科技型人才聚集效应的支持系统研究

科技人才是人才资源中重要的宝贵资源,科技人才聚集效应是人才流动的结果,是人才聚集现象从量变到质变的转化。通过对科技型人才聚集效应的支持系统研究,可知科技型人才聚集效应的实现与多种因素密切相关,这些因素相互联系、相互作用,共同构成科技型人才聚集效应的支持系统。     

论人力资本聚集效应

人力资本的聚集效应在各种正式或非正式的群体中发挥着重要作用 ,但始终没有被提升到理论的高度来研究。本文首次提出了人力资本聚集效应这一概念。研究人力资本聚集效应的意义是利用其特点来营造有利于产生人力资本聚集效应的环境 ,提高企业经营管理水平 ,加快企业知识创新的进程     

领导行为对科技型人才聚集效应的影响

在论述科技型人才聚集现象和聚集效应的基础上,分析了领导行为的类型和特征,从维度层次结构的视角,分别探讨了交易型领导行为、变革型领导行为和家长式领导行为对科技型人才聚集效应的作用机理。认为各类领导行为对科技型人才聚集的影响不同,比较而言,变革型领导行为更能提高组织的绩效,对科技型人才聚集效应的积极影响更强。     

聚集效应与西部小城镇发展战略研究

聚集效应是小城镇经济运行的内在规律,本文通过对聚集效应的分析,结合我国西部小城镇建设的具体实践,论证了西部小城镇发展的战略选择,分析了西部小城镇聚集障碍及实施措施。     

基于多产品或客户供应链订购聚集效应研究

对于供应链中多种产品或多个客户的订购策略,建立了3种订购策略的模型(单独订购策略、联合订购策略、搭载订购策略),并分别构建了3种订购策略的总成本函数.通过对3种订购策略聚集效应的分析,得出:搭载订购策略的聚集效应明显优于联合订购策略,而联合订购策略的聚集效应优于单独订购策略;当附加订购成本在总订购成本中占有较大的比重时,搭载订购策略可使总成本最小,其聚集效应明显;当附加订购成本在总订购成本中占有较小的比重时,则搭载订购策略变得不可行,联合订购策略会使总成本更小.     

科技型人才聚集效应刍议

科技型人才是人力资源中最具创造力的群体.科技型人才的流动形成了科技型人才的聚集,其聚集现象则会产生科技型人才聚集效应.本文主要对科技型人才聚集效应的环境因素进行分析与研究,并提出其优化对策和方法.     

基于和谐管理的国有企业人才聚集效应与技术创新研究

国有企业是我国国民经济的主体,也应是技术创新的主体。技术创新的关键是人才,而人才的聚集产生的聚集效应能有效地推动技术创新的发展。在分析人才聚集效应的基础上,运用和谐管理的思想,对国有企业如何提升技术创新能力进行了研究。     

宿主-寄生物种群模型的复杂动态

通过数值模拟试验,分析了几种宿主-寄生物相互作用的差分方程模型随参数变化时表现出的复杂动态行为以及行为所发生的质的变化.结果表明:各种类型的模型尤其是聚集效应模型都包括多种复杂的动态:Hopf分支、倒转Hopf分支、倍周期分支、倒转倍周期分支(周期倍减)、草叉分支、倒叉分支、吸引子突变(危机),含有窄、宽周期窗的混沌段、多吸引子共存、阵发混沌及超变换行为.这些非单一的复杂动态对了解自然界种群的动态规律有重要意义.     

