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基于纳米金/介孔NiO/泡沫镍纳米复合材料的微型电极用于地下水重金属检测 Article

薛博元, 杨倩, 夏楷东, 李志宏, 陈宇徽, 张大奕, 周小红

《工程(英文)》 2023年 第27卷 第8期   页码 199-208 doi: 10.1016/j.eng.2022.06.005

摘要:

Heavy metals, notably Pb2+ and Cu2+, are some of the most persistent contaminants found in groundwater. Frequent monitoring of these metals, which relies on efficient, sensitive, cost-effective, and reliable methods, is a necessity. We present a nanocomposite-based miniaturized electrode for the concurrent measurement of Pb2+ and Cu2+ by exploiting the electroanalytical technique of square wave voltammetry. We also propose a facile in situ hydrothermal calcination method to directly grow binder-free mesoporous NiO on a three-dimensional nickel foam, which is then electrochemically seeded with gold nanoparticles (AuNPs). The meticulous design of a low-barrier Ohmic contact between mesoporous NiO and AuNPs facilitates target-mediated nanochannel-confined electron transfer within mesoporous NiO. As a result, the heavy metals Pb2+ (0.020 mg·L−1 detection limit, 2.0–16.0 mg·L−1 detection range) and Cu2+ (0.013 mg·L−1 detection limit, 0.4–12.8 mg·L−1 detection range) can be detected simultaneously with high precision. Furthermore, other heavy metal ions and common interfering ions found in groundwater showed negligible impacts on the electrode's performance, and the recovery rate of groundwater samples varied between 96.3% ± 2.1% and 109.4% ± 0.6%. The compactness, flexible shape, low power consumption, and ability to remotely operate our electrode pave the way for onsite detection of heavy metals in groundwater, thereby demonstrating the potential to revolutionize the field of environmental monitoring.

关键词: AuNPs     Mesoporous NiO     Miniaturized electrode     Heavy metal ions     Groundwater     Square wave voltammetry    

Existence of complete band gaps in 2D steel-water phononic crystal with square lattice

Cunfu HE, Huanyu ZHAO, Ruiju WEI, Bin WU

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 450-454 doi: 10.1007/s11465-010-0105-y

摘要: This paper theoretically and experimentally studies the existence of complete band gaps in two-dimensional (2D) phononic crystal consisting of parallel steel rods in water with square lattice. The band structure of phononic crystal is calculated by a plane wave expansion (PWE) method. Based on the well-known ultrasonic immersion transmission technique, the overlapping transmission spectra of acoustic waves, a complete band gap, is experimentally measured along the two high-symmetry directions of the first irreducible Brillouin zone. There is a very good agreement between the experimental result and the range of frequencies of the complete band gap.

关键词: phononic crystal     plane wave expansion (PWE) method     experimental study    

基于刚性与非刚性Square-Twist胞元混合排布的折纸超材料设计与性能编程研究 Article

马家耀, 臧世玺, 陈焱, 由衷

《工程(英文)》 2022年 第17卷 第10期   页码 82-92 doi: 10.1016/j.eng.2022.02.015

摘要: 本文通过将一系列不同类型的square-twist 折纸胞元进行空间排布,设计了一种新型折纸超材料。首先建立了超材料胞元的空间排布规则,保证了相邻胞元山-谷线折痕的几何匹配。

关键词: 折纸超材料     超材料     square-twist折纸     非周期性排布     可编程性    

Usability perceptions and beliefs about smart thermostats by chi-square test, signal detection theory

Pedro PONCE, Therese PEFFER, Arturo MOLINA

《能源前沿(英文)》 2019年 第13卷 第3期   页码 522-538 doi: 10.1007/s11708-018-0562-2

摘要: It is well known that smart thermostats (STs) have become key devices in the implementation of smart homes; thus, they are considered as primary elements for the control of electrical energy consumption in households. Moreover, energy consumption is drastically affected when the end users select unsuitable STs or when they do not use the STs correctly. Furthermore, in future, Mexico will face serious electrical energy challenges that can be considerably resolved if the end users operate the STs in a correct manner. Hence, it is important to carry out an in-depth study and analysis on thermostats, by focusing on social aspects that influence the technological use and performance of the thermostats. This paper proposes the use of a signal detection theory (SDT), fuzzy detection theory (FDT), and chi-square (CS) test in order to understand the perceptions and beliefs of end users about the use of STs in Mexico. This paper extensively shows the perceptions and beliefs about the selected thermostats in Mexico. Besides, it presents an in-depth discussion on the cognitive perceptions and beliefs of end users. Moreover, it shows why the expectations of the end users about STs are not met. It also promotes the technological and social development of STs such that they are relatively more accepted in complex electrical grids such as smart grids.

