资源类型

期刊论文 498

会议视频 6

年份

2024 2

2023 44

2022 64

2021 55

2020 38

2019 39

2018 41

2017 26

2016 21

2015 21

2014 15

2013 11

2012 8

2011 12

2010 22

2009 14

2008 16

2007 21

2006 3

2005 4

展开 ︾

关键词

中国 2

二氧化碳 2

交通 2

医学 2

协调发展 2

反渗透 2

发展 2

多式联运 2

小麦 2

抗生素 2

&alpha 1

6016 铝合金 1

Heterodera glycines 1

Pm21 1

Pm40 1

ABC-F家族蛋白 1

Al2O3-MxOy 1

BSP) 1

DX桩 1

展开 ︾

检索范围:

排序: 展示方式:

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layer

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

《能源前沿(英文)》 2023年 第17卷 第1期   页码 123-133 doi: 10.1007/s11708-022-0849-1

摘要: High cost has undoubtedly become the biggest obstacle to the commercialization of proton exchange membrane fuel cells (PEMFCs), in which Pt-based catalysts employed in the cathodic catalyst layer (CCL) account for the major portion of the cost. Although non-precious metal catalysts (NPMCs) show appreciable activity and stability in the oxygen reduction reaction (ORR), the performance of fuel cells based on NPMCs remains unsatisfactory compared to those using Pt-based CCL. Therefore, most studies on NPMC-based fuel cells focus on developing highly active catalysts rather than facilitating oxygen transport. In this work, the oxygen transport behavior in CCLs based on highly active Fe-N-C catalysts is comprehensively explored through the elaborate design of two types of membrane electrode structures, one containing low-Pt-based CCL and NPMC-based dummy catalyst layer (DCL) and the other containing only the NPMC-based CCL. Using Zn-N-C based DCLs of different thickness, the bulk oxygen transport resistance at the unit thickness in NPMC-based CCL was quantified via the limiting current method combined with linear fitting analysis. Then, the local and bulk resistances in NPMC-based CCLs were quantified via the limiting current method and scanning electron microscopy, respectively. Results show that the ratios of local and bulk oxygen transport resistances in NPMC-based CCL are 80% and 20%, respectively, and that an enhancement of local oxygen transport is critical to greatly improve the performance of NPMC-based PEMFCs. Furthermore, the activity of active sites per unit in NPMC-based CCLs was determined to be lower than that in the Pt-based CCL, thus explaining worse cell performance of NPMC-based membrane electrode assemblys (MEAs). It is believed that the development of NPMC-based PEMFCs should proceed not only through the design of catalysts with higher activity but also through the improvement of oxygen transport in the CCL.

关键词: proton exchange membrane fuel cells (PEMFCs)     non-precious metal catalyst (NPMC)     cathode catalyst layer (CCL)     local and bulk oxygen transport resistance    

Understand the local and regional contributions on air pollution from the view of human health impacts

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1382-2

摘要:

• PM2.5-related deaths were estimated to be 227 thousand in BTH & surrounding regions.

关键词: PM2.5     Regional transport     Local emissions     Health impact     Environmental inequality    

Transport of antibiotic resistance plasmids in porous media and the influence of surfactants

