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Sustainable Agriculture Reviews 60 1

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丛书名： Sustainable Agriculture Reviews

1000年

作者： N.K. Singh Anirudha Chattopadhyay Eric Lichtfouse

ISBN: (数字)9783031241819

ISBN: (纸本)9783031241802;9783031241833

In the context of rising adverse effects of climate change on agriculture, there is a need for advanced methods and practices to manage soils for production of food and energy. This book presents the latest advances in microbial processes that control plant growth, with focus on genomic tools, microbial interactions with the plant and soils habitats, mobilization of plant nutrients, agricultural waste management, biodegradation, bioremediation, carbon sequestration, land reclamation, plant growth promotion, suppression of plant pathogens, induced systemic resistance and tolerance against biotic and abiotic stresses.

关键词： Agriculture Microbial Ecology Microbial Ecology

Rotor Dynamic Analysis of Supercritical Carbon Dioxide Bryton Cycle Coaxial Integrated Unit

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Rotor Dynamic Analysis of Supercritical Carbon Dioxide Bryto...

Prognostics and System Health Management Conference (PHM-Qingdao)

作者： Xiaokang Xu Yi Yang Jiangfeng Wang Juwei Lou Liangqi Chen State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an China Laboratory of Science and Technology on Integrated Logistics Support College of Intelligence Science and Technology National University of Defense Technology Changsha China

The rotor system plays a very important role in supercritical carbon dioxide Brayton cycle system, and its dynamic problem will directly affect the motion stability and safety of the whole unit. In this paper, the rotor dynamic model of supercritical CO 2 coaxial unit is established by finite element method, and the critical speed, modal shape and unbalance response of the rotor are studied. The first seven critical speed of the rotor and the first seven natural frequency of the rotor at the working speed are calculated. The bending modal of the rotor and the position where the rotor amplitude is the largest are analyzed, which can provide reference for the optimization design of the rotor stability. The influences of mass unbalances at the operational speed of rotor are analyzed. The research can provide some suggestions for the optimal design and actual operation of the supercritical CO 2 coaxial integrated unit.

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Synchronized Measurement Method of Burning Rate and Combustion Temperature of Solid Propellant Specimen

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SSRN 2023年

作者： Ni, Hu Fan, Rong Hu, Haihang Yang, Bin Wang, Zhixin Cao, Di Yang, Yang Shi, Zhiquan School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Space Propulsion Technology Research Institute Shanghai201109 China

To characterize solid propellant combustion, the measurement method of burning rate and combustion temperature of solid propellant specimen is developed that simultaneously combines shadow and radiation imaging methods. Shadow and radiation images of solid propellant specimen combustion are simultaneously captured by using light splitting and wavelength filtering imaging measurement system. Burning rate and combustion temperature of solid propellant specimen are synchronized obtained by burning surface identification and radiation image temperature measurement algorithm. Measurement accuracies of burning rate and combustion temperature of solid propellant specimen are validated by other independent measurement methods. Compared with target-line measurement method, the burning rate measurement relative deviation is less than 3.1%. Compared with thermocouple measurement, the temperature measurement relative deviation is less than 1.7%. On this basis, the synchronized measurements of burning rate and combustion temperature of different formulations of solid propellant specimens under different working conditions are carried out. The results show that burning rate and combustion temperature are important characterization parameters of solid propellant combustion performance. For a certain formula solid propellant specimen, the burning rate can be greatly increased by increasing the pressure, but the combustion temperature is not much increased. Therefore, the synchronized measurement of burning rate and combustion temperature can provide more direct data support for the evaluation of solid propellant combustion performance. © 2023, The Authors. All rights reserved.

