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Species divergence in seedling leaf traits and tree growth response to nitrogen and phosphorus additions in an evergreen broadleaved forest of subtropical China

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Journal of Forestry Research 2023年第1期34卷 137-150页

作者： Xuemin Ye Wensheng Bu Xiaofei Hu Bin liu kuan Liang Fusheng Chen Key Laboratory of National Forestry and Grassland Administration On Forest Ecosystem Protection and Restoration of Poyang Lake Watershed Jiangxi Agricultural UniversityNanchang 330045People’s Republic of China Jiangxi Provincial Key Laboratory of Silviculture College of ForestryJiangxi Agricultural UniversityNanchang 330045People’s Republic of China School of Management Nanchang UniversityNanchang 330045People’s Republic of China

Tree competitiveness generally depends on trait plasticity in response to environmental *** effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’s subtropical *** study examined the seedling leaf traits and net primary productivity of all trees>5 cm DBH of two dominant species,Schima superba and Castanopsis carlesii,in an evergreen broadleaved forest fertilized with nitrogen(+N),phosphorus(+P),and nitrogen plus phosphorus(N+P).The effect of N on seedling leaf traits was stronger than P,while fertilization in general was species *** mass per unit area decreased with N for *** seedlings but not for *** N,P,and N/P ratios changed with N addition for both *** four N fractions of carboxylation,bioenergetics,cell wall,and other N metabolites in *** leaves responded significantly to fertilization,while only the cell wall in *** a leaves *** leaf functional traits,including light-saturated photosynthetic rates,water,N,and P use efficiencies,chlorophyll and non structural carbohydrate contents increased with N addition in *** a and by P addition in *** closure at the stand-level increased due to *** biomass and relative growth rate of *** a was not affected by any treatments,while both for *** significantly decreased with N+P ***,nutrient limitation may vary at a small scale among species in a subtropical forest based on their responses of seedling traits and net primary productivity to *** traits are not correlated with the net primary productivity of larger trees except for N fractions,because low light conditions induced by fertilization reduces the proportion of N allocated to photosynthesis in *** addition,acclimation differences of tree species may increase the uncertainty of community succession.

关键词： Ecophysiology Fertilization acclimation N fractions Nutrient limitation Photosynthesis Relative growth rate

Effect of PVA Fiber on the Dynamic and Static Mechanical Properties of Concrete under Freeze-thaw Cycles at Extremely Low Temperature(-70℃)

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Journal of Wuhan University of Technology(Materials Science) 2023年第2期38卷 366-373页

作者： liu Jun JIANG ting YANG Yuanquan ZHOU Yifei College of Materials Science and Engineering Shenyang Ligong UniversityShenyang110158China

In order to study the effect of PVA fiber on the dynamic and static mechanical properties of low-temperature freeze-thaw concrete under the saturated surface dry state,different contents of PVA fiber were added to prepare concrete in this *** concrete was subjected to compression,flexural and SHPB impact tests combined with scanning electron microscopy for microstructure analysis,after different times of freeze-thaw cycles in the temperature range of 20-70℃.The experimental results show that the compressive strength of the PVA fiber reinforced concrete first increases and then decreases after freeze and thaw cycles,and the compressive strength is positively correlated with the fiber *** flexural strength gradually decreases with freeze-thaw *** flexural strength of the concrete with 1.2 kg/m^(3) of PVA fiber presents the lowest strength loss after 45 freeze and thaw cycles,which is about 14%.The dynamic failure strength gradually decreases with the increase of freeze-thaw times,and the reduction amplitude decreases with the increase of PVA fiber *** best impact resistance is achieved when the PVA fiber dosage is 1.2 kg/m^(3).

关键词： PVA fiber freeze-thaw cycle SHPB impact test microstructure mechanical properties

Some results on zeros and uniqueness of difference-differential polynomials

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Applied Mathematics(A Journal of Chinese Universities) 2012年第1期27卷 94-104页

作者： liu Kai liu Xin-ling CAO ting-bin Department of Mathematics Nanchang UniversityNanchang 330031China

We consider the zeros distributions of difference-differential polynomials which are the derivatives of difference products of entire functions. We also investigate the uniqueness problems of difference-differential p... 详细信息

关键词： zero sharing value uniqueness difference-differential polynomial.

