检索结果-南通市图书馆

Fabrication of Superhydrophobic Surfaces on Aluminum Alloy Via Electrodeposition of Copper Followed by Electrochemical Modification

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2011年第3期3卷 160-165页

作者： Ying Huang d.K.Sarkar X-grant Chen University Research Center on Aluminum (CURAL) University of Qubec at Chicoutimi

Superhydrophobic aluminum surfaces have been prepared by means of electrodeposition of copper on aluminum surfaces, followed by electrochemical modification using stearic acid organic molecules. Scanning electron microscopy(SEM) images show that the electrodeposited copper films follow "island growth mode" in the form of microdots and their number densities increase with the rise of the negative deposition potentials. At an electrodeposition potential of-0.2 V the number density of the copper microdots are found to be 4.5×104cm^(-2)that are increased to 2.9×105cm^(-2)at a potential of-0.8 V. Systematically, the distances between the microdots are found to be reduced from 26.6 μm to 11.03 μm with the increase of negative electrochemical potential from-0.2 V to-0.8 V. X-ray diffraction(XRd) analyses have confirmed the formation of copper stearate on the stearic acid modified copper films. The roughness of the stearic acid modified electrodeposited copper films is found to increase with the increase in the density of the copper microdots. A critical copper deposition potential of-0.6 V in conjunction with the stearic acid modification provides a surface roughness of 6.2 μm with a water contact angle of 157?, resulting in superhydrophobic properties on the aluminum substrates.

关键词： Superhydrophobic aluminum surface Water contact angle Copper microdots Surface roughness Electrochemical modification

Emerging carbon-based nanosensor devices:structures,functions and applications

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2015年第1期3卷 63-72页

作者： S.Manzetti d.Vasilache F.Enrichi Fjordforsk A.S. Institute for Science and Technology6894 VangsnesNorway Science of Life Laboratory Department of Cell and Molecular BiologyUppsala University75124 UppsalaSweden Laboratory of Micromachined Structures Microwave Circuits and Devices-L4National Institute for Research and Development in Microtechnologies(IMT Bucharest)023573 BucharestRomania Laboratory for Nanofabrication of Nanodevices Veneto NanotechCorso Stati Uniti 435127 PadovaItaly

Bionanosensors and nanosensors have been devised in recent years with the use of various materials including carbon-based nanomaterials, for applications in diagnostics, environmental science and microelectronics. Carbon-based materials are critical for sensing applications, as they have physical and electronic properties which facilitate the detection of substances in solutions, gaseous compounds and pollutants through their conductive prop- erties and resonance-frequency transmission capacities. In this review, a series of recent studies of carbon nanotubes （CNTs） based nanosensors and optical systems are repor- ted, with emphasis on biochemical, chemical and envi- ronmental detection. This study also encompasses a background and description of the various properties of the nanomaterials, and the operation mechanism of the man- ufactured nanosensors. The use of computational chemistry is applied in describing the electronic properties and molecular events of the included nanomaterials during operation. This review shows that resonance-based sensing technologies reach detection limits for gases, such as ammonia down to 10-24 level. The study also shows that the properties of the carbon nanomaterials give them unique features that are critical for designing new sensors based on electrocatalysis and other reactive detection mechanisms. Several research fields can benefit from the described emerging technologies, such as areas of research in environmental monitoring, rapid-on site diagnostics, in situ analyses, and blood and urine sampling in medical and sport industry. Carbon nanomaterials are critical for the operational sensitivity of nanosensors. Considering the low cost of fabrication, carbon nanomaterials can represent an essential step in the manufacturing of tomorrow＇s commercial sensors.

关键词： Nanomaterials.Carbon-based.graphene .Nanotubes. Sensors.detectors - Quantum mechanics

Quality assessment and hydrogeochemical characteristics of groundwater in Agastheeswaram taluk, Kanyakumari district, Tamil Nadu, India

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of geochemistry 2014年第3期33卷 221-235页

作者： Srinivas Y Hudson Oliver d Stanley Raj A Chandrasekar N Centre for geoTechnology Manonmaniam Sundaranar University Vel Tech dr. RR & dr. SR Technical University Avadi Chennai

