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低温铝电解 2

惰性阳极 2

SiC绝缘侧壁 1

乳液共聚合 1

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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 1

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Experimental and modeling studies on installation of arc sprayed Zn anodes for protection of reinforced concrete structures

Xianming SHI

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 1-11 doi: 10.1007/s11709-016-0312-7

摘要: Arc sprayed zinc (Zn) anode on concrete surfaces has been an emerging technology for protecting reinforced concrete structures from rebar corrosion in coastal environments. Many cathodic protection (CP) systems with arc sprayed Zn anodes will reach or exceed their design life in the near future and thus may function improperly or insufficiently, making it necessary to replace the aged anodes. However, prior to this study, little was known about the most effective profile for the concrete surface, for either new concrete or old concrete with existing Zn anodes removed. This work develops criteria to properly prepare the concrete surface before the application of new Zn anode. Experimental studies were conducted both in the laboratory and for a field structure in Oregon. Artificial neural network was used to achieve better understanding of the complex cause-and-effect relationships inherent in the Zn-mortar or Zn–concrete systems and was successful in finding meaningful, logical results from the bond strength data. The goal is to achieve strong initial bond strength of new Zn to concrete, which is essential for long-term performance of the CP system. The results from this case study suggest that it is necessary to adjust the anode removal and surface sandblasting based on the electrochemical age of the existing concrete. In all cases of sandblasting, minimize the exposure of large aggregates (e.g., those bigger than 19 mm in diameter).

关键词: arc sprayed Zn     anode replacement     reinforced concrete     bridge preservation     neural networks     surface profile    

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

《能源前沿(英文)》 2022年 第16卷 第5期   页码 852-861 doi: 10.1007/s11708-021-0811-7

摘要: Fuel starvation can occur and cause damage to the cell when proton exchange membrane fuel cells operate under complex working conditions. In this case, carbon corrosion occurs. Oxygen evolution reaction (OER) catalysts can alleviate carbon corrosion by introducing water electrolysis at a lower potential at the anode in fuel shortage. The mixture of hydrogen oxidation reaction (HOR) and unsupported OER catalyst not only reduces the electrolysis efficiency, but also influences the initial performance of the fuel cell. Herein, Ti4O7 supported IrOx is synthesized by utilizing the surfactant-assistant method and serves as reversal tolerant components in the anode. When the cell reverse time is less than 100 min, the cell voltage of the MEA added with IrOx/Ti4O7 has almost no attenuation. Besides, the MEA has a longer reversal time (530 min) than IrOx (75 min), showing an excellent reversal tolerance. The results of electron microscopy spectroscopy show that IrOx particles have a good dispersity on the surface of Ti4O7 and IrOx/Ti4O7 particles are uniformly dispersed on the anode catalytic layer. After the stability test, the Ti4O7 support has little decay, demonstrating a high electrochemical stability. IrOx/Ti4O7 with a high dispersity has a great potential to the application on the reversal tolerance anode of the fuel cell.

关键词: proton exchange membrane fuel cell (PEMFC)     fuel starvation     cell reverse     reversal tolerance anode     oxygen evolution reaction    

Effect of fly ash replacement level on the fracture behavior of concrete

Mahdi AREZOUMANDI, Jeffery S. VOLZ

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 411-418 doi: 10.1007/s11709-013-0228-4

摘要: The production of portland cement–the key ingredient in concrete–generates a significant amount of carbon dioxide. However, due to its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete’s contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. ?This study presents the results of an experimental investigation that evaluates effect of fly ash replacement level on the fracture energy of concrete. This study includes four mixes with 0%, 30%, 50%, and 70% fly ash as a cement replacement. This experimental program consisted of 32 fracture beams to study the fracture behavior of concrete. The experimental fracture energies were compared with the fracture energy provisions of different design codes and also different analytical equations. Furthermore, statistical data analyses (parametric and non-parametric) were performed to evaluate whether or not there is any statistically significant difference between the experimental fracture energies of different mixes. Results of these statistical tests show that the mix with higher level of fly ash replacement level has higher fracture energy.

关键词: concrete     fracture energy     fly ash    

Endosulfan residues and farmers’ replacement behaviors of endosulfan in the north-west inland cotton

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1803-8

摘要:

● The situation of endosulfan residues in cotton fields were assessed.

