稀有鮈鲫成体神经发生相关基因的分子克隆及序列分析

成体神经发生是脊椎动物中广泛存在的一种生物学特征。成体硬骨鱼类的脑展现出强烈的神经活性以及出色的脑修复能力,这使得硬骨鱼类成为研究成体神经发生和脑修复的一个理想的模型。本文克隆了成体稀有鮈鲫(Gobiocypris rarus)脑组织中神经发生及脑修复相关的hes5、pax6、sox11和prox1基因的部分c DNA序列并进行了序列分析。序列分析结果表明,pax6和sox11基因片段与斑马鱼(Danio rerio)对应的基因片段的同源性最高,分别为97%和94%;hes5基因与鲤鱼(Cyprinus carpio)相对应的基因片段的同源性最高,为92%;prox1基因在物种间的同源性最低。基于稀有鮈鲫和已知物种相应基因的核苷酸序列构建了系统发育树,发现稀有鮈鲫prox1基因与其他硬骨鱼类的亲缘关系最远。本文为进一步开展神经毒性类化学品对水生生物鱼类的成体神经毒性作用机制研究提供了分子生物学基础。     

Fate of antimicrobial resistance genes in response to application of poultry and swine manure in simulated manure-soil microcosms and manure-pond microcosms

This study aimed to determine the occurrence, abundance, and fate of nine important antimicrobial resistance genes (ARGs) (sul1, sul2, tetB, tetM, ermB, ermF, fexA, cfr, and Intl1) in the simulated soil and pond microcosms following poultry and swine manure application. Absolute quantitative PCR method was used to determine the gene copies. The results were modeled as a logarithmic regression (N?=?mlnt?+?b) to explore the fate of target genes. Genes sul1, Intl1, sul2, and tetM had the highest abundance following the application of the two manure types. The logarithmic regression model fitted the results well (R ² values up to 0.99). The reduction rate of all genes (except for the genes fexA and cfr) in manure-pond microcosms was faster than those in manure-soil microcosms. Importantly, sul1, intl1, sul2, and tetM had the lowest reduction rates in all the samples and the low reduction rates of tetM was the first time to be reported. These results indicated that ARG management should focus on using technologies for the ARG elimination before the manure applications rather than waiting for subsequent attenuation in soil or water, particularly the ARGs (such as sul1, intl1, sul2, and tetM investigated in this study) that had high abundance and low reduction rate in the soil and water after application of manure.     

DO浓度对间歇曝气单级自养脱氮系统N2O排放的影响

以单级自养脱氮系统为研究对象,采用有效容积为15 L的SBBR反应器,系统进水NH+4-N浓度约为360 mg/L,控制温度为(30±2)℃,采用间歇曝气方式运行,曝气段DO浓度从2.4~2.6 mg/L逐渐下降到0.9~1.1 mg/L,研究了单级自养脱氮系统的脱氮性能与N2O排放情况。结果表明,反应器曝气段DO浓度从2.4~2.6 mg/L下降到0.9~1.1mg/L,系统TN去除率均达到80%,但在相同运行时间内的TN去除率依次降低,NH+4-N平均反应速率从0.19 mg/(L·min)降低至0.05 mg/(L·min),NO-3-N累计产生量稳定于14.9~16.5 mg/L,NO-2-N浓度在反应器内未产生明显的积累。随着曝气段DO浓度的下降,最大N2O释放速率逐渐降低,N2O累计释放量从73.8 mg下降到61.0 mg,N2O转化率介于2.4%~2.9%。     

基于MODIS数据的安徽区域日蒸散量估算与分析

蒸散的估算在区域能量平衡和水资源研究中具有重要意义,遥感技术发展促进了区域蒸散的研究。利用安徽省气象资料、MODIS数据产品及GIS背景信息,基于SEBAL模型,按1 km空间分辨率进行了面尺度的安徽省日蒸散量估算,并在GIS空间分析模块的支持下对不同土地覆盖类型的日蒸散量进行统计分析。结果表明：遥感估算的蒸散量与利用Penman Monteith公式计算的蒸散量比较,两者之间具有较好的相关性,遥感蒸散估算值整体偏小,不同土地利用类型的日蒸散量间差异显著。遥感蒸散估算方法在安徽省具有一定的实用性,需优化模型参数,以提高其进一步技术推广的前景     

Iron improving bio-char derived from microalgae on removal of tetracycline from aqueous system

Novel magnetic carbonaceous bio-char was hydrothermal prepared from microalgae under different loadings of iron and its structures and surface chemistry were characterized with Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm (BET). The morphology of bio-char changed from sheet to particle as iron loading increased and its surface area also increased. When 3.0 g of dried microalgae and 6.0 mmol iron salt ((NH₄)₂SO₄·FeSO₄·6H₂O) were mixed and treated, the obtained bio-char possessing the highest amount of oxygen-containing functional groups resulted in the best adsorption performance on tetracycline (TC). This adsorption process was fitted to Langmuir adsorption isotherm and the maximum adsorption capacity was 95.86 mg/g, which is higher than other bio-char reported. The iron loading contributed to the higher adsorption capacity of bio-char, which may be due to three factors, the high surface area, more hydrogen bonding, and bridging effects of the structural Fe for TC. Our data suggest that bio-char may have more important role in stabilization of pollutants in the environment.     

