阿维菌素和硫线磷对南方根结线虫的毒力

利用阿维菌素和硫线磷处理南方根结线虫离体卵与幼虫,测试其对线虫卵和卵块孵化以及对2龄幼虫的致死作用、活动能力、侵入能力的影响。结果表明阿维菌素和硫线磷均对线虫卵和卵块的孵化表现很强的抑制作用,阿维菌素5μg/mL处理24 h对卵孵化抑制率高达82.57%,而硫线磷40μg/mL处理24 h对卵孵化抑制率为73.05%;阿维菌素和硫线磷处理48 h对2龄幼虫的LD50分别为7.346 11、3.345 6μg/mL;在阿维菌素2μg/mL和硫线磷3μg/mL处理中,2龄幼虫在沙柱中的平均移动距离仅为0.04 cm和0.05 cm,而对照处理的线虫平均移动距离为1.04 cm;在阿维菌素2μg/mL和硫线磷50μg/mL处理2龄幼虫48 h后,对番茄根部的侵入率为0.12%和0.45%,而空白对照处理线虫的侵入率达21.85%。

毛细管气相色谱法测定蔬菜中残留硫线磷

在气相色谱法测定蔬菜中残留硫线磷中提出了应用石英毛细管色谱柱(DB1701,30 m ×0．32 mm×0．25μm)分离并采用火焰光度检测,取一定量经粉碎的蔬菜试样,用乙腈萃取其中的硫线磷,分取萃取液一份,经氮气吹干后,用丙酮溶解其残渣进行气相色谱测定。方法的检出限为0．01 mg·kg-1,对不同的硫线磷浓度水平下进行精密度试验,测得RSD值在2．55％-11．80％间,用标准加入法测得方法的回收率在84．8％-102．0%间。

血液灌流治疗有机磷中毒对硫线磷及硫酸阿托品吸附作用的实验研究

目的定量研究血液灌流对有机磷农药硫线磷和其解毒药阿托品的吸附作用。方法模拟临床血液灌流装置,对含硫线磷和硫酸阿托品的血样进行灌流吸附,分别用毛细管气相色谱法和高效液相色谱法测定硫线磷和硫酸阿托品的残留量。结果吸附剂用量为0.5g、1.0g、1.5g,包膜活性炭在灌流2.0 h后硫线磷的清除率均能达到90%以上,硫酸阿托品的清除率依次为61.9%、84.9%、88.9%;HA230树脂在灌流1.5h后硫线磷清除率都达到90%以上,硫酸阿托品的清除率也依次高达88.0%、97.2%、98.4%;包膜活性炭灌流3.0h后,硫酸阿托品与硫线磷的比值最高为HP前10.1倍,而HA230树脂最高为HP前6.7倍。结论包膜活性炭和HA230吸附树脂血液灌流1.5h^2.0 h均能清除血中大部分硫线磷,而且均能增加血中硫酸阿托品和硫线磷浓度的比值。

气相色谱法测定柑桔中的硫线磷

报道了毛细管气相色谱法测定柑桔中残留硫线磷的方法。样品以乙腈提取,经石英毛细管气相色谱柱DB-1701分离,火焰光度检测器检测,外标法定量。方法的检出限为0.003mg/kg,相对标准偏差为3.47%—6.10%,加标回收率为80.37%—96.98%。

5%硫线磷颗粒剂对甘薯茎线虫病和蛴螬的防治效果

为了明确5%硫线磷颗粒剂对甘薯茎线虫病和蛴螬的防治效果,采用人工接种的方法,在大田测试了5%硫线磷颗粒剂对甘薯茎线虫病的防治效果,同时在蛴螬重发区对地下害虫的防治效果进行了评价。结果表明:在甘薯栽秧时沟施5%硫线磷颗粒剂,对甘薯茎线虫病和蛴螬均具有良好的防治效果,其中,5%硫线磷颗粒剂用药量60 kg/hm2和45 kg/hm2处理,对甘薯茎线虫病的防治效果分别为96.80%和91.25%,与对照药剂神农丹60 kg/hm2和灭线磷22.5 kg/hm2的防治效果相当,差异不显著;对甘薯蛴螬的防治效果分别为90.94%和78.75%,显著高于其他药剂。在茎线虫病防治田中,同时对地下害虫的为害情况进行了调查,5%硫线磷颗粒剂30～60 kg/hm2的防治效果均达到了90%以上。用5%硫线磷颗粒剂45～60 kg/hm2可以同时有效防治甘薯茎线虫和蛴螬。

