影响Fenton法处理晚期垃圾渗滤液COD_(cr)去除因素的研究

采用Fenton试剂氧化法处理晚期垃圾渗滤液,对初始pH、H2O2/Fe2+比、H2O2投加量及反应时间等影响化学需氧量(COD)去除率的各因素进行了研究。得出Fenton试剂氧化法处理晚期垃圾渗滤液的最佳条件为:初始pH为4,H2O2/Fe2+比为5:1,H2O2投加量为0.05mol·L-1,反应时间为2.5h。此时COD去除率可达73.1%。     

光照条件对丽格海棠不定芽诱导和增殖的影响

［目的］研究光照条件对丽格海棠体外快繁的影响。[方法］用丽格海棠幼嫩叶片作为外植体,给予不同光照条件,观察不定芽的诱导率和增殖率。［结果］在1 000 lx光照条件下培养14 d,后移到2 000 lx光照条件下培养的不定芽诱导率最高,可达100%;在2 000 lx的光照条件时,增殖效果最好。［结论］不同光照强度直接影响丽格海棠不定芽的诱导和增殖。     

Wind Damage Estimation and Prediction of Light Steel Industrial Buildings

Wind hazard damage estimation was addressed for light steel industrial buildings which were the typical wind vulnerable structures in southeast coastal cities. With parametric analysis of wind damage and the structural failure features, the envelop elements and the connecting elements were determined as the pivots of the damage analysis. Upon the consideration of the co effect of exterior wind pressure, wind induced internal pressure and windborne debris damage, a typhoon load model was proposed. And with the calculation method of the element resistance from the regulation, the procedure of the damage estimation was described and the damage classification of industrial buildings was specified with detailed indicators. Finally, the proposed method was approved with the actual data of typhoon CHANCHU (0601).     

面向国家级生态区建设的水资源可持续利用对策研究——以深圳市龙岗区为例

随着经济社会的快速发展,深圳龙岗区水资源紧缺矛盾日益突出。从龙岗区的水资源现状和水资源开发利用情况出发,按照国家级生态区建设和可持续发展要求,预测了未来龙岗区水资源需求,分析了龙岗水资源开发利用当前面临的问题,最后从产业调整、水源配置、水环境控制、水资源管理等方面提出龙岗区水资源的可持续利用对策。     

薯蓣皂苷元微胶囊的制备及体外抗肿瘤活性

[目的]制备薯蓣皂苷元微胶囊并对其性能进行表征,探讨微胶囊的体外抗肿瘤活性。[方法]通过喷雾干燥技术制备薯蓣皂苷元微胶囊,采用MTT法对它们的体外抗肿瘤活性进行评价。[结果]以明胶为壁材制备了薯蓣皂苷元微胶囊,并对微胶囊的粒径分布、超微结构和包封率进行了表征。以明胶薯蓣皂苷元配比为5：1制备的微胶囊,包埋率为78%～94%,平均粒径约13μm。细胞试验表明,当药物浓度为40mg/L时,生物体外培养的人结肠癌细胞（C26）有72%被抑制,具有良好的抑癌效果。薯蓣皂苷元微胶囊对C26细胞体外抗增值活性与薯蓣皂苷元相比有了明显提高。[结论]薯蓣皂苷元微胶囊的抗肿瘤活性较薯蓣皂苷元明显提高。     

暖季型草坪草冬季保绿研究进展

通过分析冬季草坪草枯黄的原因,从草坪管理、植物生长调节剂应用、施肥尤其施用新型草坪肥料等方面,比较不同保绿方法对冬季草坪草生理生态和延长绿期的影响,为草坪冬季管理和提高草坪冬季观赏价值的研究提供借鉴和参考。     

NaCl和壳聚糖对离体培养百里香精油的影响

采用水蒸气蒸馏法提取普通百里香(Thymus vulgaris L.)组培苗以及添加NaCl、壳聚糖的普通百里香组培苗的精油,利用气质联用法(GC-MS)结合色谱峰面积归一化法对其化学成分和相对百分含量进行比较研究.结果表明,3种组堵苗百里香精油都含有一般百里香精油的主要成分百里香酚、香芹酚、石竹烯等,化学成分的种类有...     