Stability characteristics and airworthiness requirements of blended wing body aircraft with podded engines

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Chinese Journal of Aeronautics 2022年第6期35卷 77-86页

作者： Lixin WANG Ning ZHANG Hailiang liu ting YUE School of Aeronautics Science and Engineering Beihang UniversityBeijing 100083China

Blended-Wing-Body(BWB)aircraft have a relatively short fuselage and no horizontal tail,and they usually adopt podded engines and a V tail instead of a vertical ***,BWB aircraft have decreased longitudinal and directional static stability and *** this paper,the three-axis static and dynamic stability characteristics of an example BWB aircraft with podded engines are *** to the differences in flight characteristics of BWB aircraft and conventional aircraft,the different airworthiness requirements for BWB aircraft are analyzed:first,based on current airworthiness regulations and transport aircraft flying quality specification,the relaxation requirement of longitudinal static stability for BWB aircraft is studied;second,the influences of podded engines on longitudinal trim,attitude and trajectory responses and maximum directional control power requirement of BWB aircraft are analyzed;third,the changes in the proportional relationships between the takeoff characteristic speeds of the example BWB aircraft are *** view of these variations in directional control power requirement and relationships between takeoff characteristic speeds,new recommendations for airworthiness evaluation are proposed for BWB *** conclusions of this paper are helpful references for configuration design,flight control law design and airworthiness evaluation of BWB aircraft.

关键词： Airworthiness Blended wing body Podded engine Relaxed static stability Stability characteristics

Enhanced wear resistance of NiTi alloy by surface modification with Nb ion implantation

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Rare Metals 2014年第3期33卷 244-248页

作者： Yan Li Fei Zhang ting-ting Zhao Ming Tang Yong liu School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing Key Laboratory for Advanced Functional Materials andThin Film Technology Beijing University of Aeronautics and Astronautics Key Laboratory of Aerospace Advanced Materials and Performance (Beijing University of Aeronautics and Astronautics) Ministry of Education School of Mechanical and Aerospace Engineering Nanyang Technological University

Niobium ion implantation is found to significantly decrease the friction coefficient and improve wear resistance of NiTi shape memory alloy. Scanning electron microscope（SEM） observations indicate that surface grooves formed on NiTi during the mechanical polishing are removed after Nb ion implantation. Dry friction tests show that Nb implanted NiTi samples exhibit a lower friction coefficient, narrower wear tracks, fewer wear debris generated, 46 %-62 % reduction in wear width, and29 %-49 % reduction in wear depth compared with the untreated NiTi. Wear resistance is related to the incident parameters, and the Nb implanted NiTi with the incident dose of 2.5 9 1017ionsácm-2, and incident current of2 mA behaves the best wear performance. The lubricating of Nb2O5, good oxidation resistance of Nb in NiTi, and increased micro-hardness of NiTi are responsible for the enhanced wear resistance.

关键词： NiTi Nb Ion implantation Nano-film Wear

ON POTENT ELEMENTS AND PSEUDO CLEAN RINGS

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数学杂志 2025年第1期45卷 39-47页

作者： DING Yan GAO Han-peng liu Xin-yi YAN Zi-yi ZHANG ting School of Mathematical Sciences Anhui UniversityHefei 230601China

In this paper,potent index of an element and pseudo clean rings are *** properties and examples of pseudo clean rings are *** also show that Zm is pseudo clean for every 2≤m∈Z and pseudo clean rings are ***,we prove... 详细信息

关键词： clean rings strongly J-clean rings pseudo clean rings potent elements

One year results of presbyLASIK using hybrid bi-aspheric micro-monovision ablation profile in correction of presbyopia and myopic astigmatism

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International Journal of Ophthalmology(English edition) 2020年第2期13卷 271-277页

作者： Fang liu ting Zhang Quan liu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CentreSun Yat-sen UniversityGuangzhou 510060Guangdong ProvinceChina

