含湿Ca(OH)2颗粒脱硫反应特性的模型研究

在半干法脱硫装置中脱反应主要表现为湿Ｃａ（ＯＨ）２颗粒与ＳＯ２的反应，在液相反应溶解和传质理论基础上，通过对含湿Ｃａ（ＯＨ）２颗粒内反应机理的研究分析提出了含湿Ｃａ（ＯＨ）２颗粒相比发生明显变化。     

甲硫醚废气制取二甲基亚砜技术研究

选择双氧水作氧化剂，将具有恶臭气味的涕灭威生产的副产物甲硫醚氧化成无臭的二甲基亚砜。通过实验，优化了工艺条件，减少了安全隐患，提高了二甲基亚砜的产率，消除了恶臭污染。     

Wild tomato leaf extracts for spider mite and cowpea aphid control

Glandular trichomes on the leaves of wild tomato, L. hirsutum f. hirsutum Mull, also known as Solanum habrochaites (Solanaceae), synthesize and accumulate high levels of methyl ketones (MKs). L. hirsutum accession LA 407, having high concentration of MKs, was grown from seeds under greenhouse conditions. Four MKs (2-undecanone, 2-dodecanone, 2-tridecanone, and 2-pentadecanone) were screened for their toxicity to spider mites, Tetranychus urticae Koch and cowpea aphids, Aphis craccivora Koch. The objectives of this investigation were to: (1) develop a bioassay for testing MKs on spider mite and cowpea aphid mortality and (2) compare the efficacies of wild tomato leaf crude extracts and pure standard materials of MKs against spider mite and cowpea aphid mortality. Our results revealed that spider mites are most sensitive to 2-tridecanone (LC₅₀ = 0.08 μmole cm^?2 of treated leaf surface) and least sensitive to 2-undecanone (LC₅₀ = 1.5 μmole cm^?2 of treated leaf surface) 4 h after treatment. Similarly, 2-tridecanone caused greatest mortality (LC₅₀ = 0.2 μmole cm^?2 of treated leaf surface), whereas 2-undecanone caused the lowest morality (LC₅₀ = 0.48 μmole cm^?2 of treated surface) of cowpea aphid. We concluded that all MKs tested in this investigation are toxic to spider mites and aphids. 2-Tridecanone is more effective in killing mites and aphids compared to other MKs. Toxicity of crude extracts, prepared from the leaves of L. hirsutum accession LA 407, to spider mites and cowpea aphids revealed greater mortality compared to a combined mixture of MKs standard material (used at the same concentration as found on LA 407 leaves). This indicates that in addition to MKs, other unidentified compounds in LA 407 leaf extract also have pesticidal properties. Accordingly, leaf extracts of LA 407 could be explored in crop protection, and they might open a new area of MK formulations and discovery of biorational alternatives for pest control in agricultural fields.     

The structure of the fire fighting foam surfactant Forafac®1157 and its biological and photolytic transformation products

For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by ¹H, ¹³C and ¹⁹F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility.     

Screening Capsicum Accessions for Capsaicinoids Content

Ninety Capsicum accessions selected from the USDA Capsicum germplasm collection were screened for their capsaicinoids content using gas hromatography with nitrogen phosphorus detection (GC/NPD). Fresh fruits of Capsicum chinense, C. frutescens, C. baccatum, C. annuum, and C. pubescens were extracted with methanol and analyzed for capsaicin, dihydrocapsaicin, and nordihydrocapsaicin. Mass spectrometry of the fruit crude extracts indicated that the molecular ions at m/z 305, 307, and 293, which correspond to capsaicin, dihydrocapsaicin, and nordihydrocapsaicin, respectively, have a common benzyl cation fragment at m/z 137 that can be used for monitoring capsaicinoids in pepper fruit extracts. Capsaicin and dihydrocapsaicin were the dominant capsaicinoids detected. Capsaicin concentrations were typically greater than dihydrocapsaicin. Concentrations of total capsaicinoids varied from not detectable to 11.2 mg fruit^?1. Statistical analysis revealed that accession PI-441624 (C. chinense) had the highest capsaicin content (2.9 mg g^?1 fresh fruit) and accession PI-497984 (C. frutescens) had the highest dihydrocapsaicin content (2.3 mg g^?1 fresh fruit). Genebank accessions PI-439522 (C. frutescens) and PI-497984 contained the highest concentrations of total capsaicinoids.     

