Plant volatiles induced by wounding play key roles in plant-insect and plant-plant interactions. To deeply understand the mechanism of their induction by wounding and their functions in interplant communications, four...Plant volatiles induced by wounding play key roles in plant-insect and plant-plant interactions. To deeply understand the mechanism of their induction by wounding and their functions in interplant communications, four diverse tree species: ashleaf maples ( Acer negundo L.), hankow willow (Salix matsudana Koidz.), Chinese white poplar ( Populus tomentosa Carr.) and poplar opera 8277 (P. simonii x P. pyramibalis cv.), were used as materials. The blends of volatiles collected after damage were detected with GCMS. Most of the induced compounds reach high concentrations in 5 h. They are acyclic monoterpenes, fatty acid derivatives, and aromatic compounds. To authors' knowledge, dimethyl adipate, diisobutyl succinate and benthothiazole have never been reported in previous herbivore insect-plant systems, After being damaged 2 h, green leaf volatiles were released in large amount. The repellents were detected in higher concentration after 24 h. The time of releasing is different within different species, but many kinds of volatiles widely existed in different trees. There were some difference among species. Health ashleaf maple released more terpenoids, but poplars and willow produced more aromatic compounds.展开更多
Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis of volatiles from unt...Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis of volatiles from untreated samples and three deodorized samples (under the optimal conditions) ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon (AC) adsorption, yeast extract (YE) masking and tea polyphenol (TP) treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained: AC adsorption (35 mg mL-1, 80℃, 40 rain), YE masking (7 mgmL l, 45 ℃, 30 min) and TP treatment (0.4mgmL-l, 40℃, 50min). AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine (TMA) formation in a P. un- dulate hydrolysate solution for a period of 72 h.展开更多
Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the l...Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the lubricating base-oils.For determination of aromatic content by the usual ASTM D3238 method,density,refractive index and molecular weight of the raffinate are required.In this work,a new generalized correlation is developed for de-termination the aromatic content by using only the measured viscosity of lubricating oil.With a mole fraction of aromatic compounds,the kinematic viscosity may be obtained at any temperature between 60-100°C along with their molecular weight and refractive index.展开更多
Aromatic compounds (ACs) in soil can induce competitive inhibition for soil NH3 oxidation, and nitrification inhibitors can be used to this end. A laboratory incubation experiment was performed with 12 nitroaromatic c...Aromatic compounds (ACs) in soil can induce competitive inhibition for soil NH3 oxidation, and nitrification inhibitors can be used to this end. A laboratory incubation experiment was performed with 12 nitroaromatic compounds (NACs), 15 amidoaromatic compounds (AACs) and 20 hydroxyaromatic compounds (HACs) to assess the inhibitory effects of ACs on soil nitrification. Based on these results, the critical and optimal concentrations of ACs were determined for better inhibitory effects. Most of the test ACs were able to inhibit soil nitrification; the effectiveness differed with soil type. Among the ACs, the NACs with m-nitryl, amino or hydroxyl and the AACs with a nitro group or a chlorine atom on aromatic ring or with a p-hydroxyl were more effective. 3-nitroaniline, 4-aminophenol and 3-nitrophenol showed the greatest potential as nitrification inhibitors. The critical concentration of these compounds in brown soil and cinnamon soil was found to be 0.5 mg kg-1 soil. Due to the toxicity, carcinogenicity and mutagenicity of ACs, further toxicological and ecotoxicological research is necessary before ACs are used as nitrification inhibitors in agricultural and horticultural practices.展开更多
Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross ...Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and O-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4P207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaOH, and the HA extracted by 0.1 mol L-1 NaOH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.展开更多
Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals...Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals were dominated by inertinitein seam 2 and by vitrinite in seam 9^(-2).Three maceral groups were selected as indicatorsof peat-forming environments.Two triangle diagrams were drawn based on the indicatorsto explicate the peat-forming environments of permian seam 2 and Carboniferousseam 9^(-2).The results indicate that the peat of carboniferous seam 9^(-2) formed dominantlyin wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swampsand open moor environments.展开更多
Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) has become a powerful tool for analyzing the detailed composition of petroleum samples. However, the correlation between the numerous peaks obtain...Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) has become a powerful tool for analyzing the detailed composition of petroleum samples. However, the correlation between the numerous peaks obtained by FT-ICR MS and bulk properties of petroleum samples is still a challenge. In this study, the internal standard method was applied for the quantitative analysis of four straight-run vacuum gas oils(VGO) by atmospheric pressure photoionization(APPI) FT-ICR MS. The heteroatom class distribution of these VGO samples turned to be different when the concentration changed. Linear relationship between the normalized abundance and the concentration of VGO samples was identified for the total aromatic compounds, aromatic hydrocarbons, S1 and N1 species. The differences of the response factors were also discussed. The sulfur contents of a series of crude oils were proved to be linear with the FT-ICR MS data calibrated by the response factor of S1 species. This study demonstrated the feasibility of the internal standard method in quantitative analysis with APPI FT-ICR MS, and the bulk properties of petroleum samples could be correlated directly with the FT-ICR MS data.展开更多
For the purpose of obtaining small molecular and oxygen-containing aromatic compounds, taking a toluene-extracted coal pitch as the research object, the oxidation of coal-pitch by ozone (03) in formic acid was studi...For the purpose of obtaining small molecular and oxygen-containing aromatic compounds, taking a toluene-extracted coal pitch as the research object, the oxidation of coal-pitch by ozone (03) in formic acid was studied. The coal-pitch sample and the oxidized pitch residue were characterized by elementary analysis and Fourier transform infrared spectroscopy (FTIR), while the small molecular products were analyzed by a gas chromatography-mass spectrometer (GC-MS). The results show that the highest oxygen content of oxidized coal pitch had been acquired at a reaction temperature of 50℃C, an 03 flow rate of 6300 mg/h and a reaction time of 4 h. Quite a lot of hydroxyls and carbonyls were introduced into the structure of the oxidized coal-pitch, while the small molecules produced mainly involve nonpolar aro- matic compounds, aromatic anhydride and quinone compounds. It is speculated that the mechanism is direct electrophilic oxidation in which the molecules of 03 directly attack the aromatic ring at its carbon atoms with high electron density, and then generate hydroxyl or carbonyl until the aromatic ring cracks. This study shows that 03 can make the fused aromatic ring of coal-pitch become oxidized and depoly- merized, and hence the ozonization of coal-pitch can be a potential method for obtaining oxygen- containing aromatic compounds.展开更多
Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD...Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD(T)), several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and (SbBi)2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers: square (D4h), roof-shaped (C2v-1), and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic (SbBi)2^2- species, there are also three stable isomers: rhombus (D2h), roof-shaped (C1), and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts (NICS) values of roof-shaped isomers for Sb4^2-, Bi4^2-, and (SbBi)2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.展开更多
This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming u...This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming units. This article also explores the technical measures for maximizing the target products delivered by the gasoline-type and aromatic-type CCR units with respect to the selection of catalysts, the optimization of feedstock and the optimized operating regime.展开更多
Special attention should be paid to the preparation of "special chemicals" from coal and the conversion of them. In this thesis, the alkylation and acylation of some polycyclic aromatics, naphthalene, acenap...Special attention should be paid to the preparation of "special chemicals" from coal and the conversion of them. In this thesis, the alkylation and acylation of some polycyclic aromatics, naphthalene, acenaphthene and anthracene, catalyzed by Lewis acid AlCl 3 in carbon disulfide (CS 2) and nitrobenzene (PhNO 2), were investigated. The results show that some important organic intermediates and monomers can be selectively synthesized by controlling the reaction conditions.展开更多
Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic com...Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic compounds, whereas the following processes are evaluated: (l) partial hydrogenation of benzene to cyclohexene; (2) hydrogenation of aniline; (3) hydrogenation of diphenylamine; (4) preparation of aniline from nitrobenzene; (5) hydrogenation of chloronitrobenzenes; (6) hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture. Processes (1) and (6) are typically carried out in the water-oil system. Generally, this type of system allows reaching a higher selectivity to desired products. In the case of hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture, the water phase extracts a water soluble catalyst; which is recycled and used for condensation of aniline and nitrobenzene. Problems of reaction kinetics, as well as catalysts deactivation are here discussed.展开更多
A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on ...A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid soil.The changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical analyses.By the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage sludge.The non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly higher.After 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage sludge.However,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ones.Thus,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil OM.The pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 months.In conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.展开更多
Aromatic hydrocarbons are generally main distillation of crude oil and organic extract of source rocks. Bicyclic and tricyclic aromatic hydrocarbons can be purified by two-step method of chromatography on alumina. Car...Aromatic hydrocarbons are generally main distillation of crude oil and organic extract of source rocks. Bicyclic and tricyclic aromatic hydrocarbons can be purified by two-step method of chromatography on alumina. Carbon isotopic composition of in- dividual aromatic hydrocarbons is affected not only by thermal maturity, but also by organic matter input, depositional envi- ronment, and hydrocarbon generation process based on the GC-IRMS analysis of Upper Ordovician, Lower Ordovician, and Cambrian source rocks in different areas in the Tarim Basin, western China. The subgroups of aromatic hydrocarbons as well as individual aromatic compound, such as 1-MP, 9-MP, and 2,6-DMP from Cambrian-Lower Ordovician section show more depleted 13C distribution. The δ13C value difference between Cambrian-Lower Ordovician section and Upper Ordovician source rocks is up to 16.1%o for subgroups and 14%o for individual compounds. It can provide strong evidence for oil source correlation by combing the δ13C value and biomarker distribution of different oil and source rocks from different strata in the Tarim Basin. Most oils from Tazhong area have geochemical characteristics such as more negative δI3Cg_Mp value, poor gam macerane, and abundant homohopanes, which indicate that Upper Ordovician source rock is the main source rock. In contrast, oils from Tadong area and some oils from Tazhong area have geochemical characteristics such as high 613C9-MP, value, abun dant gammacerane, and poor homohopanes, which suggest that the major contributor is Cambrian-Lower Ordovician source rock.展开更多
This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environme...This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.展开更多
Nanoscale noble metals can exhibit excellent photochemical and photophysical properties, due to surface plasmon resonance(SPR) from specifically collective electronic excitations on these metal surfaces. The SPR effec...Nanoscale noble metals can exhibit excellent photochemical and photophysical properties, due to surface plasmon resonance(SPR) from specifically collective electronic excitations on these metal surfaces. The SPR effect triggers many new surface processes, including radiation and radiationless relaxations. As for the radiation process, the SPR effect causes the significant focus of light and enormous enhancement of the local surface optical electric field, as observed in surface-enhanced Raman spectroscopy(SERS) with very high detection sensitivity(to the single-molecule level). SERS is used to identify surface species and characterize molecular structures and chemical reactions. For the radiationless process, the SPR effect can generate hot carriers, such as hot electrons and hot holes, which can induce and enhance surface chemical reactions. Here, we review our recent work and related literature on surface catalytic-coupling reactions of aromatic amines and aromatic nitro compounds on nanostructured noble metal surfaces. Such reactions are a type of novel surface plasmon-enhanced chemical reaction. They could be simultaneously characterized by SERS when the SERS signals are assigned. By combining the density functional theory(DFT) calculations and SERS experimental spectra, our results indicate the possible pathways of the surface plasmonenhanced photochemical reactions on nanostructures of noble metals. To construct a stable and sustainable system in the conversion process of the light energy to the chemical energy on nanoscale metal surfaces, it is necessary to simultaneously consider the hot electrons and the hot holes as a whole chemical reaction system.展开更多
