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1.
J Am Chem Soc ; 142(16): 7379-7385, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32259425

RESUMO

A series of rhodium complexes bearing sterically and electronically tunable cyclopentadienyl ligands, prepared by utilizing Co2(CO)8-mediated [2+2+1] cyclization as a key step, were synthesized. In the presence of 2.5 mol% of CpmRh4, unprecedented enantioselective [4+1] annulation reaction of benzamides and alkenes was achieved with a broad substrate scope under mild reaction conditions, providing a variety of isoindolinones with excellent regio- and enantioselectivity (up to 94% yield, 97:3 er). Preliminary mechanistic studies suggest that the reaction involves an oxidative Heck reaction and an intramolecular enantioselective alkene hydroamination reaction.

2.
J Org Chem ; 84(20): 13144-13149, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31342746

RESUMO

Palladium-catalyzed C-H diarylation of ferrocenes is described. In the presence of 10 mol % Pd(OAc)2, direct C-H diarylation reactions of commercially available ferrocenecarboxylic acid with aryl iodides proceeded smoothly to afford diarylated ferrocenes bearing a variety of functional groups in moderate to good yields. The carboxylic group could also act as a remote directing group to result in the third arylation on the other Cp ring of ferrocene.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(7): 2325-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30036023

RESUMO

Biochar could be got from crop straw which contain rich carbon under oxygen free or oxygen limited conditions at low temperature. The application of biochar into soil is beneficial to ease the pressure of handling straw, reduce pollution, reduce greenhouse gas emissions and improve soil quality. This study was carried out in a cornfield containing meadow brown soil at the lower reaches of Liao River which was treated with different amounts of biochar (0, 360, 1 800, 3 600 kg·ha-1) and fertilizer. We investigated the contents of soil available phosphorus (AP), organic P (OP) and total P (TP). We also investigated the enzyme activities of soil acid phosphatase (AcP), alkaline phosphatase (AlP) and phosphodiesterase (PD) via a fluorescence spectroscopy method by using a fluorescent conjugated polymer as the substrate. Soil AP contents increased drastically with the increasing application of biochar, whereas the OP and TP contents exhibited little change. The increase in AP contents was ascribed to the introduction of P into the soil via biochar. Soil AlP and PD activities increased with increasing biochar application. Soil AcP activity increased significantly after the application of the appropriate amount of biochar (1 800 kg·ha-1), whereas it was inhibited by the application of high levels of biochar (3 600 kg·ha-1), perhaps due to the intrinsic alkalinity of biochar. The effect of Biochar inputs on soil phosphorus element and phosphatase activity is the comprehensive embodiment of the soil physical properties, chemical properties, and microbial community structure and metabolic capacity. We should further study such item. The fluorescent microplate method used in this study has many advantages, such as accuracy, rapidness and simple to perform.

4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(5): 1478-82, 2016 May.
Artigo em Chinês | MEDLINE | ID: mdl-30001040

RESUMO

The direct absorption and utilization of low-molecular weight organic nitrogen (N) by soil microbial is a new subject in the research of microbial N nutrition. The study used gas chromatography-mass spectrometry to trace dual-labeled (13C, 15N) glycine from the soil solution and microorganisms. The results showed that glycine added to the soil was quickly taken up by soil microorganisms, with the half-life of glycine being 2.9 h. Withthe incubation of 4 h, the maximum amount of dual-labeled glycine in the microbial biomass was measured (equivalent to 10% of glycine added), indicating that added glycine was absorbed as intact molecular by soil microorganisms. The single labeled-Keto acid was detected in soil solution and in the microorganisms (decomposed production by double labeled glycine), but the content is extremely low, suggesting that added glycine mainly served as carbon (C) source for soil microbial life activities. This study demonstrated that compound specific stable dual labeled isotope analysis combined with chloroform fumigation technique was an effective method for detecting the low-molecular organic N utilized by soil microorganisms.


