Effects of Planting Density, Duration of Disclosing Plastic Film and Nitrogen Fertilization on the Growth Dynamics of Rapeseed under No-tillage Cultivation

[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be： planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.

The Influence of Fluctuated Soil Moisture on Growth Dynamic of Winter Wheat

Glasshouse and laboratory tests were carried out in 1996 - 1998 using winter wheat cultivars Beinong 6 as materials. The growth dynamics of the whole-wheat plant were analysed under constant and fluctuated soil water condition. The results revealed that water stress made the starting time of crop greatest growth phase(STCGGP) in advance, prolonged crop greatest growth phase(CGGP), decreased the rate of crop greatest growth (CGGR or CGRm), and as a result, the rate of dry matter accumulation was reduced and the growth of the crop was slowed down. Rewatering delayed STCGGP, shortened CGGP, increased CGGR, thus, the rate of dry matter accumulation had been boosted and the growth of the crop was accelerated. The growth rate, dry matter weight and grains yield of winter wheat were almost equal to the well-watered controls if they were rewatered under the condition of moderate water stress during the jointing stage.

Growth Dynamics and Optimal Harvesting Stage of Two Forage Maize Varieties

SAUMZ 1 and SAUMZ 2 are two forage maize varieties reproduced by distant hybridization.In a randomized block experiment,their fresh forage yield and dry matter yield were investigated on the basis of growth period,leaf stage,and effective accumulated temperature.The nutritional components were measured in a near infrared diffuse reflectance spectroscopy.Referring to the concept of forage grading index,a formula was constructed to calculate the total digestible energy.The investigated characters and indexes were adapted to suitable models of growth dynamics.The results showed that these two varieties have strong heterosis in fresh forage yield,dry matter yield,and total digestible energy.Their growth dynamics were adapted to Logistic models described by general equation y=k/（1＋ae-bx）.The forage grading indexes of these two varieties were decreased linearly along with the increasing of their leaf stage.The stopping point of fast growing period of total digestible energy estimated on the basis of leaf stage was suggested to be used as optimal harvesting stage of forage maize.The optimal harvesting stage was estimated to be tasseling stage for SAUMZ 1 and 19.50-leaf stage for SAUMZ 2.

Radial growth in Qinghai spruce is most sensitive to severe drought in the Qilian Mountains of Northwest China

Global warming and frequent extreme drought events lead to tree death and extensive forest decline,but the underlying mechanism is not clear.In drought years,cambial development is more sensitive to climate change,but in different phenological stages,the response rela-tionship is nonlinear.Therefore,the dynamic relationship between tree radial growth and climatic/environmental fac-tors needs to be studied.We thus continuously monitored radial growth of Qinghai spruce(Picea crassifolia Kom.)and environmental factors from January 2021 to November 2022 using point dendrometers and portable meteorological weather stations in the central area of the Qilian Mountains.The relationship and stability between the radial growth of Qinghai spruce and environmental factors were compared for different levels of drought in 2021 and 2022.The year 2022 had higher temperatures and less precipitation and was drier than 2021.Compared with 2021,the growing period in 2022 for Qinghai spruce was 10 days shorter,maximum growth rate(Grmax)was 4.5μm·d^(-1) slower,and the initiation of growth was 6 days later.Growth of Qinghai spruce was always restricted by drought,and the stem radial increment(SRI)was more sensitive to precipitation and air relative humidity.Seasonal changes in cumulative radial growth were divided into four phenological stages according to the time of growth onset,cessation,and maximum growth rate(Grmax)of Qinghai spruce.Stability responses of SRI to climate change were stronger in Stage 3 and Stage 4 of 2021 and stronger in Stage 1(initiation growth stage)and Stage 3 of 2022.The results provide important information on the growth of the trees in response to drought and for specific managing forests as the climate warms.

