两次秸秆焚烧污染过程的气象条件对比分析   总被引：1，自引：1，他引：0  

毛宇清  李聪  沈澄  刘冬晴  王永平 《气象》2013,39(11):1473-1480

利用常规气象资料、卫星遥感监测资料、污染物浓度资料和NECP/NCAR再分析资料,结合气流后向轨迹模拟,对比分析了南京地区2011年6月10和13日两次由于秸秆焚烧而引起的严重空气污染事件的天气条件、大气边界层特征以及污染物的来源和输送路径等。结果表明：两次污染过程中PM2.5浓度均出现陡升陡降,由秸秆焚烧而产生的细粒子贡献显著。13日高污染的持续时间和强度都高于10日,10日的高低空形势配置和物理量场有利于降水的产生,对污染物有一定的冲刷作用,而13日的高低空形势配置和物理量场则有利于污染物在边界层堆积。两次污染过程的边界层逆温均不明显。气流后向轨迹模拟表明,两次过程都是由区域污染输送造成的,都主要来源于苏中、苏北地区,13日的污染源可能还有苏南和安徽地区。  相似文献   

Preparation of strontium ferrite from strontium residue   总被引：1，自引：0，他引：1  

Chenglun Liu  Longjun Xu  Xueyan Yang  Tiefeng Peng  Jianjun Ren 《中国地球化学学报》2012,31(1):74-77

Strontium ferrite was prepared from Strontium Waste Residue (SWR) as a material. Strontium chloride was obtained by leaching SWR with ammonia chloride, and then SrCl2 was converted to SrCO3. Strontium ferrite (SrFe12O19) was formed by roasting the mixture of SrCO3 and FeCl3 in a proper proportion. The structure and magnetic susceptibility of strontium ferrite were investi-gated. The results showed that strontium conversion ratio increased with decreasing SWR grain diameter. The largest ratio was pre-sented when n(NH4Cl/Sr) was 3.6. What is more, the conversion process coincided with the kinetic characteristics of fractal reaction. The magnetic susceptibility of strontium ferrite decreased with increasing Fe3+/Sr2+ mole ratio and pH. SrFe12O19 exhibited face-centered and cubic closely-packed hexagonal structures. There were the strong diffraction peaks of Fe2O3 in the X-ray diffracto-gram of strontium ferrite. Strontium recovery ratio was 87.0%.  相似文献   

Quantification of Diclofenac in Hospital Effluent and Identification of Metabolites and Degradation Products     

Luciane Minetto  Francieli M. Mayer  Carlos A. Mallmann  Ayrton F. Martins 《洁净——土壤、空气、水》2012,40(9):950-957

In this study the occurrence of diclofenac and sub‐products in effluent emerging from the University Hospital at the Federal University of Santa Maria was investigated. One metabolite was identified and, in aqueous solution, three degradation products. The quantification was conducted by means of HPLC‐DAD, and the determination of metabolite and degradation products by LC–ESI–MS/MS–QTrap. For the HPLC‐DAD method, a 70:30 mixture of methanol/sodium phosphate was used in isocratic mode. For the LC–ESI–MS/MS–QTrap determinations, a mobile phase, where phase A was an ammonium acetate solution 5 × 10^?3 mol L^?1, and phase B was methanol (5 × 10^?3 mol L^?1)/ammonium acetate (9:1, v/v), on gradient mode. The LDs for the HPLC and LC–MS/MS methods, respectively, were 2.5 and 0.02 µg L^?1, the LQs, 8.3 and 0.05 µg L^?1, and the linear range from 10 up to 2000 µg L^?1 and 0.05 up to 10 µg L^?1. As expected, the LC–ESI–MS/MS–QTrap method was more sensitive and less laborious. The metabolite 4′‐hydroxy‐diclofenac was identified. Photolysis was used for the degradation studies and three products of diclofenac were identified (m/z of 214, 286 and 303) in aqueous solution. These results notwithstanding, no degradation products of diclofenac were found in the hospital effluent.  相似文献   

碱渣改良膨胀土室内试验研究   总被引：10，自引：0，他引：10  

孙树林  郑青海  唐俊  张淦钰  周立国  尚文涛 《岩土力学》2012,33(6):1608-1612

通过室内试验,探讨利用碱渣作为添加剂对膨胀土改良的可行性和改良效果和碱渣改性土的基本物理力学性质和膨胀性。研究结果表明,随着掺渣率的增加,碱渣改性土的黏性成分的含量降低,粗颗粒含量增加,导致相对密度、液限、塑性指数、自由膨胀率、有荷膨胀量均呈明显减小趋势,这说明碱渣对膨胀土膨胀性的改良有显著效果;碱渣改性土可击实含水率范围较之膨胀土宽,这给碱渣改性土的施工带来很大方便;经过7 d养护后的土样无侧限抗压强度和抗剪强度都显著增加,并在掺渣率为30%时存在一个峰值点。抗剪强度增强主要体现在黏聚力显著增加,而内摩擦角变化不大。  相似文献   

Water Purification Using Cost Effective Material Prepared from Agricultural Waste: Kinetics,Isotherms, and Thermodynamic Studies          下载免费PDF全文

Mu. Naushad  Mohammad Rizwan Khan  Zeid Abdullah ALOthman  Ala'a H. Al‐Muhtaseb  Md. Rabiul Awual  Ayoub Abdullah Alqadami 《洁净——土壤、空气、水》2016,44(8):1036-1045