关键词: Cotton fields     Endosulfan residues     Farmers     KAP survey     Replacement behaviours    

Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

《能源前沿(英文)》 2023年 第17卷 第5期   页码 569-584 doi: 10.1007/s11708-023-0875-7

摘要: Lithium (Li) metal is believed to be the “Holy Grail” among all anode materials for next-generation Li-based batteries due to its high theoretical specific capacity (3860 mAh/g) and lowest redox potential (−3.04 V). Disappointingly, uncontrolled dendrite formation and “hostless” deposition impede its further development. It is well accepted that the construction of three-dimensional (3D) composite Li metal anode could tackle the above problems to some extent by reducing local current density and maintaining electrode volume during cycling. However, most strategies to build 3D composite Li metal anode require either electrodeposition or melt-infusion process. In spite of their effectiveness, these procedures bring multiple complex processing steps, high temperature, and harsh experimental conditions which cannot meet the actual production demand in consideration of cost and safety. Under this condition, a novel method to construct 3D composite anode via simple mechanical modification has been recently proposed which does not involve harsh conditions, fussy procedures, or fancy equipment. In this mini review, a systematic and in-depth investigation of this mechanical deformation technique to build 3D composite Li metal anode is provided. First, by summarizing a number of recent studies, different mechanical modification approaches are classified clearly according to their specific procedures. Then, the effect of each individual mechanical modification approach and its working mechanisms is reviewed. Afterwards, the merits and limits of different approaches are compared. Finally, a general summary and perspective on construction strategies for next-generation 3D composite Li anode are presented.

关键词: lithium (Li)-ion battery (LIB)     Li metal battery     three-dimensional (3D) composite Li metal anode     mechanical modification     reducing local current density    

The evolution of surgical and medical treatment of aortic root aneurysm

null

《医学前沿(英文)》 2014年 第8卷 第4期   页码 427-432 doi: 10.1007/s11684-014-0385-4

摘要:

Since first report of aortic root replacement in 1968, the surgical risk and long term outcome of patients with aortic root aneurysm have been continuously improving. In the last 30 years, the surgical approach is also evolving towards more valve conservation with prophylactical intervention at an earlier clinical stage. Translational research has also led to emerging surgical innovation and new drug therapy. Their efficacies are currently under vigorous clinical trials and evaluations.

关键词: aortic root aneurysm     aortic root replacement     valve sparing root replacement     personalised external aortic root support    

Algal biomass derived biochar anode for efficient extracellular electron uptake from

Yan-Shan Wang, Dao-Bo Li, Feng Zhang, Zhong-Hua Tong, Han-Qing Yu

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1072-5

摘要:

Algal biochar anode produced higher biocurrent compared with graphite plate anode.

Algal biochar exhibited stronger electrochemical response to redox mediators.

Algal biochar showed excellent adsorption to redox mediators.

关键词: Algal biochar     Anode material     Electrochemical activity     Extracellular electron transport     Waste resource utilization    

Preparation of biomass-derived carbon loaded with MnO as lithium-ion battery anode for improving its

《化学科学与工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11705-023-2376-y

摘要: Biomass-derived carbon materials for lithium-ion batteries emerge as one of the most promising anodes from sustainable perspective. However, improving the reversible capacity and cycling performance remains a long-standing challenge. By combining the benefits of K2CO3 activation and KMnO4 hydrothermal treatment, this work proposes a two-step activation method to load MnO2 charge transfer onto biomass-derived carbon (KAC@MnO2). Comprehensive analysis reveals that KAC@MnO2 has a micro-mesoporous coexistence structure and uniform surface distribution of MnO2, thus providing an improved electrochemical performance. Specifically, KAC@MnO2 exhibits an initial charge-discharge capacity of 847.3/1813.2 mAh·g–1 at 0.2 A·g–1, which is significantly higher than that of direct pyrolysis carbon and K2CO3 activated carbon, respectively. Furthermore, the KAC@MnO2 maintains a reversible capacity of 652.6 mAh·g–1 after 100 cycles. Even at a high current density of 1.0 A·g–1, KAC@MnO2 still exhibits excellent long-term cycling stability and maintains a stable reversible capacity of 306.7 mAh·g–1 after 500 cycles. Compared with reported biochar anode materials, the KAC@MnO2 prepared in this work shows superior reversible capacity and cycling performance. Additionally, the Li+ insertion and de-insertion mechanisms are verified by ex situ X-ray diffraction analysis during the charge-discharge process, helping us better understand the energy storage mechanism of KAC@MnO2.

