What diameter?What height?Influence of measures of average tree size on area-based allometric volume relationships

Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume equation.When density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height measure.When density was not included(Volume=f(Diameter,Height)),the opposite was true.For models with density included,moment-based estimators of stand diameter and height performed better than all other measures.For models without density,largest tree estimators of stand diameter and height performed better than other measures.The overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.

Characterizing permeability-porosity relationships of porous rocks using a stress sensitivity model in consideration of elastic-structural deformation and tortuosity sensitivity

Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource mining.More and more studies focus on how to construct stress sensitivity models to describe the relationship and obtain a comprehensive stress sensitivity of porous rock.However,the limitations of elastic deformation calculation and incompleteness of considered tortuosity sensitivity lead to the fact that the existing stress sensitivity models are still unsatisfactory in terms of accuracy and generalization.Therefore,a more accurate and generic stress sensitivity model considering elastic-structural deformation of capillary cross-section and tortuosity sensitivity is proposed in this paper.The elastic deformation is derived from the fractal scaling model and Hooke's law.Considering the effects of elastic-structural deformation on tortuosity sensitivity,an empirical formula is proposed,and the conditions for its applicability are clarified.The predictive performance of the proposed model for the permeability-porosity relationships is validated in several sets of publicly available experimental data.These experimental data are from different rocks under different pressure cycles.The mean and standard deviation of relative errors of predicted stress sensitivity with respect to experimental data are 2.63%and 1.91%.Compared with other models,the proposed model has higher accuracy and better predictive generalization performance.It is also found that the porosity sensitivity exponent a,which can describe permeability-porosity relationships,is 2 when only elastic deformation is considered.a decreases from 2 when structural deformation is also considered.In addition,a may be greater than 3 due to the increase in tortuosity sensitivity when tortuosity sensitivity is considered even if the rock is not fractured.

Elucidating the structure-activity relationship of Cu-Ag bimetallic catalysts for electrochemical CO_(2) reduction

Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO_(2) reduction reactions,where understanding the structure-activity relationship is essential for catalyst design.Herein,we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu nanowires.When tested in a flow cell,the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54%for ethylene production,much higher than the catalyst with Ag nanoparticles on the top.The catalysts were further studied in the H-cell and zero-gap MEA cell.It was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic catalysts.Our work elucidates the structure-activity relationship of bimetallic catalysts for CO_(2) reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.

The Relationship between Father-Love Absence and Loneliness:Based on the Perspective of the Social Functionalist Theory and the Social Needs Theory

Fathers play an important role in adolescents’development,which is significant for their development and influences their mental health,including feeling of loneliness.However,the effects and mechanisms of father-love absence on individual loneliness are not clear.Based on the social functionalist theory and the social needs theory,this study examines the influence of individual fatherlove absence on loneliness and its underlying mechanisms.A questionnaire survey was administered to 319 junior high school students and 1,476 high school students.The results showed that adolescents with father-love absence had higher levels of loneliness,and that father-love absence affected loneliness levels through mediating pathways of individual gratitude,peer relationships,and gratitude to peer relationships.This study not only confirms the negative effects of father-love absence on adolescents’loneliness,but also explains the mediate roles of individual gratitude and peer relationships.It enriches the theoretical system related to family education and has important theoretical and practical implications for further interventions on adolescents’mental health from the perspective of fatherless parenting.

PCB CT Image Element Segmentation Model Optimizing the Semantic Perception of Connectivity Relationship

