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41.
实验对恒液位SBR工艺脱氮除磷进行了研究。结果表明,交替缺氧/好氧段,可以有效的实现硝化反硝化脱氮和好氧摄磷,缺氧时,进水补充的碳源及时满足了反硝化的需求,系统同时还存在同步硝化反硝化作用。厌氧段,溶解氧快速降至0mg/L在进水补充的碳源条件下释磷充分,从而保证后期摄磷完全,整体高效脱氮除磷。  相似文献   
42.
Abstract

This article discusses holistic well-being in a balanced work system theory framework. Holistic well-being is a combination of well-being in both work and non-work domains. Theories of balanced work systems and balanced organisations are retold in light of holistic well-being to show how different individuals in organisations can contribute to achieving desired outcomes at different process levels. Further, this article provides new insights and research challenges to the balanced organisation theory by including a sustainability aspect and by proposing a new concept of balanced value networks.  相似文献   
43.
对广东省罗定市泗纶镇沙罗竹人工林生长与地形因子和土壤理化性质之间的关系进行了分析研究。结果表明,地形部位、坡型、坡向、土壤质地、立竹密度等对沙罗竹平均胸径有显著影响;沙罗竹平均胸径与土壤水分、有机质、全氮、速效氮、速效磷、有效硅质量分数呈显著正相关关系。回归分析结果表明,土壤有机质、速效氮、速效磷、有效镁质量分数及其组合是影响沙罗竹生长的主要养分因子。研究结果对沙罗竹林地选择和制定营林管理措施具有科学指导意义。  相似文献   
44.
环境中铅的化学循环   总被引:4,自引:0,他引:4  
本文论述了环境中铅的背景值、来源、污染、质量标准,化学循环包括沉淀溶解、络合解离和吸附解吸以及环境中铅的烷基化,为铅污染治理提供理论依据.  相似文献   
45.
全面安全管理-6 Sigma方法论   总被引:2,自引:0,他引:2  
概述了最新全面管理工具 6Sigma方法论的概念、原理 ,以及 6Sigma持续循环的 5个阶段在现代企业全面安全管理中的应用  相似文献   
46.
An optimized code for the near real-time retrieval of line of sight, temperature and volume-mixing ratio profiles of five key species (O3, H2O, HNO3, CH4 and N2O) from infrared limb spectra recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) experiment on board the ENVISAT-1 satellite was developed as part of an ESA-supported study. In this code line of sight and temperature are retrieved simultaneously among themselves, but sequentially with respect to the volume-mixing ratio of the five key species. The sequential retrieval leaves unaccounted the mapping of line of sight and temperature errors in the retrieved volume-mixing ratio of the constituents. This paper illustrates an algorithm that provides the a-posteriori evaluation of temperature and line-of-sight-induced error on the retrieved volume-mixing ratio of the MIPAS key species. It is shown that in most cases temperature and line-of-sight-induced error provides a significant contribution to the total volume-mixing ratio error. The variability of this error as a function of latitude, season and atmospheric model is also analyzed.  相似文献   
47.
云南粳稻核心种质杂种后代孕穗期耐冷性研究   总被引:1,自引:1,他引:0  
以236份云南地方粳稻核心种质和云南主栽梗稻Oryza satica品种合系35配制的杂种F5、BC1F4、BC2F3和BC3F2为材料,在昆明自然低温平均17.8℃(冷害)条件下,对亲本及其后代进行孕穗期耐冷性研究.结果表明:①亲本耐冷性状间的相关性明显高于其杂种后代,不同世代间总体趋势为随着回交世代增加其性状间相关性减弱.在亲本及其杂种后代间耐冷指标性状穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率均呈较高的(≥0.370)极显著(n=236,R0.01=0.181)相关.②株高、穗颈长、穗下节长等耐冷性状在亲本强弱耐冷系统群间的差异明显,表现为亲本耐冷性强的材料秆和穗较长、穗粒数较多,同一性状变异程度减小.但随着回交代数的增加,这些性状的平均值逐渐趋同于轮回亲本,差异减小.③穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率在5个稻作区间的变化规律呈现一致性,亲本和F5的差异较大,而BC2F4、BC2F3和BC3F2的差异较小,且趋同于轮回亲本.通过连续回交,在BC3F1即可获得耐冷性状表现良好的材料.  相似文献   
48.