Tetrathiafulvalene (TTF) is a kind of fused ring aromatic compound containing four sulfur atoms in one molecule, which is well known as a charge transport material. In order to calculate the charge mobility of this se...Tetrathiafulvalene (TTF) is a kind of fused ring aromatic compound containing four sulfur atoms in one molecule, which is well known as a charge transport material. In order to calculate the charge mobility of this semiconductor, Marcus electron transfer theory and the embedded model, which can give small intramolecular reorganization energies, were employed. The calculated results were in good agreement with the experimental values, so the above computing model is appropriate to assess the electrical property of TTF. On this basis, we predicted the charge mobility of 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene (BDH-TTP) crystals, for which the molecular structure is similar to TTF. The calculated results indicated that BDH-TTP is a p-type material, which has a better performance than TTF in hole transfer due to larger hole coupling and the smaller hole injection barrier. In addition, the direct coupling (DC) and the site energy correction (SEC) methods were used to calculate the charge transfer integrals. Although the results were slightly different, the qualitative trends were the same. Furthermore we took into account the anisotropic transfer properties of TTF and BDH-TTF, since obviously the mobilities along one dimension are larger than those along three dimensions. Finally, natural bond orbital analysis was used to study the interactions in all of the dimers.展开更多
文摘Plant volatiles induced by wounding play key roles in plant-insect and plant-plant interactions. To deeply understand the mechanism of their induction by wounding and their functions in interplant communications, four diverse tree species: ashleaf maples ( Acer negundo L.), hankow willow (Salix matsudana Koidz.), Chinese white poplar ( Populus tomentosa Carr.) and poplar opera 8277 (P. simonii x P. pyramibalis cv.), were used as materials. The blends of volatiles collected after damage were detected with GCMS. Most of the induced compounds reach high concentrations in 5 h. They are acyclic monoterpenes, fatty acid derivatives, and aromatic compounds. To authors' knowledge, dimethyl adipate, diisobutyl succinate and benthothiazole have never been reported in previous herbivore insect-plant systems, After being damaged 2 h, green leaf volatiles were released in large amount. The repellents were detected in higher concentration after 24 h. The time of releasing is different within different species, but many kinds of volatiles widely existed in different trees. There were some difference among species. Health ashleaf maple released more terpenoids, but poplars and willow produced more aromatic compounds.
基金supported by the Public Science and Technology Research Funds Projects of Ocean (No.201305018)the National Key Technology Research and Development Program for the 12th Five-Year Plan (No.2012BAD33B10)+3 种基金the National Natural Science Foundation of Guangdong, China (Nos. 2014A 030310351 and 2014A030310338)the Innovative Development of Marine Economy Regional Demonstration Projects of Guangdong (Nos.SZHY2012-B01-004 and GD2013-B03-001)the Science and Technology Planning Project of Guangdong Province, China (Nos.2013B 090800002 and 2015B090904003)the National Science Foundation for Young Scientists of China (No.31101271)
文摘Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis of volatiles from untreated samples and three deodorized samples (under the optimal conditions) ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon (AC) adsorption, yeast extract (YE) masking and tea polyphenol (TP) treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained: AC adsorption (35 mg mL-1, 80℃, 40 rain), YE masking (7 mgmL l, 45 ℃, 30 min) and TP treatment (0.4mgmL-l, 40℃, 50min). AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine (TMA) formation in a P. un- dulate hydrolysate solution for a period of 72 h.
文摘Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the lubricating base-oils.For determination of aromatic content by the usual ASTM D3238 method,density,refractive index and molecular weight of the raffinate are required.In this work,a new generalized correlation is developed for de-termination the aromatic content by using only the measured viscosity of lubricating oil.With a mole fraction of aromatic compounds,the kinematic viscosity may be obtained at any temperature between 60-100°C along with their molecular weight and refractive index.
