资源类型

期刊论文 1333

会议视频 64

会议信息 1

会议专题 1

年份

2024 3

2023 122

2022 132

2021 140

2020 98

2019 84

2018 72

2017 80

2016 51

2015 64

2014 44

2013 43

2012 32

2011 56

2010 50

2009 57

2008 41

2007 55

2006 33

2005 18

展开 ︾

关键词

高速铁路 14

高质量发展 8

智能制造 7

运载系统 6

创新 5

技术体系 5

能源 5

仿真 4

关键技术 4

农业科学 4

城镇建设 4

COVID-19 3

三峡工程 3

发展 3

桥梁工程 3

高压 3

高端测量仪器 3

2021全球十大工程成就 2

2022全球工程前沿 2

展开 ︾

检索范围：

排序： 展示方式：

Characterization of submicron aerosols in the urban outflow of the central Pearl River Delta region of China

Zhaoheng GONG, Zijuan LAN, Lian XUE, Liwu ZENG, Lingyan HE, Xiaofeng HUANG

《环境科学与工程前沿（英文）》 2012年 第6卷 第5期   页码 725-733 doi: 10.1007/s11783-012-0441-8

摘要： Submicron aerosol particles (with aerodynamic diameters less than 1 μm, PM ) were sampled and measured in Heshan, an urban outflow site of Guangzhou megacity in Pearl River Delta in South China, using an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) in November 2010 during 2010 Guangzhou Asian Games. The mean PM mass concentration measured was 47.9±17.0 μg·m during the campaign, with organic aerosol (OA) and sulfate being the two dominant species, accounting for 36.3% and 20.9% of the total mass, respectively, followed by black carbon (17.1%, measured by an aethalometer), nitrate (12.9%), ammonium (9.6%) and chloride (3.1%). The average size distributions of the species (except black carbon) were dominated by an accumulation mode peaking at ~550 nm. Calculations based on high-resolution organic mass spectrum showed that, C, H, O and N on average contributed 58.1%, 7.3%, 30.7%, and 3.9% to the total organic mass, respectively. The average ratio of organic mass over organic carbon mass (OM/OC) was 1.73±0.08. Four components of OA were identified by the Positive Matrix Factorization (PMF) analysis, including a hydrocarbon-like (HOA), a biomass burning (BBOA) and two oxygenated (SV-OOA and LV-OOA) organic aerosol components, which on average accounted for 18.0%, 14.3%, 28.8% and 38.9% of the total organic mass, respectively.

关键词： organic aerosol     high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS)     positive matrix factorization    

HTML PDF 收藏

Determination of persistent organic pollutants by gas chromatography/laser multiphoton ionization/time-of-flightmass spectrometry

Osamu SHITAMICHI, Taiki MATSUI, Yamei HUI, Weiwei CHEN, Totaro IMASAKA

《环境科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 26-31 doi: 10.1007/s11783-011-0374-7

摘要： An authentic mixture of polychlorinated biphenyls was measured using a short wide-bore capillary column for the group separation of major components present in an actual sample of Kanechlor. The limits of detection were improved by ca. 2 fold in comparison with those obtained using a conventional capillary column, since the retention time was reduced and the amount of analytes introduced into the mass spectrometer per unit time could be increased. On the other hand, surface-water and sediment samples containing polycyclic aromatic hydrocarbons (PAHs) were collected from the river located in the vicinity of a waste water treatment plant. Even acenaphthylene, a minor component of the mixture could be measured for the sediment sample, and the concentrations were determined for several heavy PAHs. As demonstrated, a technique involving laser multiphoton ionization/time-of-flight mass spectrometry was useful as a sensitive and selective analytical tool for the trace analysis of persistent organic pollutants in an environmental sample.

