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毛乌素典型固沙植物的水分利用特性与吸水机制

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应用生态学报 2024年第4期35卷 897-908页

作者：刘秀花周子怡贺屹马延东李丙祥郑策长安大学水利与环境学院西安710054 长安大学旱区地下水与生态效应教育部重点实验室西安710054 陕西省林业科学院西安710082 广东省惠州市惠东县花树下水库养护所广东惠州516300

了解固沙植物的吸水机制有利于合理设置植被群落结构,可为科学治沙和水资源高效利用提供依据。本研究基于降水-土壤水-植物木质部水-地下水的氢氧同位素组成,结合土壤水热和植被全年耗水特征,利用多源线性混合模型(IsoSource),分析了冬... 详细信息

了解固沙植物的吸水机制有利于合理设置植被群落结构,可为科学治沙和水资源高效利用提供依据。本研究基于降水-土壤水-植物木质部水-地下水的氢氧同位素组成,结合土壤水热和植被全年耗水特征,利用多源线性混合模型(IsoSource),分析了冬季和生长季典型沙地植物沙柳和沙蒿的水分来源差异,并探究了地下水位埋深(2和10 m)、土壤冻融和干旱对其水分利用的影响。结果表明:1)沙柳在土壤冻融期(1-3月)主要利用冻层下60~120 cm深度土壤水(69.1%);在返青季(4、5月)0~60 cm层土壤水可满足生长需求(30.9%~87.6%);在生长季的干旱期(6月)主要利用120~160 cm层土壤水(27.4%~40.8%);而在雨季(7、9月)0~60 cm层土壤水对其供水达到59.8%~67.9%。根系较浅的沙蒿在根区土壤完全冻结后无法利用土壤水,可通过秋季储存在根茎的水分越冬;而在生长季以利用0~40 cm层土壤水为主(23.4%~86.8%),在旱期主要利用40~80和80~160 cm层土壤水,利用率分别为14.6%~74.4%和21.8%~78.2%。2)随着地下水埋深的减小,植被吸取土壤水的深度上移,其中沙柳水分来源由120~160 cm层土壤水向60~160 cm层变化,而沙蒿的吸水深度从80~160 cm层变为0~40 cm层。沙柳对土壤水的利用受植物蒸腾的影响,会“按需取用”以达到供水与节能的平衡;沙蒿则偏向利用浅层土壤水,对单一土壤层位的水源依赖较高。

关键词：稳定同位素植物水分利用吸水来源地下水 IsoSource模型

脉冲激励下铁基纳米晶磁芯的Jiles-Atherton模型参数辨识及应用

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强激光与粒子束 2024年第6期36卷 129-137页

作者：江进波李毅曹宇蔡宛辰姚延东徐林三峡大学电气与新能源学院湖北宜昌443002 湖北省输电线路工程技术研究中心(三峡大学) 湖北宜昌443002 国网巢湖供电公司安徽巢湖238000 国网丹东供电公司辽宁丹东118000

通过理论分析对经典J-A方程进行了修正,增强了其在脉冲条件下的适应性,利用脉冲磁化特性实验平台,测量了铁基纳米晶磁芯在不同磁化速率下的磁滞回线,采用遗传算法进行脉冲激励下的J-A参数辨识,将算法模拟的磁滞回线与实验测试的磁滞回... 详细信息

通过理论分析对经典J-A方程进行了修正,增强了其在脉冲条件下的适应性,利用脉冲磁化特性实验平台,测量了铁基纳米晶磁芯在不同磁化速率下的磁滞回线,采用遗传算法进行脉冲激励下的J-A参数辨识,将算法模拟的磁滞回线与实验测试的磁滞回线数据集进行拟合,验证了修正后的J-A方程的有效性,最后将遗传算法寻优得到的J-A参数应用于脉冲变压器场路耦合模型的磁芯J-A参数定义中,分析脉冲变压器初级电压为1.5 kV时的仿真与实验误差,得到脉冲变压器输出波形的脉冲前沿误差为3.33%,幅值误差为2.91%,相比于J-A参数的常规非线性求解方法精度更高,能更好地应用于脉冲功率系统中含磁性元件的建模仿真。

关键词：铁基纳米晶脉冲磁化特性 Jiles-Atherton模型遗传算法脉冲变压器

黄土-古土壤原核生物群落对古气候变化的响应

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微生物学报 2024年第6期64卷 1800-1823页

