腰果壳液改性胺固化无溶剂环氧底漆的特性研究

腰果壳液改性胺是一种新型环氧树脂固化剂,市场反映良好。对其固化性质作了进一步的探索,主要通过表干时间、附着力、剪切强度以及适用期的测试,研究腰果壳液改性酚醛胺类固化剂及其复配体系对无溶剂环氧底漆的固化特性。实验结果表明,腰果酚醛胺类固化剂在保持优异的附着力和剪切强度的情况下,提高了固化速度,是一种综合性能优异的固化剂。     

A review of the IEA/NEA Projected Costs of Electricity – 2015 edition

The IEA/NEA recently issued their eighth edition of the Study on the “Projected Costs of Generating Electricity” – 2015 edition. The Study is mainly concerned with calculating the levelised cost of electricity (LCOE). The LCOE calculations are based on a levelised average life time cost approach using the discounted cash flow (DCF) method. The analysis was this year, and for the first time, performed using three discount rates (3%, 7%, and 10%). The LCOE can serve as a tool for calculating the cost of different generation technologies. However the Study's usefulness is affected by its narrow base of a limited set of countries that are not necessarily representative. It ignored the negative role of subsidies and did not provide a methodology for selective application of the discount rates and costing of carbon. The global power generation scene is changing. Generation growth in OECD countries has become very limited; simultaneously there is rapid growth of varying renewables (VRE) generation which needs special criteria for assessing its system cost. All this demands a rethinking of the application and usefulness of the LCOE in future generation planning.     

气相色谱法测定婴幼儿配方乳粉中的OPO含量

建立气相色谱法测定婴幼儿配方乳粉中OPO的含量。乳粉中的油脂经乙醚与石油醚萃取后,通过旋转蒸发浓缩,以十七烷酸甘油三酯为内标物。利用带有FID检测器的气相色谱仪对其中的OPO含量进行测定分析,并对色谱条件优化。优化后OPO的线性范围为0.1~0.5 g/100 g,相关性R^2为0.9998。检出限为0.04 g/100 g,定量限为0.14g/100 g。当加标浓度为2.4~4.4 g时,加标回收率为92.97%±5%,相对标准偏差RSD为2.57%(N=6)。该方法可靠、简便,可准确测定婴幼儿配方乳粉中OPO含量。     

Effects of different physical technology on compositions and characteristics of bean dregs

The effects of ultrafine grinding (U), high pressure (HP), microwaves (M), high-temperature cooking (HTC) and combination technologies (U-HP, U-M, U-HTC) on the nutritional compositions and characteristics of bean dregs were investigated. The results showed that both single treatments and combination treatments significantly increased the soluble dietary fiber (SDF) content and water solubility of bean dregs; however, the protein content, fat absorption capacity and swelling capacity of bean dregs were decreased compared with those of the control. The combination technologies significantly increased the contents of K, Ca, Na and Fe in bean dregs. HTC and U-HTC had prominent effects on inhibiting trypsin inhibitor activity, which were decreased from 7365 TIU/g to 1210 and 96 TIU/g, respectively. The bean dregs by ultrafine grinding and combined treatments showed honeycomb structure and small particle distribution, and their processing performances improved. In conclusion, combination technologies were effective methods for improving the quality of bean dregs and expanding their development.Industrial relevance: A combined method may have greater effects than any single approach in improving the quality of bean dregs. Ultrafine grinding technology combined with other physical techniques used in bean dregs can solve quality problems; for example, bean dregs are characterized by poor taste, perishability, low soluble fiber content, and high trypsin inhibitor activity, all of which are related to human health and safety. However, to the best of our knowledge, ultrafine grinding combined with other physical techniques has not been used with bean dregs. The present paper highlights the effects of ultrafine grinding technology (U) combined with high pressure (HP), microwave (M), and high temperature cooking (HTC) technologies on the nutritional and functional compositions of bean dregs. The obtained results contribute to enhance SDF content, reduce anti-nutrition factors, and expand development and utilization of bean dregs, which constitute the basis for its application in baked food, flour products and the food industry.     

