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Arbuscular mycorrhizal fungi reduce ammonia emissions under different land-use types in agro-pastoral areas

Pedosphere 2024年第2期34卷 497-507页

作者： Huaisong WANG Rui GUO Yibo TIAN Nan CUI Xinxin WANG Lei WANG Zhongbao YANG Shuying LI jixun GUO Lianxuan SHI Tao zhang Institute of Grassland Science Northeast Normal UniversityKey Laboratory of Vegetation EcologyMinistry of EducationJilin Songnen Grassland Ecosystem National Observation and Research StationChangchun 130024China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesKey Laboratory of Dryland AgricultureMinistry of AgricultureBeijing 100081China Mountainous Area Research Institute of Hebei Province Hebei Agricultural UniversityBaoding 071001China College of Agronomy Liaocheng UniversityLiaocheng 252059China The Key Laboratory of Plant Development and Environmental Adaptation Biology Ministry of EducationSchool of Life ScienceShandong UniversityQingdao 266237China Forestry and Grassland Bureau of Aohan Banner Chifeng 024005China

Ammonia(NH3)emissions,the most important nitrogen(N)loss form,always induce a series of environmental problems such as increased frequency of regional haze pollution,accelerated N deposition,and N eutrophication.Arbuscular mycorrhizal(AM)fungi play key roles in N cycling.However,it is still unclear whether AM fungi can alleviate N losses by reducing NH3emissions.The potential mechanisms by which AM fungi reduce NH_(3)emissions in five land-use types(grazed grassland,mowed grassland,fenced grassland,artificial alfalfa grassland,and cropland)were explored in this study.Results showed that AM fungal inoculation significantly reduced NH3emissions,and the mycorrhizal responses of NH3emissions were determined by land-use type.Structural equation modeling(SEM)showed that AM fungi and land-use type directly affected NH_(3)emissions.In addition,the reduction in NH_(3)emissions was largely driven by the decline in soil NH_(4)^(+)-N and pH and the increases in abundances of ammonia-oxidizing archaea(AOA)amoA and bacteria(AOB)amoB genes,urease activity,and plant N uptake induced by AM fungal inoculation and land-use type.The present results highlight that reducing the negative influence of agricultural intensification caused by land-use type changes on AM fungi should be considered to reduce N losses in agriculture and grassland ecosystems.

关键词： agricultural intensification grassland management functional genes plant N uptake N leaching N loss

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Design and development of the deep-rock in-situ condition-preserved coring calibration platform

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International Journal of Mining Science and Technology 2023年第11期33卷 1377-1395页

作者： Yihang Li Heping Xie Ru zhang Zetian zhang Zhilong zhang Heng Gao Wei Huang jixun zhang Jiming Gao Xin Ma Ruibing Xu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Deep Underground Engineering Sciences and Green Energy Shenzhen UniversityShenzhen 518060China School of Mechanical Engineering Sichuan UniversityChengdu 610065China Donghua Zhuoyue Technology Co. Ltd.Chengdu 611130China Special Equipment Safety Supervision Inspection Institute of Jiangsu Province Nanjing 210036China Inner Mongolia North Heavy Industries Group Co. Ltd.Baotou 014033China

To systematically validate and calibrate the theory and technology of the deep in-situ conditionpreserved coring, the in-situ conditions at different depths should be simulated, and the full-size coring tests should be carried out in this simulated environment. Therefore, a deep-rock in-situ conditionpreserved coring calibration platform was designed and developed. The self-tightening sealing structure and the quick-disassembly structure were designed on the basis of an innovative segmented nonuniformdiameter structure, which was a breakthrough from the traditional high-pressure vessel frame and was verified by finite element simulation and actual testing under extreme working conditions, respectively.To simulate the actual deep in-situ environment with a temperature of 150℃ and pressure of 140 MPa for a large Φ450 mm×H1400 mm core, temperature and pressure control systems were designed by coupling, and a pre-embedded high-pressure-resistant temperature sensor was designed. Finally, highprecision assembly automation, complex movement coordination of the coring device with the platform,and rotary dynamic sealing were achieved by utilizing the combination of adaptive cabin body servo control and an adaptive mechanical structure in a limited space, laying a solid foundation for the calibration of in-situ condition-preserved coring.

