A MATHEMATICAL MODEL OF ENTERPRISE COMPETITIVE ABILITY AND PERFORMANCE THROUGH A PARTICULAR EMDEN-FOWLER EQUATION

In this paper we work with the ordinary diffential equation u′′ u3 = 0 and obtain some interesting phenomena concerning blow-up, blow-up rate, life-spann, zeros and critical points of solutions to this equation.

A MATHEMATICAL MODEL OF ENTERPRISE COMPETITIVE ABILITY AND PERFORMANCE THROUGH EMDEN-FOWLER EQUATION FOR SOME ENTERPRISES

In this paper, we work with the ordinary differential equation n^2u （n）＂ = u（n）^p and obtain some interesting phenomena concerning, boundedness, blow-up, blow-up rate, life-span of solutions to those equations.

Effects of water and nitrogen on growth and relative competitive ability of introduced versus native C_(4)grass species in the semi-arid Loess Plateau of China

Switchgrass is an introduced C_(4)grass in the semi-arid Loess Plateau of China,but there is a lack of information to assess its ecological invasive risk.In this study,Old World bluestems(native C_(4)grass)and switchgrass were sowed at five mixture ratios(8:0,6:2,4:4,2:6 and 0:8)under two soil water levels(80%field capacity(FC)and 40%FC)and two nitrogen(N)treatments(0 and 100 mg N/kg dry soil,termed N0-unfertilized and N1-fertilized treatments,respectively)in a pot experiment in 2012.Biomass,root morphological traits and relative competitive abilities of these two species were analyzed.Results showed that biomass of both species was significantly greater under 80%FC or N fertilization,and switchgrass had a relatively larger root:shoot ratio(RSR).Total root length(TRL)and root surface area(RSA)of switchgrass were significantly higher under 80%FC irrespective of N treatment,while those of Old World bluestems were only significantly higher under N fertilization.N had no significant effect on TRL and RSA of switchgrass,while RSA of Old World bluestems significantly increased under 80%FC and N fertilization.Under 40%FC and N0-unfertilized treatment,the aggressivity of Old World bluestems was larger than zero at 2:6 and 4:4 mixture ratios of two species,whereas it was close to zero at 6:2 mixture ratio.Root competitive ability of switchgrass significantly increased under 80%FC or N fertilization.The aggressivity of Old World bluestems was negative at 6:2 mixture ratio under 80%FC and N fertilization,while it was positive at 2:6 mixture ratio.Switchgrass may become more aggressive when N deposition or rainfall increases,while a proper mixture ratio with appropriate water and N management could help with grassland management in the semi-arid Loess Plateau.

MATHEMATICAL MODEL FOR THE ENTERPRISE COMPETITIVE ABILITY AND PERFORMANCE THROUGH A PARTICULAR EMDEN-FOWLER EQUATION u〞-n^(-q-1)u(n)~q=0

In this article, we work with the ordinary equation u″-n-q-1u（n）q=0 and learn some interesting phenomena concerning the blow-up and the blow-up rate of solution to the equation.

A MATHEMATICAL MODEL OF ENTERPRISE COMPETITIVE ABILITY AND PERFORMANCE THROUGH EMDEN-FOWLER EQUATION (Ⅱ)

In this paper we work with the ordinary equation u＇＇ - u2 （u ＋ ） = 0 and ob- tain some interesting phenomena concerning, blow-up, blow-up rate, life-span of solutions to those equations.

Teaching Design and Implementation of the Electrical and Electronic Technology Course Based on Teaching Ability Competition

The teaching ability competition is a vital method for stimulating teachers’enthusiasm and enhancing their teaching skills.This approach has gained increasing attention from colleges and universities in recent years.The competition focuses on evaluating teachers’capabilities in designing and implementing lessons,encouraging the exchange of new educational ideas and high-quality teaching methods.Reforming the teaching of Electrical and Electronic Technology courses based on insights from teaching competitions can significantly improve teaching quality.This paper explores the teaching design and implementation of the Electrical and Electronic Technology course,drawing on the principles of teaching ability competitions.First,it analyzes the existing problems in teaching this course.Then,it highlights the significant benefits that teaching competitions bring to the course.Based on these insights,the paper proposes practical strategies aimed at enhancing students’interest and practical skills,thereby promoting innovative developments in teaching Electrical and Electronic Technology.

