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441.
442.
对印染废水治理的几点思考 总被引:6,自引:0,他引:6
结合轻工纺织化纤类环评工程师登记培训及日常工作中有关印染废水治理的一些经验和做法,分析探讨了目前印染废水处理工艺技术中存在的问题,诸如提高印染废水的可生化性、降低活性污泥的产量、以及碱减量、退浆废水局部预处理、色度去除的专项处理等问题,提出了可行的解决方案。 相似文献
443.
单甲脒在土壤中的吸附 总被引:20,自引:2,他引:20
用批量平衡法研究了单四脒酸盐的活性部分-单甲脒在不同类型土壤中的吸附行为,获得了单甲脒的单位土壤有机质吸附常数(Kom)为284和吸附自由能变化量为13.99kJ.mol^-1的实验数值,研究表明,单甲脒在土壤中吸附符合Freundlich经验公式,其在土壤中的吸附系数Kd与土壤中有机质含量和阳离了交换容量均显著正相关。 相似文献
444.
Yorianta?Sasaerila Regine?Gries Gerhard?Gries Grigori?Khaskin Skip?King Stephen?Takács Hardi?) 《Chemoecology》2003,13(2):89-93
Summary. During peak calling activity by male oil palm bunch
moths, Tirathaba mundella Walker (Lepidoptera: Pyralidae), their
hairpencils, wings or entire body were extracted in hexane. Gas
chromatographic-electroantennographic detection (GC-EAD) analyses of
hair pencil extracts revealed four compounds that consistently elicited
responses from female antennae. The NMR spectrum of isolated compound 1,
and mass spectra and retention indices of compounds 1–4 suggested that
they were (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydro-pyran-3-ol (1),
4-hydroxy-3-methoxy-benzaldehyde (2, vanillin),
6,10,14-trimethyl-2-pentadecanone (3), and
6,10,14-trimethyl-2-pentadecanol (4). Comparative GC and GC-MS analyses
of hair pencils extract and synthetic standards confirmed these
structural assignments. Moreover, comparative chromatography of
synthetic and hairpencil-isolated 1 on a Cyclodex-B column (which
separated the four stereoisomers with baseline resolution) revealed that
male T. mundella produce the SS-stereoisomer (SS-1). In field cage
bioassay experiments in Palembang, Indonesia, synthetic SS-1 and
vanillin in combination, but not singly, attracted female T. mundella.
SS-1 plus vanillin were as effective as male T. mundella in attracting
females. Compounds 3 and 4 did not enhance the blend's attractiveness.
Received October 11 2002; accepted March 14, 2003.
R1D="
Correspondence to: Gerhard Gries, email: gries@sfu.ca 相似文献
445.
蔬菜地土壤磷提取及模拟径流中磷素潜在流失的影响 总被引:1,自引:1,他引:1
蔬菜地磷素流失是一种典型农业非点源污染类型。通过观测地表径流中溶解态反应磷(DRP)、生物可利用磷(BAP)可以监测土壤磷素流失程度。受到各种客观条件的限制,这两个指标比较难于获取,而土壤中的总磷(TP)、Olsen(OP)、Mehlich-1(M-1P)和水溶性磷(Pw)可以通过常规分析手段获取。本文选取27个典型蔬菜样地,分析测定各样地土壤中的总磷(TP)、Olsen(OP)、Mehlich-1(M-1P)和水溶性磷(Pw)四个磷提取变量,采用了经典方法计算土壤磷流失潜能指标——磷吸持饱和度(DPS)。同时采用模拟径流实验得出典型蔬菜样地地表径流样中溶解态反应磷(DRP)、生物可利用磷(BAP)。结果表明:M-1P、Pw与DPS呈极显著正相关,相关系数分别达到了0.85和0.74(p<0.01);而M-1P、Pw与DRP浓度相关系数(r2=0.843和0.786,p<0.01)大于TP、OP与DRP浓度的相关系数(r2=0.554和0.722,p<0.01)。结论认为,通过测定M-1P、Pw和计算DPS能比较准确、便捷地预测土壤径流磷素流失风险程度。 相似文献
446.
臭氧氧化降解水溶液中1—萘酚的动力学研究 总被引:10,自引:0,他引:10
本文研究了水溶液中1-萘酚在鼓泡反应釜内臭氧氧化的消失动力学,考察了pH值、温度、自由基清除剂和1-萘酚的起始反应浓度等因素对反应的影响。结果表明,pH值、反应温度的提高有利于1-萘酚的降解。1-萘酚初始浓度低时其消失速率较高。该反应是有自由基反应贡献的分子臭氧氧化反应。在重碳酸盐存在下,1-萘酚的臭氧氧化降解符合一级反应动力学。 相似文献
447.