关键词： In-situ condition-preserved coring calibration Deep Earth science Coring simulation Rotary dynamic seal

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Off-stoichiometry-guided design of high-strength chemically complex intermetallic-based alloys with outstanding ductility

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Journal of Materials Science & Technology 2023年第29期160卷 28-33页

作者： Bo Xiao jixun zhang Shaofei Liu Yilu Zhao Lianyong Xu C.T.Liu Tao Yang Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Center for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong KongChina Hong Kong Institute for Advanced Study City University of Hong KongHong KongChina School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Tianjin UniversityTianjin 300350China

1.Introduction The lasting drive for improved energy efficiency in power gen-eration encourages the innovative design of advanced structural materials with superb mechanical properties[1-6].Among these materials,ordered intermetallic alloys[7-9],as a unique class of metallic materials,have drawn increasing concern from both the scientific and industrial communities due to their intriguing high-temperature properties,strong chemical binding,and low atomic mobility[10,11].However,in light of the insufficient number of slip systems and/or intrinsically weak grain boundary(GB),they are usually brittle at ambient temperature,severely hindering their practical use in engineering systems[12].Previous studies reported that the change in alloy stoichiometry has a significant beneficial effect on the ductility of intermetallic alloys.For instance,Liu et al.

关键词： intermetallic ductility alloys

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An improved form of smoothed particle hydrodynamics method for crack propagation simulation applied in rock mechanics

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International Journal of Mining Science and Technology 2021年第3期31卷 421-428页

作者： Shuyang Yu Xuhua Ren jixun zhang Haijun Wang Zhaohua Sun College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology-Water Resource and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China School of Transportation and Civil Engineering Nantong UniversityNantong 226019China

The simulation of crack propagation processes in rock engineering has been not only a research hot spot among scholars but also a challenge.Based on this background,a new numerical method named improved kernel of smoothed particle hydrodynamics(IKSPH)has been put forward.By improving the kernel function in the traditional smoothed particle hydrodynamics(SPH)method,the brittle fracture characteristics of the base particles are realized.The particle domain searching method(PDSM)has also been put forward to generate the arbitrary complex fissure networks.Three numerical examples are analyzed to validate the efficiency of IKSPH and PDSM,which can correctly reveal the morphology of wing crack and the laws of crack coalescence compared with previous experimental and numerical studies.Finally,a rock slope model with complex joints is numerically simulated and the progressive failure processes are exhibited,which indicates that the IKSPH method can be well applied to rock mechanics engineering.The research results showed that IKSPH method reduces the programming difficulties and avoids the traditional grid distortion,which can provide some references for the application of IKSPH to rock mechanics engineering and the understanding of rock fracture mechanisms.

关键词： IKSPH Kernel function Crack propagation Fracture mechanics Numerical simulation

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冻结作用下土石坝护坡土石混合体水分迁移试验研究

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岩土工程学报 2024年第5期46卷 959-967页

作者：李卓姜鑫张继勋赵昱王虞清鲁洋南京水利科学研究院大坝安全与管理研究所江苏南京210029 水利部大坝安全管理中心江苏南京210029 河海大学水利水电学院江苏南京210024

土石坝护坡冻胀破坏主要由护坡砂砾料垫层、坝体填土自身冻胀和水分迁移共同作用引起。针对寒区土石坝护坡普遍存在的隆起、错位、坍塌等冻胀破坏问题,以寒区某土石坝护坡工程砂砾料垫层、坝体填土为研究对象,采用自研的土石混合体水分... 详细信息

土石坝护坡冻胀破坏主要由护坡砂砾料垫层、坝体填土自身冻胀和水分迁移共同作用引起。针对寒区土石坝护坡普遍存在的隆起、错位、坍塌等冻胀破坏问题,以寒区某土石坝护坡工程砂砾料垫层、坝体填土为研究对象,采用自研的土石混合体水分迁移冻结模型试验装置系统,开展了补水条件下单向冻结模型试验研究,研究了温度、含石量、水分迁移对土石坝护坡土石混合体冻胀特性的影响。研究结果表明:温度、含石量对土石混合体的冻胀特性影响显著;水分迁移受土石含量、温度和含水率影响,护坡砂砾料垫层和坝体填土含水率越大,冻结过程中水分迁移量越大,水分相变成冰的条件越充分;土、石分层对黏土温度变化影响较大,黏土和砾石分层可有效减小水分迁移量和冻胀量,对土石坝护坡防冻胀是有利的;土石混合体内部孔隙水相变成冰并在试样内部形成分凝冰是冻胀量增加的主要原因,土石混合体原位冻胀以及冻结过程中分凝冰的生长使冻胀量不断增加,且补水量越大,试样冻胀量就越大;不同温度、含石量下试样的冻胀量均随补水量的增加而基本呈线性增大,且含石量对冻胀量增加速率影响较小,温度对冻胀量增加速率影响较显著。研究成果可为寒区土石坝护坡设计和运行管理提供科学依据和技术支撑,补充了碾压式土石坝设计规范中的护坡设计。

