资源类型

期刊论文 282

会议视频 7

会议信息 1

年份

2023 24

2022 33

2021 26

2020 13

2019 25

2018 10

2017 17

2016 18

2015 16

2014 13

2013 9

2012 15

2011 14

2010 9

2009 9

2008 9

2007 13

2006 4

2005 4

2003 1

展开 ︾

关键词

节能减排 4

环境 3

碳中和 3

DSM（设计结构矩阵） 2

可持续发展 2

情景分析 2

混合基质膜 2

细胞外基质 2

2型糖尿病 1

CFRP索斜拉桥 1

CO2 EOR 1

CO2净排放量 1

CO2封存 1

Cuk矩阵变换器 1

Electron 1

Gossip模型 1

Kaya 恒等式 1

MCDB 1

Matlab仿真 1

展开 ︾

检索范围：

排序： 展示方式：

Excitation-emission matrix (EEM) fluorescence spectroscopy for characterization of organic matter in

Jinlan Yu, Kang Xiao, Wenchao Xue, Yue-xiao Shen, Jihua Tan, Shuai Liang, Yanfen Wang, Xia Huang

《环境科学与工程前沿（英文）》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1210-8

摘要： • Principles and methods for fluorescence EEM are systematically outlined. • Fluorophore peak/region/component and energy information can be extracted from EEM. • EEM can fingerprint the physical/chemical/biological properties of DOM in MBRs. • EEM is useful for tracking pollutant transformation and membrane retention/fouling. • Improvements are still needed to overcome limitations for further studies. The membrane bioreactor (MBR) technology is a rising star for wastewater treatment. The pollutant elimination and membrane fouling performances of MBRs are essentially related to the dissolved organic matter (DOM) in the system. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy, a powerful tool for the rapid and sensitive characterization of DOM, has been extensively applied in MBR studies; however, only a limited portion of the EEM fingerprinting information was utilized. This paper revisits the principles and methods of fluorescence EEM, and reviews the recent progress in applying EEM to characterize DOM in MBR studies. We systematically introduced the information extracted from EEM by considering the fluorescence peak location/intensity, wavelength regional distribution, and spectral deconvolution (giving fluorescent component loadings/scores), and discussed how to use the information to interpret the chemical compositions, physiochemical properties, biological activities, membrane retention/fouling behaviors, and migration/transformation fates of DOM in MBR systems. In addition to conventional EEM indicators, novel fluorescent parameters are summarized for potential use, including quantum yield, Stokes shift, excited energy state, and fluorescence lifetime. The current limitations of EEM-based DOM characterization are also discussed, with possible measures proposed to improve applications in MBR monitoring.

关键词： excitation-emission matrix (EEM)     dissolved organic matter (DOM)     membrane bioreactor (MBR)     fluorescence indicator     characterization method    

HTML PDF 收藏

Identification of sources, characteristics and photochemical transformations of dissolved organic matter with EEM-PARAFAC

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1340-z

摘要：

• The source of DOM in surface water and sediment is inconsistent.

关键词： Dissolved organic matter     Parallel factor analysis     Excitation-emission matrices     Photodegradation    

HTML PDF 收藏

A chemometric analysis on the fluorescent dissolved organic matter in a full-scale sequencing batch reactor for municipal wastewater treatment

Chen Qian, Wei Chen, Wei-Hua Li, Han-Qing Yu

《环境科学与工程前沿（英文）》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0962-2

摘要： Rapid monitoring of water quality is crucial to the operation of municipal wastewater treatment plants (WWTPs). Fluorescence excitation-emission matrix (EEM) in combination with parallel factor analysis (PARAFAC) has been used as a powerful tool for the characterization of dissolved organic matter (DOM) in WWTPs. However, a recent work has revealed the drawback of PARAFAC analysis, i.e., overestimating the component number. A novel method, parallel factor framework-clustering analysis (PFFCA), has been developed in our earlier work to resolve this drawback of PARAFAC. In the present work, both PARAFAC and PFFCA were used to analyze the EEMs of water samples from a full-scale WWTP from a practical application point of view. The component number and goodness-of-fit from these two methods were compared and the relationship between the relative score change of component and the actual concentration was investigated to evaluate the estimation error introduced by both methods. PFFCA score and actual concentration exhibited a higher correlation coefficient ( = 0.870) compared with PARAFAC ( <0.771), indicating that PFFCA provided a more accurate relative change estimation than PARAFAC. The results suggest that use of PARAFAC may cause confusion in selecting the component number, while EEM-PFFCA is a more reliable alternative approach for monitoring water quality in WWTPs.