Computed Tomography(CT)is a commonly used technology in Printed Circuit Boards(PCB)non-destructive testing,and element segmentation of CT images is a key subsequent step.With the development of deep learning,researchers began to exploit the“pre-training and fine-tuning”training process for multi-element segmentation,reducing the time spent on manual annotation.However,the existing element segmentation model only focuses on the overall accuracy at the pixel level,ignoring whether the element connectivity relationship can be correctly identified.To this end,this paper proposes a PCB CT image element segmentation model optimizing the semantic perception of connectivity relationship(OSPC-seg).The overall training process adopts a“pre-training and fine-tuning”training process.A loss function that optimizes the semantic perception of circuit connectivity relationship(OSPC Loss)is designed from the aspect of alleviating the class imbalance problem and improving the correct connectivity rate.Also,the correct connectivity rate index(CCR)is proposed to evaluate the model’s connectivity relationship recognition capabilities.Experiments show that mIoU and CCR of OSPC-seg on our datasets are 90.1%and 97.0%,improved by 1.5%and 1.6%respectively compared with the baseline model.From visualization results,it can be seen that the segmentation performance of connection positions is significantly improved,which also demonstrates the effectiveness of OSPC-seg.

Modern pollen-vegetation relationships along altitudinal vegetation belts in the Leigong Mountain of southwestern China

Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen records.This study,conducted in Leigong Mountain on the YunnanGuizhou Plateau of southwestern China,involved the collection of 35 surface soil samples from diverse vegetation communities along an elevational gradient ranging from 1210 to 1875 meters.The results reveal a close correspondence between modern pollen assemblages and vegetation zones.Principal Component Analysis(PCA)results indicate that pollen assemblages can effectively distinguish between subtropical montane evergreen broad-leaved forest(SEBF)and subtropical montane deciduous broadleaved forest(SDBF).However,both SEBF and SDBF show significant overlap with subtropical montane evergreen-deciduous broad-leaved mixed forest(SEMF).Detrended Correspondence Analysis(DCA)results clearly distinguish the three vegetation zones,and the first axis of DCA shows a significant positive correlation with elevation(p<0.01,R=0.48).Discriminant Analysis(DA)successfully assigns 94.4%of the modern pollen samples to their respective vegetation zones.Pollen taxa such as Impatiens,Astertype,and Rosaceae exhibit significant indicative capabilities for the SEBF zone,effectively distinguishing this vegetation zone from others.Pinus and Alnus display overrepresentation in the Leigong Mountain region,while Quercus(D,deciduous-type)and Poaceae exhibit high representation in the SEBF zone.In the SEBF zone,both pollen diversity and richness are the lowest.Our study reveals the complex relationship between the richness and diversity of pollen and vegetation.The diversity and richness of tree and shrub pollen are found to be lower than those of the corresponding plants.The pollen-vegetation relationship elucidated in this study serves as a critical reference for reconstructing ancient environments from fossil pollen retrieved in this region.

The Risk Role of Defeat on the Mental Health of College Students:A Moderated Mediation Effect of Academic Stress and Interpersonal Relationships

Background:College students face significant academic and physiological changes,making them more susceptible to psychological issues such as depression,self-injury,and suicidal ideation.Feelings of defeat can exacerbate these risks by increasing academic stress.However,interpersonal relationships can moderate the impact of academic stress on students’mental health.Utilizing the presage–process–product model,this study aims to empirically investigate how feelings of defeat influence depression,self-injury,and suicidal ideation among college students.Additionally,it explores the mediating role of academic stress and the moderating role of various types of interpersonal relationships.Methods:A total of 1612 college students(750 females,862 males,mean age=19.64±0.62 years)were recruited through cluster sampling.Data were collected via offline questionnaires administered by a trained psychology teacher and a postgraduate student,ensuring high reliability with two examiners per class.Latent profile analysis(LPA)was used to examine the impact of defeat on mental health outcomes,while mediation analysis was conducted to assess the roles of academic stress and interpersonal relationships.Results:1.Defeat is identified as a significant risk factor for mental health issues among college students;2.Four distinct patterns of interpersonal relationships were identified:the interpersonal-relationship risk group,the father–child-relationship high-risk group,the general interpersonal-relationship group,and the superior interpersonal-relationship group;3.Academic stress partially mediates the relationship between defeat and mental health issues such as depression,self-injury,and suicidal ideation;4.Different interpersonal relationship models moderate the impact of academic stress on depression and suicidal ideation.Conclusion:Defeat is a significant risk factor for mental health problems in college students.Academic stress partially mediates the negative impact of defeat on mental health,while patterns of interpersonal relationships moderate this impact.Effective early prevention and intervention should focus on monitoring students’stress levels and fostering warm,positive parent–child relationships.

