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THE OCCURRENCE AND DEVELOPMENT OF THE ADVENTITIOUS ROOTS FORMING GREEN SHOOT CUTTING OF LARIX OLGENSIS

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Journal of Northeast forestry university 1993年第2期4卷 64-69页

作者： liu GuifengNortheast forestry university Northeast forestry university China

The experiment with the green shoot cutting propagation of Larix olgensis was made in the Maoer Mountain forestry Farm on July 5, 1990. After the callus formed of the cutting base before adventitious roots came out the materials were collected from the cutting base and fixed in FAA solution. By the paraffin sections and anatomical observatio-n. the results indicted that it needed 40 days from the cutting to the rooting. The induced primordium of the cutting was endogenous in origin, which came from : (1) vascular cambium of the callus, and became roots; (2) meristematic cell population in the intersect between the cambium and xylem ray of the cutting base. There were extruding, crushing process and enzymolysis when the adventitious roots broke through the outer layers in two rooting types.

关键词： Larix olgensis Green shoot cutting Anatomical study

HAPLOID BREEDING OF POPULUS

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Journal of Northeast forestry university 1993年第1期4卷 11-17页

作者： liu YuxiNortheast forestry university Northeast forestry university China

After 14 year's growth observation on the plant growth, it was found that obvious segregation appeared among the haploid pollen plants obtained from anther culture of Populus Xiaohei T.S. Hwany ex C. Wang et Tung in vitro. By vegetative propagation, 19 clones were selected and field contrast test was carried out. Statistical analysis result showed a significant difference in volume production. They are superior clones which could be selected from among the pollen plants for utilization. A haploid breeding procedure is suggested in the paper.

关键词： Populus xiaohe Pollen plant Selection utilization

DECIDUOUS AND DECIDUOUS-EVERGREEN FORESTS IN NORTHEAST CHINA

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Journal of Northeast forestry university 1991年第1期2卷 9-16页

作者： Chou Yiliang liu JianweiNortheast forestry university Northeast forestry university China

Two types of forests in Northeast China is divided in this paper, that is, the deciduous forests in the northern part and the deciduous-evergreen forests in the eastern part. Both distributions of the two types of forests have also been presented. Meanwhile, the development and succession as well as components of forests have been studied in detail. In the end, the vertical distribution of the deciduous forests have been shown, in which, the near-temperate cold temperate deciduous coniferous forests are distributing in the low elevation area between 450m-600m from the northto the south, the typical Siberian cold temperate deciduous coniferous forests are widely distributing from 450m-820m in the north to 600m-1050m in the south, the humid cold temperate deciduous coniferous forests can only be found in high elevation area from 820m-l 100m in the north to 1050m-1380m in the south, the cold temperate deciduous coniferous open forests can seldom appear at the top of a few peaks.

关键词： Deciduous forest Deciduous-evergreen forest Succession Distribution Component

A calibration and compensation method for an industrial robot with high accuracy harmonic reducers

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Science China(Technological Sciences) 2024年第3期67卷 725-739页

作者： ZHAO YiYang liu Xun CAO JiaBin liu JinYu XU Yan YAN WeiXin School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China College of Computer and Control Engineering Northeast Forestry UniversityHarbin 150040China

Industrial serial robots need high stiffness to keep absolute pose accuracy and meet the requirements in practical applications. However, the weak stiffness feature of robot joints and the payloads affected on robot end-effector, which will also increase the pose error of robot. Especially, the existing calibration methods often consider under no-payload condition without discussing the payload state. In this paper, we report a new industrial serial robot composed by a new harmonic reducer: Model-Y, based on high accuracy and high stiffness, and a kinematic parameter calibration algorithm which is based on a harmonic reducer forcedeformation model. To decrease the accuracy effects of payload, an iterative calibration method for kinematic parameters with payload situation was proposed. Simulation and experiments are conducted to verify the effectiveness of the proposed calibration method using the self-developed industrial serial robot. The results show a remarkably improved accuracy in absolute position and orientation with the robot's payload range. The position mean error has 70% decreased to 0.1 mm and the orientation mean error diminished to less than 0.01° after calibration with compensation. Additionally, online linear and circular tests are carried out to evaluate the position error of the robot during large-scale spatial and low-speed continuous movement. The accuracy is consistent with the previous calibration results, indicating the effectiveness and advantages of the proposed strategy in this article.