选择性非催化还原法烟气脱硝工业试验

以氨水作为还原剂，在日产5kt的新型干法水泥生产线分解炉上进行选择性非催化还原脱硝工艺的工业性试验研究。在氨水质量分数为13.0%、喷入点温度为894℃、n（NH₃）∶n（NO_x）为1.2、雾化压力为0.35MPa的条件下，NO_x去除率最高，为72.8%，剩余NO_x质量浓度为196mg/m³，剩余NH₃质量浓度小于0.9mg/m³，远低于《水泥工业大气污染物排放标准》征求意见稿中限定的NO_x和NH₃质量浓度。     

Leaching,mobility and persistence of tebufenozide in columns packed with forest litter and soil

Abstract

Leaching, downward mobility and persistence of tebufenozide was investigated under laboratory conditions in columns packed with forest litter and soil, after fortification with the analytical grade material (purity > 99.6%) and with two commercial formulations, RH‐5992 2F (aqueous flowable) and RH‐5992 ES (emulsion suspension). Two types of litter and soil were used: one type with relatively high amounts of sand and the other with high amounts of clay.

The concentrations eluted in the leachates were lower when the analytical material (dissolved in acetone) was used for fortification, than when the two formulations (diluted with water) were used. The amount leached was higher for RH‐5992 2F than for RH‐5992 ES. The type of substrate, i.e., sandy or clay type, had only marginal influence on the amounts eluted in the leachates. Downward movement of tebufenozide from the top 2‐cm layer to the untreated middle and bottom layers (3‐cm segments) was consistently lower when the analytical material was used for fortification, than when the two formulations were used. Downward movement was higher for RH‐5992 2F than for RH‐5992 ES. Persistence of tebufenozide in substrates, maintained under submerged conditions for 70 days after leaching, indicated an initial 2‐week lag period prior to the onset of degradation. Formulation‐related differences were observed in the half‐life (DT₅₀) values. When the analytical material was used for fortification, the DT₅₀ ranged from ca 54 to 59 d. However, when the formulations were used for fortification, the DT₅₀ showed a higher range, i.e., from ca 62 to 67 d for RH‐5992 2F and ca 70 to 80 d for RH‐5992 ES. Formulation ingredients appear to have caused enhanced adsorption of tebufenozide onto the substrates, thus delaying degradation.     

Oviposition of carrot fly (Psila rosae) in response to foliage and leaf surface extracts of host plants

Summary. Foliage of twelve host and two non-host species and surrogate leaves treated with the respective leaf extracts were presented to laboratory populations of the carrot fly (Psila rosae) in oviposition choice assays. The stimulatory activity of dichloromethane surface extracts and the diethyl ether fraction of hot water extracts did not reflect accurately the differences in acceptability observed among intact leaves. A better correlation was found using hexane extracts prepared in a microwave oven. Two out of five fractions of this crude hexane extract obtained by silica gel column chromatography stimulated oviposition. The diethyl ether fraction, which contained the previously identified oviposition stimulants (propenylbenzenes, furanocoumarins, polyacetylenes), could account for only a minor part of the variation in the acceptability of host leaves. The preference hierarchy for intact leaves corresponded better to the ranking of species according to activity of the methanolic fraction, which apparently contains unknown stimulatory compounds.? The water fractions of the hot water extracts were shown to reduce egg-laying underneath surrogate leaves treated with a stimulatory extract. This oviposition-deterring effect was particularly strong with the non-preferred species Pimpinella major, which is also highly resistant in the field. Hence, unidentified inhibitory compounds may also contribute to differential accept ability of host plants. It is concluded that antixenotic (non-preference) resistance of host plants to carrot fly attack depends on complex mixtures of semiochemicals. Received 11 June 1997; accepted 26 November 1997.     

