太阳能固定膜光催化灭菌的特性

以实用型太阳能固定膜光催化中试装置对水中大肠杆菌的灭活特性进行了研究.结果表明,太阳能固定膜光催化灭菌包含光催化灭菌和阳光直接灭菌的协同作用,光催化杀菌效果优于阳光的直接杀菌效果.环境扫描电镜分析(ESEM)表明,光催化处理对菌体产生了致命性破坏.光催化灭菌还具有良好的持久性,灭菌处理8 h后,没有出现明显复活再生现象.光催化灭菌速率随循环流速、光强的增大而增大.太阳能固定膜光催化灭菌技术具有良好的应用前景.     

施硅对白菜体内镉的分布及其吸收迁移的影响

在土壤外源镉污染下,施硅考察土培盆栽条件下白菜体内不同部位间镉的分布及其吸收迁移状况。试验表明,施硅显著降低白菜根、茎、叶中的镉含量和镉累积量,随土壤外源镉污染加剧,施硅抑制白菜各器官吸收累积镉的效果愈好,且不同硅水平处理间的差异亦渐趋显著。硅降低根的镉吸收系数,在土壤外源镉处理下,施硅降低镉的初级转移系数和次级转移系数以及地上部的镉转移系数,显著降低地上部的镉吸收系数;施硅增加白菜根、茎、叶中的硅含量和硅累积量,硅含量和硅累积量的分布为根>叶>茎和叶>茎>根,与镉含量和镉累积量的分布规律一致,白菜体内有可能形成硅-镉复合物以减轻镉的毒害。     

蛋白质组学技术在环境内分泌干扰物分析上应用

为了探讨蛋白质组学技术在环境雌激素分析上的应用,用浓度为3.7×10-9mol/L的17β-雌二醇(E2)处理MCF-7细胞2或3天后进行双向电泳,对比不同的蛋白质提取、染色方法,利用光密度扫描仪将电泳图像数字化,并使用PDQuest软件进行图像分析,以观察雌激素诱导下的蛋白质表达图谱。结果表明,在蛋白质的提取上,冻融法比超声裂解法更有效;在蛋白质染色上,银染法比考马斯亮蓝染色法能得到更多可显示的蛋白质斑点。用E2处理72h后的MCF-7细胞,可检测到40个下调蛋白和5个上调蛋白。该蛋白质表达模式的改变提示了环境雌激素诱导下的特异性蛋白质表达图谱变化。本研究为分析雌激素类内分泌干扰物的内在作用机制提供了一种新的可行方法,也为建立其高通量筛选方法提供了新的思路。     

太阳电池阵等离子体环境下功率泄漏试验研究

目的确定太阳电池空间等离子环境下的功率泄漏特性参数。方法在地面模拟等离子环境下,测量太阳电池阵收集电流随偏置电压的变化规律,再根据计算模型估算太阳电池阵空间环境下的功率泄漏数值。结果太阳电池收集电流随偏置电压的增大而增大,达到一定阈值后,发生收集电流突变现象,实际测试电流值大于100 mA,功率泄漏百分比大于14.3%。辉光放电伴随收集电流突变过程,等离子体鞘层从太阳电池的导体部分扩展到介质部分;收集电流突变发生后,测量电池暗特性,未发现明显损伤。结论针对未来高电压大功率太阳电池阵,应采用功率泄漏试验,检验其功率泄漏特性,建议综合考虑多方面的因素规避发生收集电流突变风险。     

基质浓度·电极距离·离子强度对MFC影响的研究

以宜兰酒厂废水处理厂的污泥为菌种来源,构建单槽无膜无介体空气阴极型微生物燃料电池(Microbial Fuel Cell,MFC),通过添加小同浓度的基质、改变阳极与阴极距离及添加不同浓度的NaCl,分别考察了基质浓度、电极距离、离子强度对MFC性能的影响.研究结果表明,伴随基质COD浓度的增加(从300 mg/L增到...     

Temporal and spatial variations of low-molecular-weight organic acids in Dianchi Lake, China

Low-molecular-weight organic acids (LMWOAs) in eutrophic lake water of Dianchi, Southwestern China Plateau were investigated diurnally and vertically using ion chromatography. Two profiles (P1 and P2) were studied due to the difference of hydrochemical features. Lactic, formic, pyruvic and oxalic acid were detected as major components at P1 and P2 which were on average 7.98 and 6.53 mol/L, respectively, corresponding to their proportions of 2.68% and 2.48% relative to DOC. Pyruvic acid was regarded as the uppermost species at P1 and P2, reaching up to 3.82 and 3.35 mol/L and accounting for 47.9% and 51.3%, respectively, in individual TOA. Although humus were of biogenetic production at both sites, the significant negative correlation between diurnal variations of TOAs, fluorescence intensity (FI) of protein-like components and humic-like components at P1 indicated LMWOAs were greatly originated from bacterioplankton excretion and degradation. However, correlations between diurnal variations of humic-like FI and physicochemical parameters demonstrated algal origination of LMWOAs at P2. Although content of humus was high, TOA at P2 was 1.45 mol/L lower than that at P1, due to the co-influence of more intense photo-oxidation and aggregation at P2. Therefore, TOAs exhibited quite opposite diurnal variation trends of increasing-decreasing and decreasing-increasing at P1 and P2, respectively. Except for impact of solar radiation, bacterial decomposition and assimilation rendered shifts of maximal LMWOAs along water column at P1. Covering with massive algae, UV rays penetrated shallower depth that LMWOAs assembled in surface layer water before 18:00 at P2 and represented decreasing profiles.     

