Baseline assessment of metals and hydrocarbons in the sediments of Lake Mulwala, Australia

An assessment of hydrocarbon and metal/metalloids (arsenic, cadmium, copper, lead, mercury, selenium, zinc) contamination in sediments from Lake Mulwala, Australia, was undertaken. The objectives of the study were: (i) to determine the extent of contamination in the lake sediments, compared to Australian and international sediment quality guidelines, and (ii) to attempt to identify the contaminant sources to the lake. With the exception of a few samples containing elevated levels of arsenic and/or mercury, the levels of all contaminants in the sediment samples taken from the lake were below the ‘lower trigger’ of the Australian Sediment Quality Guidelines that would warrant further investigation. High molecular weight hydrocarbons (up to 700 mg kg⁻¹) were found in most sediment samples. Non‐metric statistical analysis indicated that the contaminant distribution was different in different parts of the lake, with the lowest concentrations generally found at the influent to the lake. No definitive source(s) of contamination could be identified for either metalloids or hydrocarbons.     

难熔金属与硬质材料进展─—从第十三届国际普兰西会议看发展动向（Ⅰ）

根据第十三届国际普兰西会议获得的信息，对国际上难熔金属、硬质合金、硬质材料和涂层技术等方面近几年来的研究和发展动态进行了综合评述。最后，提出了几点自己的看法。     

发泡金属的开发、性质及应用(Ⅰ)──发泡金属的制备方法

系统地综述了发泡金属的生产方法，包括铸造法、粉末冶金法、烧结法、沉积法和高压浸透法等。介绍了各种方法的特点及适用范围，指出了它们的优缺点及相应的改进措施，并对今后的发展方向提出了建议。     

Isotherm analyses for single component and multi-component metal sorption onto lignite

The adsorption of the three metal ions, copper, cadmium and zinc in single component and multi-component mixtures in aqueous solutions by lignite is reported. A comparison is made between the single component saturation uptake and the multi-component uptakes. The isotherms indicate a competitive uptake with copper being preferentially absorbed by the lignite in multi-component solutions. The isotherms are plotted to obtain the Langmuir constants, the Freundlich constants and the Redlich–Peterson constants. Lignite is shown to possess an affinity for the metal ions which make its use as an adsorbent a possible alternative to the use of more expensive activated carbons.     

Filler-induced failure mechanism in plastic-encapsulated microelectronic packages

Based on empirical data, the present work provides a model to prevent filler-induced reliability degradation in plastic-encapsulated LOC (lead-on-chip) packages. According to the model, the maximum size of the silica fillers included in the plastic package body should be smaller than one half of the inter-distance between the device and its overlying lead-frame. In particular, it is shown in the model that the spherical silica particles, which are sometimes trapped in the space between the top surface of the device and the bottom of the lead-frame during the encapsulating process, can induce huge compressive stress on a specific site of the integrated circuit pattern due to the thermal shrinkage of the plastic package body. Further, the present model suggests that tiny fillers squeezed beneath a large trapping filler might directly attack the brittle layer of the device pattern because the compressive force from the large filler particle can develop into huge compressive stress due to the reduced load-carrying area.     

把中国建设成世界有色金属制造业基地的对策研究

本文首先介绍了我国有色金属工业的现状以及当前世界有色金属工业发展的新格局,并分析了中国成为世界有色金属制造业基地的支撑条件,最后提出了关于建设具有特色的中国有色金属制造业基地的几点看法。     

Mechanical properties and thermal stability of rice husk ash filled epoxy foams

Mechanical properties and thermal stability of epoxy foams filled with white and black rice husk ash were studied. Epoxy foams were prepared from a commercial system and filled with different amounts of both the ashes (0, 6.8, 12.8, 18.0, and 22.7 wt %). The incorporation of both the ashes modified the final morphology of the foam, decreasing the average cell size and increasing the number of cells per volume unit. For all filler percentages used, the specific modulus and strength results showed that the white ash is more effective as reinforcing agent than the black ash. The initial degradation temperature was not affected by the content and type of ash used as the filler. The integral procedure decomposition temperature, weight loss, and char residue results were related to the ash type and atmosphere used in the thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Cover Picture: Programmable Motion and Separation of Single Magnetic Particles on Patterned Magnetic Surfaces (Adv. Mater. 14/2005)

Structured magnetic surfaces enabling programmable motion of single micrometer‐sized magnetic particles are reported on p. 1730 by Gunnarsson and co‐workers. Patterns of thin‐film magnetic elements are tailored to form transport lines with junctions for the separation of individual particles. This method has the potential to improve and generate new applications in biotechnology. The cover shows a schematic of the transportation and separation of magnetic particles functionalized with antibodies capable of selectively capturing the corresponding analytes from a sample.     

Electrokinetic remediation of soils contaminated with heavy metals

This paper describes the results obtained from an electrokinetic treatment of a real soil polluted by lead acetate. Powdered soil samples were pressed with a consolidometer till 100 kPa to obtain cylindrical specimens with the same characteristics as a subsoil. Tests were carried out in a Perspex electrochemical cell where soil specimens were introduced with a hollow punch. A low intensity direct current was applied in order to remove contaminants, due to electrophoresis and electroosmosis phenomena. The water flow, conductivity, apparent electroosmotic coefficient, as well as other characteristic parameters, were measured throughout the test. The water content and degree of pore saturation were estimated at the beginning and end of the test. The soil slab was divided into four slices and the Pb concentration profile determined. The main factor governing the extraction of contaminant was found to be the pH in the acidic range. Indeed, under these conditions high removal efficiencies could be reached. These results could lead to the design of a new electrochemical treatment cell equipped with a cationic membrane to expand the region of favourable pH within the soil.