A comparison study on heavy metal/metalloid stabilization in Maozhou River sediment by five types of amendments

Purpose

River sediment pollution by heavy metals/metalloids has attracted widespread attention due to a serious threat to the ecosystem and human health. As an effective and economical alternative, the stabilization method was considered by previous studies for the remediation of sediments polluted by metals/metalloids. However, a comprehensive study is required for an extensive comparison on the effects of metal/metalloid immobilization based on the application of different materials as sediment amendments.

Materials and methods

In this study, the Maozhou River was selected as the study area, and the stabilization method was applied for the remediation of the river sediment polluted by metals and metalloids. Five materials (CaCO₃, Ca(OH)₂, zeolite, kaolin, FeCl₂) were selected as amendments for the metal/metalloid stabilization in the collected sediment. A modified BCR procedure was employed for the speciation analysis of heavy metals and metalloid in the sediment before and after remediation. A TCLP (toxicity characteristic leaching procedure) investigation was performed to further evaluate the immobilization of heavy metals in acidic environment.

Results and discussion

The sediment of the Maozhou River was heavily polluted by heavy metals and metalloid. The speciation of As, Pb, Cr, and Mn mainly exists as residual fraction (F4), while that of Ni, Cu, and Zn was identified as exchangeable metal and carbonate-associated fraction (F1) and fraction associated with Fe-Mn oxides (F2). Moreover, the F2 fraction of Co was observed as the major speciation. Through the application of five materials (CaCO₃, Ca(OH)₂, zeolite, kaolin, FeCl₂) as sediment amendments, the metal/metalloid speciation was transferred into F4. When five amendments were compared, the stabilization effect can be ordered as CaCO₃?>?zeolite?>?FeCl₂?>?kaolin?>?Ca(OH)₂ based on the modified BCR results. TCLP results showed that using Ca(OH)₂ and CaCO₃ as amendments can significantly reduce the metal leachability in an acidic environment, while zeolite is effective for most of the heavy metals and metalloid.

Conclusions

The results showed that the sediment of the Maozhou River was seriously polluted by a variety of heavy metals and metalloids. This study provided extensive information on the speciation of metals or metalloid and the effect of various amendments on metals and metalloid stabilization, which can be of vital importance for further remediation of metal/metalloid-polluted sediment.

     

Rheological Behaviour of Wheat Endosperm—Proposal for Classification Basedon the Rheological Characteristics of EndospermTest Samples

A simple, rapid method for the preparation of parallelepiped-shaped samples from a grain is used in the proposal of a study of the rheological behaviour of wheat endosperm. Compression rupture, creep and relaxation tests are used. A series of compression tests on mealy and vitreous endosperm of different wheat varieties (soft, hard and durum) shows that the rheological properties are influenced by both the genetic origin and grain vitreousness. The main mechanical characteristics—Young's modulus, elastic and rupture stresses, rupture energy and rupture strain—were determined at moisture contents of 12 to 17%. The influence of the moisture content on rheological behaviour is demonstrated. The vitreous endosperm of some wheat varieties displays considerable ductility before rupture. The nature of this plasticity was analysed by creep and relaxation tests on hard and soft wheats. Comparison of the different endosperm rheology values clarifies the notions of vitreousness and hardness. Wheat classification based on endosperm mechanical characteristics is proposed. It seems that Young's modulus characterises hardness whereas rupture energy is related to the vitreousness of the different varieties studied. Entering the results in a Young's modulus–rupture energy system leads to a classification of wheats according to two essential factors: hardness of varietal origin and vitreousness of cultural origin.     

日本落叶松体细胞胚胎发生的研究

[目的]对日本落叶松体细胞胚胎发生进行系统研究。[方法]以日本落叶松5个品种的未成熟合子胚为外植体,研究基本培养基、品种基因型、杂交系和纯系品种对日本落叶松愈伤组织诱导的影响,以及ABA对体细胞胚成熟及植株再生的影响。[结果]通过对日本落叶松胚性愈伤组织的诱导和体细胞胚的成熟培养获得再生植株。2种基本培养基中,DCR对胚性愈伤组织的诱导频率最高,达54.0%;落叶松品种之间的愈伤组织诱导率有差异,以杂交品种愈伤组织的诱导率最高,达71.4%,优于纯系的落叶松品种（27.3%～50.0%）;在体细胞胚的成熟培养过程中,ABA可严重影响体细胞胚的发育,并影响到其以后的萌发能力和植株再生。[结论]杂交品系更有利于胚性愈伤组织诱导,ABA对日本落叶松体细胞胚胎发育起重要作用。