2007年中国区域性酸雨的若干特征   总被引：24，自引：0，他引：24       下载免费PDF全文

侯青  赵艳霞 《气候变化研究进展》2009,5(1):7-11

 基于中国气象局1993-2007年的酸雨观测站资料, 着重分析了2007年中国区域酸雨的特征,并和近十几年来我国区域酸雨的变化特点进行对比。与过去十几年相比,2007年全国区域酸雨的特点如下：1) 我国位于长江以南的酸雨区范围基本保持不变,但南方部分站点的酸雨强度达近十几年来的最高值;2) 我国北方尤其是华北部分地区的降水酸化明显,部分省市站点的酸雨频率和强酸雨频率达近15 a来的最高值;3) 2003-2007年,全国年均酸雨日数和酸雨量与总降水量的比值逐年上升,且增幅较为明显。2007年全国平均酸雨日数为1993年有系统观测数据以来的最高值。  相似文献   

山西省2007年酸雨特征分析及成因初探   总被引：2，自引：0，他引：2  

李明明  卢淑贤  杨爱琴  岳江  王小兰  王海彦 《山西气象》2009,(2):24-27

本文利用五台山、大同、太原、长治、侯马5个酸雨观测站2007年1月～12月的酸雨观测资料,进行了分析,结果表明：五台山酸雨出现频率最高（85．96％）,大同酸雨频率最低（36．36％）;侯马站年降水pH值最低（4．09）,酸雨强度最强,大同的年降水pH值最高（5．36）,酸雨程度最弱;各站pH值最低值一般出现在秋、冬和春季,说明与采暖期燃煤有关。山西酸雨的成因主要与工业结构以及气象因素有关。  相似文献   

Methodology of analysis associating survey results by the filter-pack method with those of precipitation- Acid-base balance on acid-related and alkali-related chemical species in urban ambient air and its influence on the acidification of precipitation -     

Masahide Aikawa  Takatoshi Hiraki 《Journal of Atmospheric Chemistry》2008,61(1):21-29

Continuous weekly monitoring on the concentration of gases and aerosols in urban ambient air by a four-stage filter-pack method was carried out for 7 years in order to study not only the acid-base balance of acid-related (HNO₃, NO₃ ⁻, and non-sea-salt-(nss-)SO₄ ²⁻) and alkali-related (NH₃, NH₄ ⁺, and nss-Ca²⁺) chemical species but also its influence on the acidification of precipitation. The concentrations of the total nitrate (= NO₃⁻ + HNO₃) and nss-SO₄²⁻ showed a similar seasonal variation: high in the summer and low in the winter. The total nitrate and nss-SO₄²⁻ accounted for 0.43 and 0.57 of the acid-related species, respectively, on an equivalent basis. The total ammonium (= NH₃ + NH₄⁺) accounted for more than 0.9 of the alkali-related species, except for a springtime nss-Ca²⁺ episodic peak. The alkali-related species were generally overabundant compared with the acid-related species in the HNO₃-NO₃⁻-nss-SO₄²⁻-NH₃-NH₄⁺-nss-Ca²⁺ system. The alkali-rich distribution was especially pronounced in the winter, but the acid-related species was comparable to the alkali-related species in the summer, which was attributed to the larger H⁺ deposition by precipitation in the summer. This study can provide a methodology to associate survey results obtained by a filter-pack method with those of precipitation.  相似文献   

Relevance of ion-induced nucleation of sulfuric acid and water in the lower troposphere over the boreal forest at northern latitudes     

M. Boy  J. Kazil  E.R. Lovejoy  A. Guenther  M. Kulmala 《Atmospheric Research》2008,90(2-4):151-ICNAA07

The relevance of ion-induced nucleation of sulfuric acid and water (IINSW) in the troposphere over the boreal forest at northern latitudes is investigated by combining two existing and previously published models (MALTE — model to predict new aerosol formation in the lower troposphere; PARNUC — a parameterized steady-state model of neutral and ion-induced nucleation of sulfuric acid and water for atmospheric conditions). Simulations were performed for 4 days with observed new particle formation at ground level by using input data from the SMEAR II station in Hyytiälä, Finland. The selected days were chosen to cover a wide range of values of the parameters most relevant for IINSW. The results showed that ion-induced nucleation of sulfuric acid and water can contribute up to 15% to the total amount of newly formed particles in the size range of 3–10 nm inside the mixed layer at the Hyytiälä site. The importance of IINSW seemed to increase in the free troposphere above the boundary layer, however, lack of measurements in the vertical structure of the input parameters suggest that the model results are burdened with high uncertainties.  相似文献   

