scholarly journals Supplementary material to "High efficiency of livestock ammonia emission controls on alleviating particulate nitrate during a severe winter haze episode in northern China"

2018 ◽  
Author(s):  
Zhenying Xu ◽  
Mingxu Liu ◽  
Yu Song ◽  
Shuxiao Wang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Northern China ◽  
Ammonia Emission ◽  
Severe Winter ◽  
Emission Controls ◽  
Haze Episode ◽  
Supplementary Material

scholarly journals High efficiency of livestock ammonia emission controls in alleviating particulate nitrate during a severe winter haze episode in northern China

2019 ◽  
Vol 19 (8) ◽  
pp. 5605-5613 ◽  
Author(s):  
Zhenying Xu ◽  
Mingxu Liu ◽  
Minsi Zhang ◽  
Yu Song ◽  
Shuxiao Wang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Northern China ◽  
Forecast Model ◽  
Ammonia Emission ◽  
Severe Winter ◽  
Nh3 Emission ◽  
Emission Controls ◽  
High Pollution ◽  
Haze Episode ◽  
Thermodynamic Equilibrium Model

Abstract. Although nitrogen oxide (NOx) emission controls have been implemented for several years, northern China is still facing high particulate nitrate (NO3-) pollution during severe haze events in winter. In this study, the thermodynamic equilibrium model (ISORROPIA-II) and the Weather Research and Forecast model coupled with chemistry (WRF-Chem) were used to study the efficiency of NH3 emission controls on alleviating particulate NO3- during a severe winter haze episode. We found that particulate-NO3- formation is almost NH3-limited in extremely high pollution but HNO3-limited on the other days. The improvements in manure management of livestock husbandry could reduce 40 % of total NH3 emissions (currently 100 kt month−1) in northern China in winter. Consequently, particulate NO3- was reduced by approximately 40 % (on average from 40.8 to 25.7 µg m−3). Our results indicate that reducing livestock NH3 emissions would be highly effective in reducing particulate NO3- during severe winter haze events.

scholarly journals High efficiency of livestock ammonia emission controls on alleviating particulate nitrate during a severe winter haze episode in northern China

2018 ◽  
Author(s):  
Zhenying Xu ◽  
Mingxu Liu ◽  
Yu Song ◽  
Shuxiao Wang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Northern China ◽  
Forecast Model ◽  
Ammonia Emission ◽  
Manure Management ◽  
Severe Winter ◽  
Nh3 Emission ◽  
Emission Controls ◽  
Haze Episode ◽  
Thermodynamic Equilibrium Model

Abstract. Although nitrogen oxide (NOx) emission controls have been implemented for several years in northern China, recent observations show particulate nitrate (NO3−) is becoming increasingly important during haze episodes. In this study, we find that particulate NO3− formation would easily become NH3-limited under severe haze conditions, enhancing its sensitivity to NH3 emission controls. Furthermore, improved manure management of livestock husbandry could reduce 40 % of NH3 emissions (currently 100 kiloton per a month) in winter of northern China. Under this emission reductions scenario, simulations from the thermodynamic equilibrium model (ISORROPIA-II) and the Weather Research and Forecast model coupled chemistry (WRF-Chem) all show that particulate NO3− could be reduced by approximately 40 % during a typical severe haze episode (averagely from 40.8 to 25.7 μg/m3). Our results indicate that reducing livestock NH3 emissions would be highly effective to reduce particulate NO3− during severe winter haze events.

How grass contributes to controlling hillslope erosion

2020 ◽  
Author(s):  
Chengzhong Pan ◽  
Lan Ma
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
High Efficiency ◽  
Northern China ◽  
Bare Soil ◽  
Soil Characteristics ◽  
Vegetation Coverage ◽  
Grass Cover ◽  
Run Off ◽  
Set Up

