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Transport of cadmium from soil to grain in cereal crops: A review

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Pedosphere 2021年第1期31卷 3-10页

作者： Jian feng MA Ren Fang ShEN Ji feng ShAO Institute o f Plant Science and Resources Okayama UniversityChuo 2-20-1Kurashiki 710-0046Japan State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityLin'An 311300China

Due to rapid urbanization and industrialization, many soils for crop production are contaminated by cadmium(Cd), a heavy metal highly toxic to many organisms. Cereal crops such as rice, wheat, maize, and barley are the primary dietary source of Cd for humans, and reducing Cd transfer from soil to their grains is therefore an important issue for food safety. During the last decade, great progress has been made in elucidating the molecular mechanisms of Cd transport, particularly in rice. Inter-and intraspecific variations in Cd accumulation have been observed in cereal crops. Transporters for Cd have been identified in rice and other cereal crops using genotypic differences in Cd accumulation and mutant approaches. These transporters belong to different transporter families and are involved in the uptake, vacuolar sequestration, root-to-shoot translocation, and distribution of Cd. Attempts have been made to reduce Cd accumulation in grains by manipulating these transporters through overexpression or knockout of the transporter genes, as well as through marker-assisted selection breeding based on genotypic differences in Cd accumulation in the grains. In this review, we describe recent progress on molecular mechanisms of Cd accumulation in cereal crops and compare different molecular strategies for minimizing Cd accumulation in grains.

关键词： barley gene knockout gene overexpression genotypic difference maize rice transporter wheat

Convergence analysis of the corrected Uzawa algorithm for symmetric saddle point problems

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Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 29-35页

作者： LU Jun-feng hangzhou Institute of Commerce Zhejiang Gongshang University

For the large sparse saddle point problems, Pan and Li recently proposed in [h. K. Pan, W. Li, Math. Numer. Sinica, 2009, 31（3）： 231-242] a corrected Uzawa algorithm based on a nonlinear Uzawa algorithm with two nonlinear approximate inverses, and gave the detailed convergence analysis. In this paper, we focus on the convergence analysis of this corrected Uzawa algorithm, some inaccuracies in [h. K. Pan, W. Li, Math. Numer. Sinica, 2009, 31（3）： 231-242] are pointed out, and a corrected convergence theorem is presented. A special case of this modified Uzawa algorithm is also discussed.

关键词： Saddle point problem Uzawa algorithm convergence analysis

语言模型辅助的英语科技论文摘要语步语料库构建研究

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外语学刊 2025年第1期 29-38页

作者：李洪政王若锦刘芳冯冲北京理工大学外国语学院北京102488 语言工程与认知计算工信部重点实验室北京102488 北京理工大学计算机学院北京100081

语步结构是学术论文中的文本语篇单位,在学术用途英语等方面具有重要价值。尽管关于学术论文的语步研究非常丰富,但语步标注数据资源仍然相对较少。本研究借助自然语言处理领域的语言模型构建了涵盖多个学科领域的英语科技论文摘要语步... 详细信息

语步结构是学术论文中的文本语篇单位,在学术用途英语等方面具有重要价值。尽管关于学术论文的语步研究非常丰富,但语步标注数据资源仍然相对较少。本研究借助自然语言处理领域的语言模型构建了涵盖多个学科领域的英语科技论文摘要语步标注语料库,包括近3.4万个语步结构。语料库构建的第一阶段依靠专家标注形成高质量语料,在第二阶段也是主要阶段,采用基于BERT架构的自动标注模型,在保证标注质量的同时能够快速提升标注速度、扩大标注规模。本研究随后开展了摘要语步自动标注识别实验,对比自动标注模型与大语言模型ChatGPT和Claude3识别不同学科领域的语步结构的效果,验证了模型和语料库的价值。该研究能为科技论文写作智能批改等自然语言处理任务以及学术用途英语等外语教学与研究等提供必要的数据资源,也验证了大语言模型辅助构建语言资源的可能性,体现了语言智能驱动的智慧外语教育的重要性,能有效推动外语教育数字化转型。

关键词：语步结构语料库摘要文本大语言模型

Enforced Freedom: Electric-Field-Induced Declustering of Ionic-Liquid Ions in the Electrical Double Layer

