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1.
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   

2.
Laboratory bioassays and field tests demonstrated that a Swiss population ofS. multistriatus responded much more strongly to - than to -miltistriatin in combination with 4-methyl-3-heptanol and -cubebene. High concentrations of brevicomin appeared to replace -multistriatin in evoking a response byScolytus species, but this effect can be explained by the fact that the brevicomin was contiminated with small amounts of -multistriatin. Frontalin, another bicyclic ketal, showed no biological activity. Field tests indicated thatS. pygmaeus aggregates to the same attractant mixture asS. multistriatus. S. scolytus also responded preferentially to this mixture, but the relative amounts of -multistriatin to 4-methyl-3-heptanol do not appear to be as important as forS. multistriatus.  相似文献   

3.
In situ13C and27Al MAS NMR and flow reactor studies were used to study the decomposition of dichloromethane and chloroform on zeolite ZnY. The initially formed products were framework-bound chloromethoxyl (from dichloromethane) and dichloromethoxyl (from chloroform) species, analogous to the non-halogenated alkoxyls observed in previous investigations. The principal components of the13C chemical shift tensors were: chloromethoxyl, 11 = 116 ppm, 22 = 79 ppm and 33 = 37 ppm; dichloromethoxyl, 11 = 128 ppm, 22 = 91 ppm and 33 = 65 ppm. Formation of both species occurred at 298 K, and each decomposed at 423 K. This decomposition formed HCl which dealuminated the zeolite (as monitored by27Al MAS NMR) causing deactivation (flow reactor studies). Further evidence for the destruction of the zeolite was the NMR observation of CO formation, implying incorporation of oxygen from zinc hydroxyl or framework sites. Although ZnY is shown to be unsuitable for catalytic chlorocarbon destruction, the observation of chloromethoxyl and dichloromethoxyl species is significant, and the formation of halogenated alkoxyl species should be considered in future investigations of halocarbon chemistry on oxides and molecular sieves.  相似文献   

4.
Summary Asymmetrically disubstituted poly(2-isopropoxy-5-methoxy-1,4-phenylene-vinylene), PIMPV, was prepared in thin films via organic-soluble precursor polymer method. These polymer films could be easily stretched up to 7 times, and the drawn films of the PIMPV could be doped with FeCl3 and I2 to give conductivities of 26.9 and 11.3 Scm-1, respectively. The third-order nonlinear optical susceptibility of the polymer was determined using third harmonic generation(THG) method at 1907 nm, fundamental wavelength. Measured (30) (-3: , , ) value was 3.7x10-12 esu.  相似文献   

5.
Four acetates,Z-5-decenyl acetate,Z-5-,Z-7-, andZ-9-dodecenyl acetates, in microgram ratios of 120021 or 120062 were excellent, specific sex pheromone blends for capturing male redbacked cutworm moths in cone traps. Blends in ratios of 120021 and 220021 at 1000 g/ rubber septum dispenser remained highly effective for 6 weeks under field conditions. The essential minor components,Z-5-decenyl,Z-7-, andZ-9-dodecenyl acetates, became inhibitory at concentrations of about 10% in the blends, and this may be an important general phenomenon in lepidopteran pheromones. Blends involving a parapheromone,Z-5-undecenyl acetate, withZ-5-,Z-7-, andZ-9-dodecenyl acetate, in microgram ratios of 820021 or 2020062 were also excellent specific attractants for this species. TheZ-8-dodecenyl acetate had no obvious effect on the attraction of the redbacked cutworm males.  相似文献   

6.
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   

7.
The cationic MnIII(Salen) complex was proved to be an effective catalyst for the oxidation of limonene with iodosobenzene as terminal oxidant. For reactions conducted in CH2Cl2 at rt, with molar ratio of 1 0.05 1 (limonene: catalyst: iodosobenzene) limonene oxidation does occur with an optimal conversion of 60%. The major products according to HRGC-MS and HRGC-IR analyses were cis- and trans-l,2-epoxylimonene (30% and 16.7%, selectivity, respectively), the two diastereoisomers of 1p-menthen-9-al (20% selectivity), and carvone (10% selectivity). A turnover of 60 was observed at 1 0.01 1 ratio. The higher selectivity toward epoxide formation supports the rebound oxygen mechanism.  相似文献   