关键词: thermostats     perceptions     beliefs     signal detection theory (SDT)     fuzzy signal detection theory (FSDT)     chi-square (CS) test    

Theoretical study on the confine-stiffening effect and fractal cracking of square concrete filled steel

《结构与土木工程前沿(英文)》 2021年 第15卷 第6期   页码 1317-1336 doi: 10.1007/s11709-021-0763-3

摘要: Tension stress in steel-concrete composite is widely observed in engineering design. Based on an experimental program on tension performance of three square concrete-filled tubes (SCFT), the tension theory of SCFT is proposed using a mechanics-based approach. The tension stiffening effect, the confining strengthening effect and the confining stiffening effect, observed in tests of SCFTs are included in the developed tension theory model. Subsequently, simplified constitutive models of steel and concrete are proposed for the axial tension performance of SCFT. Based on the MSC.MARC software, a special fiber beam-column element is proposed to include the confining effect of SCFTs under tension and verified. The proposed analytical theory, effective formulas, and equivalent constitutive laws are extensively verified against three available tests reported in the literature on both global level (e.g., load-displacement curves) and strain level. The experimental verification proves the accuracy of the proposed theory and formulations in simulating the performance of SCFT members under tension with the capability to accurately predict the tensile strength and stiffness enhancements and realistically simulate the fractal cracking phenomenon.

关键词: square concrete filled tubes     confine-stiffening     confine-strengthening     fractal cracking     fracture    

Study on wave rotor refrigerators

Yuqiang DAI, Dapeng HU, Meixia DING

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 83-87 doi: 10.1007/s11705-009-0075-y

摘要: As a novel generation of a rotational gas wave machine, the wave rotor refrigerator (WRR) is an unsteady flow device used for refrigeration, in whose passages pressured streams directly contact and exchange energy due to the movement of pressure waves. In this paper, the working mechanism and refrigeration principle are investigated based on the one-dimensional unsteady flow theory. A basic limitation on main structural parameters and operating parameters is deduced and the wave diagram of WRR to guide designing is sketched. The main influential factors are studied through an experiment. In the DUT Gas Wave Refrigeration Studying and Development Center (GWRSDC) lab, the isentropic efficiency can now reach about 65%. The results show that the WRR is a feasible and promising technology in pressured gas refrigeration cases.

关键词: wave rotor     refrigeration     unsteady flow theory     wave diagram    

Prediction of the shear wave velocity

Amoroso SARA

《结构与土木工程前沿(英文)》 2014年 第8卷 第1期   页码 83-92 doi: 10.1007/s11709-013-0234-6

摘要: The paper examines the correlations to obtain rough estimates of the shear wave velocity from non-seismic dilatometer tests (DMT) and cone penetration tests (CPT). While the direct measurement of is obviously preferable, these correlations may turn out useful in various circumstances. The experimental results at six international research sites suggest that the DMT predictions of from the parameters (material index), (horizontal stress index), (constrained modulus) are more reliable and consistent than the CPT predictions from (cone resistance), presumably because of the availability, by DMT, of the stress history index .

关键词: horizontal stress index     shear wave velocity     flat dilatometer test     cone penetration test    

Lamb wave propagation modeling for structure health monitoring

Xiaoyue ZHANG, Shenfang YUAN, Tong HAO

《机械工程前沿(英文)》 2009年 第4卷 第3期   页码 326-331 doi: 10.1007/s11465-009-0045-6

摘要: This study aims to model the propagation of Lamb waves used in structure health monitoring. A number of different numerical computational techniques have been developed for wave propagation studies. The local interaction simulation approach, used for modeling sharp interfaces and discontinuities in complex media (LISA/SIM theory), has been effectively applied to numerical simulations of elastic wave interaction. This modeling is based on the local interaction simulation approach theory and is finally accomplished through the finite elements software Ansys11. In this paper, the Lamb waves propagating characteristics and the LISA/SIM theory are introduced. The finite difference equations describing wave propagation used in the LISA/SIM theory are obtained. Then, an anisotropic metallic plate model is modeled and a simulating Lamb waves signal is loaded on. Finally, the Lamb waves propagation modeling is implemented.