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Energy & Environmental Materials 2020年第3期3卷 414-420页

作者： Yufan Zhang Ting Ye Ming Chen Zachary A.h.Goodwin Guang feng Jun huang Alexei A.Kornyshev IEK-13 Institute of Energy and Climate ResearchForschungszentrum Jülich GmbHJülich 52425Germany State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074China Department of Chemistry Imperial College LondonMolecular Sciences Research HubWhite City CampusLondon W120BZUK Department of Physics Imperial College LondonSouth Kensington CampusLondon SW72AZUK Thomas Young Centre for Theory and Simulation of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK hunan Provincial Key Laboratory of Chemical Power Sources College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China

Ions in the bulk of solvent-free ionic liquids bind into ion pairs and *** competition between the propensity of ions to stay in a bound state,and the reduction of the energy when unbinding in electric field,determines the portion of free ions in the electrical double *** present the simplest possible mean-field theory to study this effect."Cracking"of ion pairs into free ions in electric field is accompanied by the change of the dielectric response of the ionic *** predictions from the theory are verified and further explored by molecular dynamics simulations.A particular finding of the theory is that the differential capacitance vs potential curve displays a bell shape,despite the low concentration of free charge carriers,because the dielectric response reduces the threshold concentration for the bell-to camelshape *** presented theory does not take into account overscreening and oscillating charge distributions in the electrical double *** in spite of the simplicity of the model,its findings demonstrate a clear physical effect:a preference to be a charged monopole rather than a dipole(or higher order multipole)in strong electric field.

关键词： differential capacitance ion pairs ionic liquids unbinding

Ephemeral gully recognition and accuracy evaluation using deep learning in the hilly and gully region of the Loess Plateau in China

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International Soil and Water Conservation Research 2022年第3期10卷 371-381页

作者： Boyang Liu Biao Zhang hao feng Shufang Wu Jiangtao Yang Yufeng Zou Kadambot h.M.Siddique Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling712100China Institute of Water Saving Agriculture in Arid Areas of China Northwest A&F UniversityYangling712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling712100China Department of Foreign Languages Northwest A&F UniversityYangling712100China The UWA Institute of Agriculture and School of Agriculture&Environment The University of Western AustraliaPerthWA6001Australia

Ephemeral gullies are widely distributed in the hilly and gully region of the Loess Plateau and play a unique role in the slope gully erosion *** and accurate identification of ephemeral gullies impacts the distribution law and development trend of soil erosion on the Loess *** learning algorithms can quickly and accurately process large data samples that recognize ephemeral gullies from remote sensing ***,we investigated ephemeral gullies in the Zhoutungou watershed in the hilly and gully region of the Loess Plateau in China using satellite and unmanned aerial vehicle images and combined a deep learning image semantic segmentation model to realize automatic recognition and feature *** Accuracy,Precision,Recall,F1value,and AUC,we compared the ephemeral gully recognition results and accuracy evaluation of U-Net,R2U-Net,and SegNet image semantic segmentation *** SegNet model was ranked first,followed by the R2U-Net and U-Net models,for ephemeral gully recognition in the hilly and gully region of the Loess *** ephemeral gully length and width between predicted and measured values had RMSE values of 6.78 m and 0.50 m,respectively,indicating that the model has an excellent recognition *** study identified a fast and accurate method for ephemeral gully recognition in the hilly and gully region of the Loess Plateau based on remote sensing images to provide an academic reference and practical guidance for soil erosion monitoring and slope and gully management in the Loess Plateau region.

关键词： Deep learning Remote sensing image Ephemeral gully recognition Loess plateau Image semantic segmentation Accuracy evaluation

On the formation of shear bands in a metallic glass under tailored complex stress fields

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Journal of Materials Science & Technology 2020年第18期52卷 112-117页

作者： S.h.Chen T.Li W.J.Chang h.D.Yang J.C.Zhang h.h.Tang S.D.feng F.F.Wu Y.C Wu School of Mechanical Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China School of Materials Science and Engineering Liaoning University of TechnologyJinzhou 121001China School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China

The formation of shear bands in metallic glasses(MGs)was examined by tailoring localized complex stress fields(LCSFs).The findings have shown that the LCSFs in MGs can increase the localization of strained atoms and accelerate the release of accumulated deformation energy for initiating a shear band in confined and thin-layered *** findings not only add more knowledge to the formation mechanisms of shear bands in MGs,but also provide possible rationale for the discrepancies in the mechanical properties of different-sized *** compared with the bulk samples,the higher strength and larger elastic limits in nanoscaled MGs could be attributed to the elimination of stress-concentrators,which can serve as LCSFs.