The Strange Relationship between the Momentum of a Photon Emitted from an Electron and the Momentum Acquired by the Electron

In quantum mechanics, the energy of a hydrogen atom is minimized when the principal quantum number n is 1. However, the author has previously pointed out that the hydrogen atom has a state where n=0. An electron in the state where n=0has zero rest mass energy. However, a hydrogen atom has an energy level even lower than the n=0state. This is hard to accept from the standpoint of common sense. Thus, the author has previously pointed out that an electron at the energy level where n=0has zero energy because the positive energy mec2and negative energy −mec2cancel each other out. This paper elucidates the strange relationship between the momentum of a photon emitted when a hydrogen atom is formed by an electron with such characteristics, and the momentum acquired by the electron.

Research on the strain gauge mounting scheme of track wheel force measurement system based on high-speed wheel/rail relationship test rig

Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system.

Research on the Evaluation System of Community Daycare Center Planning and Implementation from the Perspective of Subject-Object Relationships

Through literature review,we found that evaluations of urban planning implementation often focus narrowly on either the subject(stakeholders)or the object(projects),while micro-level aspects such as site selection and construction are primarily considered within the context of planning implementation.There is insufficient research on the evaluation of implementation.Community daycare centers play a crucial role in the community home care model,yet there is relatively little research on their usage efficiency,satisfaction levels,and spatial evaluation of planning implementation.Based on the theoretical understanding of the human environment,including the subject,object,and their interactions,an evaluation system for the planning and implementation of community day care centers was constructed,incorporating subjective evaluation,objective evaluation,and comparative analysis.

Nonlinear Relationship and Its Evolutionary Trace between Node Degree and Average Path Length of China Aviation Network Based on Complex Network

In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the node average path length of China aviation network in 1988,1994,2001,2008 and 2015 was calculated.Through regression analysis,it was found that the node degree had a logarithmic relationship with the average length of node path,and the two parameters of the logarithmic relationship had linear evolutionary trace.Key word:China aviation network,complex network,node degree,average length of node path,logarithmic relationship,evolutionary trace.

Nonlinear Relationship and Its Evolutionary Trace between Average Degree and Average Path Length of Edge Vertices of China Aviation Network Based on Complex Network

In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the average degree and the average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the average degree and average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 were calculated.Through regression analysis,it was found that the average degree had a logarithmic relationship with the average path length of edge vertices and the two parameters of the logarithmic relationship had linear evolutionary trace.

Phylogenetic Relationships and Status Quo of Colonies for Gayal Based on Analysis of Cytochrome b Gene Partial Sequences

Thirty-three mutations and four different haplotypes were found when cytochrome b（Cytb） gene partial sequences of 12 gayals were analyzed. Together with sequences of Bos indicus, Bos taurus, Bos grunniens, and Bos gaurus with Bubalus bubalis as the out group, the partial sequences of Cytb gene of gayals were aligned and base composition and nucleotide variation of Cytb gene were analyzed. The phylogenetic trees were constructed by the NJ method and the MP method respectively, both supporting almost the same topology. Gayal is an independent species of Bos from Bos indicus, Bos taurus, and Bos gaurus. The results also indicate that a great proportion of gayal bloodline was invaded by other species, and the protection of gayal is facing a formidable situation.

Genetic Relationships Among Four Minorities in Guangxi Revealed by Analysis of 15 STRs