关键词：土石坝土石混合体水分迁移冻胀破坏冻结作用

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Excellent shape recovery characteristics of Cu-Al-Mn-Fe shape memory single crystal

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Journal of Materials Science & Technology 2020年第22期54卷 43-50页

作者： Shuiyuan Yang Lipeng Guo Xinyu Qing Shen Hong jixun zhang Mingpei Li Cuiping Wang Xingjun Liu College of Materials and Fujian Key Laboratory of Materials Genome Xiamen UniversityXiamen361005China State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology UniversityShenzhen518055China

Shape memory alloys can recover the deformed shape due to their superelasticity or shape memory effect. In this study, a novel Cu-Al-Mn-Fe shape memory single crystal is reported. The results show that it has excellent superelasticity and shape memory effect simultaneously when deformed at room temperature, as well as tunably wide response temperature range with near-zero interval of reverse phase transformation. When deforming one single crystal at room temperature, it not only possesses full superelasticity of 7%, but also tunable shape memory effects up to 8.8 %. The full shape recovery during heating exhibits near-zero response interval and tunably wide response temperature range of 166 K depending on the deformation. The functional characteristics of the alloys result from the controllable reverse phase transformation hinging on the stabilization of stress-induced martensite. This class of Cu-Al-Mn-Fe alloy may be used as both superelastic materials, and shape memory materials with wide working temperature range as high-sensitive detector, driver or sensor.

关键词： Shape memory alloys Superelasticity Martensite stabilization Shape memory effect Nanoparticles

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Role of β(FeAl) nanoparticles in abnormal grain growth in the annealing of cast Cu-Al-Mn-Fe shape memory alloys

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Progress in Natural Science:Materials International 2020年第4期30卷 510-516页

作者： Shuiyuan Yang Xinyu Qing jixun zhang Lipeng Guo Shen Hong Mingpei Li Jinbin zhang Cuiping Wang Xingjun Liu College of Materials of Xiamen University Shenzhen Research Institute of Xiamen University Fujian Key Laboratory of Materials Genome Xiamen University State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology University

In this study, the low-cost production of Cu-Al-Mn-Fe shape memory alloy single crystals exceeding 46 mm by abnormal grain growth was realized only through annealing their cast alloys. The results show that the misorientation formed during annealing may be responsible for such abnormal grain growth process. It was confirmed that this misorientation resulted from the dissolution of bcc β(Fe Al) nanoparticles during heat treatment at a sufficiently temperature of approximately 1173 K. The rate of migration of the abnormal grain boundary was experimentally measured to be approximately 9.3 × 10-5m s-1within 2 min of the commencement of abnormal grain growth. Additionally, the range of composition of the alloys that can lead to abnormal grain growth was determined. When the Cu-13.0 Al-6.5 Mn-3.2 Fe single crystal close to the [100] direction was deformed to a prestrain of 12%, full shape recovery happened without any residual strain. At that time, the superelastic strain was approximately 9%. Such a superelastic characteristic remained nearly constant over 50 cycles, showing excellent fatigue resistance. The superelastic properties of the present Cu-13.0 Al-6.5 Mn-3.2 Fe single crystal are compared to those of commercial Ni-Ti-based shape memory alloys. Therefore, it can be considered as a new kind of superelastic material having practical applications. The obtained results should be of great significance in the development of Cu-based shape memory alloys. Furthermore, it is expected that a similar microstructure can be designed for the production of more metallic single crystals.

关键词： Shape memory alloys Superelasticity Abnormal grain growth Nanoparticles Dissolution

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考虑宏微观几何形貌的螺栓连接结合面接触性能模型

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西安交通大学学报 2024年第7期58卷 148-159页

作者：朱林波梁洪瑀张瀚文史继勋洪军西安交通大学化学工程与技术学院西安710049 西安交通大学现代设计及转子轴承系统教育部重点实验室西安710049

为准确预测螺栓连接结合面的真实接触状态,提出了考虑宏微观几何形貌的螺栓连接结合面接触性能模型。通过小波分解方法,解决了实测螺栓连接结合面粗糙表面提取与重构的问题。采用两粗糙表面接触等效、数据驱动建模、宏微观变网格划分等... 详细信息

