浅谈核心力量训练对游泳运动员自由泳打腿技术的影响

本文针对核心力量在游泳运动训练中的作用、与传统力量训练的关系及注意事项进行了探讨。研究发现,随着自由泳技术的发展,对核心力量训练水平的要求越来越高。将核心力量训练与传统力量训练有效地结合,满足专项体能与技术的要求,有利于游泳运动员技术水平的提高。     

我国软件企业发展出路

在中国软件业迅速发展中 ,软件企业“散、乱、小”的问题日益突出 ,制约了产品质量和行业整体效益的提高。文章认为 ,在提高行业组织化管理水平的基础上 ,通过实体联合和虚拟联合的形式 ,整合行为资源 ,是目前行业健康发展的选择     

Ecophysiological growth characteristics and modeling of the onset of the spring bloom in the Baltic Sea

The onset of spring bloom in temperate areas is a transition period where the low productive, winter phytoplankton community is transformed into a high productive spring community. Downwelling irradiance, mixing depth and the ability of the phytoplankton community to utilize the light, are key parameters determining the timing of the onset of the spring bloom. Knowing these parameters would thus provide tools for modeling the spring bloom and enhance our knowledge of ecophysiological processes during this period.Our main objective with this study was to provide data for the growth characteristics of some key species forming the spring bloom in the Gulf of Finland, and to apply those results in a simple dynamic model for the onset of the spring bloom, in order to test if the timing of the spring bloom predicted by the models corresponds to field observations. We investigated the photosynthetic characteristics of three diatoms and two dinoflagellates (Chaetoceros wighamii, Melosira arctica, Thalassiosira baltica, Scrippsiella hangoei and Woloszynskia halophila), at low temperatures (4–5 °C). All of these species are common during spring bloom in the Baltic Sea.Cultures of these species were acclimated to different irradiance regimes prior to measurements of photosynthesis, respiration, pigment concentration and light absorption. We did not find a positive relationship between respiration and growth rate, and we hypothesize that this relationship, which is well established at higher temperatures, is negligible or absent at low temperatures (< 10 °C). Photosynthetic maximum (P_m), and maximum light utilization coefficient (α) was lowest and respiration (R) highest in the dinoflagellates.We made a model of the onset of the spring bloom in the western part of Gulf of Finland, using the obtained data together with monitoring data of mixing depth and water transparency from this area. Model results were compared to field observations of chlorophyll-a (Chl-a) concentration. There was a good agreement between the model predictions and the observed onset of the spring bloom for the diatoms. S. hangoei, however, was not able to reach positive production in the model, and W. halophila had the similar growth characteristics as S. hangoei. Consequently, these species must have other competition strategies enabling them to exist and grow during spring bloom.     

关于码头超能力靠泊问题的分析

文中通过对我国沿海港口建设和生产发展状况进行分析，指出了产生码头超能力靠泊的原因，并深入讨论了码头超能力靠泊的危害，最后，从提高码头生产效率、遵守限定条件靠泊核准的新船型等方面提出了解决码头超能力靠泊的方法。     

以客户为中心的核心竞争力战略定位分析

从实践看,核心竞争力已成为企业成长的重要武器。中国企业只有确立以客户为中心的核心竞争力战略定位,才能在国际竞争中生存与发展。以客户为中心,并不是以客户所有的价值为中心,去满足客户所有的需要,而是取决于公司的战略定位。本文主要从市场竞争战略定位的角度阐述了核心竞争力战略定位:差异化战略、聚焦战略与成本领先战略。     

采用斜撑加劲的超宽混凝土梁断面设计与施工

采用内外斜撑加劲的混凝土梁作为宽幅桥梁一种典型断面在国外桥梁建设实践中占有一席之地,但在国内却鲜有采用。从典型断面布置、关键节点构造、桥面板计算、施工工艺等方面出发,结合其在国外桥梁建设中的具体应用,阐述该种断面桥梁的合理结构形式及其技术发展趋势,旨在为宽幅桥梁的建设提供新的思路。     

磁电式速度传感器设计与应用

分析磁电式速度传感器早期产品故障现象,对传感器进行了改进设计,得出设计要点,阐述了传感器应用须注意的问题。改进设计已成功应用于为GE公司开发的3款磁电式速度传感器上。     

Airport and airlines competition: Incentives for vertical collusion

This paper develops a model of airport and airline competition in a three-stage game. We analyse incentives for vertical collusion between one airport and one airline that compete with another airport and another airline, by means of static and dynamic games. We find that incentives for collusion exist when airports and airlines have different market sizes and, under certain conditions, also when secondary airports and low cost airlines compete with main airports and full service airlines.     

浅谈吉怀高速梁家院子隧道软弱围岩施工关键工艺

基于隧道施工过程中软弱围岩施工质量、安全控制十分困难。经长期对本软弱围岩隧道的现场施工管理,对软弱围岩的施工控制提出些许见解,并用工程实际情况予以证明。     

基于多尺度方法的桥桩稳定性评估

通过桥梁检测、桥下桩基抽芯及抽检桩全孔壁摄像试验等多种尺度研究246省道胥河大桥南岸边坡滑移对桥桩基础稳定性的影响。根据检测结果,评定桥梁技术状况为五类桥,且大桥南岸边坡有整体滑移趋势,建议及时封桥停用,并对南岸进行地质详勘,进一步提出治理大桥病害的工程措施,以策安全。