氟环唑与三环唑复配对水稻纹枯病和稻曲病的联合生物活性及田间防效

[目的]筛选能同时防治水稻纹枯病和稻曲病的高效药剂。[方法]采用菌丝生长抑制法、菌体指标测定和田间药效试验,评价氟环唑与三环唑混配组合的联合生物活性及对水稻纹枯病和稻曲病的田间防效。[结果]氟环唑与三环唑质量比1∶3复配,对水稻纹枯病菌和稻曲病菌的联合作用为增效作用,EC50值分别为2.1911、0.2374 mg/L,联合作用系数CTC分别为120.32、121.20;纹枯病菌初生分枝菌丝长度17.4～21.3μm,分枝菌丝间隙117.8～128.7μm,菌丝畸变明显;培养5.5 d后稻曲病菌孢子数2.6×10~5～3.5×10~5。田间防效表明:60%氟环唑·三环唑可湿性粉剂(质量比1∶3)288～360 g a.i./hm2防治水稻纹枯病,对"川绿优188"防效80.5%～87.6%,对"绿优4923"防效69.5%～85.3%;防治水稻稻曲病,对"川绿优188"防效76.2%～83.6%,对"绿优4923"防效62.6%～79.5%;显著高于单剂和对照药剂。[结论]氟环唑与三环唑质量比1∶3复配,用量288～360 g a.i./hm2,能兼治水稻纹枯病和稻曲病,达到农药减量增效的目的。     

25%苯醚甲环唑EC对水稻纹枯病和稻曲病的防治试验

田间采用25%苯醚甲环唑EC4个浓度药液防治水稻纹枯病和稻曲病,最高防效分别为88.94%和84.17%,比对照25%丙环唑EC的最高防效高出7.16%和10.79%,建议在水稻大田生产上大力推广使用。亩用量50mL左右。     

几种杀菌剂对水稻稻曲病的防治研究

水稻稻曲病是水稻生产上一种重要的真菌病害,近年发生严重。本试验选用30%爱苗EC(有效成分组成为:15%丙环唑+15%苯醚甲环唑)等7种不同杀菌剂在不同时期对水稻稻曲病进行了防治试验,以期为指导水稻生产上防治水稻稻曲病,正确选用药剂提供科学依据。结果表明,在破口前5～7d的施药防效普遍高于在始穗期的防效,其中30%爱苗EC15mL/667m2处理和20%井冈霉素SP6.5g/667m2处理的防治效果较好,均达到70%左右,而50%多菌灵WP62.5g/667m2处理的防效在所有处理中防效最低,仅在30%左右,且差异显著。     

25%腈菌唑乳油对水稻纹枯病和稻曲病的防治效果

[目的]探究25%腈菌唑乳油对水稻纹枯病和稻曲病的防治效果。[方法]采用叶面喷雾法试验25%腈菌唑乳油对水稻纹枯病和稻曲病的田间防效。[结果]25%腈菌唑乳油54~72 g a.i./hm2在早稻分蘖盛期施药1次,药后20 d对纹枯病的防效均在57%以上;在晚稻分蘖盛期和孕穗期施药2次,第2次药后12 d对纹枯病的防效均在60%以上,与对照药剂240 g/L噻呋酰胺悬浮剂72 g a.i./hm2处理无显著差异,且对稻曲病具有良好的兼治效果,对稻曲病的病指防效均在73%以上。[结论]腈菌唑适用于水稻纹枯病和稻曲病的防治。     

水稻稻曲病田间人工接种及药剂防治探讨

田间接种试验表明,在水稻孕穗期至破口初期人工接种稻曲病粒浸泡液可显著提高稻曲病发病程度,可提高田间药效试验的可靠性。田间小区试验结果表明,125 g/L氟环唑SC 93.75g/hm~2、75%肟菌·戊唑醇WG 168.75 g/hm~2、36%丙环·咪鲜胺SC 270 g/hm~2等对稻曲病均有较好的防治效果,在水稻破口期前5~7 d施药1次,防治效果在70%左右。430 g/L戊唑醇SC 129 g/hm~2和10%嘧菌酯CS 120 g/hm2防效较低,还需进一步试验。     

