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基于分区气化模型的MSW燃烧过程模拟研究
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作者 王汝佩 黄群星 +2 位作者 李文娟 池涌 严建华 《环境工程学报》 CAS CSCD 北大核心 2016年第6期3185-3192,共8页
针对一种新型两段式生活垃圾分区气化燃烧装置,提出了基于分区气化模型的垃圾热转化过程数值模拟方法。该方法耦合化学反应动力学和流体动力学软件预测移动床层垃圾的气化以及炉内气相空间的燃烧过程。通过对组分及热值差异较大的2种生... 针对一种新型两段式生活垃圾分区气化燃烧装置,提出了基于分区气化模型的垃圾热转化过程数值模拟方法。该方法耦合化学反应动力学和流体动力学软件预测移动床层垃圾的气化以及炉内气相空间的燃烧过程。通过对组分及热值差异较大的2种生活垃圾在炉内的反应过程进行模拟,得到了炉内的气相组分、温度及流场的分布。结果表明,该方法能够很好地适用于复杂组分的垃圾热转化过程模拟研究。高水分、低热值的生活垃圾气化后再燃炉膛出口温度处于973~1 073 K,不利于二恶英的生成控制。前拱二次风的增加不仅加强了炉内的湍流扰动,而且加强了炉内主反应区的温度。经过对流场和温度场进行优化,烟气的停留时间延长,炉膛出口烟气中的可燃气体组分大大降低,而且NO的浓度降低了近一个数量级。 展开更多
关键词 分区气化 控氧热转化 反应动力学 自由焓最小化
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Partition airflow varying features of chaos-theory-based coalmine ventilation system and related safety forecasting and forewarning system 被引量:1
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作者 Zhang Xiaoqiang Cheng Weimin +2 位作者 Zhang Qin Yang Xinxiang Du Wenzhou 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第2期269-275,共7页
To realize real-time monitoring and short-term forecasting and forewarning of coalmine ventilation systems(CVS), in this paper, we first established a joint surface and underground CVS safety management system consist... To realize real-time monitoring and short-term forecasting and forewarning of coalmine ventilation systems(CVS), in this paper, we first established a joint surface and underground CVS safety management system consisting of main ventilation fan, safety-partition linked passageways, and air-required locations. We then applied chaos theory to identify the air quantity and gas concentration of underground partition boundaries, and adopted a fixed data quantity, multi-step progressive, weighted first-order local-domain method to setup a chaos prediction model and a CVS safety forecasting and forewarning system formed by the normal change level, orange forewarning level, and red alarm level. We next conduct the on-field application of the system in a coalmine in Jining, Shandong, China. The results showed that (1) in the statistical scale of 5 min, the changes in both air quantity and gas concentration along CVS partition airflow boundaries were characteristic of chaos and could be used for short-term chaos prediction, and the latter was more chaotic than the former;(2) the setup chaos prediction model had a higher prediction precision and the established safety prediction system could not only predict the variation in CVS stability but also reflect the rationality of underground mining intensity. Thus, this CVS safety forecasting and forewarning system is of better application value. 展开更多
关键词 Mine ventilation system Safety partition Reconstructed phase space Maximum Lyapunov exponent Chaos forecasting and forewarning
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Automatic detection of oceanic mesoscale eddies in the South China Sea 被引量:1
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作者 夏琼 申辉 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1334-1348,共15页
This study focuses on the spatial and temporal distribution characteristics of mesoscale eddies in the South China Sea(SCS). An automatic eddy detection method,based on the geometry of velocity vectors,was adopted to ... This study focuses on the spatial and temporal distribution characteristics of mesoscale eddies in the South China Sea(SCS). An automatic eddy detection method,based on the geometry of velocity vectors,was adopted to obtain an eddy dataset from 21 years of satellite altimeter data. Analysis revealed that the number of anticyclonic eddies was nearly equal to cyclonic eddies; in the SCS,cyclonic eddies are generally stronger than anticyclonic eddies and anticyclonic eddies are larger and longer-lived than cyclonic eddies. Anticyclonic eddies tend to survive longer in the spring and summer,while cyclonic eddies have longer lifetimes in the autumn and winter. The characteristics and seasonal variations of eddies in the SCS are strongly related to variations in general ocean circulation,in the homogeneity of surface wind stress,and in the unevenness of bottom topography in the SCS. The spatial and temporal variation of mesoscale eddies in the SCS could,therefore,be an important index for understanding local hydrodynamics and regional climate change. 展开更多
关键词 South China Sea mesoscale eddies eddy detection ALTIMETER STATISTICS
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Uncertainty in crossing time of 2 °C warming threshold over China 被引量:16
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作者 Xiaolong Chen Tianjun Zhou 《Science Bulletin》 SCIE EI CAS CSCD 2016年第18期1451-1459,共9页