Summary. Host selection in tree-killing bark beetles
(Coleoptera: Scolytidae) is mediated by a complex of semiochemical
cues. Using gas chromatographic-electroantennographic
detection (GC-EAD) and GC-mass spectrometric
analyses, we conducted a comparative study of the electrophysiological
responses of four species of tree-killing bark
beetles, the Douglas-fir beetle, Dendroctonus pseudotsugae,
Hopkins, the mountain pine beetle, D. ponderosae Hopkins,
the spruce beetle, D. rufipennis Kirby, and the western balsam
bark beetle, Dryocoetes confusus Swaine, to volatiles
captured by aeration of 1) bole and foliage of four sympatric
species of conifers, Douglas-fir, Pseudotsuga menziesii
(Mirb.) Franco, lodgepole pine, Pinus contorta var. latifolia
Engelm., interior spruce, Picea engelmannii x glauca, and
interior fir, Abies lasiocarpa x bifolia, and 2) con- and
heterospecific beetles at three stages of attack. We identified
13 monoterpenes in the conifers and nine compounds in the
volatiles of beetles that elicited antennal responses. There
was no qualitative difference in the terpene constitution of
the four species of conifers and very little difference across
beetle species in their antennal response to compounds from
conifers or beetles. The lack of species-specific major or
minor components in conifers suggests that beetles would
need to detect differences in the ratios of different compounds
in conifers to discriminate among them. Attraction to
hosts and avoidance of nonhost conifers may be accentuated
by perception of compounds emitted by con- and heterospecific
beetles, respectively. The 22 compounds identified
are candidate semiochemicals with potential behavioural
roles in host location and discrimination. 相似文献
448.
广州城郊菜地土壤磷素特征及流失风险分析 总被引:5,自引:1,他引:5
通过化学分析和土壤淋洗试验对广州城郊菜地土壤磷素特征和流失风险进行了研究和分析。结果表明.广州城郊菜地土壤全磷含量极高;与自然土壤相比较,菜园土壤无机磷比例增大、有机磷比例降低;无机磷中的AI-P、Fe-P比例增加.O-P比例降低,Ca-P比例基本一致;土壤Olsen P、Bray-1 P、Mehlich-1 P、0.01mol/L CaCl_2和H_2O提取的磷含量相当高;土壤淋洗液中溶解态磷和总磷持续保持很高的浓度,土壤磷供应强度大。菜园土壤中磷进入水体引起水体磷浓度增加,导致水体富营养化风险大;土壤磷的测定值可作为土壤磷流失风险和对水环境影响程度的评估依据。菜地应作为农业非点源磷污染的优先控制区、应通过严格控制磷肥的投入和合理施肥等控制磷的流失。 相似文献
449.
分析了采用叠氮化钠修正法测定水中溶解氧时,对水中亚硝酸根含量与叠氮化钠加入量的关系。 相似文献
450.
Nataliya Voloshchuk Mona Knop Thomas Colby Erich Kombrink Lothar Hennig Diana Hofmann Dieter Sicker Andrej Gryganski Margot Schulz 《Chemoecology》2007,17(1):1-12
Summary. Doratomyces stemonitis (Hyphomycetales, Dematiaceae) is a saprotrophic fungus belonging to the mycobiota of the cereal rhizosphere. The fungus is
able to metabolize benzoxazolin-2-(3H)-one and a variety of its derivatives including higher plant detoxification products, microbial degradation products and
the chemically rather stable 2-amino-(3H)-phenoxazin-3-one. D. stemonitis can use all of these compounds as sole C-sources but their utilization, especially that of microbial degradation products
and 2-amino-(3H)-phenoxazin-3-one, seems to be highly energy consuming, resulting in slow mycelium growth and a change of colony morphology.
Benzoxazolin-2-(3H)-one derived compounds induce the synthesis of different isoforms of a glycosylated protein with sequence homologies to the
endo-1,3-β-glucanase Asp f2, an allergen from Aspergillus fumigatus and other Asp f2-like proteins e.g., from Verticillium dahliae or PRA1 antigen from Candida albicans. The induction of the protein is regarded as a stress response. 相似文献