Influence of Planting Density on Root Spatio-Temporal Distribution of Different Types of Maize under High-Yielding Cultivation Conditions

2013 ◽  
Vol 38 (7) ◽  
pp. 1286-1294 ◽  
Author(s):  
Zong-Xin LI ◽  
Yuan-Quan CHEN ◽  
Qing-Cheng WANG ◽  
Kai-Chang LIU ◽  
Wang-Sheng GAO ◽  
...  
2012 ◽  
Vol 65 (3) ◽  
pp. 2077-2103 ◽  
Author(s):  
Chen-Yuan Chen ◽  
Tsung-Hao Chen ◽  
Ying-Hsiu Chen ◽  
Chieh-Lian Chen ◽  
Shang-En Yu

2021 ◽  
Vol 14 (3) ◽  
pp. 1220
Author(s):  
Maíra Iaê Savioli Rocha ◽  
Diego Tarley Ferreira Nascimento

Usualmente empregadas pelos povos tradicionais, as queimadas também têm sido utilizadas para o desmatamento de vegetação natural e incorporação de atividades agropecuárias. Diante desse contexto, tem-se como objetivo analisar a distribuição espaço-temporal dos focos de queimadas no bioma Cerrado no período de 1999 a 2018, verificando sua ocorrência entre os diferentes tipos de cobertura e uso do solo, no intuito de avaliar a hipótese de que a prática de queimadas esteja recorrentemente associada à desmatamentos e à implantação de atividades agropecuárias. Para tanto, foram compilados, organizados e processados em ambiente SIG, arquivos vetoriais de focos de queimadas, a partir do Banco de Dados de Queimadas (BDQ/INPE), e arquivos raster de mapeamentos de cobertura e uso do solo do Cerrado, elaborados e disponibilizados pelo Projeto MapBiomas, ambos dados referente ao bioma Cerrado e ao recorte temporal de 1999 a 2018. Em termos médios, verifica-se a ocorrência de 65.513 focos anuais de queimadas, porém, em alguns anos a quantidade de queimadas atinge o montante de 137.918 focos, como visto em 2007. Há uma concentração das queimadas no período seco, especialmente, no trimestre agosto-setembro-outubro, que responde por 72% das ocorrências anuais. A maior densidade de queimadas é percebida ao longo da fronteira agrícola na região do MATOPIBA e próxima ao Arco do Desmatamento, nos estados do Maranhão, Tocantins e de Mato Grosso, ao passo que evidencia-se a maior incidência das queimadas sobre determinadas classes de cobertura e uso do solo, sobretudo representadas por formações savânicas e campestres.  Space-temporal distribution of fires in the Cerrado biome (1999/2018) and their occurence according to different types of coverage and soil uses A B S T R A C TUsually employed by traditional communities, fires have also been used to deforest and incorporate agricultural activities. Given this context, the objective is to analyze the spatio-temporal distribution of the fires in the Cerrado biome, from 1999 to 2018, verifying their occurrence between the different types of cover and land use, in order to assess the hypotheses that the practice of fires is recurrently associated with deforestation and the implementation of agricultural activities. For this purpose, were compiled, organized and processed in a GIS environment, fires focus from the Burn Database of the National Institute for Space Research and mappings of cover and land use, elaborated and availabled by the MapBiomas Project, both data referring to the Cerrado biome and over the years 1999 to 2018. On average, there are 65,513 annual fires, but in some years the amount of burns reaches the amount of 137,918 – as seen in 2007. There is a concentration of fires in the dry period, mainly in the August-September-October, which accounts for 72% of annual fires. The highest density of fires occurs mainly along the agricultural frontier in the MATOPIBA region and close to the Arc of Deforestation, specifically in the states of Maranhão, Tocantins and Mato Grosso, while there is a greater incidence of fires on certain classes of coverage and land use, especially represented by savanna and grassland formation, which corroborates the hypothesis of the use of fires to convert vegetation cover into anthropic uses.Keywords: Fires, Cerrado, Cover and land use.


2019 ◽  
Author(s):  
Rudra Mohan Pradhan ◽  
◽  
Karrie A. Weber ◽  
Karrie A. Weber ◽  
Daniel Snow ◽  
...  

2021 ◽  
Vol 13 (5) ◽  
pp. 892
Author(s):  
Xiaomei Li ◽  
Pinhua Xie ◽  
Ang Li ◽  
Jin Xu ◽  
Zhaokun Hu ◽  
...  

This paper studied the method for converting the aerosol extinction to the mass concentration of particulate matter (PM) and obtained the spatio-temporal distribution and transportation of aerosol, nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) based on multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations in Dalian (38.85°N, 121.36°E), Qingdao (36.35°N, 120.69°E), and Shanghai (31.60°N, 121.80°E) from 2019 to 2020. The PM2.5 measured by the in situ instrument and the PM2.5 simulated by the conversion formula showed a good correlation. The correlation coefficients R were 0.93 (Dalian), 0.90 (Qingdao), and 0.88 (Shanghai). A regular seasonality of the three trace gases is found, but not for aerosols. Considerable amplitudes in the weekly cycles were determined for NO2 and aerosols, but not for SO2 and HCHO. The aerosol profiles were nearly Gaussian, and the shapes of the trace gas profiles were nearly exponential, except for SO2 in Shanghai and HCHO in Qingdao. PM2.5 presented the largest transport flux, followed by NO2 and SO2. The main transport flux was the output flux from inland to sea in spring and winter. The MAX-DOAS and the Copernicus Atmosphere Monitoring Service (CAMS) models’ results were compared. The overestimation of NO2 and SO2 by CAMS is due to its overestimation of near-surface gas volume mixing ratios.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Randy Lemons ◽  
Wei Liu ◽  
Josef C. Frisch ◽  
Alan Fry ◽  
Joseph Robinson ◽  
...  

AbstractThe structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.


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