Effects of heavy metals on plants and resistance mechanisms

Goal, Scope and Background. As one of the consequences of heavy metal pollution in soil, water and air, plants are contaminated by heavy metals in some parts of China. To understand the effects of heavy metals upon plants and the resistance mechanisms, would make it possible to use plants for cleaning and remediating heavy metal-polluted sites. Methods. The research results on the effects of heavy metals on plants and resistant mechanisms are compiled from Chinese publications from scientific journals and university journals, mostly published during the last decade. Results and Discussion. Effects of heavy metals on plants result in growth inhibition, structure damage, a decline of physiological and biochemical activities as well as of the function of plants. The effects and bioavailability of heavy metals depend on many factors, such as environmental conditions, pH, species of element, organic substances of the media and fertilization, plant species. But, there are also studies on plant resistance mechanisms to protect plants against the toxic effects of heavy metals such as combining heavy metals by proteins and expressing of detoxifying enzyme and nucleic acid, these mechanisms are integrated to protect the plants against injury by heavy metals. Conclusions. There are two aspects on the interaction of plants and heavy metals. On one hand, heavy metals show negative effects on plants. On the other hand, plants have their own resistance mechanisms against toxic effects and for detoxifying heavy metal pollution. Recommendations and Outlook. To study the effects of heavy metals on plants and mechanisms of resistance, one must select crop cultivars and/or plants for removing heavy metals from soil and water. More highly resistant plants can be selected especially for a remediation of the pollution site. The molecular mechanisms of resistance of plants to heavy metals should be studied further to develop the actual resistance of these plants to heavy metals. Understanding the bioavailability of heavy metals is advantageous for plant cultivation and phytoremediation. Decrease in the bioavailability to farmlands would reduce the accumulation of heavy metals in food. Alternatively, one could increase the bioavailability of plants to extract more heavy metals.

Investigation of a chemically treated InP(100) surface during hydrophilic wafer bonding process

Surface micro-roughness, surface chemical properties, and surface wettability are three important aspects of wafer surfaces during a wafer cleaning process, which determine the bonding quality of ordinary direct wafer bonding. In this study, InP wafers are divided into four groups and treated by different chemical processes. Subsequently, the characteristics of the treated InP surfaces are carefully studied by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurements. The optimal wafer treatment method for wafer bonding is determined by comparing the results of the processes as a whole. This optimization is later evaluated by a scanning electronic microscope (SEM), and the ridge waveguide 1.55 mu m Si-based InP/InGaAsP multi-quantum-well laser chips are also fabricated. (c) 2005 Elsevier B.V. All rights reserved.

含油污泥清洗剂的合成及其性能评价

含油污泥已作为危险废物列入《国家危险废物名录》（HW08），其处理问题已成为环保领域研究的热点。热洗技术是含油污泥处理的主流技术，而清洗药剂作为该技术的核心，直接影响含油污泥的处理指标与效率。目前，适合热洗处理的化学药剂很少，迫切需要开发专用药剂技术。针对含油污泥清洗效率的难题，本文合成了一种新型高效的含油污泥清洗剂。 本文以甲基丙烯酸（MAA）、丙烯酸丁酯（BA）和苯乙烯（St）为混合单体，偶氮二异丁腈（AIBN）为引发剂，通过溶液聚合的方法探索合成了一种高分子聚合物（命名为MBS）。分析讨论了MBS关键单体的选择、合成设计及方法，检测了MBS有关物理化学性能，考察了单体、引发剂用量及清洗条件对MBS脱油性能的影响，探讨了MBS对含油污泥中原油不同组分的去除效率，并用红外光谱证实了MBS结构的官能团。 MBS在单体质量比为MAA：BA：St=21：62：17，引发剂AIBN为单体总量的1.2%时，含油污泥脱油率可达84%以上。MBS对于含油污泥中芳烃去除率最高，为93.0%；其次是烷烃，去除率为87.4%；沥青质、胶质最低，去除率为71.8%，具有良好的处理效果。 本文还针对目前国内尚无评价含油污泥清洗剂的标准方法，对清洗剂性能评价进行了初探，采用统一标准的模拟含油污泥进行清洗剂性能评价，并提出了制备方法，同时验证了在此基础上所建立的性能评价方法。结果证明，模拟含油污泥能够真实体现清洗剂的脱油性能，所建立的评价方法可以作为一种通用规范的含油污泥清洗剂性能评价的基本方法。