不同用药时期6种常用药剂对水稻稻曲病的防治效果研究

通过对不同用药时期6种常用药剂防治水稻稻曲病的研究,明确了250 g/L嘧菌酯SC、430 g/L戊唑醇SC、5%井冈霉素AS和75%肟菌·戊唑醇WG对水稻稻曲病防效较好,防治最佳时间为水稻破口前7 d左右。破口前7 d防治1次的病指防效达到81.41%,显著高于破口期防治1次的防效。破口前7 d和破口期2次用药的防效,与破口前7 d防治1次的防效相比,差异不显著,而与破口期防治1次的防效相比,则差异显著。     

10种杀菌剂防治水稻纹枯病的田间药效比较

为筛选防治水稻纹枯病的高效、低毒及安全药剂,采用GB/T17980.20-2000的方法,对10种杀菌剂防治水稻纹枯病的田间药效进行了试验比较,并增加调查了病株率防效,以供比较参考。结果表明,250 g/L嘧菌酯悬浮剂防治水稻纹枯病防效为87.53%,20%丁香菌酯悬浮剂、25%丙环唑乳油、10%苯醚甲环唑水分散粒剂、80%戊唑醇可湿性粉剂、15%三唑醇可湿性粉剂防效为71.97%～79.59%,70%甲基硫菌灵可湿性粉剂、10%井冈霉素水剂、240 g/L噻呋酰胺悬浮剂防效为63.92%～66.78%,15%咪鲜胺微乳剂防效为46.73%。病株率防效与病情指数防效趋势一致。试验条件下10个供试药剂对水稻无药害。防治水稻纹枯病可以选用嘧菌酯、丁香菌酯、丙环唑、苯醚甲环唑、戊唑醇、三唑醇等新型高效杀菌剂,优先推荐丁香菌酯。为减缓抗性,建议采用药剂复配或轮用技术。     

45%丙环唑水乳剂的研制

介绍了45%丙环唑水乳剂的配制方法,对水乳剂的溶剂、乳化剂、防冻剂以及增稠剂进行了筛选,确定了45%丙环唑水乳剂的配方组成,并对各项性能指标进行了测试。该制剂具有较好的理化稳定性。田间药效试验结果表明,45%丙环唑水乳剂对水稻稻瘟病、稻曲病、纹枯病的防治效果与25%丙环唑乳油防治效果相当。     

50%丙环唑·左旋松油醇乳油的研制

通过筛选试验,确定了50%丙环唑·左旋松油醇乳油的最佳配比为:丙环唑20%,左旋松油醇30%,乳化剂10%,溶剂40%.经稳定性试验,该乳油各项指标符合农药乳油标准.田间试验结果表明,50%丙环唑·左旋松油醇乳油在稀释1000～2000倍条件下可有效防治水稻纹枯病,防效为66.2%～82.0%.     

敌力脱防治水稻中后期病害的初步研究

本文进行了敌力脱（丙环唑）防治水稻中后期纹枯病、叶鞘腐败病、稻田病和稻粒黑粉病的药效试验。结果表明：防治稻纹枯病、稻曲病、稻叶鞘腐败病和稻粒黑粉病的效果分别为７６．０％、１００％、７１．８％和７８．０％。初步认为敌力脱是防治水稻中后期病害较好的药剂，能达到多种病害兼治的目的。     

Miscibility of poly(methoxymethyl methacrylate) and poly(methylthiomethyl methacrylate) with poly(styrene-co-acrylonitrile) and poly(p-methylstyrene-co-acrylonitrile)

The miscibility of poly(methoxymethyl methacrylate) (PMOMA) and poly(methylthiomethyl methacrylate) (PMTMA) with poly(styrene-co-acrylonitrile) (SAN) and poly(p-methylstyrene-co-acrylonitrile) (pMSAN) was studied by differential scanning calorimetry. PMOMA is miscible with SAN having an acrylonitrile (AN) content around 30 wt %. However, PMOMA is immiscible with any of the pMSAN having AN contents between 9 and 36 wt % and with pMSAN having AN contents between 19 and 34 wt %. The miscibility of the blends enables the evaluation of various segmental interaction parameters.     

