动化识别、语义理解与分类,克服了小样本事故文本分析中语义信息稀疏性和领域适配性不足的问题,并具有向其他领域推广的潜力。 展开更多
关键词 实验室安全 事故分析 文本分析 Deepseek模型 Fast Text模型
在线阅读 下载PDF
FAST多相流产剖成像技术在页岩气水平井产出剖面的应用
11
作者 梁旭升 杨冬 曾翀 《石油机械》 北大核心 2026年第1期129-138,共10页
针对页岩气水平井开发中气-液两相流动态监测难题,提出了基于FAST(flow array sensing tool)多相流产剖成像仪的测井方法及评价方法。该方法突破传统测井局限,实现水平段全井眼流体动态成像,可精确量化各簇射孔段贡献率,为压裂效果评估... 针对页岩气水平井开发中气-液两相流动态监测难题,提出了基于FAST(flow array sensing tool)多相流产剖成像仪的测井方法及评价方法。该方法突破传统测井局限,实现水平段全井眼流体动态成像,可精确量化各簇射孔段贡献率,为压裂效果评估提供关键参数支撑。为验证FAST多相流产剖测井的应用效果及成果数据可靠性,在WD3-7井现场试验中,采用连续管传输技术实现成像仪精准下放,通过持续动态监测获得不同产量模式下流体流动的特征规律,总结气井产量高、中、低模式下气-液两相的典型流型。测试数据显示,在70000 m^(3)/d生产制度下,气液产量解释结果与地面计量仪数据符合率达95.83%。产剖数据与储层参数相关性分析表明,孔隙度、脆性指数及含气量与产气能力呈显著正相关,验证了“储层物性-压裂效果-产能”的耦合机制。现场应用结果表明,该技术可有效识别高产段与低产段,为水平井生产制度优化和重复压裂选层提供科学依据。研究成果对提升页岩气藏动态监测精度和开发效益具有重要工程价值。 展开更多
关键词 非常规油气 页岩气 页岩储层 水平井 多相流量扫描 FAST 产出剖面
在线阅读 下载PDF
科学教育引领的地理实践教学探索——以国家科普示范基地(FAST)为例
12
作者 周光发 吴娟 《地理教学》 北大核心 2026年第1期40-43,共4页
在学科教学中渗透科学教育内容,培育学生科学素养,是做好科学教育加法的重要举措。本文以国家科普示范基地(FAST)为实践教学场地,围绕FAST“建造目的、选址条件、观测原理、多维影响”四大主题构建学习任务群,按照“知识学习—实践操作... 在学科教学中渗透科学教育内容,培育学生科学素养,是做好科学教育加法的重要举措。本文以国家科普示范基地(FAST)为实践教学场地,围绕FAST“建造目的、选址条件、观测原理、多维影响”四大主题构建学习任务群,按照“知识学习—实践操作—综合应用”流程开展地理实践教学,帮助学生在学习探究中理解科学本质、掌握科学方法并形成科学思维,实现从“知识学习”到“素养培育”的进阶,进而打造依托科普基地开展地理实践教学的案例范式,为科学教育实践提供参考。 展开更多
关键词 科学教育 地理实践教学 国家科普示范基地(FAST) 跨学科融合
在线阅读 下载PDF
FAST法在明式圈椅家具结构中的构建研究
13
作者 王文智 刘俊 代安娜 《鞋类工艺与设计》 2026年第1期165-167,共3页
深入探讨明式圈椅的结构功能,以推动传统明式圈椅的创新发展。本文分析了明式圈椅的独特特点和文化价值,系统阐述了其功能的定义、分类及分级方法。利用FAST法,对明式圈椅的结构功能进行全面分析,依据用户需求对功能需求进行分级和排序... 深入探讨明式圈椅的结构功能,以推动传统明式圈椅的创新发展。本文分析了明式圈椅的独特特点和文化价值,系统阐述了其功能的定义、分类及分级方法。利用FAST法,对明式圈椅的结构功能进行全面分析,依据用户需求对功能需求进行分级和排序,建立了明式圈椅家具的FAST功能分析系统模型。通过该模型,揭示了明式圈椅在结构上的创新潜力,并基于此开展创新设计实践。这种设计方法不仅为挖掘和传承明式家具文化提供了新的思路,也为其现代化应用和创新设计奠定了理论依据和实践支持,具有重要的文化与设计意义。 展开更多
关键词 FAST法 明式家具 圈椅 家具设计
在线阅读 下载PDF
A 32‑channel charge‑sensitive amplifier for delay‑line readout of parallel plate avalanche counter array
14
作者 Yue‑Zhao Zhang Peng Ma +8 位作者 Zhuang‑Yu Lin Zhen‑Fei Tan Xing‑Chi Han Chen Liu Shuo Wang Da‑Peng Sun Zhi‑Quan Li En‑Hong Wang Shou‑Yu Wang 《Nuclear Science and Techniques》 2026年第1期164-179,共16页
A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete... A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition. 展开更多
关键词 Charge-sensitive amplifier Fast timing Parallel plate avalanche counter Delay-line Discrete components
在线阅读 下载PDF
Physics-constrained graph neural networks for solving adjoint equations
15
作者 Jinpeng Xiang Shufang Song +2 位作者 Wenbo Cao Kuijun Zuo Weiwei Zhang 《Acta Mechanica Sinica》 2026年第1期178-191,共14页
The adjoint method is widely used in gradient-based optimization with high-dimensional design variables.However,the cost of solving the adjoint equations in each iteration is comparable to that of solving the flow fie... The adjoint method is widely used in gradient-based optimization with high-dimensional design variables.However,the cost of solving the adjoint equations in each iteration is comparable to that of solving the flow field,resulting in expensive computational costs.To improve the efficiency of solving adjoint equations,we propose a physics-constrained graph neural networks for solving adjoint equations,named ADJ-PCGN.ADJ-PCGN establishes a mapping relationship between flow characteristics and adjoint vector based on