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Shoot Apex Demand Determines Assimilate and Nutrients Partitioning and Nutrient-uptake Rate in Tobacco Plants

Journal of Integrative Plant Biology 2007年第11期49卷 1654-1661页

作者： huai-yu Yang Chun-Jian Li Fu-Suo Zhang The Key Laboratory of Plant Nutrition Ministry of Agriculture Key Laboratory of Plant-Soil Interactions Ministry of Education Department of Plant Nutrition China Agricultural University Beijing 100094 China

Our previous experiment revealed that apex-removed plants have larger root systems but a lower K＋-uptake rates than intact tobacco plants. Since the apex is not only a center of growth and metabolism, but also an important place of auxin synthesis and export, the aims of this study were to distinguish whether the apex demand or auxin synthesized in the apex regulates assimilate and nutrients partitioning within plant, and to explain the reason for the lower K＋-uptake rate of the apex-removed plant. In comparison with the control plant, covering the shoot apex with a black transparent plastic bag reduced net increases in dry matter and nutrients; however, the distribution of the dry matter and nutrients between shoot and roots and nutrient-uptake rates were not changed. Removal of the shoot apex shifted the dry mass and nutrients distributions to roots, and reduced the rate of nutrient uptake. Application of 1-naphthylacetic acid （NAA） could partly replace the role of the removed apex, stimulated assimilate and nutrient deposition into the treated tissue, and enhanced the reduced plasma membrane ATPase activity of roots to the control level. However, treatment of the apex-removed plants with NAA could not rescue the reduced nutrient uptake rate and the shifted assimilates and nutrients partitioning caused by excision of the apex. Higher nutrient uptake rate of the intact plants could not be explained by root growth parameters, such as total root surface area and number of root tips. The results from the present study indicate that strong apex demand determined assimilates and nutrients partitioning and nutrient-uptake rate in tobacco （Nicotiana tabacum） plants.

关键词： assimilate and nutrient partitioning auxin nutrient uptake removal of the shoot apex shoot apex demand tobacco (Nicotiana tabacum).

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Dielectric,magnetic and microwave absorbing properties of polyaniline-Co0.7Cr0.1Zn0.2Fe2O4 composites

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Rare Metals 2017年第2期36卷 118-122页

作者： Rui-Ting Ma huai-yu Shang Xiao Wang Dan Jiang School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159China

The spinel cobalt chromium zinc ferrites（Co0.7Cr0.1Zn0.2Fe2O4） and the polyaniline（PANI）-Co0.7Cr0.1Zn0.2Fe2O4 composites were prepared by polyacrylamide gel and an in situ polymerization method,*** structure of the synthesized material was characterized by X-ray diffraction（XRD） and Fourier transform infrared spectrometer（FTIR）,which shows that the spinel Co0.7Cr0.1Zn0.2Fe2O4 ferrites and the PANI Co0.7Cr0.1Zn0.2Fe2O4 composites are *** a small amount of Co^2＋ in the octahedron ferrite is replaced by Cr^3＋,the lattice constant of Co0.8Cr0.2Zn0.2Fe2O4 ferrites reduces from0.8409 to 0.8377 *** magnetic properties of the two materials were investigated by vibrating sample magnetometer（VSM）.The VSM results confirm that the saturation magnetization（Ms）,remanent magnetization（Mr） and coercive force（Hc） of the PANI-Co0.7Cr0.1Zn0.2Fe2O4composites are 8.80 mA·m^2·g^-1,3.14 mA·m^2·g^-1 and37.22 kA·m^-1,respectively,which are smaller than those of the Co0.7Cr0.1Zn0.2Fe2O4 *** microwave absorbing capability of the two materials was studied by waveguide *** the frequency range of 5-20 GHz,two reflection loss maximum values of the PANI-Co0.7Cr0.1Zn0.2Fe2O4 composites appear at 14.1 and 17.9 GHz with-13.17 and-15.36 dB,respectively,which are obviously higher than those of the Co0.7Cr0.1Zn0.2Fe2O4 ferrites.

关键词： Composites Microwave absorbing properties Dielectric properties Magnetic properties

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Some Open Problems on Simultaneous Stabilization of Linear Systems

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Journal of Systems Science & Complexity 2016年第2期29卷 289-299页

作者： LI Wang WANG long yu Wensheng Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai 200062China. Intelligent Control Laboratory College of EngineeringPeking UniversityBeijing 100871China. College of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China.

Simultaneous stabilization of linear systems is a fundamental issue in the system and control theory, and is of theoretical and practical significance. In this paper, the authors review the recent research progress and the state-of-art results on simultaneous stabilization of single-input single-output linear time-invariant systems. Especially, the authors list the ever best results on the parameters involved in the well known ＂French Champagne Problem＂ and ＂Belgian Chocolate Problem＂ from the point of view of mathematical theoretical analysis and numerical calculation. And the authors observed that Boston claimed the lower bound of 5 can be enlarged to 0.976461 in 2012 is not accurate. The authors hope it will inspire further study on simultaneous stabilization of several linear systems.

