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RELAP5 1

事故工况 1

人体测量 1

全膝关节置换 1

冷却 1

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

医院中子照射器I型堆 1

哈龙 1

哈龙替代 1

基于族群的设计 1

增材制造 1

建议 1

战略 1

无偏溯源角；光栅干涉仪；六自由度测量；角度表达方法 1

更新费用 1

替代 1

替代物 1

气溶胶 1

气溶胶灭火剂 1

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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

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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

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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

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事故工况下医院中子照射器I型堆瞬态特性研究

朱磊,陈立新,江新标,赵柱民,周永茂

《中国工程科学》 2012年第14卷第8期页码 60-63

摘要：

采用RELAP5/SCDAP/MOD3.4程序对医院中子照射器I型堆（IHNI-1）在事故工况下的瞬态特性进行研究，对意外大反应性引入和池水丧失事故工况进行了计算和分析，计算结果表明：IHNI-1堆具有良好的固有安全性，在发生大反应性引入和池水丧失事故时，最终能够稳定在较低功率，确保反应堆安全。

关键词：医院中子照射器I型堆事故工况瞬态特性 RELAP5

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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

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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

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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

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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

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给水管道更新资金分配模型的研究

崔洪升,张宏伟,牛志广,傅玉芬

《中国工程科学》 2007年第9卷第9期页码 68-71

摘要：

以管道更新前后管网维护费用降低最大为目标，建立了考虑和不考虑异型管两种情况下的管道更新资金分配模型。实例验证了该模型能够在充分利用维护资金的前提下，最大限度地降低管网漏失损失，为供水管理部门合理使用资金、有效控制漏损和产销差率提供理论支持和决策指导

关键词：给水管道维护费用更新费用资金分配

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Punching shear behavior of recycled aggregate concrete slabs with and without steel fibres

Jianzhuang XIAO, Wan WANG, Zhengjiu ZHOU, Mathews M. TAWANA

《结构与土木工程前沿（英文）》 2019年第13卷第3期页码 725-740 doi: 10.1007/s11709-018-0510-6

摘要： A study on the punching shear behavior of 8 slabs with recycled aggregate concrete (RAC) was carried out. The two main factors considered were the recycled coarse aggregate (RCA) replacement percentage and the steel fibre volumetric ratio. The failure pattern, load-displacement curves, energy consumption and the punching shear capacity of the slabs were intensively investigated. It was concluded that the punching shear capacity, ductility and energy consumption decreased with the increase of RCA replacement percentage. Research findings indicated that the incorporation of steel fibres could not only improve the energy dissipation capacity and the punching shear capacity of the slab, but also effectively improve the integrity of the slab tension surface and thereby changing the trend from typical punching failure pattern to bending-punching failure pattern. On the basis of the test, the punching shear capacity formula of RAC slabs with and without steel fibres was proposed and discussed.

关键词： recycled aggregate concrete steel fibres slab punching shear recycled coarse aggregates replacement percentage

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hardened properties of high-strength concrete incorporating byproduct fine crushed aggregate as partial replacement

Dammika P. K. WELLALA, Ashish Kumer SAHA, Prabir Kumar SARKER, Vinod RAJAYOGAN

《结构与土木工程前沿（英文）》 2021年第15卷第1期页码 124-135 doi: 10.1007/s11709-020-0673-9

摘要： This paper presents the fresh and hardened properties of high-strength concrete comprising byproduct fine crushed aggregates (FCAs) sourced from the crushing of three different types of rocks, namely granophyre, basalt, and granite. The lowest void contents of the combined fine aggregates were observed when 40% to 60% of natural sand is replaced by the FCAs. By the replacement of 40% FCAs, the slump and bleeding of concrete with a water-to-cement ratio of 0.45 decreased by approximately 15% and 50%, respectively, owing to the relatively high fines content of the FCAs. The 28 d compressive strength of concrete was 50 MPa when 40% FCAs were used. The slight decrease in tensile strength from the FCAs is attributed to the flakiness of the particles. The correlations between the splitting tensile and compressive strengths of normal concrete provided in the AS 3600 and ACI 318 design standards are applicable for concrete using the FCAs as partial replacement of sand. The maximum 56 d drying shrinkage is 520 microstrains, which is significantly less than the recommended limit of 1000 microstrains by AS 3600 for concrete. Therefore, the use of these byproduct FCAs can be considered as a sustainable alternative option for the production of high-strength green concrete.