微波消解/ICP-AES法测定土壤中的环境有效态金属元素   总被引:10,自引:0,他引:10  
陈丰  刘芳 《上海环境科学》2003,22(12):967-970
传统的土壤样品消解技术手续繁琐、费时,成为整个分析过程的薄弱环节;微波消解很好地解决了这一问题。采用微波消解技术处理土壤样品,以ICP-AES法测定Ag、As、Ba.Be、Cu、Mn、Mo、Ni、Pb、Sr、V、Zn,Al、Co 14种环境有效态金属元素。选择了HNO_3-HCL-H_20_2消解体系,确定了最佳微波消解功率和时间。方法精密度以相对标准偏差表示为1.20%~6.13%,准确度以回收率表示为79.6%~97.4%,与传统的酸解法处理样品相比较,相对误差在±120%以下,结果基本一致。微波消解处理土壤样品比传统的酸解法节省了约10倍的时间,具有快速、高效、清洁、用量少、背景值小等优点。  相似文献   
49.
羊草和大针茅光合作用午间降低与生态因子关系的研究   总被引:20,自引:0,他引:20  
本项研究指出,在晴天条件下,由于土壤水分含量不同,羊草和大针茅的光合作用日进程呈现出两种类型:在土壤水分充足时,为午前高峰型;在土壤干旱时,为双峰型。两者均属于光合作用午间降低的类型。 两种植物相比,在土壤干旱时,羊草比大针茅光合午间降低幅度大得多;在土壤水分充足时,其降低程度相近。无论土壤含水量高低,大气湿度降低均是引起光合午间降低的主要大气生态因子。所不同的是,强光只有在土壤干旱时才是引起光合午间降低的直接生态因子;因此,午后光合高峰的出现是光强下降所致。土壤水分亏缺与大气低湿相配合,加剧了光合午间降低的程度,其降低幅度随着土壤水分的减少而增大。因此,增加土壤水分是减缓光合午间降低程度的主要生态途径。  相似文献   
50.
Sampling and physico-chemical analysis of precipitation: a review   总被引:2,自引:0,他引:2  
Wet deposition is one of two processes governing the transfer of beneficial and toxic chemicals from the atmosphere on to surfaces. Since the early 1970s, numerous investigators have sampled and analyzed precipitation for their chemical constituents, in the context of "acidic rain" and related atmospheric processes. Since then, significant advances have been made in our understanding of how to sample rain, cloud and fog water to preserve their physico-chemical integrity prior to analyses. Since the 1970s large-scale precipitation sampling networks have been in operation to broadly address regional and multi-regional issues. However, in examining the results from such efforts at a site-specific level, concerns have been raised about the accuracy and precision of the information gathered. There is mounting evidence to demonstrate the instability of precipitation samples (e.g. with N species) that have been subjected to prolonged ambient or field conditions. At the present time precipitation sampling procedures allow unrefrigerated or refrigerated collection of wet deposition from individual events, sequential fractions within events, in situ continuous chemical analyses in the field and even sampling of single or individual rain, cloud and fog droplets. Similarly analytical procedures of precipitation composition have advanced from time-consuming methods to rapid and simultaneous analyses of major anions and cations, from bulk samples to single droplets. For example, analytical techniques have evolved from colorimetry to ion chromatography to capillary electrophoresis. Overall, these advances allow a better understanding of heterogeneous reactions and atmospheric pollutant scavenging processes by precipitation. In addition, from an environmental perspective, these advances allow better quantification of semi-labile (e.g. NH4+, frequently its deposition values are underestimated) or labile species [e.g. S (IV)] in precipitation and measurements of toxic chemicals such as Hg and PCBs (polychlorinated biphenyls). Similarly, methods now exist for source-receptor studies, using for example, the characterization of reduced elemental states and/or the use of stable isotopes in precipitation as tracers. Future studies on the relationship between atmospheric deposition and environmental impacts must exploit these advances. This review provides a comprehensive and comparative treatment of the state of the art sampling methods of precipitation and its physico-chemical analysis.  相似文献   
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