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37 results on '"Deng Yangwu"'

16. On the analysis of burst capacity of steel strip reinforced flexible pipe with swaging endfitting.

Author

Chen, Wei, Yan, Junwei, Wang, Youyi, Deng, Yangwu, and Bai, Yong

Subjects
STEEL strip, STRAINS & stresses (Mechanics), CYLINDRICAL shells, PIPE, STRESS concentration
Abstract

The objective of this paper is to study the burst capacity of steel strip reinforced flexible pipe (steel strip PSP) with swaging endfitting, in the situation that the burst point is in pipe-endfitting joint area. Experiment was conducted and an analytical model based on thin-wall cylindrical shell theory was proposed. Hoop stress in local coordinate on the innermost reinforcement layer is introduced to predict the burst strength of the pipe, as the hoop stress on this layer in pipe-endfitting joint area increases, the strain on the same layer in the area far away (x→∞) from endfitting is extracted and the corresponding internal pressure can be then obtained. Results of the theoretical model compare well with experimental data. Study shows that Diameter to thickness ratio of pipe (D/t ratio) may affect the SCE in pipe-endfitting joint area. Some useful conclusions are drawn for the design and application of steel strip PSP. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Legacy effect of elevated CO2and N fertilization on mineralization and retention of rice (Oryza sativaL.) rhizodeposit-C in paddy soil aggregates

Author

Li, Yuhong, Yuan, Hongzhao, Chen, Anlei, Xiao, Mouliang, Deng, Yangwu, Ye, Rongzhong, Zhu, Zhenke, Inubushi, Kazuyuki, Wu, Jinshui, and Ge, Tida

Abstract

Rhizodeposits in rice paddy soil are important in global C sequestration and cycling. This study explored the effects of elevated CO2and N fertilization during the rice growing season on the subsequent mineralization and retention of rhizodeposit-C in soil aggregates after harvest. Rice (Oryza sativaL.) was labeled with 13CO2under ambient (400 ppm) and elevated (800 ppm) CO2concentrations with and without N fertilization. After harvest, soil with labeled rhizodeposits was collected, separated into three aggregate size fractions, and flood-incubated for 100 d. The initial rhizodeposit-13C content of N-fertilized microaggregates was less than 65% of that of non-fertilized microaggregates. During the incubation of microaggregates separated from N-fertilized soils, 3%–9% and 9%–16% more proportion of rhizodeposit-3C was mineralized to 13CO2, and incorporated into the microbial biomass, respectively, while less was allocated to soil organic carbon than in the non-fertilized soils. Elevated CO2increased the rhizodeposit-13C content of all aggregate fractions by 10%–80%, while it reduced cumulative 13CO2emission and the bioavailable C pool size of rhizodeposit-C, especially in N-fertilized soil, except for the silt-clay fraction. It also resulted in up to 23% less rhizodeposit-C incorporated into the microbial biomass of the three soil aggregates, and up to 23% more incorporated into soil organic carbon. These results were relatively weak in the silt-clay fraction. Elevated CO2and N fertilizer applied in rice growing season had a legacy effect on subsequent mineralization and retention of rhizodeposits in paddy soils after harvest, the extent of which varied among the soil aggregates.

Published
2022
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31. Assessment of depth‐dependent microbial carbon‐use efficiency in long‐term fertilized paddy soil using an 18O–H2O approach.

Author

Zhran, Mostafa, Ge, Tida, Tong, Yaoyao, Deng, Yangwu, Wei, Xiaomeng, Lynn, Tin Mar, Zhu, Zhenke, Wu, Jinshui, and Gunina, Anna

Subjects
SOIL depth, FERTILIZERS, SOILS, DEFICIENCY diseases, PLANT competition, BIOMASS production
Abstract

Activity of microorganisms and their turnover strongly affect soil organic carbon (SOC) accumulation. However, what remains unclear is how long‐term fertilization affects the microorganisms growth strategies, and how they change with the soil depth. Thus, microbial carbon‐use efficiency (CUE) and microbial biomass (MB) turnover in paddy soil were determined using a novel substrate‐independent H218O labelling approach, and the effects of long‐term fertilization (>30 years) with mineral (NPK) or combined (NPK + OM [manure]) amendments in 0–10, 10–20, and 20–30 cm depths were investigated. Long‐term fertilization increased microbial C uptake, CUE, and growth rates, and all indexes were the highest in the NPK + OM treatment. The CUE ranged between 0.07 and 0.23 and showed variable behaviour with depth: it reduced in the control treatment, indicating that more C was allocated to energy production than biomass growth, and increased in fertilized soils, showing the shift of C usage for biomass growth. The highest CUE was observed at 20–30 cm in NPK and NPK + OM, and indicated that microorganisms overcome the nutrient deficiency in deep soil layers by keeping high C uptake rates at a constant CUE. The MB turnover was more rapid in NPK (70–10 d) and NPK + OM (65–40 d) compared to the control (80–90 d) and intensified with the depth. These findings highlight that the decrease in C uptake under long‐term fertilization with soil depth compensated by an increase in CUE. These shifts in the strategies of microorganisms functioning can explain the accumulation of SOC in heavily fertilized paddy soils. [ABSTRACT FROM AUTHOR]

