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1.
Sex gland extracts and washes ofEupoecilia ambiguella contain 10–20 ng/female of the primary sex pheromone componentZ-9-dodecenyl acetate (Z9–12Ac), accompanied by a number of related compounds. These areE-9-dodecenyl acetate (E9–12Ac),Z-9-dodecen-1-ol (Z9–12OH), saturated acetates of 12, 16, 18, and 20 carbons, and traces of a doubly unsaturated acetate, tentatively identified as a 9,11-dodecadienyl acetate. Octadecyl acetate predominates among the pheromone-related components, making up 1–2, occasionally 20–30 times the amount ofZ9–12Ac. The same compounds were also found in field-collected females and in effluvia.Z-9-Undecenyl acetate, which is a male attractant on its own, was also found in a sample of female effluvia. A hierarchy is observed in the ethological function of the pheromone components.Z9–12Ac is an attractant forE. ambiguella males. Dodecyl acetate (12Ac) is not attractive on its own but augments male catch when added to the main attractant. Addition of 18Ac augments attraction only when bothZ9–12Ac and 12Ac are present. Windtunnel tests demonstrate that 18Ac also raises the disorientation threshold, as previously shown for 12Ac. Other compounds, with the possible exception of additional saturated acetates, had either no effect on trap catch or, in the case ofE9–12Ac,Z9–12OH, andE-9,11-dodecadienyl acetate, were inhibitory above a certain level. A blend of roughly equal parts ofZ9–12Ac, 12Ac, and 18Ac provides the best attractant blend forE. ambiguella known to date.  相似文献   

2.
Columnar, porous, magnetron-sputtered molybdenum and tungsten films show optinum performance as AMTEC electrodes at thicknesses less than 1.0 m when used with molybdenum or nickel current collector grids. Power densities of 0.40 W cm–2 for 0.5 m molybdenum films at 1200 K and 0.35 W cm–2 for 0.5 m tungsten films at 1180 K were obtained at electrode maturity after 40–90 h. Sheet resistances of magnetron sputter deposited films on sodium beta-alumina solid electrolyte (BASE) substrates were found to increase very steeply as thickness is decreased below about 0.3–0.4 m. The a.c. impedance data for these electrodes have been interpreted in terms of contributions from the bulk BASE and the porous electrode/BASE interface. Voltage profiles of operating electrodes show that the total electrode area, of electrodes with thickness <2.0 m, is not utilized efficiently unless a fairly fine (1×1mm) current collector grid is employed.  相似文献   

3.
The pheromone ofArgyrotaenia velutinana (Walker) is a 928150 mixture of (Z)-11-, (E)-11-tetradecenyl and dodecyl acetates. An 8515 blend of (Z)-11- and (E)-11-tridecenyl acetates produces a trap catch equivalent to that with the pheromone blend. The sensory input elicited by (Z)-11-tridecenyl acetate appears to substitute for the sensory input of both (Z)-11-tetradecenyl and dodecyl acetates, whereas the input from (E)-11-tridecenyl acetate appears to substitute for that of (E)-11-tetradecenyl acetate. Surprisingly, addition of dodecyl acetate to the tridecenyl acetates mixture decreases trap catches.Lepidoptera: Tortricidae.  相似文献   

4.
Twelve products related to the sex pheromone main components (Z)-9- and (Z)-11-tetradecenyl acetate (Z9–14Ac andZ11–14Ac, respectively), were identified in female pheromone gland extracts of the laboratory-reared summerfruit tortrix moth,Adoxophyes orana F.v R. These are the geometric isomers and the alcohols of the main components, (Z)-9-dodecenyl acetate, (Z)-11-hexadecenyl acetate, and saturated acetates of 12–22 carbons. The ratio ofZ9–14Ac toZ11–14Ac in individuals varied from 3.51 to 111 with an average of 6.2; their total added up to 462 ng/female with an average of 182 ng for 2- to 7-day-old individuals. No qualitative or quantitative differences were observed between laboratory and field insects.Z9–14Ac,Z11–14Ac and the corresponding alcohols were also found in female effluvia. Addition of either of the two alcohols to a blend of the two acetates augmented trap catch in the field. The same was true for (Z)-9,(E)-12-tetradecadienyl acetate which was not detected in gland extracts.  相似文献   