关键词： industrial serial robot Model-Y harmonic calibration stiffness model online compensation

Understory seedlings of Quercus mongolica survive by phenological escape

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Forest Ecosystems 2024年第2期11卷 236-246页

作者： Shixiong Wu Ying liu Lulu He Wei Zeng Qijing liu College of forestry Beijing Forestry UniversityBeijing100083China

Understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming *** poor regeneration of dominant tree species,however,is one of the biggest challenges it faces at the ***,the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary forests,which contrasts with the extreme abundance of understory seedlings in secondary *** mechanism behind the interesting phenomenon is still *** study used in-situ monitoring and nursery-controlled experiment to investigate the survival rate,growth performance,as well as nonstructural carbohydrate (NSC) concentrations and pools of various organ tissues of seedlings for two consecutive years,further analyze the understory light availability and simulate the foliage carbon (C) gain in the secondary and primary *** suggested that seedlings in the secondary forest had greater biomass allocation aboveground,height and specific leaf area (SLA) in summer,which allowed the seedling to survive longer in the canopy closure *** light availability and positive C gain in early spring and late autumn are key factors affecting the growth and survival of understory seedlings in the secondary forest,whereas seedlings in the primary forest had annual negative carbon *** the growing season,the total NSC concentrations of seedlings gradually decreased,whereas those of seedlings in the secondary forest increased significantly in autumn,and were mainly stored in roots for winter consumption and the following year's summer shade period,which was verified by the nursery-controlled experiment that simulated autumn enhanced light availability improved seedling survival rate and NSC *** conclusion,our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity of high light availability d

关键词： Carbon gain Nonstructural carbohydrate Recruitment Trade-off Biomass allocation

Effects of tree size and organ age on variations in carbon,nitrogen,and phosphorus stoichiometry in Pinus koraiensis

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Journal of forestry Research 2024年第3期35卷 155-165页

作者： Yanjun Wang Guangze Jin Zhili liu Center for Ecological Research Northeast Forestry UniversityHarbin 150040People's Republic of China Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education Northeast Forestry UniversityHarbin 150040People's Republic of China Northeast Asia Biodiversity Research Center Northeast Forestry UniversityHarbin 150040People's Republic of China

Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global ***,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains *** determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast *** factors were also *** results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil *** a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree *** the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric *** results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual *** is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for ***,nutrient storage strategy in older trees and organ fractions are mainly for steady *** results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.

关键词： Tree size Organ age(or root order) Carbon(C) Nitrogen(N) Phosphorus(P) Pinus koraiensis

Quantitative analysis and prediction of the sound field convergence zone in mesoscale eddy environment based on data mining methods

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Acta Oceanologica Sinica 2024年第5期43卷 110-120页

作者： Ming Li Yuhang liu Yiyuan Sun Kefeng liu College of Advanced Interdisciplinary Studies National University of Defense TechnologyNanjing 211101China Jiangsu Ocean university Lianyungang 222061China College of Horticulture forestry Sciences Huazhong Agricultural UniversityWuhan 430070China