The present study investigates the hydrogeochemical characteristics of groundwater quality in Agastheeswaram taluk of Kanyakumari district, Tamil Nadu, India. A total of 69 groundwater samples were collected during pre- and post-monsoon periods of 2011–2012. The groundwater quality assessment has been carried out by evaluating the physicochemical parameters such as pH, EC, TdS, HCO3-, Cl-, SO42-, Ca2+, Mg2+, Na+ and K+ for both the seasons. Based on these parameters, groundwater has been assessed in favor of its suitability for drinking and irrigation purpose. dominant cations for both the seasons are in the order of Na+ > Ca2+ > Mg2+ > K+ while the dominant anions for post monsoon and pre monsoon have the trends of Cl- > HCO3- > SO42- and HCO3- > Cl- > SO42-, respectively. Analytical results observed from various indices reveal that the groundwater quality is fairly good in some places. Analytical results of few samples show that they are severely polluted and incidentally found to be near the coasts, estuaries and salt pans in the study area. The gibbs plot indicates that the majority of groundwater samples fall in rock dominant region, which indicates rock water interaction in the study area. The United States salinity(USSL) diagram shows that the groundwater is free from sodium hazards but the salinity hazard varies from low to very high throughout the study area. This reveals that the groundwater is moderately suitable for agricultural activities. The observed chemical variations in pre-monsoon and post-monsoon seasons may be the effect to rock-water interactions, ion-exchange reactions, and runoff of fertilizers from the surrounding agricultural lands.

关键词：地下水质量评价地下水水质水文特性马里印度水岩相互作用物理化学参数研究区域

Pathophysiology of increased intestinal permeability in obstructive jaundice

在线全文

学校读者我要写书评

暂无评论

World Journal of gastroenterology 2007年第48期13卷 6458-6464页

作者： Stelios F Assimakopoulos Chrisoula d Scopa Constantine E Vagianos department of Internal Medicine School of Medicine University of Patras department of Pathology School of Medicine University of Patras 1~(st) Surgical department "Saint Panteleimon" General Hospital of Nikaia

despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal dysfunction. The key event in the pathophysiology of obstructive jaundice-associated complications is endotoxemia of gut origin because of intestinal barrier failure. This breakage of the gut barrier in obstructive jaundice is multi-factorial, involving disruption of the immunologic, biological and mechanical barrier. Experimental and clinical studies have shown that obstructive jaundice results in increased intestinal permeability. The mechanisms implicated in this phenomenon remain unresolved, but growing research interest during the last decade has shed light in our knowledge in the field. This review summarizes the current concepts in the pathophysiology of obstructive jaundice-induced gut barrier dysfunction, analyzing pivotal factors, such as altered intestinal tight junctions expression, oxidative stress and imbalance of enterocyte proliferation and apoptosis. Clinicians handling patients with obstructive jaundice should not neglect protecting the intestinal barrier function before, during and after intervention for the relief of this condition, which may improve their patients’ outcome.

关键词： Obstructive jaundice Intestinal barrier Intestinal permeability Endotoxemia Bacterial translocation Tight junctions Occludin Claudin-4 Apoptosis Oxidative stress

Evaluation of alternative conceptual models for groundwater modelling

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

geoscience Frontiers 2017年第3期8卷 437-443页

作者： Yangxiao Zhou H.M.P.S.d.Herath UNESCO-IHE Institute for Water Education

This study evaluates the alternative conceptual models for groundwater modelling. A true model was created with a synthetic alluvial fan-plain hydrogeological framework. Various alternative conceptual models were evaluated for groundwater flow simulations. The first alternative model is a single aquifer layer model; the second alternative model is a 3-layer aquifer model; and the third model is a B-layer model consisting of 3 aquifers separated by 2 aquitards. All models could fit very well to the observa- tions with optimized values of hydraulic conductivities. However, the single aquifer layer model can only compute water balance components with good accuracy. The 3-layer aquifer model can be used for water balance computation and groundwater head simulation with small errors. The 5-layer model is capable of simulating water budget, groundwater head distribution and travel times with high accuracy. Multi- model analysis found only the 3rd alternative model superior.

关键词： Alternative conceptual modelsMulti-model analysisWater budgetTravel time

Effect of irregularity on the propagation of torsional surface waves in an initially stressed anisotropic poro-elastic layer

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2010年第4期31卷 481-492页

作者： S.gUPTA A.CHATTOPAdHYAY d.K.MAJHI department of Applied Mathematics Indian School of Mines University

The paper studies the propagation of torsional surface waves in an initially stressed anisotropic poro-elastic layer over a semi-infinite heterogeneous half space with linearly varying rigidity and density due to irregularity at the interface. The irregularity is taken in the half space in the form of a rectangle. It is observed that torsional surface waves propagate in this assumed medium. In the absence of the irregularity, the velocity equation of the torsional surface wave is also obtained. For a layer over a homogeneous half space, the velocity of torsional surface waves coincides with that of the Love waves.

