基于功能安全标准的安全仪表系统可靠性评估软件

介绍了以功能安全国际标准IEC61508和IEC61511工程应用要求为依据,集安全仪表系统的安全仪表功能安全完整性等级(SIL)分配、安全要求规范(SRS)制定、SIL验证、可靠性数据管理等多功能为一体的安全仪表系统可靠性专用评估软件。     

传感技术用于甲醛测定的研究

甲醛是一种重要的工业原料,在化工、食品、建材等方面有着广泛的应用。由于甲醛毒性大,且被怀疑具有致癌作用,目前已被认为是工厂区和室内空气中最重要的污染物之一。随着人们对空气污染的日益关注,对甲醛的准确及时检测显得更加重要。基于传感器技术而研制出的甲醛测定仪,让我们看到传感技术运用于甲醛测定领域的发展前景。本文就测定甲醛的传感器技术如电化学传感器、光化学传感器、金属氧化物传感器、电子鼻以及声表面波式传感器的一些重要应用进行了阐述。     

芳香烃清洁硝化催化剂

综述了国内外有关芳香烃硝化过程中替代硫酸的催化剂的研究进展;介绍了沸石类催化剂、粘土类催化剂、离子交换树脂催化剂、固载化液体酸催化剂、金属氧化物及金属盐催化剂、杂多酸催化剂以及固体超强酸催化剂的合成及催化效率与优缺点.     

磁性石墨烯材料的制备及去除水中重金属的研究进展

石墨烯基材料具有很高的理论比表面积和大吸附容量.将石墨烯与磁性材料复合而成的磁性石墨烯基纳米材料具有强化学稳定性和协同吸附能力,可增强水中重金属离子的去除效率,并能在外加磁场作用下迅速分离.综述了磁性石墨烯材料的制备方法及其在水处理领域的应用进展,指出了当前研究的主要发展方向.     

低pH值对大型溞（Daphnia magna Straus）存活、生长和生殖的影响

在静置换水条件下,研究了低pH值对大型存活、生长和生殖的影响。结果表明,在25±1℃下,急性试验低pH值对大型的24h和48hLL50值及其95％可信限分别为pH值4.66±0.19和4.94±0.20。慢性试验进行了14天,对存活和生长,pH值1.75有影响,pH值5.0没有影响;对生殖,pH值5.0有影响,pH值5.5没有影响。显示出低pH值对大型的毒性阈限在pH值5.00－5.50之间。     

东北玉米热量指数预测方法研究(Ⅲ)——GM(1,1)预测方法

GM(1,1)是开展时间序列环境要素变化趋势预测的有效方法之一。通过对东北地区玉米热量指数的分析,建立了热量指数时间变化趋势的GM(1,1)预测模型,各模型的平均预测精度虽低于逐步回归统计模型,但也都达91%以上,可以应用该模型的预测结果指导农业生产。     

釜溪河自贡城区段季节性低氧成因研究

釜溪河为沱江一级支流,在自贡城区段设有国考碳研所断面。收集碳研所断面近10年来水质自动站数据,分析溶解氧(DO)变化特征,采样调查釜溪河自贡城区段水质及河道底泥污染状况,采用相关性分析、数值模拟等,研究分析釜溪河自贡城区段溶解氧分布特征及碳研所断面季节性低氧成因。研究结果表明,碳研所断面的溶解氧质量浓度变化特征呈现春末夏初最低,白天高晚上低的特征。釜溪河碳研所断面河水耗氧类污染物质量浓度较沱江流域内其他断面高,耗氧强度较大,溶解氧质量浓度较沱江流域其他断面偏低;其次,研究河段中釜溪河污水厂以下河段受污水厂低氧水排入和金子凼堰底层低氧水下泄影响,其溶解氧水平整体较污水厂以上河段低;最后,河段底泥有机质含量较高,春夏季气温升高将导致微生物分解活性增强大量消耗溶解氧,同时,闸坝和外来水体排入的水文扰动造成污水厂以下河段水温梯度弱,表层溶解氧易受底层低氧水影响,促使断面形成季节性低氧现象。溶解氧预测模型结果也进一步证实了温度变化和垂向温度梯度弱是碳研所断面溶解氧质量浓度季节性偏低的主要因素。     

Comparison of the removal of monovalent and divalent cations in the microbial desalination cell

Microbial desalination cell (MDC) is a promising technology to desalinate water and generate electrical power simultaneously. The objectives of this study were to investigate the desalination performance of monovalent and divalent cations in the MDC, and discuss the effect of ion characteristics, ion concentrations, and electrical characteristics. Mixed salt solutions of NaCl, MgCl₂, KCl, and CaCl₂ with the same concentration were used in the desalination chamber to study removal of cations. Results showed that in the mixed salt solutions, the electrodialysis desalination rates of cations were: Ca²⁺ >Mg²⁺>Na⁺>K⁺. Higher ionic charges and smaller hydrated ionic radii resulted in higher desalination rates of the cations, in which the ionic charge was more important than the hydrated ionic radius. Mixed solutions of NaCl and MgCl₂ with different concentrations were used in the desalination chamber to study the effect of ion concentrations. Results showed that when ion concentrations of Na⁺ were one-fifth to five times of Mg²⁺, ion concentration influenced the dialysis more profoundly than electrodialysis. With the current densities below a certain value, charge transfer efficiencies became very low and the dialysis was the main process responsible for the desalination. And the phosphate transfer from the anode chamber and potassium transfer from the cathode chamber could balance 1%–3% of the charge transfer in the MDC.     

加速溶剂萃取(ASE)-固相萃取(SPE)-高效液相色谱法(HPLC)测定土壤中青霉素钠

建立了一种加速溶剂萃取(ASE)-固相萃取(SPE)-高效液相色谱(HPLC)测定土壤中青霉素钠的简单、快速的方法.样品以超纯水为提取溶剂,50℃提取温度为ASE提取条件参数;HLB型固相萃取柱富集净化:6.0mL 5%甲醇淋洗、4.0mL乙腈-甲醇(1∶1)洗脱;高效液相色谱-紫外检测器(HPLC-PDA)测定,检测波长λ=191.1nm,柱温30℃,流动相为乙腈-0.1%甲酸/水(1∶1),采用等梯度洗脱程序,取得较好的检测分离效果.对0.5、2.0、8.0mg·kg-1等3个不同添加浓度水平的青霉素钠平均加标回收率范围为73.1%—89.7%,回收率相对标准偏差RSD范围为1.1%—2.9%(n=5),检出限可达235.0μg·L-1.结果表明,该方法操作简单,快速,准确度和精密度均符合质量控制要求,能够满足环境土壤样本中痕量青霉素钠检测分析的要求.     

New advances in plant growth-promoting rhizobacteria for bioremediation

Plant growth-promoting rhizobacteria (PGPR) are bacteria capable of promoting plant growth by colonizing the plant root. For a long period PGPR were mainly used for assisting plants to uptake nutrients from the environment or preventing plant diseases. Phytoremediation is a new and promising approach to remove contaminants in the environment. But using plants alone for remediation confronts many limitations. Recently, the application of PGPR has been extended to remediate contaminated soils in association with plants. Of all the present contaminants, the profound impacts of organic and heavy metal pollutants have attracted world wide attention. Here we review the progress of PGPR for remediation of soils contaminated with these two sources.