data,serving as a replacement for the computationally expensive numerical solution of adjoint equations.A physics-based graph structure and message-passing mechanism are designed to endow its strong fitting and generalization capabilities.Taking transonic drag reduction and maximum lift-drag ratio of the airfoil as examples,results indicate that ADJ-PCGN attains a similar optimal shape as the classical direct adjoint loop method.In addition,ADJ-PCGN demonstrates strong generalization capabilities across different mesh topologies,mesh densities,and out-of-distribution conditions.It holds the potential to become a universal model for aerodynamic shape optimization involving states,geometries,and meshes. 展开更多
关键词 Adjoint method Deep learning Graph neural network Physics-constrained Fast aerodynamic analysis
原文传递
Enhanced mechanical strength and improved Li^(+)transport in PEO-based electrolytes via scalable bicontinuous PMIA porous membrane
16
作者 Honggui He Chuqing Tang +8 位作者 Zhaozhao Peng Mengjie Fan Ming Jiang Dan Li Weimin Kang Xiaoyin Wang Nanping Deng Lu Gao Xupin Zhuang 《Journal of Energy Chemistry》 2026年第1期183-197,I0005,共16页
The low ionic conductivity and poor mechanical strength of polyethylene oxide(PEO)-based electrolytes severely restrict their practical application.To address this problem,this work designs a scalable,high-strength(24... The low ionic conductivity and poor mechanical strength of polyethylene oxide(PEO)-based electrolytes severely restrict their practical application.To address this problem,this work designs a scalable,high-strength(24.3 MPa)bicontinuous porous poly(m-phthaloyl-m-phenylenediamine)(PMIA)membrane integrated into PEO/LiTFSI(PL),thus forming a PMIA/PEO/LiTFSI(PPL)composite electrolyte.Compared to the PL electrolyte,the PPL electrolyte reinforced by a bicontinuous porous PMIA membrane exhibits significantly enhanced mechanical strength,reaching 13.4 MPa.In addition,the amide groups on PMIA strongly coordinate with LiTFSI and form hydrogen bonds with PEO,promoting Li salt dissociation and reducing the Li^(+)migration barrier.This creates efficient,fast Li^(+)transport channels at the PMIA/PL interfaces,effectively promoting the uniform Li^(+)deposition and minimizing lithium dendrite formation.The PPL electrolyte achieves high ionic conductivity(1×10^(−4)S cm^(−1)at 30°C)and Li^(+)transference number(tLi^(+)=0.43).The assembled LiFePO_(4)/Li battery demonstrates excellent cycling stability,retaining 80%capacity after 2000 cycles at 2 C,while the Li/Li symmetric cell operates stably for over 900 h at 0.3 mA cm^(−2).Therefore,the scalable porous PMIA membrane effectively enhances both the mechanical strength and Li^(+)transport in PEO-based electrolytes,offering a viable strategy for their commercial-scale implementation. 展开更多
关键词 Solid-state lithium metal batteries PEO-based electrolytes PMIA Fast Li^(+)transport Mechanical strength
在线阅读 下载PDF
Exploring the effect of ethanol-water structuring on the transport properties of ethanol in porous silicas
17
作者 Jordan Ward-Williams Andrew Sederman +2 位作者 Michael Mantle Matthias Appel Lynn Gladden 《Magnetic Resonance Letters》 2026年第1期66-74,共9页
