我国贵金属废料回收产业发展综述

分析了贵金属回收利用具有良好的经济效益，国内外对这项工作极为重视，并取得了佳绩。同时，总结了废旧贵金属的主要来源，以及回收新技术。指出，我国废旧贵金属回收体系不够健全，亟待政策扶持。     

Studies of deformation-induced texture development in sheet materials using diffraction techniques

Crystallographic texture measurements were made on a series of rolled aluminum sheet specimens deformed in equi-biaxial tension up to a strain level of 0.11. The measurement techniques used were neutron diffraction with a 4-circle goniometer, electron backscatter diffraction, conventional powder X-ray diffraction (XRD), and XRD using an area detector. Results indicated a complex texture orientation distribution function which altered in response to the applied plastic deformation. Increased deformation caused the {1 1 0} planes, to align parallel to the plane of the sheet. The different techniques produced results that were very consistent with each other. The advantages and disadvantages of the various methods are discussed, with particular consideration of the time taken for each method, the range of orientation space accessible, the density of data that can be obtained, and the statistical significance of each data set with respect to rolled sheet product.     

Recent Advances in Disordered and Nanostructured Carbon Coatings for Superl Ubricity and Wearless Sliding

Increasingly more demanding and very stringent operating conditions envisioned for future mechanical and tribological systems will certainly require new materials and coatings that are superhard and at the same time self-lubricating.For example, dry machining is a much desired practice in manufacturing sector, but it is currently very difficult to realize mainly because of high friction and severe wear losses. However, recent advances in surface engineering and coating technologies may enable design and production of novel coatings architectures that can combine superhardness with self-lubricating properties in both the disordered or nanostructured forms. Recently developed nearly frictionless carbon films, ultrananocrystalline diamond and carbide derived carbon films can dramatically lower friction and at the same time reduce wear under very harsh sliding conditions. These coatings can be formulated in such a way that they can substantially increase the load-bearing capacity of sliding surfaces and hence improve their resistance to scuffing. It is also possible to design nano-composite coatings that can form self-replenishing and-lubricating tribofilms on their sliding surfaces and thus help increase the overall lubricity of these surfaces. In this paper, an overview of recent advances in disordered and nanostructured carbon films will be presented. Specific examples will be given to demonstrate the superior performance and durability of such novel coatings under a very wide range of tribological conditions. The major emphasis is placed on super low friction carbon films. The fundamental tribological mechanisms that control their exceptional friction and wear behaviors are also discussed.     

An Analytical Equation of State for Alkaline Earth Metals

In this work, an analytical equation of state based on statistical mechanical perturbation theory, which was initially developed for normal fluids and can be applied to predict the P–V–T data for saturated liquid alkaline earth metals, is presented. The equation of state is that of Ihm, Song, and Mason, and the temperature-dependent parameters of the equation of state are calculated from a corresponding-states correlation as functions of the reduced temperature. Two scaling constants are sufficient for this purpose, the surface tension and the liquid density at the melting point. The equation of state is used to predict the saturated liquid density of molten alkaline earth metals from the melting point up to 2000 K, for which experimental data exist, within an accuracy of 5%.     

Lead Extraction from Contaminated Soil Using Water-Soluble Polymers

The applicability of water-soluble polymers as extractants for the remediation of heavy metal-contaminated soils has been explored using a lead-contaminated Superfund soil as a sample system. Polyethylenimine (PEI) was functionalized with bromo- or chloroacetic acid to give an aminocarboxylate chelating group, which effectively binds lead. The resulting polymer, PEIC, has extraction properties similar to the molecular chelator ethylenediaminetetraacetic acid. A series of studies was done to probe optimum conditions for lead extraction from soils obtained from the Cal-West Superfund site in New Mexico that contained approximately 10,000 ppm of Pb. In batch extraction experiments using polymer functionalized at two different levels, the polymers removed greater than 97% of the lead from the soils. Subsequent experiments demonstrated that the selective extraction of lead could be controlled by varying polymer functionalization levels. Concentration and regeneration of the polymers using ultrafiltration was also demonstrated. Release of lead from the polymer was accomplished by acidification to pH 1 with HCl. Subsequent ultrafiltration allowed recovery of the extractant polymer for reuse.     