5.
Eleven pheromone-like compounds were identified in excised abdomen tip extracts of calling adult females of darksided cutworm,Euxoa messoria (Harris). The essential pheromone components were (Z)-7- and (Z)-11-hexadecenyl acetates in a ratio of 140, which agreed with an attractant blend developed empirically by field testing the attractancies of synthetic blends. The pheromone component, (Z)-11-hexadecenol, improved the attraction of darksided cutworm males whereas the components (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate inhibited their attraction. The other pheromone-like compounds identified in the female extracts had no obvious effect on the attraction of darksided cutworm males. Three compounds that functioned as parapheromones when substituted for (Z)-7-hexadecenyl acetate in the two-component blend were (Z)-7-pentadecenyl, (Z)-7-tetradecenyl, and (Z)-7-tridecenyl acetates. (Z)-11-hexadecenal was not detected in the female extracts, but it had a synergistic effect on the attraction of darksided cutworm moths and inhibited the attraction of male moths of a nontarget species,Helotropha reniformis (Grote). As a trap bait for monitoring purposes, we recommend a four-component blend of (Z)-7-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenol, and (Z)-11-hexadecenal at 12.5, 500, 1, and 10 g/red rubber septum dispenser containing 5 g of antioxidant 2,6-tert-butyl-4-methyl phenol. This blend is effective under field conditions for at least six weeks.  相似文献   

6.
Summary Molecular motions of elastomers under deformations were observed through dynamic mechanical measurements. Composite master curves of dynamic moduli E and E and loss tangent tan over a wide range of frequency and in a state of elongation were obtained by the time-temperature superposition procedure. It is found that both moduli increase with strain, . The slope of the dispersion curve of E become more gradual with the increase in , while that of E is almost unchanged. The increment of E is generally larger than that of E, which does not agree with the N. W. Tschoegl prediction, E * ()=f() E o * (), where E * () and E o * () are complex moduli at the strain of and O, respectively, and f() is the function of only . The difference in the strain dependence of E from E was found to correspond to the strain dependence of the equilibrium modulus.  相似文献   

7.
Six hydrocarbon components (2-methylhexadecane,n-heptadecane, 2-methylheptadecane, 2-methyloctadecane,n-nonadecane, and 2-methylnonadecane) were identified in sex-pheromone gland extracts and in airborne collections ofHolomelina lamae. Low variability in the ratio of components among individuals indicates tight regulation of blend composition. Minor changes were evident in the quantity and ratio of the blend as a function of time of day. Based on gland extracts, the total quantity of the six components increased from day 1 (X = 6299 ng) to day 4 (X = 7498 ng) and subsequently decreased. No significant correlations were found between total gland contents and wet or dry weights of moths. Emission rates ofH. lamae females were determined from pheromone adsorbed onto Porapak Q. Quantities released peaked shortly after the onset of calling and decreased rapidly as calling continued. Peak release rates ranged from 13 to 350 ng/10 min, and from 37 to 835 ng/60 min. Noncalling females did not emit detectable quantities of pheromone. Based on release rates and the rate of pulsation of the abdominal tip, the average amount released per pulse is not constant. The mean ratio of components released (0.787.45 84.802.842.591.53) was not very different from the ratio of components in gland extracts of 2-day-old females (0.704.1990.12 1.651.911.42). We propose that the blend is atomized rather than volatilized from the gland, thus retaining nearly the same ratios in the female's effluvium as in her gland.  相似文献   

