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Dynamic response of precast segmental bridge columns under heavy truck impact

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 327-349 doi: 10.1007/s11709-023-0911-z

摘要： Considering the wide application of precast segmental bridge columns (PSBCs) in engineering practice, impact-resistant performance has gained significant attention. However, few studies have focused on PSBCs subjected to high-energy impacts caused by heavy truck collisions. Therefore, the behavior of PSBCs under a heavy truck impact was investigated in this study using high-fidelity finite element (FE) models. The detailed FE modeling methods of the PSBCs and heavy trucks were validated against experimental tests. The validated modeling methods were employed to simulate collisions between PSBCs and heavy trucks. The simulation results demonstrated that the engine and cargo caused two major peak impact forces during collision. Subsequently, the impact force, failure mode, displacement, and internal force of the PSBCs under heavy truck impacts were scrutinized. An extensive study was performed to assess the influence of the section size, truck weight, impact velocity, and number of precast segments on the impact responses. The truck weight was found to have a minor effect on the engine impact force. Damage was found to be localized at the bottom of the three segments, with the top remaining primarily undamaged. This parametric study demonstrated that larger cross-sections may be a preferred option to protect PSBCs against the impact of heavy trucks.

关键词： precast segmental bridge columns     heavy truck     collision     dynamic response    

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A practical multi-lane factor model of bridges based on multi-truck presence considering lane load disparities

《结构与土木工程前沿（英文）》 2021年 第15卷 第4期   页码 877-894 doi: 10.1007/s11709-021-0756-2

摘要： Many bridge design specifications consider multi-lane factors (MLFs) a critical component of the traffic load model. Measured multi-lane traffic data generally exhibit significant lane disparities in traffic loads over multiple lanes. However, these disparities are not considered in current specifications. To address this drawback, a multi-coefficient MLF model was developed based on an improved probabilistic statistical approach that considers the presence of multiple trucks. The proposed MLF model and approach were calibrated and demonstrated through an example site. The model sensitivity analysis demonstrated the significant influence of lane disparity of truck traffic volume and truck weight distribution on the MLF. Using the proposed approach, the experimental site study yielded MLFs comparable with those directly calculated using traffic load effects. The exclusion of overloaded trucks caused the proposed approach, existing design specifications, and conventional approach of ignoring lane load disparity to generate comparable MLFs, while the MLFs based on the proposed approach were the most comprehensive. The inclusion of overloaded trucks caused the conventional approach and design specifications to overestimate the MLFs significantly. Finally, the benefits of the research results to bridge practitioners were discussed.

关键词： bridges     multi-lane factor     traffic load     lane load disparity     multi-truck presence     weigh-in-motion data    

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Multi-axle dynamic steering system of truck-howitzer

LI Yanliang, GAO Xiuhua, ZHANG Chunqiu, SUN Yubo

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 44-49 doi: 10.1007/s11465-008-0002-9

摘要： A two-degree-of-freedom (2-DOF) steering model of multi-axle vehicle was established. The steering center position, the relationship between the steering angle and the vehicle velocity, and the minimum turn radius were deduced on the basis of the proportional control with a zero sideslip angle. Results indicate that the system stability is decided by the vehicle barycenter position and the lateral stiffness of a tire. Under this control, the steady value of the lateral acceleration is obviously diminished and the yaw angular velocity changes little under any vehicle velocity. The system rapidly responds, the vehicle smoothly steers, and its handling stability is prominently improved.

关键词： multi-axle     acceleration     relationship     smoothly     handling stability    

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Co-pyrolysis of sludge and kaolin/zeolite in a rotary kiln: Analysis of stabilizing heavy metals

《环境科学与工程前沿（英文）》 2022年 第16卷 第7期 doi: 10.1007/s11783-021-1488-1

摘要：

• Adding kaolin/zeolite promotes the formation of stable heavy metals.

关键词： Co-pyrolysis     Sewage sludge     Heavy metals     Rotary kiln     Immobilization mechanism    

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Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

《环境科学与工程前沿（英文）》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1728-7

摘要：

● A higher sulfur content reduced the curing rate of Cr in glass.