关键词： Belgian Chocolate problem French Champagne Problem linear systems simultaneous stabilization.

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Dynamic fracture toughness of high strength metals under impact loading:increase or decrease

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Acta Mechanica Sinica 2011年第4期27卷 559-566页

作者： Ze-Jian Xu yu-long Li State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology 100081 Beijing China School of Aeronautics Northwestern Polytechnical University 710072 Xi'an China

An elusive phenomenon is observed in previous investigations on dynamic fracture that the dynamic fracture toughness （DFT） of high strength metals always increases with the loading rate on the order of TPa.m1/2.s-1. For the purpose of verification, variation of DFT with the loading rate for two high strength steels commonly used in the aviation industry, 30CrMnSiA and 40Cr, is studied in this work. Results of the experiments are compared, which were conducted on the modified split Hopkinson pressure bar （SHPB） apparatus, with striker velocities ranging from 9.2 to 24.1 m/s and a constant value of 16.3 m/s for 30CrMnSiA and 40Cr, respectively. It is observed that for 30CrMnSiA, the crack tip loading rate increases with the increase of the striker velocity, while the fracture initiation time and the DFT simultaneously decrease. However, in the tests of 40Cr, there is also an increasing tendency of DFT, similar to other reports. Through an in-depth investigation on the relationship between the dynamic stress intensity factor （DSIF） and the loading rate, it is concluded that the generally increasing tendency in previous studies could be false, which is induced from a limited striker velocity domain and the errors existing in the experimental and numerical processes. To disclose the real dependency of DFT on the loading rate, experimentsneed to be performed in a comparatively large striker velocity range.

关键词： Dynamic fracture. Fracture toughness Loadingrate effect - Hopkinson pressure bar High strength metal

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基于化学衍生化的质谱技术在脂质分析中的研究进展

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分析测试学报 2025年第1期44卷 73-81页

作者：黄龙会石幸玉谢海洲周婷华南理工大学生物科学与工程学院广东广州510006

脂质不仅是细胞膜的主要组成部分,还参与多种生命活动如能量存储、信号传导等,在生命体中发挥着重要作用。质谱以其高灵敏度、准确度和快速分析能力,在结构表征中表现出色,已成为脂质分析的核心技术。然而,由于脂质的结构多样性和高度... 详细信息

脂质不仅是细胞膜的主要组成部分,还参与多种生命活动如能量存储、信号传导等,在生命体中发挥着重要作用。质谱以其高灵敏度、准确度和快速分析能力,在结构表征中表现出色,已成为脂质分析的核心技术。然而,由于脂质的结构多样性和高度相似性,其质谱定性、定量分析仍然面临着诸多挑战。化学衍生化技术通过对脂质进行结构修饰,可以改善脂质的离子化效率,并提高质谱检测的灵敏度与选择性,有效促进脂质的结构鉴定和定量分析。近年来,化学衍生化与质谱技术的结合策略广泛应用于脂质分析。该文综述了近十年来基于化学衍生化的质谱技术在解析脂质精确结构、提高检测灵敏度和定量准确性,以及结合新型质谱应用中的研究进展。

关键词：脂质化学衍生化质谱结构表征

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Some notes on numerical simulation of the turbulent cavitating flow with a dynamic cubic nonlinear sub-grid scale model in OpenFOAM

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Journal of Hydrodynamics 2020年第4期32卷 790-794页

作者： Zi-yang Wang Xian-bei Huang huai-yu Cheng Bin Ji State Key Laboratory of Water Resources and Hydropower Engineering Science School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China College of Electrical Energy and Power EngineeringYangzhou UniversityYangzhou 225127China

The accuracy of large eddy simulation(LES)is highly dependent on the performance of sub-grid scale(SGS)*** the present paper,a dynamic cubic nonlinear sub-grid scale model(DCNM)proposed by Huang et *** implemented for the simulation of unsteady cavitating flow around a 3-D Clark-Y hydrofoil in *** performance in predicting the evolution of cloud cavitation is discussed in *** simulation with a linear model,the dynamic Smagorinsky model(DSM),is also conducted as a *** results with DCNM show a better agreement with the available experimental *** comparison between DCNM and DSM further suggests that the DCNM is able to predict the backscatter more precisely,which is an important feature in *** characteristics of DCNM is analyzed to account for its advantages in the prediction of unsteady cloud cavitation as *** results reveal that it is the nonlinear terms of DCNM that makes DCNM capture sub-grid scale vortices better and more suitable for studying the transient behaviors of cloud cavitation than DSM.