关键词： Solid propellants

Design and Simulation of a New Type of Fin-and-Tube Heat Exchanger with Trapezoidal Slit Fins

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SSRN 2024年

作者： Zhang, Tianjiao Su, Mengyang Zhang, Hua Liu, Chuang Ouyang, Xinping School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China Key Laboratory of Thermo-Fluid Science and Engineering Ministry of Education Xi’an Jiaotong University Xi’an710049 China

Slit fin-and-tube heat exchangers are extensively utilized in industry, and optimizing the fin structure is conducive for improving energy efficiency and reducing energy losses. Therefore, a heat exchanger featuring trapezoidal slit fins was proposed in this study. To determine the structure of the slit fins, physical and mathematical models of the heat exchanger with a fin spacing Fp of 2.65 mm were established. We used a numerical simulation to investigate the structural parameters of the fin-and-tube heat exchanger, including the slit height Sh, slit width Sw, transverse tube spacing Pt, and longitudinal tube spacing Pl. Based on the simulation results, the effects of the four structural parameters on the comprehensive performance were evaluated. Additionally, the optimal parameter combination was determined through an orthogonal test, resulting in the following values: Sh = 1.47 mm, Sw = 4 mm, Pt = 42 mm, and Pl = 27.5 mm. This study provides significant theoretical and practical guidance. © 2024, The Authors. All rights reserved.

关键词： Energy dissipation

Stability and Emission Characteristics of Ammonia/Air Premixed Swirling Flames with Rotating Gliding Arc Discharge Plasma

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SSRN 2022年

作者： Ju, Rongyuan Wang, Jinhua Zhang, Meng Mu, Haibao Zhang, Guanjun Yu, Jinlu Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical Engineering Xi’an Jiaotong University Xi’an710049 China School of Aeronautics Engineering Air Force Engineering University Xi’an710038 China

Ammonia received increased attention as a carbon-free fuel and hydrogen carrier. Poor combustion stability and high NOx emission are the main issue for ammonia combustion. Effects of rotating gliding arc (RGA) discharge plasma on the flame stability and NOx emission of NH3/air premixed swirling flames were investigated. The discharge characteristics of the RGA were studied. The flame stabilization mechanisms by plasma were revealed and analyzed according to the flame structure transition and the distribution of key intermediate OH radicals. The NOx emissions were measured by the Gasmet DX4000 Fourier Transform Infrared (FTIR) gas analyzer. Results showed that the RGA discharge plasma can enhance the stability and extend the lean blow-off (LBO) limits from 0.6 to approximately 0.43-0.57. A hysteresis phenomenon about the transition between the lift-off flame and the attached flame was observed without plasma and disappeared with plasma activation. The plasma reduces NO and NO2 emissions mainly due to the kinetic and cracking effects of plasma. Extremely low NO emission below 300 ppm can be observed for very lean ammonia flames with an equivalence ratio (f) lower than 0.6, which are stabilized by plasma, while a large amount of unburned NH3 emission is accompanied. © 2022, The Authors. All rights reserved.

关键词： Ammonia

Influence of Bentonite on Copper Corrosion in Simulated Repository Electrolyte

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SSRN 2024年

作者： Ning, Zhiyuan Zhou, Qulan Li, Na Macdonald, Digby D. State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Departments of Nuclear Engineering and Materials Science and Engineering University of California at Berkeley BerkeleyCA94720 United States

The impact of bentonite on the corrosion of oxygen-free copper (OF-Cu) and oxygen-free phosphorous copper (OFP-Cu) in prototypical groundwater environments (standard reference electrolyte, SRE) simulating the storage of copper High-Level Nuclear Waste (HLNW) cannisters in granitic rock repositories is explored. At low corrosion potentials (-0.1VSCE), bentonite suppresses copper corrosion in SRE through the anion-exclusion effect, with its inhibitory impact intensifying at higher bentonite concentrations. As the corrosion potential rises, bentonite’s enhanced adsorption of metal cations increases the corrosion current. Additionally, bentonite hydrolysis producing silicate ions that accelerates pitting corrosion, culminating in passive film breakdown. This dual mechanism may amplify intergranular corrosion. In environments where bentonite exacerbates corrosion, OFP-Cu demonstrates superior corrosion resistance, though the introduction of phosphorus may influence the acceleration of intergranular corrosion following passivity breakdown. © 2024, The Authors. All rights reserved.