Assuntos
Microbiologia do Solo , Solo , Biomassa , Isótopos de Carbono , Cromatografia Gasosa-Espectrometria de Massas , Glicina , Marcação por Isótopo , Nitrogênio
5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(2): 455-9, 2014 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-24822420

RESUMO

The present work was aimed to study soil a-glucosidase and beta-glucosidase activities of and red soils based on fluorescence detection method combined with 96 microplates with TECAN Infinite 200 Multi-Mode Microplate Reader. We added biochar or straw (2.5 g air dry sample/50g air dry soil sample) into and red soils and the test was carried under fixed temperature and humidity condition (25 degrees C, 20% soil moisture content). The results showed that straw addition enhances soil alpha-glucosidase and beta-glucosidase activities, beta-glucosidase activity stimulated by rice straw treatment was higher than that of corn straw treatment, and activity still maintains strong after 40 days, accounting for increasing soil carbon transformation with straw inputting. Straw inputting increased soil nutrients contents and may promote microbial activity, which also lead to the increase oin enzyme Straw inputting increased soil nutrients contents and may promote microbial activity, which also lead to the increase oin enzyme activities. Different effects of straw kinds may be related to material source that needs further research. However, biochar inputting has little effect on soil alpha-glucosidase and beta-glucosidase activity. Biochar contains less available nutrients than straw and have degradation-resistant characteristics. Compared with the conventional spectrophotometric method, fluorescence microplate method is more sensitive to soil enzyme activities in suspension liquid, which can be used in a large number of samples. In brief, fluorescence microplate method is fast, accurate, and simple to determine soil enzymes activities.


Assuntos
Carvão Vegetal , Solo/química , alfa-Glucosidases/metabolismo , beta-Glucosidase/metabolismo , Carbono , Fluorescência , Oryza , Zea mays
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(6): 1519-25, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22870631

RESUMO

The degradability characteristics of film with 4 kinds of starch acetate coated and inhibitors amended urea were analyzed by FTIR, which was purposed to supply theoretical basis for applying starch acetate coated urea fertilizers in farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. The main peaks of the film degradation process were brought by the H--O, --OH, CO2, C==O, --CH2, --CH3, C--O, C--O--H and C--O--C vibrancy in asymmetry and symmetry. In brown soil, the trend of absorbing value of the most high peak was 0>15>30>60>90>120>150>310 d. The infrared spectra of 4 kinds of fertilizers were not different remarkably, and the film was comparatively slowly degraded before 15 d. But a majority of the film had been already degraded after 150 days. The main components of film materials were degraded fastest in 310 days. The speed of film degradation wasn't more impacted by different inhibitors. The characteristic of starch acetate film degradation may be monitored entirely and degradation speed difference of the film could be represented through infrared spectrum.

7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(3): 635-41, 2012 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-22582622

RESUMO

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. the main peaks of expressing film degradation process were brought by the -C-H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O, C=C flexing vibrancy in asymmetry and symmetry in 3 479-3 195, 2 993--2 873, 1 741-1 564, 1 461-925 and 850-650 cm(-1). The peak value changed from smooth to tip, and from width to narrow caused by chemical structural transform of film The infrared spectrum of 4 kinds of fertilizers was not different remarkably before 60 days, and the film was slowly degraded. But degradation of the film was expedited after 60 days, it was most quickened at 120 day, and the decomposition rate of film was decreased at 310 day. The substantiality change of film in main molecule structure of 4 kinds of fertilizers didn't happen in 310 days. The main component of film materials was degraded most slowly in brown soil. The speed of film degradation wasn't heavily impacted by different inhibitors. The characteristic of film degradation may be monitored entirely by infrared spectrum. The degradation dynamic, chemical structure change, degradation speed difference of the film could be represented through infrared spectrum.

8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(1): 204-8, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22497160

RESUMO

Analysis of leaf reflectance can provide a rich source of information about plant physiological process, surface properties of the leaf, as well as internal structure. In the present paper, the changes of reflectance spectra and spectral indices for transgenic barley and non-transgenic control variety based on measurements of single leaf were studied. The results showed that the ratio spectra that calculated by dividing one reflectance spectrum of transgenic barley by its' non-transgenic counterpart spectra were better to illustrate fine differences among spectra of leaves from different barley varieties. Ratio spectra varied between each pairs, but for most ratio spectrum indicated the reflectance differences between transgenic barley and non-transgenic counterpart were most obvious in the red spectrum around the chlorophyll peak and red edge (650-700 nm) and nearly identical in the green spectrum near 550 nm and within the near infrared region (beyond 750 nm). Across the entire calculated spectrum, the changes of reflectance within the region from 650 to 700 nm seem to be very sensitive to respond to possible unintended effects of genetic modification. Six published reflectance indices, the red edge (lambdaRE), the modified normalized difference vegetation index (mND), the structure-independent pigment index (SIPI), the ratio of reflectance in the red and green regions of the spectrum (R(Red)/R(Green)), the photochemical reflectance index (PRI) and the near-infrared reflectance at 800 nm (NIRR(800)) were used to make comparisons possible between species. The analyses of changes of these indices indicated that they were highly dependent on growth stages and barley varieties. Once indices described above have significant changes will mean that photosynthetic process, function and status of plants may be changed.