作者：刘秀花孙钰涵卢杰刘小康马延东贺屹胡安焱长安大学水利与环境学院陕西西安710054 旱区地下水与生态效应教育部重点实验室陕西西安710054 陕西省土地工程建设集团有限责任公司陕西宝鸡721004 榆林市水利局河湖水库与移民工作中心陕西榆林719000 陕西省林业科学研究院国家林业局黄土高原水土保持与生态恢复重点实验室陕西西安710082

【目的】黄土-古土壤序列是记录第四纪气候环境变化的良好载体,其内部的土壤微生物特征是蕴含土壤环境变化的重要信息。由于黄土与古土壤成壤环境的气候差异,微生物群落结构特征可能会有不同的响应,但针对该问题的研究还十分有限。【方... 详细信息

【目的】黄土-古土壤序列是记录第四纪气候环境变化的良好载体,其内部的土壤微生物特征是蕴含土壤环境变化的重要信息。由于黄土与古土壤成壤环境的气候差异,微生物群落结构特征可能会有不同的响应,但针对该问题的研究还十分有限。【方法】选择任家坡(R)和九州台(J)两地黄土(RL和JL)-古土壤(RS和JS)序列,运用高通量测序技术和线性判别分析效应大小(linear discriminant analysis effect size,LEfSe)识别土壤原核生物群落结构和类群差异,基于原核生物分类单元功能注释(functional annotation of prokaryotic taxa,FAPROTAX)数据库进行群落功能预测,以及利用Mantel test探讨影响土壤原核生物群落稳定的环境因子。【结果】土壤中碳氮营养物质与气候变化的代用指标磁化率、Rb/Sr变化趋势一致,含量整体表现为古土壤(RS和JS)高,对应的黄土(RL和JL)低,这一特征在任家坡古土壤(RS)中尤为显著;在同一气候时期,九州台较任家坡更为干冷,并且九州台古土壤沉积阶段也受到较强冬季风的影响,使其气候冷干与暖湿转变呈渐变型。原核生物群落结构中酸杆菌门(Acidobacteria)、泉古菌门(Crenarchaeota)、绿弯菌门(Chloroflexi)等具有嗜热嗜温性质的细菌和古菌在任家坡黄土-古土壤(RL和RS)中丰度较高,芽单胞菌门(Gemmatimonadetes)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、广古菌门(Euryarchaeota)、异常球菌-栖热菌门(Deinococcus-Thermus)等耐旱、适宜极端环境中生存的细菌和古菌在九州台黄土-古土壤中(JL和JS)丰度较高。同时,生命产能、氮、锰、铁、氯元素循环相关功能基因在任家坡古土壤(RS)中表达量最高,而碳、氢、硫元素循环相关功能基因在任家坡黄土(RL)中表达量最高。与任家坡相比,九州台原核生物群落具有物种多样性高、功能种类少的特点。Mantel test分析进一步表明,有机碳(soil organic carbon,SOC)、含水率(soil water content,SWC)、总氮(total nitrogen,TN)和硝态氮(nitrate nitrogen,NO3−-N)是影响任家坡原核生物群落和功能稳定的关键环境因子,而TN、SOC、pH值和铵态氮(NH4+-N)是影响九州台原核生物群落和功能稳定的关键环境因子。【结论】在暖湿期,微生物群落分化出更多的功能种类,具有更旺盛的生命活动;在冷干期,微生物群落通过提高物种多样性来完成主要的生命活动功能,通过协同共生维持群落生存和稳定来适应环境胁迫。研究成果对认识气候变化对土壤微生物多样性和功能的影响具有重要意义。

关键词：黄土-古土壤序列原核生物群落结构功能古气候

Determination of the Henry’s Law Constant of Hexane in High-Viscosity Polymer Systems

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China Petroleum Processing & Petrochemical Technology 2023年第1期25卷 34-43页

作者： Qi Jibing Li Yuliang Liu Youzhi Yang Tong Liu yandong Yuan Zhiguo yi Jianjun Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China Petrochemical Research Institute Petro China Co Ltd.Beijing 102206China

The Henry’s law constant of volatiles in polymer systems is a crucial parameter reflecting the gas-liquid equilibrium,which is very important for devolatilization.In this research,polyolefin elastomer(POE)-cyclohexane and polydimethylsiloxane(PDMS)-hexane systems were studied,and the Henry’s law constant was obtained by measuring the gas phase equilibrium partial pressure when polymer solutions containing different mass fractions of volatiles reached a saturated state.The effects of temperature,type of volatiles,and polymer viscosity on the gas phase equilibrium partial pressure and Henry’s law constant of the volatiles were investigated.The results indicate that,with the increase of temperature and polymer viscosity,the gas phase equilibrium partial pressure and Henry’s law constant of volatiles increase.As temperature increases,the solubility of gas in liquid decreases.The relationship between the Henry’s law constant and temperature is consistent with the Arrhenius law.In the PDMS-hexane system,the gas phase equilibrium partial pressure and Henry’s law constant of n-hexane are higher than those of cyclohexane.The obtained Henry’s law constants can be used as a reference for perfecting the devolatilization process and improving the devolatilization effect.

