安全状态评价模型构模原理及其状态程度与状态存在程度的表达方法研究

运用系统科学理论对安全状态评价模型构模原理进行阐述;根据评价系统状态的模糊性特征,结合人们对安全状态的认识、理解和接受方式,提出了评价系统状态程度与状态存在的可能性多值表达方法     

“八五”期间辽化地区大气环境质量剖析及防治

根据“八五”期间辽化地区环境监测值,阐述了辽化地区“八五”期间的大气质量状况,变化规律,分析了大气污染原因及防治对策．     

Simulation of aquatic food web and species interactions by adaptive agents embodied with evolutionary computation: a conceptual framework

Individual-based and state variable-based adaptive agents (AA) are discussed regarding their relevance to different types of ecosystems. Individual-based AA proved applicable to a spatially explicit simulation of highly simplified terrestrial food webs. State variable-based AA with evolutionary computation (EC) embodied are suggested for the simulation of aquatic food webs and plankton species interactions. Embodiment of EC in AA can be achieved by evolving predictive rules (ER), differential equations (EDE) or artificial neural networks (ANN) derived from a diverse lake database. In order to provide ecosystem simulation with resilience to environmental change, agent banks can be created containing alternative agents for same species or functional groups from different lakes. State variable-based AA are currently tested for aquatic ecosytem simulation by means of a diverse lake database. It promises to overcome constraints by the rigidity of traditional lake ecosystem models.     

Validation of not-at-fault driver representativeness assumption for quasi-induced exposure using U.S. national traffic databases

Introduction:The quasi-induced exposure (QIE) method has been widely implemented into traffic safety research. One of the key assumptions of QIE method is that not-at-fault drivers represent the driving population at the time of a crash. Recent studies have validated the QIE representative assumption using not-at-fault drivers from three-or-more vehicle crashes (excluding the first not-at-fault drivers; D3_other) as the reference group in single state crash databases. However, it is unclear if the QIE representativeness assumption is valid on a national scale and is a representative sample of driving population in the United States. The aims of this study were to assess the QIE representativeness assumption on a national scale and to evaluate if D3_other could serve as a representative sample of the U.S. driving population. Method: Using the Fatality Analysis Reporting System (FARS) and the National Occupant Protection Use Survey (NOPUS), distributions of driver gender, age, vehicle type, time, and roadway type among the not-at-fault drivers in clean two-vehicle crashes, the first not-at-fault drivers in three-or-more-vehicle crashes, and the remaining not-at-fault drivers in three-or-more vehicle crashes were compared to the driver population observed in NOPUS. Results: The results showed that with respect to driver gender, vehicle type, time, and roadway type, drivers among D3_other did not show statistical significant difference from NOPUS observations. The age distribution of D3_other driver was not practically different to NOPUS observations. Conclusions: Overall, we conclude that D3_other drivers in FARS represents the driving population at the time of the crash. Practical applications: Our study provides a solid foundation for future studies to utilize D3_other as the reference group to validate the QIE representativeness assumption and has potential to increase the generalizability of future FARS studies.     

Using native plants as problem-solvers

The Federal Highway Administration encourages state highway agencies to use native plants in erosion control, revegetation, and landscaping solutions. This paper explains both policy reasons and technical reasons for the use of native plants. How native species can be used is shown through a roadside case study. Other applications of native plant use will be explained through a plant community approach.     

A note on the measurement of agglomeration economies with compensation for urban disamenities

The net agglomeration and disamenities approaches to the measurement of agglomeration economies are merged. The net agglomeration view is represented by a labor demand function derived from Segal (D. Segal, Rev. Econ. Stat. 48, 339–350 (1976)). The disamenities view is represented by an upward-sloping labor supply function derived from Izraeli (O. Izraeli, Urban Stud. 14, 275–290 (1977)). Three cases are simulated. Case I is the benchmark case and assumes a linear homogeneous production function, no agglomeration economies, and no perceived environmental quality differences between cities. Cases II and III combine Segal and Izraeli by introducing agglomeration economies, an upward-sloping labor supply function, and a change in the level of air pollution. The results demonstrate the feasibility of isolating the output of market goods and environmental goods within a common framework.     

