Cranberry(Oxycoccos)has strong cold resistance,and its fruit has high health value and economic value.In this stud-y,the tissue cultured seedlings of cranberry were used as cuttings to explore the soaking and quick dipping tests of cranberry cuttings under different indole-3-acetic acid(IAA),1-naphthlcetic acid(NAA)and 3-indolebutyric acid(IBA)concentrations,and the effects of different hormone types and concentrations on rooting rate,seedling height growth,biomass and root growth characteristics(including the longest root length,root surface area,average root diameter and average root number).The results showed that,when NAA soaking treatment was 100 and 200 mg/L,the root system grew well,but the longest root length was only(30.77±0.18)cm(NAA 100 mg/L),and the average root diameter was(0.3±0.02)mm.However,the longest root length of cuttings treated with IBA 1000 mg/L per hour was(30.13±3.22)cm,the average root diameter was(0.39±0.04)mm,the root surface area was(1.27±0.01)cm2,and the average number of roots was(128.22±2.38).From this point of view,there was little difference in root growth between the soaking treatment and the rapid soaking treatment,but in general,when the IBA concentration was 1000 mg/L,the rooting rate,was 85% at the highest.Therefore,the quick dipping method was more suitable for the rooting of cranberry tissue culture seed-lings.In this study,the cutting propagation technology of tissue culture seedlings of cranberry was established for the first time,which laid the foundation for large-scale propagation of cranberry.
In response to the slow processing speed and low reconstruction accuracy encountered during the 3D reconstruction of trees,a method for 3D reconstruction of single-tree skeletons using laser point cloud data is proposed.Firstly,a combination filtering method is determined based on the point cloud data type to remove outliers and ground points.Secondly,a hybrid registration algorithm based on ISS(Intrinsic Shape Descriptor)and CPD(Coherent Point Drift algorithm),called IS-CPD(Intrinsic Shape-Coherent Point Drift),is employed to obtain complete point cloud data for individual trees.Finally,a method combining Laplace contraction of point sets and topological refinement is used to obtain the skeleton,and branch models are constructed using cylinders to achieve 3D skeleton reconstruction.Experimental results show that compared to traditional CPD algorithm,the proposed registration scheme im-proves accuracy and execution speed by 50% and 95.8% respectively,with a final reconstruction error of no more than 2.48%.The research demonstrates the effective reconstruction of the 3D skeleton of individual trees,with results close to the original trees,provi-ding a reference for building digital twin environments of forest trees and forestry resource management.
Aiming at the problems of low milling efficiency,low machining precision and high manual labor intensity of the outer frame of passive European-style wood windows,a double end milling machining center for passive European-style wood windows was designed and used for high-efficiency and high-precision milling of the outer frame of passive European-style wood windows.Through the analysis of the milling process of wood windows,the detailed design of the machining center structure was carried out using comput-er-aided design methods.Solidworks software was used for three-dimensional modeling of the machining center,and finite element a-nalysis software was used to analyze the strength and stiffness of the key support parts.Virtual experimental methods was used to verify the machining efficiency of the machining center.The results showed that the theoretical machining efficiency of the machining center was about 400 fans/day,compared with the manual machining efficiency of 350 fans/day,the efficiency was improved by 14.28%,and the maximum stress of the key support parts was far less than the permissible stress of the material,which met the requirements for use.
To investigate the microbial diversity and the main pathogenic microorganisms of Fraxinus mandshurica leaves with dif-ferent degrees of brown spot disease,and to analyze the control methods to maintain the ecological safety and enhance the economic benefits of Fraxinus mandshurica plantation forests,leaves infected with brown spot disease to varying degrees at Maoershan Experimen-tal Forest Farm were collected,and the microbial community structure and species composition of Fraxinus mandshurica leaves were de-termined and analyzed using high-throughput sequencing technology.A total of 1 026 fungal operational taxonomic units(OUT)and 322 bacterial OUTs were obtained before and after the disease in the three groups of samples.Among the bacteria,the phyla Proteobac-teria and Actinobacteriota were the dominant phyla;the genera Sphingomonas,Acidibacter and Bradyrhizobium were the main dominant genera.Among the fungi,the phyla Ascomycota and Basidiomycota were the dominant phyla;the genera Vishniacozyma,Septoria,and Hannaella were the dominant genera.There were no significant differences in bacterial diversity and community structure among the three groups of samples,and significant differences in fungal diversity and community structure.It was preliminarily speculated that the Cercospora was a pathogenic bacterium,but its pathogenicity needed further study.
