精噁唑禾草灵R-构型体含量的测定

本文采用液相色谱法,对精口恶唑禾草灵的化学含量和对映异构体比例进行定量分析。该方法简单,准确实用。标准偏差为0.40,变异系数为0.44%,平均回收率为99.3%。     

精噁唑禾草灵药效试验总结

概述了精噁唑禾草灵的主要特点及在冬小麦、春小麦、大豆、水稻及中草药等作物上的药效试验情况.     

噁唑禾草灵在小麦及土壤环境中的残留与降解研究

报道了除草剂噁唑禾草灵(骠马)及其代谢产物残留的检测方法,以及在小麦和麦田土壤中的降解规律。在小麦苗期、分蘖末期施药后,骠马在麦苗和土壤中降解较快,半衰期(T1／2)1．5d左右,但代谢物的降解却比母体化合物缓慢,麦苗上的T1/2为3d左右,土壤中为3～5d。无论是在小麦苗期或分蘖末期施药,收获时,骠马及代谢物在麦粒中的残留量均≤0．01mg／kg。     

精噁唑禾草灵6.9%水乳剂防治烟地杂草药效试验

试验结果表明,精噁唑禾草灵6.9%EW1200,1500mL/hm2对禾本科杂草有明显的除草效果,其除草、保产效果明显优于精噁唑禾草灵6.9%EW600、900mL/hm2,稍高于乙草胺50%EC3000mL/hm2,是一种较理想的烟田除草剂。建议使用剂量为精噁唑禾草灵6.9%EW1200、1500mL/hm2和乙草胺50%EC3000mL/hm2,可推广应用。     

精噁唑禾草灵中间体2，6-二氯苯并噁唑合成工艺改进

介绍了以2-巯基-6-氯苯并(噁)唑、氯化亚砜、甲苯、DMF为起始原料制备2,6 -二氯苯并(噁)唑的改进工艺,得到产物的纯度为96%、收率 81.8%以上,具有收率高、反应过程稳定、操作简单、生产成本低等优点.     

10%苄嘧磺隆·精(噁)唑禾草灵悬浮剂高效液相色谱分析

建立了反相高效液相色谱法定量分析混配除草剂制剂中苄嘧磺隆和精噁唑禾草灵的方法。采用Kromasil C18柱(25cm×4.6mm×5μm),流动相为乙腈-水梯度洗脱,检测波长为254nm,线性相关系数为0.9992与0.9996。苄嘧磺隆和精噁唑禾草灵的加标回收率分别为95.8%和95.4%;变异系数分别为0.015和0.016。     

高剂量噁唑禾草灵对麦田大龄杂草药效及安全性

应用高剂量的噁唑禾草灵 安全剂防除麦田大龄禾本科杂草硬草和日本看麦娘。结果表明。用量在90ml／667m^2。总防效达97．2％。用药量≥100ml／667m^2时，防效达100％。对小麦的药害试验表明，。恶唑禾草灵用量在100ml／667m^2以下。药后15d及30d，对小麦生长基本无影响。     

15%精噁唑禾草灵·二氯吡啶酸乳油高效液相色谱分析

建立了一种反相高效液相色谱(RP-HPLC)对除草剂15%精噁唑禾草灵·二氯吡啶酸乳油的定量分析方法.采用C18ODS色谱柱,乙腈-水-醋酸(体积比70:29:1)为流动相,流速1 mL/min.检测波长280 nm.结果显示有2个吸收峰,分别为二氯吡啶酸和精噁唑禾草灵.在0.5～100 mg/L(二氯吡啶酸)和1～200 mg/L(精噁唑禾草灵)质量浓度范围内,标准溶液的质量浓度与吸收峰面积线性关系良好,相关系数r2分别为0.9986、1.0000,重复性SR分别为1.364%、0.651%,准确性分别为98.3%、104.2%.     

氰氟草酯·精噁唑禾草灵混剂在水体中的残留分析方法

建立了同时检测水体中氰氟草酯·精噁唑禾草灵混剂的残留分析方法。结果表明,流动相为甲醇-水(体积比为75∶25),流速0.6mL/min,检测波长233nm,柱温30℃,进样量为20μL;氰氟草酯和精噁唑禾草灵的质量浓度分别在0.095～9.52mg/L和0.114～11.44mg/L范围内时,其质量浓度和峰面积的线性关系良好;样品添加质量浓度在0.01～0.50mg/L范围内,平均添加回收率分别为88.82%～93.04%和96.10%～97.06%。该方法简便,准确度、精密度好,可满足水体中氰氟草酯和精噁唑禾草灵残留量同时分析检测的需要。     