Individual growth, competitive ability and stand-level biomass production of invasive Sorghum halepense populations on Hainan island, China

Aims Sorghum halepense is a perennial invasive weed causing great harm worldwide,including some regions on Hainan island.In this study,we compared the performance between plants from outbreaking(dense stands covering large areas)and those from non-outbreaking(less dense stands covering smaller areas)populations.We also tested the hypothesis that plants with greater intraspecific competitive ability will have a lower stand biomass when grown under high-density conditions.Methods We grew plants of S.halepense individually,with an intraspecific competitor,with two interspecific competitors and with three or six plants from the same population per pot,and tested whether outbreaking and non-outbreaking populations differed in their performance.We also tested whether stand biomass(i.e.total biomass when three or six plants were grown together)was related to total biomass of individuals grown alone,and intra-or interspecific competitive ability.Important Findings Outbreaking and non-outbreaking populations of S.halepense differed in their biomass when individuals were grown alone,but not when grown in competition or when three or six plants from the same population were grown together.Across populations,biomass of individuals grown alone was negatively correlated with intra-and interspecific competitive ability,indicating that there is a trade-off between individual growth and competitive ability.Stand-level biomass was not related to total biomass of individuals grown alone,and intra-or interspecific competitive ability,indicating that low biomass when grown alone and high competitive ability may not reduce the performance of S.halepense when grown in dense monocultural stands.

Relationship between population competitive intensity and yield in maize cultivars

Competition is a common phenomenon in agriculture production.Research on the relationship between competitive ability and crop yield is extensive,but the results have been inconsistent.Few studies have focused on the relationship between population competitive intensity and yield of maize（Zea mays L.）cultivars.The main objective of this study was to determine if a consistent relationship exists between maize yield and competitive ability.A two-year field experiment was conducted,employing a de Wit replacement series design.When two maize cultivars were grown in a mixture,yield was reduced for the modern cultivar and increased for the older cultivar.In each replacement series,per plant level yield of each cultivar,and population level yield of the mixture,decreased with increasing proportion of the older cultivar.Competitive ratio（CR）reflected differences in competitive ability of the three maize cultivars.In each replacement series,population competition pressure（PCP）increased with increasing proportion of the older cultivar,indicating that the older cultivar was a strong competitor.Biomass yield,grain yield,harvest index,thousand-kernel weight,and kernel number per plant,were negatively correlated with PCP.Our results demonstrated that inter-cultivar competition affects maize productivity,and increasing PCP will decrease translocation of assimilates to grain and,ultimately,reduce yield.Therefore,there is a negative correlation between population competitive intensity and yield performance in maize,breeders should develop a communal ideotype that would not perform well in competition in future.

Response of Exotic Invasive Weed Alternanthera philoxeroides to Environmental Factors and Its Competition with Rice

A greenhouse experiment was conducted to determine the influence of the environmental factors such as low-temperature, drought stress, salt-alkali and flooding on the survival rate, propagation rate, fresh biomass and viability of the Altemanthera philoxeroides and its competitive ability against rice by using bioassay method. A high viability of 84% was found when the stems were treated at 4℃ and then grew under normal conditions, while no viable plant was noted when the stems were treated at -20℃ and grew under normal conditions. Compared to the fresh stem with water content of 93.5%, the survival rate, number of propagated stems and fresh biomass of A. philoxeroides derived from the stems with water content of 30.2% were reduced by 45%, 33% and 74% respectively. The treatments of 0.1% salt-alkaline solution led to loss of viability of A, philoxeroides. The stems of A. philoxeroides could grow in wet soil with different depths of water-layer. The A. philoxeroides at density of 23-180 plants/m^2 reduced the rice grain yield by 43-50% at the rice plant density of 100 plants/m^2.

Invasion syndromes:hypotheses on relationships among invasive species attributes and characteristics of invaded sites

As invasion science accepts that there is no single causal factor for biological invasion, the identification of groups of traits that are often associated, or ＂syndromes＂, is a logical move forward. Invasion syndromes are proposed to identify suites of site conditions （biotic and environmental） that render a site vulnerable to invasion by different types of invaders. This paper proposed four invasion syndromes which relate invader attributes （competitive ability, niche construction, phenotypic plasticity, and phenological niche separation） to the biotic characteristics （biodiversity and enemies） and environmental conditions （resource abundance and fluctuation） of invaded sites. The four invasion syndromes described in this paper are a development of hypotheses of how the many factors that influence species invasion might be associated. Invasion Syndrome 1 proposes that sites with relatively high resource abundance and high diversity should be vulnerable to invasion by species with high competitive ability. Invasion Syndrome 2 hypothesizes that sites with relatively low resource abundance and low diversity should be vulnerable to invasion by species with niche construction ability. Invasion Syndrome 3 postulates that sites with moderate or fluctuating resources and moderate diversity should be vulnerable to invasion by species with high phenotypic plasticity. Invasion Syndrome 4 hypothesizes that species introduced into a site where it has phenological niche separation from natives will not have to contend with interference from the biotic community at a site （diversity or natural enemies） and may invade where ever site environmental conditions suit its life history. Further work is needed to support, contradict, or refine these hypotheses and almost certainly will identify more invasion syndromes.

