检索结果-南通市图书馆

An experimental and numerical study of packing, compression, and caking behaviour of detergent powders

Particuology 2014年第1期12卷 2-12页

作者： Subhash c.Thakur Hossein Ahmadian Jin Sun Jin Y.Ooi School of Engineering University of Edinburgh Newcastle Innovation centre Procter and Gamble Technical Centre Ltd

This paper presents an experimental and numerical study of the packing, compression, and caking behaviour of spray dried detergent （SDD） powders with a two-fold aim： an experimental process of observation and evaluation of the packing, compression and caking behaviour of SDD powders, and a numerical approach based on discrete element modelling （DEM）. The mechanical properties, including the stress-strain response and the corresponding porosity change as a function of consolidation stress in a confined cylinder, the stress-strain response during unconfined shearing and the cake strength as a func- tion of consolidation stress, were evaluated and compared for different SDD powders using an extended uniaxial tester （Edinburgh Powder Tester - EPT）. The experiments using EPT showed excellent repro- ducibility in the measurement of packing, compression and caking behaviour and were therefore very useful for describing the handling characteristics of these powdered products including screening new products and different formulations. It was found that the sample with higher moisture had lower bulk porosity but higher compressibility and cake strength. The porosity, compressibility and cake strength were found to vary across different size fractions of the same sample. The larger sieve-cut samples had higher initial bulk porosity, compressibility and cake strength. It is revealed that moisture plays a sig- nificant role in packing, compression, and shearing behaviour of the powder. Three-dimensional DEM modelling using a recently developed elasto-plastic adhesive-frictional contact model showed that the contact model is able to capture the detergent behaviour reasonably well and can be used to model complex processes involving these powders.

关键词： discrete element methodPowder flowcohesive materialUniaxial testPlasticitycontact model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure and mechanical properties of similar and dissimilar metal gas tungsten constricted arc welds:maraging steel to 13-8 Mo stainless steel

引用

Defence Technology（防务技术） 2019年第1期15卷 111-121页

作者： c.V.S.Murthy A.Gopala Krishna G.M.Reddy Defence Research and Development Laboratory Jawaharlal Nehru Technological University Defence Metallurgical Research Laboratory

maraging steel (250) and 13-8 Mo stainless steel plates were joined by gas tungsten constricted arc welding(GTcAW) process in similar and dissimilar metal combinations using 13-8 Mo stainless steel filler wire. The similar and dissimilar metal welds made in solutionized condition were subjected to standard post weld hardening treatments direct ageing at 485 ℃, soaking for 31/2 hours followed by air cooling(ageing treatment of maraging steel) and direct ageing at 510 ℃, soaking for 4 h followed by air cooling(ageing treatment of 13-8 Mo stainless steel). The joint characterization studies include microstructure examination, microhardness survey across the weldments and transverse weld tensile *** and dissimilar metal weldments responded to both the post weld ageing treatment. After post weld aging, increase in yield strength, UTS and slight reduction in % elongation of similar and dissimilar metal were observed. The observed tensile properties were correlated with microstructure and hardness distribution across the welds.

关键词： maraging steel(250) 13-8 Mo stainless steel Mechanical properties Microstructure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhancement of luminescence intensity and spectroscopic analysis of Eu^(3+) activated and Li^+ charge-compensated Bi_2O_3 nanophosphors for solid-state lighting

引用

Journal of Rare Earths 2019年第4期37卷 356-364页

作者： S.Ashwini S.c.Prashantha RamachANDra Naik H.Nagabhushana Department of Physics Channabasaveshwara Institute of Technology Research center Department of Science East West Institute of Technology Department of Physics New Horizon College of Engineering cNR Rao center for Advanced Materials Tumkur University

The present work reports the synthesis, characterization, photoluminescence and photocatalytic activity of Eu^(3+)(1 mol%-11 mol%) doped and Li^+(0.5 mol%-5 mol%) co-doped Bi_2 O_3 nanophosphors(NPs) by sonochemical method. The average particle size was estimated using powder X-ray diffraction(PXRD)and transmission electron microscopy(TEM) and is found to be in the range of 30-35 nm. The scanning electron microscopy(SEM) images were highly dependent on sonication time and concentration of epigallocatechin gallate(EGcG) bio-surfactant. The energy gap of doped and co-doped Bi_2 O_3 nanophosphors was estimated using Kubelka-Munk(K-M) function and is found to be in the range of2.9-3.08 eV. The effect of Li+ co-doping on luminescence of optimized Bi_2 O_3:Eu^(3+) was studied and is found about more than 3 fold enhancement of emission intensity. Judd-Ofelt parameters(Ω_2, Ω_4 and Ω_6).transition probabilities(A_T), quantum efficiency(η), luminescence lifetime(τ_(rad)), color chromaticity coordinates(cIE) and correlated color temperature(ccT) values were estimated from the emission spectra and are discussed in detail. The estimated cIE chromaticity co-ordinates are very close to the NTSc(National Television Standard committee) standard value of red emission. The synthesized NPs show excellent photocatalytic activity of acid red-88 under UV-light irradiation, which can degrade 98.1% in60 min. The decreasing electron-hole pair recombination rate with quick electron transfer ability is predominantly ascribed to the balance between crystallite size, morphology, band gap, defects, surface area, etc. These results show a light for the use of sonochemical route of Bi_2 O_3:Eu^(3+):Li^+ in solid state display and photocatalytic applications.