Molecular dynamics study of anisotropic growth of silicon

Based on the Tersoff potential, molecular dynamics simulations have been performed to investigate the kinetic coefficients and growth velocities of Si（100）,（110）,（111）, and（112） planes. The sequences of the kinetic coefficients and growth velocities are μ（（100））〉 μ（（110））〉 μ（（112））〉 μ（（111））and v（（100））〉 v（（110））〉 v（（112））〉 v（（111））, respectively, which are not consistent with the sequences of the interface energies, interplanar spacings, and melting points of the four planes. However,they agree well with the sequences of the distributions and diffusion coefficients of the melting atoms near the solid–liquid interfaces. It indicates that the atomic distributions and diffusion coefficients affected by the crystal orientations determine the anisotropic growth of silicon. The formation of stacking fault structure will further decrease the growth velocity of the Si（111） plane.

DYNAMICAL FORMATION OF CAVITY FOR COMPOSED THERMAL HYPERELASTIC SPHERES IN NONUNIFORM TEMPERATURE FIELDS

Dynamical formation and growth of compressible thermal-hyperelastic Gent-Thomas cavity in a sphere composed of two inmaterials were discussed under the case of a non-uniform temperature field and the surface dead loading. The mathematical model was first presented based on the dynamical theory of finite deformations. An exact differential relation between the void radius and surface load was obtained by using the variable transformation method. By numerical computation, critical loads and cavitation growth curves were obtained for different temperatures. The influence of the temperature and material parameters of the composed sphere on the void formation and growth was considered and compared with those for static analysis. The results show that the cavity occurs stiddenly with a finite radius and its evolvement with time displays a non-linear periodic vibration and that the critical load decreases with the increase of temperature and also the dynamical critical load is lower than the static critical load under the same conditions.

Simulation Study on the Alkalized-salinized Grassland Ecosystem in the Songnen Plain

Using Object-oriented design and a new programming language JAVA, a physically-based model was built to simulate the hydrological, alkalization/de-alkalization and salinization/desalinization processes in soil. Furthermore, a process-based model was built to evaluate the dynamics of four herbaceous ecosystems (including dynamics of above-ground biomass, below-ground biomass, and litter biomass), each dominated by Aneurolepidium chinense (Trin.) Kitag., Chloris virgata Sw., Puccinellia tenuiflora (Turcz.) Scribn. et Merr. and Suaeda glauca Bunge. This model is a daily-time step model, suitable for simulating hydrological, alkalization/de-alkalization and salinization/desalinization processes of heterogeneous soil, and growth dynamics of different grassland communities. With climatic data and experimental data of Changling Experimental Site in Jilin Province, the soil moisture content (in 1991, 1996, 1997 and 1998), soil salt concentration, exchangeable cation percentage and pH in soil and growth dynamics of these four sorts of grassland communities (in 1991) were simulated and the results were verified to be in accord with observed data.

Growing actin networks regulated by obstacle size and shape

Growing actin networks provide the driving force for the motility of cells and intracellular pathogens. Based on the molecular-level processes of actin polymerization, branching, capping, and depolymerization, we have developed a modeling framework to simulate the stochastic and cooperative behaviors of growing actin networks in propelling obstacles, with an emphasis on the size and shape effects on work capacity and filament orientation in the growing process. Our results show that the characteristic size of obstacles changes the protrusion power per unit length, without influencing the orientation distribution of actin filaments in growing networks. In contrast, the geometry of obstacles has a profound effect on filament patterning, which influences the orientation of filaments differently when the drag coefficient of environment is small, intermediate, or large. We also discuss the role of various parameters, such as the aspect ratio of obstacles, branching rate, and capping rate, in affecting the protrusion power of network growth.

