| 1. |
- Du, Jia Wei, et al.
(författare)
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Repeatability of pheromone emissions from individual female ermine moths Yponomeuta padellus and Yponomeuta rorellus
- 1987
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 13:6, s. 1431-1441
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Tidskriftsartikel (refereegranskat)abstract
- The repeatability of the composition of pheromone emitted by individual female moths (Yponomeuta) was determined by gas Chromatographic analysis. An improved technique for repeated collections of airborne volatiles from the same moth was developed. The procedure did not harm the females and allowed precise quantification of 0.05 ng of pheromone components in 30-min collections. Individual females of Y. padellus (N=10) and Y. rorellus (N=5) were sampled six and eight days after emergence. Y. padellus released, on average, 4.8 ng/30 min of tetradecyl acetate, (E)-11-tetradecenyl acetate, (Z)-11-tetradecenyl acetate, hexadecyl acetate, (Z)-9-hexadecenyl acetate, and (Z)-11-hexadecenyl acetate in the average ratio 445:38:100:494:35:421. The amount of (E)-11-tetradecenyl acetate relative to (Z)-11-tetradecenyl acetate was less variable [coefficient of variation (CV)=15%] than the relative amounts of the other components (CV=46-61%). The repeatability of the relative amounts of compounds released by individual females was high for all components (r=0.82-0.90). The average emission of tetradecyl acetate, tetradecanol, hexadecyl acetate, and hexadecanol by Y. rorellus was 8.3 ng/30 min (ratio 100:8:10:2). The repeatability was low for tetradecanol (r=0.51) but higher for hexadecyl acetate (r=0.87) and hexadecanol (r=0.89). The low interindividual variance for the (E)-11-/(Z)-11-tetradecenyl acetate ratio in Y. padellus might be due to its importance for reproductive isolation, i.e., it is under strong selection pressure.
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| 2. |
- Gao, Ming-Wei, et al.
(författare)
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Effect of powder filling on selection and breakage functions in batch grinding
- 1989
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Ingår i: Powder Technology. - : Elsevier BV. - 0032-5910 .- 1873-328X. ; 59:4, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- The effect of powder filling on selection and breakage functions is investigated. At three levels of powder filling, the selection functions are determined by one-size-fraction tests. The selection function decreases rapidly with increasing powder filling. When the powder filling is very low, the breakage function appears to be higher. Because of the non-normalization of the breakage function in this work a back-calculation method for determination of the breakage function is applied. For the non-normalized breakage function, if the selection function is known, it is possible to back-calculate a normalizable breakage function which gives the best simulation results. The effect of powder filling on product size distribution can be compensated by adjusting the grinding time. The material used was iron ore.
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| 3. |
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| 4. |
- Löfstedt, Christer, et al.
(författare)
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Evolution of the ermine moth pheromone tetradecyl acetate
- 1986
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 323:6089, s. 621-623
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Tidskriftsartikel (refereegranskat)abstract
- The nine sympatric forms of small ermine moths of the genus Yponomeuta (Lepidoptere; Yponomeutidae) in the west palaearctic region show various degrees of differentiation1,2, including among other characteristics, differences in their sexual pheromones3. As is the case for many other moths4, the ermine moths so far analysed use delta 11-unsaturated acetates ((Z)-11-tetradecenyl, (E)-11-tetradecenyl and (Z)-11-hexadecenyl acetate) as primary pheromone components. Here for the first time in Lepidoptera we report that a saturated acetate, tetradecyl acetate, is the primary pheromone component5 of Y. rorellus (Hübner). Y. rorellus is almost monomorphic with respect to isoenzyme variation6 and has fewer chromosomes than its relatives7,8. We suggest that it has evolved through loss of unsaturated pheromone components in a 'genetic revolution' at a population bottleneck, and by the founders of the new species filling an empty communication niche, separated from that of the ancestral species.
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| 5. |
- Zhang, Wei-Bin
(författare)
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Theory of economic development : nonlinearity, instability and non-equilibrium
- 1989
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of this study is to propose an economic development theory within the framework of input-output systems and neoclassical economics. This study consists of nine chapters which are arranged in the following manner:In Chapter I, we discuss development problems, define some essential concepts, and provide a general historical sketch of economic growth theory. Chapter II revises some of the modern mathematical economic growth theories. This chapter is mainly concerned with quantitative approaches. Chapter III reviews how monetary variables can be introduced into neoclassical growth theory. Prices in the context of dynamic multiple sector models are dealt with in Chapter IV. We mainly confine ourselves to those interactions which occur amongst interest rate, growth rate and inflation rate within the framework of multiple sector models. Chapter V is concerned with a "mixed" economy with a combination of centralization and decentralization. The central government’s behavior is assumed to maximize a social welfare function which depends on the economic growth rate. Chapter VI deals with the problem of the "choice of (exogenously given) alternatives or techniques". In Chapter VII we examine the process of endogenous technological changes. Dynamic interactions between human knowledge and economic variables are investigated within the framework of neoclassical theory. Chapter VIII explicitly introduces a new sector - called theknowledge or non-material sector - into the traditional input-output economic system. We attempt to develop models based upon the human capital theories of economics. Chapter IX summarizes the results of this study and suggests some mechanisms - the neoclassical, neo-Marxian and neo-Keynesian approaches - for "closing" an incomplete economic system which primarily consists of accounting equations.
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