一类拟树的Euler子图

介绍了一类拟树所包含的Euler子图的个数,给出了简洁的计算公式,并进行了严格、详尽的证明.有关结果在理论物理的某些研究中具有重要的理论与应用价值.

拟树的广义零阶连通指数

设G=(V,E)是一个图,参数Mα(G)=∑υ∈V(d(υ))α称为G的广义零阶连通指数,其中d(υ)表示G中顶点υ的度,α为任意实数.若图G中有一个顶点x,使得G-x是一棵树,则称G为拟树(quasi-tree).对于α>1,该文给出了顶点数为n的拟树G的广义零阶连通指数Mα(G)的精确上界和下界.

拟树的Wiener指数

给出了n阶非平凡拟树Wiener指数的上下界,并给出了极大图,刻画了极小图的性质.

具有最大无符号拉普拉斯谱半径的拟树

若存在一个顶点,使得删除这个点后得到的图是一个树,则称该图是拟树,该文基于拟树的概念,利用相应的枝节变换,刻画了固定某个顶点的度及给定悬挂点数的所有拟树中具有最大无符号拉普拉斯谱半径的极图.

可分拟满Steiner树的结构性质与最优生成算法的研究

研究可分拟满Steiner树的结构性质与最优可分拟满Steiner树的生成算法.

采自广州的六个拟茎点霉新种(英文)

报告了采自广州的六个拟茎点霉Phomopsis新种:金合欢生拟茎点霉Phomopsis acacicola、叶子花生拟茎点霉Phomopsis bougainvilleicola、樟生拟茎点霉Phomopsis cinnamomicola、八宝树拟茎点霉Phomopsis duabangae、杜鹃拟茎点霉Phomopsis rhododendri和黄花夹竹桃拟茎点霉Phomopsis thevetiae。新种附有拉丁文、英文描述和显微结构图。模式标本保存于华南农业大学真菌标本室(SCHM)。

云南大围山自然保护区的丝孢菌(Ⅲ)

报道云南大围山自然保护区6种丝孢菌,其中云南假绒落菌Pseudospiropesyunnanensis为新种;拟树生霉属Dendryphiopsis,小鼻枝霉属Rhinocladiella为中国新记录属;扫状瓶霉Phialophorafastigiata,杆状钉孢霉Passalorabacilligera,刺绒落菌Spiropesechidnois为中国新记录种。新种提供拉丁文和中文描述及形态图。研究标本收藏于云南农业大学真菌标本室(MHYAU)。

不同杉木无性系材种结构的差异分析

为筛选出适用于定向培育大、中径材的优良无性系,为杉木人工林高效培育精准提供造林材料,选择漳平五一国有林场17年生杉木测定林的39个无性系为研究对象,研究其出材量及材种结构的差异性规律。在野外测定不同杉木无性系胸径与树高的基础上,对树高生长进行拟合,采用最优拟合模型统计各无性系单位面积蓄积量,对实测树高、胸径与单位面积出材量、材种结构材积进行了比较分析。结果表明,不同杉木无性系材种结构差异明显,蓄积量与出材量的差异极显著(P<0.01),出材率受出材量影响显著;选育时可通过对出材量进行聚类及生长量多重对比筛选出符合大、中径材经营的无性系。不同杉木无性系树高拟合模型为H_(i)=2.1979 D_(i)0.6485,在该试验立地条件下,适合大径材培育的7个无性系为M5、M8、M17、M34、M35、M43、M50,其生长量差异不明显,大径材出材量平均值为153.83 m^(3)·hm^(-2),大径材出材率平均值为40.52%;适合中径材培育的无性系为M1、M11、M13、M16、M23、M33、M37,中径材出材量平均值为168.45 m^(3)·hm^(-2),其出材率平均值为55.08%。

逆一般中心选址问题的算法研究

主要讨论了逆一般中心选址问题的算法研究。对于实例是树且U为整数的情况,逆一般中心选址问题转化为逆中心选址问题。对于实例是一般简单图的情况,本文给出了一个逆一般中心选址问题转化为权重为1的S te iner树问题的拟多项式算法。并对于权w=1的S te iner树问题,本文也给出了一个近似界为43的近似算法。

One new species of the genus Uenostrongylium(Coleoptera:Tenebrionidae) from China

One new species,Uenostrongylium scaber Yuan Ren sp.nov.(China,Zhejiang),is described.Habitus and illustrations are provided,and a key to the genus Uenostrongylium is also given.