乳品分析中容器对痕量金属离子吸附作用的研究

金属离子在分析容器上的吸附特性,可能导致痕量金属分析产生误差,了解和掌握误差来源是避免和减少分析误差的重要途径。用原子吸收光谱法,对酸度、浓度、温度和金属价态对Mg2+,Fe3+和Cr6+离子在玻璃容器表面上的吸附行为的影响进行了研究。结果表明,溶液的酸度、离子的初始浓度、金属溶液的贮存环境对玻璃容器表面的吸附性能都有影响,Mg2+,Fe3+和Cr6+的溶液酸度质量浓度越高、贮存温度越低,容器对离子的吸附率越低;价态不同吸附性能也明显不同,Mg2+在玻璃容器的吸附性最大。     

A partial sulfidation approach that significantly enhance the activity of FeCo layered double hydroxide for oxygen evolution reaction

We report a partial sulfidation approach that effectively boosts the OER activity of FeCo-layered double hydroxides (LDH). It is found that the mild sulfurized FeCo-LDH nanosheets using Na₂S converted a portion of their surface metal-hydroxide bonds to metal-sulfur (-hydrosulfide) bonds without significantly altering their crystal structure. The sulfidation degree is controlled by Na₂S concentration for obtaining a moderately surface electronic configurations. Benefits from the regulated electronic configurations, the sulfurized FeCo-LDH nanosheets only require an overpotential of 281 mV to produce oxygen at 10 mA cm⁻² and their Tafel slope is 51.8 mV dec⁻¹, which are both lower than the 348 mV and 72.7 mV dec⁻¹ of pristine FeCo-LDH nanosheets. The sulfurized catalysts have sustained 12 h of operation without notable activity loss. This work can provide new insights into understanding the roles of metal-sulfur bonds for OER and offer an attractive strategy to design low cost but efficient OER catalysts.     

Hydrogen production from glucose by a mutant strain of Rhodovulum sulfidophilum P5 in single-stage photofermentation

Single-stage hydrogen production from glucose was investigated using the marine photosynthetic bacterium Rhodovulum sulfidophilum TH-79, a Tn7 transposon mutant of strain P5. The mutation in strain TH-79 did not affect its cell growth in glucose medium compared with the parent strain. TH-79 displayed improved photoheterotrophic hydrogen production performance when the medium contained glucose or galactose as the sole carbon source. The mutant produced about 7.07 mol H₂/mol glucose, which is similar to the yields of more complicated integration systems. A one-stage photofermentation system using a seawater culture medium appears to be a promising alternative to the integration of dark- and photofermentation systems.     

pH值对剩余污泥中氮、磷溶出及菌群组成的影响

为了研究剩余污泥水解酸化过程中氮、磷的溶出规律及菌群组成,分别控制p H值为5~12及不调节,测定各条件下溶出的NH+4-N和PO3-4-P浓度,并采用PCR-DGGE技术分析剩余污泥中的菌群组成。结果表明:对剩余污泥的p H值进行调节,能够提高氮、磷的溶出量,且p H值为9~11条件下的NH+4-N溶出量远高于其他条件下的。与NH+4-N的溶出不同,酸性条件更有利于PO3-4-P的溶出。不同污泥样品具有不同的DGGE指纹图谱特征,即菌群组成不同,这在一定程度上影响着剩余污泥水解酸化过程中氮、磷的溶出。     

Model calculations of electric forces acting on carbon nanotube tip in DC-plasma sheath

Numerous ·experimental investigations indicate the necessity of negative bias for low-pressure CVD of aligned carbon nanotubes. Based on the experimentally determined electron density in the dual hot filament/DC plasma deposition system the electrical field close to the substrate was calculated. Taking into account the field enhancement in the vicinity of the CNTs the force acting on their tips is determined. The calculated force has been found to exceed the weight of the droplet by four orders of magnitude. The computations have shown only a weak dependence between the electrical forces and the droplet shape.     

Establishment of bioenergy crops on metal contaminated soils stimulates belowground fauna

Soils of contaminated agrosystems represent potential arable land surfaces for the production of non-alimentary crops. The aim of this study is to monitor changes in belowground biodiversity (Collembola), potentially occurring following establishment of perennial biomass crop systems on contaminated agricultural land. We selected, within an agricultural trial, two different biomass crops, miscanthus (Miscanthus x giganteus) and switchgrass (Panicum virgatum) and an annual wheat crop (Triticum sp.) used as a control. About 20-fold more individuals were found under miscanthus and switchgrass than under wheat. The highest mean number of species was found under miscanthus being 30% greater than in switchgrass and 424% than in annual wheat. Furthermore, abundance and species richness of the three collembolan life-forms (epedaphic, hemiedaphic, and euedaphic) differed between the crops leading to distinctly different assemblages.On metal contaminated soils, perennial bioenergy crops have the potential to increase belowground faunal diversity and abundance with the identity of crops as a critical factor driving soil animal assemblages.