关键词： Bentonite

Pani Grafted Onto Waste Poros Polyurethane for Co-Adsorption of Multiple Pollutants in Industrial Wastewater

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SSRN 2023年

作者： Wang, Ning Guo, Yirui Song, Yi Yan, Wei Gong, Xuesong Li, Yunfeng Mu, Ruihua Liu, Yonghong Zhang, Luohong School of Environmental and Chemical Engineering Xi'an Polytechnic University Xi'An710048 China Department of Environmental Science and Engineering State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'An710049 China

Up-taking the pollutants simultaneously from industrial wastewater is an urgent in the advanced treatment. In this work, the polyaniline (PANI)-based efficient adsorbent supported by the waste polyurethane(PU) was designed for synchronous adsorption of pollutants (acid red G (ARG), methylene blue (MB), hexavalent chromium Cr(VI), phosphorus (TP), NH4+-N (ammonia nitrogen), NO3-N (nitrate nitrogen) and COD (chemical oxygen demand)). The results showed that the synchronous removal efficiency of ARG, MB, Cr(VI), TP, NH4+-N, NO3-N and COD in simulated wastewater reached 88%, 40%, 90%, 58%, 42%, 30% and 63%, respectively. The adsorption lasted for 1800 min (144 columns) before saturation, and no significant decrease was observed after 5 cycles of regeneration. Combined with the XPS (X-ray photoelectron spectroscopy) and EEM (excitation-emission matrix spectroscopy) analysis, ARG, Cr(VI), NO3-N and TP competed for the same adsorption sites, and the adsorption affinity order was ARG>Cr(Ⅵ)>TP>NO3-. During the adsorption process, Cr(VI) and =N- in PANI chain underwent redox reaction to form Cr(III) and -NH+-, which further promoted the adsorption of anionic pollutants, like H2PO4-. Redox reactions also occurred between Cr(VI) and MB before adsorption forming Cr(III) and small organic fragments. These conclusions prove the feasibility and effectiveness of PU-P/T as a potential engineering adsorbent for co-adsorption of a variety of pollutants. © 2023, The Authors. All rights reserved.

关键词： Adsorption

Influence of Bentonite on Copper Corrosion in Simulated Repository Electrolyte

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SSRN 2024年

The impact of bentonite on the corrosion of oxygen-free copper (OF-Cu) and oxygen-free phosphorous copper (OFP-Cu) in prototypical groundwater environments (standard reference electrolyte, SRE) simulating the storage of copper High-Level Nuclear Waste (HLNW) cannisters in granitic rock repositories is explored. At low corrosion potentials (-0.1V), bentonite suppresses copper corrosion in SRE through the anion-exclusion effect, with its inhibitory impact intensifying at higher bentonite concentrations. As the corrosion potential rises, particularly beyond the "bell-shaped" region in the polarization curve, bentonite's enhanced adsorption of metal cations increases the corrosion current. Additionally, bentonite hydrolysis producing silicate ions that accelerates pitting corrosion, culminating in passive film breakdown. This dual mechanism may amplify intergranular corrosion. In environments where bentonite exacerbates corrosion, OFP-Cu demonstrates superior corrosion resistance, though the introduction of phosphorus may influence the acceleration of intergranular corrosion following passivity breakdown. © 2024, The Authors. All rights reserved.

关键词： Copper corrosion

Effect of Fuel System on the Heat Releasing Method and flow-Path Design of Rocket-Based Combined Cycle Engine

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Effect of Fuel System on the Heat Releasing Method and Flow-...

International Conference on Mechanical and Aerospace engineering (ICMAE)

作者： Xiao Liu Yinhu Wang Yiyan Yang Lei Shi Dekun Yan State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China Beijing Institute of Long March Vehicle Beijing China Science and Technology on Combustion Internal Flow and Thermal-structure Laboratory Northwestern Polytechnical University Xi’an China

Multi-components rocket-based combined cycle (RBCC) engine is widely applied in most two-stage-to-orbit program due to stable operation performance under variable flight conditions. Present researches numerically compared RBCC’s performance under ramjet mode and scramjet mode, respectively, by using two fuel system, hydrogen and kerosene together with a $\mathrm{k}-\omega$ SST turbulence model. Researches showed that the combustor area ratio should be increased to keep stable pressure difference balance between inflow and flame because of higher caloric value using hydrogen. Distributed heat addition method is benifit for overall performance improvement when using hydrogen. Different from using kerosene, head should be delayedly added in combustor downtream under scramjet mode. Moreover, the advanced heat addition amount should be decreased under ramjet mode to ensure effective isolator operation.

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