改性花生壳吸附废水中Cr（Ⅵ）条件的优选试验

[目的]研究改性花生壳对废水中Cr（Ⅵ）的吸附性能。[方法]用磷酸溶液对花生壳进行改性处理,制备不同浓度的Cr（Ⅵ）溶液,采用单因素试验研究Cr（Ⅵ）初始浓度、改性花生壳投加量、pH值、反应时间对吸附率的影响,并通过正交试验优化改性花生壳对废水中Cr（Ⅵ）的吸附条件。[结果]极差分析可知,在影响吸附效果的因素中,pH值的影响最大,投加量和反应时间次之,Cr（Ⅵ）初始浓度的影响最小。最佳吸附条件为：pH值为2.0,Cr（Ⅵ）浓度为40mg/L,花生壳粉末投加量为30g/L,反应时间为100min,对Cr（Ⅵ）的吸附率可达96.81%。改性花生壳对含Cr（Ⅵ）废水的吸附性能明显高于未改性花生壳。[结论]该研究为花生壳的综合利用和含Cr（Ⅵ）废水的处理研究提供有价值的参考。     

改性高岭土对水中磷的吸附行为研究

[目的]探讨改性高岭土吸附磷的规律和最佳吸附条件。[方法]先取一定量的高岭土加入含Al3＋和Mg2＋的溶液,制备成改性高岭土,然后在6mg/LKH2PO4的水溶液中,加入改性高岭土,恒温振荡一定时间,静止过滤,分析滤液中磷的含量,计算磷去除率,研究pH值和改性高岭土用量对磷吸附处理效果的影响以及吸附时间对磷去除时间的影响。[结果]改性高岭土对磷具有较好的吸附去除效果,其最佳吸附条件为：pH值为5～7,反应时间控制在30min,吸附剂的合适投加量为4g/L,在此条件下,磷的去除率超过80%。改性高岭土对磷的吸附符合Langmuir吸附等温线,以化学吸附为主。[结论]改性高岭土吸附磷效果好,运行操作稳定,吸附磷后的高岭土还可作为农田肥料,实现了废水治理和污染物磷资源化的双重目的。     

凉粉草基因组DNA提取与分析

[目的]为分子生物学研究提供高质量、高产量的凉粉草总DNA。[方法]采用改良CTAB法提取总DNA,通过测定OD260/OD280值、琼脂糖凝胶电泳和RAPD扩增对所得DNA的浓度和质量进行检测,考察该方法对DNA的提取效果。[结果]改良CTAB法提取的总DNAOD260/OD280值为1.6～2.0;电泳条带清晰,完整性好,纯度高,总DNA分子量与λDNA相近;以所提DNA为模板进行RAPD扩增时,可得到稳定的扩增条带。[结论]改良CTAB法适合凉粉草基因组DNA的提取。     

改性高铝水泥吸附除去水中氟的研究

采用静态吸附法研究了改性高铝水泥对含氟水的除氟性能,结果表明:用硫酸铝溶液0.5 mol/L浸泡高铝水泥8h制成改性高铝水泥,然后用其与含氟水震荡反应7 h,控制含氟水的pH在6~8范围内,能提高改性高铝水泥的吸附率,对含氟10 mg/g的溶液,此优化条件下的最大除氟率约96%。     

亟待开展转基因作物商业化整体战略研究

2008年的粮食危机使转基因作物商业化重新成为争论的焦点,我国在2008年启动了转基因生物新品种培育科技重大专项,标志着我国转基因作物商业化又迈进了一步。然而,目前缺乏对转基因作物商业化整体战略的研究。转基因作物商业化是一个复杂的综合性问题,涉及粮食安全、知识产权、经济社会环境影响、种业及农业生物技术产业发展等问题。文章分析了转基因商业化整体战略研究的背景和必要性,提出了整体战略研究的目标,最后提出了整体战略研究的框架。     

冰温结合不同比例二氧化碳气调对冷却肉保鲜的影响

研究了在冰温基础上结合不同二氧化碳比例气调对冷却肉保鲜的影响,结果表明,冰温条件下,二氧化碳浓度越高抑菌效果越明显,气调包装实验组的挥发性盐基氮始终维持在较低水平,80%CO2的a*值最低,20%CO2的汁液流失率在24 d时最高,汁液流失率较少的实验组普遍保水能力较弱。     

西部地区农村居民食品消费的实证研究——基于修正的AIDS模型

利用1992～2005年西部11个省市区农村居民12类食品消费数据,基于修正的AIDS模型,实证分析了西部农村居民食品消费结构以及其消费行为对食品需求的影响。     

Determination of carbendazim with multiwalled carbon nanotubes-polymeric methyl red film modified electrode

Multiwalled carbon nanotubes-polymeric methyl red film modified electrode (MWNT-PMRE) was made. The electrochemical behavior of carbendazim on modified electrode was studied with Cyclic Voltammetry, Linear Sweep Voltammetry, Stable Polarization Method and Chronocoulometry. The results indicated that the electrical oxidation of carbendazim on MWNT-PMRE in H₂SO₄ supporting electrolyte with concentration of 0.6 mol/L was irreversible and was mainly controlled by diffusion. Some parameters of the electrochemical process were evaluated. The impacts of experiment conditions on the electrochemical behavior of carbendazim were studied. A good linearity relationship between peak current and concentration of carbendazim in the range of 2.0 × 10⁻⁷-1.0 × 10⁻⁵ mol/L was found, of which the equation was I_p(A) = −1.149 × 10⁻⁵ − 2.301c (mol/L), the correlative coefficient R = −0.9953 and detection limit was 9.0 × 10⁻⁹ mol/L. The recovery was between 90.3% and 94.7%.     

Prediction of yield and the contribution of legumes in legume-grass mixtures using field spectrometry

Productivity and botanical composition of legume-grass swards in rotation systems are important factors for successful arable farming in both organic and conventional farming systems. As these attributes vary considerably within a field, a non-destructive method of detection while doing other tasks would facilitate more targeted management of crops and nutrients in the soil–plant–animal system. Two pot experiments were conducted to examine the potential of field spectroscopy to assess total biomass and the proportions of legume, using binary mixtures and pure swards of grass and legumes. The spectral reflectance of swards was measured under artificial light conditions at a sward age ranging from 21 to 70 days. Total biomass was determined by modified partial least squares (MPLS) regression, stepwise multiple linear regression (SMLR) and the vegetation indices (VIs) simple ratio (SR), normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and red edge position (REP). Modified partial least squares and SMLR gave the largest R ² values ranging from 0.85 to 0.99. Total biomass prediction by VIs resulted in R ² values of 0.87–0.90 for swards with large leaf to stem ratios; the greatest accuracy was for EVI. For more mature and open swards VI-based detection of biomass was not possible. The contribution of legumes to the sward could be determined at a constant biomass level by the VIs, but this was not possible when the level of biomass varied.     

改性膨润土吸附处理重金属离子的研究进展

改性膨润土吸附重金属离子具有优良的性能,作为环境吸附材料具有广阔的应用前景。总结了近年来膨润土对重金属吸附处理的应用研究情况,指出了改性膨润土用于处理重金属废水的不足和今后的研究重点,包括再生回收利用、被吸附物质的回收利用。