关于确定生存群与资金流的计算机程序

Java是目前最流行的软件开发语言之一,称为网络上的"世界语"。Java建立在C和C++之上,使熟悉C、C++的程序员能方便地运用Java进行编程。Java摒弃了C、C++中许多不合理的特性,具有简单高效、面向对象、不依赖于机器结构的特点,支持多线程、分布和并发机制。Java在可移植性、健壮性、安全性方面大大优于已存在的其他编程语言。Java提供了丰富的类库,可广泛用于面向对象事件描述、企业型应用开发,Internet系统管理、网页设计、可视化软件开发。Java的应用必将对整个计算机产业产生深刻影响,从根本上变革软件的设计风格、设计方法和设计过程。

联合生存状态与Gompertz死亡力(英文)

本文证明了对任一生存群,如果对于任何联合生存状态的个体,总可以找到一服从此群体的死亡力的个体,使得二者的生存分布相同,则群体一定服从Gompertz死亡力.本文的结果,说明了生存群体中的联合状态的个体的生存分布可由生存群体中单生命个体的生存分布来代替的充要条件是,生存群服从Gompertz死亡力.

Genetic improvement on Chinese shrimp (Fenneropenaeus chinensis):growth and viability performance in F1 hybrids of different populations

Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea （WYP）, and the west coast of the Korean Peninsula and coast （WKN）. The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea （FKN）, the Huang Hai （the Yellow Sea in Chinese） No.1 （HH1）, and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length （BL）, carapace length （CL）. carapace width （CW）, height of the second and third abdominal segment （HST）, width of the second and third abdominal segment （WST）, length of the first abdominal segment （LF）, length of the last abdominal segment （LL）, live body weight （BW）, and survival rate were measured, Different combinations were statistically performed with ANOVA and Duncan＇s Multiple Range Test. The results show that the survival rate of JK98（♀）×WKN（♂） was the highest, followed by WYP（♀）×WKN（♂）, FKN（♀）×WYP（♂）, FKN（♀）×HHI（♂） and WYP（♀）×FKN（♂）; the body weight of FKN（♀）×HHI（♂） was the highest, followed by FKN（♀）×WYP（♂）, WYP（♀）×WKN（♂）, WYP（♀）×FKN（♂） and JK98（♀）×WKN（♂）; the total length had the same ranking as the body weight. All growth traits in hybrids JK98（♀）×WKN（♂） were the lowest among all combinations. F1 hybrids had significant difference （P〈0.05） in BL, CL, HST, LL, and BW; and insignificant difference （P〉0.05） in other growth traits and survival rate. The results of Duncan＇s Multiple Range Test are that BL and CL of JK98（♀）×WKN（♂） were significantly different from the other combinations; HST different from the combination of FKN（♀）×WYP（♂）, FKN（♀）×HHI（♂） and WYP（♀）×WKN（♂）; and BW different from FKN（♀）×WYP（♂） and FKN（♀）×HHI（♂）. As a whole, the results indicate that the FKN（♀）×HHI（♂） was the best combination in all growth traits. Therefore, hybridization can introduce the variation to base populations. The systematic selection program based on additive genetic performance may be more effective than crossbreeding.

An approach on the survivorship of giant panda in wild

The endangered giant panda (Ailuropoda melanoleuca) is endemic to th e mountains of Sichuan, Gansu and Shaanxi Provinces in China. The species had nu mbered over 2000 animals in early 1970s, but declined to no more than 1,000 anim als fragmented into perhaps 32 subpopulations in late 1990s as the result of num erous detrimental forces such as habitat shrinking, poaching and bamboo flowerin g. The mass flowering and followed die-off of bamboo played key roles in the dec lination of panda population in the past three decades. It trigged the starvatio n and following high mortality of giant pandas in 1970s over Min Mountains and i n 1980s across Qionglai Mountains in Sichuan Province. The situation of survivor ship is made worse by the fact that the panda habitat is fragmented into many sm all 'islands', each containing only a few pandas. Such small, isolated panda pop ulations are rendered even more vulnerable to extinction form threats such as ha bitat degradation, natural disaster, disease, and the deleterious effects of inb reeding. So restoring the panda habitat and reintroduction pandas to their histo rical habitat might be an important issue for protecting the giant panda in wild .

The Analysis of Growth and Reproduction of Industrial Clusters Based on View of Ecological Coexistence

The behavior of industrial cluster is similar to the behavior of biological population, that is, the industrial cluster is seemed to be an ecological symbiotic system. The relationship between economic organizations in the industrial cluster is similar to the relationship of species in ecological system, and symbiotic reciprocity, competition and cooperation are the basic. The ecological development is mainstream and direction of industrial cluster. In this paper, firstly, we studied the ecological symbiosis growth model of industry cluster, and tbund it being according to logistic growth model; secondly, we studied the growth and reproduction of economic organizations in industrial cluster in three different cases, which with only competition relations, only beneficial relations, and both competition and beneficial cooperation relationship between economic organizations, and finally, we determined the number of economical organizations when the industrial cluster attained ecological equilibrium.

Survival analysis of a stochastic single-species population model with jumps in a polluted environment

This paper is concerned with a stochastic single-species system with Levy jumps in a polluted environment. Some sufficient conditions on extinction, non-persistence in the mean, weak persistence in the mean, strong persistence in the mean, stability in the mean and stochastic permanence are obtained. The threshold between extinction and weak persistence in the mean is established. At the same time, under a simple condition, it is proved that this threshold also is the threshold between extinction and stability in the mean. The results reveal that L@vy jumps have significant effects to the persistence and extinction results.

An ecological model with the p-Laplacian and diffusion

We study the existence of positive solutions of a population model with diffusion of the form {-△pu=aup-1-f（u）-c/ua,x∈Ω,u=0,x∈Ω where △p denotes the p-Laplacian operator defined by △pz =div（｜z｜P-2z）, p 〉 1, Ω is a bounded domain of RN with smooth boundary, α∈ C （0, 1）, a and e are positive constants. Here f ： [0, ∞） → R is a continuous function. This model arises in the studies of population biology of one species with u representing the concentration of the species. We discuss the existence of positive solution when f satisfies certain additional conditions. We use the method of sub- and super-solutions to establish our results.

Evidence of functional and structural changes in the microbial community beneath a succulent invasive plant in coastal dunes

Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucial importance to maintain plant diversity due to harsh environmental conditions,water limitation and nutrient scarcity.Invasive alien plants represent a major threat to ecosystem conservation.Here,we explored different impacts of Carpobrotus edulis,a succulent plant invading coastal areas worldwide,on the function and structure of bacterial communities.Sand represents a challenging substrate due to low organic matter content and limited microbial activity.We optimized bacterial extraction for functional evaluation before assessing ecosystem impacts produced by C.edulis.We compared 12 extracting procedures combining different soil storage,sample amount and extracting solutions on the functional activity of sand communities through the community-level physiological profile.We further explored the function(using Biolog Ecoplates)and structure[using polymerase chain reaction–denaturing gradient gel electrophoresis(PCR-DGGE)]of bacterial communities from dunes invaded by C.edulis.Saline solution consistently increased bacterial cells detected by cytometry(P≤0.001).Principal component analysis suggested a limited temporal framework(0–24 h)in which community function can be explored without significant alterations in C substrate consumption.Changes under C.edulis invasion exhibited a different pattern of C substrate utilization comparing native and non-native zones(interspecific),but also between native zones(intraspecific),suggesting that functional impacts are site-dependent.Complementary,results obtained from PCR-DGGE indicated that the bacterial community structure of native dunes significantly differed from dunes invaded by C.edulis.