关键词： polychlorinated biphenyls (PCBs)     polycyclic aromatic hydrocarbons (PAHs)     laser multiphoton ionization/time-of-flight mass spectrometry (MPI/TOF-MS)    

HTML PDF 收藏

Single particle analysis of ambient aerosols in Shanghai during the World Exposition, 2010: two case studies

Shikang TAO, Xinning WANG, Hong CHEN, Xin YANG, Mei LI, Lei LI, Zhen ZHOU

《环境科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 391-401 doi: 10.1007/s11783-011-0355-x

摘要： A TSI Model 3800 aerosol time-of-flight mass spectrometer (ATOFMS) was deployed for single-particle analysis in Shanghai during the World Exposition (EXPO), 2010. Measurements on two extreme cases: polluted day (1st May) and clean day (25th September) were compared to show how meteorological conditions affected the concentration and composition of ambient aerosols. Mass spectra of 90496 and 50407 particles were analyzed respectively during the two sampling periods. The ART-2a neural network algorithm was applied to sort the collected particles. Seven major classes of particles were obtained: dust, sea salt, industrial, biomass burning, organic carbon (OC), elementary carbon (EC), and NH -rich particles. Number concentration of ambient aerosols showed a strong anti-correlation with the boundary layer height variation. The external mixing states of aerosols were quite different during two sampling periods because of different air parcel trajectories. Number fraction of biomass burning particles (43.3%) during polluted episode was much higher than that (21.6%) of clean time. Air parcels from the East China Sea on clean day diluted local pollutant concentration and increased the portion of sea salt particle dramatically (13.3%). The large contribution of biomass burning particles in both cases might be an indication of a constant regional background of biomass burning emission. Mass spectrum analysis showed that chemical compositions and internal mixing states of almost all the particle types were more complicate during polluted episode compared with those observed in clean time. Strong nitrate signals in the mass spectra suggested that most of the particles collected on polluted day had gone through some aging processes before reaching the sampling site.

关键词： ambient aerosol     aerosol time-of-flight mass spectrometer     Shanghai     world exposition    

HTML PDF 收藏

采用飞行时间相机的瞬态成像及其应用

Jing-yu Lin, Ri-hui Wu, Hong-man Wang, Ye-bin Liu,jylin@gxu.edu.cn,liuyebin@tsinghua.edu.cn

《信息与电子工程前沿（英文）》 2017年 第18卷 第9期   页码 1268-1276 doi: 10.1631/FITEE.1700556

摘要： 介绍了采用飞行时间（time-of-flight, ToF）相机进行瞬态成像的三种数学模型，即相关函数模型、频域模型和压缩感知模型。瞬态图像应用主要基于光传输解析和不同光路光线分离。

关键词： 瞬态成像；飞行时间（time-of-flight     ToF）；散射介质；拐角遮挡    

HTML PDF 收藏

Transient imaging with a time-of-flight cameraand its applications

Jing-yu LIN, Ri-hui WU, Hong-man WANG, Ye-bin LIU

《信息与电子工程前沿（英文）》 2017年 第18卷 第9期   页码 1268-1276 doi: .org/10.1631/FITEE.1700556

摘要： Transient imaging is a technique in photography that recordsthe process of light propagation before it reaches a stationary statesuch that events at the light speed level can be observed. In thisreview we introduce three main models for transient imaging with atime-of-flight (ToF) camera: correlation model, frequency-domain model,and compressive sensing model. Transient imaging applications usuallyinvolve resolving the problem of light transport and separating thelight rays arriving along different paths. We discuss two of the applications:imaging objects inside scattering media and recovering both the shapeand texture of an object around a corner.

关键词： Transient imaging     Time-of-flight(ToF) camera     Scattering media     Around corners    

HTML 收藏

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using a high-resolution

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1478-3

摘要：

The Large scale Urban Consumption of energ Y model was updated and coupled with WRF.

关键词： Anthropogenic heat emissions     LUCY     High-resolution     Meteorological parameters     Air quality    

HTML PDF 收藏

Identify the contribution of vehicle non-exhaust emissions: a single particle aerosol mass spectrometer

《环境科学与工程前沿（英文）》 2023年 第17卷 第5期 doi: 10.1007/s11783-023-1662-8

摘要：

● A single particle observation was conducted in a high traffic flow road environment.

