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Assessing the premature death due to ambient particulate matter in China’s urban areas from 2004 to 2013

Guoxia MA, Jinnan WANG, Fang YU, Xiaomin GUO, Yanshen ZHANG, Chao LI

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0849-7

摘要： The number of annual premature deaths attributable to China’s air pollution ranged from 350000 to 520000 from 2004 to 2013, while the figure in 2013 reached 9.9% of total deaths in China. In 2004, the life expectancy potential years of life lost was 69.6 and 1.85 years respectively in contrast to 74.4 and 0.67 years respectively in 2013. The number of PYLL attributable to air pollution in the northern regions is found to be larger than that of the southern regions. The Environmental Burden of Disease (EBD) approach for outdoor air pollution has been used to calculate premature deaths and average potential years of life lost attributable to air pollution in China over the past 10 years with differences between the North and the South of the country being analyzed. The results indicate that: (1) Between 2004 and 2013, annual premature deaths attributable to outdoor air pollution in China ranged from 350000 to 520000. In 2013, deaths resulting from air pollution in China represented 9.9% of the country’s total deaths. (2) In 2004, the average life expectancy of the Chinese population and the number of potential years of life lost (PYLL) attributable to air pollution was 69.6 and 1.85 years respectively as compared to 74.4 and 0.67 years respectively in 2013. (3) The number of the PYLL attributable to air pollution in the northern regions of China is found to be larger than that of the southern regions. The PYLL figures of the northern and southern regions in 2004 were 2.3 and 1.8 years, respectively, with a difference of 0.5 years, as compared to 1.4 and 0.7 years respectively with a difference of 0.7 years in 2013.

关键词： Air pollution Public health Premature deaths Health assessment

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Premature melt solidification during mold filling and its influence on the as-cast structure

M. WU, M. AHMADEIN, A. LUDWIG

《机械工程前沿（英文）》 2018年第13卷第1期页码 53-65 doi: 10.1007/s11465-017-0437-y

摘要：

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the so-called “big bang” theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

关键词： premature solidification mold filling as-cast structure modeling

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Collaborative control of fine particles and ozone required in China for health benefit

《环境科学与工程前沿（英文）》 2023年第17卷第8期 doi: 10.1007/s11783-023-1692-2

摘要：

● Increased DAAO offsets 3/4 of the decrease of DAAP in 2013–2020.

关键词： Excess deaths Long-term exposure Fine particle Ozone

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Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network optimization

Xuewei QI,Ke LI,Walter D. POTTER

《环境科学与工程前沿（英文）》 2016年第10卷第2期页码 341-351 doi: 10.1007/s11783-015-0776-z

摘要： The optimization of a water distribution network (WDN) is a highly nonlinear, multi-modal, and constrained combinatorial problem. Particle swarm optimization (PSO) has been shown to be a fast converging algorithm for WDN optimization. An improved estimation of distribution algorithm (EDA) using historic best positions to construct a sample space is hybridized with PSO both in sequential and in parallel to improve population diversity control and avoid premature convergence. Two water distribution network benchmark examples from the literature are adopted to evaluate the performance of the proposed hybrid algorithms. The experimental results indicate that the proposed algorithms achieved the literature record minimum (6.081 M$) for the small size Hanoi network. For the large size Balerma network, the parallel hybrid achieved a slightly lower minimum (1.921M?) than the current literature reported best minimum (1.923M?). The average number of evaluations needed to achieve the minimum is one order smaller than most existing algorithms. With a fixed, small number of evaluations, the sequential hybrid outperforms the parallel hybrid showing its capability for fast convergence. The fitness and diversity of the populations were tracked for the proposed algorithms. The track record suggests that constructing an EDA sample space with historic best positions can improve diversity control significantly. Parallel hybridization also helps to improve diversity control yet its effect is relatively less significant.

关键词： particle swarm optimization (PSO) diversity control estimation of distribution algorithm (EDA) water distribution network (WDN) premature convergence hybrid strategy