资源类型

期刊论文 812

会议视频 32

会议信息 2

年份

2024 5

2023 67

2022 65

2021 87

2020 47

2019 37

2018 47

2017 31

2016 34

2015 37

2014 29

2013 34

2012 29

2011 35

2010 36

2009 47

2008 44

2007 39

2006 16

2005 8

展开 ︾

关键词

钢结构 8

建筑科学 7

三峡工程 3

优化设计 3

碳中和 3

耐久性 3

飞机结构 3

DSM（设计结构矩阵） 2

Quantitative structure 2

imge analysis 2

stereology 2

产业结构 2

人工智能 2

可持续发展 2

城镇建设 2

数值模拟 2

机器学习 2

机械结构 2

疲劳寿命 2

展开 ︾

检索范围：

排序： 展示方式：

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance

《化学科学与工程前沿（英文）》 2022年 第16卷 第4期   页码 484-497 doi: 10.1007/s11705-021-2074-6

摘要： The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process. The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method, and the morphology and lamellar structure were examined carefully. Several properties of mechanical, thermal and tribological responses of epoxy nanocomposites were performed. It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix, and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected. In addition, friction coefficient and wear rate were increased first and then decreased along with the particle content, and showed the lowest values at a mass fraction of 5%. Nevertheless, the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin (EP) nanocomposites. This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.

关键词： nickel phyllosilicate     flow-like structure     mechanical property     thermal stability     tribological performance    

HTML PDF 收藏

Damage detection in beam-like structures using static shear energy redistribution

《结构与土木工程前沿（英文）》 2022年 第16卷 第12期   页码 1552-1564 doi: 10.1007/s11709-022-0903-4

摘要： In this study, a static shear energy algorithm is presented for the damage assessment of beam-like structures. According to the energy release principle, the strain energy of a damaged element suddenly changes when structural damage occurs. Therefore, the change in the static shear energy is employed to determine the damage locations in beam-like structures. The static shear energy is derived from the spectral factorization of the elementary stiffness matrix and structural deflection variation. The advantage of using shear energy as opposed to total energy is that only a few deflection data points of the beam structure are required during the process of damage identification. Another advantage of the proposed approach is that damage detection can be performed without establishing a structural finite-element model in advance. The proposed technique is first validated using a numerical example with single, multiple, and adjacent damage scenarios. A channel steel beam and rectangular concrete beam are employed as experimental cases to further verify the proposed approach. The results of the simulation and experiment examples indicate that the proposed algorithm provides a simple and effective method for defect localization in beam-like structures.

关键词： damage detection     beam structure     strain energy     static displacement variation     energy damage index    

HTML PDF 收藏

URANS simulation of the turbulent flow in tight lattice bundle

Yiqi YU, Yanhua YANG

《能源前沿（英文）》 2011年 第5卷 第4期   页码 404-411 doi: 10.1007/s11708-011-0165-7

摘要： The flow structure in tight lattice is still of great interest to nuclear industry. An accurate prediction of flow parameter in subchannels of tight lattice is likable. Unsteady Reynolds averaged Navier Stokes (URANS) is a promising approach to achieve this goal. The implementation of URANS approach will be validated by comparing computational results with the experimental data of Krauss. In this paper, the turbulent flow with different Reynolds number (5000–215000) and different pitch-to-diameter( / ) (1.005–1.2) are simulated with computational fluid dynamics (CFD) code CFX12. The effects of the Reynolds number and the bundle geometry ( / ) on wall shear stress, turbulent kinetic energy, turbulent mixing and large scale coherent structure in tight lattice are analyzed in details. It is hoped that the present work will contribute to the understanding of these important flow phenomena and facilitate the prediction and design of rod bundles.

关键词： tight rod bundle     flow structure     unsteady Reynolds averaged Navier Stokes (URANS)    

HTML PDF 收藏

Estimation of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitativestructure-property relationship