关键词： Wastewater treatment plants (WWTPs)     Excitation-emission matrix (EEM)     Parallel factor (PARAFAC)     Parallel factor framework-clustering analysis (PFFCA)    

HTML PDF 收藏

Interactions between metal ions and the biopolymer in activated sludge: quantification and effects of system pH value

Yun Zhou, Siqing Xia, Binh T. Nguyen, Min Long, Jiao Zhang, Zhiqiang Zhang

《环境科学与工程前沿（英文）》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0898-6

摘要： The biopolymer showed two protein-like fluorescence peaks (peaks A and B). Interactions of Pb(II) and biopolymer were quantified at various system pH values. System pH values significantly affect the quenching constant values for both peaks. Peak B plays a more important role in the interactions than peak A. Removal mechanism of metal ions by activated sludge system was further disclosed. The quantification and effects of system pH value on the interactions between Pb(II) and the biopolymer from activated sludge were investigated. The biopolymer had two protein-like fluorescence peaks (Ex/Em= 280 nm/326–338 nm for peak A; Ex/Em= 220–230 nm/324–338 nm for peak B). The fluorescence intensities of peak B were higher than those of peak A. The fluorophores of both peaks could be largely quenched by Pb(II), and the quencher dose for peak B was about half of that for peak A. The modified Stern-Volmer equation well depicted the fluorescence quenching titration. The quenching constant (Ka) values for both peaks decreased with rising system pH value, and then sharply decreased under alkaline conditions. It could be attributed to that the alkaline conditions caused the reduction of available Pb(II) due to the occurrence of Pb(OH)2 sediments. The Ka values of peak B were bigger than those for peak A at the same system pH values. Accordingly, the aromatic protein (peak B) plays the key role in the interactions between metal ions and the biopolymer.

关键词： Metal ions     Biopolymer     Activated sludge     Three-dimensional excitation emission matrix (3D-EEM)     Fluorescence regional integration (FRI) technique     Quantification    

HTML PDF 收藏

Investigation of fluorescence characterization and electrochemical behavior on the catalysts of nanosized Pt-Rh/γ-Al

Chang-Mao HUNG, Wen-Liang LAI, Jane-Li LIN

《环境科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 428-434 doi: 10.1007/s11783-013-0517-0

摘要： This work describes the environmentally friendly technology for oxidation of ammonia (NH ) to form nitrogen at temperatures range from 423K to 673K by selective catalytic oxidation (SCO) over a nanosized Pt-Rh/γ-Al O catalyst prepared by the incipient wetness impregnation method of hexachloroplatinic acid (H PtCl ) and rhodium (III) nitrate (Rh(NO ) ) with γ-Al O in a tubular fixed-bed flow quartz reactor (TFBR). The characterization of catalysts were thoroughly measured using transmission electron microscopy (TEM), three-dimensional excitation-emission fluorescent matrix (EEFM) spectroscopy, UV-Vis absorption, dynamic light-scattering (DLS), zeta potential meter, and cyclic voltammetry (CV). The results demonstrated that at a temperature of 673K and an oxygen content of 4%, approximately 99% of the NH was removed by catalytic oxidation over the nanosized Pt-Rh/γ-Al O catalyst. N was the main product in NH -SCO process. Further, it reveals that the oxidation of NH was proceeds by the over-oxidation of NH into NO, which was conversely reacted with the NH to yield N . Therefore, the application of nanosized Pt-Rh/γ-Al O catalyst can significantly enhance the catalytic activity toward NH oxidation. One fluorescent peak for fresh catalyst was different with that of exhausted catalyst. It indicates that EEFM spectroscopy was proven to be an appropriate and effective method to characterize the Pt clusters in intrinsic emission from nanosized Pt-Rh/γ-Al O catalyst. Results obtained from the CV may explain the significant catalytic activity of the catalysts.