8.
Mesoporous molecular sieve MCM-41 with a Si/Al ratio of 35 was obtained by hydrothermal synthesis using a gel mixture with a molar composition of 6 SiO20.1 Al2O31 hexadecyltrimethylammonium chloride 0.25 dodecyltrimethylammonium bromide 0.25 tetrapropylammonium bromide0.15 (NH4)2O1.5 Na2O300 H2O. The MCM-41 sample was calcined in O2 flow at 813 K and subsequently ion exchanged with Ca2+. A small Pt cluster has been supported on the MCM-41 sample following a procedure using ion exchange of Pt(NH3) 4 2+ . The Pt(NH3) 4 2+ ion supported on MCM-41 has been activated in O2 flow at 593 K and subsequently reduced with Fh flow at 573 K, in the same way used for the preparation of a Pt cluster entrapped inside the supercage of zeolite NaY. The resulting Pt cluster supported on the MCM-41 shows hydrogen chemisorption oftotal two H atoms per Pt at 296 K (based on the total amount of Pt) and high catalytic activity for hydrogenolysis of ethane. The chemical shift in129Xe NMR spectroscopy of adsorbed xenon indicates that the Pt cluster is located inside the mesoporous molecular sieve.  相似文献   

9.
Summary 3,5-Dimethoxy-4-(2-vinyloxyethoxy)-4-nitrostilbene 2 and 3,5-dimethoxy-4-(2-vinyloxyethoxy)-2,4-dinitrostilbene 5 were prepared by the reactions of 2-iodoethyl vinyl ether with 3,5-dimethoxy-4-hydroxy-4-dinitrostilbene 1 and 3,5-dimethoxy-4-hydroxy-2,4-dinitrostilbene 4, respectively. Monomers 2 and 5 were polymerized with cationic initiators to obtain polymers with the NLO-phores 3,5-dimethoxy-4-oxy-4-nitrostilbene and 3,5-dimethoxy-4-oxy-2,4-nitrostilbene in the side chain. The resulting polymer 3 and 6 were soluble in DMSO and DMF. The inherent viscosities of polymers were in the range of 0.28–0.33 dL/g in DMSO. Polymers 3 and 6 showed good thermal stabilities in their TGA thermograms, and the Tg values from DSC thermograms were in the range of 81–87°C.  相似文献   

10.
A bioassay was used to evaluate the effects of cuticular leaf components, isolated fromN. tabacum, N. glutinosa (accessions 24 and 24a), and 23other Nicotiana species, on germinationof P. tabacina (blue mold). The leaf surface compounds included- and-4,8,13,-duvatriene-l,3-diols (DVT-diols), (13-E)-labda-13-ene-8-,15-diol (labdenediol), (12-Z)-labda-12,14-diene-8-ol (cis-abienol), (13-R)-labda-8,14-diene-13-ol (manool), 2-hydroxymanool, a mixture of (13-R)-labda-14-ene-8,13-diol (sclareol), and (13-S)-labda-14-ene-8,13-diol (episclareol), and various glucose and/or sucrose ester isolates. The above in acetone were applied onto leaf disks of the blue moldsusceptibleN. tabacum cv. TI 1406, which was then inoculated with blue mold sporangia. Estimated IC50 values (inhibitory concentration) were 3.0g/cm2 for-DVT-diol, 2.9/cm2 for-DVT-diol, 0.4g/cm2 for labdenediol and 4.7g/cm2 for the sclareol mixture. Manool, 2-hydroxymanool, andcis-abienol at application rates up to 30g/cm2 had little or no effect on sporangium germination. Glucose and/or sucrose ester isolates from the cuticular leaf extracts of 23Nicotiana species and three different fractions fromN. bigelovii were also evaluated for antimicrobial activity at a concentration of 30g/cm2. Germination was inhibited by >20% when exposed to sugar esters isolated fromN. acuminata, N. benthamiana, N. attenuata, N. clevelandii, andN. miersii, and accessions 10 and 12 ofN. bigelovii. These results imply that a number of compounds may influence resistance to blue mold in tobacco.  相似文献   