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

《环境科学与工程前沿（英文）》 2014年 第8卷 第5期   页码 683-692 doi: 10.1007/s11783-014-0680-y

摘要： In this paper the photolysis half-lives of the model dyes in water solutions and under ultraviolet (UV) radiation were determined by using a continuous-flow spectrophotometric method. A quantitative structure-property relationship (QSPR) study was carried out using 21 descriptors based on different chemometric tools including stepwise multiple linear regression (MLR) and partial least squares (PLS) for the prediction of the photolysis half-life ( ) of dyes. For the selection of test set compounds, a K-means clustering technique was used to classify the entire data set, so that all clusters were properly represented in both training and test sets. The QSPR results obtained with these models show that in MLR-derived model, photolysis half-lives of dyes depended strongly on energy of the highest occupied molecular orbital ( ), largest electron density of an atom in the molecule ( ) and lipophilicity (log ). While in the model derived from PLS, besides aforementioned and descriptors, the molecular surface area ( ), molecular weight ( ), electronegativity ( ), energy of the second highest occupied molecular orbital ( ) and dipole moment ( ) had dominant effects on logt values of dyes. These were applicable for all classes of studied dyes (including monoazo, disazo, oxazine, sulfonephthaleins and derivatives of fluorescein). The results were also assessed for their consistency with findings from other similar studies.

关键词： dye     photolysis half-life     quantitative structure-property relationship     continuous-flow     stepwise multiple linear regression     partial least squares    

HTML PDF 收藏

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 68-71 doi: 10.1007/s11705-007-0014-8

摘要： The association and properties of multi-block like copolymers (TP) of acrylamide (AM) and acrylic acid (AA) prepared by template copolymerization in aqueous solution were studied. The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers (CP) obtained by copolymerization in the absence of template. Decreasing the value of pH or adding Ca ion to the copolymer solution will make phase separation occur. The TEM images demonstrated that the phase separation caused by Ca ion was due to the formation of extensively intermolecular cross-linking. With the increase of the pH value of copolymer solution, the changes of the solution viscosity was similar with that of homopolyacrylic acid, which originally increased and then decreased. But the increase range of template copolymer was higher than that of homopolyacrylic acid. TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.

关键词： aqueous solution     homopolyacrylic     copolymer solution     significant structure     presence    

HTML PDF 收藏

Decontamination efficiency and root structure change in the plant-intercropping model in vertical-flow

Yonghua CHEN, Xiaofu WU, Mingli CHEN, Kelin LI, Jing PENG, Peng ZHAN

《环境科学与工程前沿（英文）》 2013年 第7卷 第6期   页码 906-912 doi: 10.1007/s11783-013-0579-z

摘要： Subtropical climatic conditions can contribute to the death of the aerial parts of constructed wetland plants in winter. This presents a barrier to the widespread application of constructed wetland and is an issue that urgently needs to be solved. Three contrasting experiments, the plant-intercropping model (A), the warm-seasonal plant model (B), and the non-plant model (C), were studied in terms of their efficiency in removing pollutants, and the change in root structure of plants in the plant-intercropping model within the vertical-flow constructed wetlands. The results indicate that model A was able to solve the aforementioned problem. Overall, average removal rates of three pollutants (COD , total nitrogen (TN) and total phosphorous (TP)) using model A were significantly higher than those obtained using models B and C ( <0.01). Moreover, no significant differences in removal rates of the three pollutants were detected between A and B during the higher temperature part of the year ( >0.05). Conversely, removal rates of the three pollutants were found to be significantly higher using model A than those observed using model B during the lower temperature part of the year ( <0.01). Furthermore, the morphologies and internal structures of plant roots further demonstrate that numerous white roots, whose distribution in soil was generally shallow, extend further under model A. The roots of these aquatic plants have an aerenchyma structure composed of parenchyma cells, therefore, roots of the cold-seasonal plants with major growth advantages used in A were capable of creating a more favorable vertical-flow constructed wetlands media-microenvironment. In conclusion, the plant-intercropping model (A) is more suitable for use in the cold environment experienced by constructed wetland during winter.

关键词： vertical-flow constructed wetlands     plant intercropping model     warm seasonal plant model    

HTML PDF 收藏

Image analyses for video-based remote structure vibration monitoring system

Yang YANG,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年 第10卷 第1期   页码 12-21 doi: 10.1007/s11709-016-0313-6

摘要： Video-based vibration measurement is a cost-effective way for remote monitoring the health conditions of transportation and other civil structures, especially for situations where accessibility is restricted and does not allow installation of conventional monitoring devices. Besides, video-based system is global measurement. The technical basis of video-based remote vibration measurement system is digital image analysis. Comparison of the images allow the field of motion to be accurately delineated. Such information is important to understand the structure behaviors including the motion and strain distribution. This paper presents system and analyses to monitor the vibration velocity and displacement field. The performance is demonstrated on a testbed of model building. Three different methods (i.e., frame difference method, particle image velocimetry, and optical Flow Method) are utilized to analyze the image sequences to extract the feature of motion. The Performance is validated using accelerometer data. The results indicate that all three methods can estimate the velocity field of the model building, although the results can be affected by factors such as background noise and environmental interference. Optical flow method achieved the best performance among these three methods studied. With further refinement of system hardware and image processing software, it will be developed into a remote video based monitoring system for structural health monitoring of transportation infrastructure to assist the diagnoses of its health conditions.