Peipei Chen, Chaoqi Chen, Xiqing Li

《环境科学与工程前沿(英文)》 2018年 第12卷 第2期 doi: 10.1007/s11783-017-0986-7

摘要: Transport of engineered antibiotic resistance plasmids in porous media has been reported to potentially cause significant spreading of antibiotic resistance in the environment. In this work, transport of an indigenous resistance plasmid pK5 in porous media was investigated through packed column experiments. At identical ionic strengths in CaCl solutions, the breakthroughs of pK5 from soil columns were very close to those from quartz sand columns, indicating that transport of pK5 in quartz sand and soil was similar. A similarity in transport behavior was also found between pK5 and an engineered plasmid pBR322 that has approximately the same number of base pairs as pK5. The influence of surfactants, a major group of constituents in soil solutions, was examined using an engineered plasmid pcDNA3.1(+)/myc-His A. The impact of an anionic surfactant, sodium dodecyl sulfate (SDS), was negligible at concentrations up to 200 mg·L . Cetyltrimethyl ammonium bromide (CTAB), a cationic surfactant, was found to significantly enhance plasmid adsorption at high concentrations. However, at environmentally relevant concentrations (<1 mg·L ), the effect of this surfactant was also minimal. The negligible impact of surfactants and the similarity between the transport of engineered and indigenous plasmids indicate that under environmentally relevant conditions, indigenous plasmids in soil also have the potential to transport over long distances and lead to the spreading of antibiotic resistance.

关键词: Indigenous plasmid     Transport     Porous media     Surfactants    

Resistance of large caisson in floating transport considering the influence of air

Junjie ZHENG, Zongzhe LI, Dongan ZHAO, Qiang MA, Rongjun ZHANG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 331-338 doi: 10.1007/s11709-010-0085-3

摘要: This paper deals with the floating resistance of super large caisson by numerical simulation, and the influence of air resistance on the caisson, which is often ignored by previous researchers, is considered. The floating caisson of Taizhou Highway Bridge’s middle tower pier is investigated, and the software package FLUENT is used to simulate the floating process of large-scale rounded rectangular steel caisson. This simulation adopts the volume of fluid (VOF) model with water-air two-phase flow, which can take both the hydraulic resistance and air resistance into account. Subsequently, the analyses on hydraulic resistance and air resistance under different working conditions, such as different flow velocities and different draughts of water are performed, and the results are compared with those calculated by related empirical formula. The comparison shows that the air resistance takes up notable portion in the total resistance on the floating caisson, and the effect of air resistance on the safety of caisson should be paid sufficient attention to rather than be ignored.

关键词: large-scale caisson     numerical simulation     hydraulic resistance     air resistance    

Degradation of permeability resistance of high strength concrete after combustion

LI Min, QIAN Chunxiang, KAO Hongtao

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 281-287 doi: 10.1007/s11709-008-0031-9

摘要: To evaluate the remaining durability of concrete materials after combustion, the permeability of high strength concrete (HSC) after combustion was studied. The transport behavior of chloride ion, water and air in concrete after combustion and the effect of temperature, strength grade, and aggregation on the permeability of HSC after combustion are investigated by chloride ion permeability coefficient (), water permeability coefficient () and air permeability coefficient (). The experiment results show that all three permeability coefficients commendably reflect changes of permeability. The permeability coefficient increases with the evaluation temperature. After the same temperature, the permeability coefficient of HSC is lower than that of normal strength concrete (NSC). However, the degree of degradation of permeability coefficient of HSC is greater than that of NSC. The permeability resistance of HSC containing limestone is better than that of HSC containing basalt. Combining changes of compressive strength and permeability, the remaining durability of concrete materials after combustion is appropriately evaluated.

关键词: transport behavior     limestone     durability     permeability     HSC    

Local resistance of fluid flow across sudden contraction in small channels

Hang GUO, Ling WANG, Jian YU, Fang YE, Chongfang MA, Zhuo LI,

《能源前沿(英文)》 2010年 第4卷 第2期   页码 149-154 doi: 10.1007/s11708-009-0060-7

摘要: The pressure drop caused by flow area contraction in microchannels has been experimentally studied in this paper using the tiny gap pressure measurement method. The working fluid was deionized water at room temperature at near-atmospheric pressure. Three test sections with area ratios of 0.284 and 0.274 and at different tube diameter sizes were used. The experimental results show that the abrupt contraction coefficient decreases with the Reynolds number increasing, and it is much higher than that of conventional tubes in laminar flow. The widely-applied correlation =0.5(1−) could not predict the contraction coefficient of turbulent flow in the micro tubes. The decreases as the tube diameter increases. The transition from laminar to turbulent flow is not obvious when the diameter of the small tube is 0.32mm.

