海泡石持久脱除空气中微量甲醛的方法与机理     

梁凯  彭美勋  赵宏伟  罗莹华 《岩石矿物学杂志》2022,41(5):959-964

为克服海泡石吸附甲醛达到饱和后失去吸附功能的缺陷,利用静态吸附实验研究热处理温度对海泡石吸附微量甲醛的影响,并运用扫描电镜、X射线衍射、红外吸收光谱、热重和BET比表面检测等方法研究相关机理。结果表明,硅胶干燥剂的存在明显提高了海泡石对空气中微量甲醛的吸附能力,并能降低甲醛含量至法定安全上限以下,在≤400℃的温度热处理后海泡石仍能保持良好的甲醛吸附性能,但经≥500℃热处理后甲醛吸附性能显著降低。结合表征研究,认为海泡石相的结晶水对甲醛形成化学吸附,而其以沸石孔洞为主的结构微孔有利于物理吸附的甲醛占位,≥450℃的热处理使结晶水不可逆脱出,沸石孔坍塌,从而吸附性能显著降低。该研究表明海泡石的吸附性能可以在低于450℃的温度下热再生,脱出的甲醛也可以通过燃烧消除。间歇性热再生海泡石的吸附性能可持续脱除空气中的微量甲醛。  相似文献   

资源再生型地区资源环境承载能力评价指标体系构建——以河南省洛宁县为例     

李稳  宫少军  梁昊  王国槐  王培培 《中国地质调查》2021,8(3):81-89

为构建资源再生型地区资源环境承载能力评价指标体系,以河南省洛宁县为例,通过开展1:5万环境地质调查与地质环境背景资料收集,查明了该区资源环境禀赋条件和短板要素,并在地质环境承载能力、地下水资源承载能力和矿产资源承载能力评价的基础上,引入了矿山地质环境承载能力评价,创新性地构建了一套适用于资源再生型地区的资源环境承载能力评价指标体系。在完成实际验证评价的基础上,与通用资源环境承载能力评价指标体系进行了对比分析,结果发现,矿山地质环境承载能力评价结果与地质环境承载能力评价结果并不完全一致,且与矿产资源承载能力评价结果也有一定差异。研究表明,构建的资源再生型地区资源环境承载能力评价指标体系更适宜此类地区矿区分散分布且发展方式迥异的特点,能进一步突出地域主导特色,可为同类地区地质环境保护及资源开发规划提供参考。  相似文献   

Close coupling between ammonium uptake by phytoplankton and excretion by Antarctic krill, Euphausia superba     

M.J. WhitehouseA. Atkinson  A.P. Rees 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(7):725-732

In this study we examined the hypothesis that, under conditions of replete macronutrients and iron in the Southern Ocean, phytoplankton abundance and specific N uptake rates are influenced strongly by the processes of grazing and NH₄ regeneration. NH₄ and NO₃ uptake rates by marine phytoplankton were measured to the northeast and northwest of the island of South Georgia during January-February 1998. Mean specific uptake rate for NO₃ (vNO₃) was 0.0026 h⁻¹ (range 0.0013-0.0065 h⁻¹) and for NH₄ (vNH₄) was 0.0097 h⁻¹ (0.0014-0.0376 h⁻¹). vNH₄ was related positively with NH₄ availability, which ranged from 0.1 to 1.5 mmol m⁻³ within the upper mixed layer. Ambient NH₄ concentrations and vNH₄ were both positively related to local krill biomass values, computed from mean values along acoustic transect segments within 2 km of the uptake measurement stations. These biomass values ranged from ∼1 g krill fresh mass m⁻² in the northwest to >4 kg krill wet mass m⁻² in the northeast. In contrast to the variability found with NH₄ concentrations and uptake rates, vNO₃ was more uniform across the sampling sites. Under these conditions, increasing NH₄ concentration appeared to represent an additional N resource. However, high vNH₄ tended to be found for stations with lower phytoplankton standing stocks, across a total range of 0.24-20 mg chlorophyll a m⁻³. These patterns suggest a coupling between phytoplankton biomass, vNH₄ and krill in this region of variable but high krill biomass. Locally high concentrations of krill in parts of the study area appeared to have two opposing effects. On the one hand they could graze down phytoplankton stocks, but on the other hand, their NH₄ excretion supported enhanced uptake rates by the remaining, ungrazed cells.  相似文献   