钼硫碘纳米线结构特性和化学改性的理论研究(英文)

采用第一性原理密度泛函理论研究了纳米线结构的钼硫碘材料. 结构的理论模拟结果显示, 钼硫碘纳米线机械性能很高, 且其形变过程中显示出一种特殊的磁滞现象. 形成能、投影态密度以及电荷密度的计算结果显示, 使用电负性接近硫的碳元素可对钼硫碘纳米线化学改性同时不失去其良好的结构性能和电子性能. 该结果为化学改性钼硫碘纳米线材料应用于催化提供了依据. 这些钼硫碘纳米线材料将在纳米电子学、纳米机械学、催化、纳米限域等研究中有潜在应用.

■线硫醚在水、土壤及2种蔬菜中的残留检测方法

[目的]本文旨在建立噁线硫醚在水、土壤、黄瓜和辣椒中的残留检测方法。[方法]水样中噁线硫醚用LC-18固相萃取小柱提取、富集;土壤样品采用丙酮和水(体积比为3∶1)超声提取,LC-18固相萃取小柱净化;辣椒样品匀浆后用丙酮超声提取,石油醚萃取净化;黄瓜样品匀浆后用丙酮超声提取时加微量甲酸,石油醚萃取,50 mg N-丙基乙二胺(primary secondary amine,PSA)净化。经前处理的所有样品均采用高效液相色谱-紫外检测器进行定量检测。[结果]高效液相色谱法检测噁线硫醚,在0.01~10.00 mg·L-1内线性关系良好,相关系数(R2)为0.999 8,仪器最低检出限为0.01 mg·L-1。在试验添加浓度范围内,水中噁线硫醚的平均添加回收率为97.38%~100.25%,相对标准偏差(RSD)为1.22%~2.40%;土壤中噁线硫醚的加标平均回收率为92.73%~103.87%,RSD为2.21%~5.63%;黄瓜中噁线硫醚的加标平均回收率为91.83%~103.91%,RSD为1.11%~6.24%;辣椒中噁线硫醚的加标平均回收率为91.06%~106.29%,RSD为0.72%~6.76%。[结论]建立的环境介质和2种蔬菜中噁线硫醚的残留检测方法,其准确度和精密度均能满足环境中农药残留分析的要求。

线-板式脉冲流光放电脱硫反应器电场数值计算

在线 板式非热等离子体脱硫反应器脉冲流光放电机理的基础上,采用波方程进行反应器内时变电场分布计算.数值计算运用时域有限差分(FDTD)法,数值模拟结果为以后的反应器流光放电模拟及结构优化提供依据.

喂线增硫法生产42CrMoS4V钢

生产42CrMoS4V钢时经常出现硫的回收率和硫成分不稳定问题,采用喂线增硫法替代包中加FeS后硫的收得率由35%提高到75%以上,硫成分稳定,钢的纯净度高,力学性能、超声波探伤全部满足顾客要求。

新颖杀线虫剂MCW-2对爪哇根结线虫(Meloidogyne javanica)的防治活性

随着甲基溴等高效土壤熏蒸剂以及非熏蒸杀线虫剂的退出或禁用,当前线虫的防治难度日益加大。由于杀线虫剂市场小于除草剂、杀菌剂和杀虫剂,许多农化企业认为开发新颖杀线虫剂无利可图。此外,对人类与非靶标生物安全的有效物质的开发可行性极低。目前,广泛应用的杀线虫剂有涕灭威、硫线磷、克百威、丙线磷、苯线磷、噻唑磷、

