同步超声衍生萃取土壤中氯代酸性有机物

建立了土壤中酸性有机物的同步衍生萃取分析方法,实现了溶剂体积与土壤质量1:1萃取。将土壤、石英砂、Na4-EDTA和纯水充分混合,室温放置36 h左右使酸性有机物释放,并使水分挥发。将该状态的土壤置于衍生瓶,加入丙酮、五氟苄基溴溶液和K2CO3溶液,利用超声技术将酸性有机物的萃取和衍生同时完成,超声时间为30 min时达到最佳萃取衍生效果。萃取液用硅胶柱净化后,用气相色谱-负化学源质谱(NCI)11 min内完成检测。在5.0~250.0μg/L线性范围内,各组分线性系数r2>0.997,检出限在1.2~4.8μg/kg之间,加标回收率在66.2%~102.9%之间,相对标准偏差在8.4%~13%之间。用该技术对土壤样品分析取得满意结果。

Organic Acids Secreted from Plant Roots under Soil Stress and Their Effects on Ecological Adaptability of Plants

[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.

Effects of Bagging with Paper Bags and Non-woven Bags on Flavor Compounds of Feicheng Peach

With Hongli Feicheng Peach as the test material, the effects of bagging with 4 kinds of paper bags and 3 kinds of non-woven bags on the soluble sugar, organic acids and aroma compounds in peach fruits were investigated using headspace solid-phase microextraction （HS-SPME） combined with gas chromatogra- phy-mass spectrometry （GC-MS） and high-performance liquid chromatography （HPLC）. The results showed that there were significant differences in sugar and acids contents of peach fruits between different bagging treatments. The sugar con- tent of peach fruits was increased when bagged with single-layer inner-black outer- yellow paper bags and double-layer inner-white outer-yellow paper bags. The organ- ic acid content in peach fruits bagged with all the types of bags except the single- layer inner-black outer-yellow paper bag was increased greatly. The count and rela- tive content of aroma compounds were all decreased after bagging. Combined with the detection results of soluble sugar, organic acids and aroma compounds, the sin- gle-layer inner-black outer-yellow paper bag was suitable for bagging of Hongli Fe- icheng peach.

Effect of Furfural Residue on Control of Soil Alkalization and Amelioration of Solonetz

Furfural residue, an industrial waste, is a kind of strongly acidic organic materials. Its comprehensive utilization in agriculture showed a significant effect on control of soil alkalization, amelioration of solonetz and increase of crop yields. In detail it may adjust pH, depress alkalinity, reduce bulk density and compactness and increase water permeability and retention ability of the soil. Meanwhile agricultural use of furfural residue provided an effective way to avoid its pollution of the soil, Water and air.

Effects of Different Irrigation Modes on Internal Quality of Flue-cured Tobacco Leaves

[Objective] This study aimed to investigate the effects of different irrigation modes on chemical constituent and aroma substance contents and sensory quality in flue-cured tobacco leaves. [Method] Field experiments were conduced with two treatments, including watering irrigation and micro-spraying irrigation. In watering irrigation treatment, flue-cured tobacco seedlings were respectively watered by artificial root irrigation once at rosette stage（May 26） and vigorous growth stage（June 18）, 1kg/plant each time; in micro-spraying treatment, flue-cured tobacco seedlings were watered by artificial root irrigation once at rosette stage（May 26）, 1 L/plant. [Result]Compared to watering irrigation mode, micro-spraying irrigation could extremely significantly increase the content of main aromatic substance in middle and upper leaves.Contents of main aromatic substance non-volatile organic acids, volatile organic acids, petroleum ether extracts, neophytadiene and neutral aromatic substances in C3F tobacco leaves were improved by 24.4%, 32.6%, 20.7%, 33.8% and 26.3%, respectively; contents of main aromatic substance non-volatile organic acids, volatile organic acids, petroleum ether extracts, eophytadiene and neutral aromatic substances in B2F tobacco leaves were improved by 16.3%, 6.0%, 6.1%, 10.8% and8.1%, respectively. In addition, micro-spraying irrigation could extremely significantly reduce the nicotine content in middle and upper leaves and improve the aromatic coordination, mellow taste and smoldering property. [Conclusion] In flue-cured tobacco production, micro-spraying technology is an important means to improve the internal quality of flue-cured tobacco leaves, which can be adopted to effectively solve the problem of declining quality of flue-cured tobacco leaves resulted from the dry climate at maturation stage in seasonal frequent-drought areas.