钻地弹爆炸聚集效应研究现状及展望

对国内外多弹爆炸聚集效应研究现状进行了系统的总结，指出今后发展方向。研究钻地弹爆炸聚集效应，需要从能量耦合、侵彻爆炸耦合、应力波的相互作用以及岩土介质的状态方程和统一应力变关系等方面来进行考虑。     

虚拟团队与管理创新

本文围绕着虚拟团队的管理理论与管理创新进行了较为深入系统的研究 :介绍了虚拟团队的内涵和特点 ;引入了人力资本聚集效应的概念 ,分析了人力资本聚集效应在构建虚拟团队中的重要作用 ;说明了虚拟团队理论的出现为研究企业特别是中小企业的发展和技术创新提供了一个良好的契机 ,信息革命为虚拟团队理论的应用提供了广阔的空间     

Host plants influence parasitism of forest caterpillars

Patterns of association between herbivores and host plants have been thought to reflect the quality of plants as food resources as influenced by plant nutrient composition, defences, and phenology. Host-plant-specific enemies, that is, the third trophic level, might also influence the distribution of herbivores across plant species. However, studies of the evolution of herbivore host range have generally not examined the third trophic level, leaving unclear the importance of this factor in the evolution of plant-insect herbivore interactions. Analysis of parasitoid rearings by the Canadian Forest Insect Survey shows that parasitism of particular Lepidoptera species is strongly host-plant-dependent, that the pattern of host-plant dependence varies among species of caterpillars, and that some parasitoid species are themselves specialized with respect to tree species. Host-plant-dependent parasitism suggests the possibility of top-down influence on host plant use. Differences in parasitism among particular caterpillar-host plant combinations could select for specialization of host plant ranges within caterpillar communities. Such specialization would ultimately promote the species diversification of Lepidoptera in temperate forests with respect to escape from enemies.     

人工繁殖白蛾黑基啮小蜂最适交配期和暴露期的选择

以蛹蜂比为1∶100和柞蚕(Antheraea pernyi Guerin-Meneville)蛹为替代寄主繁殖白蛾黑基啮小蜂(Tetrastichus nigricoxae Yang),测定室内人工繁蜂的最适交配期和接蜂暴露期。结果表明:当小蜂羽化出蜂后交配48～72 h时,寄生率(93.3%～94.2%)、羽化率(87.5%～90.8%)和平均子代出蜂量(1 010.4～1 213.3头)等寄生指标,均高于或显著高于24 h时的值(p<0.05),极显著高于0 h和96～144 h时(p<0.01)的值;当寄主蛹暴露给寄生蜂2～3 d时,寄生率(87.5%～95.8%)、羽化率(86.7%～95.8%)和平均子代出蜂量(1 274.5～1 365.6头)等繁蜂指标也高于或显著高于其他暴露期处理(p<0.05)。综合考虑蜂龄对寄生效果的影响,选择白蛾黑基啮小蜂人工繁殖的最适交配期和暴露期分别为羽化出蜂后2 d和2～3 d。     

Proteome changes in the plasma of Papilio xuthus (Lepidoptera: Papilionidae): effect of parasitization by the endoparasitic wasp Pteromalus puparum (Hymenoptera: Pteromalidae)

Although the biochemical dissection of parasitoid-host interactions is becoming well characterized, the molecular knowledge concerning them is minimal. In order to understand the molecular bases of the host immune response to parasitoid attack, we explored the response of Papilio xuthus parasitized by the endoparasitic wasp Pteromalus puparum using proteomic approach. By examining the differential expression of plasma proteins in the parasitized and unparasitized host pupae by two-dimensional (2D) electrophoresis, 16 proteins were found to vary in relation to parasitization compared with unparasitized control samples. All of them were submitted to identification by mass spectrometry coupled with a database search. The modulated proteins were found to fall into the following functional groups: humoral or cellular immunity, detoxification, energy metabolism, and others. This study contributes insights into the molecular mechanism of the relationships between parasitoids and their host insects.     

Parasitoid secretions provoke ant warfare

Insect social parasites are extreme specialists that typically use mimicry or stealth to enter ant colonies to exploit the rich, but fiercely protected, resources within their nests. Here we show how a parasitic wasp (parasitoid) contrives to reach its host, itself an endangered species of social parasite that lives inside the brood chambers of ant nests, by releasing semiochemicals to induce in-fighting between worker ants, locking the colony in combat and leaving it underprotected. Four of these chemicals are new to biology and have the potential to control pest species by inducing different agonistic behaviours in ants.     