Fixed-bed column study for deep removal of copper(Ⅱ) from simulated cobalt electrolyte using polystyrene-supported 2-aminomethylpyridine chelating resin

This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height (7.0–14.0 cm),feed flow rate (4.5–9.0 mL/min),initial copper (Ⅱ) concentration of the feed (250–1000 mg/L),feed temperature (25–40 ℃) and the value of pH (2.0–4.0) on the adsorption process of the PS-AMP resin were investigated.The experimental data showed that the PS-AMP resin can deeply eliminate copper (Ⅱ) from the simulated cobalt electrolyte.The bed height,feed flow rate,initial copper (Ⅱ) concentration of the feed,feed temperature and feed pH value which corresponded to the highest removal of copper (Ⅱ) were 7.0 cm with 35 mm of the column diameter,4.5 mL/min,40℃,1000 mg/L and 4.0,respectively.The breakthrough capacity,the saturated capacity of the column and the mass ratio of Cu/Co (g/g) in the saturated resin were correspondingly 16.51 mg/g dry resin,61.72 mg/g dry resin and 37.67 under the optimal experimental conditions.The copper (Ⅱ) breakthrough curves were fitted by the empirical models of Thomas,Yoon-Nelson and Adam-Bohart,respectively.The Thomas model was found to be the most suitable one for predicting how the concentration of copper (Ⅱ) in the effluent changes with the adsorption time.

A new species of the genus Uenostrongylium Masumoto(Coleoptera:Tenebrionidae)from Guangdong,China

A new species,Uenostrongylium gaoi Lin&Yuan sp.nov.from Guangdong,China,is described.It resembles Uenostrongylium scaber Yuan&Ren,2018 from Zhejiang due to the granulated upper edge of elytral punctures.Habitus and illustrations are provided.

Simulation of Cefoselis hydrochloride adsorption on macroporous resin in a fixed-bed column using orthogonal collocation

Adsorption operation is of great importance for separation and purification of semi-synthetic cephalosporin compounds in pharmaceutical industry. The adsorption dynamics of Cefoselis hydrochloride(CFH) on XR 920 C adsorbent in fixed bed was predicted by the model of modified film-pore diffusion(MFPD). The intraparticle diffusion equation and mass balance equation in fixed bed are discretized into two ordinary differential equations(ODEs) using the method of orthogonal collocation which largely improves the calculation accuracy. The MFPD model parameters including the pore diffusion coefficient(Dp), external mass-transfer coefficient(kf), and the axial dispersion(DL) were estimated. The kfvalue was calculated by the Carberry equation, in which the effective diffusion coefficient Dewas fitted based on Crank Model through experimental data. Moreover, three key operating parameters(i.e., initial adsorbate concentration; flow rate of import feed, and bed height of adsorbent) and the corresponded breakthrough curves were systematically studied and optimized. Therefore,this research not only provides valuable experimental data, but also a successfully mathematical model for designing the continuous chromatographic adsorption process of CFH.

Groundwater Flow Model in the Mangrove Forest

The ability to predict groundwater fluxes with a minimum of effort and measurement is an important objective. Numerical modeling is one approach to obtain such a prediction. Predictions of groundwater fluxes can be used to determine fluxes of other materials such as salt and nutrients. In this paper an analytical model is developed to predict the flow of groundwater from mangrove forest to the creek. The model uses the geometry and hydraulic conductivity of the mangrove forest sediment, which is inundated by tidal water from day zero to day five, with the flux ranged from 0.026 to 0.007 m^3/（m^2.day） with the average error is about 10%. The solution for the groundwater flow is written in terms of an analytic series solution, based on two dimensional potential flow. The approach is basically to solve the hydraulic potential flow for steady state conditions using the Laplace equation. The advantages of this method are that it is simple but accurate, and the error in the computation can be readily calculated. The result of this model is then compared to the result of the field measurement from also day zero to day five after inundation, which ranged from 0.030 to 0.013 m3/（m2.day） with the average error is about 40%. From the above results, it is concluded that the series solution model can be used to calculate the flux of the groundwater, especially in the mangrove forest area.

Fractal Characteristics of the Distribution Pattern of Mangrove Bruguiera Gymnorrhiza Populations in Southern China

The distribution patterns of mangrove Bruguiera gymnorrhiza population s in southern China are analyzed using the box-counting method of fractal theory. The patterns of B. gymnorrhiza populations could be thought of as fractals as they exhibit self-similarity within the range of scale considered. Their fractal dimensions are not integer but fractional, ranging from 1.04 to 1.51. The unoccupied dimensions change from 0.49 to 0.96. The combined conditions of population density, pattern type and aggregation intensity together influence the values of fractal dimensions of patterns. The box counting is a useful and efficient method to investigate the complexity of patterns. Fractal dimension may be a most desirable and appropriate index for quantifying the horizontal spatial microstructure and fractal behaviors of patterns over a certain range of scales.

Simulation of Curing Process for Propargyl Terminated Novolac Resins

Non-isothermal kinetic simulation analysis was carried for CFRP （carbon fiber reinforced plastic） based on PN （propargylated novolac） resins with various curing enthalpy. The simulation study was performed for CFRP with 40% mass resin content. It was shown that, curing enthalpy of PN resin must be less than 600 J/g to avoid uncontrolled heat emission causing destruction of composite sample.