关键词： Cavitation large eddy simulation(LES) nonlinear sub-grid scale model OpenFOAM

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Effects of Crystallization Temperature and Blend Ratio on the Crystal Structure of Poly(butylene adipate) in the Poly(butylene adipate)/Poly(butylene succinate) Blends

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Chinese Journal of Polymer Science 2014年第4期32卷 488-496页

作者： Hai-jun Wang Hui-ping Feng 王学川 Pei-ying Guo Ting-shan Zhao long-fang Ren Xi-huai Qiang yu-hao Xiang 晏超 Key Laboratory of Chemistry and Technology for Light Chemical Industry Ministry of EducationShaanxi University of Science and Technology School of Material Science & Engineering Jiangsu University of Science and Technology

The effects of crystallization temperature and blend ratio on the polymorphic crystal structures of poly（butylene adipate）（PBA） in poly（butylene succinate）（PBS）/poly（butylene adipate）（PBS/PBA） blends were studied by means of differential scanning calorimetry （DSC）, wide-angle X-ray diffraction （XRD） and atomic force microscopy （AFM）. It was revealed that the polymorphism of PBA can be regulated by the blend ratio even in a non-isothermal crystallization process. The results demonstrate that high temperature favors fiat-on α crystals, while low temperature contributes to edge-on β crystals. It was also found that the effect of blend ratio on the crystallization mechanism of PBA is well coincident with that of the crystallization temperature. The increment of PBS content in the PBS/PBA blend gives rise to more β-form crystals of PBA. For those PBS/PBA blends with low PBA content, the interlamellar phase segregation of PBA makes its molecular chains so difficult to diffuse from one isolated microdomain to another that high crystallization temperature and sufficiently long crystallization time will be required if the PBA α-type crystals are targeted.

关键词： Blends Crystallization Poly(butylene adipate) Poly(butylene succinate).

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Temporal and spatial characteristics of monopole acoustic energy dominated by unsteady thermodynamic cavitating flow

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Journal of Hydrodynamics 2021年第4期33卷 867-871页

作者： Xin-cheng Wang Xiao-rui Bai huai-yu Cheng Bin Ji State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

The acoustic propagation characteristics of the cavitating flow are essential for the noise suppression, but were not well studied. In the current paper, a new technique concerning the propagation path of the monopole acoustic energy is presented and two typical thermodynamic cavitation modes (the inertial and thermal modes) are selected to investigate the effect of the cavity shedding dynamics on the acoustic propagation path. In the inertial mode, the temporal variation and the spatial distributions of the monopole acoustic energy as well as the divergence of the monopole acoustic pressure are both more powerful and concentrated than that in the thermal mode. The acoustic propagation path in the thermal mode strictly satisfies the feature of the convective amplification, while there exists another propagation direction close to the normal direction of the foil surface in the inertial mode. Furthermore, the occurrence of the normal direction propagation will make the path deviate from the convective direction.

关键词： Thermodynamic cavitation acoustic propagation path hydroacoustic inertial mode thermal mode

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Gut microbiota in cancer initiation,development and therapy

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Science China Life Sciences 2025年

作者： Ruyi Zhang Xiang Zhang Harry Cheuk Hay Lau Jun yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong Kong

Cancer has long been associated with genetic and environmental factors,but recent studies reveal the important role of gut microbiota in its initiation and *** 13%of cancers are linked to infectious agents,highlighting the need to identify the specific microorganisms *** microbiota can either promote or inhibit cancer growth by influencing oncogenic signaling pathways and altering immune *** can lead to cancer,while certain probiotics and their metabolites may help reestablish microecological balance and improve anti-tumor immune *** into targeted approaches that enhance therapy with probiotics is ***,the effects of probiotics in humans are complex and not yet fully ***,methods to counteract harmful bacteria are still in *** clinical trials also indicate that modifying gut microbiota may help manage side effects of cancer *** research is crucial to understand better how gut microbiota can be used to improve cancer prevention and treatment outcomes.

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Experimental Study on the Viscosity of Soft Cohesive Sediments Around A Vibrating Pillar

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China Ocean Engineering 2022年第2期36卷 289-298页

作者： DONG Chuan-ming yu Guo-liang ZHANG huai-xin ZHANG Min-xi SKLOE CISSESchool of Naval ArchitectureOcean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Navigation College Dalian Maritime UniversityDalian 116026China

Offshore structures are subject to environmental loads such as waves,currents,or wind,which may induce cyclic lateral vibration at the *** cyclic vibration loadings may affect the rheological property of the sediments adjacent to the foundation and the stability of the *** is especially true when the structures are founded on cohesive sedimentary *** this study,the viscosity of soft cohesive sediments adjacent to a vibrating pillar was considered,and as a primary index of the rheological characteristics of the *** investigation was performed using the sinking ball *** experimental findings indicated that the viscosity of cohesive sediments decrease with increase of the liquidity index and vibration intensity.A simple semi-empirical formula was *** structures of the cohesive sediments were destroyed due to the mechanical vibration,and the sediments were fluidized during vibration *** shear strength of the cohesive sediments decreased with increased vibration intensity,not only because of the increased pore water pressure but also the decreased viscosity of cohesive sediments following sediment fluidization.

关键词： cohesive sediment vibration intensity viscosity coefficient fluidization liquidity index

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