珠江三角洲典型区域土壤重金属污染探查研究

以珠江三角洲典型区域研究高强度经济开发下土壤环境中重金属污染的状况。测定了84份样品中铜、锌、镉、铬、铅的含量水平。土壤中镉、铬、铅、镍、铜、锌的含量分别在0.166～0.433mgkg-1、2.28～94.28mgkg-1、20.36～143.3mgkg-1、2.29～63.55mgkg-1、4.8～65.1mgkg-1、10.06～131mgkg-1之间。从分析结果可以看出,镍、铅等元素在有些地方普遍偏高,且有的极为明显,已高出背景值108.3mgkg-1。其他元素也存在不同水平的富集,普遍高出背景值。     

Mg6Si4O10(OH)8修复剂应用于滑动轴承的模拟试验研究

采用模拟轴承试验机,考察在设计的试验条件下金属磨损自修复层在45#钢/巴氏合金摩擦副间的原位生成及其摩擦学性能。润滑剂使用含适量Mg6Si4O10(OH)8修复剂的SD/CC 40汽油机/柴油机通用油。27 h摩擦试验结束后,采用表面形貌仪、扫描电镜和显微硬度计分析摩擦表面。结果表明,在45#钢表面形成了约2μm厚的自修复层,2个摩擦副表面的表面形貌均有明显改善;显微硬度均有一定的提高,金属磨损自修复层表现出优良的抗磨粒磨损和抗粘着磨损的性能。     

Construction and in vitro/in vivo evaluation of 17-allylamino-17-demethoxygeldanamycin (17AAG)-loaded PEGylated nanostructured lipid carriers

In this study, the PEGylated nanostructured lipid carriers (PEG-NLC) were constructed for the intravenous delivery of 17-allylamino-17-demethoxygeldanamycin (17AAG). 17AAG-PEG-NLC was successfully prepared by the method of emulsion evaporation at a high temperature and solidification at a low temperature using a mixture of glycerol monostearate and PEG₂₀₀₀-stearate as solid lipids, and medium-chain triglyceride as the liquid lipid. The results revealed that the morphology of the NLC was spheroidal. The particle size, zeta potential and entrapment efficiency for 17AAG-PEG-NLC were observed as 189.4?nm, ?20.2 mV and 83.42%, respectively. X-ray diffraction analysis revealed that 17AAG existed as amorphous structures in the nanoparticles. In the in vitro release study, the 17AAG from 17AAG-PEG-NLC exhibited a biphasic release pattern with burst release initially and sustained release afterwards. In addition, 17AAG-PEG-NLC showed a significantly higher in vitro antitumor efficacy and longer retention time in vivo than 17AAG solution. These results indicated that 17AAG-PEG-NLC may offer a promising alternative to the current 17AAG formulations for the treatment of solid tumors.     

Influence of surface oxidation on electric potential measurements in MHD liquid metal flows

Experimental investigations for magnetohydrodynamic flows in rectangular ducts are performed using GaInSn as model fluid. Measurements of electric potential on channel walls and inside the flow show reproducible discrepancies compared to analytical results. These discrepancies can be ascribed to the formation of oxide layers causing a contact resistance between the electrically conducting duct walls and the liquid metal. An exact analytical solution for pressure drop, velocity and potential distributions has been derived taking into account the presence of a contact resistance. Analytical results for velocity and potential profiles and for pressure drop are discussed for different values of contact resistance and strength of the applied magnetic field. A comparison of measured potential with data from the analytical solution allows estimating the order of magnitude of the contact resistance in the present experiments.     

污泥炭田间老化对土壤重金属及养分的影响

污泥基生物炭内源重金属和养分含量因污泥来源的不同而差异较大。为探索污泥基生物炭“还田”后，其内源重金属变化和养分的去向问题，采用干湿交替对污泥基生物炭模拟老化处理，分析老化前后污泥基生物炭的Cu、Zn金属形态及TCLP浸出毒性的变化；研究污泥基生物炭BC1和BC2（分别以磷酸二氢钾、磷酸二氢钙与污泥混合后热解制备的生物炭）以5%和10%的质量分数与鲜土混合老化后对污泥基生物炭内源重金属稳定性及土壤有机碳和有效磷含量变化的影响。结果表明：两种污泥基生物炭与土壤混合老化后会使土壤中SiO2含量增加，但不会改变土壤的吸附类型；污泥基生物炭的添加会增加土壤的比表面积，其中BC2增幅较大，为36.17 m2/g；施加两种污泥基生物炭土壤中Cu、Zn生物有效性均有不同程度的降低。TCLP浸出毒性量相比老化前降低（BC1约降低37.5%）。此外，BC1对土壤有效磷的提升效果优于BC2（BC1 70 mg/kg，BC2 30 mg/kg）；BC2对土壤有机碳的提升效果优于BC1（BC2 2.2%，BC1 1.15%）。BC2还田更有利于Cu、Zn的固定以及土壤有机碳和有效磷的提升。