Evaluation of Hard Coating Performance in Drilling Compacted Graphite Iron (CGI)

The aim of this investigation was to compare the performance of the following commercial coatings system, TiAlN/TiN, AlCrN, and TiSiN/AlCrN, deposited in cemented carbide tools in drilling compact graphite iron (CGI). The drilling tests were conducted adopting two cutting speeds: 80 or 150 m/min. For each test condition, the tool flank wear, the machining feed force, and the circularity and the roughness of the resulting drilled hole were determined. At the cutting speed of 80 m/min, the results revealed that the tool life, in terms of flank wear, was improved for the Cr-based coatings, while the multilayered coatings presented a better performance at the cutting speed of 150 m/min. It was also found that feed force is substantially increased when drilling at a cutting speed of 150 m/min. The holes drilled with the TiSiN/AlCrN at a cutting speed of 150 m/min showed the best circularity. The drill roughness is directly influenced by the coating system wear and iron adhesion. Consequently, it was found that the lowest holes’ roughness was obtained with TiSiN/AlCrN at 80 m/min.     

Enantiomeric Anosmia in Scarab Beetles

The sex pheromone for Anomala octiescostata has been previously identified as a 4:1 mixture of (R)-buibuilactone and (R)-japonilure. Field experiments showed that although not active per se, the secondary component increased the activity of major component, buibuilactone. The enantiomers of these semiochemicals, i.e., (S)-buibuilactone and (S)-japonilure are neither attractants nor behavioral antagonists to the pheromone system of A. octiescostata. Chiral GC-EAD experiments demonstrated that, in marked contrast to the Japanese beetle and Osaka beetle, which can detect a stereoisomer not produced by their conspecific females, the male antennae of A. octiescostata lack olfactory receptor neurons (ORNs) tuned to (S)-buibuilactone. The same enantiomeric anosmia (inability to smell a compound) was also observed in Anomala cuprea male antennae. Both in a Y-olfactometer and field experiments, it was clarified that (S)-buibuilactone was not a behavioral antagonist for A. cuprea. Contrary to male antennae of both A. octiescostata and A. cuprea, which lack ORNs tuned to the nonnatural (S)-buibuilactone, fragrance evaluation by skilled perfumers revealed that the human nose can discriminate (both in intensity and quality) enantiomerically pure samples of (R)- and (S)-buibuilactone and japonilure.     

AZ91D镁合金的触变成形及其磨损性能的研究

研究了加热时间和模具预热温度对AZ91D镁合金触变成形性、组织和磨损性能的影响。结果表明，适合AZ91D镁合金触变成形的最佳加热时间为90min(在585℃)，模具预热温度为350℃；在此工艺条件下，初生相颗粒较圆整、粒度较小，组织最致密，相应地，其耐磨性也最好；与金属型铸造相比，触变成形显著地减少了缩松，因而，也明显地提高了耐磨性。     

2011年中国氯碱行业现状分析

分析了中国氯碱行业产能、产量、供需、市场等方面的现状以及影响因素。分析结果表明氯碱产能呈现有退有进的新特点,工艺技术更新换代进程加快,政策环境影响更加深入并将常态化。     

煤沥青的改性研究进展

介绍了传统的煤沥青改性方法,综合概述了国内外对煤沥青的流变性、结焦性、中间相的形成以及煤沥青对石油焦的润湿性和渗透性等方面的研究进展,进一步介绍了环保沥青方面的研究现状。在此基础上对煤沥青的改性研究前景进行了展望。     

Determination of Essential Fatty Acids in Captured and Farmed Matrinxã (<Emphasis Type="Italic">Brycon cephalus</Emphasis>) from the Brazilian Amazonian Area

The aim of this research was to quantify the methyl esters of linoleic (LA), α-linolenic (LNA), arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids in the muscular tissue and orbital cavity of farmed Matrinxã (Brycon cephalus) and in those caught in the Brazilian Amazonian Area during two periods. For the farmed fish, the amounts (mg/g of fat) of LA, LNA, AA, EPA, and DHA found in the muscle were 197.6, 75.7, 165.0, 4.1, and 30.0 mg/g of fat, respectively. The amounts of these FA in the orbital cavity were 152.6, 9.1, 249.4, 3.6, and 22.3 mg/g of fat for LA, LNA, AA, EPA, and DHA, respectively. For the fish caught during the wet period, the LA, LNA, AA, EPA, and DHA found in the muscle were 438.2, 118.3, 42.7, 5.2, and 10.3 mg/g of fat, in the orbital cavity were found 489.1, 18.6, 18.1, 6.2, and 18.7 mg/g of fat, respectively. In the dry season, the amounts (mg/g of fat) of LA, LNA, AA, EPA, and DHA in the muscle were 193.1, 40.0, 43.4, 8.1, and 61.3, while the found in the orbital cavity were 152.9, 28.4, 5.1, 4.9, 19.6 mg/g of fat. According to their contents of EPA, and DHA, matrinxã captured in the dry season can be considered as a rich source of EFA.     

