检索结果-南通市图书馆

Triboelectric nanogenerator based on electrodeposited Ag octahedral nano-assemblies

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2023年第8期83卷 478-495,I0012页

作者： M.Edith Navarro-Segura Margarita Sanchez-Dominguez Ana Arizmendi-Morquecho j.alvarez-Quintana Group of Colloidal and Interfacial Chemistry Applied to Nanomaterials and Nanoformulations Centro de Investigacion en Materiales Avanzados S.C Unidad MonterreyAlianza Norte#202Autopista Monterrey-Aeropuerto Km.10.C.P.66628 ApodacaNuevo LeonMexico GENES-Group of Embedded Nanomaterials for Energy Scavenging Centro de Investigacion en Materiales Avanzados S.C.Unidad MonterreyAlianza Norte#202Autopista Monterrey-Aeropuerto Km.10.C.P.66628 ApodacaNuevo LeonMexico

The tremendous potential of triboelectric generators-TENGs for converting mechanical energy into electrical energy places them as one of the most promising energy harvesting technologies. In this work, the fabrication of enhanced performance TENGs using Ag octahedron nano-assemblies on ITO as electrodes significantly increases the electric charge collection of the induced tribocharges. Thereby, nanostructured electrical contacts coated with Ag macroscale nano-assemblies with octahedral features were obtained by the electrodeposition technique on flexible PET/ITO substrates. Consequently, the nanostructured triboelectric generator-TENG exhibited 65 times more maximum output power, and almost 10 times more open circuit output voltage than that of a TENG with non-nanostructured contacts passing from μW to m W capabilities, which was attributed to the increment of intrinsic interface states due to a higher effective contact area in the former. Likewise, output performances of TENGs also displayed an asymptotic behavior on the output voltage as the operating frequency of the mechanical oscillations increased, which is attributed to a decrement in the internal impedance of the device with frequency. Furthermore, it is shown that the resulting electrical output power can successfully drive low power consumption electronic devices. On that account, the present research establishes a promising platform which contributes in an original way to the development of the TENGs technology.

关键词： Triboelectric generator Nanostructured electrodeposited electrodes Ag octahedral nanoassemblies Electrode surface structure

Merits and limitations of TiO2-based photocatalytic pretreatment of soils impacted by crude oil for expediting bioremediation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2017年第3期11卷 387-394页

作者： Yu Yang Hassan javed Danning Zhang Deyi Li Roopa Kamath Kevin McVey Kanwartej Sra Pedro j.j. alvarez Department of Civil and Environmental Engineering Rice University Houston TX 77005 USA Department of Chemistry Rice University Houston TX 77005 USA Department of Civil and Environmental Engineering Tongji University Shanghai 200092 China Chevron Energy Technology Company Houston TX 77002 USA

Heavy hydrocarbons （HHCs） in soils impacted by crude oil spills are generally recalcitrant to biodegrada- tion due to their low bioavailability and complex chemical structure. In this study, soils were pretreated with varying concentrations of ultraviolet radiation A （UVA） or ultraviolet radiation C （UVC） activated titanium dioxide （TiO2）（1%-5%） under varying moisture conditions （0%- 300% water holding capacity （WHC）） to enhance biodegradation of HCCs and shorten remediation time- frames. We demonstrate that pretreatment of impacted soils with UVC-activated TiO2 in soil slurries could enhance bioremediation of HHCs. Total petroleum hydrocarbon （TPH） removal after 24 h exposure to UVC （254 nm and 4.8 mW/cm2） was （19.15：1.6）% in slurries with 300% WHC and 5 wt-% TiO2. TPH removal was non-selective in the C15-C36 range and increased with moisture content and TiO2 concentration. In a 10-d bioremediation test, TPH removal in treated soil increased to （26.05：0.9）%, compared to （15.45：0.8）% for controls without photo- catalytic pre-treatment. Enhanced biodegradation was also confirmed by respirometry. This suggests that addition of UVC-activated TiO2 to soil slurries can transform recalcitrant hydrocarbons into more bioavailable and biodegradable byproducts and increase the rate of subsequent biodegradation. However, similar results were not observed for soils pretreated with UVA activated TiO2. This suggests that activation of TiO2 by sunlight and direct addition of TiO2 to unsaturated soils within landfarming setting may not be a feasible approach. Nevertheless, less than 1% of UVA （7.5 mW/cm2） or UVC （1.4 mW/cm2） penetrated beyond 0.3 cm soil depth, indicating that limited light penetration through soil would hinder the ability of TiO2 to enhance soil bioremediation under land farming conditions.

