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Changes in soil quality under different agricultural management in Chinese mollisols.
Mollisols (called Black soils) are of major agricultural importance in China. Most of these soils have been used agriculturally for the last 50 years or so. Due to intensive cultivation and improper soil management, loss of organic matter and yield suppression resulting from soil erosion are serious problems in the region. The current research studied the physical and chemical properties of a typical Mollisol in China, characterized the changes of soil organic carbon (SOC) with cultivation, investigated the effects of agricultural management systems on SOC and total organic nitrogen (TON) contents and their vertical distribution, and examined the negative impacts of continuous soybean on crop and soil productivity. The soil is characterized with a thick (60 cm) mollic epipedon, higher organic carbon (5.8%), CEC (43.7 cmol(+)/kg) and macro-aggregate (\u3e0.25 mm) stability, and greater macronutrients and water availability in the upper epipedon. Bulk density increases with depth, and total porosity declines with depth. Soil texture is clay loam. Overall characteristics make this soil fertile and productive. The SOC content declined rapidly at early years of cultivation and gradually afterwards. Compared with organic matter in the uncultivated soil, total SOC loss was 17%, 28%, and 55% in 5-, 14- and 50-year cultivation, respectively. Wheat-soybean rotation with addition wheat straw or pig manure resulted in a substantial increase in SOC content in 9 years. Compared with a wheat-corn-soybean rotation, continuous cropping reduced SOC and N contents in the profile, particularly SOC content. Moldboard plowing significantly reduced SOC and N contents whereas integrated tillage increased SOC and N relative to conventional tillage. Use of chemical fertilizers (N, P, and K) along with return of crop residues resulted in a substantial increase in SOC and N in top layers of the soil. Continuous soybean results in unbalanced soil enzymes activities, declines of SOC, total K, Zn, available K and N contents, soil pH and bacteria/fungi ratio. It is proposed that the best management for maintaining soil productivity in the area would be crop rotation along with the integrated tillage and addition of crop residues and chemical fertilizers
Occurrence and Control of Soybean Aphid, Aphis glycines Matsumura
The soybean aphid, Aphis glycines Matsumura, is one of the most important pests of soybean. The A. glycines outbreak in 1998 followed another aphid outbreak after 1989, which caused enormous economic losses. The aphid infested areas exceeded 200 thousand mu, and the soybean yields decreased by 20%. Among aphid infested areas, 78 thousand mu were severely infested with a yield loss of 46%. More than 3,000 mu had no yield at all.Originating text in Chinese.Citation: Wu, Xiaobing, Ni, Wenjun, Liu, Peijing. (1999). Occurrence and Control of Soybean Aphid, Aphis glycines Matsumura. How Peasants Can Increase Wealth, 6, 20
Understanding and Improving Recurrent Networks for Human Activity Recognition by Continuous Attention
Deep neural networks, including recurrent networks, have been successfully
applied to human activity recognition. Unfortunately, the final representation
learned by recurrent networks might encode some noise (irrelevant signal
components, unimportant sensor modalities, etc.). Besides, it is difficult to
interpret the recurrent networks to gain insight into the models' behavior. To
address these issues, we propose two attention models for human activity
recognition: temporal attention and sensor attention. These two mechanisms
adaptively focus on important signals and sensor modalities. To further improve
the understandability and mean F1 score, we add continuity constraints,
considering that continuous sensor signals are more robust than discrete ones.
We evaluate the approaches on three datasets and obtain state-of-the-art
results. Furthermore, qualitative analysis shows that the attention learned by
the models agree well with human intuition.Comment: 8 pages. published in The International Symposium on Wearable
Computers (ISWC) 201
Reduction of Amine Emissions from an Aqueous Amine Carbon Dioxide Capture System Using Charged Colloidal Gas Aphrons
The present invention includes a system and process to reduce amine mist emissions (or MEA) from carbon capture systems using colloidal gas aphrons (CGA), and includes a method for separating and recovering an amine solvent (e.g., in the form of entrained droplets/mist and/or fine aerosol particles) from a carbon dioxide scrubbed flue gas stream exiting a carbon capture system (e.g., oil-fired power plants, coal-fired power plants, and/or natural gas combined cycle plants)
Unravelling the Correlation of Electronic Structure and Carrier Dynamics in CuInS\u3csub\u3e2\u3c/sub\u3e Nanoparticles
In this work, we report the direct correlation of photoinduced carrier dynamics and electronic structure of CuInS2 (CIS) nanoparticles (NPs) using the combination of multiple spectroscopic techniques including steady-state X-ray absorption spectroscopy (XAS), optical transient absorption (OTA), and X-ray transient (XTA) absorption spectroscopy. XAS results show that CIS NPs contain a large amount of surface Cu atoms with ≪four-coordination, which is more severe in CIS NPs with shorter nucleation times, indicating the presence of more Cu defect states in CIS NPs with smaller size particles. Using the combination of OTA and XTA spectroscopy, we show that electrons are trapped at states with mainly In or S nature while holes are trapped in sites characteristic of Cu. While there is no direct correlation of ultrafast trapping dynamics with NP nucleation time, charge recombination is significantly inhibited in CIS NPs with larger particles. These results suggest the key roles that Cu defect sites play in carrier dynamics and imply the possibility to control the carrier dynamics by controlling the surface structure at the Cu site in CIS NPs
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