Photolysis of the herbicide bispyribac sodium in aqueous medium under the influence of UV and sunlight in presence or absence of sensitizers

The photolysis of a rice herbicide Bispyribac sodium (Sodium 2, 6-bis [(4, 6-dimethoxypyrimidin-2-yl) oxy] benzoate) has been studied in different aqueous medium (distilled water, pond water and Irrigation water) under the influence of UV (λ max ≥ 250 nm) and sunlight in presence or absence of sensitizers (TiO₂ and KNO₃). The study was conducted under laboratory simulated condition which made it possible to evaluate the contribution of different factors viz. source of irradiation, solvent and sensitizers towards the photolysis of bispyribac sodium. The photodegradation proceeds via first order reaction Kinetics in all the cases. Five photo metabolites (M₁-M₅) were isolated in pure form by column chromatographic method from the irradiation system under UV influenced and TiO₂ as sensitizer. From the different spectral data (IR, NMR, UV-VIS, Mass) the structure of these five metabolites were assigned as M₁ (Phenol), M₂ [2, 6-Dihydroxy benzoic acid], M₃ [2, 6-bis [(4, 6 dimethoxypyrimidin-2yl) oxy] benzoic acid], M₄ [2-(3-Hydroxy-phenoxy)-pyrimidine-4, 6-diol] and M₅ as [2,4-Dihydroxy-3, 5-dimethoxy-6-(4-methoxy pyrimidine-2-yloxy)-benzoic acid]. Moreover, another six photometabolites (M₆-M₁₁) were identified from the different irradiation system on the basis of Micromass analysis. On the basis of MS/MS data analysis, the structure of these six photometabolites were assigned as M₆ [2-(4, 6-Dimethoxy-pyrimidin-2-yloxy)-6-hydroxy-benzoic acid], M₇ [2-Hydroxy-6-(4-hydroxy-6-methoxy-pyrimidin-2-yloxy)-benzoic acid], M₈ [4, 6-Dimethoxy-pyrimidin-2-ol], M₉ [6-Methoxy-pyrimidine-2, 4-diol], M₁₀ [2-Hydroxy-6-(pyrimidin-2-yloxy)-benzoic acid] and M₁₁ [2, 4, 6-Trimethoxy-pyrimidine]. The plausible Photodegradation pathways of bispyribac sodium in the present investigation were portrayed which proceeds via hydrolysis, hydrolytic cleavage, O-dealkylation, decarboxylation, dehydroxylation, O-alkylation and hydroxylation.     

Natural Products: Repellency and Toxicity of Wild Tomato Leaf Extracts to the Two-Spotted Spider Mite,Tetranychus urticae Koch

The potential of using phytochemicals from leaves of wild tomato for controlling the two-spotted spider mite, Tetranychus urticae Koch, is explored in this study as a promising alternative to the use of synthetic pesticides. Wild tomato accessions of Lycopersicon hirsutum plants that are not consumed by humans were planted under greenhouse conditions for mass production of leaves. Crude extracts from leaves of three accessions of L. hirsutum, six accessions of L. hirsutum f. glabratum, and one accession each of L. pennellii and L. pimpinellifolium were prepared in chloroform, ethanol and hexane. Two spider mite bioassays, one a measure of antibiosis and the other a measure of repellency, were utilized to determine the acaricidal performance of the crude extracts. The bioassay for antibiosis was a 6-h no-choice test. The bioassay for repellency utilized a ring bioassay. Chloroform leaf extracts of L. hirsutum f. glabratum accessions (PI-251304, PI-134417, PI-134418, and PI-126449) exhibited greatest antibiotic activity on two-spotted spider mites; the hexane extracts exhibited greatest repellency. Extracts from PI-251304, PI-126449, PI-134417, and PI-134418 were especially lethal (chloroform) or repellent (hexane). We investigated differences in chemical composition of the crude leaf extracts that may explain the observed differences in mortality and repellency among the different accessions. Major chemical compounds (α -curcumene, α -zingiberene, trans-caryophyllene, 2-undecanone, and 2-tridecanone) known to have pesticidal efficacy were detected and quantified in the crude leaf extracts using a gas chromatograph (GC) equipped with a mass spectrometer (GC/MS). Lethality of extracts was mainly associated with the presence of high concentrations of 2-tridecanone; repellency of extracts was mainly associated with the presence of trans-caryophyllene. Leaf extracts of L. hirsutum f. glabratum accessions that contain significant quantities of 2-tridecanone and/or trans-caryophyllene could be useful for managing populations of spider mites, which could reduce reliance on synthetic pesticides.