Published
2021
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32. The 13C-CO2 pulsing labeling method: distribution of rice photosynthetic carbon in plant-soil systems during different rice growth stages

Author

Ge Tida, Tang Chun, Wang Jiurong, Wu Jinshui, Zou Guanfa, Yuan Hongchao, Ning Zhao, and Deng Yangwu

Subjects
0301 basic medicine, 03 medical and health sciences, Ecology, 030106 microbiology, 010501 environmental sciences, 01 natural sciences, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract

定量生育期内植物光合碳在植物组织-土壤的分配规律，对于理解全球碳循环有着重要意义。采用13C-CO2脉冲标记结合室内培养，通过元素分析仪-稳定同位素联用（Flash HT-IRMS）分析植物各部分及土壤δ13C值，比较了不同生育期下水稻光合碳在不同组织间的分配规律，并量化了水稻光合碳向土壤碳库的转移。结果表明：（1）水稻地上部和根系干物质量随水稻生育期的增加而呈现递增趋势，不同的生育期表现为：分蘖期>拔节期>抽穗期>扬花期>成熟期。而整个生育期的根冠比为0.2-0.4，分蘖期的根冠比最高，随着水稻生育期的增加而递减，到抽穗期以后根冠比稳定在0.2左右。（2）脉冲标记6h后，水稻地上部和地下部（根系）的δ13C值在-25.52‰——28.33‰，不同器官的δ13C值存在明显分馏效应，且趋势基本一致，即茎杆（籽粒）>叶片（根系）；这种由于水稻生育期特性导致的各器官碳同位素分馏的现象，可用于指示不同生育期下水稻光合碳的分配和去向。（3）不同生育期13C-光合碳在植物-土壤系统的分配规律不同，生长前期光合碳向根系及土壤中分配的比例高，具有较强的碳汇能力，而随生育期光合碳在根系及土壤中的分配比例呈下降趋势，但积累量不断增加。（4）不同生育期13C光合碳在水稻-土壤系统中的分配比例差异明显。水稻分蘖期有近30%光合碳用于根系建成并部分通过根系分泌物进入土壤有机碳库（10%），而到成熟期则向籽粒中分配较多，而且光合碳在土壤中的分配比例也随生育期呈下降趋势。研究结果对稻田土壤有机碳循环过程和调控机制的揭示具有重要的理论意义。

Published
2017

36. Promotion of the symbiotic interaction between phagotrophic protists and beneficial bacteria, mediated viaa balancing of soil nutrients, reduces the incidence of watermelon Fusarium wilt

Author

TONG, Yaoyao, WANG, Li, WU, Chuanfa, ZHANG, Haoqing, DENG, Yangwu, CHEN, Ming, ZHENG, Xianqing, LV, Weiguang, CHEN, Jianping, and GE, Tida

Abstract

Elucidating the microbial mechanisms that trigger Fusarium wilt represents a key step in addressing the barriers to sustainable cropping. However, from the perspective of the complete microbiome, the integrated role of soil nutrients and the microbial community in fields with different rate of wilt disease remains unclear. In this study, we examined the potential interrelationships among rhizosphere soil nutrients, bacteria, fungi, and protists in soils collected from fields in which watermelon had been cultivated for 8 years, and which were characterized by high (HW: 81.25%) or low (LW: 6.25%) incidence of watermelon Fusarium wilt. Soil from HW fields was found to contain a higher density of F. oxysporum(1.30-fold higher than that in the LW soil), along with higher contents of available phosphorus (1.31-fold higher), and available potassium (2.39-fold higher). In addition, the inter-kingdom correlation between protists and bacteria in the HW soil was 2.08-fold higher than that in LW soil. Furthermore, structural equation modeling revealed that an excess of soil available potassium enhances predation by potentially detrimental phagotrophic protists on potentially beneficial bacteria. Collectively, our findings indicate that a balanced nutrient input and the interaction between protists and beneficial bacteria play important roles in controlling the incidence of watermelon Fusarium wilt. These findings have implications for controlling the incidence of watermelon Fusarium wilt based on modifying the nutrient balance of soil and increasing the flora of certain beneficial protists (Cercomonasand Colpoda) that interact symbiotically with species of Bacillus.

Published
2024
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