关键词： Non-exhaust emissions     SPAMS     PMF     Roadside environment    

HTML PDF 收藏

Efficient, high-resolution topology optimization method based on convolutional neural networks

Liang XUE, Jie LIU, Guilin WEN, Hongxin WANG

《机械工程前沿（英文）》 2021年 第16卷 第1期   页码 80-96 doi: 10.1007/s11465-020-0614-2

摘要： Topology optimization is a pioneer design method that can provide various candidates with high mechanical properties. However, high resolution is desired for optimum structures, but it normally leads to a computationally intractable puzzle, especially for the solid isotropic material with penalization (SIMP) method. In this study, an efficient, high-resolution topology optimization method is developed based on the super-resolution convolutional neural network (SRCNN) technique in the framework of SIMP. SRCNN involves four processes, namely, refinement, path extraction and representation, nonlinear mapping, and image reconstruction. High computational efficiency is achieved with a pooling strategy that can balance the number of finite element analyses and the output mesh in the optimization process. A combined treatment method that uses 2D SRCNN is built as another speed-up strategy to reduce the high computational cost and memory requirements for 3D topology optimization problems. Typical examples show that the high-resolution topology optimization method using SRCNN demonstrates excellent applicability and high efficiency when used for 2D and 3D problems with arbitrary boundary conditions, any design domain shape, and varied load.

关键词： topology optimization     convolutional neural network     high resolution     density-based    

HTML PDF 收藏

Bridging finite element and deep learning: High-resolution stress distribution prediction in structural

Hamed BOLANDI; Xuyang LI; Talal SALEM; Vishnu Naresh BODDETI; Nizar LAJNEF

《结构与土木工程前沿（英文）》 2022年 第16卷 第11期   页码 1365-1377 doi: 10.1007/s11709-022-0882-5

摘要： Finite-element analysis (FEA) for structures has been broadly used to conduct stress analysis of various civil and mechanical engineering structures. Conventional methods, such as FEA, provide high fidelity results but require the solution of large linear systems that can be computationally intensive. Instead, Deep Learning (DL) techniques can generate results significantly faster than conventional run-time analysis. This can prove extremely valuable in real-time structural assessment applications. Our proposed method uses deep neural networks in the form of convolutional neural networks (CNN) to bypass the FEA and predict high-resolution stress distributions on loaded steel plates with variable loading and boundary conditions. The CNN was designed and trained to use the geometry, boundary conditions, and load as input to predict the stress contours. The proposed technique’s performance was compared to finite-element simulations using a partial differential equation (PDE) solver. The trained DL model can predict the stress distributions with a mean absolute error of 0.9% and an absolute peak error of 0.46% for the von Mises stress distribution. This study shows the feasibility and potential of using DL techniques to bypass FEA for stress analysis applications.

关键词： Deep Learning     finite element analysis     stress contours     structural components    

HTML PDF 收藏

广域电磁法和拟流场法精细探测技术——以井工一矿水害探测为例 Article

何继善

《工程（英文）》 2018年 第4卷 第5期   页码 667-675 doi: 10.1016/j.eng.2018.09.006

摘要：

井工一矿存在严重的老空区和水害。以往的单一勘探方法，如地震法、直流电法、音频大地电磁法、可控源音频大地电磁法、瞬变电磁法等，均未能探明老采空区范围和水害赋存情况。为了解决这个难题，联合采用广域电磁法和井- 地拟流场法的三位一体立体式探测技术，并利用三维反演电阻率资料精准获取富水区域和采空区的位置，确定了不同层位水的连通性，为井工一矿的安全生产提供了可靠的技术保障。结果合理、成效显著，释放了近4 km2 的可采面积。

关键词： 广域电磁法     拟流场法     采空区     富水性     精细探测    

HTML PDF 收藏

Urban landscape classification using Chinese advanced high-resolution satellite imagery and an object-oriented