Assuntos
Hordeum/fisiologia , Fotossíntese , Plantas Geneticamente Modificadas/fisiologia , Clorofila/análise , Hordeum/genética , Folhas de Planta/fisiologia , Análise Espectral
9.
Ying Yong Sheng Tai Xue Bao ; 33(3): 664-670, 2022 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-35524517

RESUMO

Understanding the effects of different amounts of straw returning and nitrogen fertilizer application on soil CO2 emission from maize field can provide theoretical support for carbon sequestration and CO2 emission reduction and the implementation of black soil region conservation plan. Three rates of straw returning were set up in the semi-arid area of northwest Liaoning Province, China, i.e. 3000 (S1), 6000 (S2) and 9000 kg·hm-2(S3, full amount of straw returned to the field); crossed with three nitrogen fertilizer application rates in the sub-region, respectively, i.e. 105 (N1), 210 (N2, conventional nitrogen application rate) and 420 kg N·hm-2(N3). In addition, there was a control treatment (CK) without nitrogen fertilizer and straw returning. Soil samples were collected after 4 years field experiment with maize plantation. The influence of different treatments on maize field soil CO2 emission and the relationship between CO2 emission and soil dissolved organic carbon (DOC) and microbial biomass carbon (MBC) were investigated in an incubation experiment. The results showed that both of straw returning and nitrogen fertilizer application promoted soil CO2 emission in maize field, which were increased significantly with the increases of straw returning amount and nitrogen application amount. Nitrogen fertilizer application was the most important factor promoting soil CO2 emission in maize field. Straw returning combined with nitrogen fertilizer promoted soil CO2 emission by increasing microbial biomass and increasing DOC consumption. MBC and DOC stimulated soil CO2 emission significantly in maize field, and were mainly affected by their contents in the early stage of incubation. From the perspective of ensuring the fertilization of straw return to the field while reducing CO2 emissions, results from our experiment showed that 210 kg N·hm-2 conventional nitrogen application in combination with 6000 kg N·hm-2 straw returning (N2S2) was the most promising mode in the semi-arid area of northwest Liaoning Province.


Assuntos
Fertilizantes , Solo , Agricultura/métodos , Carbono/análise , Dióxido de Carbono , China , Nitrogênio/análise , Zea mays
10.
J Dent ; 117: 103925, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34929339

RESUMO

OBJECTIVES: The aim of this in-vitro study was to compare the virtual techniques for registering single-implant position to the physical gold standard using a universal-coordinate system. MATERIALS AND METHODS: Thirty dentate maxillary resin models with a dental implant inserted in the incisor region were prepared. On each model, a tooth-supported acrylic stent with a 1 cm x 1 cm x 1 cm cubic-corner (CC) was prepared. The Cartesian x,y,z-coordinate of the implant neck and apex were measured physically by a coordinate-measuring machine (CMM) with reference to this CC and served as the gold-standard. The resin models were scanned by a benchtop scanner (Group BS), cone-beam computed tomography (Group CBCT), and intraoral scanner (Group IOS). Stone casts, poured from open-tray polyether impression of the resin models, were scanned by the benchtop scanner (Group BS-cast). The implant neck and apex coordinates with reference to the CC were measured and the differences in the coordinates (∆x, ∆y, ∆z) and distance r from the gold standard were calculated. The data were analyzed by one-sample t-test and one-way ANOVA/Kruskal-Wallis test with the level of significance set at 0.05. RESULTS: The implant neck and apex positions of Group BS were statistically different from that of the CMM, r>0 (p<0.001). Group IOS showed a significant less ∆z and r at the implant neck than Group BS-cast (p = 0.006). No significant difference was found in the coordinates and distance at implant apex among Groups BS, CBCT, IOS and BS-cast. CONCLUSIONS: The physical measurements could be adopted as the gold standard in assessing the single-implant positions. The IOS was more accurate in registering the single-implant neck positions than scanning of the cast. CLINICAL SIGNIFICANCE: A universal-coordinate system defined by the cubic-corner allows comparing the virtual techniques in registering single-implant positions to the physical gold standard.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Materiais para Moldagem Odontológica , Prótese Dentária Fixada por Implante , Modelos Dentários
11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(1): 77-81, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21428061