8.
The effect of pulsating flow on the mass transfer in an annular electrodialysis cell has been studied in terms of the limiting current. The results indicate that the limiting current is influenced by the fluid velocity, the pulsation amplitude and the pulsation frequency, giving an increase of 400% with respect to the steady state. For a given amplitude, the dimensionless velocity, 0 (0 = a/v), can be taken as a representative parameter of the pulsation effect on the mass transfer. The fractional increase in the Sherwood number in pulsating flow with respect to the steady state has been correlated in terms of the dimensionless velocity, 0, and the Stokes number, 1 (1 = Deq (/)1/2), giving the correlation:  相似文献   

9.
The electrochemical behavior of non-alkyl substituted viologen, 4,4-dibenzyl bipyridinium (BzV), 4,4-dicyanophenyl bipyridinium (CyV) and -,-,-cyclodextrin (, , -CD) was studied using cyclic voltammetry and a spectroelectrochemical method. It was found that BzV and Fe(CN) 6 4– formed a charge-transfer (CT) complex with a ratio of 21 and the colour of the solution faded with the addition of an electrolyte. This behaviour is the same as in then-heptyl viologen and ferrocyanide system [1]. BzV, -CD and -CD formed an inclusion complex only in the reduced state, whilst BzV and -CD formed an inclusion complex in both the oxidized and the reduced state. An EC scheme in which a chemical reaction follows an electrochemical reaction was considered to predominate in the BzV and -, -CD systems, while a CE scheme in which a chemical reaction preceded an electrochemical reaction predominated in the BzV and -CD system. On the other hand, CyV was found to form an inclusion complex with -, -, -CD in both the oxidized and the reduced states. therefore a CE scheme was considered to predominate in the CyV--, -, -CD systems.  相似文献   

10.
The convective regime of filtration combustion of energetic materials in a cocurrent flow of their combustion products is studied using a model with extremely simplified kinetics and heat transfer, which shows instability of the process. It is shown that the more accurate twotemperature model describes a steadystate regime. In this regime, the gas temperature on the hot boundary of the heating zone is well below the combustion temperature, and the solidphase temperature is well below the temperature proposed in recent studies on this topic. It is pointed out that the twotemperature approach is unjustified and intragranular nonisothermicity must be taken into account for convective regimes. It is shown that the threetemperature model, which takes into account this effect, does not give a stable steadystate solution.  相似文献   

11.
Previously, (Z)-11-tetradecen-1-yl acetate was reported as the sex pheromone of the obliquebanded leafroller,Choristoneura rosaceana (Harris). A mixture of 92% (Z)-11-tetradecen-1-yl acetate and 8% (E)-tetradecen-1-yl acetate has been reported as an attractant for this insect. (E)-11-tetradecen-1-yl acetate and (Z)-11-tetradecen-1-ol have now been isolated and identified from female tip extracts and shown to be behaviorally active; in addition, there is some evidence for the presence of (E)-11-tetradecen-1-ol in these extracts. TheZE ratio for both the acetates and the alcohols in these tip extracts was about 982; the proportion of alcohols was rather variable, but the acetates always predominated. Maximum trap catches fn the field during the course of this study were obtained with 5 mg of 955 (Z)(E)-11-tetradecen-1-yl acetates containing 0.5–10% (Z)-11-tetradecen-1-ol (approx. 1%Eisomer) in polyethylene caps. No evidence was found for the presence of (Z)-11-tetradecenal in female tip extracts, and this compound was found to be ineffective in increasing trap catches.Lepidoptera: Tortricidae: Tortricinae.This research was supported in part by the Rockefeller Foundation, and by NSF Grant No. GB-38020.  相似文献   

12.
Coating and Characterization of Titania Membrane on Porous Ceramic Supports   总被引:2,自引:0,他引:2  
In this article, we reported experimental results on the development of microstructure of the membrane layer deposited on a porous support. The changes in porosity and mean pore diameter were followed as a function of layer thickness. It was found that in addition to particle packing and sintering within the membrane layer, the porous structure of support surface also exhibited certain effects on membrane microstructure until a critical thickness was reached. After that, the porous characteristics of a membrane would be totally determined by the packing and sintering characteristics of particles. It was also shown that the surface roughness could be reduced from about 1.5 m of the support, to 0.8 m after coating with 0.5 m titania particle and further reduced to about 0.55 m after another coating with 30 nm titania colloids. With proper dispersing and coating procedures, we could reduce the mean pore diameter from about 1.5 m of the support to 0.12 m, while the gas permeability was only changed from 500 × 10–7 to 250 × 10–7 mol/m2 s Pa.  相似文献   

