检索结果-南通市图书馆

Allophane as a Nanotechnological Additive in Masonry Materials to Increase Resistance and Waterproofing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Materials Physics and Chemistry 2024年第8期14卷 196-212页

作者： Edward H. Jiménez Joao Rivera Juan H. Villalba Paola E. Vera Marlon Cuenca Belén Granja javier Fuentes Sandra Gavilanes Daniel Hidalgo Fernando garcia Jose Bermudez Washington Ruiz Alexis Martial Debut Facultad de Ingeniera Qumica Universidad Central del Ecuador Quito Ecuador Facultad de Arquitectura y Urbanismo Universidad Central del Ecuador Quito Ecuador Nanomaterials Characterization Laboratory Universidad de las Fuerzas Armadas ESPE Sangolqu Ecuador

The constant need for high-strength materials in the construction industry promotes the research of additives that improve the properties of masonry materials. The use of allophane as an additive in concrete and mortar mixtures was implemented to improve their strength and waterproofing, respectively, using compression and water absorption tests according to their corresponding standards (ASTM C1231, ASTM D2938, and ASTM C1585). The samples were evaluated at different concentrations and curing ages. In addition, different sand/cement ratios were considered for the mortar. The results revealed that there was a 9.4% increase in compressive strength in concrete and a 23.7% reduction in water absorption in mortar for the 5:1 ratio. These changes would be the result of the interaction of the nanoporous additive in the atomic crystal structure of the material demonstrating the nanotechnological nature of allophane.

关键词： Allophane Nano Additive Strength Impermeability Concrete Mortar

Lie Symmetries of Quasihomogeneous Polynomial Planar Vector Fields and Certain Perturbations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2005年第1期21卷 185-192页

作者： javier CHAVARRIGA Isaac A.garcia Departament de Matemdtica Universitat de LleidaAvda.Jaume II6925001LleidaSpain

In this work we study Lie symmetries of planar quasihomogeneous polynomialvector fields from different points of view, showing its integrability. Additionally, we show thatcertain perturbations of such vector fields w... 详细信息

关键词： Lie symmetries Quasi-homogeneous systems Planar vector fields

Human condition monitoring in hazardous locations using pervasive RFID sensor tags and energy-efficient wireless networks

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第9期13卷 674-688页

作者： javier G.ESCRIBANO Andrés garcia Autolog Group Industrial Engineering SchoolUniversity of Castilla-La ManchaAvda.Camilo José Cela s/n13071 Ciudad RealSpain

Tracking persons in dangerous situations as well as monitoring their physical condition, is often crucial for their safety. The systems commonly used for this purpose do not include individual monitoring or are too expensive and intrusive to be deployed in common situations. In this project, a mobile system based on energy-efficient wireless sensor networks (WSNs) and active radio frequency identification (RFID) has been developed to achieve ubiquitous positioning and monitoring of people in hazardous situations. The system designed can identify each individual, locate him/her, send data regarding their physical situation, and ascertain whether they are located in a confined space. A new algorithm called time division double beacon scheduling (TDDBS) has been implemented to increase operation time and data transmission rate of the nodes in the system. The results show that the use of this system allows us to find the location and state of a person, as well as to provide an analysis of the potential risks at each moment, in real time and in an energy-efficient way. In an emergency, the system also allows for quicker intervention, as it not only provides the location and causes of the event, but also informs about the physical condition of the individual at that moment.

关键词： Active RFID Wireless sensor networks (WSNs) ZigBee Human monitoring Time division double beacon sched-uling (TDDBS)

在线全文

学校读者我要写书评

暂无评论

等离激元材料

环球科学 2018年第12期 32-33页

作者：哈维尔·加西亚·马丁内斯(撰文) 谢汝雨(翻译) 不详

2007年,加州理工学院的哈里·阿特沃特(Harry Atwater)在《科学美国人》上撰文预测:“等离激元光子学”(plasmonics)技术最终会通向从高灵敏度的生物探测器到隐形斗篷的一系列应用。10年后,多种等离子体技术已经实现了商业化,而另一些... 详细信息

2007年,加州理工学院的哈里·阿特沃特(Harry Atwater)在《科学美国人》上撰文预测:“等离激元光子学”(plasmonics)技术最终会通向从高灵敏度的生物探测器到隐形斗篷的一系列应用。10年后,多种等离子体技术已经实现了商业化,而另一些技术正由实验室走向市场。这些技术都依赖于控制电磁场和金属(通常是金或银)中自由电子之间的相互作用。