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Responses in growth, lipid accumulation, and fatty acid composition of four oleaginous microalgae to different nitrogen sources and concentrations   总被引：1，自引：0，他引：1  

李涛  万凌琳  李爱芬  张成武 《中国海洋湖沼学报》2013,31(6):1306-1314

Nitrogen deficiency is an effective strategy for enhancing lipid production in microalgae. Close relationships exist among lipid production, microalgal species, and nitrogen sources. We report growth, lipid accumulation, and fatty acid composition in four microalgae （Chloroeoccum ellipsoideum UTEX972, Chlorococcum nivale LB2225, Chlorococcum tatrense UTEX2227, and Scenedesmus deserticola JNU19） under nitrate- and urea-nitrogen deficiencies. We found three patterns of response to nitrogen deficiency： Type-A （decrease in biomass and increase in lipid content）, Type-B （reduction in both biomass and lipid content）, and Type-C （enhancement of both biomass and lipid content）. Type-C microalgae are potential candidates for large-scale oil production. Chlorococcum ellipsoideum, for example, exhibited a neutral lipid production of up to 239.6 mg/（L＇d） under urea-nitrogen deficiency. In addition, nitrogen deficiency showed only a slight influence on lipid fractions and fatty acid composition. Our study provides useful information for further screening hyper-lipid microalgal strains for biofuel production.  相似文献   

CORNELL DESIGN APPLIED ON OPTIMAL MACRONUTRIENT COMPOSITION OF FORMULATED DIETS FOR DAVID＇S SCHIZOTHORACIN [SCHIZOTHORAX （RACOMA） DAVID1] JUVENILES     

《海洋与湖沼》2012,43(4)

采用Comell方法研究了初始重为（2．0±0．1）g的重口裂腹鱼幼鱼日粮中常量营养物质的适宜需求量。日粮中蛋白质、脂肪和碳水化合物梯度变化范围分别为33％-51％、3％-18％和24％-33％,试验周期为60d。试验结果表明,除日粮蛋白质33％组鱼成活率明显下降外（P〈0．05）,其它试验日粮中3种常量营养物质含量对重口裂腹鱼幼鱼成活率没有显著影响（P〉0．05）。当日粮蛋白质水平≤45％时,其特定生长率随着日粮蛋白质水平上升而明显增加;当日粮蛋白质水平在33％-36％时,重口裂腹鱼的特定生长率显著降低（P〈0．05）。除12％日粮脂肪组试验鱼外,9％日粮脂肪组试验鱼的特定生长率显著性高于其它脂肪水平日粮组（P〈0．05）,但当日粮中脂肪含量≥15％后,重口裂腹鱼鱼体脂肪含量显著上升（P〈0．05）,肝细胞脂肪变性明显。日粮中不同的碳水化合物水平对重口裂腹鱼特定生长率没有显著影响（P〉0．05）,但当日粮中碳水化合物为33％时,鱼体糖原含量显著增加（P〈0．05）。试验表明,重口裂腹鱼幼鱼日粮蛋白质、脂肪和碳水化合物3种常量营养物质的适宜需求量分别为45％、9％和≤30％。日粮总能为19．0MJ／kg,蛋白质能量比（P／E）为23mg／J。  相似文献   

海带渣资源化利用及在小球藻培养中的应用研究     

王铭  彭敏琳  许瑾  梁翠谊  向文洲  李涛 《海洋与湖沼》2022,53(1):96-105

海带渣是海带加工中的固体废弃物,将其资源化利用生产高附加值产品具有重要意义.文章以海带渣为原料,糖化液的总还原糖质量浓度、单糖组成和小球藻培养效果为主要评估指标,探究不同预处理方法对海带渣酶解的影响,以及海带渣资源化利用培养微藻工艺的可行性.结果 显示:(1)粗纤维和灰分是海带渣主要组成成分;(2)常温常压稀硫酸预处理...  相似文献   

Nutritional condition of fish larvae in South African estuaries: an appraisal of three biochemical methods     

《African Journal of Marine Science》2013,35(3):377-386

Estuaries are exposed to a number of threats and many South African estuarine systems are functionally and structurally altered. The extent to which fish are affected by these alterations is not fully understood. The estuarine round herring Gilchristella aestuaria is an appropriate species to use when examining such effects. The most widely used approaches to evaluating the nutritional condition of fish larvae are based on biochemical methods. In order to identify the most suitable technique for assessing body condition of fish larvae in estuaries, the nutritional condition of post-flexion larvae of G. aestuaria from the Sundays and Kariega estuaries on the south-east coast of South Africa was evaluated using three different biochemical techniques: (i) total lipid content analysis and the triacylglycerol/cholesterol (TAG/CHOL) ratio; (ii) protein content analysis; and (iii) the RNA/DNA ratio. Results from techniques (ii) and (iii) revealed that G. aestuaria larvae from the Kariega Estuary were in better condition than larvae from the Sundays Estuary, probably due to a recent plankton bloom. It is concluded that the individual RNA/DNA ratio can provide a reliable, sensitive and cost-effective method to assess the immediate effects of environmental changes on the nutritional condition of estuarine fish larvae.  相似文献   

Crop Residue Ashes as Adsorbents for Basic Dye (Methylene Blue) Removal: Adsorption Kinetics and Dynamics          下载免费PDF全文

Rakesh Kumar Ghosh  D. Damodar Reddy 《洁净——土壤、空气、水》2014,42(8):1098-1105

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