云南省柑桔蚧虫的寄生蜂初报

报道从云南省柑桔蚧虫育出的寄生蜂３４种，隶属２个总科、６个科、２４个属；其中９种为云南省新记录，指出了常见蚧虫的主要寄生蜂，对３个我国未报道而在云南常见的种作了简要记述并附特征图。     

Host-parasitoid associations in patchy environments

Studies of insect host-parasitoid interactions have contributed much to the consensus that spatial patchiness is important in the regulation of natural populations. A variety of theoretical models predict that host and parasitoid populations, although unstable in the absence of environmental heterogeneity, may persist at roughly steady overall densities in a patchy environment owing to variation in levels of parasitism from patch to patch. Observed patterns of parasitism, however, have a variety of forms (with variation in attack rates among patches depending directly or indirectly on host density, or showing variation uncorrelated with host density). There is some confusion about the dynamical consequences of these different forms. Here we first show how the dynamical effects of all these forms of environmental heterogeneity can be assessed by a common criterion. This 'CV2 greater than 1 rule' states that the overall population densities will remain roughly steady from generation to generation if the coefficient of variation squared (CV2) of the density of searching parasitoids in the vicinity of each host exceeds approximately unity. By partitioning CV2 into components, we show that both direct and inverse patterns of dependence on host density, and density-independent patterns, all contribute to population regulation in the same way. Second, we show how a maximum-likelihood method can be applied to the kind of field data that are usually available (that is, percentage parasitism versus local host density) to estimate the components of CV2. This analysis indicates that heterogeneity is large enough to stabilize dynamics in 9 of 34 published studies, and that density-independent heterogeneity is the main factor in most cases.     

外睾吸虫种群动态研究

外睾吸虫(Exorchis sp.)是控制日本血吸虫(Schistosoma ja ponicum)在其宿主钉螺(Oncomelania hupensis)体内发育的一个有利用价值的生物资源.掌握外睾吸虫种群的变化规律,对于进一步研究血吸虫病的生物防治有着重要的意义.对鲶鱼(Silurus asotus)肠道内寄生的外睾吸虫的种群动态进行研究,研究结果表明,不同月份外睾吸虫在鲶鱼体内的感染率、种群平均密度和感染强度无明显的变化规律.外睾吸虫在不同体长宿主体内的感染率变化范围在65.38％～91.98％,宿主体长在270mm以下时,外睾吸虫的感染率随着宿主体长的增加而逐渐增大.外睾吸虫在宿主体内的频率分布表明,多数宿主只感染少量的外睾吸虫,而较大量的外睾吸虫只感染少数的宿主.吸虫种群在不同月份和不同体长宿主体内的分布类型均属于聚集分布,在不同体长组宿主中聚集强度随着种群密度增加而增强.     

Role of ethylene signaling in the production of rice volatiles induced by the rice brown planthopper Nilaparvata lugens

In response to herbivory, plants release volatiles to attract the natural enemies of herbivores[1,2]. This phe- nomenon has been reported in more than 23 plant spe- cies[3―6], and several field studies have shown that these herbivore-induced volatiles en…     

基于图演化事件的主机群异常检测模型

针对网络环境中出现的以服务为聚合的通信行为和以分布式攻击为典型的新型协同攻击模式,提出了基于图演化事件的主机群异常检测模型。分析了行为主体潜在的社会化关系、聚集成簇的主机群及其群体行为的动态特性,该模型具有无参数、数据量级可扩展的特点。定义并提出了图动态演化事件及检测算法,实现异常主机群检测。本模型在Spark上实现和部署,还从实际计算机和网络环境提取数据进行分析和验证。实验结果表明,该模型能够有效刻画群体行为,揭露重要的图演化事件,准确定位异常发生的主机群,其群成员主机的检测率达到95.09%。