Rheological behavior of blends of poly(methyl methacrylate) (PMMA) and poly(acrylonitrile-stat-styrene)-graft-polybutadiene (ABS)

The rheological behavior of blends of poly(methyl methacrylate) (PMMA) and poly(acrylonitrile-stat-styrene)-graft-polybutadiene (ABS) was investigated using a cone-and-plate rheometer. The rheological properties measured were shear stress (σ₁₂), viscosity (η), and first normal stress difference (N₁) as functions of shear rate (\documentclass{article}\pagestyle{empty}\begin{document}$ \dot \gamma$ \end{document}) in steady shearing flow, and storage modulus (G′) and loss modulus (G″) as functions of frequency (ω) in oscillatory shearing flow. It has been found that the rheological behavior of blends of ABS and PMMA was very similar to that of blends of poly(styrene-stat-acrylonitrile) (SAN) and PMMA, in that N₁ in logarithmic plots of N₁ versus σ₁₂, and G′ in logarithmic plots of G′ versus G″, vary regularly with blend composition. This has led us to conclude that the rubber particles that are grafted on an SAN resinous matrix in ABS resin plays only a minor role in influencing the compatibility of ABS/PMMA blends, and that the SAN chains attached to the surface of rubber particles, and the SAN matrix phase, play a major role in compatibilizing ABS resin with PMMA.     

Photo-Initiated Lamination of Polyethylene (PE) and Poly(ethylene terephthalate) (PET)

Besides plasma-based processes, photo-initiated surface modifications have an interesting potential for adhesion promotion. This is of special interest with applications ranging from classical finishing to composites. Photo-chemical processes using continuous UV sources — monochromatic as well as broad band — are based on radical activation and ensuing reaction with the atmosphere. Achievable effects are addition of atoms — e.g., introduction of oxygen (photo-oxidation) resulting in increased surface energy — or grafting of functional groups. Both have certain potentials for adhesion promotion in a physico-chemical way. Based on the fundamental scheme of these processes — i.e., a photon-initiated radical reaction at the substrate-atmosphere interface — a direct 'inter-linking' of coating polymer and substrate is presented in this paper. The principal idea is to apply a thin layer of coating polymer on the substrate and irradiate this composite system at certain UV wavelengths. Given a low absorption of the radiation by the thin coating and — at the same time — a high absorption by the substrate, the radiation will penetrate the coating layer and generate radicals at the interface, which will induce cross-linking between the coating polymer and substrate. It is shown that for the example of laminates of polyethylene (PE) film on fabrics made of poly(ethylene terephthalate) (PET), extremely high adhesion strenghths are achieved without any use of additional adhesion promoters.     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998     

Victrex® poly(ethersulfone) (PES) and Victrex® poly(etheretherketone) (PEEK)

Properties of two high performance engineering thermoplastics, amorphous polyethersulfone (PES) and semicrystalline polyetheretherketone (PEEK), are discussed. Both resins can be processed by conventional techniques, compounded with high performance fibers, and have high service temperature (up to 300°C). Due to the amorphous character PES can be dissolved and spray coated into metals.     

Synthesis and properties of ABA-type triblock copolymers of poly(glycolide-co-caprolactone) (A) and poly(ethylene glycol) (B)

Poly(glycolide-co-caprolactone) (A)-poly(ethylene glycol) (B) ABA-type triblock copolymers (PGCE) were synthesized by bulk ring opening polymerization, using the hydroxyl endgroups of poly(ethylene glycol) (PEG) as initiator and stannous octoate as catalyst. The resulting copolymers were characterized by various analytical techniques. Gel permeation chromatographic analysis indicated that the polymerization product was free of residual monomers, PEG and oligomers. ¹H NMR and differential scanning calorimeter results demonstrated that the copolymers had a structure of poly(glycolide-co-caprolactone) (PGC) chains chemically attached to PEG segments. All the PGCE copolymers showed improved hydrophilicity in comparison with the corresponding PGC copolymers with the same molar ratio of glycolidyl and caproyl units. The microspheres of PGCE copolymer exhibited rough surfaces quite different from the smooth surface of PGC microspheres. This phenomenon was attentively ascribed to the highly swollen ability of PGCE copolymers and the freeze-drying process in the microspheres fabrication.     