关键词： ammonia (NH3)     nanosized Pt-Rh/γ-Al2O3 catalyst     excitation-emission fluorescent matrix (EEFM)     selective catalytic oxidation (SCO)     tubular fixed-bed reactor (TFBR)    

HTML PDF 收藏

Chemical identification and genotoxicity analysis of petrochemical industrial wastewater

Jing ZHANG, Shigong WANG, Can WANG, Hongying HU

《环境科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 350-359 doi: 10.1007/s11783-012-0404-0

摘要： The actual harmful effects of industrial wastewater can not be reflected by the conventional water quality index. Therefore, the change in dissolved organic matter and the genetic toxicity of petrochemical wastewater were observed in the current study by examining the wastewater treatment plant of a large petrochemical enterprise in Northwest China. Using XAD-8, MSC, and DA-7 resins, the wastewater was separated into six fractions, namely, hydrophobic acid (HOA), hydrophobic neutral (HOB), hydrophobic alkaline, hydrophilic acid, hydrophilic alkaline, and hydrophilic neutral. Umu-test was used to detect the genetic toxicity of the wastewater samples, and fluorescence spectra were also obtained to examine genetic toxic substances. The results show that wastewater treatment facilities can effectively reduce the concentration of organic matter in petrochemical wastewater ( <0.05). However, the mixing of aniline wastewater can increase the amount of organic carbon ( <0.05) and can overload facilities. This finding shows that the mixed collection and joint treatment of different types of petrochemical wastewater can affect the water quality of the effluent. Particularly, hydrophobic substances can be difficult to remove and account for a relatively large proportion of the effluent. The mixture of aniline wastewater can increase the genetic toxicity of the effluent ( <0.05), and biologic treatment can not effectively decrease the toxicity. Most of the genetic toxicology may exist in the HOA and HOB fractions. Fluorescence spectroscopy also confirms this result, and tryptophan-like substances may play an important role in genetic toxicity.

关键词： dissolved organic matter     resin fraction     genetic toxicity     fluorescence excitation and emission matrix    

HTML PDF 收藏

Characterization of the dissolved organic matter in sewage effluent of sequence batch reactor: the impact of carbon source

Jin GUO, Feng SHENG, Jianhua GUO, Xiong YANG, Mintao MA, Yongzhen PENG

《环境科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 280-287 doi: 10.1007/s11783-011-0336-0

摘要： Dissolved organic matter (DOM) transformation in sequence batch reactor (SBR) fed with carbon sources of different biodegradability was investigated. During the biologic degradation process, the low molecular weight (MW) fraction (<1 kDa) gradually decreased, while the refractory compounds with higher aromaticity were aggregated. Size exclusion chromatography (SEC) and fluorescence of excitation emission matrices (EEM) demonstrated that more biopolymers (polysaccharides or proteins) and humic-like substances were presented in the extracellular polymeric substance (EPS) extracted from the SBR fed with sodium acetate or glucose, while the EPS from SBR fed with slowly biodegradable dissolved organic carbon (DOC) substrate-starch had relatively less biopolymers. Comparing the EfOM in sewage effluent of three SBRs, the effluent from SBR fed with starch is more aromatic. Organic carbon with MW>1 kDa as well as the hydrophobic fraction in DOM gradually increased with the carbon sources changing from sodium acetate to glucose and starch. The DOC fractionation and the EEM all demonstrated that EfOM from the effluent of the SBR fed with starch contained more fulvic acid-like substances comparing with the SBR fed with sodium acetate and glucose.

关键词： effluent organic matter (EfOM)     extracellular polymeric substance (EPS)     molecular weight distribution (MWD)     hydrophobic     hydrophilic     excitation emission matrices (EEM)    

HTML PDF 收藏

Approximation of structural damping and input excitation force

Mohammad SALAVATI

《结构与土木工程前沿（英文）》 2017年 第11卷 第2期   页码 244-254 doi: 10.1007/s11709-016-0371-9

摘要： Structural dynamic characteristics are the most significant parameters that play a decisive role in structural damage assessment. The more sensitive parameter to the damage is the damping behavior of the structure. The complexity of structural damping mechanisms has made this parameter to be one of the ongoing research topics. Despite all the difficulties in the modeling of damping, there are some approaches like as linear and nonlinear models which are described as the energy dissipation throughout viscous, material or structural hysteretic and frictional damping mechanisms. In the presence of a mathematical model of the damping mechanisms, it is possible to estimate the damping ratio from the theoretical comparison of the damped and un-damped systems. On the other hand, solving the inverse problem of the input force estimation and its distribution to each SDOFs, from the measured structural responses plays an important role in structural identification process. In this paper model-based damping approximation method and a model-less structural input estimation are considered. The effectiveness of proposed methods has been carried out through analytical and numerical simulation of the lumped mass system and the results are compared with reference data. Consequently, high convergence of the comparison results illustrates the satisfactory of proposed approximation methods.

