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The compound eye is the main visual organ of insects and has the function of sensing size, shape and color. Research on the compound eye's structure is the basis for understanding insect vision and the role of the visual cues in insect behavior. Compound eyes are usually categorized into two major types; apposition, and superposition, eyes. Superposition eyes perform well in low intensity light but have low resolution, whereas apposition eyes do not perform as well in low intensity light but have higher resolution. Most diurnal insects have apposition eyes whereas superposition eyes are mainly found in nocturnal species. Molecular biology, electroantennogram experiments and behavioral analyses reveal that insects are most sensitive to ultraviolet, blue and green light. Insects use celestial cues and ground targets for orientation and navigation, including the polarization of light from celestial bodies and the contrast between landmarks and background color. Different kinds of cues may be used simultaneously. Vision plays a crucial role in the process of finding hosts, mates and oviposition sites, and should not be underestimated in entomological research. Knowledge of phototaxis can provide a theoretical basis for the environmentally-friendly control of pests, such as developing species-specific traps. [ABSTRACT FROM AUTHOR]

In order to optimize the hemp degumming process to reduce the dosage of alkali and the environmental pollution, the paper researches plasma acid-alkali degumming process. Plasma acid pretreatment conditions are worked out by single factor experiments, reaching the better conditions for degumming bath ratio is 1:20, the temperature is 60 °C, the time is 1 h. In this condition, the low alkali concentration is tested for secondary treatment process, which are, the alkali concentration is 8%, the bath ratio is 1:10, the temperature is 90, the time is 1 h. After the treatment, the content of hemp cellulose is 78.63%, pectin, hemicellulose, lignin decrease by 87.3%, 40.7% and 64.5% respectively, and has better removal effect of pectin, fiber soft, enhancing the performance of hemp fiber. [ABSTRACT FROM AUTHOR]

The key point of developing the wool - like hemp fiber is to make the quality index of fiber fineness, main body length and fracture strength more similar to wool fiber. The key technology of industrial wool-like hemp fiber production was realized by choosing the better hemp bast fiber, optimizing the process and degumming method as well as the optimization of multistep carding process and production process. And by this way, the chemical composition of hemp fiber declined gradually, the fiber thickness diminished steadily to thinner and the length gradual decreased to shorter. The wool-like hemp fiber was finally produced in 81. 5 mm and 4. 6 dtex. The 14. 5 tex wooVhemp ( 60/40) blended yarn was spinned out, the wool and hemp series blended fabrics were developed and had already been industrially produced. [ABSTRACT FROM AUTHOR]

Hemp yarn for knitting machine production in the existence of difficult woven into rings issues, in this paper it discussed hemp yarns were pretreatment with cellulose and enzyme and then with cationic softener to reduce the stiffness of hemp yarn. We got the best technological conditions through the orthogonal experiments. The result indicated that the best technological conditions were: cellulose enzyme 2% (owf), pH value 4. 5, temperature 50 °C, treating time 50 min, liquor ratio 1:15, then treated with softening agent under the condition of cationic softener 2. 5 g/L, temperature 50 °C and time 40 min. Through the finishing, the initial modulus of hemp yarn was reduced by 62. 82% . The treatment was an effective means in reducing hemp yarn stiffness and improving its knitting performance. [ABSTRACT FROM AUTHOR]

In the production of hemp fiber, degumming technology directly affect the spinning of hemp fiber. In the condition of 100?, the paper uses orthogonal test to study that alkali concentration and reaction time affect the content of pectin. Through studying the experimental results of orthogonal polynomial regression analysis, it establishs the regression equation among the content of hemp fiber pectin, alkali concentration and reaction time. Through the regression equation, it can obtain average error between account figure and experiment figure, which is ± 0.9665%. In the condition of 100?,it could make use of regression equation in order to optimize degumming technology conditions and forecast the content of pectin. It is important to improve the spinning performance of hemp fiber. [ABSTRACT FROM AUTHOR]