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Photosynthesis adaption in Korean pine to gap size and position within Populus davidiana forests in Xiaoxing’anling, China

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Journal of Forestry Research 2022年第5期33卷 1517-1527页

作者： Xuannan Li Yahui Wang Zhihui Yang Ting Liu Changcheng Mu Center for Ecological Research Northeast Forestry UniversityHarbinHeilongjiang 150040People’s Republic of China

Forest gaps restrict the restoration of temperate secondary forest to broad-leaved Korean pine forest in zonal climax vegetation by affecting the growth of Korean pine(Pinus koraiensis).However,the photo synthetic adaptability of Korean pine to gap size and position within the gap is *** order to explore the adaptability of young Korean pine(35 years) to different gap sizes in Xiaoxing’anling,photo synthetic capacity and microenvironmental factors(leaf temperature,light transmittance) of Korean pine needles in three positions in the gap(central,transition,and edge areas) were *** gaps were identified in the secondary Populus davidiana forest:a large 201 m^(2) gap,a middle 112 m^(2) gap,and a small 50 m^(2) gap;12 m^(2) of the understory was sampled as a *** results show that:(1) maximum net photosynthetic rate(P_(max)) in needles of Korean pine growing in the large gap was higher than in the small gap,and P_(max) in the centre in the same gap was higher than in the transition and edge areas;(2) light saturation point(LSP) and photosynthetic quantum yield(AQY)of needles in the large gap were higher than in the small gap,while the light compensation point(LCP) and chlorophyll contents of needles were lower in the small gap;and,(3)P_(max) had a significant positive correlation with temperature and light *** is suggested that the larger the gap in secondary Populus davidiana forests,the greater the change in light intensity and temperatures,the stronger the light adaption of Korean pine needles and the higher the photosynthetic ***,in the recovery of broadleaved/Korean pine forests,suitable gaps should be created and gap microhabitats fully utilized to accelerate the restoration process.

关键词： Pinus koraiensis gap size Position in the gap Maximum net photosynthetic rate

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Effect of gap size on Coating Extrusion of Pb-GF Composite Wire by Theoretical Calculation and Experimental Investigation

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Journal of Materials Science & Technology 2005年第5期21卷 729-732页

作者： Wenbin FANG , Hongfei SUN, Erde WANG and Yaohong GENGSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

A new method using lead coated glass fiber to produce continuous wire for battery grid of electric vehicles （EVs） and hybrid electric vehicles （HEVs） was introduced. Under equal flow, both the maximum and minimum theoretical value of gap size were studied and estimation equation was established. The experimental results show that the gap size is a key parameter for the continuous coating extrusion process. Its maximum value （Hmax） is 0.24 mm and the minimum one （Hmin） is 0.12mm. At a gap size of 0.18 mm, the maximum of metal extrusion per unit of time and optimal coating speed could be obtained.

关键词： Lead Glass fiber Composite wire Extrusion gap size

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Optimization analysis on gap size of molding for Pb-GF composite wire

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Journal of Central South University of Technology 2005年第1期12卷 17-21页

作者：房文斌孙宏飞耿耀宏王尔德韩飞 School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001China Center for Composite Materials and Structure Harbin Institute of Technology Harbin 150001China

Under the condition of equal flow, the maximum and minimum theoretical values of gap size were studied and an estimation equation was established for the clad extrusion of the brittle core cladded by plastic metal materials. The results show that the gap size is a key parameter for the continuous clad extrusion and the molding speed. Its maximum value (Hmax) is 0.24mm and the minimum one (Hmin) is 0.12mm. At a gap size of 0.18mm, the maximum of metal extrusion per unit of time and the optimal coating speed can be obtained.

关键词： lead glass fiber composite wire extrusion gap size

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Effect of gap size on microstructure of transient liquid phase bonded IN-738LC superalloy

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Transactions of Nonferrous Metals Society of China 2016年第2期26卷 437-447页

作者： Vahid MALEKI Hamid OMIDVAR Mohammad-reza RAHIMIPOUR Department of Mining and Metallurgical Engineering Amirkabir University of Technology (Tehran Polytechnic) Department of Ceramic Materials and Energy Research Center

