Spatial variations in daily average CO2 concentrations above wetland surface of Xianghai National Nature Reserve, China

Horizontal and vertical variations of daily average CO2 concentration above the wetland surface were studied in Xianghai National Nature Reserve of China in August, 2000. The primary purpose was to study spatial distribution characteristics of CO2 concentration on the four levels of height(0.1 m, 0.6 m, 1.2 m and 2 m) and compare the differences of CO2 concentration under different land covers. Results showed that daily average CO2 concentration above wetland surface in Xianghai National Natural Reserve was lower than that above other wetlands in northeast China as well as the worldwide average, suggesting that Xianghai wetland absorbed CO2 in August and acted as“sink” of CO2. The horizontal variations on the four levels of height along the latitude were distinct, and had the changing tendency of“decreasing after increasing” with the increase of height. The areas with obvious variations were consistent on different levels of height,and those with the highest variations appeared above surface of shore, sloping field, Typha wetland and Phragmites wetland; the vertical variations were greatly different, with the higher variations in Phragmites wetland and Typha wetland, and the lands near the shore and the sloping field with the lower variations. Spatial variations of daily average CO2 concentrations above wet!and surface were affected by surface qualities and land covers.     

热带假丝酵母8953菌株对苯酚的降解特性研究

实验室分离的一株热带假丝酵母(编号为8953)具有较强的苯酚降解能力,并可以利用苯酚、间苯二酚、联苯胺等芳烃为唯一碳源和能源生长。该菌株在48h内可完全降解约14.88mmol/L苯酚,完全降解10.63mmol/L苯酚只需要24h,其降解苯酚浓度最高可达19.13mmol/L。在pH4～9,温度20℃～40℃范围内,苯酚浓度为10.0mmol/L条件下该菌株均保持100%的降解率。该菌株降解苯酚的最适pH范围为6.0～8.0,最适温度范围为28℃～30℃,最佳接种量为1%～3%,外源添加氮源能促进酵母生长和苯酚的降解。     

薄板拉延成形的固定压边间隙控制方式研究

分析了薄板拉延过程中应用固定压边间隙控制方式的成形特点，指出选择合理的压边间隙量是保证冲压件成形质量的关键。应用有限元数值仿真技术，以NUMISHEET＇99圆柱杯深拉延——反向深拉延标准考题(Benchmark-C)为例，模拟了其成形过程，在仿真结果与KimHyungjong的实验结果较好地吻合的基础上，通过对大量仿真计算结果的分析．提出了薄板多工序拉延成形中采用压边间隙控制方式时合理选择间隙量的方法。     

单甲脒农药的微生物降解代谢研究

研究了门多萨假单胞菌ＤＲ－８菌株对单甲脒农药的降解代谢。该菌利用率甲脒作为生长的唯一氮源，其对单甲脒的呼吸作用试验确证了该农药的生物可降解性。单甲脒对细菌生物氧化代谢关联酶活性的影响研究表明，脱氢酶对单甲脒较敏感，而ＮＡＤＨ氧化酶则耐受性较强。     

亚铵制浆黑液非无菌操作连续发酵生产酵母

从土壤中筛选出能在亚铵黑液中生长的毕赤酵母菌株（Ｐｉｃｈｉａ ｓｐ．Ｎｏ．１）经耐毒驯化后，可接种于酸析脱木素和汽提脱毒后的亚铵黑液中，在非无菌操作条件下连续发酵生产酵母菌体，该菌生产迅速，连续培养衡释率达０．２６ｈ＾－１，总糖的酵母得率为０．４８ｇ／ｇ（ＴＳ），ＣＯＤ去除２３％，菌体易絮凝，可自然沉降分离。     

用水基表面活性剂乳液回收废白土中蜡的界面张力研究

通过测定液体与废白土粉末之间的接触角及液体与蜡之间的液液界面张力，对水基表面活性剂乳液的溶剂及配方进行了优选，得到最佳的水基面活性剂乳液的组成为：质量分数０．２％的十二烷基苯磺酸钠＋体积分数为２．５％的乙醇＋体积分数为２５％的混合烃（正己烷＋苯，等体积）＋体积分数为７２．５％的水。实验证明，用该水基表面活性剂乳液处理废白土，蜡的回收率可达８０％，同时不破坏白土的颗粒结构。     

Sensitivity experiments and assessment of climatic changes in China induced by greenhouse effect

Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in China .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in China as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in China due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in China, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.     

南海ODP1144孔微玻璃陨石物理化学性质及母源物质的复杂性

ODP 184航次 114 4孔位于南海北部陆缘 (2 0°3.18′N ,117°2 5 .14′E ,水深 2 0 37m) ,在岩心样品中发现的微玻璃陨石主要赋存于 386 .17～ 386 .2 7mcd处 ,这些玻璃陨石主要以球形和椭球形为主 ,可见泪滴状、马鞍形、扁豆形、圆盘形、哑铃形、翼形、异形等形态和不规则状碎片。通过微玻璃陨石主量元素电子探针分析 ,并用Harker图解讨论了主量元素氧化物之间的相关性 ,同时结合Niggli参数进一步深入探讨微玻璃陨石的母源物质特征。研究结果表明 ,ODP114 4孔微玻璃陨石属于澳亚散落区内的普通型微玻璃陨石 ,其母源物质成分复杂 ,可能有两种或两种以上的物质组成 ,一种可能是化学成分没有太大变化的碎屑沉积岩 ,另一种可能是粘土及杂砂岩等。     

水质模拟及趋势分析

根据洛河、伊河河流及流经地区特征 ,选择具有代表性的断面 ,选用一维河流有限差分水质模型 ,计算洛河、伊河 1 995～2 0 0 0年主要断面污染物浓度 ,并对其进行评价。采用季节性肯达尔检验法 ,对计算出的洛河、伊河 1 995～ 2 0 0 0年主要断面污染物浓度进行趋势分析 ,并分析其变化特征及形成原因     

Effects of environmental factors on the production and release of matrix-bound phosphine from lake sediments

Effects of pH, temperature, and oxygen on the production and release of phosphine in eutrophic lake sediments were investigated under laboratory tests. Results indicated that the elimination of matrix-bound phosphine was accelerated under initial pH 1 or 12. Phosphine levels could reach maximum under initial pH 10. The contents of phosphine increased with the addition of alkali under pH 4–12. The rates of phosphine production and release from lake sediments varied with temperature. 20°C was the most favorable temperature for the production of matrix-bound phosphine. Oxygen showed little effect on matrix-bound phosphine. Matrix-bound phosphine concentrations in lake sediments were concluded to be dependent on a balance of natural generation and depletion processes. Translated from Acta Scientise Circumstantiae, 2005, 25(5): 681–685 [译自: 环境科学学报]