检索结果-南通市图书馆

Rheological and stability analysis of cement pastes incorporating silica-based wastes

Particuology 2024年第6期89卷 144-152页

作者： Julia da Rosa Martins Janaíde Cavalcante Rocha dachamir Hotza Luciano Senff Graduate Program in Materials Science and Engineering(PPGMAT) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program in Civil Engineering(PPGEC) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program in Chemical Engineering(POSENQ) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Department of Mobility Engineering Federal University of Santa Catarina(UFSC)Joinville89219-600SCBrazil

This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cement pastes and *** focus is to evaluate the impact of the zeta potential of cement particles and waste materials on the sedimentation speed,rheology,and hardening time of stabilized cement *** Cement II F 40,retarder additive,silica,and fly ash were used in the *** pastes were prepared,and during the stabilization period,their rheological properties and pH were *** zeta potential and sedimentation speed of the cement and waste particles were measured at the pH that the pastes presented during the entire stabilization *** the stabilization period,the pastes were subjected to the hardening time *** zeta potential analyses revealed diverse values for the different powder types,with the cement particles exhibiting a zeta potential of−3.0 mV,the silica particles exhibiting−10.5 mV,and the fly ash particles exhibiting−20.3 *** influence of the high zeta potential modulus was observed on the sedimentation speed,with the solution containing fly ash exhibiting a speed of 40.01μm/s,whereas the solution containing only cement exhibited a speed of 99.38μm/*** the pastes,the results indicate that the presence of fly ash particles with a significantly negative zeta potential led to a 16%reduction in hardening time compared to particles with a lower modulus of zeta *** tests showed that the inclusion of fly ash particles prevented the formation of *** the zeta potential influenced agglomerate formation and hardening time,it was found to have no effect on yield stress or viscosity.

关键词： Wastes Zeta potential Setting time Rheometry

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

Rock Mass Quality Rating Based on the Multi-Criteria Grey Metric Space

引用

Computer Modeling in Engineering & Sciences 2024年第9期140卷 2635-2664页

作者： Miloš Gligoric Zoran Gligoric saša Jovanovic Suzana Lutovac Dragan Pamucar Ivan Jankovic Faculty of Mining and Geology University of BelgradeBelgrade11000Serbia Faculty of Technical Sciences University of PrištinaKosovska Mitrovica38220Serbia Department of Operations Research and Statistics Faculty of Organizational SciencesUniversity of BelgradeBelgrade11000Serbia College of Engineering Yuan Ze UniversityTaoyuan City320315TaiwanChina

Assessment of rock mass quality significantly impacts the design and construction of underground and open-pit mines from the point of stability and *** study develops the novel Gromov-Hausdorff distance for rock quality(GHDQR)methodology for rock mass quality rating based on multi-criteria grey metric *** usually presents the quality of surrounding rock by classes(metric spaces)with specified properties and adequate interval-grey *** the distance between surrounding rock sample characteristics and existing classes represents the core of this *** Gromov-Hausdorff distance is an especially useful discriminant function,i.e.,a classifier to calculate these distances,and assess the quality of the surrounding *** efficiency of the developed methodology is analyzed using the Mean Absolute Percentage Error(MAPE)*** existing methods,such as the Gaussian cloud method,Discriminant method,Mutation series method,Artificial neural network(ANN),Support vector machine(SVM),Grey wolf optimizer and Support vector classification method(GWO-SVC)and Rock mass rating method(RMR)are used for comparison with the proposed GHDQR *** share of the highly accurate category of 85.71%clearly indicates compliance with actual values obtained by the compared *** results of comparisons showed that the model enables objective,efficient,and reliable assessment of rock mass quality.

关键词： Rock mass rating multi-criteria class metric space interval-grey numbers

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

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

引用

Journal of Environmental Sciences 2024年第2期136卷 237-247页

作者： Hua Tang Ying Wang Shengling Si Hongli Li david da Yong Chen National Institute of Metrology 18 BeisanhuandongluChaoyang DistrictBeijing 100029China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China Si Chuan Zhong Ce Biao Wu Technology Co.Ltd. Sichuan 610052China Department of Chemistry University of British ColumbiaVancouver V6T 1Z1BCCanada

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment *** effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of *** affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were *** optimum conditions were found to be 120℃,10 min,and 3 cycles,***-MS/MS method was developed to obtain the optimal sensitivity specific to *** method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/*** ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent *** optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target ***,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to *** is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.