关键词: microchannels     pressure drop     abrupt contraction     loss coefficients    

Thermal transport in organic/inorganic composites

Bin LIU, Lan DONG, Qing XI, Xiangfan XU, Jun ZHOU, Baowen LI

《能源前沿(英文)》 2018年 第12卷 第1期   页码 72-86 doi: 10.1007/s11708-018-0526-6

摘要: Composite materials, which consist of organic and inorganic components, are widely used in various fields because of their excellent mechanical properties, resistance to corrosion, low-cost fabrication, etc. Thermal properties of organic/inorganic composites play a crucial role in some applications such as thermal interface materials for micro-electronic packaging, nano-porous materials for sensor development, thermal insulators for aerospace, and high-performance thermoelectric materials for power generation and refrigeration. In the past few years, many studies have been conducted to reveal the physical mechanism of thermal transport in organic/inorganic composite materials in order to stimulate their practical applications. In this paper, the theoretical and experimental progresses in this field are reviewed. Besides, main factors affecting the thermal conductivity of organic/inorganic composites are discussed, including the intrinsic properties of organic matrix and inorganic fillers, topological structure of composites, loading volume fraction, and the interfacial thermal resistance between fillers and organic matrix.

关键词: thermal conductivity     organic/inorganic composites     effective medium theory     thermal percolation theory     interfacial thermal resistance    

大块非晶合金:历史发展和当前研究 Review

Akihisa Inoue

《工程(英文)》 2015年 第1卷 第2期   页码 185-191 doi: 10.15302/J-ENG-2015038

摘要:

通过关注采用传统模型铸造方法合成首批大块非晶合金的触发点,本文论述了大块非晶合金的当前研究进展情况。该综述涵盖大块非晶合金的背景、发现、特点和应用以及近期与其相关的研究主题。由于其性质独特,非晶形成能力高且成本低廉,大块非晶合金 ( 尤其是铁基大块非晶合金) 的应用范围正逐步扩大。在不久的将来,大块非晶合金在工程领域的重要性预计将稳步提高,预期将上述创新型金属材料用于基础科学研究的热度仍将持续。

关键词: 大块非晶合金,模型铸造,金属材料,结构弛豫    

聚酰胺反渗透膜中水传递阻力的分子模拟——界面阻力和内部阻力 Article

宋阳, 魏明杰, 徐放, 汪勇

《工程(英文)》 2020年 第6卷 第5期   页码 577-584 doi: 10.1016/j.eng.2020.03.008

摘要:

在分子水平上理解水分子在聚酰胺(PA)反渗透(RO)膜中的传递阻力对于这些膜的设计、制备和应用具有非常重要的指导意义。本文通过分子模拟来计算总传递阻力,并将其分成两部分——内部阻力和界面阻力。内部阻力取决于PA层的厚度,而界面阻力则不然。基于5 nm 厚的PA层的模拟显示界面阻力对总阻力的贡献率很大(> 62%)。然而,现实世界中,对于具有200 nm PA层的RO膜,界面阻力起次要作用,其贡献率低于10%。这表明,当使用典型方法估算RO膜的传递阻力时,存在不准确的风险,因为该方法简单地将5 nm厚的PA层的总阻力进行倍增,使得界面阻力被错误放大。此外,界面阻力和内部阻力均取决于PA层的化学性质。我们的模拟显示,减少PA层中剩余羧基的数量会导致内部阻力降低,因此,可以在不牺牲离子截留的情况下改善水的渗透性,这与实验结果高度吻合。

关键词: 传递阻力     反渗透     非平衡分子动力学     水分子亲水性     建模    

Region-gridding recycling of bulk organic waste: Emerging views based on coordinated urban and rural

Wenbing Tan, Dongyu Cui, Xiaohui Zhang, Beidou Xi

《环境科学与工程前沿(英文)》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1291-4

摘要: Abstract Bulk organic waste (BOW) has a large output in China. The improper disposal of BOW will not only bring serious environmental pollution, but also cause waste of biomass resources. The viewpoint proposes a region-gridding recycling management system of BOW that highlights the coordinated development of environmental, agricultural and energy elements in urban and rural areas. The viewpoint aims to drive the upstream and downstream industrial chains of BOW treatments, avoid the repeated construction of resource facilities, guide the upgrading of resource-based technologies, promote the professionalization of farmers, and thus built the high-quality modern agricultural recycling industrial park based on system management.

