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Co-incorporating green manure and crop straw increases crop productivity and improves soil quality with low greenhouse-gas emissions in a crop rotation
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作者 Na Zhao xiquan wang +6 位作者 Jun Ma Xiaohong Li Jufeng Cao Jie Zhou Linmei Wu Peiyi Zhao Weidong Cao 《The Crop Journal》 SCIE CSCD 2024年第4期1233-1241,共9页
In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area,Inner Mongolia,China,organic amendments applied as straw,manure,green manure,and the combination of green manure and ... In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area,Inner Mongolia,China,organic amendments applied as straw,manure,green manure,and the combination of green manure and straw increased wheat and maize yield,soil aggregate stability,and soil microbial activity in comparison with chemical fertilizer,without changing greenhouse gas emission intensity. 展开更多
关键词 Green manure STRAW MANURE Soil organic carbon Soil quality Crop production Diversified cropping
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Nocturnal Low-levelWinds and Their Impacts on Particulate Matter over the Beijing Area 被引量:2
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作者 Yong CHEN Junling AN +5 位作者 Yele SUN xiquan wang Yu QU Jingwei ZHANG Zifa wang Jing DUAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第12期1455-1468,共14页
Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collec... Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collected to analyze the characteristics of low-level nocturnal wind and PM in autumn and winter. Three mountain-plain wind events with wind shear were selected for analysis. The measurements indicated that the maximum wind speeds of the northerly weak low-level jet(LLJ) below 320 m at the suburban site were weaker than those at the urban site, and the LLJ heights and depths at the suburban site were lower than those at the urban site. The nocturnal 140 m mean vertical velocities and the variations in vertical velocity at the urban site were larger than those at the suburban site. A nocturnal breeze with a weak LLJ of ~3 m s^(-1) noticeably offset nocturnal PM transport due to southerly flow and convergence within the northern urban area of Beijing. Characteristics of the nocturnal LLJ, such as start-up time, structure, intensity, and duration, were important factors in determining the decrease in the nocturnal horizontal range and site-based low-level variations in PM. 展开更多
关键词 WEAK low-level jet WIND direction SHEAR WIND lidar low-level PM1
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Effects of red and blue LEDs on in vitro growth and microtuberization of potato single-node cuttings 被引量:5
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作者 Lili CHEN Xuzhang XUE +5 位作者 Yadong YANG Fei CHEN Jie ZHAO xiquan wang Alam Tariful KHAN Yuegao HU 《Frontiers of Agricultural Science and Engineering》 2018年第2期197-205,共9页
The objectives of this study were to investigate the effects of red and blue LEDs on in vitro growth and microtuberization of potato(Solanum tuberosum) singlenode cuttings. Explants were incubated under 6 light treatm... The objectives of this study were to investigate the effects of red and blue LEDs on in vitro growth and microtuberization of potato(Solanum tuberosum) singlenode cuttings. Explants were incubated under 6 light treatments: 100% red LEDs(R), 75% red LEDs + 25%blue LEDs(3 RB), 50% red LEDs + 50% blue LEDs(RB),25% red LEDs + 75% blue LEDs(R3 B), 100% blue LEDs(B) and white LEDs(W). Most of the growth and physiological parameters were significantly higher in3 RB than W. Enhancement of leaf area and chlorophyll concentrations were obtained in B. Leaf stomata were elliptical with the lowest density in 3 RB. However, those in W were round in shape, and those with the smallest size and the highest density were observed in R. Most of the characteristics of microtuberization were also improved in3 RB. The combined spectra of red and blue LEDs increased the number of large microtubers. The fresh weight of individual microtubers in R and W were increased, but not their number. These results suggest that, of the treatments assessed, 3 RB is optimal for the in vitro growth of potato plantlets and the combination of red and blue LEDs is beneficial for microtuberization. 展开更多
关键词 blue LED MICROTUBER plant tissue culture potato plantlets in vitro red LED
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Observation of Wind Shear during Evening Transition and an Estimation of Submicron Aerosol Concentrations in Beijing Using a Doppler Wind Lidar 被引量:5
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作者 Yong CHEN Junling AN +3 位作者 xiquan wang Yele SUN Zifa wang Jing DUAN 《Journal of Meteorological Research》 SCIE CSCD 2017年第2期350-362,共13页
The wind speed and direction measured over six months by a Doppler wind lidar(Windcube-8)were compared with wind cup anemometers mounted on the 325-m Beijing meteorological tower(BMT).Five mountain–plain wind cas... The wind speed and direction measured over six months by a Doppler wind lidar(Windcube-8)were compared with wind cup anemometers mounted on the 325-m Beijing meteorological tower(BMT).Five mountain–plain wind cases characterized by wind direction shear were selected based on the high-frequency(1.1 s)wind profile of the Windcube-8 and analyzed with 1-h mesoscale surface weather charts.Also analyzed was the relationship between insitu PM_1(aerodynamic diameter≤1μm)concentrations measured at 260 m on BMT and the carrier-to-noise ratio(CNR)of the co-located Windcube-8.The results showed that the 10-min averaged wind speed and direction were highly correlated(R=0.96–0.99)at three matched levels(80,140,and 200 m).The evening transition duration was1–3 h,with an average wind speed of 1 m s^(–1) at 80 m above the ground.In addition,there was a zero horizontalwind-speed zone along the wind direction shear line,and in one case,the wind speed was characterized by a Kelvin–Helmholtz gravity wave.The variability of the PM_1 concentrations was captured by the CNR of the Windcube-8 in a fair weather period without the long-range transport of dust. 展开更多
关键词 mountain–plain wind wind shear wind lidar PM_1
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Evolutionary processes and sources of high-nitrate haze episodes over Beijing,Spring 被引量:2
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作者 Ting Yang Yele Sun +4 位作者 Wei Zhang Zifa wang Xingang Liu Pingqing Fu xiquan wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第4期142-151,共10页
Rare and consecutive high-nitrate haze pollution episodes were observed in Beijing in spring2012. We present detailed characterization of the sources and evolutionary mechanisms of this haze pollution, and focus on an... Rare and consecutive high-nitrate haze pollution episodes were observed in Beijing in spring2012. We present detailed characterization of the sources and evolutionary mechanisms of this haze pollution, and focus on an episode that occurred between 15 and 26 April. Submicron aerosol species were found to be substantially elevated during haze episodes, and nitrates showed the largest increase and occupation(average: 32.2%) in non-refractory submicron particles(NR-PM1), which did not occur in other seasons as previously reported. The haze episode(HE) was divided into three sub-episodes, HEa, HEb, and HEc. During HEa and HEc, a shallow boundary layer, stagnant meteorological conditions, and high humidity favored the formation of high-nitrate concentrations, which were mainly produced by three different processes —daytime photochemical production, gas-particle partitioning, and nighttime heterogeneous reactions — and the decline in visibility was mainly induced by NR-PM1.However, unlike HEa and HEc, during HEb, the contribution of high nitrates was partly from the transport of haze from the southeast of Beijing — the transport pathway was observed at ~800–1000 m by aerosol Lidar —and the decline in visibility during HEb was primarily caused by PM(2.5). Our results provide useful information for air quality improvement strategies in Beijing during Spring. 展开更多
关键词 Haze Nitrate Sources Lidar Aerosol Chemical Speciation Monitor Boundary layer
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