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1.
含三氟甲基二苯醚类除草剂的合成   总被引:4,自引:0,他引:4  
张晓晨 《化学工程师》2004,18(11):54-56
本文讨论了含三氟甲基二苯醚类除草剂的合成方法,简要介绍了合成工艺,包括的品种有:三氟羧草醚、氟磺胺草醚、乙羧氟草醚、乳氟禾草灵,并提出了今后的改进方向。  相似文献   

2.
目前已商品化和开发研究的含氟二苯醚类除草剂有20多个,文中介绍了其品名、结构式、开发公司及应用范围,较详细地叙述了乙氧氟草醚、三氟羧草醚、氟磺胺草醚、克阔乐及乙羧氟草醚的制备方法。我国在“七五”期间已开发成功二硝基苯胺类除草剂氟  相似文献   

3.
3-[2-氯-4-(三氟甲基)苯氧基]苯甲酸是一种重要的中间体,由它可以合成三氟羧草醚等多种二苯醚类除草剂。本文概述了3-[2-氯-4-(三氟甲基)苯氧基]苯甲酸的合成改进方法。  相似文献   

4.
3-[2-氯-4-(三氟甲基)苯氧基]苯甲酸是一种重要的中间体,由它可以合成三氟羧草醚等多种二苯醚类除草剂。概述了3-[2-氯-4-(三氟甲基)苯氧基]苯甲酸的合成路线及改进方法。  相似文献   

5.
对硝基二苯醚类除草剂根据它们苯环(图1中的A环)上取代的位置可以分为两类:邻对位取代及间位取代的化合物。第一类化合物例如乙氧氟草醚[2-氯-1-(3-乙氧基-4-硝基苯氧基)-4-(三氟甲基)-苯]和三氟羧草醚[5-(2-氯-4-(三氟甲基)苯氧基)-2-硝基苯甲酸],通过使植物细胞迅速过氧化光导致漂白和干化而发挥除草作用。除草剂的首位靶标已知为原卟啉原氧化酶,这是亚铁原卟啉和叶绿素生物合成中最为普通的酶。除草剂作用机  相似文献   

6.
采用溶胶-凝胶法制备了铜掺杂改性二氧化钛光催化剂,考察了催化剂用量、光照时间、溶液pH值、铜离子浓度对三氟羧草醚光催化降解效率的影响并与非改性二氧化钛催化降解效率进行了对比。结果表明催化剂用量1.0 g/L、光照时间4 h、pH值4.58的最佳实验条件下,该催化剂处理三氟羧草醚废水的催化降解效率可达92%以上,比非改性二氧化钛催化降解效率提高30%以上,实验结果可为光催化处理难降解二苯醚类除草剂农药废水提供依据。  相似文献   

7.
业已证实,几种2-氯-4-(三氟甲基)-3'-取代-4'-硝基二苯醚除草剂,芽前或芽后施用对防除广范狭叶和阔叶杂草有优良的活性,而同时对作物亦具有很高的药害。唯已开发用作大豆田防除阔叶杂草芽后使用的选择性除草剂三氟羧草醚{acifluorfen-sodium,5-[2-氯-4-(三氟甲基)苯氧基]-2-硝基苯甲酸钠}是个例外(Johnson等,1978)。日本旭化学工业公司采用系统合成的方法,对许多3'位不同取代基的二苯醚类化合物  相似文献   

8.
二苯醚类除草剂乙氧氟草醚   总被引:3,自引:0,他引:3  
范莲生 《农药》2000,39(2):39-40
乙氧氟草醚 (oxyfluorfen)是二苯醚类除草剂 ,国外商品名为果尔。化学名称 :2 -氯 -1 -(3 -乙氧基 -4 -硝基苯氧基 ) -4 -(三氟甲基 )苯。化学结构 :F3CClOOC2 H5NO2乙氧氟草醚是美国罗姆 -哈斯公司开发的含氟二苯醚类除草剂。是一种高效、低毒、低残留、选择性、水旱田兼用、广谱苗前苗后触杀型除草剂。可广泛用于水稻、大豆、棉花、油菜、蔬菜、果树、森林苗圃及其它经济作物防除多种季节性阔叶杂草和禾本科杂草。1 理化性质乙氧氟草醚原药外观为淡黄色至红褐色固体 ,相对密度 1 .4 9(2 5℃ ) ,沸点 (2 50~ 3 0 0 …  相似文献   

9.
本发明公开了生产农用除草剂三氟羧草醚、氟磺胺草醚、乙羧氟草醚的中间体3-(2-氯-a,a,a-三氟对甲苯氧基),苯甲酸的合成方法,其主要采用3-(2-氯-a,a,a-三氟对甲苯氧基)-甲苯、乙酸酐、V2O5和MBr的组合物在反应容器中与空气接触并氧化,  相似文献   