降水化学特性的一种分类分析方法   总被引：30，自引：1，他引：29  

程新金  黄美元 《气候与环境研究》1998,3(1):82-88

在分析比较不同地区降水化学特性时,如果列出各种离子的具体数值,既显得繁琐又不容易得出结论。现提出一种简便方法,即先概括出几种最重要的降水化学特性,分别以字母代表,再把这些特性分成几个等级以数字表示,就能很直观方便地比较这些地区的降水化学特性。还利用权威观测资料,以上述方法具体比较了世界主要酸雨地区的降水化学特性。  相似文献   

Effects of Nutritional Factors on the Growth and Heterotrophic Eicosapentaenoic Acid Production of Diatom Nitzschia laevis     

CAO Xiaohong  LI Songyao  WANG Chunling  LU Meifang 《中国海洋大学学报(英文版)》2008,7(3)

The effects of several nutritional factors on the growth and eicosapentaenoic acid (EPA) production of diatom Nitzschia laevis were studied. 4 LDM (quadrupled concentration of the nutrient salt) was the optimal concentration of nutrient salt for the growth and EPA production ofN. laevis. The growth ofN. laevis was inhibited when the glucose concentration was either lower than 10gL-1 or higher than 15gL-1. Both sodium nitrate and urea were good nitrogen sources for the growth and EPA production, while ammonium chloride seriously decreased the dry cell weight (DW) and the EPA content. Silicate seriously influenced the growth of N. laevis. The maximum DW of 2.34gL-1 was obtained in the presence of 150 mgL-1 Na2SiO3·9H2O. The EPA content remained almost the same when the silicate concentration was lower than 150 mgL-1; however, higher silicate concentrations resulted in a steady de- crease of EPA content. Low medium salinity (≤29) did not seem to influence the DW of N. laevis, and high salinity resulted in a decrease of DW. The highest EPA content (4.08%) and yield (110 mgL-1) were observed at the salinity of 36 and 29, respectively.  相似文献   

金佛寺岩体地球化学特征及成因     

胡能高  苏建平  张海峰  冯备战 《地球科学与环境学报》2006,28(1):5-12

金佛寺岩体是一个晚志留世侵入于北祁连造山带中的花岗质岩体,主要由黑云母二长花岗岩,黑云母钾长花岗岩和黑云母石英二长岩组成。岩体中岩石w(SiO2)为67.09%~74.97%,w(K2O)/w(Na2O)为1.18~1.83,w(MgO),w(TFeO),w(CaO)和w(Al2O3)随w(SiO2)增大而减小,而w(K2O)增大。ANCK为1.06~1.24,均属铝过饱和,σ为1.25~2.48,属钙碱性系列。ΣREE为(21.36~254.9)×10-6,与w(SiO2)呈负相关关系,多数稀土配分曲线相似:轻稀土分异明显大于重稀土。δ(Eu)为0.64~0.19,铕的亏损随w(SiO2)增大而增大。Ni,Cr,Co,Sc,V和Sr随w(SiO2)增大而变小,Rb增大,Th和Th/U比值呈正相关,Ta与Nb/Ta呈负相关。岩体的主量元素、稀土和微量元素的变异主要由深熔过程引起,而不是结晶分异作用引起的。主要源岩是富长英质的,而不是富泥质的,其矿物组合可能是普通角闪石 黑云母 斜长石 钾长石 石英,与北大河岩群很相似。  相似文献   

Effects of dietary carbohydrates sources on lipids compositions in abalone, Haliotis discus hannai Ino     