关键词： fine crushed aggregates quarry dust compressive strength splitting tensile strength drying shrinkage

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Fuel type preference of taxi driver and its implications for air emissions

Feng WANG,Beibei LIU,Bing ZHANG,Jun BI

《环境科学与工程前沿（英文）》 2015年第9卷第4期页码 702-711 doi: 10.1007/s11783-014-0665-x

摘要： Natural gas became an available fuel for taxis in 2005 and had occupied a market share of 43.6% in taxi industry till 2010 in Nanjing, China. To investigate the energy replacement pattern as well as the pollutants reduction potential of the taxi industry, first, the fuel preference determinants of taxi drivers for their next taxis are analyzed. Results show that as an important alternative for the traditional gasoline, natural gas is widely accepted (75%) by taxi drivers. Different from the previous studies which focused on the early stage of cleaner fuel replacement, taxi drivers with various characteristics (such as age, working experience, and education level) are consistent with their fuel preference when they choose their next taxis. Result suggests that policies that concern consumers with specific characteristics may have little effects on the change of the market share, when the alternative fuel market has been developed well. In addition, the increased share of gas in the fuel market achieves a 7.2% reduction of energy consumption. Considering life cycle emissions, the following air pollutants, namely Greenhouse Gases (GHGs), carbonic oxide (CO), nitrogen oxide (NO ), particulate matters (PM) and hydrocarbons (C H ), gain 10.0%, 3.5%, 20.5%, 36.1%, and 26.4% of reduction respectively. Assuming all taxi fleets powered by natural gas with local policy intervention, the energy conservation and the five major air pollutant emissions could achieve the maximum reductions with 12.2%, 16.0%, 8.8%, 22.5%, 44.2%, and 49.4% correspondingly.

关键词： fuel preference energy replacement environmental impacts taxi

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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

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Effects of seeding nucleation agent on geopolymerization process of fly-ash geopolymer

Lapyote PRASITTISOPIN, Issara SEREEWATTHANAWUT

《结构与土木工程前沿（英文）》 2018年第12卷第1期页码 16-25 doi: 10.1007/s11709-016-0373-7

摘要： Geopolymer, an inorganic aluminosilicate material activated by alkaline medium solution, can perform as an inorganic adhesive. The geopolymer technology has a viability to substitute traditional concrete made of portland cement (PC) because replacing PC with fly ash leads to reduced carbon dioxide emissions from cement productions and reduced materials cost. Although fly ash geopolymer stimulates sustainability, it is slow geopolymerization reaction poses a challenge for construction technology in term of practicality. The development of increasing geopolymerization reaction rate of the geopolymer is needed. ?The purpose of this study is to evaluate seeding nucleation agents (NA) of fly ash geopolymer that can accelerate polymerization reactions such that the geopolymer can be widely used in the construction industry. Results from the present study indicate that the use of NA (i.e., Ca(OH) ) can be potentially used to increase geopolymerization reaction rate and improve performance characteristics of the fly ash geopolymer product.

关键词： fly ash geopolymer nucleation agent portland cement replacement

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HEAE气溶胶出口温度控制的实验研究

张永丰,廖光煊,周晓猛,潘仁明,王华

《中国工程科学》 2006年第8卷第3期页码 79-82

摘要：

高效气溶胶灭火剂（HEAE）是由固体推进剂技术发展而成，属于烟火类药剂。当HEAE灭火剂生成气溶胶，出口气溶胶温度很高，会对被保护空间形成二次危害，影响灭火效果，因此灭火装置喷放时需作降温处理。针对灭火装置的特点，采用外冷却方法，利用固化的化学冷却剂，对高温HEAE燃烧产物实施冷却处理。重点考察了冷却块中冷却剂的含量、冷却块的孔径以及冷却块与HEAE灭火剂重量比对冷却降温效果的影响。结果表明，通过合理调节冷却块中冷却剂的含量、冷却块的孔径以及冷却块与HEAE灭火剂质量比，能有效地降低灭火装置喷口处的气溶胶灭火介质的温度。

关键词：气溶胶灭火剂哈龙替代冷却