关键词： structural modal parameters     damping identification method     input excitation force identification     Inverse problem    

HTML PDF 收藏

Decellularized extracellular matrix mediates tissue construction and regeneration

《医学前沿（英文）》 2022年 第16卷 第1期   页码 56-82 doi: 10.1007/s11684-021-0900-3

摘要： Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell–matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.

关键词： decellularized extracellular matrix     3D culture     organoids     tissue repair    

HTML PDF 收藏

同步发电机励磁系统中PWM控制的仿真研究

贾贵玺,徐伟,郭宝钥,张臣堂

《中国工程科学》 2005年 第7卷 第6期   页码 50-53

摘要：

优良的励磁控制系统不仅可以保证发电机运行的可靠性和稳定性，而且可有效地提髙发电机和电力系统技术指标。同步发电机励磁系统采用了PWM整流技术，实现励磁电流低谐波和励磁功率单元高功率因数转换，提高了发电机供电质量，并用MATLAB对设计系统做出仿真验证，证明该设计对改善发电机输出电压、提高功率单元电能利用率有明显效果。

关键词： PWM     高功率因数     励磁系统     Matlab仿真    

HTML PDF 收藏

Perspective of mixed matrix membranes for carbon capture

Shinji Kanehashi, Colin A. Scholes

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 460-469 doi: 10.1007/s11705-019-1881-5

摘要： Polymeric membrane-based gas separation has found wide applications in industry, such as carbon capture, hydrogen recovery, natural gas sweetening, as well as oxygen enrichment. Commercial gas separation membranes are required to have high gas permeability and selectivity, while being cost-effective to process. Mixed matrix membranes (MMMs) have a composite structure that consists of polymers and fillers, therefore featuring the advantages of both materials. Much effort has been made to improve the gas separation performance of MMMs as well as general membrane properties, such as mechanical strength and thermal stability. This perspective describes potential use of MMMs for carbon capture applications, explores their limitations in fabrication and methods to overcome them, and addresses their performance under industry gas conditions.

关键词： membranes     polymeric     mixed matrix     impurities    

HTML PDF 收藏

一种基于子带激励替换的窄带语音水印算法 Article

Wei LIU, Ai-qun HU

《信息与电子工程前沿（英文）》 2017年 第18卷 第5期   页码 627-643 doi: 10.1631/FITEE.1601503

摘要： 本文建议了一种新的窄带语音水印算法，该算法将部分语音信号替换为一个经过幅度调节和频谱成形的隐蔽信号。文中从理论上证明了若仅对一小部分载体语音作修改，则不但可以建立一个用于隐蔽通信的理想信道模型，而且还能确保隐藏信号的不可感知性和带水印信号的可懂度。在此基础上，文中建议了一个实际的系统模型。在嵌入器中，使用了能量规范化准则，使得通带水印信号的能量与原始通带语音激励信号的能量相等，然后使用合成滤波器来对该水印信号进行频谱成形。在提取器中，先用带通滤波器去除带外信号，然后用分析滤波器对失真进行补偿。实验结果显示，本文建议算法的数据速率可达400 bits/s，具有更佳的带宽效率，且有良好的不可感知性。此外，该算法对实际应用中的各种攻击也是顽健的。

关键词： 分析滤波器；线性预测；窄带语音水印；通带激励替代；能量规范化；谱包络成形；合成滤波器    

HTML PDF 收藏

A new prediction method of industrial atmospheric pollutant emission intensity based on pollutant emission

《环境科学与工程前沿（英文）》 2023年 第17卷 第1期 doi: 10.1007/s11783-023-1608-1

摘要：

● Established a quantification method of pollutant emission standard.

关键词： Industrial atmospheric pollutants     Pollutant emission standards     Quantitative method     Machine learning     Single enterprise    

HTML PDF 收藏

Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated

《结构与土木工程前沿（英文）》   页码 1100-1116 doi: 10.1007/s11709-023-0967-9

摘要： The performance of a new fiber-reinforced cementitious matrix (FRCM) system developed using custom-designed mortar and fabrics is investigated in this study. The behavior of this system is evaluated in terms of both the flexural and shear strengthening of reinforced concrete beams. Eight beams are designed to assess the effectiveness of the FRCM system in terms of flexural strengthening, and four specimens are designed to investigate their shear behavior. The parameters investigated for flexural strengthening are the number of layers, span/depth ratio, and the strengthening method. Unlike previous studies, custom fabrics with similar axial stiffness are used in all strengthening methods in this study. In the shear-strengthened specimens, the effects of the span/depth ratio and strengthening system type (fiber-reinforced polymer (FRP) or FRCM) are investigated. The proposed FRCM system exhibits desirable flexural and shear strengthening for enhancing the load capacity, provides sufficient bonding with the substrate, and prevents premature failure modes. Considering the similar axial stiffness of fabrics used in both FRCM and FRP systems and the higher load capacity of specimens strengthened by the former, cement-based mortar performs better than epoxy.