关键词： ZiO2 pretreatment bioremediation total petroleum hydrocarbons ultraviolet

Rotorcraft with a 3DOF Rigid Manipulator:Quaternion-based Modeling and Real-time Control Tolerant to Multi-body Couplings

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 Automation and computing 2018年第5期15卷 547-558页

作者： j.alvarez-Munoz N.Marchand j.F.Guerrero-Castellanos j.j.Tellez-Guzman j.Escareno M.Rakotondrabe Polytechnic Institute of Advanced Sciences FR 94200 ParisFrance Univ.Grenoble Alpes GIPSA-LabFR-38000 GrenobleFrance Autonomous University of Puebla(BUAP) Faculty of ElectronicsMX 72570 PueblaMexico University of Limoges ENSIL-ENSCI XLIM Laboratory UMR CNRS 7252Parc Ester Technopole16 rue AtlantisLimoges 87068France FEMTO-ST Institute UMR CNRS-UFC/ENSMM/UTBMAutomatic Control and Micro-Mechatronic DepartmentFR BesanconFrance

This paper proposes a simple solution for the stabilization of a mini-quadcopter carrying a 3DoF（degrees of freedom） manipulator robot in order to enhance its achievable workspace and application profile. Since the motion of the arm induces torques which degrade the stability of the system, in the present work, we consider the stabilization of both subsystems： the quadcopter and the robotic arm. The mathematical model of the system is based on quaternions. Likewise, an attitude control law consisting of a bounded quaternion-based feedback stabilizes the quadcopter to a desired attitude while the arm is evolving. The next stage is the translational dynamics which is simplified for control（nonlinear） design purposes. The aforementioned controllers are based on saturation functions whose stability is explicitly proved in the Lyapunov sense. Finally, experimental results and a statistical study validate the proposed control strategy.

关键词： Observer-based control quaternion and Newton-Euler modeling bounded-input control aerial manipulator disturbancerejection.

Schottky photodiode using submicron thick diamond epilayer for flame sensing

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2009年第1期1卷 30-33页

作者： Y.Koide M.Y.Liao j.alvarez M.Imura K.Sueishi F.Yoshifusa Sensor Materials Center (SenMC) National Institute for Materials Science (NIMS) Laboratoire de Génie Electrique de Paris (UMR 8507 CNRS) Ecole Supérieure d’Electricité Universités Paris VI et Paris XI International Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS) ANTEC Co.

The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor with a wide-bandgap of 5.5 e V, exhibiting an intrinsic solar-blindness for deep-ultraviolet(DUV) detection. In this work, by using a submicron thick boron-doped diamond epilayer grown on a type-Ib diamond substrate, a Schottky photodiode device structure- based flame sensor is demonstrated. The photodiode exhibits extremely low dark current in both forward and reverse modes due to the holes depletion in the epilayer. The photodiode has a photoconductivity gain larger than 100 and a threshold wavelength of 330 nm in the forward bias mode. CO and OH emission bands with wavelengths shorter than 330 nm in a flame light are detected at a forward voltage of-10 V. An alcohol lamp flame in the distance of 250 mm is directly detected without a focusing lens of flame light.

关键词： Flame sensing Boron-doped diamond Schottky photodiode

Unintended Consequences of Silver Nanoparticle Releases: Mechanistic Insights from Microbiology

在线全文

学校读者我要写书评

暂无评论

Unintended Consequences of Silver Nanoparticle Releases: Mec...

A Three-Dimensional Range-Free Localization Algorithm Based on Mobile Beacons for Wireless Sensor Networks

全国环境纳米技术及生物效应学术研讨会

作者： Pedro j.j.alvarez Dept.of Civil ＆ Environmental Engineering Rice University

As a broad-spectrum antimicrobial agent, silver nanoparticles（AgNPs） are by far the most widely commercialized nanomaterial;about one-quarter of about 1500 nanotechnology-enhanced commercial products contain AgNPs. Thus, it is important to consider the unintended consequences of accidental and incidental releases of AgNPs to the environment and to sewage treatment plants. This presentation will address how AgNPs may affect ecosystem productivity and critical microbial ecosystem services, including biological treatment processes. We will also discern whether AgNPs exert direct "particle-specific" effects beyond the known antimicrobial activity of released silver ions（Ag+）, which is critical to understand how water chemistry affects nanoparticle bioavailability, reactivity and toxicity. Differential effects of AgNPs on bacterial gene expression and activities associated with the nitrogen cycle will also be discussed in the context of water quality. Counterintuitive effects of sub-lethal exposure to AgNPs on microbial viability and biofilm formation will also be presented. Finally, the results will be integrated to infer on how to steward safer and eco-responsible nanotechnology.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Computer Aided Drafting,Design and Manufacturing 2010年第1期20卷 83-92页

作者： GUERRERO E alvarez j RIVERO L School of Electronics and Information Engineering Beijing University of Aeronautics and Astronautics

In wireless sensor networks （WSNs） the position information of individual nodes is a matter of vital importance because allows the implementation of necessary network functions such as routing, querying and other applications. The objective of this paper is to propose an algorithm of three-dimensional distributed range-free localization for WSNs, using a mobile beacon （MB） equipped with a rotary and tilting directional antenna. This algorithm, denominated as the three-dimensional azimuthally defined area localization algorithm （3D- ADAL）, is executed in each sensor node and is based only on the analysis of the information received from the MB, therefore is energy efficient and contributes to extend the lifetime of the sensor network. Additionally the proposed algorithm has the advantage of being simple and economical. The simulation results show that the proposed algorithm is a practical, effective and accurate method for a three-dimensional location of sensor nodes in a WSN.

