Chun Ma

Modeling particulate matter emissions during mineral loading process under weak wind simulation

The quantification of particulate matter emissions from mineral handling is an important problem for the quantification of global emissions on industrial sites. Mineral particulate matter emissions could adversely impact environmental quality in mining regions, transport regions, and even on a global scale. Mineral loading is an important process contributing to mineral particulate matter emissions, especially under weak wind conditions. Mathematical models are effective ways to evaluate particulate matter emissions during the mineral loading process. The currently used empirical models based on the form of a power function do not predict particulate matter emissions accurately under weak wind conditions. At low particulate matter emissions, the models overestimated, and at high particulate matter emissions, the models underestimated emission factors. We conducted wind tunnel experiments to evaluate the particulate matter emission factors for the mineral loading process. A new approach based on the mathematical form of a logistical function was developed and tested. It provided a realistic depiction of the particulate matter emissions during the mineral loading process, accounting for fractions of fine mineral particles, dropping height, and wind velocity.

Radiation partitioning and its relation to environmental factors above a meadow ecosystem on the Qinghai‐Tibetan Plateau

Understanding the energy balance on the Qinghai-Tibetan Plateau is essential for better prediction of global climate change. To characterize the energy balance on the plateau, we examined the radiation partitioning over a Kobresia meadow, the most widely distributed vegetation on the plateau, for the period from 2002 to 2005. The incident solar radiation (R(s)) and net radiation (R(n)) averaged 6298 and 2779 MJ m(-2) yr(-1), respectively. The albedo averaged 0.220 annually, with a slightly low value of 0.202 in the growing season from May to September. An increase in soil water or leaf area index was correlated with a decrease of albedo over the meadow. The annual solar radiation lost 34% as longwave radiation, which was higher than values reported for lowland grasslands. The annual radiation efficiency (R(n)/R(s)) over the meadow, at an average of 0.44, was, however, much lower than that for lowland grasslands. The net longwave radiation (L(n)) and the normalized effective radiation (L(n)/R(s)) over the meadow were much higher than that for the global surface or for lowland grasslands, indicating that the longwave exchange between alpine meadow and atmosphere is the most important component of energy losses. A path analysis suggests that the water vapor pressure, air temperature, and cloud cover are the major factors governing the variations of both the net radiation and the net longwave radiation in the alpine meadow ecosystem.

Application of Multiple Indicators in Environment Evaluation of Coastal Restoration Engineering: A Case Study in Bohai Bay in China

Marine environment especially coastal ecosystem has unique hydrological and biological characteristics. However, increased human activities have caused intertidal area destroyed at alarming rates. Environment protection and restoration engineering have become world’s focus. The coastal ecosystems in Bohai Bay have been recognized for providing various ecological functions. The increasing stress caused by human activities induced changes in this area recently. The governors and researchers have conducted restoration engineering. To find out whether the ecosystem health status of marine environment in this area has been changed correspondingly, multiple ecological indicators of different levels including diversity, species biomass and abundance, and thermodynamic indicators were applied. The indicators include Shannon-Wiener index, Margalef index, W-statistic and exergy. The results showed that the marine environment become to moderate disturbed from severely disturbed after coastal restoration engineering according to all the indicators.

Safety Design for Support Structure of Regional Wind System Engineering

The objective of this study is to calculate, design and evaluate support structure safety of regional wind system engineering. First of all, wind loading was calculated based on the building structure norm. Secondly, support structures of regional wind system engineering were designed using CAD. Finally, structure safety of regional wind system engineering was analyzed with finite element ANSYS software. The results showed that the wind system engineering structure is away from harmful fluctuating. Wind load cycle does not match resonance phenomenon. Under fluctuating wind loads, the engineering windbreak structure displacement and stress were dynamic amplification effect. It was concluded that this method can keep safety in support structure design of regional wind system engineering.

Planning and Construction of Eco-City: Theory Application and Case Study

Eco-city is a city designed and built with a well consideration of environmental impact and inhabited. It dedicated to minimization of required inputs in energy, water and food, and minimization of waste output in heat and pollution. This investigation was conducted to see how eco-city theory be applied in urban planning and construction. This study was performed by introducing the conception of eco-city, summarizing theory background and developing index framework, and analyzing a case of eco-city in China. The “case study” method was used to analyze the application of eco-city conception and theories. The results showed that eco-city conception and theories can be present in a well applying, and can be combined with local characteristic. What is more, international cooperation can be accepted by theory application in planning and construction for eco-city. It was concluded that eco-city theory can be applied in urban planning and construction. Local features and international cooperation can be applied in planning and construction of eco-city.

Effect on Marine Ecological Environment of COD Emission of Wastewater

The paper uses the research means of numerical simulation for marine pollution problem of the ocean dumps from offshore industries, which is concerned by the coastal countries; it adopts ECOM Water Quality Model. It has carried out the simulation research on those projects influence on the environment of sea area. By taking COD of wastewater as the research object, the paper confirmed the influence range of COD emission on marine ecological environment.

Effect on Hydrodynamic and Erosion-Deposition Characteristics after Sea Wall Backout

The article analyses and predicts the hydrodynamic feature of Zhifu bay on the basis of Ecomsed model, thus the calculation accuracy is improved. And then it predicts erosion-deposition characteristics of the study sea area. The paper assesses the influence of the sea wall backout in aspects of hydrodynamic and erosion-deposition environment. Simulating results show that the velocity of flow will increase after the sea wall backout and the ability of water exchange will be improved gradually. Research shows that the deposition-dominating areas are located at the north and east of study area, while the southeast side area is dominated by erosion. The accretion tendency will weaken in south of study area together with the accretion thickness 1cm/a annually, while the accretion thickness is 5cm/a in southeast of study area.

Applying Numerical Simulation for Emergency Evacuation in Architectural Engineering

This study applies numerical simulation for emergency evacuation in architectural engineering. The study considered a series of models for simulating emergency evacuation in architectural engineering. The results showed that the time of emergency evacuation relates to maximum velocity and crowd density through horizontal open space, and relates to vertical gradient under vertical evacuation. It was concluded that the risk of emergency response for architectural engineering connected with evacuating capability of builders and circumstance of building site.

Suitability Analysis of Ecological Restoration for Coastal Area under Transportation Construction

Harbors or seaports are major hub of human economic activities, and also centers of environmental issues, which have environmental impacts on the estuary, tidal marshes and coastal wetlands. This paper analyzed the impact of transportation construction on coastal area, reviewed the ecological restoration techniques for habitat under transportation construction, proposed the procedure of suitability analysis of ecological restoration and established an evaluation criteria framework of ecological restoration suitability. The suitability framework which is set up by using Analytic Hierarchy Process (AHP) in this paper could be applied to analyze suitability for ecological restoration of transportation construction projects.