关键词： Localized complex stress field Shear band Metallic glass Molecular dynamics simulation Size effect

INFLUENCE OF INTERNAL hYDROGEN ON ThE hYDROGENEMBRITTLEMENT OF AUSTENITIC STAINLESS STEEL

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Acta Metallurgica Sinica(English Letters) 1997年第3期10卷 228-232页

作者： Y Tan D.h Zhouand J. feng (Institute of Structural Mechanics, Chengdu 610003, China) Inst of Structural Mechanics Chengdu China

The hE (hydrogen embrittlement) behavior of two kinds of austenitic stee Cr21Ni6Mn9 and 1Cr18Ni9Ti is reprted in this paper. The factors (temperc-ture/strain rate/stress concentration coefficient and purity of hydrogen) are restricted to the severe conditions under which hE is easy to occur. The concentmtion of in-ternal hydrogen in samples is changed by varying the time during which samples are placed in 24 MPa hydrogen at 473 K Then the tensile properties of the samples are tested. The results indicate that the degree of the hydrogen-induced plastic loss (L)of Cr21Ni6Mn9 is different with the internal hydrogen(Ch). howeven even when Ch is as high as 70 PPm L is 15% and the fracture may be explained as a larpe amount of internal hydrogen hinders the cross-slip of dislocations when the steel is *** the metastable steel 1Cr18Ni9Ti the hydrogen-induced plastic loss is severer than that of Cr21Ni6Mn9. When Ch is 40 PPm its L is as high as 42%. The mechanism may be explained as a larpe amount of hyderpen decreases the stacking fault enerpy and brittle ε-phase is produed in the high Ch areas.

关键词： austenitic stainless steel internal hydrogen hydrogen embrittlement hydrogen-induced ductility loss

Vanadium-Doped Semi-Insulating 6h-SiC for Microwave Power Device Applications

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Journal of Materials Science & Technology 2009年第1期25卷 102-104页

作者： Liana Ning Zhihong feng Yingmin Wang Kai Zhang Zhen feng State Key Laboratory of Crystal Materials Shandong University Jinan 250100 hebei Semiconductor Research Institute Shijiazhuang 050051 China

Two-inch semi-insulating SiC bulk crystals with resistivity higher than 1 × 10^6 Qcm were achieved by vanadium doping during sublimation. Secondary-ion-mass-spectrometry （SIMS） was employed to determine the concentration of impurities in the crystals, such as B, AI, V and N. These results indicated that the concentration of nitrogen and aluminum kept on decreasing and the concentration of B and V was almost constant during the whole growth. An inner crucible was used to control the exhausting of vanadium, which made the uniformity of the high resistivity （〉1×10^6 Ωcm） in the wafer up to 80%. high-performance AlGaN/GaN high-electronmobility-transistor （hEMT） materials and devices were grown and fabricated on semi-insulating 6h-SiC sub- strates. The two-dimensional electron gas （2DEG） mobility at room-temperature was 1795 cm^2/V-s. The charge carrier concentration of the substrate determined by capacitance-voltage （C-V） test was 7.3×10^15 cm^-3. The device with a gate width of I mm exhibits a maximum output power of 5.5 W at 8 Ghz, which proves the semi-insulating property of the substrates indirectly.

关键词： Silicon Carbide Semi-insulating Vanadium-doped AlGaN/GaN hEMT

STUDIES OF LOW-CONCENTRATION ChROMATE PASSIVE FILM FOR ZINC-BASED ALLOY COATED STEEL WIRES

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 736-738页

作者： Li, Y. Wang, h.R. feng, F.L. Wei, X.J. Northeastern Univ Shenyang China

The corrosion resistance of a low concentration chromate passive film for zinc based alloy coated steel wires was assessed by salt spray and electrochemical corrosion tests. XPS and AES analyses showed that the comp... 详细信息

关键词： chromate passive film zinc based alloy coating XPS AES