In order to investigate the microstructure evolution and gain complete isothermal solidification time, transient liquid phase （TLP） bonding of IN-738LC superalloy was carried out using powdered AMS 4777 as the filler metal. The influence of gap size and bonding time on the joints was investigated. For example, complete isothermal solidification time for 40μm gap size was obtained as 45 min. In the case of lack of completion of isothermal solidification step, the remained molten interlayer cooled in the bonding zone under non-equilibrium condition andγ–γ′ eutectic phase formed in that area. The relationship between gap size and holding time was not linear. With the increase in gap size, eutectic phase width became thicker. In the diffusion affected zone, a much larger amount of alloying elements were observed reaching a peak. These peaks might be due to the formation of boride or silicide intermetallic. With the increase in gap size, the time required for bonding will increase, so the alloying elements have more time for diffusion and distribution in farther areas. As a result, concentrations of alloying elements decreased slightly with the increase in the gap size. The present bi-phasic model did not properly predict the complete isothermal solidification time for IN-738LC-AMS 4777-IN-738LC TLP bonding system.

关键词： IN-738LC superalloy transient liquid phase (TLP) bonding gap size complete isothermal solidification

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Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve(Ghana)

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Journal of Forestry Research 2022年第4期33卷 1157-1174页

作者： Maame Esi Hammond Radek Pokorný Simon Abugre Augustine Gyedu Department of Silviculture Faculty of Forestry and Wood TechnologyMendel University in BrnoZemědělská361300 BrnoCzech Republic Department of Forest Science School of Natural ResourcesUniversity of Energy and Natural ResourcesP.O.Box 214SunyaniGhana Forest Services Division(FSD) P.M.BKumasiGhana

Subri River Forest Reserve(SR)is the most extensive forest area in Ghana with an accompanying rich floral *** the years,logging from both legally prescribed and illegal operations remain the predominant forest disturbance in *** creation following logging is crucial in determining tree species composition and ***,the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and,again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in *** gaps were randomly selected:4 each were grouped into small size(≤200 m^(2)),medium size(201–300 m^(2)),and large size(≥300 m^(2)).Data were gathered from 1 m^(2) circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W *** diversity differed significantly between gap *** diversity indices were measured in large size *** sizes shared similar *** were significant differences among various height groupings of tree species across all three gap *** preferred medium to large size gaps,while shadetolerant tree species preferred small size gaps for their *** and Lower Risk Near Threatened tree species under Conservation Status and,Premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and ***,we recommend the single tree-based selective logging for ensuring creations of small to medium size(200–300 m^(2))gaps through adjustments to the logging permit process,revision of Allocation Quota Permit,strict adherence to the 40-year polycyclic selection system,along with more dedicated enforcement and *** along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservat

关键词： Conservation status gap size Diversity Logging Natural regeneration Subri River Forest Reserve Tree species Utilisation status

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Effects of gaps on regeneration of woody plants: a meta-analysis

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Journal of Forestry Research 2014年第3期25卷 501-510页

作者： Jiaojun Zhu Deliang Lu Weidong Zhang State Key Laboratory of Forest and Soil Ecology Qingyuan Experimental Station of Forest Ecology Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

Forest gaps, openings in the canopy caused by death of one or more trees, have a profound effect on forest regeneration and drive the forest growth cycle. It is therefore necessary to understand the effects of forest gaps on regeneration for modern forest management. In order to provide a quantitative assessment of the effects of forest gaps on regen-eration of woody plants, we conducted this review of gap effects on woody plant regeneration on the basis of 527 observations from 42 indi-vidual papers, and reported the results of these data in a meta-analysis. Overall, densities of regenerated woody plants were significantly greater （359%） in forest gaps than on the closed-canopy forest floor. The regen-eration density in gaps of plantation forests was significantly greater （P＆lt;0.05） than that of natural forest because the regeneration in gaps of plan-tation forests was improved by both gap effects and experimental meas-ures. Similarly, in comparison to natural gaps, regeneration was better enhanced in artificial gaps. Regeneration density exhibited a significantly positive correlation with gap size, but a negative correlation with gap age because the gap size decreased with increasing gap age. Shade tolerance of woody plants affected regeneration density in gaps and understory. Average regeneration density of shade-tolerant species exhibited a sig-nificantly positive response to gaps but densities remained lower in total than those of intermediate and shade-intolerant species. gap effects on regeneration decreased in response to increasing temperature and pre-cipitation because of the limiting effects of lower temperature and moisture on woody plant regeneration. In summary, forest gaps enhance woody plant regeneration, and the effects of gaps varied by forest type, gap characteristics, environmental factors and plant traits. The results of this meta-analysis are useful for better understanding the effects and roles of gaps on forest regeneration and forest manage

关键词： forest gap regeneration disturbance gap size gap age,shade tolerance

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