关键词： structure health monitoring     velocity estimation     frame difference     PIV     optical-flow method    

HTML PDF 收藏

β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

《能源前沿（英文）》 2017年 第11卷 第3期   页码 401-409 doi: 10.1007/s11708-017-0496-0

摘要： As part of an effort to build a prototype flow battery system using a nano-suspension containing β-Ni(OH) nanoparticles as the cathode material, nano-sized β-Ni(OH) particles with well-controlled particle size and morphology were synthesized via the one-step precipitation of a NiCl precursor. The composition and morphology of the nanoparticles were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The XRD patterns confirmed that β-Ni(OH) was successfully synthesized, while SEM results showed that the particle sizes range from 70 to 150 nm. To ensure that Ni(OH) could be employed in the nano-suspension flow battery, the electrochemical performance of the synthesized β-Ni(OH) was initially tested in pouch cells through charge/discharge cycling. The phase transformations occurring during charge/discharge were investigated using X-ray absorption spectroscopy to obtain the shift in the oxidation state of Ni (X-ray adsorption near edge structure, XANES) and the distances between Ni and surrounding atoms in charged and discharged states (extended X-ray absorption fine structure, EXAFS). XANES results indicated that the electrode in the discharged state was a mixture of phases because the edge position did not shift back completely. XAFS results further proved that the discharge capacity was provided by β-NiOOH and the ratio between β-Ni(OH) and g-NiOOH in the electrode in the discharged state was 71:29. Preliminary nano-suspension tests in a lab-scale cell were conducted to understand the behavior of the nano-suspension during charge/discharge cycling and to optimize the operating conditions.

关键词： nano-suspension flow battery     β-Ni(OH)2     scanning electronic microscopy (SEM)     X-ray diffraction (XRD)     X-ray adsorption near edge structure (XANES)     extended X-ray absorption fine structure (EXAFS)    

HTML PDF 收藏

Distinct immune escape and microenvironment between RG-like and pri-OPC-like glioma revealed by single-cell

《医学前沿（英文）》 doi: 10.1007/s11684-023-1017-7

摘要： The association of neurogenesis and gliogenesis with glioma remains unclear. By conducting single-cell RNA-seq analyses on 26 gliomas, we reported their classification into primitive oligodendrocyte precursor cell (pri-OPC)-like and radial glia (RG)-like tumors and validated it in a public cohort and TCGA glioma. The RG-like tumors exhibited wild-type isocitrate dehydrogenase and tended to carry EGFR mutations, and the pri-OPC-like ones were prone to carrying TP53 mutations. Tumor subclones only in pri-OPC-like tumors showed substantially down-regulated MHC-I genes, suggesting their distinct immune evasion programs. Furthermore, the two subgroups appeared to extensively modulate glioma-infiltrating lymphocytes in distinct manners. Some specific genes not expressed in normal immune cells were found in glioma-infiltrating lymphocytes. For example, glial/glioma stem cell markers OLIG1/PTPRZ1 and B cell-specific receptors IGLC2/IGKC were expressed in pri-OPC-like and RG-like glioma-infiltrating lymphocytes, respectively. Their expression was positively correlated with those of immune checkpoint genes (e.g., LGALS3) and poor survivals as validated by the increased expression of LGALS3 upon IGKC overexpression in Jurkat cells. This finding indicated a potential inhibitory role in tumor-infiltrating lymphocytes and could provide a new way of cancer immune evasion.