花卉根结线虫病的发生与防治

根结线虫病是分布最广、为害最重的植物寄生线虫之一。对花卉植物进行危害最常见的结根线虫有南方根结线虫、花生根结线虫、爪哇根结线虫和北方根结线虫4种。1发生规律根结线虫要经历卵、幼虫和成虫三个生活时期,植物根系分泌物对根结线虫有很强的吸引力。线虫主要分布在20~30 cm的土层内,尤以20 cm的耕作层内居多。

高硫铝镇静钢中硫元素稳定性控制实践

随着当今汽车工业和机械工业的迅猛发展为含硫铝镇静钢提供了更广阔的市场。河南济源钢铁集团有限公司于 2015 年开始批量生产硫系铝镇静钢,其中具有代表性钢种高硫钢 SAE1141、SH42CrMoA、20MnCr5、C70S6BY 等系列铝镇静钢冶炼工艺开发 ( 硫元素含量 0.045% ~ 0.110%)。针对含硫钢种特别是对硫的工艺控制难度较大,质量要求严格,都是中高端材料附加值的品种。

Differential utilization of cyclic, orthorhombic α- and chain-like polymeric μ-sulfur by Acidithiobacillus ferrooxidans

The differential utilization of cyclic, orthorhombic α-sulfur （α-S） and chain-like polymeric g-sulfur （μ-S） by Acidithiobacillus ferrooxidans was investigated. The growth and sulfur oxidation results indicated that utilization of μ-S by A. ferrooxidans was clearly different from α-S. Even if the planktonic cells were produced, the fall of pH and the rise of sulfate concentration were the same after 300 h on each substrate, the speeds of the planktonic cells increase, pH decrease and sulfate concentration increase in the earlier cultivation stage were faster on polymeric sulfur compared with the orthorhombic form. The adsorption capacity of the cells was higher on μ-S than on α-S, The results of SEM, DRIFTS and XRD analyses indicated that the surfaces of α-S and μ -S were modified differently by cells. Differential expression of 11 selected sulfur adsorption-activation and metabolism relevant genes was detected by RT-qPCR. The results showed that the expression of the hydrophobic substrate transport proteins and the sulfur metabolism related proteins was up-regulated, and the adsorption and activation related proteins were down-regulated when the cells were grown on μS, suggesting that μ-S could be more easily bio-adapted and activated than α-S.

A novel and facile wet-chemical method for synthesis of silver microwires

A novel and facile wet-chemical method for synthesis of silver microwires was developed.The well-defined particles were prepared by adding an iron（Ⅱ） sulfate heptahydrate solution into a silver nitrate solution containing citric acid drop by drop at 50 °C.The resulting products were characterized by scanning electron microscopy and X-ray diffraction.It was found that the particles consisted of numerous silver microwires.The reaction temperature greatly affected the morphologies of the as-prepared particles.Both of the mean length and width of the silver microwires increased with the decrease of the concentration of silver nitrate.And the lower concentration was unfavorable for the formation of more silver microwires.Similar findings were also observed when the concentration of iron（Ⅱ） sulfate was decreased.The amount of citric acid also greatly affected the shape of the as-prepared particles.It was concluded that citric acid was the key role in the formation of silver microwires via the Oswald ripening mechanism.

Heterogeneous catalytic activation of peroxymonosulfate for efficient degradation of organic pollutants by magnetic Cu^0/Fe_3O_4 submicron composites

Magnetic Cu^0/Fe3O4 submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate（PMS） and the degradation of organic pollutants.The as-prepared magnetic Cu^0/Fe3O4 submicron composites were composed of Cu^0 and Fe3O4 crystals and had an average size of approximately 220 nm.The Cu^0/Fe3O4 composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thus induced the rapid degradation of rhodamine B,methylene blue,orange Ⅱ,phenol and 4-chlorophenol.The use of0.1 g/L of the Cu^0/Fe3O4 composites induced the complete removal of rhodamine B（20 μmol/L） in15 min,methylene blue（20 μmol/L） in 5 min,orange Ⅱ（20 μmol/L） in 10 min,phenol（0.1mmol/L） in 30 min and 4-chlorophenol（0.1 mmol/L） in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon（TOC） removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cu^0 or Fe3O4 particles alone.The enhanced catalytic activity of the Cu^0/Fe3O4 composites in the activation of PMS was attributed to the synergistic effect of the Cu^0 and Fe3O4 crystals in the composites.Singlet oxygen was identified as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu^0/Fe3O4 composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate ^1O2,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu^0/Fe3O4 composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.