The aim of this study is to investigate the genetic diversity in 15 STRs （short tandem repeats） loci of four minorities in Guangxi Province and to probe into the genetic variation and relationships among these ethnic groups. Allele frequencies of 15 STR loci were collected from 766 unrelated Mulao, Maonan, Miao, and Yao ethnic individuals by PCR-STR and sequencing, and their allele-frequency distribution were compared with each other. The genetic parameters and genetic distances were calculated, and the phylogenetic tree was constructed. Based on the results from this study, 135, 134, 148, and 145 alleles and 424, 432, 445, and 436 genotypes for 15 STR loci were observed in the Mulao, Maonan, Miao, and Yao minorities, respectively. The average heterozygosity of all ethnic groups analyzed was above 0.7; the cumulative power of discrimination （DP）, the probabilities of paternity exclusion （EPP）, and the polymorphic information content （PIC） were greater than 0.99999. Comparison of the allele-frequency distribution indicated that there were significant differences at most loci between Maonan vs. Miao, Yao vs. other groups, but no distinct differences between Mulao vs. Maonan, and Mulao vs. Miao minorities. The NJ tree based on the genetic distance showed that the four minorities were separated into two groups. Mulao and Maonan were clustered into one group, whereas Miao and Yao into the other. Our results revealed that 15 STR loci of the four minorities possessed high genetic diversities. Therefore, the combination of these 15 STRs is a powerful tool for forensic individual identification and paternity investigation, as well as anthropologic and genetic researches. The genetic variation and relationships among the 4 populations revealed by 15 STRs are basically consistent with their linguistic culture and ethical history.

The Phylogenetic Relationships among Four Subspecies of the Genus Locusta Based on Sequences of Three Subunit of Cytochrome Oxidase

[Objective] The aim was to explore the phylogenetic relationships among four subspecies of the genus Locusta.[Method] The sequences of three subunits of cytochrome oxidase of Locusta migratoria tibetensis and Locusta migratoria manilensis were amplified and sequenced（COⅠ 1 539 bp,COⅡ 684 bp,CO Ⅲ 792 bp,with the total of 3 015 bp）.The corresponding sequenses of Locusta migratoria migratoria and Locusta migratoria migratorioides were obtained from GenBank and constructed a multiple alignment.Phylogenic trees of four subspecies of L.migratoria were constructed by Neighbor-Joining,Maximum-parsimony and Bayesian,respectively.[Result] The average content of A ＋ T in three subunits of four subspecies was 69.57%;the third site of codon showed the highest A ＋ T content,and the COⅠ had the highest A ＋ T content（87.6%）;The nucleotide substitution mainly occurred at the third site of codon,and the nucleotide replacement rate of CO Ⅱ was the highest.The second site of codon was conservative,so the replacement rate was in the range of 5.9%-15%.The start codon of COⅠ was CCG or ACG.Genetic distances among four subspecies were ranged from 0.001 to 0.076.The relationship between L.m.tibetensis and Locusta migratoria manilensis was the closest,followed by L.m.migratorioides and L.m.migratorioides,while the genetic distance between L.m.tibetensis and L.m.migratorioides was the largest.[Conclusion] The phylogenetic relationships among four subspecies of Locusta migratoria is L.m.tibetensis,L.m.manilensis,L.m.migratoria,L.m.migratorioides.

Genetic relationship of interspecies for eight birch species

Genetic relationships of eight species of genus Betula were evaluated using ISSR marks. A total of 236 loci were generated from 17 ISSR primers. Percentage of polymorphic bands (PPB) varied from 5.93 to 19.92. The highest and the lowest level of genetic differentiation were detected in B. ovalifolia and B. maximowicziana Regel respectively. In these eight species, genetic diversity of birch (HT) was 24.38 %, and the genetic variation (GST ) interspecies was accounting for 79.36% of total genetic variation. According to the cluster results of genetic distance, the eight species were classified into three groups as B. davurica, B. ovalifolia, B. platyphylla and B. pendula for one group; B. schmidtii, B. costata and B. ermanii Cham. var. communis for one group, and B. maximowicziana Regel for another group. The result of cluster is consistent with traditional morphological classification.