关键词： Bi2O3:Eu3+:Li+ Sonochemical Photoluminescence cIE n ccT Photocatalysis Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient HIV-1 in vitro reverse transcription: optimal capsid stability is required

引用

Signal Transduction and Targeted Therapy 2021年第2期6卷 195-196页

作者： Ryan c.Burdick Vinay K.Pathak Viral Mutation Section HIV Dynamics and Replication ProgramCenter for Cancer ResearchNational Cancer Institute at FrederickFrederickMD 21702USA

Recently,christensen et *** HIV-1 reverse transcription and integration in a cell-free system and found that viral double-stranded DNA that is capable of integration into a target plasmid DNA was efficiently synthesized within viral cores,indicating that the capsid protein shell plays an important role in viral genome replication.1 HIV-1 reverse transcriptase(RT)copies the viral genomic RNA into a double-stranded DNA,and HIV-1 integrase(IN)inserts the viral DNA into the host genome to form a *** RT and IN have been successfully targeted with potent antiretroviral drugs to inhibit these enzymes and treat patients infected with HIV-1,the causative agent of acquired immunodeficiency syndrome(AIDS).Despite decades of research,the molecular mechanisms of reverse transcription and integration in vivo are not fully characterized,in part because cell-free assays that efficiently and faithfully recapitulate the processes in the context of a virion have not been available。

关键词： al. drugs optimal

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

四氯合镉酸正十一烷铵的合成、晶体结构及低温热容

引用

化学学报 2012年第7期70卷 889-896页

作者：卢冬飞邸友莹窦建民 f山东省化学储能与新型电池技术重点实验室聊城大学化学化工学院聊城252059

合成了四氯合镉酸正十一烷铵配合物(c11H23NH3)2cdcl4(s)[简写:c11cd(s)].用X射线单晶衍射技术、化学分析和元素分析确定其晶体结构和化学组成.利用其晶体学数据计算出晶格能为:UPOT=908.18 kJ·mol-1.利用精密自动绝热热量计测定了它... 详细信息

合成了四氯合镉酸正十一烷铵配合物(c11H23NH3)2cdcl4(s)[简写:c11cd(s)].用X射线单晶衍射技术、化学分析和元素分析确定其晶体结构和化学组成.利用其晶体学数据计算出晶格能为:UPOT=908.18 kJ·mol-1.利用精密自动绝热热量计测定了它在78～395 K温区的低温热容,结果表明,该配合物在此温区出现两次连续的固-固相转变,计算出两次相变的峰温、摩尔焓及摩尔熵分别为:Ttrs,1=(321.88±0.07)K,ΔtrsHm,1=(37.59±0.17)kJ·mol-1,ΔtrsSm,1=(117.24±0.12)J·K-1·mol-1,Ttrs,2=(323.81±0.30)K,ΔtrsHm,2=(12.42±0.02)kJ·mol-1和ΔtrsSm,2=(38.36±0.09)J·K-1·mol-1.用最小二乘法将实验摩尔热容对温度进行拟合,得到热容随温度变化的多项式方程.用此方程进行数值积分,得到此温区每隔5 K的舒平热容值和相对于298.15 K时的热力学函数值.

关键词：四氯合镉酸正十一烷铵晶体结构晶格能低温热容固固相转变热力学函数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A simple and distinguished nebulizer approach to prepare cdS thin films

引用

Journal of Energy chemistry 2017年第3期26卷 398-405页

作者： M.Girish R.Sivakumar c.Sanjeeviraja R.Gopalakrishnan Department of Physics Alagappa UniversityKaraikudi 630003India Department of Physics Alagappa Chettiar College of Engineering and TechnologyKaraikudi 630003India Department of Physics Anna UniversityChennai 600025India

In this paper, we report the substrate temperature induced change in structural, optical, morphological,luminescence and photoelectrochemical properties of cdS films deposited by a simple and facile approach called nebulized spray pyrolysis technique. X-ray diffraction study confirmed the deposited cdS films belong to hexagonal wurtzite structure, with preferential orientation along c-axis,(002) direction perpendicular to the substrate plane. The crack free, uniform, and homogeneously distributed spherical particles are witnessed from AFM image. Various optical parameters like energy band gap, optical conductivity,refractive index, extinction coefficient, dielectric constants, and dispersion energy parameters of the films were evaluated. The strong band edge emission observed in the PL study may be attributed to the recombination of excitations and/or shallowly trapped electron-hole pairs. The first and second overtone of LO modes of cdS at 302 and 600 cm-1are observed in the Raman study. The photoelectrochemical properties of the films were also tested.