13.
The sex pheromone components from the corn borer spreading widely in China,Ostrinia furnacalis Guenée, have been identified as (E)-and (Z)-12-tetradecenyl acetates (E andZ12–14 Ac). The ratio ofE isomer toZ isomer was 53 47. Traps containing 1 × 10–7–1 × 10–5 g of these compounds captured more males than did live females or their tip extract (3–6 female equivalents). Tetradecyl acetate (14 Ac) was also identified in the tip extract. Its quantity was about 1.8 times the sum of the other two isomers. However, including this compound in its natural ratio in pheromone traps resulted in a decrease in trap catches (P< 0.05).  相似文献   

14.
Electroantennogram (EAG) responses of maleRhopobota naevana (Hübner), the blackheaded fireworm, to all of the monoene straightchain 12- and 14-carbon alcohols and acetates implicated (Z)-11-tetradecenl-1-ol (Z11–14OH) and its acetate (Z11–14Ac) as sex pheromone components.Z11–14Ac produced the strongest EAG response of all compounds tested. Gas chromatography-mass spectrometry (GC-MS) analysis of extract of female sex pheromone glands (SPG) confirmed the presence ofZ11–14OH (125 pg/female) andZ11–14Ac (600 pg/female) (all other monoenes had different retention times). In field tests, traps baited withZ11–14OH alone captured males, but traps baited withZ11–14Ac alone did not. Traps baited with a combination ofZ11–14OH andZ11–14Ac in various ratios did not produce better trap catches thanZ11–14OH alone. (Z)-9-Dodecen-1-ol acetate (Z9–12Ac), reported by others to be a field attractant, did not produce trap catch in our tests, but in combination withZ11–14 OH (982 in septa corresponding to 95:5 in vapor,Z11–14OH toZ9–12AC) produced a sevenfold increase in catch overZ11–14OH alone. IfZ9–12AC had been present in extract of SPG at 2–5% ofZ11–14OH, it would not have been detected in our GC-MS experiment. Rhopobota naevana (Hübner) Lepidoptera: Tortricidae: Olethreutinae.  相似文献   

15.
Ab initio-calculated bond dissociation energies of Si=Si and C=C are discussed by means of atomic ionization energies and p-p() AO overlap. At the same time ring strain energies of C- as well as Si-rings are estimated by homodesmic reactions where, according to Baeyer, the two-membered rings C=C and Si=Si are chosen to be the first members of the respective series. Thus, a better understanding of the double bonds can be gained. In addition, the exceptional structural and spectroscopic behavior of the five-membered Si-ring is discussed. Finally, the strikingly different results obtained in computational studies of the initial step for polymerization of the systems O=C=O and O=Si=O are discussed.  相似文献   

16.
Response of lowland rice to sources and methods of nitrogen fertilizer application were summarized for more than 100 experiments. In about 2/3 of the experiments, the yield increase per kg of fertilizer N was judged to be relatively poor with best split applications of urea. Based on frequency distribution, sulfur coated urea and urea briquets or urea supergranules deep placed more often produced satisfactory yield increases than best split urea, but even with these sources/methods the yield increases were judged to be relatively poor in about 1/2 of the experiments. There is an enormous potential to increase rice production with no further increases in inputs of fertilizer N if we could learn to match the best method/source of fertilizer with the soil-crop management complex.About 60% of the yields with no fertilizer N were in the range of 2 to 4 t/ha. Based on the average yield response to urea, this is equivalent to about 100 kg of urea N. It would appear worthwhile to study ways to improve utilization of soil nitrogen since it is already in place on the land and apparently in fairly abundant amounts in many soils.About 50 experiments with15N fertilizers were summarized. In almost all cases, the uptake of tagged fertilizer was less than the net increase in N in the above ground matter. In about 2/3 of the experiments, the addition of fertilizer N increased soil N uptake more than 20% and in 1/3 of the experiments the uptake of soil N was increased more than 40%. These results lead to much uncertainty about practical interpretation and use of15N data.  相似文献   