基金Supported by the National Basic Research Program (973 Program) of China (No.2007CB109307)the National Science & Technology Pillar Program (No.2006BAD10B01)
文摘Aromatic compounds (ACs) in soil can induce competitive inhibition for soil NH3 oxidation, and nitrification inhibitors can be used to this end. A laboratory incubation experiment was performed with 12 nitroaromatic compounds (NACs), 15 amidoaromatic compounds (AACs) and 20 hydroxyaromatic compounds (HACs) to assess the inhibitory effects of ACs on soil nitrification. Based on these results, the critical and optimal concentrations of ACs were determined for better inhibitory effects. Most of the test ACs were able to inhibit soil nitrification; the effectiveness differed with soil type. Among the ACs, the NACs with m-nitryl, amino or hydroxyl and the AACs with a nitro group or a chlorine atom on aromatic ring or with a p-hydroxyl were more effective. 3-nitroaniline, 4-aminophenol and 3-nitrophenol showed the greatest potential as nitrification inhibitors. The critical concentration of these compounds in brown soil and cinnamon soil was found to be 0.5 mg kg-1 soil. Due to the toxicity, carcinogenicity and mutagenicity of ACs, further toxicological and ecotoxicological research is necessary before ACs are used as nitrification inhibitors in agricultural and horticultural practices.
基金Project (No. 39790100) supported by the National Natural Science Foundation of China.
文摘Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and O-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4P207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaOH, and the HA extracted by 0.1 mol L-1 NaOH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.
基金Supported by the National Natural Science Foundation of China(40773040)the National Basic Research Program of China (2003CB214607)
文摘Maceral composition and aromatic compounds were determined on columnsamples to study the peat-forming environments of Permian coal seam 2 and Carboniferouscoal seam 9^(-2) from the Xingtai coalfield,China.The macerals were dominated by inertinitein seam 2 and by vitrinite in seam 9^(-2).Three maceral groups were selected as indicatorsof peat-forming environments.Two triangle diagrams were drawn based on the indicatorsto explicate the peat-forming environments of permian seam 2 and Carboniferousseam 9^(-2).The results indicate that the peat of carboniferous seam 9^(-2) formed dominantlyin wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swampsand open moor environments.
基金supported by the Major State Basic Research Development Program of China(973 Program,No.2012CB224801)
文摘Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) has become a powerful tool for analyzing the detailed composition of petroleum samples. However, the correlation between the numerous peaks obtained by FT-ICR MS and bulk properties of petroleum samples is still a challenge. In this study, the internal standard method was applied for the quantitative analysis of four straight-run vacuum gas oils(VGO) by atmospheric pressure photoionization(APPI) FT-ICR MS. The heteroatom class distribution of these VGO samples turned to be different when the concentration changed. Linear relationship between the normalized abundance and the concentration of VGO samples was identified for the total aromatic compounds, aromatic hydrocarbons, S1 and N1 species. The differences of the response factors were also discussed. The sulfur contents of a series of crude oils were proved to be linear with the FT-ICR MS data calibrated by the response factor of S1 species. This study demonstrated the feasibility of the internal standard method in quantitative analysis with APPI FT-ICR MS, and the bulk properties of petroleum samples could be correlated directly with the FT-ICR MS data.