Application of PCA and HCA to the Structure-Activity Relationship Study of Fluoroquinolones

Density functional theory （DFT） was used to calculate molecular descriptors （properties） for 12 fluoro-quinolone with anti-S.pneumoniae activity. Principal component analysis （PCA） and hierarchical cluster analysis （HCA） were employed to reduce dimensionality and investigate in which variables should be more effective for classifying fluoroquinolones according to their degree of an-S.pneumoniae activity. The PCA results showed that the variables ELUMO, Q3, Q5, QA, logP, MR, VOL and △EHL of these compounds were responsible for the anti-S.pneumoniae activity. The HCA results were similar to those obtained with PCA.The methodologies of PCA and HCA provide a reliable rule for classifying new fluoroquinolones with antiS.pneumoniae activity. By using the chemometric results, 6 synthetic compounds were analyzed through the PCA and HCA and two of them are proposed as active molecules with anti-S.pneumoniae, which is consistent with the results of clinic experiments.

Assessment of Genetic Variability and Inter-specific Relationships among Four Species of Groupers (Genus Epinephelus) from South China Sea Using Microsatellite Markers

[Objective] The study aimed to evaluate the genetic variability and interspecific relationships among four species of groupers from South China Sea, including E. fario, E. merra, E. malabaricus and E. coioides. [Method] Twenty one mircosatellite loci of groupers were selected from GenBank and eight high polymorphic loci were used to further genetic analysis. [Result] The mean number of alleles per locus （A）, effective number of alleles （Ne）, mean polymorphism information content （PIC）, observed heterozygosity （Ho） and expected heterozygosity （He） were 4.38±1.60, 3.69±0.86, 0.69±0.08, 0.67±0.08, 0.72±0.06 in E. malabaricus; 3.88±1.13, 3.55±1.04, 0.66±0.10, 0.68±0.21, 0.70±0.08 in E.coioides; 6.00±1.07, 4.68±0.65, 0.78±0.03, 0.73±0.25, 0.79±0.03 in E. fario; 5.50±1.07, 4.58±0.80, 0.76±0.05, 0.75±0.18, 0.78±0.04 in E. merra, respectively. [Conclusion] We compared the values above, the order of the genetic variability among these grouper species was E. fario E. merra E. malabaricus E. coioides. We found that the level of genetic variability of these groupers species was relatively higher than that of other marine fish, so their genetic status was good. In addition, the analyisis of genetic relationship showed that E. malabaricus and E. coioides was the closest and it was the farthest between E. merra and E. coioides.

Phylogenetic Relationships of Caragana(Fabaceae) by the Use of nrITS Sequences

[Objective] The aim was to explore the phylogenetic relationships of Cara- gana （Fabaceae） by the use of nrlTS sequences. [Method] Internal transcribed spac- er （ITS） sequences of nuclear ribosomal DNA （nrDNA） from 29 taxa of Caragana species and seven close relatives （all belong to Astralinae （Adens） Benth） were used for phylogenetic analysis. [Result] Length of the entire ITS region ranges from 611 to 614 bp in Caragana species. The aligned sequences nrlTS of Caragana are 655 bp, and 170 sites are variable, with 107 phylogenetically informative sites. The phylogenetically informative sites are 16.3% of the total aligned sequences. The ITS sequences data are useful to resolve some relationships at lower taxonomic levels within Caragana. The Caragana Fabr. is not a monophyletic group with very close connection with Calophaca tianschanica. The ITS data revealed that the species of Sect. tragacanthoides were dispersed in MP tree or ME tree. Although the morphol- ogy of C. ordosica is similar to C. tibetica, the ITS results revealed an unexpectedly close relativeship to C. roborovskyi. The ITS data also indicate C. davazamcii, C. korshinskii, C. intermedia, and C. microphylla are different species. [Conclusion] ITS sequences have an important reference value in exploring the relationships of Cara- gana.

ISSR Analysis of Genetic Relationship of Germplasm Resource in Prunus mume Sibe. et Zucc

Using ISSR technique to analyze the diversity and genetic relationship of germplasm resources in 39 Prunus mume Sibe. et Zucc., the result showed that 10 primers were screened with high resolution from 51 primers, 120 fragments were amplified, of which 98 were polymorphic loci, accounting for 81.67% of total. Tested materials were divided into 3 classes, as was fundamentally accorded with the traditional classification base on horticulture. There was no obvious difference in geographic relationship among the clustering results.