In order to meet the needs of European wood windows customized size change,a size adaptive positioning clamping de-vice was designed,and the finite element software was used to carry out static analysis of the clamping process of wood windows,ensu-ring that the elastic deformation of wooden windows was within a reasonable range while meeting the clamping requirements.At the same time,in order to meet the lightweight design requirements,the topology optimization design of the press roller connecting frame was carried out.The structure of the press roller connecting frame was improved according to the topology optimization results,and the static analysis and verification of the optimized model were carried out,and the optimized workpiece was finally obtained.The results showed that the weight of the press roller connecting frame decreased obviously after optimization,which meets the relevant requirements.
Light detection and ranging(LiDAR),as an active remote sensing technology,is able to obtain information on the spa-tial structure of forests by emitting laser energy and receiving the return information,however,when used alone there is a scanning blind spot and a complete 3D point cloud of forest trees cannot be obtained.Based on this,this study proposes a method for estimating the structural parameters of a individual tree by fusing UAV and TLS LiDAR point clouds,and realizes point cloud fusion by using a registration method based on ground features and tree position relationships.Based on this,an improved K-means hierarchical cluste-ring segmentation algorithm is proposed to complete the individual tree segmentation,and then based on the segmented individual tree point cloud,the axis-aligned bounding box algorithm and the least squares fitting circle method are used to extract the height of the in-dividual tree and diameter at breast height respectively,and finally estimate the biomass of a individual tree through the biomass allo-metric growth equation.The research results show that the Coefficient of Deter mination(R2)of tree height,diameter at breast height and individual tree biomass of Quercus mongolica sample plots are 0.84,0.93,0.91 respectively,and the root mean square error(RMSE)of individual tree structure parameters are 0.75 m,0.96 cm,26.31 kg/plant respectively.The R2 of tree height,diameter at breast height and individual tree biomass in the Pinus sylvestris plot are 0.92,0.96,and 0.95,respectively,and the corresponding root mean square errors are 0.43 m,1.06 cm,and 26.12 kg/plant,respectively.The fusion of UAV and TLS LiDAR point cloud pro-vides a reliable data basis for the rapid and complete acquisition of forest structure information,and provides a strong technical support for the deep forestry application of joint multi-source LiDAR technology.
To study the ultrasonic-assisted extraction(UAE)process of oil and proanthocyanidins from Pinus koraiensis seed scales,a single-factor analysis experiment was conducted with oil and proanthocyanidins yield as response values.The Box-Behnken response surface optimization method was applied to determine the optimal process conditions,which were as follows:67% ethanol aqueous solution,liquid material ratio of 10 ∶ 1 mL/g,tea saponin mass concentration of 0.3%,power of 100 W,time of 20 min,water bath temperature of 50℃,expected yield of 21.24% and 3.03 mg/g respectively,actual yield of 20.86% and 2.98 mg/g,rela-tive error of 1.79% and 2.97%.Comparison analysis revealed that UAE reached equilibrium in a relatively short time.UAE treatment increased the specific surface area of the seed powder in the solution.The order of DPPH and ABTS+ free radical scavenging activities for oil and proanthocyanidins was proanthocyanidins,Ve and oil,indicating that Pinus koraiensis seed scales oil and proanthocyanidins possess good antioxidant capabilities.The use of tea saponin as an inducer for UAE extraction of oil and proanthocyanidins from Pinus koraiensis seed scales demonstrated advantages.These research findings provide a theoretical basis for the in-depth development of Pinus koraiensis seed scales.
In order to better analyze the physiological process of forest vegetation stress and establish an effective forest monitoring system,remote sensing health estimation of vegetation stress in the Kunyu Mountain area was carried out using GF-5 hyperspectral da-ta.GF-5 hyperspectral data enables non-destructive monitoring of important indicators such as chlorophyll,carotenoids,and anthocy-anin content to reflect vegetation health,making it possible for the dynamic health monitoring system applicable to the current research area.The results showed that the average health level of mixed forests was the highest,followed by deciduous broad-leaved forests,and the average health level of evergreen and deciduous coniferous forests was equivalent.The average health level of forest on the sun-ny slope was the highest,followed by the average health level of forest on the semi shaded and semi sunny slopes,with the lowest health level of forest on the shaded slope.There was a certain correlation between vegetation health and soil type,a positive correlation with sandy soil,and a negative correlation with silt and clay.Research had shown that the use of remote sensing indices related to dif-ferent types and stresses in vegetation canopy can quantitatively represent the special state,biophysical,and biochemical characteristics of vegetation,enabling the investigation,monitoring,and management of forest resources.