The transport properties of liquid mixtures confined within porous media can change significantly from those observed for bulk mixtures due to changes in the liquid structuring within the pore space.Here,pulsed field ... The transport properties of liquid mixtures confined within porous media can change significantly from those observed for bulk mixtures due to changes in the liquid structuring within the pore space.Here,pulsed field gradient NMR was used to measure the diffusion coefficient of ethanol in ethanol-water liquid mixtures confined within silicas with pore diameters of 6 nm and 3 nm as a function of composition.For liquids imbibed within the 6 nm pores,the composition dependence of the ethanol diffusion coefficient closely followed that of the bulk liquid mixture and the absolute diffusion coefficients were reduced by a tortuosity factor of 3,with a minor contribution due to liquid-surface interactions.For liquids imbibed within the 3 nm pores,the diffusion coefficient of ethanol decreased as the composition of ethanol within the pore space increased,and for single-component ethanol imbibition the effective tortuosity was 63.Fast field cycling NMR experiments showed that the diffusion behaviour was not controlled by an increase in ethanol adsorption strength.A geometric analysis of the pore space was consistent with a highly confined system in which most molecules interacted with the pore walls.Under such confinement,the liquid structuring within the bulk pore space did not reflect that of the bulk liquid mixtures,and the observed decrease in diffusion coefficient as ethanol composition increased was consistent with an increase in confinement due to the larger size of the ethanol molecule. 展开更多
关键词 ADSORPTION SILICA Binary liquid mixtures Diffusion Pulsed field gradient NMR Fast field cycling NMR
在线阅读 下载PDF
基于科学教育的地理跨学科主题学习活动设计——以国家科普示范基地(FAST)为例
18
作者 周光发 《中学地理教学参考》 2026年第3期61-66,共6页
文章结合科学教育与地理跨学科主题学习的实施背景,构建了基于科学教育的地理跨学科主题学习实施流程,并将国家科普示范基地(FAST)作为跨学科主题学习场地,开发了地理跨学科主题学习任务群并构建实施模式,根据制订的学习目标开展基于科... 文章结合科学教育与地理跨学科主题学习的实施背景,构建了基于科学教育的地理跨学科主题学习实施流程,并将国家科普示范基地(FAST)作为跨学科主题学习场地,开发了地理跨学科主题学习任务群并构建实施模式,根据制订的学习目标开展基于科学教育的地理跨学科主题学习实践活动,使科学教育与地理跨学科主题学习实现协同创新,让学生在跨学科主题学习中习得多学科知识,训练科学思维,提升核心素养。 展开更多
关键词 科学教育 地理跨学科主题学习 国家科普示范基地(FAST) 活动设计
原文传递
Fast identification of -emitting radionuclides based on sequential Bayesian approach
19
作者 Xuan Zhang Jian-Wei Huang +5 位作者 Lin-Jian Wan Jia-Cheng Liu Xiao-Le Zhang De-Hong Li Fei Tuo Zhi-Jun Yang 《Nuclear Science and Techniques》 2026年第2期1-15,共15页
The rapid identification of γ-emitting radionuclides with low activity levels in public areas is crucial for nuclear safety.However,classical methods rely on full-energy peaks in the integral spectrum,requiring suffi... The rapid identification of γ-emitting radionuclides with low activity levels in public areas is crucial for nuclear safety.However,classical methods rely on full-energy peaks in the integral spectrum,requiring sufficient count accumulation for evaluation,thereby limiting response time.The sequential Bayesian approach,which utilizes prior information and considers both photon energies and interarrival times,can significantly enhance the performance of radionuclides identification.This study proposes a theoretical optimization method for the