Property changes of wood-fiber/HDPE composites colored by iron oxide pigments after accelerated UV weathering

Four kinds of iron oxide pigments were added into wood-fiber/high-density-polyethylene composites （WF/HDPE） at three different concentrations, to determine the effects of pigments on the changes in the color and mechanical properties of the composites before and after UV accelerated weathering. HDPE, wood fibers, pigments and other processing additives were dry-mixed in a high-speed mixer. The mixtures were extruded by two-step extrusion process with a self-designed twin-screw/single-screw extruder system. Color of the samples was determined according to CIE 1976 L^＊a^＊b^＊ system by a spec- trophotometer and the bending properties were tested to evaluate the mechanical properties before and after accelerated UV weathering. The result shows that the modulus of elasticity of WF/HDPE did not obvi- ously changed after incorporating with the pigments, but the bending strength increased. After accelerated aging for 2000 h, both color and mechanical properties significantly changed. Iron oxide red and black performed better than the other two pigments, and the pigments dosage of 2.28% in the composites is favourable.

犹太商人何以厉害

犹太商人是世界公认的第一商人.从罗斯柴尔德到索罗斯,从洛克菲勒到彼德森,众多犹太商业巨子的功名事业令世人翘首瞩目(犹太人在文化、科学、艺术等诸多方面一样盛产巨匠,这里不论).

Kinetic Study of Color Changes of Tomato Purees with Microwave and Conventional Drying

Kinetics of color change in tomato purees dried using microwave and conventional method were investigated. For this purpose, the color parameters of Hunter L,a,b and browning index （A42o）, and estimated values of chroma, hue angle, AE, Hunter a/b and a ~ b were examined. The changes in color of tomato samples followed both zero and first order kinetic models to describe visual color changes, and ＆E parameters followed first order kinetic. It was concluded that Hunter axb parameters can be used adequately to follow up the color change of tomato samples during the drying.

Fuzzy Mathematics for Raw Silk Size Control

With photographing and experiments, this paper divides the cocoon layers into three categories according to their colors, establishes three-color membership function based on fuzzy mathematics, constructs fuzzy sets which satisfy the range of size control by using the ordinary set and attached frequency of threecolor cocoons combination, then achieves the ordinary sets of range of size control by choosing λ-cut. Under these ordinary sets, each end does duality relative level, then sets up relative matrix and overall sequence and finds the membership function to judge whether the size control is mormal.

Effect of Colored Sticky Cards on Non-target Insects

Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yellow, blue, green, and red sticky cards were used to trap insects in the field. The total number of insects species caught was 54, with 3,862 individuals recorded. Over half of the specimens caught were non-target insects, including phytophagous insects, particularly dipteran species(including many mosquitoes)(50.3%), followed by target pests(37.0%), and beneficial insects(12.7%). Statistical analysis revealed a significant difference in attraction to target pests, non-target pests, and beneficial insects among treatment groups. The results showed that higher numbers of target pests(Myzus persicae Sulzer, Empoasca flavescens Fabricius, Nysius ericaecshinly Schilling) were caught on yellow sticky card traps compared with blue, green, or red sticky card traps, indicating that yellow was the best trap color for target pests, with green and blue being progressively less attractive. For non-target insects, including phytophagous insects, flies, and mosquitoes,higher numbers of were caught on blue sticky card traps compared with yellow,green, or red sticky card traps. Our study indicated that blue was the most attractive color for flies, especially for the housefly, Musca domestica Linnaeus. Our study also showed that most beneficial insects exhibited preferences to particular trap color characteristics: yellow was the most attractive color for parasitic wasps and lady beetles; blue was the most attractive color for hoverflies and honeybees. In contrast,green and red had no significant attraction to beneficial insects.

Color and behavior differently predict competitive outcomes for divergent stickleback color morphs

Our knowledge of how male competition contributes to speciation is dominated by investigations of competition between within-species morphs or closely related species that differ in conspicuous traits expressed during the breeding season （e.g. color, song）. In such studies, it is important to consider the manner in which putatively sexually selected traits influence the outcome of competitive interactions within and between types because these traits can communicate information about competitor quality and may not be utilized by homotypic and heterotypic receivers in the same way. We studied the roles of breeding color and aggressive behaviors in competition within and between two divergent threes- pine stickleback Gasterosteus aculeatus color types. Our previous work in this system showed that the switch from red to black breeding coloration is associated with changes in male competition biases. Here, we find that red and black males also use different currencies in competition. Winners of both color types performed more aggressive behaviors than losers, regardless of whether the competitor was of the same or opposite color type. But breeding color differently predicted competitive outcomes for red and black males. Males who were redder at the start of competition were more likely to win when paired with homotypic competitors and less likely to win when paired with heterotypic competitors. In contrast, black color, though expressed in the breeding season and condition dependent, was unrelated to competitive outcomes. Placing questions about the role of male competition in speciation in a sexual signal evolution framework may provide insight into the ＂why and how＂ of aggression biases and asymmetries in competitive ability between closely related morphs and species.

The dynamics of color signals in male threespine sticklebacks Gasterosteus aculeatus

Body coloration and color patterns are ubiquitous throughout the animal kingdom and vary be- tween and within species. Recent studies have dealt with individual dynamics of various aspects of coloration, as it is in many cases a flexible trait and changes in color expression may be context-de- pendent. During the reproductive phase, temporal changes of coloration in the visible spectral range （400-700 nm） have been shown for many animals but corresponding changes in the ultravio- let （UV） waveband （300-400 nm） have rarely been studied. Threespine stickleback Gasterosteus aculeatus males develop conspicuous orange-red breeding coloration combined with UV reflect- ance in the cheek region. We investigated dynamics of color patterns including UV throughout a male breeding cycle, as well as short-term changes in coloration in response to a computer- animated rival using reflectance spectrophotometry and visual modeling, to estimate how colors would be perceived by conspecifics. We found the orange-red component of coloration to vary during the breeding cycle with respect to hue （theta/R50） and intensity （achieved chroma/red chroma）. Furthermore, color intensity in the orange-red spectral part （achieved chroma） tended to be increased after the presentation of an artificial rival. Dynamic changes in specific measures of hue and intensity in the UV waveband were not found. In general, the orange-red component of the signal seems to be dynamic with respect to color intensity and hue. This accounts in particular for color changes during the breeding cycle, presumably to signal reproductive status, and with limitations as well in the intrasexual context, most likely to signal dominance or inferiority.