氚水照射妊娠大鼠对其仔鼠游泳机能及大脑重量发育的影响

本文报道了氚水(HTO)照射妊娠大鼠对其仔鼠游泳机能及大脑重量发育影响的研究。实验是在21只雌性大鼠及其所产的237只仔鼠身上进行的。研究结果表明,大白鼠从妊娠第8d 至分娩后21d 连续接受放射性浓度为0.185MBq/ml(5μCi/ml)和0.740MBq/ml(20μCi/ml)的体水·氚照射,在15—33d 内接受总剂量为0.195—1.848Gy,可使18d 龄以前仔鼠游泳机能发育受阻。     

荷包场-界市场地区嘉二段海滩岩相及其与油气关系

荷包场-界市场地区下三叠统嘉陵江组嘉二段气藏的主要储集岩为针孔白云岩,属海滩岩相。它处于低能环境海进序列的开始。储集空间为粒内、粒间溶孔及晶孔,是早期成岩过程中淡水淋滤和白云岩化作用的产物。储集岩的分布严格地受海进、海退和古高地控制。     

商品专卖型企业门户网站建设的模式研究

商品专卖企业是在商品专卖制度管理下的一类特殊的企业,这类企业的管理信息系统的建设也必须遵循专门的管理制度,而其门户网站又是管理信息系统的主要工作平台。如何规划和建设这类门户网站的建设?作者以某企业门户网站的实际范例对这个问题做了一些简要的探讨。     

“一带一路”与中国对外油气战略的调整（增刊）

“一带一路”战略必将引起区域经济结构包括国家能源战略的调整。现阶段逐步完成油气产业从中东地区向中亚油气中心的倾斜、转移和布局调整,逐步调整和实现“加强中亚、稳定中东、争夺非洲、开拓其它” 的中国油气对外合作战略,实现.3.5亿吨的海外份额油和采购油目标。加强在中亚等地区的陆路油气管网投入,推动能源装备制造及能源服务企业“走出去”与中亚诸国开展多层次、全产业链的深度合作。建设炼油化工基地,技术研发基地、装备制造基地;加强油气管网的互联互通建设,建立和完善中亚石油天然气交易中心,强化上合组织框架内的经贸合作、文化融合、司法认知等往来交流。     

新形势下中国与中亚油气合作面临的挑战和前景展望（增刊）

中亚地区油气资源丰富,中国与中亚国家的油气合作已近20年,合作成果丰硕。在油价持续低迷的情况下,中亚国家对能源策略和油气政策做出了相应调整。新形势下,中国与中亚油气合作面临着地缘政治形势更加复杂、大国博弈和竞争激烈、合作思路需要调整等多重挑战。在“一带一路”战略背景下,我国要全面推进与中亚国家的油气合作,并在此基础上进一步推动能源综合发展,实现与中亚国家的协同发展。     

城市更新概念下的棕地转变为绿地

简要回顾了棕地的背景和概念,以及其改造利用的主要原则。在当代城市更新的背景下,将棕地改造为绿地成了可持续利用土地的重要途径之一。分别以柏林萨基兰德自然公园和巴塞罗那泊布诺公园为例,讨论了在不同的城市更新条件下棕地转化为绿地的工作框架。     

Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California's Central Valley

We examined methylmercury (MeHg) bioavailability in four of the most predominant wetland habitats in California's Central Valley agricultural region during the spring and summer: white rice, wild rice, permanent wetlands, and shallowly-flooded fallow fields. We sampled MeHg and total mercury (THg) concentrations in two aquatic macroinvertebrate taxa at the inlets, centers, and outlets of four replicated wetland habitats (8 wetlands total) during two time periods bounding the rice growing season and corresponding to flood-up and pre-harvest (96 total samples). In general, THg concentrations (mean ± standard error) in Notonectidae (Notonecta, back swimmers; 1.18 ± 0.08 µg g^− 1 dry weight [dw]) were higher than in Corixidae (Corisella, water boatmen; 0.89 ± 0.06 µg g^− 1 dw, MeHg: 0.74 ± 0.05 µg g^− 1 dw). MeHg concentrations were correlated with THg concentrations in Corixidae (R² = 0.80) and 88% of THg was in the MeHg form. Wetland habitat type had an important influence on THg concentrations in aquatic invertebrates, but this effect depended on the sampling time period and taxa. In particular, THg concentrations in Notonectidae, but not Corixidae, were higher in permanent wetlands than in white rice, wild rice, or shallowly-flooded fallow fields. THg concentrations in Notonectidae were higher at the end of the rice growing season than near the time of flood-up, whereas THg concentrations in Corixidae did not differ between time periods. The effect of wetland habitat type was more prevalent near the end of the rice growing season, when Notonectidae THg concentrations were highest in permanent wetlands. Additionally, invertebrate THg concentrations were higher at water outlets than at inlets of wetlands. Our results indicate that although invertebrate THg concentrations increased from the time of flood-up to draw-down of wetlands, temporarily flooded habitats such as white rice, wild rice, and shallowly-flooded fallow fields did not have higher THg or MeHg concentrations in invertebrates than permanent wetlands.     

浅谈变频器在中央空调系统节能改造中的运用

随着中国经济的快速发展,中央空调系统已在社会广泛应用,在为人们提供舒适的工作和生活环境的同时,中央空调系统也成为建筑的能耗大户。在全球推进低碳经济,节能减排的大趋势下,如何节能、高效地解决中央空调系统的节能减排问题,已经成为社会研究的热点。据国家能源局统计,我国建筑能耗约占全国总能耗的30%左右,而空调能耗又约占建筑总能耗的50%~65%,降低空调系统能耗对我国完成节能减排目标与推动建设为节约型社会具有非常重要的作用。