关键词： Henry’s law constant gas-liquid equilibrium method hexane polyolefin elastomer(POE) polydimethylsiloxane(PDMS)

Multistage strain-hardening behavior of ultrastrong and ductile lightweight refractory complex-concentrated alloys

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Journal of Materials Science & Technology 2023年第18期149卷 73-87页

作者： Yuefei Jia Chang Ren Shiwei Wu Yongkun Mu Long Xu yandong Jia Wentao Yan Jun yi Gang Wang Institute of Materials Shanghai UniversityShanghai 200444China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100China Department of Mechanical Engineering National University of Singapore117575Singapore

Lightweight high-entropy alloys or complex-concentrated alloys have demonstrated great potential for engineering applications due to their high strength and lightweight.However,a weak strain-hardening ability and a limited tensile ductility remain their major hindrance.Here,a multistage strain-hardening effect is developed to ensure a high strength and still a sufficient ductility in a rolled and annealed(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(at.%)lightweight refractory complex-concentrated alloy(M1.5A-LRCCA).This multistage strain-hardening behavior is related to the microstructure and the corresponding initial aver-age dislocation density and distribution by comparison with rolled and annealed Ti_(44)V_(28)Zr_(14)Nb_(14)(M0-LRCCA)and as-cast(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(M1.5C-LRCCA).The microstructure,with homogeneously distributed submicron precipitations,a moderate initial average dislocation density,and uniform disloca-tion distribution(e.g.,M1.5A-LRCCA),is susceptible to producing various deformation substructures,such as dislocation substructures(slip bands,Taylor lattices,microbands,DDWs),shear bands,and deformation twins,which results in the multistage strain-hardening behavior.This method of achieving multistage strain hardening behavior through a microstructure modulation is significant for engineering applications of lightweight high-entropy alloys or complex-concentrated alloys,and it might be extended to other lightweight and high-strength alloys.

关键词： High-entropy alloy/complex-contracted alloy Lightweight Strain hardening BCC Mechanical properties

Processing Technique of Carbonizing by Stir-Frying for Baked Rheum tanguticum Maxim.ex Balf. Optimized by Orthogonal Design

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Medicinal Plant 2019年第5期10卷 50-52页

作者： Shihe LIN yandong yi Chuanqi HUANG Quanwei YANG Nancai YU Department of Pharmacy Wuhan Hospital of Traditional Chinese and Western Medicine

[Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(5-HMF)was determined by HPLC.The main influencing factors of baking effect were baking temperature,baking time and tablet specifications.The L 9(34)orthogonal design experiment was carried out to optimize the processing technique of R.tanguticum carbon.[Results]The optimum processing technique was as follows:small-sized tablets,controlled oven baking temperature at(210±2)℃,and baking time of 20 min.[Conclusions]The optimum processing technique of R.tanguticum carbon is reasonable and feasible.Thus,this experiment can provide a certain reference for processing method and quality control of R.tanguticum carbon.

关键词： Rheum tanguticum carbon Carbonizing by Stir-Frying Baking method Processing technique

Diffusion Characteristics and Removal of Cyclohexane in Polyolefin Elastomer Melt

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China Petroleum Processing & Petrochemical Technology 2022年第4期24卷 76-85页

作者： Qi Jibing Yang Tong Liu yandong Yuan Zhiguo Zhang Qiaoling Liu Youzhi yi Jianjun Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China Petrochemical Research Institute PetroChina Co.Ltd.Beijing 102206China