Dynamic observation of in-plane h-BN/graphene heterostructures growth on Ni(lll)

The lateraI incorporation of graphene and hexagonal boron nitride(h-BN)onto a substrate surface creates irvplane h-BN/graphene heterostructures,which have promising applications in novel two-dimensional electronic and photoelectronic devices.The quality of h-BN/graphene domain boundaries depends on their orientation,which is crucial for device performances.Here,the heteroepitaxial growth of graphene along the edges of h-BN domains on Ni(111)surfaces as well as the growth dynamics of h-BN using chemical vapor deposit!on(CVD)are in situ investigated by surface imaging measurements.The nucieating seed effect of h-BN has been revealed,which con tributes to the single orie ntation of heterostructures with epitaxial stitch i ng.Further,the growth of h-BN prior to that of graphene is essential to obtain high-quality in-plane h-BN/graphene heterostructures on Ni(111).The“compact to fractal”shape transition of h-BN domains appears with the increasing surface concentration of the growth blocks,suggesting that the dynamic growth mechanism follows diffusion-limited aggregation(DLA)but not reaction・limited aggregation(RLA).Our results provide in sights into the syn thesis of well-defi ned h-BN/graphene heterostructures and deep un derstanding of the growth dynamics of h-BN on metal surfaces.

Genetic Effect Analysis of Quantitative Traits and Selection of Excellent Population in Betula platyphylla var.mandshurica Hara.

Betula platyphylla var. mandshurica Hara. is a geographical variant of B. platyphylla Suk. with strong adaptability, rapid growth, fine texture, wide application and other notable features. In order to investigate the genetic effects of quantitative traits and specificity of different populations of B. platyphylla var. mandshurica Hara. , by permanent sample plot continuous measurement and temporary sample plot random investigation, B. platyphyUa var. mandshurica Hara. populations naturally distributed in Zhangguangcailing Mountain and Laoye Mountain in Changbai Mountain Range were used as experimental materials to systemati- cally analyze the growth dynamic patterns of plant height and diameter at breast height, and comprehensively evaluate the genetic effects of various quantitative traits. According to the results, site conditions suitable for B. platyphylla var. mandshurica Hara. were classified into four grades according to the absolute value of partial correlation coefficients. The growth process of B. platyphylla var. mandshurica Hara. stand generally underwent rapid growth period, steady growth period and slow growth period. The growth of B. platyphylla var. mandshurica Hara. stand at different growth stages varied signitlcantly among various site grades, but the growth trend was basieally the same. Plant height, diameter at breast height, east-west crown diameter and north-south crown diameter varied significantly among B. platyphylla vat. mandshurica Hara. populations, exhibiting extremely significant differences. The heritability of four growth traits was 0. 558,0. 762, 0. 652 and 0. 722, respectively; the genetic gain was 8.09%, 17.67%, 14.56% and 17.53%, respectively. Based on comprehensive evaluation of various indicators, MES （Maoershan） was identified as an excellent population, which exhibited minor variations between individuals within the population, stable growth, strong growth potential and remarkable genetie effects.

STUDY ON COMMUNITY STRUCTURE AND SELF-SUSTAINING MECHANISM OF BROAD-LEAVED/KOREAN PINE FORESTS IN NORTHEAST CHINA

The regeneration, tree growth, and community structure and dynamics were studied in old-growth Korean pine (Pinus koraiensis) forest.The results showed that the formation of tree form and growth character have been obviously related with the gap-phase regeneration.The ecological effects of the gap suppress the tree growth in diameter,and control that young tree stem fork in early stage.The heterogeneity of tree growth in time and space is the results of high quality in tree height and diameter.The hardwood species mixth Korean pine have different ecological effect on regeneration and tree growth of Korean pine in the early stage of gap reconstructing. Community dynamics depends on tree gaps oceurs,in which a 'cyclic sucession'between Korean pine and hard wood species may occurs.The process would take about 200 yers.

Impact of Wavelength-Routed Network Physical Topology on Blocking Probability Using a Dynamic Traffic Growth Model

We investigate the impact of network topology on blocking probability in wavelength-routed networks using a dynamic traffic growth model. The dependence of blocking on different physical parameters is assessed.