Electrochemical behaviors of tantalum in anhydrous ethanol containing hydrogen sulfate ions

The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impedance techniques.The results revealed that no active-passive transition is presented in the cyclic voltammogram,and the anodic current density increases with the increase of solution temperature,TBAHS concentration,potential scan rate and water content.The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled.Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low;however,when the potential is higher than a certain value,the current density initially declines to a minimum value and then increases gradually.The resistance of passive film decreases with increasing potential,and inductive loops are presented when the potential is higher than 2.0 V.

Self-heating tendency evaluation of sulfide ores based on nonlinear multi-parameters fusion

In order to reveal the nonlinear dynamics characteristics of unsteady self-heating process of sulfide ores, nine different kinds of sulfide ore samples from a pyrite mine in China were taken as experimental materials and their self-heating characteristics were measured in laboratory. Furthermore, the measured temperature was studied by integrating wavelet transform, nonlinear characteristic parameters extraction and fuzzy comprehensive evaluation. The results indicate that only the ore samples 1, 2, 6 and 9 have obvious self-heating phenomenon, and their self-heating initiative temperatures are 220 ℃, 239 ℃, 220 ℃ and 220 ℃, respectively, which means that they are difficult to produce self-heating under normal mining conditions. The correlation dimension of self-heating process is fraction and the maximum Lyapunov exponent is positive, which means that it is feasible to study the self-heating process based on chaotic dynamics theory. The nonlinearities of self-heating process of these four samples （ore samples 1, 2, 6 and 9） are 0.8227, 0.7521, 0.9401 and 0.8827 respectively and the order of the samples according to these results is： sample 6, sample 9, sample 1, sample 2, which is consistent with the measured results of self-heating characteristics. Therefore, the nonlinearity method can be used to evaluate the self-heating tendency of sulfide ores, and it is an effective verification of the reliability of measured results.

Fe-Mn/Al_2O_3 catalysts for low temperature selective catalytic reduction of NO with NH_3

A series of Fe‐Mn/Al2O3 catalysts were prepared and studied for low temperature selective catalytic reduction （SCR） of NO with NH3 in a fixed‐bed reactor. The effects of Fe and Mn on NO conversion and the deactivation of the catalysts were studied. N2 adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, H2 temperature‐programmed reduction, NH3 temperature‐programmed desorption, X‐ray photoelectron spectroscopy （XPS）, thermal gravimetric analysis and Fourier transform infrared spectroscopy were used to character‐ize the catalysts. The 8Fe‐8Mn/Al2O3 catalyst gave 99%of NO conversion at 150？？ and more than 92.6%NO conversion was obtained in a wide low temperature range of 90–210？？. XPS analysis demonstrated that the Fe3＋was the main iron valence state on the catalyst surface and the addition of Mn increased the accumulation of Fe on the surface. The higher specific surface area, enhanced dispersion of amorphous Fe and Mn, improved reduction properties and surface acidity, lower binding energy, higher Mn4＋/Mn3＋ratio and more adsorbed oxygen species resulted in higher NO conversion for the 8Fe‐8Mn/Al2O3 catalyst. In addition, the SCR activity of the 8Fe‐8Mn/Al2O3 cata‐lyst was only slightly decreased in the presence of H2O and SO2, which indicated that the catalyst had better tolerance to H2O and SO2. The reaction temperature was crucial for the SO2 resistance of catalyst and the decrease of catalytic activity caused by SO2 was mainly due to the sulfate salts formed on the catalyst.