Toxic Effects of Phthalates on Ocean Algae

This article discusses the interaction of phthalates and ocean algae based on the standard appraisal method of chemical medicine for algae toxicity. Through the experiments on the toxic effects of dimethyl (o-) phthalate (DMP), diethyl (o-) phthalate (DEP), dibutyl (o-) phthalate (DBP) on ocean algae, the 50 % lethal concentration of the three substances in 48 h and 96 h for plaeodectylum tricornutum, platymonas sp, isochrysis galbana, and skeletonema costatum is obtained. Tolerance limits of the above ocean algae of DMP, DEP, and DBP are discussed.

Effects of Urechis unicinctus Juveniles on Chemical Characteristics of Organically Contaminated Coastal Sediment

Biological activities of marine benthos such as burrowing and feeding may change sediment characteristics.We conducted three experiments to examine the potential of using juveniles of a spoon worm Urechis unicinctus to improve the quality of organically contaminated coastal sediment.Sediment samples were collected from a site that was heavily contaminated with organic matter (Seonso) and two sites that were clean (Myo-do,Dolsan-do).Urechis juveniles,obtained by artificial fertilization and cultured in the laboratory,were introduced to the sediment (weight 3 kg,depth 10 cm) at a density of 500 individuals per aquarium (length 50 cm,width 35 cm,height 30 cm) (Experiment 1),or at densities ranging from 100 to 900 individuals per beaker (Experiment 2).To examine how sediment contamination can be modified by the effects of Urechis,500 individuals (per aquarium) were exposed to the Seonso contaminated sediment that had been mixed with 0-100% clean sand (Experiment 3).Each experiment lasted two months and sediment samples were collected every 15 d to determine the several indexes of sediment quality,which included acid volatile sulfide (AVS),chemical oxygen demand (COD) and total ignition loss (TIL).In Experiment 1,the existence of Urechis did not result in significant changes in quality indexes in the sediments collected from Myo-do,Dolsan-do.However,AVS,COD and TIL of the Seonso sediment all decreased significantly after co-incubation with Urechis juveniles for 30 to 45 d.Experiment 2 showed that a density of at least 300 juveniles per beaker was necessary to significantly reduce all three quality indexes,and the magnitude of reduction was positively correlated with juvenile density.Experiment 3 revealed that Urechis juveniles were effective in reducing the AVS,COD and TIL of the Seonso sediment that had been mixed with 60%,80%,and 80% of clean sand,respectively.The results of the present study therefore indicated that juveniles of this spoon worm have the potential to be used to improve the quality of organically contaminated sediment in coastal waters.

Ethyl and butyl acetate oxidation over manganese oxides

Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional methods and all specimens were applied to the oxidation of ethyl acetate and butyl acetate,acting as models for the volatile organic compounds found in industrial emissions.The catalysts were also characterized using N2adsorption,X‐ray diffraction,scanning electron microscopy,temperature programmed reduction and X‐ray photoelectron spectroscopy.Each of the manganese oxides was found to be very active during the oxidation of both esters to CO2,and the synthesis methodology evidently had a significant impact on catalytic performance.The K‐OMS‐2nanorods synthesized by the solvent‐free method showed higher activity than K‐OMS‐2materials prepared by the reflux technique,and samples with cryptomelane were more active than those prepared by the conventional methods.The catalyst with the highest performance also exhibited good stability and allowed90%conversion of ethyl and butyl acetate to CO2at213and202°C,respectively.Significant differences in the catalyst performance were observed,clearly indicating that K‐OMS‐2nanorods prepared by the solvent‐free reaction were better catalysts for the selected VOC oxidations than the mixtures of manganese oxides traditionally obtained with conventional synthesis methods.The superior performance of the K‐OMS‐2catalysts might be related to the increased average oxidation state of the manganese in these structures.Significant correlations between the catalytic performance and the surface chemical properties were also identified,hig-hlighting the K‐OMS‐2properties associated with the enhanced catalytic performance of the materials.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Highly efficient UV-visible-infrared photothermocatalytic removal of ethyl acetate over a nanocomposite of CeO_(2) and Ce-doped manganese oxide