15％精噁唑禾草灵·二氯吡啶酸乳油高效液相色谱分析

建立了一种反相高效液相色谱（RP—HPLC）对除草剂15％精噁唑禾草灵·二氯吡啶酸乳油的定量分析方法。采用C18 ODS色谱柱,乙腈-水-醋酸（体积比70：29：1）为流动相,流速1mL／min,检测波长280nm。结果显示有2个吸收峰,分别为二氯吡啶酸和精噁唑禾草灵。在0．5-100mg／L（二氯吡啶酸）和1-200mg／L（精噁唑禾草灵）质量浓度范同内,标准溶液的质量浓度与吸收峰面积线性关系良好,相关系数r^2分别为0．9986、1．0000,重复性叉分别为1．364％、0．651％,准确性分别为98．3％、104．2％。     

混合培养微生物降解氯氰菊酯的特性研究

通过富集培养,获得了降解氯氰菊酯的混合微生物。结果表明,该混合微生物发挥最优降解力的温度是35℃,pH为7.5,培养时间为72h。氯氰菊酯降解速度和混合培养微生物生长对外加碳源有较强的依赖性。培养液中添加5g.L-1葡萄糖和3g.L-1酵母粉,72h氯氰菊酯去除率可达80%以上,氯氰菊酯降解速率可达0.56mg.L-1.h-1;当氯氰菊酯作为培养菌生长的唯一碳源、氮源和能源时,72h内氯氰菊酯去除率为65%,降解速率为0.45mg.L-1.h-1。     

混菌固态发酵豆渣生产菌体蛋白的研究

对以豆渣为原料,利用混菌固态发酵技术生产菌体蛋白饲料工艺进行了研究。通过L9(3^4)正交试验考察了培养基组成、接种物配比、初始pH值以及培养温度等因素的影响。结果表明：当培养基组成为豆渣：麸皮=8：2,接种物配比为黑曲霉：绿色木霉：啤酒酵母：产朊假丝酵母=1：1：1：3,调节初始pH值5．5,32℃培养72h,豆渣粗蛋白质含量达到28．47％。     

液态混菌发酵豆渣生产多酶菌体蛋白的研究

利用黑曲霉(Aspergillusniger)、绿色木霉(Trichodermaviride)、啤酒酵母(Saccharomycescerevisiae)和产朊假丝酵母(Candiautilis)等菌种,对液态混菌发酵豆渣生产多酶菌体蛋白饲料工艺进行了研究。结果表明当培养基主辅物料质量比为豆渣∶麸皮∶豆粉=8∶2∶0.5,初始pH值为5.5,菌种体积配比为黑曲霉∶绿色木霉∶啤酒酵母∶产朊假丝酵母=1∶1∶1∶3,在32℃下培养72h,豆渣粗蛋白质含量达到29.2%,滤纸酶活为182.7IU/g(干产品),而且产品有啤酒的醇香。     

混合菌群的筛选及其与白腐真菌串联降解石油的效果初探

从江苏油田提供的7个采集点的油污土样中筛选得到石油降解率较高的6株细菌--X-5、X-12、X-13、X-21、X-22、X-23和1株真菌--Z-26,通过两两混合实验发现X-23与X-5、Z-26具有较好的协同作用,将三者按1:1:1组成得到石油降解率较高的混合菌群,其石油降解率为75.9%.为进一步降低残留的石油含量,引入了1株白腐真菌进行后期处理,使得水相中石油含量降低,颜色明显变浅.利用气相色谱分析经混合菌和白腐真菌降解前后石油成分的变化,结果发现,石油中正构烷烃得到了有效的降解,除C17和C18外,其它正构烷烃峰峰值均明显降低,甚至消失.     

Biodegradation of phenol in the presence of heavy metals

A microbial growth model was presented for estimating the dynamic behavior of cell growth and substrate consumption in the biodegradation of phenol containing a heavy metal, such as zinc or copper ions. The application of the model for experiments in a batch culture and a continuous culture was examined. The values calculated according to the model corresponded satisfactorily with experimental data, such as the optical density of cells and the concentration of phenol. Using the model, the stability of steady states in a continuous culture was analytically evaluated based on the eigenvalues. The steady states were separated into three categories: (i) a stable steady state where phenol was consumed, (ii) an unstable steady state where phenol was consumed, and (iii) a washout state where phenol was not consumed. The number, kind, and stability of steady states varied significantly with operational conditions such as dilution rate, feed concentration of phenol, and feed concentration of heavy metal ions. The operational conditions required to obtain the stable steady state where phenol was consumed are shown graphically. © 2000 Society of Chemical Industry     