关键词: biomass-derived carbon     MnO2     lithium-ion batteries     anode material     high reversible capacity    

term performance of recycled concrete beams with different water–cement ratio and recycled aggregate replacement

Jingwei YING; Feiming SU; Shuangren CHEN

《结构与土木工程前沿(英文)》 2022年 第16卷 第3期   页码 302-315 doi: 10.1007/s11709-022-0803-7

摘要: The purpose of this study is to reveal the service performance of recycled aggregate concrete (RAC) components for different values of water−cement ratio and replacement rate of recycled coarse aggregate (RCA). Generally, the concrete strength decreases with the increase of the replacement rate of RCA, in order to meet the strength requirements when changing the replacement rate of RCA, it is necessary to change the water−cement ratio at the same time. Therefore, the axial compressive strengths of prism with 25 mix proportions, the short-term mechanical properties and long-term deformation properties of reinforced concrete beams were tested respectively by changing water−cement ratio and RCA replacement rate. The bearing capacity and the strain nephogram of samples under different loads were obtained using the Digital Image Correlation (DIC) method, and a self-made gravity loading experimental device was used for long-term deformation investigation. Results showed that the damage pattern of RAC was the same as that of natural aggregate concrete (NAC), but the brittleness was more pronounced. The brittleness of concrete before failure can be reduced more effectively by adjusting the replacement rate of RCA than by adjusting the water−cement ratio. The water−cement ratio has an evident influence on the axial compressive strength and early creep of concrete, while the replacement rate of RCA has a remarkable effect on the long-term deformation of the concrete beams.

关键词: recycled concrete     beam     the replacement rate of recycled coarse aggregate     water–cement ratio     digital image correlation    

中国铝工业应用新型电极材料的研究与展望

邱竹贤

《中国工程科学》 2001年 第3卷 第5期   页码 50-54

摘要:

介绍了现代铝工业上新近开发研制的几种电极材料,涉及惰性阴极、惰性阳极、双极性电极等;还研制了低温电解质,使电解温度降低到800~900℃。如果惰性电极与低温电解质配合起来应用,则能够明显减少工业铝生产中的物料消耗,节省电能,增大电解槽生产能力,并改善环境状况,可望大幅度降低生产成本。

关键词: 惰性阳极     惰性阴极     SiC绝缘侧壁     低温铝电解    

Recycled glass replacement as fine aggregate in self-compacting concrete

Yasser SHARIFI, Mahmoud HOUSHIAR, Behnam AGHEBATI

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 419-428 doi: 10.1007/s11709-013-0224-8

摘要: With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal by replacement of waste glass with concrete composition materials. Due to differences in mixture design, placement and consolidation techniques, the strength and durability of Self Compacting Concrete (SCC) may be different than those of conventional concrete. Therefore, replacement of waste glass with fine aggregate in SCC should deeply be investigated compared to conventional concretes. The aim of the present study is to investigate the effect of glass replacement with fine aggregate on the SCC properties. In present study, fine aggregate has been replaced with waste glass in six different weight ratios ranging from 0% to 50%. Fresh results indicate that the flow-ability characteristics have been increased as the waste glass incorporated to paste volume. Nevertheless, compressive, flexural and splitting strengths of concrete containing waste glass have been shown to decrease when the content of waste glass is increased. The strength reduction of concrete in different glass replacement ratios is not remarkable, thus it can be produced SCC with waste glass as fine aggregate in a standard manner.

关键词: Self Compacting Concrete (SCC)     recycle glass     fine aggregate     fresh and hardened properties    

21世纪伊始铝电解工业的新进展

邱竹贤

《中国工程科学》 2003年 第5卷 第4期   页码 41-46

摘要:

21世纪伊始,法国500kA特大型预焙阳极电解槽,以及中国320 kA大型电解槽的出现,标志着铝电解工业的重要新进展。文章从理论上分析了大型电解槽的优越性,论述了减少电解槽的热损失系数,即减少按单位电量核算的热损失量,便是大型槽能够节省电能的理论基础;应用低温铝电解和惰性电极是铝电解工业今后的发展方向。

关键词: 铝电解工业     大型电解槽     低温铝电解     惰性阳极和惰性阴极    

Utilization of MSWI fly ash as partial cement or sand substitute with focus on cementing efficiency and health risk assessment