关键词： Dechlorinated fly ash     SO3     Heavy metal     Chemical speciation     Glass solidification    

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ASSESSMENT OF HEAVY METALS IN HYDROCHAR PRODUCED BY HYDROTHERMAL CARBONIZATION OF DAIRY MANURE

《农业科学与工程前沿（英文）》 2023年 第10卷 第3期   页码 437-447 doi: 10.15302/J-FASE-2023507

摘要：

● Content of heavy metals in hydrochar varies considerably, from 50% to 100%.

关键词： heavy metals     dairy manure     hydrochar     hydrothermal carbonization     waste management    

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Strategies to manage the risk of heavy metal(loid) contamination in agricultural soils

Fang-Jie ZHAO

《农业科学与工程前沿（英文）》 2020年 第7卷 第3期   页码 333-338 doi: 10.15302/J-FASE-2020335

摘要：

Soil contamination with heavy metal(loid)s threatens soil ecological functions, water quality and food safety; the latter is the focus of this review. Cadmium (Cd) and arsenic (As) are the toxic elements of most concern for food safety because they are relatively easily taken up by food crops. Rice is a major contributor of both Cd and As intakes to the Chinese population. Contamination and soil acidification are the main causes of high Cd levels in rice grains produced in some areas of southern China. The risk of Cd and As accumulation in food crops can be mitigated through agronomic practices and crop breeding. Liming is effective and economical at reducing Cd uptake by rice in acid soils. Paddy water management can produce opposite effects on Cd and As accumulation. Many genes controlling Cd and As uptake and translocation have been characterized, paving the way to breeding low accumulating crop cultivars through marker-assisted molecular breeding or genetic engineering. It is important to protect agricultural soils from future contamination. Long-term monitoring of anthropogenic additions and accumulation of heavy metal(loid)s in agricultural soils should be undertaken. Mass-balance models should be constructed to evaluate future trends of metal(loid)s in agricultural soils at a regional scale.

关键词： arsenic     cadmium     food safety     heavy metals     soil contamination    

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Predicting non-carcinogenic hazard quotients of heavy metals in pepper (

Marzieh Mokarram, Hamid Reza Pourghasemi, Huichun Zhang

《环境科学与工程前沿（英文）》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1331-0

摘要： Abstract • There was significant absorption of heavy metals by the pepper in contaminated soils. • The target hazard quotient (THQ) indices followed the order of Pb>Zn>>Cd » Ni. • Relationships exist between contaminated plants and electromagnetic wave. • PCA and random search can select the main spectra and predict THQ for each element. Given the tendency of heavy metals to accumulate in soil and plants, the purpose of this study was to determine the contamination levels of Cd, Ni, Pb, and Zn on peppers (leaves and fruit) grown in contaminated soils in industrial centers. For this purpose, we measured the uptake of the four heavy metals by peppers grown in the heavy metal contaminated soils throughout the four growth stages: two-leaf, growth, flowering, and fruiting, and calculated various vegetation indices to evaluate the heavy metal contamination potentials. Electromagnetic waves were also applied for analyzing the responses of the target plants to various heavy metals. Based on the relevant spectral bands identified by principal component analysis (PCA) and random search methods, a regression method was then employed to determine the most optimal spectral bands for estimating the target hazard quotient (THQ). The THQ was found to be the highest in the plants contaminated by Pb (THQ= 62) and Zn (THQ= 5.07). The results of PCA and random search indicated that the spectra at the bands of b570, b650, and b760 for Pb, b400 and b1030 for Ni, b400 and b880 for Cd, and b560, b910, and b1050 for Zn were the most optimal spectra for assessing THQ. Therefore, in future studies, instead of examining the amount of heavy metals in plants by chemical analysis in the laboratory, the responses of the plants to the electromagnetic waves in the identified bands can be readily investigated in the field based on the established correlations.