The 2 ℃ warming target has been used widely in global and regional climate change research. Previous studies have shown large uncertainties in the time when surface air temperature (SAT) change over China will reac... The 2 ℃ warming target has been used widely in global and regional climate change research. Previous studies have shown large uncertainties in the time when surface air temperature (SAT) change over China will reach 2℃ rela- tive to the pre-industrial era. To understand the uncertainties, we analyzed the projected SAT in the twenty-first century using 40 state-of-the-art climate models under two Repre- sentative Concentration Pathways (RCP4.5 and RCPS.5) from the Coupled Model Intercomparison Project Phase 5. The 2℃ threshold-crossing time (TCT) of SAT averaged across China was around 2033 and 2029 for RCP4.5 and RCP8.5, respectively. Considering a 4-1o- range of inter- model SAT change, the upper and lower bounds of the 2 ℃ TCT could differ by about 25 years or even more. Uncer- tainty in the projected SAT and the warming rate around the TCT are the two main factors responsible for the TCT uncertainty. The former is determined by the climate sensi- tivity represented by the global mean surface temperature response. About 45 % of the intermodel variance of the projected 2 ~C TCT for averaged SAT over China can be explained by climate sensitivity across the models, which is contributed mainly by central and southern China. In a cli- mate more sensitive to CO2 forcing, stronger greenhouse effect, less stratus cloud over the East Asian monsoon region, and less snow cover on the Tibetan Plateau result in increased downward longwave radiation, increased shortwave radia- tion, and decreased shortwave radiation reflected by the surface, respectively, all of which may advance the TCT. 展开更多
关键词 2 °C threshold Projection uncertainty China region CMIP5 Climate sensitivity
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Chronological constraints on multi-staged rapid cooling of the Tianshan Mountains inferred from apatite fission track analysis of modern river sands 被引量:2
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作者 WANG LiNing JI JianQing +2 位作者 SUN DongXia XU QinQin HAN BaoFu 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第8期1305-1319,1-5,共15页
The extreme modern elevation of the Tianshan Mountains reflects the Cenozoic deformation. Apatite Fission Track (AFI) chronometry is widely used to study the latest cooling stages caused by tectonic process or by ex... The extreme modern elevation of the Tianshan Mountains reflects the Cenozoic deformation. Apatite Fission Track (AFI) chronometry is widely used to study the latest cooling stages caused by tectonic process or by exhumation in the uppermost crust. However, uncertainties remain over timing constraints on thermal history of the Tianshan Mountains since the Cenozoic though a great mount of dating work had been done in this area. To address this issue, modern river sands from the drainage basin on the piedmont of the Tianshan Mountains were sampled to integrate regional information. Single grains were dated with the AFT method, and then different grain-age components were identified to provide thermochronological constraints of their sources. Combined with discussion of previous dataset, our results show the multi-staged rapid cooling cluster at 46-32, 25-24, 19-13, 8-6, and -3 Ma, respectively. We interpreted these cooling events as a result of interplays between the Cenozo- ic tectonic uplift of the mountains and regional climate change. 展开更多
关键词 Tianshan Mountains detrital apatite fission track cooling stages EXHUMATION thermal history
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Variations in soil moisture over the ‘Huang-Huai-Hai Plain' in China due to temperature change using the CNOP-P method and outputs from CMIP5 被引量:1
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作者 SUN GuoDong PENG Fei MU Mu 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第10期1838-1853,共16页
In this study, the variations in surface soil liquid water(SSLW) due to future climate change are explored in the‘Huang-Huai-Hai Plain'(‘3H') region in China with the Common Land Model(CoLM). To evaluate the... In this study, the variations in surface soil liquid water(SSLW) due to future climate change are explored in the‘Huang-Huai-Hai Plain'(‘3H') region in China with the Common Land Model(CoLM). To evaluate the possible maximum response of SSLW to climate change, the combination of the conditional nonlinear optimal perturbation related to the parameter(CNOP-P) approach and projections from 10 general circulation models(GCMs) of the Coupled Model Intercomparison Project5(CMIP5) are used. The CNOP-P-type temperature change scenario, a new type of temperature change scenario, is determined by using the CNOP-P method and constrained by the temperature change projections from the 10 GCMs under a high-emission scenario(the Representative Concentration Pathway 8.5 scenario). Numerical results have shown that the response of SSLW to the CNOP-P-type temperature scenario is stronger than those to the 11 temperature scenarios derived from the 10 GCMs and from their ensemble average in the entire ‘3H' region. In the northern region, SSLW under the CNOP-P-type scenario increases to0.1773 m^3 m^(-3); however, SSLW in the scenarios from the GCMs fluctuates from 0.1671 to 0.1748 m^3 m^(-3). In the southern region,SSLW decreases, and its variation(–0.0070 m^3 m^(-3)) due to the CNOP-P-type scenario is higher than each of the variations(–0.0051 to –0.0026 m^3 m^(-3)) due to the scenarios from the GCMs. 展开更多
关键词 CNOP-P Surface soil liquid water CMIP5 Climate change Seasonal and regional heterogeneity
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