Lei Zheng, Xingbao Gao, Wei Wang, Zifu Li, Lingling Zhang, Shikun Cheng

《环境科学与工程前沿(英文)》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1184-6

摘要: Washed MSWI fly ash was used as partial cement or sand substitute. Sand replacing is beneficial for strength, while cement replacement reduces strength. Cementing efficiency factor and mortar pore structure explain the strength results. Health risk assessment was conducted for MSWI fly ash blended cement mortar. CR and HI contributed by different exposures and heavy metals were analyzed. The strength of cement substituted mortar decreases with the increase in fly ash amount, whereas the strength increases when the fly ash is blended as sand substitute. A mortar with highest strength (compressive strength= 30.2 Mpa; flexural strength= 7.0 Mpa) was obtained when the sand replacement ratio was 0.75%. The k value (cementing efficiency) of fly ash varied between 0.36 and 0.15 for the fly ash fraction in binder between 5% and 25%. The k values of fly ash used for sand replacement were all significantly above that used for cement substitution. The macropores assigned to the gaps between particles decreased when the fly ash was used as sand replacement, providing an explanation for the strength enhancement. The waste-extraction procedure (toxicity-sulphuric acid and nitric acid method (HJ/T 299-2007)) was used to evaluate metal leaching, indicating the reuse possibility of fly ash blended mortar. For the mortar with the mass ratio of fly ash to binder of 0.5%, the carcinogenic risks (CR) and non-carcinogenic hazard quotient (HQ) in sensitive scenario for blended mortar utilization were 9.66 × 10-7 and 0.06, respectively; these results were both lower than the threshold values, showing an acceptable health risk. The CR (9.89 × 10-5) and HQ (3.89) of the non-sensitive scenario for fly ash treatment exceeded the acceptable threshold values, indicating health risks to onsite workers. The main contributor to the carcinogenic and non-carcinogenic risk is Cr and Cd, respectively. The CR and HQ from inhalation was the main route of heavy metal exposure.

关键词: MSWI fly ash     Cementing efficiency     Health risk assessment of heavy metal     Sand replacement     Cement replacement    

left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve replacement

《医学前沿(英文)》 2021年 第15卷 第3期   页码 416-437 doi: 10.1007/s11684-021-0852-7

摘要: Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

关键词: surgical aortic valve replacement     trans-catheter aortic valve implantation     left ventricular hypertrophy and fibrosis     myocardial force-velocity relationship     His-Purkinje pacing     renin-angiotensin system inhibitors     coronary access impairment    

铝电解用Fe-Ni-Co-Al2O3金属陶瓷惰性阳极

邱竹贤,石忠宁,徐君莉

《中国工程科学》 2004年 第6卷 第8期   页码 35-39

摘要:

研制了一种新型铝电解金属陶瓷惰性阳极,阳极基体由Fe-Ni-CoAl2O3构成。在石墨坩埚中,960℃温度下,电解质中的氧化铝质量分数为6.0%,摩尔比为2.6;阳极电流密度为1.0 A/cm2,阳极尺寸大小为120 mm×80 mm×15 mm,石墨阴极尺寸大小为120 mm×40 mm×20 mm,通入的直流电为100~300 A,电解时间各为10 h;实验所得的电解铝产品纯度达到98%以上,杂质主要为Fe,Ni,Co;电解后的阳极外观尺寸无明显变化,阳极气体中氧气质量分数达到98%~99%。阳极的反电动势为2.45 V,比理论分解电压仅高出0.25 V证明该阳极为惰性阳极,在电解槽中进行的是Al2O3的分解反应。

关键词: 铝电解     惰性阳极     反电动势    

标题 作者 时间 类型 操作

Experimental and modeling studies on installation of arc sprayed Zn anodes for protection of reinforced concrete structures

Xianming SHI

期刊论文

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

期刊论文

Effect of fly ash replacement level on the fracture behavior of concrete

Mahdi AREZOUMANDI, Jeffery S. VOLZ

期刊论文

Endosulfan residues and farmers’ replacement behaviors of endosulfan in the north-west inland cotton

期刊论文

Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

期刊论文

The evolution of surgical and medical treatment of aortic root aneurysm

null

期刊论文

Algal biomass derived biochar anode for efficient extracellular electron uptake from

Yan-Shan Wang, Dao-Bo Li, Feng Zhang, Zhong-Hua Tong, Han-Qing Yu

期刊论文

Preparation of biomass-derived carbon loaded with MnO as lithium-ion battery anode for improving its

期刊论文

term performance of recycled concrete beams with different water–cement ratio and recycled aggregate replacement

Jingwei YING; Feiming SU; Shuangren CHEN

期刊论文

中国铝工业应用新型电极材料的研究与展望

邱竹贤

期刊论文

Recycled glass replacement as fine aggregate in self-compacting concrete

Yasser SHARIFI, Mahmoud HOUSHIAR, Behnam AGHEBATI

期刊论文

21世纪伊始铝电解工业的新进展

邱竹贤

期刊论文

Utilization of MSWI fly ash as partial cement or sand substitute with focus on cementing efficiency and health risk assessment

Lei Zheng, Xingbao Gao, Wei Wang, Zifu Li, Lingling Zhang, Shikun Cheng

期刊论文

left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve replacement

期刊论文

铝电解用Fe-Ni-Co-Al2O3金属陶瓷惰性阳极

邱竹贤,石忠宁,徐君莉

期刊论文