The diffusion coefficient of volatiles in polymer solutions is a crucial parameter to describe the mass transfer efficiency and ability of volatiles.In this research,polyolefin elastomer(POE)was used as a polymer,and cyclohexane was used as a volatile.A gravimetric analysis was applied to measure the diffusion coefficient of cyclohexane in POE.The devolatilization rate of the POE-cyclohexane system under different conditions was measured.The effects of temperature,film sample thickness,and initial concentration of volatiles on the devolatilization rate were discussed.Based on the devolatilization rate data,the average diffusion coefficient of cyclohexane in POE was obtained by fitting with a mathematical model.The experimental results indicate that the devolatilization rate increased with increasing temperature and initial concentration of volatiles,but it decreased with increasing sample thickness.As the thickness increased,the overall diffusion resistance increased.As the temperature increased,the molecular movement increased,resulting in the increase of average diffusion coefficient.The relationship between the diffusion coefficient of the POE-cyclohexane system and temperature follows the Arrhenius law.The diffusion activation energy E=6201.73 J/mol,and the pre-exponential factor of the diffusion coefficient D0=2.64×10^(-10) m^(2)/s.This work can provide basic data for exploring the devolatilization of POE polymers and serves as a useful reference for enhancing the effect of devolatilization.

关键词： diffusion coefficient gravimetric analysis polyolefin elastomer(POE) cyclohexane devolatilization rate

Phase Evolution and Thermal Expansion Behavior of aγ′Precipitated Ni-Based Superalloy by Synchrotron X-Ray Diffraction

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Acta Metallurgica Sinica(English Letters) 2022年第1期35卷 93-102页

作者： Zhiran Yan Qing Tan Hua Huang Hailong Qin yi Rong Zhongnan Bi Runguang Li Yang Ren yandong Wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing100083China Department of Microstructure Physics and Alloy Design Max-Planck-Institut Für Eisenforschung GmbH40237DüsseldorfGermany Department of Materials Imperial College LondonKensingtonLondonSW72AZUK Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research InstituteBeijing100081China Department of Mechanical Engineering Technical University of Denmark2800Kongens LyngbyDenmark X-Ray Science Division Advanced Photon SourceArgonne National LaboratoryArgonneIL60439USA

The phase evolution and thermal expansion behavior in superalloy during heating play an essential role in controlling the size and distribution of precipitates,as well as optimizing thermomechanical properties.Synchrotron X-ray diffraction is able to go through the interior of sample and can be carried out with in situ environment,and thus,it can obtain more statistics information in real time comparing with traditional methods,such as electron and optical microscopies.In this study,in situ heating synchrotron X-ray diffraction was carried out to study the phase evolution in a typicalγ′phase precipitation strengthened Ni-based superalloy,Waspaloy,from 29 to 1050°C.Theγ′,γ,M_(23)C_(6)and M C phases,including their lattice parameters,misfits,dissolution behavior and thermal expansion coefficients,were mainly investigated.Theγ′phase and M_(23)C_(6)carbides appeared obvious dissolution during heating and re-precipitated when the temperature dropped to room temperature.Combining with the microscopy results,we can indicate that the dissolution of M_(23)C_(6)leads to the growth of grain andγ′phase cannot be completely dissolved for the short holding time above the solution temperature.Besides,the coefficients of thermal expansions of all the phases are calculated and fitted as polynomials.

关键词： Superalloy Waspaloy Lattice misfit Coefficients of thermal expansion X-ray diffraction Synchrotron radiation

Formation mechanism of co-axial grain boundaries in a Mg alloy

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Journal of Magnesium and Alloys 2023年第3期11卷 1094-1101页

作者： Zhen Peng yi Liu Lirong Xiao Yue Yang Bo Gao Mengning Xu Zhaohua Hu yandong Yu Xuefei Chen Hao Zhou School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Association for Science and Technology Nanjing University of Science and TechnologyNanjing 210094China Ansteel Beijing Research Institute Co. Ltd.Beijing 102209China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China

Due to the insufficient slip systems in hexagonal close-packed structure,twinning is frequently activated to support stable plastic deformation of Mg alloy.In this work,we found four typical twin-like interfaces with misorientations of 102°,109°,142°and 149°,respectively,which had not only a shared[1120]zone axis of neighboring grains,but also overlapped diffraction spots similar to twins.However,highresolution transmission electron microscope(HRTEM)analysis revealed that the interfaces in real space deviated from the supposed twinning planes in reciprocal space,i.***.their overlapped diffraction spots.We clarified that the incoherent interfaces were co-axial grain boundaries(CGBs).Additionally,a special angle ofθ,close to 90°,between the interface and one side of basal plane,was frequently formed in CGBs.We proposed that interaction of multiple twinning contributes to the formation of CGBs,and theθis formed due to alternative tensile and compression twinning under a uniaxial loading.

关键词： Interface Twinning Tilt boundaries TEM Formation mechanism