Springer basic sets and modular Springer correspondence for classical types

We define the notion of basic set data for finite groups (building on the notion of basic set, but including an order on the irreducible characters as part of the structure), and we prove that the Springer correspondence provides basic set data for Weyl groups. Then we use this to determine explicitly the modular Springer correspondence for classical types (defined over a base field of odd characteristic $p$, and with coefficients in a field of odd characteristic $?\ne p$): the modular case is obtained as a restriction of the ordinary case to a basic set. In order to do so, we compare the order on bipartitions introduced by Dipper and James with the order induced by the Springer correspondence. We provide a quick proof, by sorting characters according to the dimension of the corresponding Springer fibre, an invariant which is directly computable from symbols.     

Reciprocating sliding wear behavior of laser-clad small amplitude Mo2Ni3Si/NiSi metal silicide composite coatings

Mo₂Ni₃Si/NiSi metal silicide composite coatings with a fine microstructure consisting of Mo₂Ni₃Si primary dendrites and the interdendritic Mo₂Ni₃Si/NiSi eutectics were fabricated on austenitic stainless steel AISI 321 by laser cladding process. Small amplitude reciprocating sliding wear resistance of the coatings is evaluated as functions of normal load and slip amplitude and the wear mechanisms were discussed based on worn surface morphology observations. Results showed that the Mo₂Ni₃Si/NiSi coatings have excellent small amplitude reciprocating sliding wear resistance.     

Microstructure and high-temperature wear resistance of a laser surface alloyed γ-TiAl with carbon

TiC reinforced composite coating on γ-TiAl alloy was successfully fabricated by laser surface alloying with carbon. The fine TiC reinforcing phase had a gradient distribution in the coating, and its growth morphology of TiC in laser surface alloyed coating was in unique faceted platelet-like. The composite coating exhibited high hardness and excellent high-temperature sliding wear resistance.     

Front roughening in three-dimensional imbibition

We investigate the structure and dynamics of the interface between two immiscible liquids in a three-dimensional disordered porous medium. We apply a phase-field model that includes explicitly disorder and discuss both spontaneous and forced imbibition. The structure of the interface is dominated by a length scale ξ_× which arises from liquid conservation. We further show that disorder in the capillary and permeability act on different length scales and give rise to different scalings and structures of the interface properties. We conclude with a range of applications.     

The Fundamental Experiments of Red Tide Chemical Forecast

Many food algae and red tide algae were cultivated in the f/2 medium, and the nitric oxide (NO) concentration of the medium and the cell density were determined. The experiments on algae were conducted when different concentrations of NO were added into the medium using two methods. The results show that low concentrations of NO were self-produced by marine algae during the exponential growth period and were about nmol/L level. But at the end of the period, i.e., 2 or 3 days before the cell density reaches the maximum, an NO peak appeared, with the NO concentration reaching 10 nmol/L. The NO threshold concentration exists according to the influence of exogenous NO on the marine phytoplankton growth. One type is the threshold concentration that can promote algae growth, and its value is between 10 and 1 nmol level, or even lower. The other type can inhibit the phytoplankton growth, which is about μmol level or higher. The results indicate that red tide algae are far more sensitive to NO than are food algae. The fundamental experimental outcome above may provide a new clue for red tide chemical forecast by inspecting the NO change.     

柴油烃族组成分布的GC-MS测定

应用GC－MS测定柴油烃族组成按沸点的分布，通过柱色 谱分离后的柴油饱和烃和芳烃组分分别进入气相色谱－质谱联用仪分析，采集其每一扫描的质谱图后，按ASTM－D2425方法计算其每一扫描的烃族组成，因为每一扫描与保留时间对应，所以可将两部分烃族组成加和后应用ASTM－D2887方法计算柴油烃族组成按沸点的分布规律；实验结果表明，该法与ASTM－D2887和ASTM－D2425的实验结果吻合，并能给出有关柴油烃族组成的详尽分布规律。     

龋病人牙釉质表面硬度及抗磨损性能测试

采用人工方法制成人牙釉质浅龋及使用抗龋措施的龋损釉质样本，分别测量各组釉质表面显微硬度，并以微动摩擦磨损试验机测试其抗磨性能，试验结果表明：各组实验组釉质较对照组表面硬度都有不同程度下降，氟化钠前处理会使釉质表达硬度显著下降，人工浅龋牙釉质的抗磨损性能不如正常釉质，使用两种抗龋措施对其抗磨性能没有明显改善。     

稀土变质热锻模具铸钢高温磨损性能的研究

研究了稀土（RE）变质热锻模具铸钢的高温磨损性能，并与热锻模具钢H13钢和3Cr2W8V钢进行对比，探讨了稀土元素的作用和热锻模具铸钢的高温磨损机理。结果表明：随着RE加入量的增加，热锻模具铸钢的磨损率先减后增，RE加入量在质量分数为0．05％时热锻模具铸钢具有最佳的高温磨损性能。RE变质热锻模其铸钢的高温耐磨性明最高于H13钢和3Cr2W8V钢。高温磨损机理为氧化磨损和氧化物的疲劳剥落，磨屑为块状的Fe2O3和Fe3O4。     

Effect of electrolytes on the surface behavior of rhamnolipids R1 and R2

The surface behavior of solutions of the rhamnolipids, R1 and R2, were investigated in the absence and presence of an electrolyte (NaCl) through surface tension measurements and optical microscopy at pH 6.8. The NaCl concentrations studied are 0.05, 0.5 and 1 M. Electrolytes directly affect the carboxylate groups of the rhamnolipids. The solution/air interface has a net negative charge due to the dissociated carboxylate ions at pH 6.8 with strong repulsive electrostatic forces between the rhamnolipid molecules. This negative charge is shielded by the Na⁺ ions in the electrical double layer in the presence of NaCl, causing the formation of a close-packed monolayer, and a decrease in CMC, and surface tension values. The maximum compaction is observed at 0.5 M NaCl concentrations for R1 and R2 monolayers, with the R1 monolayer more compact than R2. The larger spaces left below the hydrophobic tails of R1 with respect to that of R2, due to the missing second rhamnosyl groups are thought to be responsible for the higher compaction. The rigidity of both R1 and R2 monolayers increases with the electrolyte concentration. The rigidity of the R1 monolayer is greater than that of R2 at all NaCl concentrations due to the lower hydrophilic character of R1. The variation of CMC values as a function of NaCl concentration obtained from the surface tension measurements and critical packing parameter (CPP) calculations show that spherical micelles, bilayer and rod like micelles are formed in the rhamnolipid solutions as a function of the NaCl concentration. The results of optical microscopy supported these aggregation states indicating lamellar nematic liquid crystal, cubic lamellar and hexagonal liquid crystal phases in R1 and R2 solutions depending on the NaCl concentration.     

Effects of processing parameters on the mechanical properties of polypropylene random copolymer

The mechanical properties of polypropylene random copolymer (PP-R) with different processing parameters were studied. Special attention is devoted to the investigation of the influence of masterbatch addition on the variation in the mechanical properties of injection moulded PP-R. Tensile, instrumented Charpy impact, Shore D hardness, differential scanning calorimeter (DSC) and Vicat softening temperature (VST) tests were conducted on the test samples containing different colour masterbatches varying from 0.5 to 10 wt%. The observed changes in the mechanical behaviour are explained by the type and level of masterbatch content. The natural UV weathering performance of the PP-R material was studied from the masterbatch type point of view. The effect of processing parameters on material performance was studied on samples which were directly obtained from extruded pipes and on injection moulded samples.

Finally, the effects of storage time on the polymer properties were investigated.