夏热冬暖地区地铁车站水冷直膨式空调机组的综合部分负荷性能指标评价

对地铁车站水冷直膨式空调机组综合部分负荷性能指标(IPLV)的评价方法进行研究。以IPLV的评价理论为指导,结合广州地区的气象条件和地铁典型车站,得出夏热冬暖地区地铁车站公共区的建筑热负荷特性,分析并计算IPLV的权重系数,讨论水冷直膨机组名义工况及部分负荷的测试工况条件,确定了适用于夏热冬暖地区地铁车站水冷直膨式空调机组IPLV的计算公式。为我国城市轨道交通车站直膨式空调机组国家标准制定提供参考。     

夏热冬冷地区重交通钢桥面铺装技术应用

夏热冬冷地区重交通钢桥面铺装对钢板防护、混合料高温稳定性和低温抗裂性要求较高,同时需兼顾沥青混合料的耐久性和施工和易性。通过对全国典型钢桥面铺装的调研和分析,判断沙尔沁互通立交钢桥面浇注式沥青混凝土铺装设计的合理性,通过关键施工控制措施,使该种铺装结构在沙尔沁互通立交顺利实施。     

Size-fractionated phytoplankton biomass and species composition in the Indian sector of the Southern Ocean during austral summer

During the late austral summer of 1994, Antarctic waters were characterized by low phytoplankton biomass. Along the 62°E meridian transect, between 49°S and 67°S, chlorophyll (Chl.) a concentration in the upper 150 m was on average 0.2 mg m⁻³. However, in the Seasonal Ice Zone (SIZ) chlorophyll a concentrations were higher, with a characteristic deep chlorophyll maximum. The highest value (0.6 mg Chl. a m⁻³) was measured at the Antarctic Divergence, 64°S, corresponding to the depth of the temperature minimum (100 m). This deep biomass maximum decreased from South to North, disappeared in the Permanently Open Ocean Zone (POOZ) and reappeared with less vigour in the vicinity of the Polar Front Zone (PFZ). In the SIZ, the upper mixed layer was shallow, biomass was higher and the >10 μm fraction was predominant. In this zone the >10 μm, 2–10 μm and <2 μm size fractions represented on the average 46%, 25.1% and 28.9% of the total integrated Chl. a stock in the upper 100 m, respectively. The phytoplankton assemblage was diverse, mainly composed of large diatoms and dinoflagellate cells which contributed 42.7% and 33.1% of the autotrophic carbon biomass, respectively. Moving northwards, in parallel with the decrease in biomass, the biomass of autotrophic pico- and nanoflagellates (mainly Cryptophytes) increased steadily. In the POOZ, the picoplanktonic size fraction contributed 47.4% of the total integrated Chl. a stock. A phytoplankton community structure with low biomass and picoplankton-dominated assemblage in the POOZ contrasted with the relatively rich, diverse and diatom-dominated assemblage in the SIZ. These differences reflect the spatial and temporal variations prevailing in the Southern Ocean pelagic ecosystem.     

不同敏感性参数下船舶-碎冰碰撞的船体结构响应

基于我国第七次北极科学考察获得的夏季北极海冰空间分布情况,模拟真实碎冰分布,采用LS-DYNA软件中的流固耦合方法,研究在船舶航速、碎冰尺度、碎冰厚度及碎冰密集度等因素影响下船舶-碎冰碰撞的船体结构响应。结合试验数据得到船体结构的应力、吸能和碰撞力。结果表明：船舶-碎冰的主要碰撞区域为艏部及舷侧的水线附近;在船舶航行于碎冰域时,船体结构的应力、吸能和碰撞力的峰值随碎冰域的船舶航速、碎冰尺度、碎冰厚度及碎冰密集度的增加而增加,但分布情况不同。研究结果为船舶在极地冰区航行提供一定的安全性参考。     

预制箱梁混凝土夏季施工质量控制浅谈

该文阐述了预制箱梁混凝土夏季施工的具体质量控制,并着重介绍了施工过程中的工序工艺控制要素、事故预防及处理。从而较好地控制质量,预防、减少或杜绝质量事故的发生。     

梨香溪特大桥承台大体积混凝土温度裂缝控制技术

结合梨香溪特大桥承台大体积混凝土夏季施工实践,简述了温度裂缝产生的原因,介绍该桥承台砼施工中采取选择合理的施工方案、严密施工组织管理、在承台砼浇筑前布设冷却水管、加强砼浇筑及养生过程中的温度控制等防止承台大体积砼裂缝产生的措施。为类似工程提供有益的借鉴。     

夏季水泥混凝土施工质量问题分析

结合中国北方地区夏季气候特点,分析高温条件下新浇筑的混凝土可能出现的质量问题,多角度深入探讨质量问题产生原因及避免高温对混凝土质量影响可采取的主要措施,可为同类工程提供参考借鉴.     

夏季施工中水泥混凝土路面早期裂缝的成因与防治

结合混凝土夏季施工的特点,从内因和外因两方面分析了混凝土路面早期裂缝的成因,并提出了相应的防治措施,对实践具有一定的指导意义。     

夏热冬冷地区重交通钢桥面铺装技术应用

夏热冬冷地区重交通钢桥面铺装对钢板防护、混合料高温稳定性和低温抗裂性要求较高,同时需兼顾沥青混合料的耐久性和施工和易性。通过对全国典型钢桥面铺装的调研和分析,判断沙尔沁互通立交钢桥面浇注式沥青混凝土铺装设计的合理性,通过关键施工控制措施,使该种铺装结构在沙尔沁互通立交顺利实施。