11.
The bark beetleIps pini (Say) displays variation in its response to and production of enantiomeric blends of its pheromone ipsdienol. One of the principal predators ofIps pini isThanasimus dubius (F.), which uses ipsdienol as a kairomone for prey location. During 1988 and 1989, in Wisconsin and Michigan, the response of both species to a range of enantiomeric blends of ipsdienol was investigated. Blends tested had the following ratios of the (S)-(+) to (R)-(–) enantiomers: 3%97%, 25%75%, 50%50%, 75%25%, and 97%3%. Either75% (+) 25% (–) or 50% (+) 50% (–) ipsdienol captured the mostIps pini in both years at both sites. The 25% (+)75% (–) blend also caught moreIps pini than the control during both years at both sites. All blends tested were attractive toThanasimus dubius in both years at both locations. Blend preferences of both species were variable and labile at both sites. Response patterns of both species in Wisconsin were different from those in Michigan each year. Furthermore, response patterns of both species to the ipsdienol blends changed from 1988 to 1989 at both locations. A genetic component to this variation would permit predator-prey coevolution, as well as the development of resistance byIps pini to management strategies based on mass-trapping with single blends.  相似文献   

12.
The effect of the structure of AlF3 supports in CrF3/AlF3 catalysts and their activity were studied, and a selection of suitable reaction conditions for fluorination of trichloroethylene and HCFC-133a was made. We found that neither AlF3 (- and -modifications) nor CrF3/-AlF3 exhibits significant activity for the reaction of HF with CCl2=CHC1 or CF3CH2Cl. However, CrF3/-AlF3 exhibits high activity, which increases with increasing surface area and decreasing crystallite size of the -AlF3 support, and that dramatically affects the fiuorination of CF3CH2Cl. Investigation of a series of CrF3/-AlF3 catalysts shows that the turnover rates per unit of the total surface area and of the free CrF3 surface area significantly increase with increasing content of Cr3+ loading. Optimum temperature for the reaction of HF with CCl2=CHCl is 260°C, while with CF3CH2Cl it is 350°C, with flow ratios HFTCE = 61 andHFHCFC-133a = 101.  相似文献   

13.
A series of Al2O3-SnO2 catalysts with the mole ratio of Al2O3 to SnO2 equal to 1:1, 1 0.5, 1 0.1, 1 0.05 and 1 0.01 were characterized by31P NMR of adsorbed trimethyl phosphine (TMP) and119Sn MAS NMR spectroscopy. It was found from31P NMR that no Brønsted acid sites exist in these samples. Pure SnO2 shows two different types of Lewis acid sites; in the mixed oxide samples a Lewis peak characteristic of pure Al2O3 is always seen, together with either one or two other Lewis peaks, depending on the Sn concentration.119Sn CP/MAS NMR spectra of the highest Sn-content sample show one narrow line at –603 ppm superimposed on a very broad line, indicating a strong interaction between Al and Sn oxides.  相似文献   

14.
Thermal transition of PVA-borax aqueous gels with a PVA concentration of 60 g/L and a borax concentration of 0.28 M was investigated at temperatures ranging from 15 to 60C using static light scattering (SLS), dynamic light scattering (DLS), and dynamic viscoelasticity measurements. Three relaxation modes, i.e. two fast and one slow relaxation modes, were observed from DLS measurements. Two fast relaxation modes located around 10–3101 sec, with one fast mode (f1) being scattering vector q-dependent and the other fast mode (f2, with f2>f1) being q-independent. The f1 mode was attributed to the gel mode whilst the f2 mode could be due to the hydrodynamics of intra-molecular hydrophobic domains formed by uncharged segments of polymer backbones. The slow relaxation mode with relaxation time located around 101103 sec in DLS data was due to the motion of aggregated clusters and was observed only at temperatures above 40C. The amplitude and relaxation time of slow mode decrease as temperature is increased from 40 to 60C. At temperatures below 40C, no slow relaxation mode was observed. The SLS measurements showed PVA-borax-water system had fractal dimensions D f2.4 and D f2.0 as temperature was below and above 40C, respectively. The simple tilting test indicated gel behaviour for the PVA-borax aqueous system at temperatures below 40C with a creep flow after a long time exposure in the gravity field. But the dynamic viscoelasticity measurements demonstrated a solution behaviour for PVA/borax/water at temperatures below 40C, the critical gel point behaviour for G() and G() was not observed in this system as those reported for chemical crosslinked gels. These results suggest that the PVA-borax aqueous system is a thermoreversible weak gel.  相似文献   