The mesoscale eddy(ME)has a significant influence on the convergence effect in deep-sea acoustic *** paper use statistical approaches to express quantitative relationships between the ME conditions and convergence zone(CZ)*** on the Gaussian vortex model,we construct various sound propagation scenarios under different eddy conditions,and carry out sound propagation experiments to obtain simulation *** a large number of samples,we first adopt the unified regression to set up analytic relationships between eddy conditions and CZ *** sensitivity of eddy indicators to the CZ is quantitatively ***,we adopt the machine learning(ML)algorithms to establish prediction models of CZ parameters by exploring the nonlinear relationships between multiple ME indicators and CZ *** the research,we can express the influence of ME on the CZ quantitatively,and achieve the rapid prediction of CZ parameters in ocean *** prediction accuracy(R)of the CZ distance(mean R:0.9815)is obviously better than that of the CZ width(mean R:0.8728).Among the three ML algorithms,Gradient Boosting Decision Tree has the best prediction ability(root mean square error(RMSE):0.136),followed by Random Forest(RMSE:0.441)and Extreme Learning Machine(RMSE:0.518).

关键词： convergence zone mesoscale eddy statistic analysis quantitative prediction machine learning

Peracetic acid catalytic activation using Co3O4 nanocluster decorated graphitic carbon nitride for cefapirin degradation in water

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Science China Technological Sciences 2024年第10期67卷 3103-3115页

作者： YIN ShiMei GAO YiXuan CHEN Long LI Fan liu XiaoNa QI Fei liu Wen Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry University Key Laboratory of Water and Sediment Sciences (Ministry of Education) College of Environmental Sciences and EngineeringPeking University School of Environmental Science and Engineering Taiyuan University of Technology State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems Peking University Beijing National Laboratory for Molecular Sciences Peking University

This study innovated cobalt-based catalytic nanocomposites（CCNs） for the heterogeneous activation of peracetic acid（PAA）,a green and efficient advanced oxidation process for removing antibiotics from *** Co3O4catalysts exhibit limited activity due to stable electronic *** overcome this,CCNs were synthesized using a one-step condensation method,incorporating a size control strategy that anchors Co3O4nanoclusters within 4-5 nm onto six-fold cavity of g-C3N4,simultaneously modifying the coordination environment of *** alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial *** improved performance of CCN2,in particular,is attributed to a shift in the cobalt d band center towards the Fermi level,facilitating electron delocalization and transfer,enhancing Co-O bonding,and accelerating PAA ***2's superior activity,with a cefapirin（CFP） degradation kinetic rate constant(k1=0.760 min-1)～11 times that of PAA direct oxidation(k1=0.070 min-1) and～5 times that of commercial Co3O4/PAA system(k1=0.164 min-1),is due to its ability to generate dominant reactive species for antibiotic degradation,including alkoxy radicals(CH3C（=O）OO·),high valence metal(CoⅣ（=O）2+),and singlet oxygen（1O2）,with the latter two being crucial for the degradation *** degradation of CFP involved three mechanisms,including direct oxidation by PAA,decarboxylation,and open-ring reactions at nitrogen *** research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal,leveraging the strategy of shifting the transition metal d band center.

关键词： peracetic acid Co3O4 nanocluster high valence metal singlet oxygen cefapirin

REFINING OF SULFATE SOAP AND EXTRACTING OF PHYTOSTEROLS

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Journal of Northeast forestry university 1992年第1期3卷 82-88页

作者： Jin Qi liu Zhiqun Northeast forestry university Northeast forestry university China

The sulfatc soap is refined through extracting unsaponifiable neutral substance using ethyl acetate and hcxane-acetone. The content of neutral substance in tall oil decreases from 32.8% to 17.4% and 18%. The acid number of tall oil increases from 119 to 169 and 153. The quality of tall oil is greatly improved. This provides a favorable condition for distillation of tall oil. The unsaponifiable neutral substance from crude sulfate soap mainly consists of tcrpene aldehydes, tcrpcnc alcohols, fatty alcohols and stcrols in which larixol is 26.3% and 18. 5%, stcrols arc 17% and 27.1% separately. The white crystals containing stcrols of 96.9% are obtained by crystallization and rccrystallization. The stcrols arc mainly β-sitostcrol and campcsterol.

关键词： Refining Sulfatc soap Extracting Phytosterol