关键词: Bulk organic waste     Recycling     Urban-rural coordination     Management system    

Elimination of antibiotic resistance genes and control of horizontal transfer risk by UV-based treatment

Virender K. Sharma, Xin Yu, Thomas J. McDonald, Chetan Jinadatha, Dionysios D. Dionysiou, Mingbao Feng

《环境科学与工程前沿(英文)》 2019年 第13卷 第3期 doi: 10.1007/s11783-019-1122-7

摘要:

Antibiotic-resistant bacteria and antibiotic resistance genes are in water bodies.

UV/chlorination method is better to remove ARGs than UV or chlorination alone.

Research on UV/hydrogen peroxide to eliminate ARGs is forthcoming.

UV-based photocatalytic processes are effective to degrade ARGs.

关键词: Antibiotic resistance bacteria     Advanced oxidation processes     Disinfection     Reactive chlorine species     Sulfate radicals     Reactive oxygen species    

Changes in bulk soil affect the disease-suppressive rhizosphere microbiome against Fusarium wilt disease

Lin FU, Wu XIONG, Francisco DINI-ANDREOTE, Beibei WANG, Chengyuan TAO, Yunze RUAN, Zongzhuan SHEN, Rong LI, Qirong SHEN

《农业科学与工程前沿(英文)》 2020年 第7卷 第3期   页码 307-316 doi: 10.15302/J-FASE-2020328

摘要:

Harnessing disease-suppressive microbiomes constitutes a promising strategy for optimizing plant growth. However, relatively little information is available about the relationship between bulk and rhizosphere soil microbiomes. Here, the assembly of banana bulk soil and rhizosphere microbiomes was investigated in a monoculture system consisting of bio-organic (BIO) and organic management practices. Applying BIO practice in newly reclaimed fields resulted in a high-efficiency biocontrol rate, thus providing a promising strategy for pre-control of Fusarium wilt disease. The soil microbiota was further characterized by MiSeq sequencing and quantitative PCR. The results indicate that disease suppression was mediated by the structure of a suppressive rhizosphere microbiome with respect to distinct community composition, diversity and abundance. Overall microbiome suppressiveness was primarily related to a particular set of enriched bacterial taxa affiliated with s, , , , and . Finally, structural equation modeling was used to show that the changes in bulk soil bacterial community determined its induced rhizosphere bacterial community, which serves as an important and direct factor in restraining the pathogen. Collectively, this study provides an integrative approach to disentangle the biological basis of disease-suppressive microbiomes in the context of agricultural practice and soil management.

关键词: agricultural practice     bulk soil     disease suppression     rhizosphere ecology    

Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

《农业科学与工程前沿(英文)》 2017年 第4卷 第1期   页码 97-105 doi: 10.15302/J-FASE-2016115

摘要: A bulk polymerization monomer dehydro- abietic acid-(2-acryloyloxy-ethoxy)-ethyl ester (DHA-DG-AC) was synthesized from dehydroabietic acid (DHA). The chemical structure of DHA-DG-AC was characterized by H NMR, C NMR, MS and FT-IR. The kinetics of the bulk polymerization of DHA-DG-AC was investigated by Differential Scanning Calorimeter (DSC). Two kinds of kinetic model (nth-order model and autocatalytic model) were used to investigate the polymerization process. The results showed that the experimental DSC curves were consistent with the computational data generated by the autocatalytic kinetic model, and the value of was 95.73 kJ·mol .