<p>The aim of this study was to investigate how the spatial distribution of grass influenced run-off and erosion from a hillslope with loess and cinnamon soils in the rocky area of Northern China. We set up a trial to test the two soils with different treatments, including bare soil (BS), grass strips on the upper (UGS) and lower (DGS) parts of the slope, grass cover over the entire slope (GS), and a grass carpet on the lower part of the slope (GC), under simulated rainfall conditions. The results showed that the run-off coefficients for the loess and cinnamon soils decreased by between 4% and 20% and by between 2% and 37%, respectively, when covered with grass. Grass spatial distribution had little effect on the run-off, but more effect on erosion than vegetation coverage degree. The most effective location of grass cover for decreasing hillslope erosion was at the foot, and the high efficiency was mainly due to controlling of rill formation and sediment deposition. The soil loss from GS, DGS, and GC on the loess and cinnamon soils was between 77% and 93% less and 55% and 80% less, respectively, compared with the loss from BS. However, the soil characteristics had little effect on soil erosion for well-vegetated slopes. The results highlight the importance of vegetation re-establishment at the foot of hillslope in controlling soil erosion.</p>

scholarly journals Thallus sectioning as an efficient monospore release method in Pyropia yezoensis (Bangiales, Rhodophyta)

2019 ◽  
Vol 32 (4) ◽  
pp. 2195-2200 ◽  
Author(s):  
Nianci Chen ◽  
Lei Tang ◽  
Xiaowei Guan ◽  
Rui Chen ◽  
Min Cao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Economic Value ◽  
Northern China ◽  
Pyropia Yezoensis ◽  
Effect Of Temperature ◽  
Seeding Strategy ◽  
Increasing Demand ◽  
Short Time ◽  
Release Method

AbstractThe red seaweed Pyropia yezoensis is a marine crop of important economic value and is widely cultivated in the coastal areas of northern China. The current seedling-raising system relies on the germination of conchospores, a process not fast enough to meet the increasing demand from farmers. In this study, we developed a monospore-dependent seedling method based on the asexual reproduction of the Pyropia thallus. The Pyropia thallus was physically sectioned into small pieces (microthalli) that were cultivated at 15 °C. The algal cells in the microthalli became morphologically condensed, underwent cell division, and then developed into monospores on the 5th day. The monospores were able to attach to the seeding rope in 24 h and germinated into healthy thalli. To optimize the efficiency of monospore release, we tested the effect of temperature and the size and original positions of the microthalli as well as the age of the mother thallus. Microthalli with a size of 30–50 cells from the middle and apex of 21-day-old thalli cultivated at 15 °C yielded the optimum production of monospores. Theoretically, in this thallus-to-thallus seeding strategy, 0.1 g of thallus could produce at least 107 monospores, with the same number of offspring thallus seedlings. Taking all of these advantages together, including the high efficiency, short time, low cost and easy operation, this physical sectioning method could serve as a promising seed source especially for new cultivars with superior traits in Pyropia farming and rapid replenishment of seedlings when thalli undergo disastrous diseases.

The emergence of China as an LNG super user

2019 ◽  
Vol 59 (2) ◽  
pp. 667
Author(s):  
Jane Norman
Keyword(s):  
Public Health ◽  
Air Quality ◽  
Natural Gas ◽  
Northern China ◽  
Gas Production ◽  
Liquefied Natural Gas ◽  
Chinese Government ◽  
Severe Winter ◽  
Health Concerns ◽  
The Government

China has recently undergone a period of rapid industrialisation and growth. In 2009 the country became the world’s largest energy consumer, with much of this demand being historically met by coal. This heavy reliance on coal, coupled with rapid urbanisation, resulted rising smog levels and deteriorating air quality. In response to public health concerns, the Chinese government introduced several policies to transition to lower polluting fuels, with natural gas being the main beneficiary. In 2017 China’s liquefied natural gas (LNG) imports grew by an enormous 46%, to 38 Mt, as the government ordered heavy manufacturers in two provinces and 26 cities to switch from coal to gas and households to cut coal use for winter heating. Although government air quality targets were met, it resulted in severe winter gas shortages particularly in northern China. A more measured coal-to-gas switching program was undertaken in 2018 and LNG imports continued to surge reaching 54 Mt, another 41% year-on-year increase. Going forward Chinese LNG growth is expected to face competition from increased pipeline gas imports and indigenous gas production. However, there are still many risks to these forecasts, and much to play out as the market continues to be liberalised. As such, Chinese LNG demand presents an enormous opportunity for LNG suppliers both now, and well into the future.

Sign in / Sign up

Export Citation Format

Share Document