Investigation of nitrogen addition on hydrogen incorporation in CVD diamond films from polycrystalline to nanocrystalline

The effect of nitrogen addition in the gas phase on hydrogen impurity incorporation into CVD diamond films was investigated. A series of thick diamond films of different morphology and quality ranging from large-grained polycrystalline to fine-grained nanocrystalline were deposited on silicon wafers using a 5 kW microwave plasma assisted CVD system. They were obtained only by changing the small amount of oxygen and nitrogen addition while keeping all other input parameters the same. Bonded hydrogen impurity in these diamond films was studied by using Fourier-transform infrared spectroscopy. It was found that with increasing the amount of nitrogen addition in the gas phase, the produced diamond films from large-grained polycrystalline gradually shift to fine-grained nanocrystalline and their crystalline quality is drastically degraded, while the amount of incorporated hydrogen impurity in the diamond films increases sharply. The role of nitrogen additive on diamond growth and hydrogen incorporation is discussed. These results shed light into the growth mechanism of CVD diamond films ranging from polycrystalline to nanocrystalline, and the incorporation mechanism of hydrogen impurity in CVD diamonds.     

Electrical conductivity of polystyrene/styrene-butadiene block copolymer blends containing carbon black

The electrical resistivity and mechanical properties of carbon black (CB)-filled polystyrene (PS)/styrene-butadiene block copolymer (SB) blends have been studied. Good electrical performance was achieved with pure SB and PS/SB blends indicating an inhomogeneity of these materials and the heterogeneous micro-dispersion of the CB particles. The percolation threshold of the filler inside SB or PS/SB blends is around 3.6 wt%, which is lower than that expected for incompatible PS/PBD blend. The addition of small amount CB decreases the elongation at break of PS/SB blends indicating some disturbance at the interface of these compatible material. Received: 28 July 1996/Revised version: 1 October 1996/Accepted: 3 October 1996     

Preparation of epoxy/MCDEA networks modified with ionic liquids

Ionic liquids based on imidazolium, pyridinium and phosphonium with long alkyl chain were used to develop epoxy networked materials cured at high temperature, with 4,4′-methylene-bis 3-chloro-2,6-diethylaniline (MCDEA). Imidazolium- and pyridinium-based ILs decreased the onset curing temperature suggesting an accelerating effect, whereas those based on phosphonium salts exerted only a marginal effect on the curing process. The presence of the ILs resulted in a decrease of the glass transition temperature and this effect was less pronounced in systems containing phosphonium-based IL with [PF₆] as the counteranion. The storage modulus below the Tg increased with the addition of ionic liquid suggesting an improvement of stiffness due to the interactions between the ILs and the epoxy matrix. Such interactions were also confirmed by rheological properties. Considering different ionic liquids, those constituted by phosphonium salts were effectively confined inside the epoxy networks and that containing iodide as the counteranion presented the best thermal stability, being indicated for assessing epoxy-based systems with high curing temperature.     

Supercritical CO2-assisted preparation of a PMMA composite membrane for bisphenol A recognition in aqueous environment

This work reports a novel strategy to prepare affinity composite membranes using supercritical fluid technology. By blending molecularly imprinted polymeric particles with PMMA, a porous hybrid structure with affinity to the template molecule, bisphenol A, was prepared using a supercritical carbon dioxide (scCO₂)-assisted method. Membranes were characterized in terms of morphology, mechanical performance and transport properties. The ability of the polymers and hybrid membranes to adsorb bisphenol A was tested in aqueous solutions and fitted to a linearized Langmuir equation, showing that adsorption takes place at homogeneous affinity binding sites within the imprinted surface. Filtration experiments showed that the imprinted hybrid membrane was able to adsorb higher amounts of template even in non-equilibrium dynamic binding conditions. The hybridization of the PMMA membrane herein reported conveys two important improvements over neat PMMA membrane: it introduced molecular affinity towards the template molecule and significantly increased the permeability of the porous structures, which are key parameters in processes that involve membranes. This technique could expand the applications of polymeric beads powders and enhance the efficiency of the membrane's transport properties. Our work presents a new method to confer affinity to a porous structure by immobilization of imprinted polymers, combining polymer synthesis and membrane formation using supercritical fluid technology.