traditional sequential Bayesian approach.Each photon is processed sequentially,and the corresponding posterior probability is updated in real time using a noninformative prior from the Bayesian theory.By comparing the posterior probabilities of the background and radionuclides based on the energy variance and time interval,the type of γ-rays can be identified(background characteristic γ-rays,Compton plateaus γ-rays,or radionuclide-specific characteristic γ-rays).By integrating the information from these multiple characteristic γ-rays,the presence and type of radionuclides were determined based on the final decision function and a set threshold.Based on theoretical research,verification experiments were conducted using a LaBr_(3)(Ce)detector in both low-and natural background radiation environments with typical radionuclides(^(137)Cs,^(60)Co,and ^(133)Ba).The results show that this approach can identify ^(137)Cs in 7.9 s and 8.5 s(source dose rate contribution:approximately 6.5×10^(−3)μGy/h),^(60)Co in 8.1 s and 9.8 s(approximately 4.8×10^(−2)μGy/h),and ^(133)Ba in 4.05 s and 5.99 s(approximately 3.4×10^(−2)μGy/h)under low and natural background radiation,respectively,with a miss rate below 0.01%.This demonstrates the effectiveness of the proposed approach for fast radionuclides identification,even at low activity levels and highlights its potential for enhancing public safety in diverse radiation environments. 展开更多
关键词 Sequential Bayesian approach Fast radionuclides identification LaBr_(3)(Ce)detector Low background radiation laboratory
在线阅读 下载PDF
Improving thermal stability and light fastness of Acid Red 114 by incorporating its anions in a ZnAl-layered double hydroxides matrix
20
作者 Haifeng Zhu Liren Wang +2 位作者 Pinggui Tang Yongjun Feng Dianqing Li 《Particuology》 SCIE EI CAS CSCD 2012年第4期503-508,共6页
Incorporation of anions of Acid Red 114 dye (1,3-naphthalenedisulfonic acid, 8-[2-[3,3'-dimethyl-4'-[2-[4- [l(4-methylphenyl)sulfonyl]oxy] phenyl]diazenyl] [1,1'-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium sal... Incorporation of anions of Acid Red 114 dye (1,3-naphthalenedisulfonic acid, 8-[2-[3,3'-dimethyl-4'-[2-[4- [l(4-methylphenyl)sulfonyl]oxy] phenyl]diazenyl] [1,1'-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium salt) (denoted as NPDA) into ZnAl-layered double hydroxides (LDHs) has been carried out by an anion- exchange method in an effort to improve their thermal stability and light fastness. After intercalation of NPDA anions, the interlayer distance of the LDHs increases from 0.87 to 2.18 nm, confirming their incorporation into the interlayer galleries of the LDHs host. Infrared spectroscopy and thermogravimetric analysis revealed the presence of host-vip interactions between LDHs layers and NPDA anions. The thermal stability of NPDA and ZnAI-NPDA-LDHs was compared by thermogravimetric-differential ther- mal analysis, UV-visible spectroscopy and infrared spectroscopy. It was found that the thermal stability of NPDA anions was markedly improved by incorporation into the ZnA1-LDHs matrix, while the light fastness was also enhanced. 展开更多
关键词 Layered double hydroxidesAnion-exchangeIncorporationThermal stabilityLight fastness
原文传递
上一页 1 2 191 下一页 到第
使用帮助 返回顶部