关键词： Heavy metals     Plants     Target Hazard Quotient (THQ)     Principal Component Analysis (PCA)     Random search     Electromagnetic wave    

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Recent progress in electrospun nanofibers and their applications in heavy metal wastewater treatment

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 249-275 doi: 10.1007/s11705-022-2245-0

摘要： Novel adsorbents with a simple preparation process and large capacity for removing highly toxic and nondegradable heavy metals from water have drawn the attention of researchers. Electrospun nanofiber membranes usually have the advantages of large specific surface areas and high porosity and allowing flexible control and easy functionalization. These membranes show remarkable application potential in the field of heavy metal wastewater treatment. In this paper, the electrospinning technologies, process types, and the structures and types of nanofibers that can be prepared are reviewed, and the relationships among process, structure and properties are discussed. On one hand, based on the different components of electrospun nanofibers, the use of organic, inorganic and organic−inorganic nanofiber membrane adsorbents in heavy metal wastewater treatment are introduced, and their advantages and future development are summarized and prospected. On the other hand, based on the microstructure and overall structure of the nanofiber membrane, the recent progresses of electrospun functional membranes for heavy metal removal are reviewed, and the advantages of different structures for applications are concluded. Overall, this study lays the foundation for future research aiming to provide more novel structured adsorbents.

关键词： electrospinning     heavy metal     adsorption     nanostructure     wastewater    

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Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients and heavy

Xunan YANG, Shan HUANG, Qunhe WU, Renduo ZHANG, Guangli LIU

《环境科学与工程前沿（英文）》 2013年 第7卷 第6期   页码 851-859 doi: 10.1007/s11783-013-0569-1

摘要： The aim of this study was to investigate the benthic bacterial communities in different depths of an urban river sediment accumulated with high concentrations of nutrients and metals. Vertical distributions of bacterial operational taxonomic units (OTUs) and chemical parameters (nutrients: , , dissolved organic carbon, and acid volatile sulfur; metals: Fe, Zn, and Cu) were characterized in 30 cm sediment cores. The bacterial OTUs were measured using the terminal restriction fragment length polymorphism analysis. Biodiversity indexes and multivariate statistical analyses were used to characterize the spatial distributions of microbial diversity in response to the environmental parameters. Results showed that concentrations of the nutrients and metals in this river sediment were higher than those in similar studies. Furthermore, high microbial richness and diversity appeared in the sediment. The diversity did not vary obviously in the whole sediment profile. The change of the diversity indexes and the affiliations of the OTUs showed that the top layer had different bacterial community structure from deeper layers due to the hydrological disturbance and redox change in the surface sediment. The dominant bacterial OTUs ubiquitously existed in the deeper sediment layers (5–27 cm) corresponding to the distributions of the nutrients and metals. With much higher diversity than the dominant OTUs, the minor bacterial assemblages varied with depths, which might be affected by the sedimentation process and the environmental competition pressure.

关键词： heavy metals     nutrients     sediment profile     terminal restriction fragment length polymorphism    

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Joint effects of Penta-BDE and heavy metals on

Baohua TANG, Lingyan ZHU, Qixing ZHOU

《环境科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 99-110 doi: 10.1007/s11783-010-0260-8

摘要： The joint toxicity of Penta-BDE (Pe-BDE) and heavy metals including cadmium and copper on ( ) was evaluated on the basis of determining the 48 h survival, antioxidative enzyme responses, and lipid peroxidation. The response was classified as additive, greater than additive, or less than additive by comparing the measured “toxic units, TU” with one. Based on the survival of , less-than-additive interactions were found in most of mixtures treatments. This may be attributed to the different toxicity mechanism between Pe-BDE and metals. Cu and Cd played a greater role in toxicity than what Pe-BDE did. As for the superoxide dismutase (SOD) and catalase (CAT) activity, most response was less than additive. For the glutathione -transferases (GST) activity, most of the greater-than-additive responses were found in the Cu plus Pe-BDE treatments, but the additive responses occurred in Cd plus Pe-BDE treatments and binary metal treatments. For lipid peroxide levels, which were measured as malondialdehyde (MDA) levels, less-than-additive response occurred in the 50% Cd plus 50% Cu and ternary mixture treatments. Results suggested that Pe-BDE, Cd, and Cu could induce different patterns of antioxidant enzyme responses, such as antioxidant/prooxidant responses, depending on their capability to produce reactive oxygen species and antioxidant enzymes to detoxify them.