Vertical profiles of biogenic volatile organic compounds as observed online at a tower in Beijing

Vertical profiles of isoprene and monoterpenes were measured by a proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) at heights of 3, 15, 32, 64, and 102 m above the ground on the Institute of Atmospheric Physics (IAP) tower in central Beijing during the winter of 2016 and the summer of 2017. Isoprene mixing ratios were larger in summer due to much stronger local emissions whereas monoterpenes were lower in summer due largely to their consumption by much higher levels of ozone. Isoprene mixing ratios were the highest at the 32 m in summer (1.64 ± 0.66 ppbV) and at 15 m in winter (1.41 ± 0.64 ppbV) with decreasing concentrations to the ground and to the 102 m, indicating emission from the tree canopy of the surrounding parks. Monoterpene mixing ratios were the highest at the 3 m height in both the winter (0.71 ± 0.42 ppbV) and summer (0.16 ± 0.10 ppbV) with a gradual decreasing trend to 102 m, indicting an emission from near the ground level. The lowest isoprene and monoterpene mixing ratios all occurred at 102 m, which were 0.71 ± 0.42 ppbV (winter) and 1.35 ± 0.51 ppbV (summer) for isoprene, and 0.42 ± 0.22 ppbV (winter) and 0.07 ± 0.06 ppbV (summer) for monoterpenes. Isoprene in the summer and monoterpenes in the winter, as observed at the five heights, showed significant mutual correlations. In the winter monoterpenes were positively correlated with combustion tracers CO and acetonitrile at 3 m, suggesting possible anthropogenic sources.     

无机盐对城市污泥堆肥处理中重金属Pb和Zn的形态影响研究

以沈北新区虎台镇污水处理厂剩余活性污泥作为研究对象,采用Tessier顺序浸提法浸提污泥中的重金属Pb和Zn,对其在堆肥过程中不同形态的变化规律以及无机盐对重金属稳定态的影响进行研究。结果表明:污泥中重金属Pb和Zn的含量均符合国家相关控制标准(GB 18918-2002和CJ248-2007);堆肥处理明显改变了污泥中重金属的形态分布,Pb与Zn的可交换态分别降低了31.15%和14.14%,残渣态分别增加12.79%和16.35%,显著地降低了重金属的生物有效性;分别向污泥中加入不同无机盐后堆肥,其重金属含量均有向稳定态转变的趋势。其中,加入碳酸铵的样品转变率最高,Pb与Zn的稳定态含量最高可达83.95%与81.13%。     

WATER QUALITY TRENDS IN LAKE TOHOPEKALIGA,FLORIDA, USA: RESPONSES TO WATERSHED MANAGEMENT1

ABSTRACT: Water quality in eutrophic Lake Tohopekaliga, Florida, improved markedly from 1982 to 1992 as a result of reductions in phosphorus and nitrogen loading to the lake. Annual budgets of water, chloride, phosphorus and nitrogen were constructed for the lake, and indicate it is a sink for phosphorus and a source for nitrogen. Water column concentrations of total phosphorus, soluble reactive phosphorus, total nitrogen, dissolved inorganic nitrogen, and chlorophyll a all declined as external inputs of nutrients decreased. Water column nitrogen: phosphorus ratios have increased, suggesting a probable shift from nitrogen- to phosphorus-limitation. This apparent shift in nutrient limitation status also is supported by comparisons of the mean Trophic State Indices for phosphorus, nitrogen, and chlorophyll a. These improvements in water quality are attributed to the diversion of wastewater treatment plant effluent from the lake, and the increased use of wet retention ponds for stormwater runoff.     

Fog simulation using a mesoscale model in and around the Yodo River Basin, Japan

In this study,fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin,Japan.The purpose is to investigate the MM5 performance of fog simulation for long-term periods.The simulations were performed for January,February,March,and July,2005 with a coarse 3-kin and a nested fine 1-km grid domains. Results of the simulations were compared with data from ten meteorological observatories,fog sampling site in Mt.Rokko,and visibility measu...