10.
[目的]明确8种茎叶处理除草剂对花生田杂草的防除效果和对花生的安全性。[方法]采用田间小区试验方法进行药效试验。[结果]15%精喹禾灵·乙羧氟草醚EC、37%精喹禾灵·三氟羧草醚·灭草松ME和12%精喹禾灵·乙羧氟草醚·甲咪唑烟酸ME的剂量分别为135.00、832.50、180.00 g a.i./hm~2时,药后40 d对花生田一年生杂草防效均达到95%以上。[结论]精喹禾灵·乙羧氟草醚、精喹禾灵·三氟羧草醚·灭草松和精喹禾灵·乙羧氟草醚·甲咪唑烟酸可有效防除花生田杂草,并对花生有较好的安全性。  相似文献   

11.
Olfactory-mediated behavioral interactions were investigated among the five scolytid species comprising the southern pine bark beetle group. Behavioral response, as determined from field trap catch data, showed that each species was attracted in greatest numbers to the pheromonal blend produced by conspecifies. Interspecifically,D. frontalis displayed no cross-attractancy toIps pheromonal blends, but was weakly attracted to the pheromonal blend of femaleD. terebrans. ThreeIps species displayed varying degrees of cross-attraction as well as to theDendroctonus pheromonal blends. More specifically,I. calligraphus was attracted toI. avulsus and, to a very limited extent, also to the maleD. terebrans pheromonal blend.I. avulsus was somewhat more cross-attractive thanI. calligraphus and showed attraction to the pheromonal blends of femaleD. frontalis, male and femaleD. terebrans, maleI. calligraphus, and maleI. grandicollis. I. grandicollis showed the greatest degree of cross-attraction, particularly in response to theDendroctonus pheromonal blends.Research support in part by CSRS grant 86-CRCR-1-2270, NATO grant CRG.0710/86 and Texas Agricultural Experiment Station project MS1525 (while M.T.S. and T.L.P. were with Texas A&M University). The findings, opinions, and recommendations expressed herein are those of the authors and not necessarily those of the U.S. Department of Agriculture.  相似文献   

12.
The effect of aphid population size on host-plant chemical defense expression and the effect of plant defense on aphid population dynamics were investigated in a milkweed-specialist herbivore system. Density effects of the aposematic oleander aphid, Aphis nerii, on cardenolide expression were measured in two milkweed species, Asclepias curassavica and A. incarnata. These plants vary in constitutive chemical investment with high mean cardenolide concentration in A. curassavica and low to zero in A. incarnata. The second objective was to determine whether cardenolide expression in these two host plants impacts mean A. nerii colony biomass (mg) and density. Cardenolide concentration (microgram/g) of A. curassavica in both aphid-treated leaves and opposite, herbivore-free leaves decreased initially in comparison with aphid-free controls, and then increased significantly with A. nerii density. Thus, A. curassavica responds to aphid herbivory initially with density-dependent phytochemical reduction, followed by induction of cardenolides to concentrations above aphid-free controls. In addition, mean cardenolide concentration of aphid-treated leaves was significantly higher than that of opposite, herbivore-free leaves. Therefore, A. curassavica induction is strongest in herbivore-damage tissue. Conversely, A. incarnata exhibited no such chemical response to aphid herbivory. Furthermore, neither host plant responded chemically to herbivore feeding duration time (days) or to the interaction between herbivore initial density and feeding duration time. There were also no significant differences in mean colony biomass or population density of A. nerii reared on high cardenolide (A. curassavica) and low cardenolide (A. incarnata) hosts.  相似文献   

13.
Three species ofIps pine bark beetles in Hopping's group IX (S.L. Wood'sgrandicollis group),Ips confusus, I. lecontei, andI. paraconfusus, are parapatrically distributed in the American Southwest. They share post-Pleistocene altitudinal ecotones with their host pines. Adjacent to these areas of host overlap, we tested the hypothesis that aggregation pheromones produced by male beetles and/or host volatiles are sufficient to elicit the speciesspecific colonization behaviors typical of these threeIps species in nature. A more distantly related species,I. pini (Hopping's group IV, S.L. Wood'spini group) was used for outgroup comparison. Under the influence of pheromone, males ofI. confusus andI. paraconfusus do not discern among unin-fested log bolts of host and nonhost pine prior to bark contact. Males responding to pheromones emanating from infested bolts are similarly undiscriminating. Females ofI. confusus andI. lecontei olfactorily discern the combination of conspecific males in host pine from other possible beetlepine combinations; females ofI. paraconfusus do not. FemaleI. pini discerned conspecific pheromone from that ofI. lecontei. The bark beetle predator,Enoclerus lecontei, is attracted by, but does not discriminate among, the male-produced volatiles of these Group IXIps species. These results support a hypothesis that divergence in pheromonal responses by these group IXIps species has evolved following their speciation, having been manifested first in the female sex. Evolutionarily, the derived pheromonal messages have preceded their behavioral discrimination by these beetles. Additional speciesspecific cues may operate between the sexes in the field that may preclude heterospecific pairings.  相似文献   