Finite strain behavior of poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate)-glycol (PETG)

Uniaxial and plane strain compression experiments are conducted on amorphous poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate)-glycol (PETG) over a wide range of temperatures (25-110 °C) and strain rates (.005-1.0 s⁻¹). The stress-strain behavior of each material is presented and the results for the two materials are found to be remarkably similar over the investigated range of rates, temperatures, and strain levels. Below the glass transition temperature (θ_g=80 °C), the materials exhibit a distinct yield stress, followed by strain softening then moderate strain hardening at moderate strain levels and dramatic strain hardening at large strains. Above the glass transition temperature, the stress-strain curves exhibit the classic trends of a rubbery material during loading, albeit with a strong temperature and time dependence. Instead of a distinct yield stress, the curve transitions gradually, or rolls over, to flow. As in the sub-θ_g range, this is followed by moderate strain hardening and stiffening, and subsequent dramatic hardening. The exhibition of dramatic hardening in PETG, a copolymer of PET which does not undergo strain-induced crystallization, indicates that crystallization may not be the source of the dramatic hardening and stiffening in PET and, instead molecular orientation is the primary hardening and stiffening mechanism in both PET and PETG. Indeed, it is only in cases of deformation which result in highly uniaxial network orientation that the stress-strain behavior of PET differs significantly from that of PETG, suggesting the influence of a meso-ordered structure or crystallization in these instances. During unloading, PETG exhibits extensive elastic recovery, whereas PET exhibits relatively little recovery, suggesting that crystallization occurs (or continues to develop) after active loading ceases and unloading has commenced, locking in much of the deformation in PET.     

Thermal studies of blends of poly(phenylene sulfide) (PPS) with poly(phenylene sulfide sulfone) (PPSS) and with poly(phenylene sulfide ether) (PPSE)

The miscibilities of poly(phenylene) sulfide/poly(phenylene sulfide sulfone) (PPS/PPSS) and poly(phenylene) sulfide/poly(phenylene sulfide ether) (PPS/PPSE) blends were invesigated in terms of shifts of glass transition temperatures T_g of pure PPS, PPSS, a dn PPSE. The crystallization kinetics of PPS/PPSS blends was also studied as a function of molar composition. The PPS/PPSS and PPS/PPSE blends are respectively partially and fully miscible. PPSE shows a plasticizing effect on PPS as does PPS on PPSS, which necessarily improves te processibility in the respective systems. We can control T_g and melting temperature T_m of PPS by varying amounts of PPSE in blends. The melt crystallization temperature T_mc of PPS/PPSE blends was higher than that of the PPSE homopolymer. Therefore, these blends require shorter cycle times in processing than pure PPSE. The overall rate of crystallization for PPS/PPSS blends follows the Avrami equation with an exponent ?2. The maximal rate of crystallization for PPS/PPSS blends occurs at a temperatre higher by 10°C than that for PPS, while the crystallization half time t_1/2 is 4 times shorter. In the cold crystallization range, crystal growth rates increase and Avrami exponents decrease significantly as the temperature increases.     

New gold(I) and silver(I) complexes of sulfamethoxazole: Synthesis,X-ray structural characterization and microbiological activities of triphenylphosphine(sulfamethoxazolato-N2)gold(I) and (sulfamethoxazolato)silver(I)

Sulfamethoxazole (SMTZ) reacts with Ph₃PAuCl and AgCl in methanol/triethylamine to give [Ph₃PAu(SMTZ_-1H+)] (SMTZ_-1H+ = sulfamethoxazolato anion) (1) and [Ag(SMTZ_-1H+)] (2). While the lattice of 1 contains single molecules with linear N–Au–P bonds, compound 2 comprises a two-dimensional polymeric assembly of the deprotonated SMTZ ligand and silver ions, which are coordinated by one oxygen and three nitrogens in a distorted tetrahedral array. The microbiologic activities (Mueller–Hinton broth dilution tests) of 1 and 2 were determined in relation to free sulfamethoxazole.