为准确预测螺栓连接结合面的真实接触状态,提出了考虑宏微观几何形貌的螺栓连接结合面接触性能模型。通过小波分解方法,解决了实测螺栓连接结合面粗糙表面提取与重构的问题。采用两粗糙表面接触等效、数据驱动建模、宏微观变网格划分等技术,构建了考虑微观形貌与宏观几何尺寸耦合的螺栓连接结合面跨尺度模型,实现了结合面接触性能的准确计算。通过压力薄膜传感器测量被连接件结合面的压力分布,验证了计算模型的正确性,并以此为基础系统分析了被连接件厚度、螺栓预紧力以及螺栓规格尺寸对结合面接触性能的影响。计算结果表明:螺栓连接结合面真实压力分布具有非连续性,结合面压力最大值并非在被连接件孔径边缘处,而是在孔径与螺栓头外径之间;结合面真实接触面积远小于名义接触面积;结合面真实压力分布范围随着被连接件厚度、螺栓预紧力、螺栓规格尺寸的增加而增加,厚度和预紧力的影响呈现明显的非线性,螺栓尺寸的影响呈现一定的线性规律,且斜率为0.37。研究结果可为刚度、阻尼、密封等机械装备装配性能的可靠评估提供支撑。

关键词：接触性能粗糙表面跨尺度模型螺栓连接

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土石坝护坡冻胀破坏水-热-力耦合数值模拟研究

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水利水运工程学报 2024年第3期 136-145页

作者：李卓姜鑫张继勋赵昱王虞清方艺翔南京水利科学研究院江苏南京210029 水利部大坝安全管理中心江苏南京210029 河海大学水利水电学院江苏南京210098

针对寒区土石坝护坡普遍存在的冻胀破坏问题,选取寒区某土石坝工程为研究对象,结合土石坝工程特点,建立考虑水-热-力耦合作用的有限元计算模型。研究护坡在库水位和坝体填土水分迁移作用下冻胀破坏全过程,分析土石坝温度场、水分场和位... 详细信息

针对寒区土石坝护坡普遍存在的冻胀破坏问题,选取寒区某土石坝工程为研究对象,结合土石坝工程特点,建立考虑水-热-力耦合作用的有限元计算模型。研究护坡在库水位和坝体填土水分迁移作用下冻胀破坏全过程,分析土石坝温度场、水分场和位移场的变化规律,并将位移场有限元计算结果与实测冻胀变形资料进行对比,验证有限元计算结果。研究结果表明:冻胀作用对坝坡影响深度约为2 m,坝坡浅层0~2 m范围的温度变化受外界气温影响较大,坝体内部温度相对坝坡浅层变幅小,且有一定的滞后性;负温使坝坡浅层孔隙水相变成冰,宏观上表现为未冻水体积分数的降低,坝坡浅层土石混合体孔隙水相变、坝体填土内水分向坝坡迁移和冻结峰面向坝体内部移动是护坡冻胀破坏的主要因素;大坝坝坡计算冻胀量为20~30 cm,最大值为36 cm,计算结果与实测冻胀变形资料吻合;护坡冻胀破坏主要由砂砾料垫层、坝体填土等土石混合体冻胀及冰推力共同作用引起。研究结果可为寒区土石坝护坡设计提供参考。

关键词：土石坝护坡冻胀破坏水-热-力耦合寒区

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显式算法中三维黏弹性人工边界应用及输水隧洞动力响应分析

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水力发电 2024年第1期50卷 20-25,70页

作者：陈旻铭任旭华张继勋河海大学水利水电学院江苏南京210024

为确保大型复杂三维有限元模型动力响应分析的稳定性及高效性,结合二维黏弹性边界理论及其在动力显式分析中稳定性的改善方法,提出了一种适用于ABAQUS/Explicit模块的三维黏弹性人工边界方法,并依托某输水隧洞与临近高铁隧道的立交工程... 详细信息

为确保大型复杂三维有限元模型动力响应分析的稳定性及高效性,结合二维黏弹性边界理论及其在动力显式分析中稳定性的改善方法,提出了一种适用于ABAQUS/Explicit模块的三维黏弹性人工边界方法,并依托某输水隧洞与临近高铁隧道的立交工程,在设有三维黏弹性边界的基础上研究高速列车振动荷载对既有水工隧洞的振动影响特性。结果表明,采用动力显式分析时,稳定性改善后的黏弹性人工边界具有良好的吸能效果,满足远域地基的回弹性能;振动荷载对输水隧洞的动力影响随着作用距离的增大而减小,且各断面的动力响应极值均出现在底板中心。

关键词：输水隧洞动力响应黏弹性人工边界三维有限元显式算法

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