浅谈钢波纹管涵施工工艺及经济性分析

结合广源高速公路钢波纹管涵工程施工,对钢波纹管涵施工工艺控制及主要技术要求进行了浅述,并对比分析了钢波纹管涵的经济性及特点,指出了该工程通过钢波纹管涵的施工,取得了良好的效果。     

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。     

论高速公路区域经济综合开发

高速公路与区域经济存在着相互依存、相互促进的辩证关系。将高速公路投资经营与区域经济相结合,可以实现高速公路区域经济一体化协调发展。     

抢抓机遇，加快辖区公路建设，为县域经济发展服务

按照市场经济的思维方式,抢抓机遇,不等不靠,采取多渠道、多形式筹措资金,加快辖区公路建设步伐,为地方经济建设服务。     

市场经济下的工程量清单计价与定额计价的思考

我国的工程造价长期以来按照传统的定额模式进行计价，目前推行工程量清单计价模式。工程量清单计价模式实行量价分离，由企业根据自身情况按市场规律自主报价，但是，工程量清单计价模式在并不成熟的市场经济条件下还不能彻底取代传统的定额计价模式，按定额编制概（预）算的造价管理方法仍然具有不可替代的作用，尽管如此，工程量清单计价的推行乃大势所趋。     

港口集装箱运输与区域经济发展互动关系研究——以长江三角洲港口群为例

利用生产函数增长模型及灰色关联分析方法,探讨了长三角地区港口集装箱吞吐量与区域经济之间的互动关系,定量计算两者之间存在的关联度及港口生产指标对于经济增长的贡献,对长三角港口群与区域经济协调发展进行针对性分析.     

轨道交通区域快线车辆检修修程研究

随着城市轨道交通发展,区域快线对车辆日常维护检修提出新的要求,科学合理的车辆检修标准既能提高列车可靠性和投运率,同时可以避免过度修,节约资源。通过对车辆检修修程的影响因素及目前国内主要轨道交通日常维护及检修修程进行研究,结合在建区域快线项目的特点,提出区域快线车辆检修修程研究成果,为区域快线的建设提供理论依据。     

再制造循环物流研究中值得关注的几个问题

在简述再制造、再制造物流国内外现状基础上，根据循环经济特征和再制遗物流特征，提出了与循环经济特征一致的再制造循环物流新概念。重点阐述了当前我国再制造循环物流应关注的几个关键问题，以及研究每个问题过程中应实现的研究目标和应采取的研究策略。提出了通过再制造循环物流与新品正向物流的集成来降低循环物流成本的有效措施，讨论了再制造循环物流与新品正向物流的集成模式及其应用范围。