A unique nanocomposite of CeO_(2)nanoparticles and Ce-doped manganese oxide nanofibers having a crystalline cryptomelane-type octahedral molecular sieve(KMn_(8)O_(16)·nH_(2)O,abbreviated as OMS-2)structure(denoted CeO_(2)-CeOMS-2)was prepared by the reaction of Ce(NO_(3))3 and KMnO_(4)at 90°C.CeO_(2)-CeOMS-2 shows extremely high photothermocatalytic activity,very low selectivity for acetaldehyde(an unfavorable byproduct),and excellent durability for ethyl acetate removal under UV-visible-infrared(UV-vis-IR)irradiation.In striking contrast,pure CeO_(2),pure OMS-2,and TiO_(2)(P25)showed much lower photothermocatalytic activities and higher selectivities for acetaldehyde.The CO_(2)production rate within the first five minutes(r CO2)of reaction with CeO_(2)-CeOMS-2 was as high as 1102.5μmol g-1 min-1,which is 137,17,and 30-times higher than those of pure CeO_(2),pure OMS-2,and TiO_(2)(P25),respectively.CeO_(2)-CeOMS-2 also shows good photothermocatalytic activity under vis-IR(λ>420 or 560 nm)irradiation.Further,even under vis-IR(λ>830 nm)irradiation,efficient photothermocatalytic activity was achieved.In addition,the catalytic activity of CeO_(2)-CeOMS-2 is far superior to those of pure CeO_(2)and OMS-2,which is attributed to the fact that Ce doping significantly improves the lattice oxygen activity of OMS-2.The high photothermocatalytic activity of CeO_(2)-CeOMS-2 arises from the synergy between the photocatalytic effect of the CeO_(2)nanoparticles and light-driven thermocatalysis of the Ce-doped OMS-2.The novel photoactivation of Ce-doped OMS-2,which is unlike that of conventional photocatalysis on semiconductor photocatalysts,further promotes the catalytic activity because the surface oxygen activity of Ce-doped OMS-2 is promoted upon UV-vis-IR or vis-IR(λ>560 nm)irradiation.

Crystal Structure and Magnetic Property of 2-（Imidazo[1,2-α]pyri-din-2-yl）- 2-oxoacetic Acid and Its Perchlorate

We herein report two crystals based on 2-（imidazo[1,2-a]pyridin-2-yl）-2-oxoacetic acid rad- ical and its perchlorate, and investigate the relationship between magnetic properties and crystal stacking structures or supramolecular interactions. 2-（imidazo[1,2-a]pyridin-2-yl）- 2-oxoaeetic acid radical in two crystals mainly exist as diamagnetic dimer formed via short atomic contacts or supramolecular interactions （hydrogen bonds, anion-Tr or lone- pair-~r interactions）, leading to low magnetic susceptibilities. 2-（imidazo[1,2-a]pyridin-2-yl）- 2-oxoaeetic acid radical crystal exhibits quasi-one-dimensional columnar stacking chain and weak antiferromagnetism. However, its perchlorate crystal possesses one-dimensional double- stranded chain structure assembled through double hydrogen bonds and anion-To interactions, and reveals weak ferromagnetism.

Water-soluble UV curable urethane methyl acrylate coating：preparation and properties

Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

A Dynamic Study of Some Biological Active Compounds in the Sea-Buckthorn （Hippophae rhamnoides.L） Berries

In Mongolia, the sea buckthorn is a nontraditional fruit crop. It has been being planted since 2000 in the Botanical garden of Medicinal plants of Monos group, Mongolia. The purpose of this study was to determine how to change biological active compounds in the Sea-buckthorn berries that depending on harvesting season and to describe which harvesting period is efficient to use. In 2013-2014, fruit samples were prepared from our botanical garden such as： Chuiskaya, Maslichnaya, Vitaminnaya, Oranjivaya, Obilniya and Red cultivars on their chemical composition depended from harvesting season. The chemical compositions of fruit were investigated from 19th August to 20th January. We determined total oil, organic acid contents, 13-carotenoid, ascorbic acid, total phenolic content and polysaccharide. The chemical contents were analyzed with the Folin-Ciocalteau assay, colorimetric assay, volume metric analysis method and spectrophotometric method. During the harvesting period, the chemical compositions of samples such as total oil content and polysaccharide content were increased and the contents of organic acid, beta carotenoid and ascorbic acid were decreased. From our study, we concluded that fruit biological active compounds depend from harvest time and it could be used to choose production of seabuckthom product types.

