不同植被恢复模式下土壤微生物及酶活性的比较——以嘉陵江上游地区为例

研究了嘉陵江上游退耕还林区内5种植被恢复模式下土壤微生物、土壤酶活性以及理化性质。结果表明：①5种植被恢复模式土壤微生物数量、酶活性以及有机质、全氮含量等均明显高于无植被对照；②不同植被恢复模式土壤微生物总数：火烧迹地灌丛﹥刺槐林﹥湿地松×刺槐混交林﹥青冈林﹥湿地松﹥对照地；③不同植被恢复模式下土壤酶活性不同，表层土壤脲酶活性：火烧迹地灌丛﹥青冈林﹥刺槐林﹥湿地松﹥混交林﹥对照地，蔗糖酶（转化酶）：火烧迹地灌丛﹥湿地松﹥青冈林﹥刺槐林﹥混交林﹥对照地，过氧化氢酶活性各林分间变化不明显。     

Optimization of the electrocoagulation process for the removal of copper, lead and cadmium in natural waters and simulated wastewater

Chemical, electrochemical and flow variables were optimized to examine the effectiveness of the electrocoagulation process for the removal of copper, lead and cadmium. The electrochemical process, which uses electrodes of commercial laminate steel, was applied to simulated wastewater containing 12 mg dm(-3) of copper, 4 mg dm(-3) of lead and 4 mg dm(-3) of cadmium. The optimum conditions for the process were identified as pH=7, flow rate=6.3 cm(3) min(-1) and a current density between 31 and 54 A m(-2). When the electrode geometric area and time of electrolysis reached critical values, the copper removal reached a maximum value of 80%. A linear relationship was identified between the current density and the mass of generated sludge. In addition, a linear relationship was found between specific energy consumption and current density. The results of this investigation provide important data for the development of an industrial-scale electrolytic reactor.     

地震活动性的自助统计分析及其在河南省及邻区地震预报中的应用

引用自助统计分析 ,对华北地区 17次中强地震前地震活动震级分布的离散度自助统计方差σBM值与地震活动的关系进行了分析和研究 ,总结出了中强地震前地震活动离散度自助统计方差σBM值的异常特征。同时 ,把该方法应用到了河南及邻区中等地震预报研究中 ,制定了预报规则 ,进行了预测内符检验和预报评分。结果表明 ,该方法是一种有效的中短期地震预报方法 ,具有推广应用价值     

Daily Activity and Mobility of the Common Shrew (Sorex araneus L.)

Data on the daily activity and mobility of the common shrew (Sorex araneusL.) were obtained by the method of animal marking and recapturing in test plots. Sex- and age-related differences in the locomotor activity of animals were revealed, which depended on population size and the phase of the population cycle. Under natural conditions, animal activity in the daytime proved to decrease to a lesser extent than in captivity. The mobility (locomotor activity) of shrews was shown to depend on population density, reproductive rate, and weather.     

BIOLOGICAL MONITORING OF BLUEGILL ACTIVITY1

ABSTRACT: Bluegills were exposed for one hour to 0.2 or 2.3 mg/liter water soluble fraction (WSF) of JP-4 in a testing chamber designed to contain individual fish. A strain gage paddle was used to monitor activity. Whole body movement of individual fish did not change appreciably during exposure to either 0.2 or 2.3 mg/liter WSF-JP-4. Strength of pectoral fin movement, accounting for the majority of the fish behavior, increased in six of ten individuals exposed to 2.3 mg/liter WSF-JP-4. Pectoral fanning may be a useful parameter to indirectly assess water quality.     

苹果茎沟病毒对梨树幼苗生长及过氧化物酶活性的影响

Based on growth level and peroxidase activity, a comparative study and paried-samples t test were made between vires-free Zaosu pear seedlings and the seedlings inoculated with apple stem grooving virus(ASGV). The results showed : ( 1 )virus-free Zaosu pear seedlings grew better than inoculated ones. Of the seedlings the height, diameter, branches and autumn braches differed statistically significantly; (2)the peroxidase activity of inoculated seedlings was higher than that of virus-free ones, and the peak of peroxidase activity occurred on about d 7 and d 24 after inoculation. Fig 1, Tab 1, Ref 9     

Contaminant Exposure of Barn Swallows Nesting on Bayou D'Inde, Calcasieu Estuary, Louisiana, USA

Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d′Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d′Inde (2.8 μ g/g PCBs in eggs and 1.5 μ g/g PCBs in nestlings) than at the other two sites (< 0.2 μ g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d′Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.     

石墨炉AAS法分析冬青科苦丁茶树系统中镉及其分布

采集海南大学苦丁茶种质资源库中6种冬青科(Ilex)苦丁茶树的根、茎、叶及对应土壤样品,通过试验研究,建立了高压密封消解-石墨炉原子吸收光谱法测定样品中镉的方法。对植物样和土壤样分别采用硝酸-双氧水和硝酸-高氯酸-氢氟酸混酸体系进行消解。以磷酸二氢铵作为基体改进剂,并开启氘灯校正背景,在优化的工作条件下测定样品中镉。该方法的检出限为0.300ng/mL,用于实验样品中镉的测定,其相对标准偏差RSD5%,加标回收率介于94%～108%之间。用该方法对茶叶(GBW10016)和土壤(GBW-07407)标准参考物中镉进行了测定,测定结果与标准值相符合,相对误差小于7%。冬青科苦丁茶树及其土壤中镉的分布具有特征性,主要表现为:土壤茶树,根际土壤非根际土壤,吸收根主根或茎,嫩叶老叶枯叶。     

黄石沿江土壤镉的形态特征及生物可利用性

为了解黄石市沿长江冲积土壤中重金属镉直接和潜在的危害程度,为重金属污染防治提供科学依据,采用总量测定、Tessier连续提取法,分析研究了湖北黄石市沿江冲积土壤中重金属镉的总量及不同形态含量,镉含量采用火焰原子吸收分光光度法测定。结果表明,研究区土壤Cd全量都大于2mg/kg,不同形态Cd含量相对大小依次为残渣态铁锰氧化物结合态碳酸盐结合态有机物结合态离子交换态。其中残渣态占全量比例为58%,铁锰氧化物结合态为26%,碳酸盐结合态、有机物结合态、离子交换态分别为8%、4%和3%。可见研究区Cd的生物可利用态含量低,生物潜在可利用态较高,生物不可利用态含量最高;现有环境条件下的土壤Cd比较稳定,生物可利用性较低,对农作物的危害性较小。     

废水处理系统中酯酶的活性及其作用特性

文章对兼氧-好氧染料废水生物处理系统中微生物酯酶的活性及其作用特性作了较深入的研究。试验结果表明,酯酶在兼氧和好氧池中的平均活性分别达0.482μmo·lh·g-1和0.408μmo·lh·g-1。酯酶活性同废水的COD和色度去除率之间存在很好的相关性。在pH值为8,温度为60℃条件下,兼氧和好氧池中的酯酶活性最高。较低的染料浓度有利于提高系统中酯酶的活性,超过一定浓度酯酶活性降低。染料助剂EDTA和氯化锌对兼氧池中酯酶活性的抑制作用明显,而好氧池中酯酶活性几乎不受这些助剂的影响。