基金financially supported by the Key Project of Science and Technology of Universities of Henan Province (No.14A530003)the Key Project of Science and Technology of Henan Province (No.152102310090)
文摘For the purpose of obtaining small molecular and oxygen-containing aromatic compounds, taking a toluene-extracted coal pitch as the research object, the oxidation of coal-pitch by ozone (03) in formic acid was studied. The coal-pitch sample and the oxidized pitch residue were characterized by elementary analysis and Fourier transform infrared spectroscopy (FTIR), while the small molecular products were analyzed by a gas chromatography-mass spectrometer (GC-MS). The results show that the highest oxygen content of oxidized coal pitch had been acquired at a reaction temperature of 50℃C, an 03 flow rate of 6300 mg/h and a reaction time of 4 h. Quite a lot of hydroxyls and carbonyls were introduced into the structure of the oxidized coal-pitch, while the small molecules produced mainly involve nonpolar aro- matic compounds, aromatic anhydride and quinone compounds. It is speculated that the mechanism is direct electrophilic oxidation in which the molecules of 03 directly attack the aromatic ring at its carbon atoms with high electron density, and then generate hydroxyl or carbonyl until the aromatic ring cracks. This study shows that 03 can make the fused aromatic ring of coal-pitch become oxidized and depoly- merized, and hence the ozonization of coal-pitch can be a potential method for obtaining oxygen- containing aromatic compounds.
文摘Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory (B3LYP) and two post- Hartree-Fock approaches (MP2, CCSD(T)), several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and (SbBi)2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers: square (D4h), roof-shaped (C2v-1), and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic (SbBi)2^2- species, there are also three stable isomers: rhombus (D2h), roof-shaped (C1), and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts (NICS) values of roof-shaped isomers for Sb4^2-, Bi4^2-, and (SbBi)2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.
文摘This article based on the target products manufactured by the gasoline-type and aromatic-type continuous catalytic reforming (CCR) units makes an assessment on the technical indicators of these cata- lytic reforming units. This article also explores the technical measures for maximizing the target products delivered by the gasoline-type and aromatic-type CCR units with respect to the selection of catalysts, the optimization of feedstock and the optimized operating regime.
基金Jiangsu U niversity Foundation for Qualified Personal(6810 0 0 0 0 19)
文摘Special attention should be paid to the preparation of "special chemicals" from coal and the conversion of them. In this thesis, the alkylation and acylation of some polycyclic aromatics, naphthalene, acenaphthene and anthracene, catalyzed by Lewis acid AlCl 3 in carbon disulfide (CS 2) and nitrobenzene (PhNO 2), were investigated. The results show that some important organic intermediates and monomers can be selectively synthesized by controlling the reaction conditions.
文摘Peculiarities of a liquid phase hydrogenation, namely lower diffusivity of components influencing the reaction rate and deactivation of catalysts by leaching, are discussed. A focus is on hydrogenation of aromatic compounds, whereas the following processes are evaluated: (l) partial hydrogenation of benzene to cyclohexene; (2) hydrogenation of aniline; (3) hydrogenation of diphenylamine; (4) preparation of aniline from nitrobenzene; (5) hydrogenation of chloronitrobenzenes; (6) hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture. Processes (1) and (6) are typically carried out in the water-oil system. Generally, this type of system allows reaching a higher selectivity to desired products. In the case of hydrogenation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine mixture, the water phase extracts a water soluble catalyst; which is recycled and used for condensation of aniline and nitrobenzene. Problems of reaction kinetics, as well as catalysts deactivation are here discussed.
基金Supported by the Spanish Ministry of Science and Innovation (No. CTM 2007-60061)the CSIC-I3P fellowship from the Council of Scientific Research (CSIC) of Spain
文摘A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid soil.The changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical analyses.By the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage sludge.The non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly higher.After 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage sludge.However,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ones.Thus,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil OM.The pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 months.In conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.