关键词: Lamb wave     modeling     LISA/SIM theory     finite difference equation     finite element    

Day-ahead electricity price forecasting using back propagation neural networks and weighted least square

S. Surender REDDY,Chan-Mook JUNG,Ko Jun SEOG

《能源前沿(英文)》 2016年 第10卷 第1期   页码 105-113 doi: 10.1007/s11708-016-0393-y

摘要: This paper proposes the day-ahead electricity price forecasting using the artificial neural networks (ANN) and weighted least square (WLS) technique in the restructured electricity markets. Price forecasting is very important for online trading, e-commerce and power system operation. Forecasting the hourly locational marginal prices (LMP) in the electricity markets is a very important basis for the decision making in order to maximize the profits/benefits. The novel approach proposed in this paper for forecasting the electricity prices uses WLS technique and compares the results with the results obtained by using ANNs. To perform this price forecasting, the market knowledge is utilized to optimize the selection of input data for the electricity price forecasting tool. In this paper, price forecasting for Pennsylvania-New Jersey-Maryland (PJM) interconnection is demonstrated using the ANNs and the proposed WLS technique. The data used for this price forecasting is obtained from the PJM website. The forecasting results obtained by both methods are compared, which shows the effectiveness of the proposed forecasting approach. From the simulation results, it can be observed that the accuracy of prediction has increased in both seasons using the proposed WLS technique. Another important advantage of the proposed WLS technique is that it is not an iterative method.

关键词: day-ahead electricity markets     price forecasting     load forecasting     artificial neural networks     load serving entities    

最小二乘支持向量机的扩展及其在时间序列预测中的应用

向小东

《中国工程科学》 2008年 第10卷 第11期   页码 89-92

摘要:

根据时间序列近期数据较远期数据包含有更多未来信息的思想,对最小二乘支持向量机预测方法进行了扩展,得到了更具一般性的最小二乘支持向量机预测模型,给出了扩展后的预测模型具体算法。两个时间序列的预测实例表明,扩展后的预测方法获得了更好的预测效果,提升了最小二乘支持向量机预测方法的价值。

关键词: 最小二乘支持向量机     扩展     时间序列     预测    

A way to explain the thermal boundary effects on laminar convection through a square duct

Liangbi WANG, Xiaoping GAI, Kun HUANG, Yongheng ZHANG, Xiang YANG, Xiang WU

《能源前沿(英文)》 2010年 第4卷 第4期   页码 496-506 doi: 10.1007/s11708-010-0020-2

摘要: A way using the reformulation of the energy conservation equation in terms of heat flux to explain the thermal boundary effects on laminar convective heat transfer through a square duct is presented. For a laminar convection through a square duct, it explains that on the wall surface, the velocity is zero, but convection occurs for uniform wall heat flux (UWHF) boundary in the developing region due to the velocity gradient term; for uniform wall temperature (UWT) boundary, only diffusion process occurs on the wall surface because both velocity and velocity gradient do not contribute to convection; for UWHF, the largest term of the gradient of velocity components (the main flow velocity) on the wall surface takes a role in the convection of the heat flux normal to the wall surface, and this role exists in the fully developed region. Therefore, a stronger convection process occurs for UWHF than for UWT on the wall surface. The thermal boundary effects on the laminar convection inside the flow are also detailed.

关键词: convective transport     heat transfer     mass transfer     laminar flow     thermal boundary effects    

Numerical study on natural convection in a square enclosure containing a rectangular heated cylinder

Jianhua LU, Zhaoli GUO, Zhenhua CHAI, Baochang SHI,

《能源前沿(英文)》 2009年 第3卷 第4期   页码 373-380 doi: 10.1007/s11708-009-0078-x

摘要: In this paper, the natural convection in a square enclosure with a rectangular heated cylinder is investigated via the lattice Boltzmann method. A detailed study is conducted on the effect of the cylinder width and the Rayleigh number on the fluid flow and heat transfer. The flow structures and heat transfer patterns are classified into eight buoyant regimes, i.e., four steady regimes, two periodic regimes, one multiple periodic regime, and one chaos regime, two of which are reported for the first time.

关键词: natural convection     buoyant regime     heated cylinder     lattice Boltzmann    

Vanadium and molybdenum concentrations in particulate from Palermo (Italy): analytical methods using voltammetry

Diana AMORELLO,Santino ORECCHIO

《环境科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 605-614 doi: 10.1007/s11783-014-0703-8

摘要: The main purpose of this work was to develop a reliable method for the determination of vanadium (V) and molybdenum (Mo) in atmosphere particles or aerosols because they can not be readily measured using conventional techniques. For this research, 30 particulate samples were collected from five different stations located at Palermo, Italy. We used the catalytic adsorptive stripping voltammetry and differential pulsed voltammetry to measure V and Mo in atmospheric particulate, respectively. The represented method includes advantages of high sensitivity, high selectivity, simplicity, reproducibility, speed and low costs. The quantification limits for V and Mo are, respectively, 0.57 and 0.80 ng·m . The precision, expressed as relative standard deviation (RSD %), was about 2% for both metals. The mean recoveries of added V and Mo were about 99.5% and ranged from 97% to 101%. Vanadium concentrations in particulate samples collected in Palermo area ranged from 0.57 to 7.7 ng·m , while Mo concentrations were in the range 0.8–51 ng·m . In many cases the concentrations of two elements in the particulate samples fall below the detection limits. The mean concentrations for V and Mo in particulate samples, collected in Palermo area, were respectively 3.1 and 5.9 ng·m .