关键词：等离子体技术《科学美国人》材料加州理工学院相互作用自由电子探测器灵敏度

Thermo-electro-mechanical microstructural interdependences in conductive thermoplastics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2023年第1期9卷 955-965页

作者： javier Crespo-Miguel Sergio Lucarini Angel Arias Daniel garcia-Gonzalez Department of Continuum Mechanics and Structural Analysis Universidad Carlos III de MadridAvda.de la Universidad 3028911 LeganésMadridSpain Department of Civil and Environmental Engineering Imperial College of LondonSouth Kensington CampusLondon SW72AZUK

Additive manufacturing has enabled the design of thermoplastic components that provide structural support,electrical conductivity and heat generation modulated by mechanical *** mechanisms and interplays that govern the material response at the microstructural level remain,however,***,we develop an experimental method to characterise conductive filaments from a combined mechanical,electrical and thermal *** approach is used to unravel exciting material interplays of conductive polylactic *** overcome experimental limitations that prevent a complete microstructural analysis of the problem,we develop a full-field homogenisation framework and implement it for finite *** framework accounts for viscoplasticity,electrical and thermal conduction,convection and heat generation via Joule effect,as well as for the interdependences between *** experimental validation,the framework is applied to virtually optimise fabrication requirements to obtain desired properties in final products,i.e.,stiffer products,filaments with higher conductivities or with better sensing capabilities.

关键词： conductive electrical overcome

Li2SnO3 branched nano- and microstructures with intense and broadband white-light emission

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第2期12卷 441-448页

作者： Miguel garcia-Tecedor javier Bartolome David Maestre Achim Trampert Ana Cremades Dpt. Fisica de Materials Facultad de CC. Fisicas Universidad Complutense de Madrid Madrid 28040 Spain Paul-Drude-Institut fur Festkorperelektronik Hausvogteiplatz 5-7 Berlin 10117 Germany Institute of Advanced Materials (INAM) Universitat Jaume I Castello 12006 Spain Dpt. Fisica de Materiales Facultad de CC. Ftsicas Universidad Complutense de Madrid Madrid 28040 Spain

Exploiting the synergy between microstructure, morphology and dimensions by suitable nanomaterial engineeri ng, can effectively upgrade the physical properties and material performances. Li2SnO3 elongated nano- and microstructures in form of belts, wires, rods and branched structures have been fabricated by a vapor-solid method at temperatures ranging from 700 to 900℃ using metallic Sn and Li2CO3 as precursors. The achievement of these new morphologies can face challenging applications for Li2SnO3, not only in the field of energy storage, but also as building blocks in optoelectronic devices. The micro? and nanostructures grown at 700 and 800℃ correspond to monoclinic Li2SnO3, while at 900℃ complex Li2S nO/SnO2 core-shell microstructures are grow n, as con firmed by X-ray diffractio n and Rama n spectroscopy. Transmission electron microscopy reveals structural disorder related to stacking faults in some of the branched structures, which is associated with the prese nee of the low-temperature phase of L12S nO3. The luminescent resp onse of these structures is domi nated by in tense emissi ons at 2, 2.5 and 3 eV, almost completely covering the whole range of the visible light spectrum. As a result, white-light emission is obtained without the need of phosphors or complex quantum well heterostructures. Enhanced functionality in applications such as in light-emitting devices could be exploited based on the high luminescenee intensity observed in some of the analysed Li2SnO3 structures.

关键词： lithium oxides white light emitters nanostructures luminescenee

Use of a lyophilized bovine pericardium graft to repair tunical defect in patients with Peyronie＇s disease： experience in a clinical setting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2017年第3期19卷 316-320页

作者： javier Romero Otero Borja garcia Gomez Jose Medina Polo Carlos Pascual Mateoe Silvia garcia Barreras Eduard garcia Cruz javier de la Riva de la Vifia Alfredo Rodriguez Antolin 12 de Octubre University Hospital Department of Urology Madrid Spain Monteprincipe University Hospital Department of Urology Madrid Spain Clinic Hospital Department of Urology Barcelona Spain