15.
Summary Critical solution point and chain dimension were measured for branched polystyrene(BPS) in solution as a function of molecular weight(M) and compared with those for linear polystyrene(LPS). The critical concentration c of BPS was quite different from that of LPS at a fixed M, but the same at a fixed overlap-concentration *, i.e., plots of c vs. * fall on a single straight line for both BPS and LPS (gfc *). Reduced critical temperature c defined by gtc=(–Tc)/ [Tc: critical temperature, : the -temperature] was related to c as c c 2 for BPS, whereas c c for LPS.  相似文献   

16.
This paper presents a mathematical model to calculate the distributions of currenti(x), potentialE(x), gas void fraction (x) and pore electrolyte resistivity (x) within porous flow-through electrodes producing hydrogen. It takes into consideration the following effects: (i) the kinetics of the interfacial charge transfer step, (ii) the effect of the non-uniformly generated gas bubbles on the resistivity of the gas-electrolyte dispersion within the pores of the electrode (x) and (iii) the convective transport of the electrolyte through the pores. These effects appear in the form of three dimensional groups i.e.K=i o L where io is the exchange current density, is the specific surface area of the electrode andL its thickness.= 0 L where 0 is the pore electrolyte resistivity and =/Q where is a constant, =tortuosity/porosity of the porous electrode andQ is the superficial electrolyte volume flow rate within it. Two more dimensionless groups appear: i.e. the parameter of the ohmic effect =K/b and the kinetic-transport parameterI=K. The model equations were solved fori(x),E(x), (x) and (x) for various values of the above groups.Nomenclature specific surface area of the bed, area per unit volume (cm–1) - b RT/F in volts, whereR is the gas constant,T is the absolute temperature (K) - B =[1–(I 2 Z/4)], Equation 9a - C =(1–B 2), Equation 9b - E(L) potential at the exit face (V) - E(0) potential at the entry face (V) - E(x) potential at distancex within the electrode (V) - E rev reversible potential of the electrochemical reaction (V) - F Faraday's constant, 96500 C eq–1 - i o exchange current density of the electrode reaction (A cm–2 of true surface area) - i(L) current density at the exit face (A cm–2 of geometrical cross-sectional area of the packed bed) - I K =i oL(/Q) (dimensionless group), Equation 7d - K =i oL, effective exchange current density of the packed bed (A cm–2) Equation 7a - L bed thickness (cm) - q tortuosity factor (dimensionless) - Q superficial electrolyte volume flow rate (cm3 s–1) - x =position in the electrode (cm) - Z =exp [(0)], Equation 7f - transfer coefficient, =0.5 - =K/b=(i 0 L 0 L)/b (dimensionless group) Equation 7e - (x) gas void fraction atx (dimensionless) - = 0 L, effective resistivity of the bubble-free pore electrolyte for the entire thickness of the electrode ( cm2) - (0) polarization at the entry face (V) - (L) polarization at the exit face (V) - =q/, labyrinth factor - constant (cm3 C–1), Equation 3a - =/Q (A –1) conversion factor, Equation 3b - porosity of the bed - (x) effective resistivity of the gas-electrolyte dispersion within the pores ( cm) - 0 effective resistivity of the bubble-free pore electrolyte ( cm)  相似文献   

17.
Two sex pheromone components, 3(Z),6(Z),9(Z)-nonadecatriene (3Z,6Z,9Z-19 H), and 3(Z),6(Z),9(Z)-eicosatriene (3Z,6Z,9Z-20 H), have been positively identified, and a third component, 6(Z),9(Z)-nonadecadiene (6(Z),9(Z)-19 H) has been tentatively identified from abdominal tip extracts of female spring cankerworm moths,Paleacrita vernata Peck (Lepidoptera Geometridae). The pheromone components were identified by a combination of gas chromatography, electroantennography, mass spectrometry, chemical tests, comparison with standards, and field testing. Only 3Z,6Z,9Z-20 H exhibited significant attractant activity when tested alone, and it was potentiated by the other two components. The attractive blend was an 821 ratio of 3Z,6Z,9Z-20H/3Z,6Z,9Z-19H/6Z,9Z-19H. However, the two-component blend of 3Z,6Z,9Z-20 H and 6Z,9Z-19 H (81 ratio) was as attractive as the three-component blend in further field tests. A series of related compounds, the diene monoepoxides available from epoxidation of C19 and C20 3Z,6Z,9Z-trienes, some of which have been found in the pheromone blends of other moth species, were tested as behavioral antagonists. The attraction of male moths to synthetic lures was suppressed by the addition of 6Z,9Z-cis-3,4-epoxy-nonadecadiene to the lures. Additional experiments were performed to determine the effects of lure dosage, trap height, and trap design on the numbers of male moths captured.Issued as NRCC 30711.  相似文献   