To investigate the shear behavior of ultra-high performance concrete(UHPC)dry joints,based on finite element analy-sis theory,the UHPC dry joints were modeled and analyzed in the general finite element analysis software(ABAQUS),and the me-chanical performance of the UHPC joints under direct shear load was obtained.Using existing experimental data,the applicability and accuracy of the American Association of State Highway and Transportation Officials(AASHTO)section bridge design code and UHPC dry joint shear strength calculation formula proposed by many scholars were evaluated.At the same time,the formula of direct shear ca-pacity of UHPC dry joint was obtained by fitting the collected measured data.The results showed that the ABAQUS model based on the concrete plastic damage theory can simulate the direct shear force characteristics of UHPC dry joints.The average value of the ratio be-tween the model test results and the finite element results was 0.970,and the coefficient of variation was 0.107.American AASHTO formula and Spanish ATEP formula based on ordinary concrete structure can not accurately predict the shear capacity of UHPC dry joint,and the calculation results were not safe.The prediction result of UHPC joint calculation formula proposed by scholars was con-servative,and the economy was poor.The calculation formula given in this study was accurate and can provide reference for joint de-sign and calculation of actual segment UHPC fabricated bridge.
In order to comprehend the root and needle N,P and K biochemical stoichiometry characteristics of Pinus massonana,judge its nutrient restriction and utlization,this results provide technical support for fertilization management in the process of P.mas-sonana seedling cultivation.The fertilization experiment of P.massonana seedlings was carried out to analyze the effect of P fertilizer on the N,P and K mass fractions of roots and needles of one-year-old P.massonana seedlings in different seasons.The phosphorus fertilizer used calcium magnesium phosphorus fertilizer(P has an effective rate of 14%).Four levels of 0,50,100 and 200(P1,P2,P3,P4)was designed in this experment.The results showed that the content of N,P,K and their ecological stoichiometry were not significantly affected by different P application(P>0.05),but it was significantly different in different seasons(P<0.05).In the spring of the following year after fertilization,under P2 treatment N ∶ P was17.2,which was greater than 16.The roots and needles of P.massoniana in other treatments had N ∶ P<14,and the needles were treated with P fertilizer in the later stage(winter,spring of the following year)with N ∶ P higher than the CK.The ratio of N ∶ K was 2.83-29.30,both greater than 2.1,the ratio of P ∶ K was 0.68-3.82 and K ∶ P was less than 3.4.The ratio of N ∶ K of roots and needles of P.massoniana in P2 treatment was less than the CK,and the ratio of N ∶ K of needles in P3 and P4 treatments was higher than the CK.Different treatments showed that the growth process of P.massonana was limited by N and K elements,and the restriction of N and K elements was aggravated by the increase of P concentration after applying P fertilizer,especially when applying high concentration P fertilizer(P3,P4).The results of this study showed that a large amount of phosphorus(P3,P4)increased the restriction of N and K elements in the growth of P.massonana.In the cultivation of P.massonana seedlings,N,P,and K can be applied in a suitable proportion to promote seedling growth.Further research is needed on the limiting standards of N,P,and K measurement characteristics of different organs on the growth of P.massonana.
In order to solve the problem of complex effects between the reinforced soil interface in reinforced soil structures,the paper adopted the micro-unit force balance method of the reinforcing material,considered the effects of shear stiffness and displace-ment,and derived the formula for the peak tensile force of reinforced soil.The tensile forces and displacements of the reinforcement at each location were predicted if the tensile forces do not exceed the peak pullout force.The maximum peak tensile force was deter-mined,and the effect of effective reinforcement length and shear stiffness on the displacement of reinforcement and its variation rule were investigated within the range of maximum peak tensile force.The results showed that when the peak tensile force was constant,the effective reinforcement length and shear stiffness had a significant effect on the peak tensile force,while the elastic modulus had a rela-tively small effect on the peak tensile force.The displacement of the reinforcement decreased nonlinearly with the increase of the effec-tive reinforcement length and shear stiffness.The calculation results based on the formula of peak tensile force at the interface of rein-forced soil were compared with the test results.It was found that the maximum peak tensile force between the two was not different,and the results agreed well.The research results can provide some theoretical reference for reinforced soil engineering.