关键词： Selective pressurized liquid extraction Liquid chromatography-mass spectrometry Perfluorinated compounds Atmospheric particulate matter Pollution control

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

Resource management at the network edge for federated learning

引用

Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade Luiz F.Bittencourt Nelson L.S.da Fonseca Institute of Computing State University of CampinasCampinasBrazil

Federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： Resource management Edge computing Federated learning Machine learning

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

Alt Isoenzymes Highly Expressed in Fatty Liver, Regulated by Wy-14643 and Free Fatty Acids Treatment, and Increases Glyceroneogenesis

Alt Isoenzymes Highly Expressed in Fatty Liver, Regulated by...

引用

作者： sa’ED ANEES saMOUR WORAIKAT 重庆医科大学

学位级别：硕士

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Sustainable electrosynthesis: Enantioselective electrochemical Rh(Ⅲ)/chiral carboxylic acid-catalyzed oxidative C–H cyclization coupled with hydrogen evolution reaction

引用

Chinese Chemical Letters 2024年第9期35卷 1-3页

作者： Xinghui Yao Zhouyu Wang da-Gang Yu Department of Chemistry Xihua UniversityChengdu 610039China Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengdu 610064China

Chiral compounds play a crucial role in the development of pharmaceuticals,pesticides,fragrances,and materials due to their unique stereochemical *** catalysis,which employs chiral catalysts to favor the production of one enantiomer over its mirror image,has emerged as a pivotal technique in the synthesis of chiral compounds[1].However,traditional asymmetric methods sometimes rely on environmentally harmful reducing or oxidizing agents,presenting a considerable challenge in the pursuit of green chemistry.

关键词： chiral oxidative catalyzed

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

The short and long-term effect of polystyrene nanoplastics on nitrifying sludge at high nitrite concentrations

引用

Journal of Environmental Sciences 2024年第1期135卷 222-231页

作者： Xiaolong Wang Jialu Huang Zhiqiang Qi Ruiqin Kang Chao Du da Li School of Chemical and Environmental Engineering Anyang Institute of TechnologyAnyang 455000China Henan Licheng Environmental Technology Co. Ltd.Anyang 455000China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

The effect of nanoplastics(NPs)on nitrite oxidation bacteria(NOB)community in treating high-strength wastewater remains unclear,which seriously affects the stability of nitrogen removal *** this study,highly active nitrifying sludge was enriched and exposed to 50nm polystyrene NPs(PS-NPs)for short-term(1,100,500,and 1000 mg/L,1.5 hr)and long-term(1,10,100 mg/L,40 days)at high nitrite *** contrast to previous studies,our results showed that the exposures to PS-NPs had little effect on nitrifying *** long-term exposure,the protein/polysaccharide ratios in extracellular polymeric substances(EPS)were positively correlated with PS-NPs concentrations(0.78–0.99).The produced reactive oxygen species(ROS)were gradually removed,and PS-NPs higher than 10 mg/L caused damage to membrane ***-term exposure for 40 days increased the community diversity and caused significant differences between the control and exposed *** control group were dominated by Nitrobacter and Exiguobacterium,while the exposure group was dominated by Bacillus,Mycobacterium,and Nitrospira.A noticeable shift in the NOB community from Nitrobacter(26.5%to 3.4%)to Nitrospira(1.61%to 14.27%)was observed.A KEGG analysis indicated a decrease in cell growth and death,cell motility and energy *** appeared that NOB could adapt to PS-NPs stress through enhanced secretion and removal of oxidative ***,this study provided new insights into the response mechanism of NOB to PS-NPs exposure.

关键词： Nanoplastics Nitrifying activity Extracellular polymeric substance(EPS) Exposure Community analysis

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

Could mammalian inorganic polyphosphate be a crucial signaling molecule in neurological disorders?