磷石膏水热法合成硫酸钙晶须

以磷石膏为原料,二水合硫酸钙、硫酸镁、甘油为添加剂,采用水热法合成硫酸钙晶须,考察了料浆含量、反应温度、反应时间、体系pH等因素对晶须的直径和长径比的影响;并采用SEM技术观察硫酸钙晶须的形貌。实验结果表明,当磷石膏含量2.5%（w）、反应温度130 ℃、反应时间4 h、体系pH 4时,制备得到的硫酸钙晶须长径比为56.24,平均直径为0.17 μm。SEM表征结果显示,硫酸钙晶须形貌规整、分散均匀、直径较小,达百纳米级。     

炼油废水污泥脱水工艺条件的优化

采用化学除油降黏—污泥调理—离心脱水工艺处理某炼油厂废水处理系统的混合污泥,并对工艺条件进行优化。实验结果表明,最佳的工艺条件为：化学除油降黏阶段处理体系的pH=4,反应温度35 ℃,H₂O₂加入量 2 g/L,m（H₂O₂）∶ m（Fe²⁺）=4,反应时间 60 min;污泥调理反应阶段的CaO加入量7.0 g/L;离心脱水阶段在分离因数为1 558时脱水5 min。在此条件下,得到的泥饼的含水率为70.0%~75.0%（w）,含油率小于2%（w）,污泥比阻约为3.0×10⁷ s²/g。     

罐底含油泥热解动力学参数计算方法的优选

在化学反应设计中反应动力学是较重要的因素。为得到更合理的污泥热解动力学参数计算方法,利用热重分析仪,在氮气气氛下对罐底含油污泥的热解特性进行研究。根据热重实验数据,分别采用Coats-Redfern法、Kissinger法、FWO法和Popescu法计算污泥热解动力学参数,并获取罐底泥热解制油的主要阶段(第2阶段)的反应活化能E、频率因子A并分析各种方法反应机理。通过对比不同计算方法得到动力学参数及拟合曲线与实验曲线的相关性,确定了最佳罐底含油污泥热解动力学参数计算方法。研究表明,Popescu法得到罐底泥的热解过程符合Jander方程,活化能E为101.43 kJ/mol,与FWO法得到的91.20 kJ/mol相近,且预测曲线与实验曲线有较好的相关性(0.9816),说明Popescu法计算罐底泥热解动力学参数更合适。     

酸性矿井水中和沉淀法除铁优化

针对山西某煤矿高矿化度、高铁酸性矿井水除铁效果差、出水容易返色等问题,采用NaOH中和调pH、曝气及化学氧化等处理工艺进行酸性矿井水中和沉淀法除铁优化实验研究。结果表明,采用NaOH中和沉淀法除铁时,投加中和剂使出水pH达6.7以上时,出水中铁含量低于10 mg/L,满足排放要求。对于本实验废水NaOH所需投加量为2.8 g/L,铁的去除率可达到99.75%;以H2O2对原水进行氧化处理,可迅速将Fe(Ⅱ)氧化成Fe(Ⅲ),其用量与原水中Fe(Ⅱ)的含量成正比。当其用量为1.6 mL/L时,可将原水中的Fe(Ⅱ)完全转化为Fe(Ⅲ),投加中和剂使出水pH达到4.5以上时,能使出水中铁含量满足排放要求。对于实验废水所需的NaOH投加量为2.0 g/L,比直接中和沉淀所需的NaOH用量要节省28.6%。曝气处理对原水中Fe(Ⅱ)的氧化效果不明显。     

香根草人工湿地处理生活污水的试验研究

通过建立香根草人工湿地系统,研究该系统对生活污水的COD、TP、TN的处理效果以及系统的耐污性。在水力停留时间(HRT)为6h的条件下,COD、TP、TN的去除率分别为63.5%、88.3%、72.4%。研究表明,香根草人工湿地系统对城镇生活污水具有较好的净化效果,且系统在该试验条件下耐污性良好。