Taking the MODIS NDVI data,land use data and meteorological data of Heilongjiang Province from 2000 to 2020 as the research object,three main types of land cover,farmland,forest land and grassland,and two climate factors,temperature and precipi-tation,were extracted to explore the spatial and temporal changes of the vegetation cover index(NDVI)in Heilongjiang Province in the past 21 years and the relationship between vegetation changes and climate factors.Using Theil-Sen and Mann-Kendall trend tests,co-efficient of variation,Hurst index,and correlation analysis methods,Using Theil Sen trend estimation,Mann Kendall trend test,coef-ficient of variation,Hurst index,and correlation analysis methods,this study analyzed the spatiotemporal variation characteristics of NDVI in different seasons and vegetation types in Heilongjiang Province from 2000 to 2020,as well as the relationship between NDVI and temperature and precipitation.The results indicated that,1)in the past 21 years,the average annual NDVI of the growth season in Heilongjiang Province had been 0.91,and the high vegetation coverage area was mainly distributed in the central and southern parts of Heilongjiang Province.There were obvious seasonal characteristics of NDVI fluctuations within the year.2)The NDVI in the prov-ince was relatively stable,with the highest stability in grassland NDVI.3)In the past 21 years,the overall NDVI in Heilongjiang Province had shown a significant upward trend,with a rate of 4.7% increase every 10 years.The regions showing a significant increas-ing trend accounted for 35.55% of the province's area(P<0.05),mainly distributed in the central,western,and northern parts of Heilongjiang Province.4)In the future,the overall trend of NDVI in Heilongjiang Province will mainly be continuous changes in the same direction(69.5%),with 35.33% likely to develop towards a malignant direction of degradation and 43.6% likely to develop to-wards a benign direction of improvement.5)The vegetation and seasons in Heilongjiang Province were positively correlated with pre-cipitation and temperature(P<0.05).As a result,the overall vegetation coverage level in Heilongjiang Province has been good in the past 21 years and shows an improvement trend.The development trend of future vegetation cover changes is mainly towards benign im-provement,and temperature and precipitation have a positive correlation with vegetation change.
To reveal the response degree of ring width for earlywood,latewood,and ringwood of Larix olgensis plantation to climate change,135 sample trees from 27 sample plots in Maoershan Experimental Forest Farm of Northeast Forestry University were taken as data sources,based on the establishment of tree ring chronology,the correlation analysis was used to quantify the relationship between ring width earlywood,latewood,and ringwood and climate factors.Results showed that the ring width of L.olgensis can be divided into two distinct time periods on the time scale.During 1974-1985,the tree growth was mainly affected by the temperature in spring and autumn,while from 1986 to 2019,it was mainly affected by the temperature in summer.During 1974-1985,the highest and lowest temperaturesin winter and spring,especially in January,February,April and May of the previous year and that year,had a negative correlation(P<0.05)with the growth of earlywood and ringwood,but a positive correlation with the growth of latewood(P<0.05).The period in April and May of the previous year and the spring of that year had a negative correlation with the growth of ring width of earlywood(P<0.05).From 1986 to 2019,the highest and lowest temperatures in summer,especially in June and July of the previous year and that year,had a significant positive correlation with the ring width of latewood(P<0.05).The average temperature in sum-mer,especially in July of the previous year and that year,had a significant positive correlation with the growth of latewood(P<0.05),but a significant negative correlation with the growth of ring width of earlywood and ringwood(P<0.05).On the whole,the tempera-ture in the growing season,especially the minimum temperature and average temperature,are the main factors limiting the growth of earlywood and latewood of L.olgensis plantation,the effect of precipitation on the growth ofearlywood and latewood is not significant.