In silico prediction of phytoconstituents from Ehretia laevis targeting TNF-αin arthritis

Objective Rheumatoid arthritis(RA)is an autoimmune disease involving the synovial lining of the major joints.Current therapies have noteworthy side effects.Our study involved in silico evaluation of Ehretia laevis(E.laevis)phytoconstituents targeting tumor necrosis factor-α(TNF-α).Methods Molecular docking studies performed to investigate the binding pattern of the plant E.laevis phytoconstituents along with the crystal structure of TNF-α(PDB ID:2 AZ5)using AutoDock Vina followed by a study of interacting amino acid residues and their influence on the inhibitory potentials of the active constituents.Further the pharmacokinetic profile and toxicity screening carried out using Swiss ADME and pk CSM.Results The docked results suggest that lupeol(-9.4 kcal/mol)andα-amyrin(-9.4 kcal/mol)has best affinity towards TNF-αcompared to standard drug thalidomide(-7.4 kcal/mol).The active chemical constituents represents better interaction with the conserved catalytic residues,leading to the inhibition/blockade of the TNF-α-associated signaling pathway in RA.Furthermore,pharmacokinetics and toxicity parameters of these phytochemicals were within acceptable limits according to ADMET studies.Conclusion The binding potential of phytoconstituents targeting TNF-αshowed promising results.Nonetheless,it encourages the traditional use of E.laevis and provides vital information on drug development and clinical treatment.

A Molecular Dynamic Modelling of Cross-Linked Epoxy Resin Using Reactive Force Field： Thermo-Mechanical Properties

The reactive force field was used to study the molecular dynamics of cross-linked EPON 862 （diglycidyl ether of bisphenol-F） and DETDA （diethylene toluene diamine） system in order to predict its thermo-mechanical behavior under different loading conditions. The approach for building the EPON 862/DETDA structures, cross-linking, and equilibration of the systems, and the evaluation of the models are presented. The mechanical properties such as Young＇s and shear moduli, Poisson ratio, and yields strength as well as thermal properties such as glass transition temperature and coefficient of thermal expansion are predicted. The results are in close agreement with both experimental data and simulated results in literature.

Coseismic Effect Simulation of Yushu M_S 7.1 Earthquake and Absolute Gravity Inspection

Using the results of aftershock relocation, inversion on seismic waves and InSAR results, and surface rupture displacements obtained by geological survey after the earthquake, this paper constructs a fault model of the Yushu Ms7. 1 earthquake. Based on rectangular dislocation theory in an elastic-viscoelastic layered medium, we have simulated the co- seismic deformation and gravity change with gravitational effect considered. The pictures show that the absolute gravity measuring point is beside the extremum of coseismic gravity change, and the numerical value reaches 25.02 x 10-Sm. s-2. After a discussion about the gravity changes before the earthquake and the coherence consistency between two FG-5 absolute gravimeters, we think that the measured value 27.2 × 10^-8 m· s^-2 at Yushu station is coseismic gravity change. It＇s coincident with the simulation results based on dislocation theory. Therefore it is a good tool to test the near-field changes found by dislocation theory.

Parameterization of height-diameter and crown radius-diameter relationships across the globe

The tree height-diameter at breast height(H-DBH)and crown radius-DBH(CR-DBH)relationships are key for forest carbon/biomass estimation,parameterization in vegetation models and vegetation-atmosphere interactions.Although the H-DBH relationship has been widely investigated on site or regional scales,and a few of studies have involved CR-DBH relationships based on plot-level data,few studies have quantitatively verifed the universality of these two relationships on a global scale.This study evaluated the ability of 29 functions to ft the H-DBH and CR-DBH relationships for six different plant functional types(PFTs)on a global scale,based on a global plant trait database.Results showed that most functions were able to capture the H-DBH relationship for tropical PFTs and boreal needleleaf trees relatively accurately,but slightly less for temperate PFTs and boreal broadleaf trees(BB).For boreal PFTs,the S-shaped Logistic function ftted the H-DBH relationship best,while for temperate PFTs the Chapman-Richards function performed well.For tropical needleleaf trees,the fractional function of DBH satisfactorily captured the H-DBH relationship,while for tropical broadleaf trees,the Weibull function and a composite function of fractions were the best choices.For CR-DBH,the ftting capabilities of all the functions were comparable for all PFTs except BB.The Logistic function performed best for two boreal PFTs and temperate broadleaf trees,but for temperate needleleaf trees and two tropical PFTs,some exponential functions demonstrated higher skill.This work provides valuable information for parameterization improvements in vegetation models and forest feld investigations.