关键词： single-cell RNA-seq     glioma     radial glia     primitive oligodendrocyte precursor cell     immune escape    

HTML PDF 收藏

Toll-like receptors in innate immunity and infectious diseases

Min-Hao WU, Ping ZHANG, Xi HUANG,

《医学前沿（英文）》 2010年 第4卷 第4期   页码 385-393 doi: 10.1007/s11684-010-0600-x

摘要： The protective ability of host defense system is largely dependent on germ-line encoded pattern-recognition receptors (PRRs). These PRRs respond to a variety of exogenous pathogens or endogenous danger signals, by recognizing some highly conserved structures such as pathogen-associated molecular patterns (PAMPs) and danger/damage associated molecular patterns (DAMPs). The most studied PRRs are Toll-like receptors (TLRs). Activation of TLRs triggers production of inflammatory cytokines and type I interferons (IFNs) via myeloid differentiation primary response gene 88 (MyD88)-dependent or-independent signaling respectively, thereby modulating innate and adaptive immunity, as well as inflammatory responses. This review introduces the classification, structure, and specific ligands of TLRs, and focuses on their signal pathways and biological activities, as well as clinical relevance. These studies of TLRs in the innate immune system have implications for the prevention and treatment of a variety of infectious diseases, including tuberculosis (TB), microbial keratitis, and hepatitis B and C.

关键词： Toll-like receptors     innate immunity     infectious disease     inflammation    

HTML PDF 收藏

Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 127-134 doi: 10.1007/s11705-008-0033-0

摘要： A series of “guava-like” silica/polyacrylate nanocomposite particles with close silica content and different grafting degrees were prepared via mini-emulsion polymerization using 3-(trimethoxysilyl)propyl methacrylate (TSPM) modified silica/acrylate dispersion. The silica/polyacrylate composite particles were melt-mixed with unfilled polyacrylate (PA) resin to prepare corresponding silica/polyacrylate molded composites and the dispersion mechanism of these silica particles from the “guava-like” composite particles into polyacrylate matrix was studied. It was calculated that about 110 silica particles were accumulated in the bulk of every silica/polyacrylate composite latex particle. Both the solubility tests of silica/polyacrylate composite latex particles in tetrahydrofuran (THF) and the section transmission electron microscope (TEM) micrographs of silica/polyacrylate molded composites indicated that the grafting degree of silica particles played a crucial role in the dispersion of silica/polyacrylate composite particles into the polyacrylate matrix. When the grafting degree of polyacrylate onto silica was in a moderate range (ca. 20%–70%), almost all of silica particles in these “guava-like” composite particles were dispersed into the polyacrylate matrix in a primary-particle-level. However, at a lower grafting degree, massive silica aggregations were found in molded composites because of the lack of steric protection. At a greater grafting degree (i.e., 200%), a cross-linked network was formed in the silica/polyacrylate composite particles, which prevented the dispersion of composite particles in THF and polyacrylate matrix as primary particles.

关键词： silica/polyacrylate composite     cross-linked network     –70     guava-like     TEM    

HTML PDF 收藏

Layer-like FAU-type zeolites: A comparative view on different preparation routes

Bastian Reiprich, Tobias Weissenberger, Wilhelm Schwieger, Alexandra Inayat

《化学科学与工程前沿（英文）》 2020年 第14卷 第2期   页码 127-142 doi: 10.1007/s11705-019-1883-3

摘要： The creation of intergrown layer-like zeolite crystals is one route to form hierarchical zeolites. Faujasite-type (FAU-type) zeolites are among the industrially most important zeolites and the implementation of hierarchical porosity is a promising way to optimise their catalytic and adsorptive performance. After a short general survey into routes for the preparation of hierarchical pore systems in FAU, we will review the currently existing strategies for the synthesis of FAU with layer-like morphology. Those strategies are mainly based on the presence of morphology modifying agents in the synthesis mixture. However, a very recent approach is the synthesis of layer-like FAU-type zeolite crystals assembled in an intergrown manner in the absence of such additives, just by finely adjusting the crystallization temperature. This additive-free preparation route for layer-like FAU, which appears very attractive from an ecological as well as economic point of view, is highlighted in this review. Concluding, a comparison, including powder X-ray diffraction, scanning and transmission electron microscopy, nitrogen physisorption and elemental analysis, between conventional FAU and three layer-like FAU obtained by different synthesis routes was carried out to show the structural, morphological and textural differences and similarities of these materials.