Elevated atmospheric CO2 and drought effects on leaf gas exchange properties of barley

Atmospheric CO₂ concentration (C_a) is rising, predicted to cause global warming, and alter precipitation patterns. During 1994, spring barley (Hordeum vulgare L. cv. Alexis) was grown in a strip-split-plot experimental design to determine the effects that the main plot C_a treatments [A: Ambient at 370 μmol (CO₂) mol⁻¹; E: Enriched with free-air CO₂ enrichment (FACE) at ∼550 μmol (CO₂) mol⁻¹] had on several gas exchange properties of fully expanded sunlit primary leaves. The interacting strip-split-plot irrigation treatments were Dry or Wet [50% (D) or 100% (W) replacement of potential evapotranspiration] at ample nitrogen (261 kg N ha⁻¹) and phosphorous (29 kg P ha⁻¹) fertility. Elevated C_a facilitated drought avoidance by reducing stomatal conductance (g_s) by 34% that conserved water and enabled stomata to remain open for a longer period into a drought. This resulted in a 28% reduction in drought-induced midafternoon depression in net assimilation rate (A). Elevated C_a increased A by 37% under Dry and 23% under Wet. Any reduction in A under Wet conditions occurred because of nonstomatal limitations, whereas under Dry it occurred because of stomatal limitations. Elevated C_a increased the diurnal integral of A (A′) that resulted in an increase in the seasonal-long integral of A′ (A″) for barley leaves by 12% (P = 0.14) under both Dry and Wet - 650, 730, 905 and 1020 ± 65 g (C) m⁻² y⁻¹ for AD, ED, AW and EW treatments, respectively. Elevated C_a increased season-long average dry weight (DW_S; crown, shoots) by 14% (P = 0.02), whereas deficit irrigation reduced DW_S by 7% (P = 0.06), although these values may have been affected by a short but severe pea aphid [Acyrthosiphon pisum (Harris)] infestation. Hence, an elevated-C_a-based improvement in gas exchange properties enhanced growth of a barley crop.     

类芬顿调理污泥用于微生物电解池产氢与磷回收的研究

为提高微生物电解池(MEC)利用剩余污泥产氢气和磷回收的效率,采用Fe~(3+)、原儿茶酸(PCA)和H_2O_2体系预调理污泥,探究中性PCA/Fe~(3+)/H_2O_2体系的试剂投加量对污泥液相总磷含量和溶解性化学需氧量(SCOD)的影响.在单因素试验的基础上,通过表面响应法(RSM)优化得到Fe~(3+)和H_2O_2投加量分别为12.96 mmol·L~(-1)和0.45 mol·L~(-1),液相总磷含量和SCOD含量实际值分别为(60.14±0.08) mg·L~(-1)和(3357.67±66.37) mg·L~(-1),模拟效果显著.与未处理的剩余污泥MEC反应器出水相比,经过调理后的剩余污泥MEC反应器出水中的总化学需氧量(TCOD)、多糖和蛋白质的去除率分别提高了30.03%、50.16%和97.31%,氢气转化率提升了1.31倍,有效提升了MEC产氢效率.通过鸟粪石结晶回收MEC污泥上清液中的磷,发现在初始pH值为10、Mg~(2+)浓度为0.056 mol·L~(-1)和NH~+_4浓度为0.08 mol·L~(-1)时效果最佳.鸟粪石晶体质量浓度最高可达7.6 g·L~(-1),晶体纯度最大为88.30%,上清液中77.55%的磷以鸟粪石的形式得到回收.在本研究最优化条件下进行中性PCA/Fe~(3+)/H_2O_2体系调理剩余污泥微生物电解池产氢与磷回收全过程中产出经济价值达到2.36元.实验研究最终表明,经过Fe~(3+)/PCA/H_2O_2体系调理污泥可促进污泥中磷的释放和MEC处理污泥的产氢效率,为探究污泥资源化提供了新的研究思路.     

中国人为热变化及其对地表能量平衡的影响

利用人口统计、分布数据及能源消费统计资料,对中国1980~2015年人为热通量（Q_a）的时空变化进行了研究,并将其与地表净太阳辐射（R_n）进行了对比分析,以探讨人为热对不同尺度地表能量平衡的影响.结果表明,在研究时段内,全国平均Q_a呈显著升高趋势（0.11W/m²/10a,P<0.001）,从1980年的0.07W/m²上升到2015年的0.45W/m²,已经约相当于全球工业革命以来CO₂排放引起辐射强迫（1.68W/m²）的27%;其中Q_a高值区（≥ 1.00W/m²）已由1990年的点状分布变为2015年的面状分布,占到全国面积的10%;全国平均R_n的趋势率（0.18W/m²/10a）略大于Q_a,但未通过显著性检验（P=0.381）.对于参与计算的31个省会城市,2015年市区Q_a平均值在1~32W/m²之间,平均达17W/m²,相当于R_n平均值（147W/m²）的12%;在栅格尺度上（0.5min×0.5min）,除拉萨外,其余城市的Q_a像元最大值均超过了120W/m²,已经导致局地的热平衡发生了本质变化.研究认为,人为热释放因素不但需要在城市气候模拟研究中给予更多考虑,而且在全球和区域气候模拟与评价中以及制定气候变化应对策略时也有必要给予充分考虑,以促进全面认识并减缓气温升高.     

LMC低压长袋除尘器在矿热炉烟气治理中的应用

阐述了LMC型低压长袋脉冲喷吹除尘器在矿热炉烟气治理中的成功应用。LMC型除尘器在设计上充分考虑到矿热炉高温烟气温度和粉尘性质对设备的影响,并根据不同烟气温度、粉尘性质及工艺的变化,采用不同配件和材料。