关键词： fiber-reinforced cementitious matrix     flexural strengthening     shear strengthening     carbon fiber-reinforced polymer     shear span    

HTML PDF 收藏

A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

《机械工程前沿（英文）》 2013年 第8卷 第4期   页码 360-366 doi: 10.1007/s11465-013-0280-8

摘要：

Mobile concrete pump boom is typical multi-body large-scale motion manipulator. Due to posture constantly change in working process, kinematic rule and dynamic characteristic are difficult to solve. A dynamics model of a mobile concrete pump boom is established based on discrete time transfer matrix method (DTTMM). The boom system is divided into sub-structure A and sub-structure B. Sub-structure A is composed by the 1st boom and hydraulic actuator as well as the support. And sub-structure B is consists of the other three booms and corresponding hydraulic actuators. In the model, the booms and links are regarded as rigid elements and the hydraulic cylinders are equivalent to spring-damper. The booms are driven by the controllable hydraulic actuators. The overall dynamic equation and transfer matrix of the model can be assembled by sub-structures A and B. To get a precise result, step size and integration parameters are studied then. Next the tip displacement is calculated and compared with the result of ADAMS software. The displacement and rotation angle curves of the proposed method fit well with the ADAMS model. Besides it is convenient in modeling and saves time. So it is suitable for mobile concrete pump boom real-time monitoring and dynamic analysis. All of these provide reference to boom optimize and engineering application of such mechanisms.

关键词： multi-body     mobile concrete pump boom     discrete time transfer matrix method (DTTMM)     kinematic     dynamic     tip displacement    

HTML PDF 收藏

标题 作者 时间 类型 操作

Excitation-emission matrix (EEM) fluorescence spectroscopy for characterization of organic matter in

Jinlan Yu, Kang Xiao, Wenchao Xue, Yue-xiao Shen, Jihua Tan, Shuai Liang, Yanfen Wang, Xia Huang

期刊论文

Identification of sources, characteristics and photochemical transformations of dissolved organic matter with EEM-PARAFAC

期刊论文

A chemometric analysis on the fluorescent dissolved organic matter in a full-scale sequencing batch reactor for municipal wastewater treatment

Chen Qian, Wei Chen, Wei-Hua Li, Han-Qing Yu

期刊论文

Interactions between metal ions and the biopolymer in activated sludge: quantification and effects of system pH value

Yun Zhou, Siqing Xia, Binh T. Nguyen, Min Long, Jiao Zhang, Zhiqiang Zhang

期刊论文

Investigation of fluorescence characterization and electrochemical behavior on the catalysts of nanosized Pt-Rh/γ-Al

Chang-Mao HUNG, Wen-Liang LAI, Jane-Li LIN

期刊论文

Chemical identification and genotoxicity analysis of petrochemical industrial wastewater

Jing ZHANG, Shigong WANG, Can WANG, Hongying HU

期刊论文

Characterization of the dissolved organic matter in sewage effluent of sequence batch reactor: the impact of carbon source

Jin GUO, Feng SHENG, Jianhua GUO, Xiong YANG, Mintao MA, Yongzhen PENG

期刊论文

Approximation of structural damping and input excitation force

Mohammad SALAVATI

期刊论文

Decellularized extracellular matrix mediates tissue construction and regeneration

期刊论文

同步发电机励磁系统中PWM控制的仿真研究

贾贵玺,徐伟,郭宝钥,张臣堂

期刊论文

Perspective of mixed matrix membranes for carbon capture

Shinji Kanehashi, Colin A. Scholes

期刊论文

一种基于子带激励替换的窄带语音水印算法

Wei LIU, Ai-qun HU

期刊论文

A new prediction method of industrial atmospheric pollutant emission intensity based on pollutant emission

期刊论文

Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated

期刊论文

A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

期刊论文