典型粘土矿物吸附原油的清洗技术研究

含油污泥是危险废物，已列入《国家危险废物名录》。目前，热水清洗法是含油污泥处理的核心技术之一，但因含油污泥来源不同，成分性质各异，含油污泥清洗技术的普适性及规律性差。粘土矿物作为含油污泥泥质的主要成分，其吸附原油的清洗是含油污泥清洗技术的关键环节，因此，从粘土矿物性质、原油组分、清洗剂性质三个方面对粘土矿物吸附原油的清洗技术进行研究，分析其内在的规律性，是获得普适性含油污泥清洗技术的突破口。 本文结合含油污泥的理化性质分析，选取粒径范围为0～100µm高岭石、蒙脱石、绿泥石和伊利石四种粘土矿物，在优化工艺条件的基础上，研究其吸附原油在不同表面活性剂作用下的解吸规律，分析原油中不同族组分的脱附特性，筛选了针对典型粘土矿物吸附原油的高效清洗剂。 四种粘土矿物吸附原油解吸效率的大小顺序为伊利石>蒙脱石>高岭石>绿泥石。不同表面活性剂对粘土矿物吸附原油清洗效率的大小顺序为阴离子表面活性剂>非离子表面活性剂>阳离子表面活性剂。粘土矿物吸附原油中三个族组分的脱附难易顺序为饱和烃>芳烃>胶质沥青质，饱和烃的脱附效率是控制粘土矿物吸附原油总体清洗效率的最重要参数。Dodec-MNS和NPS-10是良好的粘土矿物吸附原油清洗剂，NPS–10对含油率为18.32%和29.68%的含油污泥的脱附效率分别为78.43%和84.11%。 本文同时还针对含油污泥清洗技术中清洗剂复配，提出根据含油污泥族组分特性，选取亲油基性质与对应族组分性质接近的表面活性剂进行复配的方法，方法经实验验证可行，可作为一种含油污泥清洗剂复配的基本方法。

Wettability designing by ZnO periodical surface textures

A facile and effective aqueous chemical synthesis approach towards well control of periodical ZnO textures in large-scale areas is reported, by which considerable adjusting of surface wettability can be realized. With the assistance of polystyrene spheres monolayer template and morphology control agent, we succeeded in preparing a series of ordered ZnO microbowls with different sag height. It was found that the contact angle could be well adjusted by changing geometry of microbowl. Such novel, ordered arrays are expected to exploit the great potentiality in waterproof or self-cleaning micro/nanodevices, and even microfluidic devices. (C) 2010 Elsevier Inc. All rights reserved.

非豆科固氮树种沙棘与微生物联合共生体的纯培养研究

Symbiosis between Frankia,VA mycorrhizal fungi and Hippophae rhamnoides L.was studied in lab.The characteristic structures-arbuscules of VAM and nodules were confirmed in the root of H.rhamnoides L.,which was inoculated with VAMF and Frankia in pure artificial culture.Evaluated by the stimulation on the growth of the host plant,VAH is a better associated fungi and HR16 is a better Frankia for Hippophae rhamnoides L.

Introduction to Molecular Analysis of Ectomycorrhizal Communities

A number of methods are available for those researchers considering the addition of molecular analyses of ectomycorrhizal (EcM) fungi to their research projects and weighing the various approaches they might take. Analyzing natural EcM fungal communities has traditionally been a highly skilled, time-consuming process relying heavily on exacting morphological characterization of EcM root tips. Increasingly powerful molecular methods for analyzing EcM communities make this area of research available to a much wider range of researchers. Ecologists can gain from the body of work characterizing EcM while avoiding the requirement for exceptional expertise by carefully combining elements of traditional methods with the more recent molecular approaches. A cursory morphological analysis can yield a traditional quantification of EcM fungi based on tip numbers, a unit with functional and historical significance. Ectomycorrhizal root DNA extracts may then be analyzed with molecular methods widely used for characterizing microbiota. These range from methods applicable only to the simple mixes resulting from careful morphotyping, to community-oriented methods that identify many types in mixed samples as well as provide an estimate of their relative abundances. Extramatrical hyphae in bulk soil can also be more effectively studied, extending characterization of EcM fungal communities beyond the rhizoplane. The trend toward techniques permitting larger sample sets without prohibitive labor and time requirements will also permit us to more frequently address the issues of spatial and temporal variability and better characterize the roles of EcM fungi at multiple scales.

石油污染土壤的生物修复技术

The soil contaminated by petroleum hydrocarbons and main methods of cleaning the pollutants were dealt with in the paper.The key principles,technological types, effect factors ,consolidation of the technology,present situation and development of the bioremediation of the soil contaminated by petroleum hydrocarbons were presented.

Processamento minimo de couve.

2000

Inspection of teats by colour image analysis for automatic milking systems

C.R. Bull, N.J.B. McFarlane, R. Zwiggelaar, C.J. Allen and T.T. Mottram, 'Inspection of teats by colour image analysis for automatic milking systems', Computers and Electronics in Agriculture 15 (1), 15-26 (1996)

Developing organisational change capability

Oxtoby, B.; McGuinness, T.; and Morgan, R. (2002). Developing organisational change capability. European Management Journal. 20(3), pp.310-320 RAE2008