关键词： 3D localization wireless sensor network mobile beacon directional antenna

Redundancy Ring Design for Transponder Subsystem in the VX-SAT Communication Satellite

在线全文

学校读者我要写书评

暂无评论

Computer Aided Drafting,Design and Manufacturing 2010年第1期20卷 46-55页

作者： GUERRERO E alvarez j RIVERO L School of Electronics and Information Engineering Beijing University of Aeronautics and Astronautics

Modem communications is an indispensable tool for modem social economy and modem social life. The payload of a communication satellite provides radio relay for links between earth stations. With most commercial communication satellites the payload consists of two distinct parts with well defined interfaces： the repeater and the antennas. The repeater designates the electronic equipment which performs a range of functions on the signals from the receiving antenna before delivering them to the transmitting antenna. The VX-SAT project is a system engineering exercise, realized in the China Academy of Space Technology （CAST） with the objective of training the persons in charge of designing futures communication satellites in the Bolivarian Agency of Space Activities （ABAE） in Venezuela. This paper includes an overview of the VX-SAT system, the preliminary design of the communications payload and finally the method used to design the redundancy ring of the transponder subsystem.

关键词： communication satellite payload Ku-band redundancy ring

Molecular signature of soil organic matter under different land uses in the Lake Chaohu Basin

在线全文

学校读者我要写书评

暂无评论

Eco-Environment & Health 2022年第4期1卷 212-218页

作者： Han Gao Huixin Li Chen Lin Pedro j.j.alvarez Caroline A.Masiello Dongqiang Zhu Ao Kong Xiaolei Qu State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China School of Finance Nanjing University of Finance and EconomicsNanjing 210023China Key Laboratory of Watershed Geographic Sciences Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control Nanjing Institute of Environmental SciencesMinistry of Ecology and Environment of ChinaNanjing 210042China Department of Civil and Environmental Engineering Rice UniversityHouston TX 77005USA Department of Earth Environmental and Planetary SciencesRice UniversityHouston TX 77005USA School of Urban and Environmental Sciences Peking UniversityBeijing 100871China

The concentration and molecular composition of soil organic matter(SOM)are important factors in mitigation against climate change as well as providing other ecosystem *** quantitative understanding of how land use influences SOM molecular composition and associated turnover dynamics is limited,which underscores the need for high-throughput analytical approaches and molecular marker signatures to clarify this *** a high-throughput untargeted mass spectrometry screening and molecular markers,we show that forest,farmland and urban land uses result in distinct molecular signatures of SOM in the Lake Chaohu *** markers indicate that forest SOM has abundant carbon contents from vegetation and condensed organic carbon,leading to high soil organic carbon(SOC)*** SOM has moderate carbon contents from vegetation,and limited content of condensed organic carbon,with SOC significantly lower than that of forest *** SOM has high abundance of condensed organic carbon markers due to anthropogenic activities but relatively low in markers from ***,urban soils have the highest black carbon/SOC ratio among these land ***,our results suggested that the molecular signature of SOM varies significantly with land use in the Lake Chaohu Basin,influencing carbon *** strategy of molecular fingerprinting and marker discovery is expected to enlighten further research on SOM molecular signatures and cycling dynamics.

关键词： High-throughput untargeted mass spectrometry screening Mass spectrum processing algorithm Soil organic matter Molecular signature Land use

Gauge Invariance, the Quantum Metric Tensor and the Quantum Fidelity

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

journal of Modern Physics 2016年第13期7卷 1627-1634页

作者： j. alvarez-jiménez jose David Vergara Instituto de Ciencias Nucleares Universidad Nacional Autónoma de México Ciudad de México México

The quantum metric tensor was introduced for defining the distance in the parameter space of a system. However, it is also useful for other purposes, like predicting quantum phase transitions. Due to the physical information this tensor provides, its gauge independence sounds reasonable. Moreover, its original construction was made by looking for this gauge independence. The aim of this paper, however, is to prove that the quantum metric tensor does depend on the gauge. In addition, a real gauge invariant quantum metric tensor is introduced. A related concept is the quantum fidelity, which is also shown to depend on the gauge in this paper. The gauge dependences are explicitly shown by computing the quantum metric tensor and the quantum fidelity of the Landau problem in different gauges. Then, a real gauge independent metric tensor is proposed and computed for the same Landau problem. Since the gauge dependences have not been observed before, the results of this paper might lead to a new study of topics that are believed to be completely understood.

关键词： Landau problem Quantum Metric Tensor Gauge Dependence Quantum Fidelity