Many different materials are available for grafting during surgery for Peyronie＇s disease （PD）. To study the outcomes associated with the use of a lyophilized bovine pericardium graft （Peri-Guard） to repair tunical defects in patients with PD, descriptive study of 43 patients with disabling penile curvature was performed. Curvature was measured before and after the intervention using a standardized procedure. Surgical technique was plaque excision and grafting of the tunical defect carried out by a single surgeon. A lyophilized bovine pericardium patch was used for grafting. We measured the change in penile curvature and length, the ability to perform successful sexual intercourse without further pharmacological or surgical treatment, and the satisfaction with treatment. Follow-up data were available for a total of 41 patients. Median age was 50 years （IQR 48-52）; mean follow-up time was 14 ± 6 months. Complete penile straightening was achieved in 33 patients （80.5%） and five patients （12.2%） had curvature under 20. Three months after surgery and stretching therapy, mean （s.d.） flaccid penile length increased from 11.2 ± 2.8 cm to 12.1 ± 2.9 cm （P = 0.062）. Seventy-five percentage of patients reported being able to achieve successful intercourse without further treatment. Eighty-five percentage of patients reported to be satisfied with the treatment. There was no evidence of tissue rejection or infection, and only four patients suffered an adverse event. Plaque excision and grafting of the tunical defect with lyophilized bovine pericardium seems to be a safe and effective treatment for patients with PD.

关键词： penile curvature pericardium patch Peyronie's disease surgical treatment

TangiWheel: A Widget for Manipulating Collections on Tabletop Displays Supporting Hybrid Input Modality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2012年第4期27卷 811-829页

作者： Alejandro Catalá Fernando garcia-Sanjuan javier Jaen Jose A.Mocholi Software Engineering and Information Systems Research Group Department of Information Systems and Computation Universitat Politècnica de ValènciaCamí de Vera s/n46022ValenciaSpain ACM IEEE

In this paper we present TangiWheel, a collection manipulation widget for tabletop displays. Our implementation is flexible, allowing either multi-touch or interaction, or even a hybrid scheme to better suit user choice and convenience. Different TangiWheel aspects and features are compared with other existing widgets for collection manipulation. The study reveals that TangiWheel is the first proposal to support a hybrid input modality with large resemblance levels between touch and tangible interaction styles. Several experiments were conducted to evaluate the techniques used in each input scheme for a better understanding of tangible surface interfaces in complex tasks performed by a single user （e.g., involving a typical master-slave exploration pattern）. The results show that tangibles perform significantly better than fingers, despite dealing with a greater number of interactions, in situations that require a large number of acquisitions and basic manipulation tasks such as establishing location and orientation. However, when users have to perform multiple exploration and selection operations that do not require previous basic manipulation tasks, for instance when collections are fixed in the interface layout, touch input is significantly better in terms of required time and number of actions. Finally, when a more elastic collection layout or more complex additional insertion or displacement operations are needed, the hybrid and tangible approaches clearly outperform finger-based interactions.

关键词： interactive surface multi-touch tangible user interface tabletop display experimentation

Emerging patterns in the construction of Sejima’s,Sanaa’s and Nishizawa’s domestic spaces,from 1987 to 2010

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2022年第3期11卷 375-401页

作者： Pedro garcia Martinez Francisco javier Maroto Ramos Universidad Politecnica de Cartagena Escuela Tecnica Superior de Arquitectura y Tecnologfa de EdificationCartagena30201Spain Universidad Politecnica de Madrid Escuela Tecnica Superior de Arquitectura de MadridMadrid28040Spain

Sejima and Nishizawa have developed their work without explicitly referencing a theoretical ***,they have stated that their housing projects describe their"architectural biography."This study presents the hypothesis that systermic theories had infu-enced their housing projects at a spatial and constructive *** the aim of testing it,the research produces four lines of ***,we observe that the word system is prominently current in a signifcant sample of their published *** describe how architects like Tomi-naga,Ito,Taki,and Shinohara,who infuenced Sejima when she was still a student,discussed this concept inspired by Christopher Alexander's *** second line brings together all the couple's single-family housing projects published between 1987 and 2010 for the first time in a single document,as well as an original graphic-constructive reconstruction of the most outstanding ***,we unveil the emergence of four constructive patterns by applying these theories to the graphic material ***,we summarize the results in dia-grams,showing the frequency,intensity,and continuity of the identified patterns in the four phases throughout the studied *** the hypothesis facilitates further research relate their domestic work and their other types of projects.

关键词： Architecture House Pattern Sejima Nishizawa SANAA