城市更新之研究   总被引：7，自引：2，他引：5  

严若谷  周素红  闫小培 《地理科学进展》2011,30(8):947-955

城市更新是城市发展到一定阶段所必然经历的再开发过程,不同的时代背景和地域环境中的城市更新具有不同的动因机制、开发模式、权力关系,进而产生不同的经济、环境、社会效应。追溯近年来英文文献中大量出现的有关＂urban regeneration＂的研究及中国近30年来城市更新相关文献,总结地理学视角对城市更新的研究范围、研究领域及研究特点,论述与城市更新相关的理论,阐述城市更新的形成机制,分析各地区在不同阶段采用的更新政策,更新模式,更新手段和方法,以及更新参与主体和更新后的效果,对比分析国内外城市更新研究内容及特点。从城市更新同城市建设、经济发展的内在联系机制,城市更新中微观个体的行为研究,可持续发展观下的综合城市更新研究等3个方面,总结对未来中国城市更新发展的可借鉴性启示。  相似文献   

不同更新方式对中亚热带森林土壤理化性质的影响     

邓旺灶 《亚热带资源与环境学报》2011,6(3):18-23

森林的不同更新方式对森林土壤理化性质有重要影响．本研究通过野外调查探讨中亚热带山区杉木人工林和米槠人促更新林2种不同更新方式下林地土壤理化性质的变化特征,并用土壤退化指数定量描述土壤质量变化．结果表明：杉木人工林土壤表层（0—10cm）容重显著高于米槠人促更新林（P〈0．05）;随土壤深度的增加,杉木人工林和米槠人促更...  相似文献   

Concentration and Regeneration of Cd in the Japan Sea Proper Water     

Kazuo?AbeEmail author 《Journal of Oceanography》2005,61(3):455-463

The concentration level of cadmium (Cd) and the regeneration related to phosphate (PO₄) were examined at two stations (CM10, CM12) in the eastern Japan Basin in July 1998. The observed Cd concentrations were around 0.2–0.3 nM and 0.5–0.6 nM in the surface and deep layers (Japan Sea Proper Water; JSPW), respectively; the concentration of Cd in the JSPW was much lower than that in the Pacific deep water, which is attributed to its specific formation system (which driven by the winter convection of the surface layer within the Japan Sea, thereafter descending to the deep layer) connected with the relatively active vertical mixing in the Japan Sea. A plot of Cd against PO₄ showed good linearity with positive y-intercept values, suggesting that the excess Cd was apparently not available in the biogeochemical cycle. The molecular ratios of consumed O₂ to regenerated Cd and PO₄ in the JSPW were 688,000, 140 and 881,000, 146 for CM10 and CM12, respectively, and a lower preformed Cd concentration (around 0.37 nM) was also estimated in the JSPW, different from that of the North Pacific deep water (613,000 for Cd, 170 for PO₄, and 0.64 nM of preformed Cd).  相似文献   

Coral Recruitment and Regeneration on a Maldivian Reef Four Years after the Coral Bleaching Event of 1998. Part 2: 2001–2002     

Karen Loch  Wolfgang Loch  Helmut Schuhmacher  & Wolf R. See 《Marine Ecology》2004,25(2):145-154

Abstract.  This paper is the follow-up study to a quantitative inventory of stony corals on a Maldivian reef after the bleaching event of 1998 [Loch, K., W. Loch, H. Schuhmacher & W. R. See, 2002; P.S.Z.N.: Marine Ecology, 23 (3): 219–236] covering the years 2001 and 2002, thereby extending the observation period from 1999 to 2002. Data collection was performed as previously in transects on the reef flat, Acropora tables at the reef rim, Porites lobata blocks and one Diploastrea heliopora colony. While between 2000 and 2001 the transects showed a noticeable increase of living scleractinian colonies of 6.1 per m² of reef surface per year, this had slowed to 0.7 per m² per year by 2002. Likewise, the colonisation of dead Acropora tables had changed from a yearly increase of 14.4 colonies per m² of table surface between 2000 and 2001 to a decrease of 9.4 between 2001 and 2002. The main constituent of the regeneration in transects as well as on Acropora tables was Pavona (Agariciidae), whereas Pocilloporidae and Acroporidae were almost completely missing. A new immigrant was Tubastraea micranthus . Continuous growth of regenerates on Porites presented a columnar form, and the growth rate of D. heliopora was reduced between 2001 and 2002. The influence on reef ecology in terms of coral substrate, species differentiation, growth rate changes, interaction with other organisms and the overall prospect of the reef development on a longer timescale is outlined.  相似文献   