关键词： irregularity torsional surface waves anisotropic initial stress

groundwater Origin and Its Hydrogeochemistry through gIS Maps in Linares Region, Mexico

在线全文

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2013年第8期5卷 1-12页

作者： René Alberto dávila Pórcel Héctor de León-gómez Instituto de Ingeniería Civil (IIC) Facultad de Ingeniería Civil (FIC) Universidad Autónoma de Nuevo León (UANL) Monterrey México

The North-East region of Mexican Republic has a semi-arid weather condition;this area covers partially Tamaulipas, Nuevo León and Coahuila states. Pablillo River Basin (PRB) is located close to Nuevo León south border and its catchment area involves Linares City (LC), Hualahuises City (HC) and Cerro-Prieto dam (CP). This reservoir captures drinking water to Monterrey Metropolitan Zone (MMZ) the major urban center on the north-east Mexican region. More than 50% of the potable water for LC comes from groundwater stockpiles. A combination of gIS maps and major ion chemistry analysis has been assessed, to know the origin, geochemical evolution, and hydraulic interconnection of groundwater. during 2008-2009, 46 groundwater samples were taken and analyzed around LC and HC. gIS technology was use to analyze the spatial distribution of the constituents of groundwater through thematic maps. The major ion analysis and its results suggest the presences of two aquifers;shallow porous aquifer on the top and fractured aquifer on the bottom. general water mineralization was discovered, including dissolution of halite, dolomites and carbonates through the aquifers. Water quality varies widely through the aquifers, and the general pathways go from southwest to northeast direction. The overexploitation of groundwater increases the water mixing of groundwater between shallow and deeper aquifers. Natural origin of groundwater and groundwater pollution by anthropogenic activities should be considered in the groundwater quality analysis for drinking water purpose.

关键词： groundwater Hydrogeochemistry gIS Mexico

Construction of high-pressure adsorption isotherm:A tool for predicting coalbed methane recovery from Jharia coalfield,India

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

International Journal of Mining Science and Technology 2019年第5期29卷 765-769页

作者： Mohammad Asif d.C.Panigrahi Paul Naveen Keka Ojha department of Mining Engineering Indian Institute of Technology(ISM)Dhanbad 826004India department of Petroleum Engineering Indian Institute of Technology(ISM)Dhanbad 826004India

Adsorption isotherm relates the gas storage capacity as a function of pressure at constant *** this paper,adsorption isotherm of two dry borehole samples was constructed in the laboratory using the manometric *** was measured for two gases,i.e.,CH4 and CO2 to pressure up to 8.4 *** the construction of sorption isotherm,coal was characterized by proximate,ultimate and petrographic *** gas content of these two samples was found 2.29 m3/t and 2.75 m3/*** images were obtained for the pore size distribution of coal using pore image *** of coalbed methane recovery from CH4 adsorption isotherm showed that these coalbeds are under ***2 isotherm was constructed to estimate enhanced coalbed methane(ECBM)*** wise CO2/CH4 sorption ratio was found 2.09 times to 2.75 times *** paper presents the interpretation of isotherm data to find the recovery factor of methane production from Jharia coalfield.

关键词： Coalbed methane Adsorption isotherm Pore image analysis gas content Jharia coalfield

Multiscale Nanorod Metamaterials and Realizable Permittivity Tensors

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2012年第2期11卷 489-507页

作者： g.Bouchitte C.Boure IMATH University of Sud-Toulon-Var83957 La Garde cedexFrance.

Our aim is to evidence new 3d composite diffractive structures whose effective permittivity tensor can exhibit very large positive or negative real *** use a reiterated homogenization procedure in which the first step consists in considering a bounded obstacle made of periodically disposed parallel high conducting metallic fibers of finite length and very thin cross *** shown in[2],the resulting constitutive law is *** by reproducing periodically the same kind of obstacle at small scale,we obtain a local effective law described by a permittivity tensor that we make explicit as a function of the *** to internal resonances,the eigenvalues of this tensor have real part that change of sign and are possibly very large within some range of *** simulations are shown.

关键词： Homogenization photonic crystals metamaterials micro-resonators effective tensors non local effects