Leaf area index(LAI)is the key driving data of BEPS model,and it is important to obtain high accuracy LAI for re-gional forest ecosystem carbon cycle,however,the MODIS LAI products used in most current studies lack credibility.To this end,this study constructed a data assimilation system based on LAI dynamic model,PROSAIL radiative transfer model and Hierarchical Bayes-ian Network(HBN)to obtain LAI data with a spatial resolution of 20 m to drive the BEPS model and simulate the vegetation net prima-ry productivity(NPP)of Saihanba Mechanical Forest during 2011-2021,and the spatial and temporal variation of NPP and the influ-encing factors of NPP were analyzed.The results showed that the high-resolution LAI data obtained based on Bayesian assimilation method greatly improved the accuracy of MODIS LAI products;the correlation between the simulated forest NPP obtained from BEPS model driven by assimilated LAI data and the NPP calculated from the sample plots was high(R2=0.77);the mean value of vegeta-tion NPP in Saihanba Mechanical Forest during 2011-2021 was 307.4 g/(m2·a),and the NPP of forest showed a steady growth trend;the simulated NPP of different vegetation types were different,and the simulated NPP of coniferous,deciduous and mixed for-ests were 484.9,402.4,287.9 g/(m2·a);the correlation between vegetation NPP and temperature factor was high,and the bias correlation coefficient was 0.2-0.8,while the correlation between vegetation NPP and precipitation was relatively low in general,with bias correlation coefficients of-0.3-0.4.The influence of precipitation on vegetation NPP was low in this region,and temperature was the dominant factor of NPP variation in this region.In this study,high spatial resolution LAI data were obtained to provide a basis for accurate spatial and temporal simulation of the carbon cycle in forest ecosystems.
To establish the rutting prediction model of asphalt pavement under layered variable modulus,the deviation of perma-nent deformation prediction of asphalt pavement caused by dynamic modulus change was corrected.Based on the asphalt mixture dy-namic modulus test and laboratory triaxial dynamic creep test,the correlation between the asphalt mixture dynamic modulus(| E∗ |)and its high-temperature deformation resistance was verified.Abaqus finite element software was used to analyze the dynamic modulus and vertical compressive stress of asphalt pavement with depth and temperature at different times,and the correction factor(m)of ver-tical compressive stress of each sub layer under different dynamic modulus was proposed.According to the idea of' sub layer deforma-tion superposition',a rutting prediction model of layered variable modulus asphalt pavement was established by using SPSS software re-gression analysis,which included temperature,asphalt layer thickness,vertical compressive stress,correction factor,load action times and other factors.The results showed that the established rutting prediction model can more accurately predict the permanent deforma-tion of asphalt pavement,improve the rutting prediction accuracy of middle and lower layers by 6.03% and 10.34%,respectively,and improve the overall asphalt layer by 5.19%.
The active traffic control in the merging area,which takes ramp arrival control as the main body,is the main means adopted by the expressway and urban expressway to improve the capacity and traffic safety of the weaving area.In this study,the his-torical real traffic data and the optimized theoretical model of speed fluctuation are used to build the vehicle arrival model in the process of congestion and queue weaving,and the optimal control scheme under the mixed control decision is quantitatively analyzed.Through the optimized simulation platform,the vehicle trajectory,distribution and conflict status are obtained,and the actual effect of the con-clusion is verified.This study takes Qinhong Interchange as an example to demonstrate the model test,and verify the optimization effect of ramp single control and ramp main line mixed control under the optimization effect.The results show that the conflict under ramp control is reduced by 52.5% and the vehicle delay is increased by 20.5% compared with the uncontrolled state.The conflict and vehi-cle delay under hybrid control are reduced by 68.1% and 12.0%,respectively.It can be seen that the control model has obvious opti-mization effect on ramp traffic safety and efficiency.One of the most effective control strategies is the ramp mainline mixed control,which leads to significant improvements in ramp traffic efficiency and traffic safety.