●AIM:To analyze one year clinical outcomes and subjective rating of hybrid bi-aspheric multifocal central presbyLASIK with micro-monovision for correction of presbyopia and myopic astigmatism.●METHODS:Seventy-four eyes of 37 patients consecutively treated with presbyLASIK were *** mean age of the patients was 43.8±3.0 y with a mean spherical equivalent refraction of-5.21±1.87 diopters(D)and mean astigmatism of-0.82±0.64 *** acuity,manifest refraction,contrast sensitivity,aberrometry and patients’subjective rating were evaluated pre-and postoperatively.●RESULTS:At 1 y postoperatively(68 eyes of 34 patients),the mean spherical equivalent(SE)refraction in distance eyes was 0.06±0.05 D,whereas the achieved SE in near eyes was-0.83±0.05 ***-nine percent of eyes were within±0.50 D of target correction of *** binocular mean uncorrected distance visual acuity(UDVA)was 0.00±0.18 logMAR(20/20).Sixty-four percent of patients achieved 0.0 logMAR(20/20)or better of UDVA and 0.1 logRAD or better of UNVA as *** was a binocularly loss of one line CDVA after surgery for only one patient(3%,1/34)and no patient lost 2 *** changes in binocular contrast sensitivity(CS)in all test conditions were not significant at any frequency after *** changes of entire eye total higher order aberrations(tHOA)and spherical aberrations(SA)significantly higher in near eyes than in distance *** overall satisfaction score for surgery was 93±8.●CONCLUSION:The hybrid bi-aspheric multifocal central presby LASIK with micro-monovision appears to be an efficacious option for myopic *** year postoperative outcomes in a relatively young presbyopia population indicate improvements in both far and near vision with high satisfaction.

关键词： presbyLASIK presbyopia monovison myopia

Metalloporphyrin receptors for histidine-containing peptides

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Chinese Chemical Letters 2014年第5期25卷 659-662页

作者： Hui liu Zhan-ting Li Key Laboratory for Green Chemical Process of Ministry of Education School of Chemical Engineering & PharmacyWuhan Institute of Technology State Key Laboratory of Bio-Organic and Natural Products Chemistry Shanghai Institute of Organic ChemistryChinese Academy of Sciences

Two new ditopic metalloporphyrin receptors constructed by combining metalloporphyrin with crown ethers have been prepared and characterized.1H NMR and MS spectra confirmed the complexation of receptor with peptide driven by coordination interaction and hydrogen ***/vis experiments revealed that the receptors exhibited high binding affinity to histidine-containing *** receptors could differentiate short peptides of C-terminal histidine and N-terminal histidine and formed the most stable complexes with tripeptide.

关键词： Metallop or phyrin Crown ether Synthetic receptor Peptide

A Machine Learning Study of Polymer-Solvent Interactions

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Chinese Journal of Polymer Science 2022年第7期40卷 834-842页

作者： ting-Li liu Lun-Yang liu Fang Ding Yun-Qi Li State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China

Polymer-solvent interaction is a fundamentally important concept routinely described by the Flory-Huggins interaction(χ),Hildebrand solubility(Δδ)and the relative energy difference(RED)determined from Hansen solubility in experimental,theoretical and simulation *** we performed a machine learning study based on a comprehensive and representative dataset covering the interaction pairs from 81polymers and 1221 *** regression models provide the coefficients of determination in the range of 0.86-0.94 and the classification models deliver the area under the receiver operating characteristic curve(AUCs)better than *** models were integrated into a newly developed software *** features including Log P,molar volume and dipole are identified,and their non-linear,nonmonotonic contributions to polymer-solvent interactions are *** widely known“like-dissolve-like”rule and two broadly used empirical equations to estimateχas a function of temperature or Hansen solubility are also evaluated,and the polymer-specified constants are *** study provides a quantitative reference and a tool to understand and utilize the concept of polymer-solvent interactions.

关键词： Flory-Huggins interaction Hildebrand solubility Hansen solubility Machine learning Prediction