Investigation on Occurrence of Lithocolletis ringoniella Adults in New and Aged Apple Orchards in Shijiazhuang Area

[Objective]The paper was to investigate the occurrence of Lithocolletis ringoniella adults in aged and new apple orchards in Shijiazhuang area.[Method]The growth and decline dynamics of L.ringoniella adults in 3a apple orchard and 17a apple orchard in Shijiazhuang were monitored by sex attractant trapping method.Meantime,the trapping effects of sex attractant on L.ringoniella were compared with that of sweet-sour liquor.[Result]L.ringoniella occurred five generations annually in Shijiazhuang area.The adults emerged in April,and entered into peak occurrence period during May and June,with overlapping generations.Comparison between sex attractant and sweet-sour liquor tests showed that the trapping effect of sweet-sour liquor received little effect,but was expensive.Therefore,it is not recommended to use sweet-sour liquor for prevention and treatment of L.ringoniella in production.[Conclusion]In the actual production,sex attractant trapping should be combined with appropriate agricultural control measures to control the damage of L.ringoniella.

Effective shape-controlled synthesis of gallium selenide nanosheets by vapor phase deposition

The controlled synthesis of large and uniform gallium selenide(GaSe)crystals is crucial for its various applications based on the attractive properties of this emerging material.In this work,vapor phase growth of high-quality monolayer GaSe nanosheets with multiple shape and size is achieved by tuning the Ga/GaSe ratio in the precursor.A theoretical model based on density functional theory calculations and kinetic Wulff construction theory describe the observed shape evolution of the GaSe nanosheets.Results show that the Ga/Se ratio plays a critical role in the evolution of the domain shape and size.Moreover,the as-grown GaSe nanosheets show improved performance with photoresponse time less than 0.7 ms and responsibility up to 3,000 AW.This study presents a previously unexplored strategy for the controlled growth of two-dimensional(2D)GaSe nanosheets for promising applications in next-generation optoelectronics.

Impact of Climate Change on Maize Potential Productivity and the Potential Productivity Gap in Southwest China

The impact of climate change on maize potential productivity and the potential productivity gap in Southwest China（SWC） are investigated in this paper.We analyze the impact of climate change on the photosynthetic,light-temperature,and climatic potential productivity of maize and their gaps in SWC,by using a crop growth dynamics statistical method.During the maize growing season from 1961 to 2010,minimum temperature increased by 0.20℃ per decade（p 〈 0.01） across SWC.The largest increases in average and minimum temperatures were observed mostly in areas of Yunnan Province.Growing season average sunshine hours decreased by 0.2 h day^（-1） per decade（p 〈 0.01） and total precipitation showed an insignificant decreasing trend across SWC.Photosynthetic potential productivity decreased by 298 kg ha^（-1）per decade（p 〈 0.05）.Both light-temperature and climatic potential productivity decreased（p 〈 0.05） in the northeast of SWC,whereas they increased（p 〈 0.05） in the southwest of SWC.The gap between lighttemperature and climatic potential productivity varied from 12 to 2729 kg ha^（-1）,with the high value areas centered in northern and southwestern SWC.Climatic productivity of these areas reached only 10%-24%of the light-temperature potential productivity,suggesting that there is great potential to increase the maize potential yield by improving water management in these areas.In particular,the gap has become larger in the most recent 10 years.Sensitivity analysis shows that the climatic potential productivity of maize is most sensitive to changes in temperature in SWC.The findings of this study are helpful for quantification of irrigation water requirements so as to achieve maximum yield potentials in SWC.

High-strain-rate superplasticity in oxide ceramics:a trial of microstructural design based on creep-cavitation mechanisms

From existing knowledge about high-temperature cavitation mechanisms, necessary conditions were discussed for the suppression of cavitation failure during superplastic deformation in ceramic materials. The discussion, where special attention was placed on the relaxation of stress concentrations during grain-boundary sliding and cavity nucleation and growth, leaded to a conclusion that cavitation failure could be retarded by the simultaneous controlling of the initial grain size, the number of residual defects, diffusivity, dynamic grain growth and the homogeneity of microstructure. On the basis of this conclusion, high-strain-rate superplasticity （defined as superplasticity at a strain rate higher than 0.01 s^-1） could be intentionally attained in some oxide ceramic materials. This was shown in tetragonal zirconia and composites consisting of zirconia, a-alumina and a spinel phase.