18.
The lamellar morphology of a melt-miscible blend consisting of two crystalline constituents, poly(3-hydroxybutyrate) (PHB) and poly(ethylene oxide) (PEO) have been investigated by means of small angle X-ray scattering (SAXS). The blend was a crystalline/amorphous system when temperatures lay between the melting point of PEO (ca. T m PEO=60C) and that of PHB (ca. T m PHB=170C), while it became a crystalline/crystalline system below T m PEO. The crystalline microstructures of the blends were induced by two types of crystallization history, i.e. one-step and two-step crystallizations. In the one-step crystallization, the blends were directly quenched from the melt to room temperature to allow simultaneous PHB and PEO crystallization. The two-step crystallization involved first cooling to 70C to allow PHB crystallization for 72 h followed by cooling to room temperature (ca. 19C) to allow PEO crystallization. In the crystalline/crystalline state, two scattering peaks have been observed in the Lorentz-corrected SAXS profiles, irrespective of the crystallization histories, meaning that crystallization created separate PHB and PEO lamellar stack domains. One-step crystallization yielded lamellar stack domains containing almost pure PHB and PEO lamellae. Two-step crystallization generated almost pure PHB lamellar domains and the PEO lamellar domains with inserted PHB lamellae. In the crystalline/amorphous state, the composition dependence of the amorphous layer thickness (l a), the presence of zero-angle scattering, and the volume fraction of the PHB lamellar stack (s) revealed that both one-step and two-step crystallizations, generated the interfibrillar segregation morphology, where the extent of interfibrillar segregation of amorphous PEO increased with increasing PEO content.  相似文献   

19.
Isopropylation of biphenyl (BP) over [Al]-SSZ-31, a large-pore, one-dimensional zeolite has been studied. Effects of temperature, pressure and SiO2/Al2O3 ratio were examined. SSZ-31 was found to be an active catalyst in the isopropylation of biphenyl with propylene. The selectivity for 4-isopropylbiphenyl (4-IPBP) and 4,4-diisopropylbiphenyl (4,4-DIPB) was high among isopropylbiphenyl (IPBP) and diisopropylbiphenyl (DIPB) isomers, respectively, indicating SSZ-31 shows shape-selective catalysis. The selectivity for 4,4-DIPB decreased with temperature increase; correspondingly the selectivity for thermodynamically more stable isomers (3,3- and 3,4 DIPB) increased with temperature. The yield of IPBP isomers decreased while that of DIPB isomers increased with temperature increase. Pressure showed less effect on conversion; however, increase in pressure suppresses the isomerization of 4,4-DIPB to 3,3- and 3,4-DIPB. Conversion decreased with increase in SiO2/Al2O3 ratio. At low SiO2/Al2O3 ratio of 136, relatively high triisopropylbiphenyl (TriIPB) isomers were formed in bulk products and their amount decreased with increase in SiO2/Al2O3 ratio.  相似文献   

20.
Anisotropic oxidation of crystallites of vanadyl pyrophosphate ((VO)2P2O7) has been demonstrated by Raman spectroscopy with samples having different microstructures. Oxidation of these samples by O2 produced X1 phase,- and-VOPO4 phases. The relative peak intensity of the X1 phase to the other phases correlated well with the ratio of the (100) plane to the side planes (surface area-basis). This correlation showed that the (100) plane was oxidized to X1 phase and the side planes to- and-VOPO4. For example, thin plate-like (VO)2P2O7, of which the (100) fraction is 98%, was oxidized almost exclusively to X1 phase. But when it was fractured into small plates to increase the side planes and then oxidized,- and-VOPO4 were detected in addition to the X1 phase. These results are consistent with our previous conclusion that the (100) plane of (VO)2P2O7 is selective, but side planes are non-selective for catalytic oxidation ofn-butane.  相似文献   

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