14.
Females of severalAttagenus species demonstrated calling behaviors similar to those previously reported forA. elongatulus. Attagenus rufipennis females did not call until they were 12–14 days old. OtherAttagenus species called at approx. 4 days of age. All species exhibited diurnal periods of calling activity. Interspecific pheromone responses were tested, withA. megatoma megatoma, A. megatoma canadensis, A. megatoma japonicus, andA. schaefferi spurcus showing equal cross-responses. Male response to females was demonstrated inA. rufipennis andA. bicolor. Attagenus rufipennis, bicolor, andelongatulus males responded only to female extracts of their own species.Mention of a proprietary product does not constitute an endorsement by the USDA.  相似文献   

15.
Allelopathic interactions among algae   总被引:1,自引:0,他引:1  
Five species of green algae isolated from the Cleveland County, Oklahoma, area and a commercially obtained yellow-green alga were tested for allelopathic interactions. Axenic cultures ofPandorina morum Bory were stimulated in three sterile filtrates from nonaxenic cultures ofScenedesmus incrassatulus var.mononae G.M. Smith, with the oldest filtrate showing the least stimulation. By measuring the growth of axenic cultures inoculated into sterile filtrates of old cultures, instances of inhibition and stimulation were recorded in three screening experiments.Cosmarium vexatum West filtrate was inhibitory to the five other species, a characteristic probably important in its role of producing waterblooms in ponds and swamps. The allelopathic effects of filtrates of the five other species onBolrydium becherianum Vischer could be a key to its restriction to terrestrial sites. Instances of heat lability of the active substances were noted. These interactions, both allelopathic and stimulatory, probably play a significant role in the succession of algal blooms in nature.  相似文献   

16.
国外生物降解聚合物的种类及主要组分   总被引:3,自引:0,他引:3  
据1996~1998年国外有关文献的汇集,由美,日,德等国主要研制,生产的生物降解聚合物种类为:1,单一型生物降解聚合物;(1)合成酯(酸)类;(2)淀粉基材料;(3)天然高分子材料;2、复合型生物降解聚合物;(1)不同种类的烃基互聚物;(2)烃酯(酸)/聚酯(3)脂肪族聚酯/芳香族聚酯共聚物;(3)淀粉基复合型,(5)光/生物降解聚合物;3、可生物降解水溶性聚合物。  相似文献   

17.
The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 g of cardenolide per 0.1 g dry weight with a mean of 90 g per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 g of cardenolide per 0.1 g dry weight with a mean of 179 g. Total cardenolide per butterfly ranged from 54 to 1279 g with a mean of 319 g. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED50 units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications. About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.Lepidoptera: Danaidae.Apocynales: Asclepiadaceae.This study was supported by U.S. National Science Foundation grants DEB 75-14265 and 78-10658 to Amherst College and BSR-8119382 to the University of Florida with L.P. Brower as Principal Investigator and DEB75-14266, DEB78-15419, and DEB-81-19391 to the University of California at Davis with J.N. Seiber as Principal Investigator.  相似文献   

18.
The effects of glandular trichome/methyl ketone (2-tridecanone and 2-undecanone) -based insect resistance in the wild tomato,Lycopersicon hirsutum f.glabratum C.H. Mull, accession PI 134417, onArchytas marmoratus (Townsend) andEucelatoria bryani (Sabrosky) (Diptera: Tachinidae), both parasitoids ofHelicoverpa (=Heliothis)zea (Boddie) (Lepidoptera: Noctuidae), were investigated in the laboratory.A. marmoratus deposits larvae (planidia) on the foliage of its host's food plant; planidia attach to passing hosts, penetrate the cuticle, and develop in the host pupae.E. bryani larviposits directly into its host; its larvae develop in the host larva.A. marmoratus planidia are killed by glandular trichomes of PI 134417 and also by trichomes of hybrid lines with no methyl ketones. The methyl ketones are toxic to planidia, but at least part of the effect is due to other factors, possibly physical entanglement. Both species can be affected indirectly by methyl ketones in the diet of the host. 2-Undecanone reduces the percentage ofA. marmoratus larvae that reach pupation. This effect is evidently due to premature death and desiccation of the host pupa caused by 2-undecanone. 2-Tridecanone in host diets had no effect onA. marmoratus. InE. bryani, 2-tridecanone in the diet of the host reduced the number of parasitoids yielded by each parasitized host, although not the overall percentage of hosts parasitized. 2-Undecanone in the diet of the host had no effect onE. bryani.We thank M. Woodall for typing; V.B. Covington, D. Bumgarner, and B. O'Brien for technical assistance; L.A. Jones for assistance with gas chromatography; P.H. Adler for supplyingE. bryani puparia to initiate colony; and Drs. F. Gould, G.C. Rock, and M. Barbercheck for comments.  相似文献   

19.
DMC (Dynamic Matrix Control) has been used successfully in industry for the last decade. It can deal with constraints and unusual dynamic behavior directly. It also shows a good control performance for the servo problem. Relatively, it can’t reject disturbances systematically. We propose a modified DMC method to control the regulatory process more efficiently. The proposed DMC method makes the control output by subtracting the estimated disturbance from the control output of the original DMC. Here, the disturbance is estimated by a new disturbance estimator. It shows better control performances than the original DMC.  相似文献   

20.
The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.  相似文献   

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