In order to explore the effect of heat treatment of vegetable oil wax on the physical properties and dimensional stability of wood of different tree species,Abies nephrolepis Maxim.,Larix gmelinii and Diospyros celebica were taken as the research objects,and the independently prepared vegetable oil wax solution was used as the heating medium.The wood was heat treated at different tempera-tures(140,170,200℃)for 4 hours,and then the vegetable oil wax was fully cooled to ensure that it entered the interior of the wood.The internal structure was observed by scanning electron microscope.The results showed that the room temperature cooling stage was the key of wood oil wax heat treatment.At this stage,a large amount of vegetable oil wax entered the interior of wood,which was mainly reflected in the change of wood specimen weight percentage gain(WPG).The maximum color change(ΔE∗)of three kinds of wood after combined heat treatment with vegetable oil and wax were 48.24,40.67,5.95.The surface hydrophobicity was improved steadily,and the water contact angle(WCA)was increased to about 70°.The tangential and radial moisture expansion rates and vol-ume expansion rates of different tree species were reduced to varying degrees,and the anti swelling efficiency(ASE)was effectively improved,with the maximum increase of 49.64%,48.24% and 38.86% for the three kinds of wood,indicating that vegetable oil wax heat treatment can improve the dimensional stability of wood.
In order to solve the problem of biomass change caused by the change of the characteristic parameters of single wood caused by the natural growth of forest stand and the pruning of artificial shears,terrestrial laser scanning(TLS)and aerial vehicle laser scanning(UAV-LS)data were taken as data sources,through the single-wood segmentation method,the single-wood recall rate of UAV-LS data based on the high-precision digital elevation model provided by terrestrial laser scanning was improved.Based on the UAV-LS data,the extraction and consistency evaluation of individual tree height were carried out.The optimized biomass model was used to calculate the individual tree biomass of each tree species in 2022 and 2023 using tree height parameters.The results showed that the combined TLS data can increase the recall rate of UAV-LS data from 60.0% to 73.1%.The tree height parameters in 2022 and 2023 were extracted to obtain the natural growth and pruning status of trees in the past two years.The consistency correlation coef-ficient(Concordance correlation coefficient,CCC)of tree height consistency evaluation was 0.98 and the root mean square error(RMSE)was 1.12 m.And the biomass of single wood and stand biomass in the past two years was calculated and the stand biomass was 77.39 and 81.56 t/hm2 per unit area in 2022 and 2023,respectively.This study confirmed that it was feasible to obtain tree height time series dynamic calculation of individual tree biomass of each tree species by using UAV low-altitude remote sensing data in the research area and can grasp the biomass changes caused by natural growth and artificial pruning of forest stands.
The quality of veneer determines the grade of veneer wood-based panels and the treatment of defects on veneer becomes an important part of wood processing.In order to deal with veneer defects and improve wood utilization,an image inpainting method of venerr defect based on match attention is proposed.The method proposes a match attention module to acquire features at a distance to enhance the accuracy of the model and uses a double convolution module that captures multi-scale contextual information.Then region normalization is used throughout the network to avoid mean and variance bias.Peak signal-to-noise ratio(PSNR)and structural simi-larity index(SSIM)are used as evaluation indicators.The results show that the PSNR of the improved method reaches 28.48,and the SSIM reaches 0.91.Compared to the globally and locally consistent image completion(GL)method,the PSNR and SSIM are im-proved by 1.03% and 0.05%,respectively.This method can achieve consistent effect in structure and texture,which providing guid-ance for the inpainting of the veneer defects.
In order to improve the utilization value of straw,a series of carrageenan/straw lignin composite films(C/L composite films)with different SL contents were prepared by extracting lignin from straw(SL)mixed with carrageenan and sorbitol.The effects of lignin amount within the film on the structure and performance were studied through structure characterizing and performance testing of the film.The results showed that SL can effectively enhance the mechanical properties of the film,improve its hydrophobicity,in-crease its haze,and endow the film with antioxidant and UV shielding properties,but it had little effect on the thermal stability of the film.The film exhibited a uniform and dense structure at the SL addition above 8%,proving a better compatibility between them.And FTIR results indicated the hydrogen bond was the main combining force.The film blocked almost all UV light when the addition amount of SL was 10%.When the addition amount of SL was 12%,the mechanical properties of the film were the best,with a tensile strength of 22.97 MPa and elongation at break of 30.40%.When the addition amount of SL was 14%,hydrophobicity of the film was the best,with a minimum water vapor permeability value of 6.78×10-11 g m-1 s-1 Pa-1,contact angle of water increased from 28° to 79°.The antioxidant capacity of the film increased with the increase of SL addition amount.The DPPH(1-1-Diphenyl-2-Picrylhydrazyl radi-cal)radical scavenging rate of the prepared films enhanced from 0 to 23.39% as the SL addition was 16%.