引用

Neural Regeneration Research 2024年第4期19卷 701-702页

作者： Renata Torres da Costa Maria E.Solesio Rutgers University Department of BiologyCamdenNJUSA

Since the early stages of life on earth,cellular metabolism has evolved to adapt to fluctuations in nutrient and oxygen *** this context,mammals,which are probably the organisms that show one of the highest levels of metabolic complexity,have developed an elegant system that uses constant and rechargeable energy sources of modulate their *** homeostasis is especially important in the central nervous system,as neurons and other cells in the brain are highly susceptible to fluctuations in nutrients and oxygen availability.

关键词： metabolism homeostasis neurological

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

Stabilisation of estuarine sediments with an alkali-activated cement for deep soil mixing applications

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1398-1410页

作者： Claver Pinheiro sara Rios António Viana da Fonseca Nuno Cristelo Centre of Physics of Minho and Porto Universities (CF-UM-UP) Azurém CampusUniversity of MinhoGuimarães4800-058Portugal CONSTRUCT-GEO Faculty of EngineeringUniversity of PortoRua Dr.Roberto FriasPortos/n 4200-465Portugal CQ-VR School of Science and TechnologyUniversity of Trás-os-Montes e Alto DouroVila Real5000-801Portugal

In this work,an alternative alkali-activated cement(AAC)made of ladle slag precursor mixed with sodium hydroxide and sodium silicate has been developed to enhance the bearing capacity of estuarine soils in coastal conditions via deep soil mixing(DSM).The AAC was optimized to use a low reactivity precursor(ladle slag)and to deal with a contaminated high-water content natural sediment cured under *** material performance was analysed by comparison to a mixture made with Portland cement and cured in the same *** and unconfined compressive strength tests as well as seismic waves measurements after 3-,7-,14-and 28-d curing were performed to obtain a relationship between elastic stiffness and strength with curing time for both ***,the AAC mix demonstrated superior strength results,exhibiting almost double flexural and compressive strengths after 28 d compared to the Portland cement *** AAC mix also showed a higher rate of stiffness increase than the Portland cement mix,which has a higher initial stiffness at young ages but lower stiffness *** analysis confirmed that the proposed AAC could effectively immobilise any contaminants from soil or *** effect of curing under stress was analysed in triaxial compression tests and found to be insignificant,indicating that laboratory data obtained without stress curing can represent the material's behaviour in a DSM column,which will cure under the weight of the column.

关键词： Alkaline-activation Steel slag Submerged curing Seismic wave measurements Leachate analysis Curing under stress

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

Attaining synergetic equilibrium of electrical conductivity and tensile strength in GQDs@GN/Cu composites through multi-scale intragranular and intergranular reinforcements

引用

Rare Metals 2024年第1期43卷 366-379页

作者： Shuang-Yin Zhang Liang Liu Rui Bao Jian-Hong Yi Sheng-da Guo Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and TechnologyKunming 650093China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China

The configuration and quality of reinforcements, as well as the robustness of interfacial bonding,holding a critical significance in determining the concurrence between electrical conductivity and mechanical strength in metal matrix composites. In this study, citric acid was employed as the precursor for synthesizing multiscale carbon nanomaterials(graphene quantum dots and graphene, abbreviated as GQDs and GN). The GQDs@GN/Cu composites were fabricated through a segmented ball milling process in conjunction with subsequent spark plasma sintering(SPS). The intragranular GQDs and intergranular GQDs@GN had synergistically reinforced Cu composites through Orowan strengthening, load transfer strengthening and refinement strengthening. Furthermore,the robust interface bonding between GQDs@GN and Cu effectively mitigated interfacial impedance stemming from electron-boundary scattering. The yield strength and ultimate tensile strength of the GQDs@GN/Cu composites were recorded as 270 and 314 MPa, respectively, representing an improvement of 92 and 28% over pure Cu, while maintaining electrical conductivity at a level comparable to that of pure Cu. This study advances the understanding of the possibility of realizing a synergistic compatibility between electrical conductivity and mechanical strength in Cu composites.

关键词： Cu matrix composites Interface bonding Mechanical property Graphene quantum dots(GQDs) Electrical conductivity

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

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：