Intake and Digestibility of Native and Exotic Grasses Fed Ad libitum to Djallonke Sheep in South Benin

Native （Andropogon gayanus, Panicum maximum and Pennisetum purpureum） and exotic grasses （Brachiaria ruzi：iensis, Panieum maximum cv. C1 and T58） consumed in tropical humid zone were evaluated by estimating their voluntary intake and in vivo digestibility. The measurements were performed with 4 male Djallonke sheep （28 kg LW） fed ad libitum in metabolic cages, during a 10-days in vivo trial, preceded by a 14-days accommodation period. Each grass was studied at 3 stages of development. The samples （distributed grasses, refusals and faeces） were analysed for organic matter （OM）, crude fibre （CF）, neutral detergent fibre （NDF）, acid detergent fibre （ADF）, acid detergent lignin （ADL） and crude protein （CP） contents. Voluntary digestible organic matter intake （VDOMI） and voluntary digestible crude protein intake （VDCPI） were calculated （in g kg ^-1 LW075） as synthetic parameters to compare the grasses. The chemical composition of the distributed forages varied significantly （P 〈 0.001） between species or cultivars and development stages. After 4-5 leaves per tiller stage, CP contents decreased in all species and lowest in native species. Andropogon gayanus was the most l ignified species at any stage of development. At the end of the rainy season, Pennisetum purpureum leaves and Brachiaria ruziziensis had the highest CP. For all the grasses, CP contents were higher （and CF contents lower） in the consumed material, compared to the offered forages, showing thereby the high selectivity by the sheep. Dry matter intake, OM and CP digestibility varied greatly （P 〈 0.001） between forages and development stages with high interactions between these factors （P 〈 0.001）. Voluntary digestible organic matter intake and VDCPI were the highest （P 〈 0.05） for native Panicum maximum and Pennisetum purpureum. There was a relationship between digestibility and intake parameters, and ADL content of the grasses seems to be an important factor determining at least digestibility.

Prediction of Polycyclic Aromatic Hydrocarbon Bioaccessibility to Earthworms in Spiked Soils by Composite Extraction with Hydroxypropyl-β-Cyclodextrin and Organic Acids

Traditional exhaustive extraction methods often overestimate the risk of polycyclic aromatic hydrocarbon(PAH) bioaccessibility to biota. Therefore, reliable assessment methods need to be established. In this study, a composite extraction with hydroxypropyl-β-cyclodextrin(HPCD) and three low-molecular-weight organic acids, oxalic acid(OA), malic acid(MA), and citric acid(CA), was used to predict the PAH bioaccessibility to earthworms, subjecting to two soils(red soil and yellow soil) spiked with selected PAHs,phenanthrene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene. For both soils,concentrations of PAHs by composite extraction using HPCD-OA(R^2= 0.89–0.92, slope = 1.89–2.03; n = 35), HPCD-MA(R^2=0.92–0.96, slope = 1.43–1.67; n = 35), and HPCD-CA(R^2= 0.92–0.96, slope = 1.26–1.56; n = 35) were significantly correlated with PAH accumulation in the Eisenia fetida earthworms. Moreover, the HPCD-CA-and HPCD-MA-extracted PAH concentrations were closer to the earthworm-accumulated PAH concentration than the extraction using just HPCD. The results indicated that the composite extraction could improve the prediction of PAH bioaccessibility, and therefore can serve as a reliable chemical method to predict PAH bioaccessibility to earthworms in contaminated soils.

Effect of esterification reaction of citric acid and ethylene glycol on the formation of multi-shelled cobalt oxide powders with superior electrochemical properties

In this study, for the first time, polymeric precursors have been used in the preparation of yolk-shell powders using a large-scale spray drying process. An esterification reaction between the carboxyl group of citric acid and the hydroxyl group of ethylene glycol inside the droplet produced organic polymers during the drying process of the droplet. During the spray drying process, the polymeric precursors enabled the formation of multi-shell cobalt oxide yolk- shell powders with superior electrochemical properties. The maximum number of shells of the particles in the yolk-shell powders post-treated at 300, 400, and 500 ℃ were six, five, and four, respectively. The initial discharge capacities of the cobalt oxide yolk-shell powders post-treated at 300, 400, and 500 ℃ were 1,188, 1,331, and 1,110 mAh·g^-1, and their initial charge capacities were 868, 1,005, and 798 mAh·g^-1, respectively. The discharge capacities of the powders post- treated at 300, 400, and 500 ℃ after 100 cycles were 815, 958, and 670 mAh·g^-1, respectively and their corresponding capacity retentions measured after the first cycles were 92%, 93%, and 82%, respectively. The pure phase Co3O4 yolk-shell powders post-treated at 400 ℃ had low charge transfer resistance and high lithium-ion diffusion rate.