关键词： Semiconductors chemical synthesis Optical properties X-ray diffraction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Machine learning for exploring small polaron configurational space

引用

npj computational Materials 2022年第1期8卷 1183-1191页

作者： Viktor c.Birschitzky Florian Ellinger Ulrike diebold Michele Reticcioli cesare Franchini University of Vienna Faculty of Physics and Center for Computational Materials ScienceViennaAustria University of Vienna Vienna Doctoral School in PhysicsBoltzmanngasse 51090ViennaAustria Institute of Applied Physics Technische Universität Wien1040ViennaAustria Department of Physics and Astronomy’Augusto Righi’ Alma Mater Studiorum-Universitàdi BolognaBologna40127Italy

Polaron defects are ubiquitous in materials and play an important role in many processes involving carrier mobility,charge transfer and surface *** small polarons’spatial distributions is essential to understand materials properties and ***,the required exploration of the configurational space is computationally demanding when using first principles ***,we propose a machine-learning(ML)accelerated search that determines the ground state polaronic *** ML model is trained on databases of polaron configurations generated by density functional theory(DFT)via molecular dynamics or random *** establish a mapping between configurations and their stability,we designed descriptors modelling the interactions among polarons and charged point *** used the DFT+ML protocol to explore the polaron configurational space for two surface-systems,reduced rutile TiO_(2)(110)and Nb-doped SrTiO_(3)(001).The ML-aided search proposes additional polaronic configurations and can be utilized to determine optimal polaron distributions at any charge concentration.

关键词： configuration polaron charge

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particle shape characterisation and its application to discrete element modelling

引用

Particuology 2014年第1期12卷 80-89页

作者： Kenneth c.Williams Wei chen Sebastian Weeger Timothy J.Donohue centre for Bulk Solids and Particulate Technologies Newcastle Institute for Energy and Resources The University of Newcastle Georg-Simon-Ohm University Nuremberg TUNRA Bulk Solids Newcastle Institute for Energy and Resources The University of Newcastle

Increasing importance has been placed on particle shape implementation within discrete element mod elling （DEM） in order to more accurately reflect the nonspherical behaviour of the bulk material being handled. As computational resources grow, complex particle shapes are increasingly being modelled as the associated simulation times become more realistic to provide timely solutions. The objective of this research is to assess particle shape descriptors through a digital image segmentation technique, and to further implement particle shape parameters into generation of corresponding irregular shaped DEM particles. Separated and lumped particle images were analysed and reconstructed through the devel opment of two distinct methodologies. Subsequently, various particle shape descriptors were obtained using combinations of image segmentation algorithms, including mathematical morphology processing, thresholding, edge detection, region growing, region splitting and region merging. DEM particles were subsequently created using particle shape results obtained above. Shape parameters of DEM particles were then examined and validated against the real particle shape parameters.

关键词： Particle shapesParticle morphologyImage segmentationdiscrete element modelling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

cyclic performance and simplified pushover analyses of precast segmental concrete bridge columns with circular section

引用

Earthquake Engineering and Engineering Vibration 2016年第2期15卷 297-312页

作者： Bu Zhanyu Guo Jian Zheng Rongyue Song Jianwei George c.Lee Faculty of Architectural Civil Engineering and Environment Ningbo University college of civil Engineering and Architecture Zhejiang University of Technology Department of civil Structural and Environmental Engineering University at Buffalo

In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The preeast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation （ED） can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method （SPOM）, as well as a fiber model （FIBM） finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for preeast segmental columns with different design parameters.

关键词： precast concrete segmental column simplified pushover fiber model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

NanoHDA： A nanoparticle-assisted isothermal amplification technique for genotyping assays

引用

Nano Research 2017年第1期10卷 12-21页

作者： Abootaleb Sedighi christopher Oberc Vicki Whitehall Paul c. H. Li Department of chemistry Simon Fraser University Burnaby British Columbia VSA 1S6 Canada QIMR Berghofer Medical Research Institute 300 Herston Rd Brisbane Queensland 4006 Australia Department of chemical and Physical Sciences University of Toronto Mississauga Ontario LSL IC6 Canada

Isothermal methods, such as helicase-dependent amplification （HDA）, have an advantage over polymerase chain reaction for DNA amplification owing to their ease of operation. Here, we developed a new HDA method that is nanoparticle-assisted, termed nanoHDA. This method uses gold nanoparticles （AuNPs） to improve the sensitivity and specificity of the isothermal method. In HDA, the denaturation of DNA templates is mediated by helicases, but this method is limited by the low denaturation efficiency of helicases. In this report, AuNPs with preferential affinity for single-stranded DNA （ssDNA） were utilized to improve the denaturation efficiency of helicases. The same affinity property of nanoparticles can also enhance specificity by suppressing primer-dimer formation. This nanoHDA method was employed to genotype the KRAS gene in genomic DNA samples from colorectal cancer patients, as achieved by the hybridization of nanoHDA amplicons using the NanoBioArray chip.

关键词： gold nanoparticle isothermal DNAamplification helicase genotyping assay colorectal cancer single nucleotidepolymorphism KRAS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：