单边独立和的完全收敛性

自许宝騄和Robbins提出了完全收敛性概念以来,经许多学者努力,已获得了丰富成果。本文利用慢变化函数的性质改进了[2]中的部分结果。引理1 设l(X)>0为x→+∞的慢变化函数,     

Mitochondrial DNA variation in geographic populations of Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera; Chrysomelidae)

Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.     

辽宁省人口数据库应用系统的设计和实现

本文论述了采用软件工程的科学方法对辽宁省人口数据库应用系统的结构设计和功能设计的过程,同时阐述了如何有效地对本系统的软件支撑环境的开发和应用。     

Evolutionary and ecological consequences of interspecific hybridization in cladocerans

The evolutionary process of interspecific hybridization in cladocerans is reviewed based on ecological and population genetic data. The evolutionary consequences of hybridization, biogeographic patterns and fitness comparisons are analyzed within the conceptual framework of theories on hybridization. Among species of theD. longispina complex no interpopulational transition zones (hybrid zones) have been detected, but rather patchy distributions of hybrids and parentals have been found. Hybrids occur across broad geographic ranges and can be more abundant than parental species. Due to asexual reproduction (ameiotic parthenogenesis), hybrid breakdown can be avoided, and hybrids can even (temporarily) combine advantageous traits of both parental species. Evolutionary consequences may arise from repeated backcrossing, which in some cases results in introgression and patterns of reticulate evolution.Those forms which possess in some considerable degree the character of species, but which are so closely similar to some other forms, or are so closely linked to them by intermediate gradations, that naturalists do not like to rank them as distinct species, are in several respects the most important to us (Charles Robert Darwin 1859)     

变质量锭子系统对自身不均衡的强迫响应

在纺纱过程中,纱线不断卷绕到纱管上去,锭子纱管系统是变质量系统,本文利用摄动法对其动力学方程求解。得出如下结论:变质量的锭子纱管系统临界转速形成为一区域,锭子设计应避开这一区域.     

Population biology of figs: Applications for conservation

Summary The flowering phenology typical of at least monoecious figs-intra-tree synchrony and inter-tree asynchrony-poses problems for persistence of the pollinator population, and hence of the fig population itself, when fig population size is small. Establishment and maintenance of a population of the short-lived, species-specific wasp pollinator require that the fig population include a critical minimum number of trees (critical population size: CPS). Below CPS, temporal gaps between flowering trees occur that are unbridgeable by the pollinator, leading to its local extinction. This has implications for conservation in two contexts: human-aided invasions of introduced fig/wasp pairs, in which initial populations of figs and/or wasps may be small, and the persistence of figs and wasps in fragmented forest, in which initially large populations may be drastically reduced. Long-distance range extension by fig/wasp pairs is problematical for two reasons: 1) the fig species must first attain CPS, most likely through repeated seed dispersal events, before the wasp can establish; and 2) long-distance transit should be difficult for the tiny, short-lived wasp pollinators. I review the biology of natural and human-aided range extension by figs and fig wasps, and show that in human-aided range extensions these two difficult steps are circumvented. Once introduced into an area where hosts are abundant, fig wasps should readily establish from a small number of initial colonists, since they mate before dispersal and are highly tolerant of inbreeding. They are thus less subject than many insects to the genetic and demographic hazards of small population size. Of 5–6 fig/wasp pairs that have performed human-aided long-distance range extensions, one Asian pair,Ficus microcarpa and its pollinatorParapristina verticillata, is established in numerous areas in the northern neotropics, and the plant may become a serious weed. In tropical forests, figs may provide keystone resources for frugivores, providing fruit during seasons when other resources are scarce. Figs pose difficult problems for conservation biology, since minimum viable populations appear to be large, and since many species of tropical rainforests occur at low densities. This means that minimum areas required for persistence of a fig population- and for those of other species that would be affected were figs to be removed from the system-may often be large.     

The Age Distribution Model and the Parity Progressive Model of Population and Their Equivalence

This paper proved that the integral form and the intero-differential form of the agestructured population equation(Lotka model) are equivalent, the integral form and the integrodifferential form of the parity prongressive population equation(Henry model)are equivalent. By the age parity progressive model, the equivalence between Lotka model and Henry Model is also proved. Moreover. the relation between the parity progression ratio and the total fertility rate is giver.     

E-E energy transfer rate for the reaction of N_2(a~1Π_g)+CO(X~1∑)→CO(A~1Π)+N_2(X~1∑_g)

The metastable N_2(a~1 Π_g, v~′) is not only one of the most important energy carriers in the discharge of nitrogen, but also one of the most prominent ultraviolet molecular emission source in the ionosphere. Knowledge of its energy transfer processes is important for chemical lasers, atmosphere chemistry and remote sensing applications. In 1972, Golde and     

线性时变系统的一种预报方法

】本文首先介绍了基于最小二乘参数估计的传统预报方法和多层递阶预报方法，然后针对这两种方法的特点及存在的问题，提出了线性时变系统的一种新的预报方法。这种方法具有预报精度高，受参数估计初值选取的影响小的特点     

人口与环境可持续发展

人口、资源、环境组成一个相互依存的巨大系统，呈良性、中性和恶性循环。人口环境系统性质：一是既对立又统一的自然社会系统；二是高度融合的有机整体；三是基本矛盾为其发展动力。人口环境系统动因包括人口环境运动的推动、关系的调整和规律的作用。地球环境系统被人口压力突破后表现出：矛盾的滞后性、影响的多重性和经济陷于衰退。人口过多、素质偏低和老龄化加快三症并发，成为中国人口与环境发展的独特现象。可持续发展是实现人口与环境协调发展的科学、合理的社会结构范式，是自然的人化与人的自然化的理想蓝图和必由之路。