Root proliferation in native perennial grasses of arid Patagonia,Argentina

Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that （1） defoliation reduce net primary productivity, and root length density and weight in the native species, and （2） root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species （i.e., Aristida spegazzinfi, A. subulata and Sporobolus cryptandrus）. Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season （2008-2009）, cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid- and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den- sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

The application of business process re-engineering in Chinese enterprises

After joining in WTO,Chinese enterprises face more intense competitive environments. The problems, such as many foreign capital enterprises swarming into China, increasing market competitive ability, keeping on national and international market, have become more serious to enterprise’s decision maker. At the same time, the information technology is developing quickly, then business process re engineering will become valid path for enterprise increasing market competitive ability. As a case study, this paper applies Business Process Re engineering(BPR) approach to analyze a Chinese company.

Soil space and nutrients differentially promote the growth and competitive advantages of two invasive plants

Aims Invasive plants commonly occupy disturbed soils,thereby provid-ing a stage for understanding the role of disturbance-enhanced resources in plant invasions.Here,we addressed how soil space and soil nutrients affect the growth and competitive effect of inva-sive plants and whether this effect varies with different invaders.Methods We conducted an experiment in which two invasive plants(Bromus tectorum and Centaurea maculosa)and one native species(Poa pratensis)were grown alone or together in four habitats consisting of two levels of soil space and nutrients.at the end of the experiment,we determined the total biomass,biomass allocation and relative interaction intensity of B.tectorum,C.maculosa and P.pratensis.Important Findingsacross two invaders,B.tectorum and C.maculosa,increased soil nutrients had greater positive effects on their growth than increased soil space,the effects of soil space on root weight ratio were greater than those of soil nutrients,and their competitive effect decreased with soil space but increased with soil nutrients.these findings sug-gest that changing soil space and nutrients differentially influence the growth and competitive advantages of two invaders.Bromus tectorum benefited more from increased soil resources than C.mac-ulosa.soil space and nutrients affected the biomass allocation of C.maculosa but not B.tectorum.the competitive effect of B.tecto-rum was unaffected by soil space and soil nutrients,but the opposite was the case for C.maculosa.thus,the effects of soil space and nutrients on growth and competitive ability depend on invasive species identity.

Effects of generalist herbivory on resistance and resource allocation by the invasive plant, Phytolacca americana

Successful invasions by exotic plants are often attributed to a loss of co-evolved specialists and a re-allocation of resources from defense to growth and reproduction. However, invasive plants are rarely completely released from insect herbivory because they are frequently attacked by generalists in their introduced ranges. The novel generalist community may also affect the invasive plant＇s defensive strategies and resource allocation. Here, we tested this hypothesis using American pokeweed （Phytolacca americana L.）, a species that has become invasive in China, which is native to North America. We examined resistance, tolerance, growth and reproduction of plant populations from both China and the USA when plants were exposed to natural generalist herbivores in China. We found that leaf damage was greater for invasive populations than for native populations, indicating that plants from invasive ranges had lower resistance to herbivory than those from native ranges. A regression of the percentage of leaf damage against mass showed that there was no significant difference in tolerance between invasive and native populations, even though the shoot, root, fruit and total mass were larger for invasive populations than for native populations. These results suggest that generalist herbivores are important drivers mediating the defensive strategies and resource allocation of the invasive American pokeweed.

Effects of latitudinal variation on field and common garden comparisons between native and introduced groundsel(Senecio vulgaris)populations

Aims Field and common garden comparisons are commonly performed to test the rapid evolution of increased vigor in introduced plant populations.Latitudinal dines in phenotypic traits can obscure such evolutionary inferences,particularly when native or introduced populations are distributed across large geographic ranges.We tested whether the latitudinal dines influence comparisons between introduced and native populations of Senecio vulgaris.Methods Senecio vulgaris is native to Europe but has been introduced in northeastern and southwestern China.To evaluate the performance in terms of growth and reproduction between native European populations and introduced Chinese populations,we compared plant height,number of branches and number of capitula in field populations in native and introduced ranges and in a common garden in Switzerland.Important Findings The introduced Chinese populations performed better than the native European populations in the field in terms of plant height and number of capitula,which was consistent with the prediction of the evolution of the increased competitive ability(EICA)hypothesis.The Chinese populations produced more capitula than the European populations when the latitudinal cline was considered in the common garden comparison.When we compared the traits of the northeastern Chinese,southwestern Chinese and European populations in both the field and common garden,the northeastern Chinese populations,at latitudes similar to those of the European populations,exhibited greater plant size and more capitula than the European populations in both the field and common garden.However,the southwestern Chinese populations,at latitudes much lower than those of the European populations,did not perform better than the native populations in terms of reproduction.In conclusion,our results suggest that latitudinal dines in phenotypic traits should be considered in field and common garden comparisons when introduced populations are geographically structured.