17.
Conclusions If it is necessary to obtain a mineral powder with a high dispersion (mean 1 ), it is technically-undesirable and economically unsuitable to increase the quantity of grinding bodies by more than four times with respect to the weight of -Al2O3.Silicone oil is a suitable surface active agent for carrying out effective dry grinding of -Al2O3.With the dry grinding of -Al2O3 using metal grinding bodies, the iron pickup is approximately ten times greater than with wet grinding. During the dry grinding of -Al2O3 with an addition of silicone oil, and corundum grinding bodies, the rate of grinding is the same as with wet grinding using metal grinding bodies.Translated from Ogneupory, No. 8, pp. 71–72, August, 1971.  相似文献   

18.
Formulations of Mexican rice borer (MRB) pheromone components were more effective in capturing males in fields of sugarcane when dispensed from rubber septa than when evaporated from four other substrates. Concentrations of 0.63–10.0 mg of total pheromone per lure were effective over a 112-day period when formulated in rubber septa in a ratio of 811.3 of (Z)-13-octadecenyl acetate, (Z)-11-hexadecenyl acetate, and (Z)-13-octadecenal, respectively. Component ratios of 411.3 and 811.3 were equally effective in capturing male MRB, but efficacy decreased with higher relative concentrations of (Z)-13-octadecenyl acetate.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.  相似文献   

19.
H. He  H.X. Dai  K.Y. Ngan  C.T. Au 《Catalysis Letters》2001,71(3-4):147-153
The physico-chemical properties of passivated -Mo2N have been investigated. The material showed high activities for NO direct decomposition: nearly 100% NO conversion and 95% N2 selectivity were achieved at 450C. The amount of O2 taken up by -Mo2N increased with temperature rise and reached 3133.9 molg–1 at 450C; we conclude that there formation of Mo2OxNy occurred. This oxygen-saturated -Mo2N material was catalytically active: NO conversion and N2 selectivity were 89 and 92% at 450C. We found that by means of H2 reduction at 450C, Mo2OxNy could be reduced back to -Mo2N and the oxidation/reduction cycle is repeatable; such a behaviour and the high oxygen capacity (3133.9 molg–1) of -Mo2N suggest that -Mo2N is a promising catalytic material for automobile exhaust purification.  相似文献   

20.
When electroantennographic responses of maleYponomeuta malinellus Zeller to model compounds were determined at dosages of 0.3–30 ng, the strongest responses were obtained from (Z)-9-dodecen-1-ol acetate (Z9–12Ac). Also, strong responses were obtained from (Z)-11-tetradecenal (Z11–14A1) and (Z)-11-tetradecen-1-ol (Zl1–14OH). At a dosage of 0.3 ng,Z11–14A1 produced a stronger response thanZ11–14OH, while at a dosage of 30 ng,Z11–14OH andZ11–14A1 produced equal responses. Gas chromatographic and mass spectral analysis of extracts of female sex pheromone glands showed the presence ofZ9–12Ac, tetradecan-1-ol (14OH), (E)-11-tetradecen-1-ol (E11–14OH),Z11–14OH, hexadecan-1-ol, and hexadecan-1-ol acetate in a ratio of 0.62003710014035. In field tests,Z9–12Ac andZ11–14OH together were required for trap catch, and addition ofZ11–14A1,E11–14OH, 14OH, or (Z)-11-tetradecen-1-ol acetate did not increase catch. Ratios in rubber septa of 0.599.5 to 1.598.5 (Z9–12 Ac/Z11–14OH) captured the most males and captures were statistically equivalent for dosages of 10–1000 g/rubber septum. Traps baited with the synthetic lure produced better catches than those baited with females.Lepidoptera: Yponomeutidae.  相似文献   

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