Li-gang MA,Jin-song DENG,Huai YANG,Yang HONG,Ke WANG

《信息与电子工程前沿（英文）》 2015年 第16卷 第3期   页码 238-248 doi: 10.1631/FITEE.1400083

摘要： The Chinese ZY-1 02C satellite is one of the most advanced high-resolution earth observation systems designed for terrestrial resource monitoring. Its capability for comprehensive landscape classification, especially in urban areas, has been under constant study. In view of the limited spectral resolution of the ZY-1 02C satellite (three bands), and the complexity and heterogeneity across urban environments, we attempt to test its performance of urban landscape classification by combining a multivariable model with an object-oriented approach. The multiple variables including spectral reflection, texture, spatial autocorrelation, impervious surface fraction, vegetation, and geometry indexes were first calculated and selected using forward stepwise linear discriminant analysis and applied in the following object-oriented classification process. Comprehensive accuracy assessment which adopts traditional error matrices with stratified random samples and polygon area consistency (PAC) indexes was then conducted to examine the real area agreement between a classified polygon and its references. Results indicated an overall classification accuracy of 92.63% and a kappa statistic of 0.9124. Furthermore, the proposed PAC index showed that more than 82% of all polygons were correctly classified. Misclassification occurred mostly between residential area and barren/farmland. The presented method and the Chinese ZY-1 02C satellite imagery are robust and effective for urban landscape classification.

关键词： ZY-1 02C satellite     Classification     Urban     Multi-variable model    

HTML PDF 收藏

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0705-3

摘要： As a nondestructive testing technique, terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings (TBCs). However, the invisibility of ceramic/thermally grown oxide (TGO) reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10 μm in TBCs. To detect and monitor TGO in the emergence stage, a time of flight (TOF) improved TGO thickness measurement method is proposed. A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave. The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation. Thus, the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times. The averaged error of 1.61 μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method, making it attractive for condition monitoring and life prediction of TBCs.

关键词： thermal barrier coatings     thermally grown oxide     terahertz spectroscopy     time of flight    

HTML PDF 收藏

High resolution satellite imaging sensors for precision agriculture

Chenghai YANG

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 393-405 doi: 10.15302/J-FASE-2018226

摘要：

The central concept of precision agriculture is to manage within-field soil and crop growth variability for more efficient use of farming inputs. Remote sensing has been an integral part of precision agriculture since the farming technology started developing in the mid to late 1980s. Various types of remote sensors carried on ground-based platforms, manned aircraft, satellites, and more recently, unmanned aircraft have been used for precision agriculture applications. Original satellite sensors, such as Landsat and SPOT, have commonly been used for agricultural applications over large geographic areas since the 1970s, but they have limited use for precision agriculture because of their relatively coarse spatial resolution and long revisit time. Recent developments in high resolution satellite sensors have significantly narrowed the gap in spatial resolution between satellite imagery and airborne imagery. Since the first high resolution satellite sensor IKONOS was launched in 1999, numerous commercial high resolution satellite sensors have become available. These imaging sensors not only provide images with high spatial resolution, but can also repeatedly view the same target area. The high revisit frequency and fast data turnaround time, combined with their relatively large aerial coverage, make high resolution satellite sensors attractive for many applications, including precision agriculture. This article will provide an overview of commercially available high resolution satellite sensors that have been used or have potential for precision agriculture. The applications of these sensors for precision agriculture are reviewed and application examples based on the studies conducted by the author and his collaborators are provided to illustrate how high resolution satellite imagery has been used for crop identification, crop yield variability mapping and pest management. Some challenges and future directions on the use of high resolution satellite sensors and other types of remote sensors for precision agriculture are discussed.

关键词： high resolution satellite sensor     multispectral imagery     precision agriculture     spatial resolution     temporal resolution    

HTML PDF 收藏

Hydrothermal synthesis of crystalline α-/β-MnO2 nanorods via γ-MnOOH nanorod precursors

ZHANG Weixin, REN Xiangbin, YANG Zeheng, WANG Hua, WANG Qiang, HUANG Fei

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 365-371 doi: 10.1007/s11705-007-0066-9

摘要： The crystalline -MnO and -MnO nanorods have been successfully prepared via a facile hydrothermal method from -MnOOH nanorods precursor, respectively. The samples were characterized by means of X-ray diff raction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscope (FESEM) and Fourier transformed infrared spectra (FTIR). The morphology and structure of -MnOOH nanorods precursors have a great influence on the crystal structure of the obtained products. The -MnO nanorods are prepared from the 100°C -MnOOH precursor, while the -MnO nanorods are obtained from the 150°C -MnOOH precursor, respectively. Besides, the catalytic activity of the prepared -MnO and -MnO nanorods for the HO decomposition has been investigated comparatively, and the latter shows better catalytic activity.