关键词: dehydroabietic acid     bulk polymerization     kinetics     autocatalytic kinetic model    

High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要: We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词: second-order maximum entropy     local maximum entropy     second- and fourth-order phase-field models     B-spline    

Local uncorrelated local discriminant embedding for face recognition

Xiao-hu MA,Meng YANG,Zhao ZHANG

《信息与电子工程前沿(英文)》 2016年 第17卷 第3期   页码 212-223 doi: 10.1631/FITEE.1500255

摘要: The feature extraction algorithm plays an important role in face recognition. However, the extracted features also have overlapping discriminant information. A property of the statistical uncorrelated criterion is that it eliminates the redundancy among the extracted discriminant features, while many algorithms generally ignore this property. In this paper, we introduce a novel feature extraction method called local uncorrelated local discriminant embedding (LULDE). The proposed approach can be seen as an extension of a local discriminant embedding (LDE) framework in three ways. First, a new local statistical uncorrelated criterion is proposed, which effectively captures the local information of interclass and intraclass. Second, we reconstruct the affinity matrices of an intrinsic graph and a penalty graph, which are mentioned in LDE to enhance the discriminant property. Finally, it overcomes the small-sample-size problem without using principal component analysis to preprocess the original data, which avoids losing some discriminant information. Experimental results on Yale, ORL, Extended Yale B, and FERET databases demonstrate that LULDE outperforms LDE and other representative uncorrelated feature extraction methods.

关键词: Feature extraction     Local discriminant embedding     Local uncorrelated criterion     Face recognition    

标题 作者 时间 类型 操作

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layer

Shiqu CHEN, Silei XIANG, Zehao TAN, Huiyuan LI, Xiaohui YAN, Jiewei YIN, Shuiyun SHEN, Junliang ZHANG

期刊论文

Understand the local and regional contributions on air pollution from the view of human health impacts

期刊论文

Transport of antibiotic resistance plasmids in porous media and the influence of surfactants

Peipei Chen, Chaoqi Chen, Xiqing Li

期刊论文

Resistance of large caisson in floating transport considering the influence of air

Junjie ZHENG, Zongzhe LI, Dongan ZHAO, Qiang MA, Rongjun ZHANG,

期刊论文

Degradation of permeability resistance of high strength concrete after combustion

LI Min, QIAN Chunxiang, KAO Hongtao

期刊论文

Local resistance of fluid flow across sudden contraction in small channels

Hang GUO, Ling WANG, Jian YU, Fang YE, Chongfang MA, Zhuo LI,

期刊论文

Thermal transport in organic/inorganic composites

Bin LIU, Lan DONG, Qing XI, Xiangfan XU, Jun ZHOU, Baowen LI

期刊论文

大块非晶合金:历史发展和当前研究

Akihisa Inoue

期刊论文

聚酰胺反渗透膜中水传递阻力的分子模拟——界面阻力和内部阻力

宋阳, 魏明杰, 徐放, 汪勇

期刊论文

Region-gridding recycling of bulk organic waste: Emerging views based on coordinated urban and rural

Wenbing Tan, Dongyu Cui, Xiaohui Zhang, Beidou Xi

期刊论文

Elimination of antibiotic resistance genes and control of horizontal transfer risk by UV-based treatment

Virender K. Sharma, Xin Yu, Thomas J. McDonald, Chetan Jinadatha, Dionysios D. Dionysiou, Mingbao Feng

期刊论文

Changes in bulk soil affect the disease-suppressive rhizosphere microbiome against Fusarium wilt disease

Lin FU, Wu XIONG, Francisco DINI-ANDREOTE, Beibei WANG, Chengyuan TAO, Yunze RUAN, Zongzhuan SHEN, Rong LI, Qirong SHEN

期刊论文

Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

期刊论文

High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

期刊论文

Local uncorrelated local discriminant embedding for face recognition

Xiao-hu MA,Meng YANG,Zhao ZHANG

期刊论文