关键词: vanadium     molybdenum     particulate     voltammetry     Palermo    

Electrochemical reduction characteristics and the mechanism of chlorinated hydrocarbons at the copper electrode

XU Wenying, GAO Tingyao, ZHOU Rongfeng, MA Lumin

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 207-212 doi: 10.1007/s11783-007-0036-y

摘要: The electrochemical reduction characteristics of chlorinated hydrocarbons were investigated by cyclic voltammetry technique. The reduction mechanism and activity of the chlorinated hydrocarbons at the copper electrode were explored. The relationship between the structure of chlorinated hydrocarbons and their reductive activity were discussed. The experimental results showed that chlorinated alkanes and a portion of chlorinated aromatic hydrocarbons could be reduced directly at the copper electrode. However, chlorinated aromatic hydrocarbons were not easy to reduce at the copper electrode. The results provided a theoretical basis for the catalyzed iron inner electrolysis method.

关键词: electrolysis     chlorinated     relationship     mechanism     voltammetry technique    

A simple multi-wave algorithm for the uncapacitated facility location problem

Fred GLOVER, Saïd HANAFI, Oualid GUEMRI, Igor CREVITS

《工程管理前沿(英文)》 2018年 第5卷 第4期   页码 451-465 doi: 10.15302/J-FEM-2018038

摘要:

The multi-wave algorithm (Glover, 2016) integrates tabu search and strategic oscillation utilizing repeated waves (nested iterations) of constructive search or neighborhood search. We propose a simple multi-wave algorithm for solving the Uncapacitated Facility Location Problem (UFLP) to minimize the combined costs of selecting facilities to be opened and of assigning each customer to an opened facility in order to meet the customers’ demands. The objective is to minimize the overall cost including the costs of opening facilities and the costs of allocations. Our experimental tests on a standard set of benchmarks for this widely-studied class of problems show that our algorithm outperforms all previous methods.

关键词: discrete optimization     UFLP     multi-wave optimization     strategic oscillation     tabu search    

标题 作者 时间 类型 操作

基于纳米金/介孔NiO/泡沫镍纳米复合材料的微型电极用于地下水重金属检测

薛博元, 杨倩, 夏楷东, 李志宏, 陈宇徽, 张大奕, 周小红

期刊论文

Existence of complete band gaps in 2D steel-water phononic crystal with square lattice

Cunfu HE, Huanyu ZHAO, Ruiju WEI, Bin WU

期刊论文

基于刚性与非刚性Square-Twist胞元混合排布的折纸超材料设计与性能编程研究

马家耀, 臧世玺, 陈焱, 由衷

期刊论文

Usability perceptions and beliefs about smart thermostats by chi-square test, signal detection theory

Pedro PONCE, Therese PEFFER, Arturo MOLINA

期刊论文

Theoretical study on the confine-stiffening effect and fractal cracking of square concrete filled steel

期刊论文

Study on wave rotor refrigerators

Yuqiang DAI, Dapeng HU, Meixia DING

期刊论文

Prediction of the shear wave velocity

Amoroso SARA

期刊论文

Lamb wave propagation modeling for structure health monitoring

Xiaoyue ZHANG, Shenfang YUAN, Tong HAO

期刊论文

Day-ahead electricity price forecasting using back propagation neural networks and weighted least square

S. Surender REDDY,Chan-Mook JUNG,Ko Jun SEOG

期刊论文

最小二乘支持向量机的扩展及其在时间序列预测中的应用

向小东

期刊论文

A way to explain the thermal boundary effects on laminar convection through a square duct

Liangbi WANG, Xiaoping GAI, Kun HUANG, Yongheng ZHANG, Xiang YANG, Xiang WU

期刊论文

Numerical study on natural convection in a square enclosure containing a rectangular heated cylinder

Jianhua LU, Zhaoli GUO, Zhenhua CHAI, Baochang SHI,

期刊论文

Vanadium and molybdenum concentrations in particulate from Palermo (Italy): analytical methods using voltammetry

Diana AMORELLO,Santino ORECCHIO

期刊论文

Electrochemical reduction characteristics and the mechanism of chlorinated hydrocarbons at the copper electrode

XU Wenying, GAO Tingyao, ZHOU Rongfeng, MA Lumin

期刊论文

A simple multi-wave algorithm for the uncapacitated facility location problem

Fred GLOVER, Saïd HANAFI, Oualid GUEMRI, Igor CREVITS

期刊论文