基金supported by National Natural Science Foundation of China(Grant No.40973041)College Fund for the Doctoral Project(Grant No.20104220110001)Natural Science Foundation of Hubei Province(Grant No.2009CDB205)
文摘Aromatic hydrocarbons are generally main distillation of crude oil and organic extract of source rocks. Bicyclic and tricyclic aromatic hydrocarbons can be purified by two-step method of chromatography on alumina. Carbon isotopic composition of in- dividual aromatic hydrocarbons is affected not only by thermal maturity, but also by organic matter input, depositional envi- ronment, and hydrocarbon generation process based on the GC-IRMS analysis of Upper Ordovician, Lower Ordovician, and Cambrian source rocks in different areas in the Tarim Basin, western China. The subgroups of aromatic hydrocarbons as well as individual aromatic compound, such as 1-MP, 9-MP, and 2,6-DMP from Cambrian-Lower Ordovician section show more depleted 13C distribution. The δ13C value difference between Cambrian-Lower Ordovician section and Upper Ordovician source rocks is up to 16.1%o for subgroups and 14%o for individual compounds. It can provide strong evidence for oil source correlation by combing the δ13C value and biomarker distribution of different oil and source rocks from different strata in the Tarim Basin. Most oils from Tazhong area have geochemical characteristics such as more negative δI3Cg_Mp value, poor gam macerane, and abundant homohopanes, which indicate that Upper Ordovician source rock is the main source rock. In contrast, oils from Tadong area and some oils from Tazhong area have geochemical characteristics such as high 613C9-MP, value, abun dant gammacerane, and poor homohopanes, which suggest that the major contributor is Cambrian-Lower Ordovician source rock.
文摘This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.
基金financially supported by the National Natural Science Foundation of China(21321062,21373172)
文摘Nanoscale noble metals can exhibit excellent photochemical and photophysical properties, due to surface plasmon resonance(SPR) from specifically collective electronic excitations on these metal surfaces. The SPR effect triggers many new surface processes, including radiation and radiationless relaxations. As for the radiation process, the SPR effect causes the significant focus of light and enormous enhancement of the local surface optical electric field, as observed in surface-enhanced Raman spectroscopy(SERS) with very high detection sensitivity(to the single-molecule level). SERS is used to identify surface species and characterize molecular structures and chemical reactions. For the radiationless process, the SPR effect can generate hot carriers, such as hot electrons and hot holes, which can induce and enhance surface chemical reactions. Here, we review our recent work and related literature on surface catalytic-coupling reactions of aromatic amines and aromatic nitro compounds on nanostructured noble metal surfaces. Such reactions are a type of novel surface plasmon-enhanced chemical reaction. They could be simultaneously characterized by SERS when the SERS signals are assigned. By combining the density functional theory(DFT) calculations and SERS experimental spectra, our results indicate the possible pathways of the surface plasmonenhanced photochemical reactions on nanostructures of noble metals. To construct a stable and sustainable system in the conversion process of the light energy to the chemical energy on nanoscale metal surfaces, it is necessary to simultaneously consider the hot electrons and the hot holes as a whole chemical reaction system.
基金supported by the Key Laboratory for New Molecule Material DesignFunction of Tianshui Normal University+3 种基金the Scientific Research Projects of Middle-agedYoung Researchers in Tianshui Normal University (TSA1116)the National Natural Science Foundation of China (21071110)the Fund of the Educational Commission of Gansu Province (1108-03)
文摘Tetrathiafulvalene (TTF) is a kind of fused ring aromatic compound containing four sulfur atoms in one molecule, which is well known as a charge transport material. In order to calculate the charge mobility of this semiconductor, Marcus electron transfer theory and the embedded model, which can give small intramolecular reorganization energies, were employed. The calculated results were in good agreement with the experimental values, so the above computing model is appropriate to assess the electrical property of TTF. On this basis, we predicted the charge mobility of 2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene (BDH-TTP) crystals, for which the molecular structure is similar to TTF. The calculated results indicated that BDH-TTP is a p-type material, which has a better performance than TTF in hole transfer due to larger hole coupling and the smaller hole injection barrier. In addition, the direct coupling (DC) and the site energy correction (SEC) methods were used to calculate the charge transfer integrals. Although the results were slightly different, the qualitative trends were the same. Furthermore we took into account the anisotropic transfer properties of TTF and BDH-TTF, since obviously the mobilities along one dimension are larger than those along three dimensions. Finally, natural bond orbital analysis was used to study the interactions in all of the dimers.