关键词： polybrominated diphenyl ethers (PBDEs)     heavy metal     mixture toxicity     toxic units (TUs)     antioxidant enzyme     lipid peroxidation    

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Human health ambient water quality criteria for 13 heavy metals and health risk assessment in Taihu Lake

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1475-6

摘要：

• The concentrations of 13 heavy metals in Taihu Lake were analyzed.

关键词： Heavy metals     Human health ambient water quality criteria     Taihu Lake     Health risk assessment     Contribution rate    

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EFFECT OF EXOGENOUS ADDITIVES ON HEAVY METAL PASSIVATION AND NITROGEN RETENTION IN PIG MANURE COMPOSTING

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023487

摘要：

● Research on heavy metal passivation and nitrogen emissions is necessary for the pig industry.

关键词： additives     composting     heavy metals passivation     nitrogen retention     pig manure    

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Sulfur mediated heavy metal biogeochemical cycles in coastal wetlands: From sediments, rhizosphere to

《环境科学与工程前沿（英文）》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1523-x

摘要：

• In sediments, the transformation of sulfides may lead to the release of heavy metals.

关键词： Coastal wetland     Heavy metal     Sulfur     Biogeochemical cycle    

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Re-evaluation of several heavy metals removal by natural limestones

Ali SDIRI,Samir BOUAZIZ

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 418-432 doi: 10.1007/s11705-014-1455-5

摘要： Different treatment technologies have been efficiently applied to remove heavy metals from wastewater. Efforts have been made to find out the most economic water treatment technology by using low cost and easily accessible natural materials. On the other hand, heavy metals are the most threatening groundwater contaminants because of their toxicity and harmful effects on human and biota. This review discusses the use of natural geological materials for heavy metal removal in aqueous systems. Special attention has been devoted to natural limestone through a systematic inventory of relevant published reports. The removal of toxic metals may include different mechanisms (e.g., physisorption, chemisorptions, precipitation, etc.), depending on the physico-chemical properties of the material and the removed metal. Sorption of toxic metals (e.g., Pb, Cu, Cd, Zn, Cr, Hg, etc.) onto natural limestone involved precipitation of metal carbonate as a predominant removal process, but often subordinated by adsorption and ion exchange, depending on the physico-chemical properties of the studied limestone.

关键词： limestone     heavy metals     sorption     wastewater     passive treatment technology    

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标题 作者 时间 类型 操作

Dynamic response of precast segmental bridge columns under heavy truck impact

期刊论文

A practical multi-lane factor model of bridges based on multi-truck presence considering lane load disparities

期刊论文

Multi-axle dynamic steering system of truck-howitzer

LI Yanliang, GAO Xiuhua, ZHANG Chunqiu, SUN Yubo

期刊论文

Co-pyrolysis of sludge and kaolin/zeolite in a rotary kiln: Analysis of stabilizing heavy metals

期刊论文

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

期刊论文

ASSESSMENT OF HEAVY METALS IN HYDROCHAR PRODUCED BY HYDROTHERMAL CARBONIZATION OF DAIRY MANURE

期刊论文

Strategies to manage the risk of heavy metal(loid) contamination in agricultural soils

Fang-Jie ZHAO

期刊论文

Predicting non-carcinogenic hazard quotients of heavy metals in pepper (

Marzieh Mokarram, Hamid Reza Pourghasemi, Huichun Zhang

期刊论文

Recent progress in electrospun nanofibers and their applications in heavy metal wastewater treatment

期刊论文

Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients and heavy

Xunan YANG, Shan HUANG, Qunhe WU, Renduo ZHANG, Guangli LIU

期刊论文

Joint effects of Penta-BDE and heavy metals on

Baohua TANG, Lingyan ZHU, Qixing ZHOU

期刊论文

Human health ambient water quality criteria for 13 heavy metals and health risk assessment in Taihu Lake

期刊论文

EFFECT OF EXOGENOUS ADDITIVES ON HEAVY METAL PASSIVATION AND NITROGEN RETENTION IN PIG MANURE COMPOSTING

期刊论文

Sulfur mediated heavy metal biogeochemical cycles in coastal wetlands: From sediments, rhizosphere to

期刊论文

Re-evaluation of several heavy metals removal by natural limestones

Ali SDIRI,Samir BOUAZIZ

期刊论文