关键词： obtained     -MnOOH precursor     Besides     high-resolution transmission     precursor    

HTML PDF 收藏

高分辨率光谱视频采集 Review

Lin-sen CHEN, Tao YUE, Xun CAO, Zhan MA, David J. BRADY

《信息与电子工程前沿（英文）》 2017年 第18卷 第9期   页码 1250-1260 doi: 10.1631/FITEE.1700098

摘要： 与传统视频采集技术相比，高分辨率光谱视频采集技术能够为精细农业、环境监测、遥感、军事刑侦等诸多重要领域提供高维度、高精度场景特征信息。传统光谱仪主要采用的扫描系统无法满足动态场景下的采集需求，从而限制了光谱成像技术的应用范围。近来，得益于计算摄像理论和半导体技术的快速发展，光谱视频采集技术成为可能。本文首先详细介绍了传统光谱仪的基本理论与工作原理。其次，针对光谱视频采集的核心问题，从成像理论、系统结构、关键器件等方面回顾了近年出现的瞬拍式光谱采集技术。从进一步提升光谱视频采集精度的角度出发，通过主观质量评价与客观指标比较，分析和总结了各光谱成像系统的性能优势与弊端，同时讨论了计算摄像理论、半导体制备工艺对光谱视频采集技术发展的关键作用。

关键词： 多光谱/高光谱视频采集；单次曝光；采样与重建    

HTML PDF 收藏

标题 作者 时间 类型 操作

Characterization of submicron aerosols in the urban outflow of the central Pearl River Delta region of China

Zhaoheng GONG, Zijuan LAN, Lian XUE, Liwu ZENG, Lingyan HE, Xiaofeng HUANG

期刊论文

Determination of persistent organic pollutants by gas chromatography/laser multiphoton ionization/time-of-flightmass spectrometry

Osamu SHITAMICHI, Taiki MATSUI, Yamei HUI, Weiwei CHEN, Totaro IMASAKA

期刊论文

Single particle analysis of ambient aerosols in Shanghai during the World Exposition, 2010: two case studies

Shikang TAO, Xinning WANG, Hong CHEN, Xin YANG, Mei LI, Lei LI, Zhen ZHOU

期刊论文

采用飞行时间相机的瞬态成像及其应用

Jing-yu Lin, Ri-hui Wu, Hong-man Wang, Ye-bin Liu,jylin@gxu.edu.cn,liuyebin@tsinghua.edu.cn

期刊论文

Transient imaging with a time-of-flight cameraand its applications

Jing-yu LIN, Ri-hui WU, Hong-man WANG, Ye-bin LIU

期刊论文

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using a high-resolution

期刊论文

Identify the contribution of vehicle non-exhaust emissions: a single particle aerosol mass spectrometer

期刊论文

Efficient, high-resolution topology optimization method based on convolutional neural networks

Liang XUE, Jie LIU, Guilin WEN, Hongxin WANG

期刊论文

Bridging finite element and deep learning: High-resolution stress distribution prediction in structural

Hamed BOLANDI; Xuyang LI; Talal SALEM; Vishnu Naresh BODDETI; Nizar LAJNEF

期刊论文

广域电磁法和拟流场法精细探测技术——以井工一矿水害探测为例

何继善

期刊论文

Urban landscape classification using Chinese advanced high-resolution satellite imagery and an object-oriented

Li-gang MA,Jin-song DENG,Huai YANG,Yang HONG,Ke WANG

期刊论文

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

期刊论文

High resolution satellite imaging sensors for precision agriculture

Chenghai YANG

期刊论文

Hydrothermal synthesis of crystalline α-/β-MnO2 nanorods via γ-MnOOH nanorod precursors

ZHANG Weixin, REN Xiangbin, YANG Zeheng, WANG Hua, WANG Qiang, HUANG Fei

期刊论文

高分辨率光谱视频采集

Lin-sen CHEN, Tao YUE, Xun CAO, Zhan MA, David J. BRADY

期刊论文