Weifang Wang  Kangsen Mai  Wenbing Zhang  Wei Xu  Qinghui Ai  Chunfeng Yao  Huitao Li 《中国海洋大学学报(英文版)》2009,8(3):254-258

A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates (dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively), all containing a carbohydrate level of 33.5%, were fed to abalone (initial shell length: 29.98 mm ± 0.09 mm; initial weight: 3.42 g ± 0.02 g) for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly (P < 0.05) higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly (P < 0.05) higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20:4n-6 in the foot muscles were significantly (P < 0.05) lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20:4n-6 in hepatopancreas was significantly (P < 0.05) lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22:6n-3 in the foot muscles were significantly (P < 0.05) lower in the abalone fed with dextrin and heat-treated wheat starch than those fed with wheat starch and potato starch.  相似文献   

山东半岛南部近海大气气溶胶水溶性离子的化学组成   总被引：2，自引：0，他引：2  

杨桂朋  宿鲁平 《中国海洋大学学报(自然科学版)》2009,39(4)

为研究陆源输入对中国近海大气气溶胶的影响,于2007年春季和秋季对山东半岛南部近海进行气溶胶采集工作.分析结果表明气溶胶水溶性离子中主要无机离子无显著的季节性变化,其中二次离子(nss-SO2-4,NO-3,NH+4)浓度最高,占总测定离子浓度的80%以上.甲磺酸离子浓度春季明显高于秋季,分别为(0.041±0.022)和(0.012±0.003 1)μg·m-3,导致生源硫酸盐对非海盐硫酸盐的贡献率分别为4.5%和1.5%;另一方面海盐源硫酸盐分别占总硫酸盐浓度的3.3%和3.9%,以上结果表明人为输入源占山东近海大气气溶胶中硫酸盐来源的主要部分.春季与秋季气溶胶中nss-SO2-4/NO-3值分别为1.43和1.34,反映出近年来中国大气中SO2/NOx呈现出下降趋势.由此可见,来自陆源的人为活动输送导致山东南部近海大气气溶胶的化学组成呈现出明显的陆源特征.  相似文献   

Desilication veins in the Cadillac Mountain granite (Maine, USA): a record of reversals in the SiO₂ solubility of H₂O-rich vapour released during subsolidus cooling     

G. T. NICHOLS  & R. A. WIEBE 《Journal of Metamorphic Geology》1998,16(6):795-808

Late-stage hydrous fluids, which evolved during the cooling of the Cadillac Mountain granite, Maine, USA, produced narrow veins that transect the pluton. The vein margins contain microstructures transitional between granite and the vein centre. They preserve the vestige shapes of original Na-rich alkali feldspar crystals that have been pseudomorphed by cordierite+quartz+K-rich alkali feldspar. Closer to the centres of the veins, the minerals change from an outer zone with cordierite, hercynitic–galaxite spinel, minor corundum, K-feldspar and plagioclase to an inner zone with remnant cordierite, hercynitic gahnite, strongly zoned almandine–spessartine garnet, chlorite and quartz. Three allochemical reactions are inferred to have occurred with the influx of hydrous fluids during the replacement process. Reaction (1) is Na-rich alkali feldspar+iron ions in solution=Fe-cordierite+quartz+K-feldspar+sodium ions in solution. Reactions (2) and (3) occurred during desilication. Reaction (2) is Fe-cordierite=hercynite+silica in solution, and reaction (3) is Fe-cordierite+water=corundum+iron hydroxide in solution+silicic acid in solution. Two independent techniques, experimental silica-solubility data and spinel–cordierite thermobarometry, constrain the conditions of vein formation to c.   1.0  kbar and both methods indicate that the progressive mineral reactions occurred during cooling of the hydrous fluids from c. 775° to 400–340  °C. This cooling trend is consistent with the petrographic evidence, which demonstrates that reactions occurred before desilication, during desilication, and then diminished with a final phase of resilication. Although the veins are minor features of the Cadillac Mountain granite, they provide insight into the conditions that prevailed during cooling of the pluton, and similar features may be important for constraining the cooling history of shallow-level plutonic complexes elsewhere.  相似文献