Impact of Acetate in Reduction of Perchlorate by Mixed Microbial Culture under the Influence of Nitrate and Sulfate

The biological reduction of slow degradation contaminants such as perchlorate (ClO₄⁻) is considered to be a promising water treatment technology. The process is based on the ability of a specific mixed microbial culture to use perchlorate as an electron acceptor in the absence of oxygen. In this study, batch experiments were conducted to investigate the effect of nitrate on perchlorate reduction, the kinetic parameters of the Monod equation and the optimal ratio of acetate to perchlorate for the perchlorate reducing bacterial consortium. The results of this study suggest that acclimated microbial cultures can be applied to treat wastewater containing high concentrations of perchlorate. Reactor experiments were carried out with different hydraulic retention times (HRTs) to determine the optimal operating conditions. A fixed optimal HRT and the effect of nitrate on perchlorate reduction were investigated with various concentrations of the electron donor. The results showed that perchlorate reduction occurred after nitrate removal. Moreover, the presence of sulfate in wastewater had no effect on the perchlorate reduction. However, it had little effect on biomass concentration in the presence of nitrate during exposure to a mixed microbial culture, considering the nitrate as the inhibitor of perchlorate reduction by reducing the degradation rate. The batch scale experiment results illustrated that for efficient operation of perchlorate reduction, the optimal acetate to perchlorate ratio of 1.4:1.0 would be enough. Moreover, these experiments found the following results: the kinetic parameters equivalent to Y = 0.281 mg biomass/mg perchlorate, K_s = 37.619 mg/L and q_max = 0.042 mg perchlorate/mg biomass/h. In addition, anoxic–aerobic experimental reactor results verify the optimal HRT of 6 h for continuous application. Furthermore, it also illustrated that using 600 mg/L of acetate as a carbon source is responsible for 100% of nitrate reduction with less than 50% of the perchlorate reduction, whereas at 1000 mg/L acetate, approximately 100% reduction was recorded.     

Biodegradation Behavior of DOC Isolated Mixed Proteins-Based Plastic Sheets

The biodegradability of plastic sheets made of mixed proteins was investigated. Soybean, castor and rapeseed DOC (Deoiled Cake) isolated proteins-based plastic sheets were subjected to microbial degradation using Pseudomonas aeruginosa. Results from the microbial degradation showed that plastic sheets prepared from mixture of soybean, castor and rapeseed proteins could support the growth of P. aeruginosa. Biodegradable plastic sheet with composition (80:10:10 and 60% PEG₄₀₀) degraded much faster than the other four biodegradable plastics sheets under the conditions examined, suggesting that the biodegradability of protein films is associated with the film composition and the extent of covalent cross-linking.     

微生物降解含聚污水的研究进展

主要介绍了微生物降解聚丙烯酰胺的优势、机理,讨论了微生物降解聚丙烯酰胺的影响因素,综述了微生物降解聚丙烯酰胺的国内外研究进展,指出了其在实际应用中存在的不足.     

利用混合二元酸合成混合酸二甲酯和聚酯多元醇的研究

以工业副产物C4～C6混合二元酸为原料,采用传统催化剂浓硫酸合成混合酸二甲酯(DBE),确定了最优工艺条件:以100 g混合二元酸为基准,浓硫酸用量2 mL,回流分水3.5 h,醇酸比5∶1,带水剂甲苯50 mL,酯化后反应液在70～80 ℃下搅拌10 min条件下用Na2CO3溶液洗涤.在此条件下产品酸值小于1 mg KOH/g,其中混合二元酸二甲酯含量大于95%,平均产率为86.3%,质量稳定.自制DBE和1,4-丁二醇在钛酸四正丁酯催化作用下可合成聚氨酯用聚酯多元醇,分子量在800～2 000可控.     

Biodegradation of coals

Selected strains of bacteria [from the Brookhaven National Laboratory (BNL) collection], capable of degrading heavy crude oils, were used to treat bituminous and lignite coals. Products resulting from biochemical reactions among several microorganisms and different coals were examined by pyrolysis gas chromatography-mass spectrometry (Py. g.c.-m.s.), and X-ray absorption near edge structure (XANES) spectroscopy. The results indicated considerable variations in the organic sulfur as well as modifications in coal structure. Furthermore, biochemical reactions involved in the microbial interactions with coals appeared to be microbial species dependent.