关键词： FAU     hierarchical zeolite     layer-like morphology    

HTML PDF 收藏

Synthesis and characterization of well-defined comb-like branched polymers

LI Aixiang, LU Zaijun, LÜ Zijian

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 407-411 doi: 10.1007/s11705-008-0064-6

摘要： Well-defined comb-like branched polymers having one branch in each repeating unit have been successfully synthesized by the coupling reaction of living polystyrene (PS) and polyisoprene (PI) anions with 1, 1-diphenylethenyl (DPE) groups along PS backbone prepared via atom transfer radical polymerization (ATRP) of 4-vinylbenzyloxy benzophenone (Sc) followed by Wittig reaction. The resulting comb-like branched polymers were characterized by IR, H-NMR, gel permeation chromatography (GPC) and static light scattering (SLS) in detail. The effect of living chains and DPE group molar ratio on grafting efficiency was discussed. The results show the coupling reaction of living chains and DPE groups was highly effective, and the coupling efficiency can be controlled via the feed molar ratios of living chains and DPE groups. Moreover, the effect of molecular weights of backbone (PSe) and PSLi or PILi on grafting efficiency was also discussed. The results show that when excess living polymers were used, the almost quantitative grafting efficiency could be achieved.

关键词： grafting efficiency     polyisoprene     quantitative grafting     effective     molecular    

HTML PDF 收藏

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

《环境科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 483-495 doi: 10.1007/s11783-013-0595-z

摘要： A novel Ultrasonic Assisted Membrane Reduction (UAMR)-hydrothermal method was used to prepare flower-like Pt/CeO catalysts. The texture, physical/chemical properties, and reducibility of the flower-like Pt/CeO catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), N adsorption, and hydrogen temperature programmed reduction (H -TPR) techniques. The catalytic performance of the catalysts for treating automobile emission was studied relative to samples prepared by the conventional wetness impregnation method. The Pt/CeO catalysts fabricated by this novel method showed high specific surface area and metal dispersion, excellent three-way catalytic activity, and good thermal stability. The strong interaction between the Pt nanoparticles and CeO improved the thermal stability. The Ce ions were incorporated into the surfactant chains and the Pt nanoparticles were stabilized through an exchange reaction of the surface hydroxyl groups. The SEM results demonstrated that the Pt/CeO catalysts had a typical three-dimensional (3D) hierarchical porous structure, which was favorable for surface reaction and enhanced the exposure degree of the Pt nanoparticles. In brief, the flower-like Pt/CeO catalysts prepared by UAMR-hydrothermal method exhibited a higher Pt metal dispersion, smaller particle size, better three-way catalytic activity, and improved thermal stability versus conventional materials.

关键词： three-way catalyst     flower-like     Ultrasonic Assisted Membrane Reduction (UAMR)     Pt nanoparticles    

HTML PDF 收藏

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

《环境科学与工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1804-7

摘要：

● Cu-C-MSNs are developed via a co-doping step of Cu with L(+)-ascorbic acid.

关键词： Cation-π structures     Polarization electric field     Fenton-like process     Contaminants cleavage    

HTML PDF 收藏

标题 作者 时间 类型 操作

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance

期刊论文

Damage detection in beam-like structures using static shear energy redistribution

期刊论文

URANS simulation of the turbulent flow in tight lattice bundle

Yiqi YU, Yanhua YANG

期刊论文

Estimation of photolysis half-lives of dyes in a continuous-flow system with the aid of quantitativestructure-property relationship

Davoud BEIKNEJAD,Mohammad Javad CHAICHI

期刊论文

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template

ZHANG Yuxi, WU Feipeng, LI Miaozhen, WANG Erjian

期刊论文

Decontamination efficiency and root structure change in the plant-intercropping model in vertical-flow

Yonghua CHEN, Xiaofu WU, Mingli CHEN, Kelin LI, Jing PENG, Peng ZHAN

期刊论文

Image analyses for video-based remote structure vibration monitoring system

Yang YANG,Xiong (Bill) YU

期刊论文

β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

期刊论文

Distinct immune escape and microenvironment between RG-like and pri-OPC-like glioma revealed by single-cell

期刊论文

Toll-like receptors in innate immunity and infectious diseases

Min-Hao WU, Ping ZHANG, Xi HUANG,

期刊论文

Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

期刊论文

Layer-like FAU-type zeolites: A comparative view on different preparation routes

Bastian Reiprich, Tobias Weissenberger, Wilhelm Schwieger, Alexandra Inayat

期刊论文

Synthesis and characterization of well-defined comb-like branched polymers

LI Aixiang, LU Zaijun, LÜ Zijian

期刊论文

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

期刊论文

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

期刊论文