孔石莼外植体再生及发育途径的研究     

邵魁双  王金霞  周百成 《海洋科学》2004,28(6):46-50

将孔石莼 (UlvapertusaKjellm)野生种和“不育株”突变体的叶状体切成1cm2 以下大小不同的片段培养 ,发现再生情况和外植体大小存在密切关系。在5mm×5mm以下的片段中 ,90%以上的细胞都出现了再生 ,表现为3种发育途径 :形成球形的原生质体 ,经丝状体而成叶状体 ;产生游动细胞 ,也经过丝状体而成叶状体 ;细胞原位分裂 ,形成球状体或管状体 ,呈现礁膜属和浒苔属的特征。5mm×5mm～10mm×10mm的片段 ,除边缘的1～2层中有极少量细胞形成游动细胞和球形原生质体外 ,其它细胞没有变化。将由片段再生形成的小叶状体采到紫菜苗网上 ,经过一年的海区养殖 ,长成1m长的叶状体  相似文献   

罗氏海盘车腕再生过程的组织学研究     

樊廷俊  杜玉堂  丛日山  孙文杰  汤志宏  袁文鹏  石莹  耿晓芬  李明玉 《中国海洋大学学报(自然科学版)》2005,35(4):559-563

对海盘车腕再生过程的研究，对于早日揭示棘皮动物等后口动物的再生机理具有重要意义。为了查清棘皮动物的再生方式及其机理，文中利用断腕创伤手术、组织化学和细胞化学技术对罗氏海盘车腕的再生过程进行了研究。连续跟踪研究结果表明，创伤8d后，在罗氏海盘车创伤腕的外表皮层和体腔上皮中均出现了干细胞原基样结构(blastema-like structure)。创伤腕的伤口愈合过程是1个多事件同期发生的综合过程，首先是真皮层中脱分化的肌肉样细胞向创伤处迁移和聚集，经再分化和组织重排逐渐形成成熟的真皮层组织，然后是外表皮层和体腔上皮中的脱分化细胞向创伤处迁移分别形成明显加厚的前表皮层和前体腔上皮，最后再分别分化为成熟的表皮层和体腔上皮。而海盘车腕的再生过程则包括新生腕芽的延长和残腕的延长2个事件同期发生的过程。新生腕芽的生长与延长是在创伤愈合的基础上，依靠表皮层、体腔上皮和真皮层来源的脱分化细胞的迁移和再分化先形成新生腕芽，随后在新生腕芽上又出现了新的干细胞原基样结构，使腕芽逐渐生长和延长。而创伤刺激下残腕的延长，则是在形成干细胞原基样结构的基础上，在残腔体壁的许多部位形成多个横跨体壁的“楔状”干细胞原基样结构，这些结构的多点插入及其再分化形成新的体壁组织使残腕得以延长。本文的研究结果还显示，罗氏海盘车腕的再生同时采用了表变态再生和变形再生2种方式。  相似文献   

Iron regeneration and organic iron(III)-binding ligand production during in situ zooplankton grazing experiment     

Mitsuhide Sato  Shigenobu Takeda  Ken Furuya 《Marine Chemistry》2007,106(3-4):471-488

To elucidate iron regeneration and organic iron(III)-binding ligand formation during microzooplankton and copepod grazing on phytoplankton, incubation experiments were conducted in the western subarctic Pacific. During 8 days of dark incubation of ambient water and that amended with plankton concentrate, dissolved iron and organic iron(III)-binding ligands accumulated, approximately proportionally to the decrease in chlorophyll a. The observed increases in dissolved iron concentration were much greater than those expected from the consumption of phytoplankton biomass and previously reported Fe:C value of cultured algal cells, suggesting resolution from colloidal or particulate iron adsorbed onto the algal cell surface. When copepods were added to the ambient water, organic iron(III)-binding ligands accumulated more rapidly than in the control receiving no copepod addition, although consumed phytoplankton biomass was comparable between the two treatments. Bioassay experiment using filtrates collected from the incubation experiment showed that organic ligands formed during microzooplankton grazing reduced the iron bioavailability to phytoplankton and suppressed their growth. Moreover, picoplankton Synechococcus sp. and Micromonas pusilla were more suppressed by the organic ligands than the diatom Thalassiosira weissflogii. In conclusion, through microzooplankton and copepod grazing on phytoplankton, organic iron(III)-binding ligands as well as regenerated iron are released into the ambient seawater. Because the ligands lower iron bioavailability to phytoplankton through complexation and the degree of availability reduction varies among phytoplankton species, grazing by zooplankton can shift phytoplankton community structure in iron-limited waters.  相似文献