RESUMO

After transgenic cotton residues incubated in soil 430 d, the contents and structural characteristics of soil humus fractions, fulvic acid, humic acid and humin were measured by potassium dichromate titrimetric method and Fourier transform infrared spectroscopy. The results showed that all soil humus fractions increased after the degradation of cotton residues, and the most relative increase was with humin and the least was with fulvic acid. Compared to their near-isogenic non-transgenic cottons, soil humus content for transgenic Bt cotton residue decreased, and that forr transgenic Bt+CpTI cotton Z41 was approximate, but that for transgenic Bt+CpTI cotton SGK321 increased. Infrared spectroscopy of fulvic acid, humic acid and humin showed the addition of cotton residue decreased the content of oxygenous groups, and increased the alkyl and amide groups. There were differences in the speed to form soil humus among three transgenic cottons. Transgenic Bt cotton was slower than its counterpart, transgenic Bt+CpTI cotton Z41 was approximate to its counterpart, but transgenic Bt+CpTI cotton SGK321 was faster than its counterpart.


Assuntos
Gossypium/química , Substâncias Húmicas/análise , Plantas Geneticamente Modificadas/química , Biodegradação Ambiental , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
12.
Ying Yong Sheng Tai Xue Bao ; 32(11): 3953-3960, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34898111

RESUMO

We examined the effects of nitrification inhibitors (NIs) on soil nitrification, maize yield and nitrogen use efficiency (NUE), aiming to screen out high efficiency stabilized ammonium chloride fertilizer in red soil. Nitrification inhibitors 2-chloro-6-trimethyl-pyridine (CP), 3, 4-dimethyl-pyrazolate phosphate (DMPP), and dicyandiamide (DCD) and their combinations were added into ammonium chloride (NH4Cl) to make six stabilized nitrogen fertilizers. With blank (CK) and NH4Cl (N) as the controls, we conducted a maize pot experiment with the same amount of nitrogen addition. The results showed that compared with the treatment of N, soil ammonium content in CP+DMPP and DMPP+DCD increased by 56%-62%, which was significantly higher than that in CP, DMPP, and DCD, while the apparent nitrification rate of red soil was significantly reduced by 33%-34%. All the six treatments with nitrification inhibitors and their combinations significantly improved biomass and nitrogen absorption efficiency of maize. Compared with the N treatment, the application of adding NIs alone was significantly higher than that of the treatments of NIs combinations, with an average of 1.3 times increase. DCD was the most efficient one in improving maize yield, nitrogen uptake, and nitrogen adsorption efficiency, which increased by 4.1, 6.3 and 4.4 times, respectively. Comprehensively, DCD performed the best in reducing cost and improving yield and nitrogen use efficiency in red soil.


Assuntos
Nitrificação , Solo , Fertilizantes/análise , Nitrogênio/análise , Zea mays
13.
Ying Yong Sheng Tai Xue Bao ; 32(12): 4419-4428, 2021 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-34951283

RESUMO

We carried out pot experiment to investigate nitrogen transformation characteristics, yield increasing effect, and apparent utilization rate of nitrogen fertilizer in loess soils by combining chemi-cal inhibitor and biostimulant humic acid to investigate the application effect and provide a theoretical basis for new type highly efficient and stable urea in loess soil. In this study, blank (CK) and urea (N) were set as controls, and humic acid alone (F), N-butyl thiophosphate-triamine (NBPT), 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP) and humic acid were respectively combined with three biochemical inhibitors to urea. The results showed that compared with N treatment, F, NBPT+F, DMPP+F, CP+F treatments significantly increased maize yield, chlorophyll content, leaf area index and nitrogen uptake, and had obvious effects on soil available nitrogen contents. The addition of humic acid increased chlorophyll content of maize leaves in all cases compared to the application of biochemical inhibitors alone. Compared with CP treatment, CP+F treatment could significantly increase nitrogen uptake, chlorophyll content, and nitrogen adsorption efficiency of maize. Addition of humic acid with NBPT increased nitrification inhibition rate by 10.7% compared with NBPT alone, but decreased yield, leaf area index, nitrogen uptake, nitrogen use efficiency. Compared with DMPP treatment, DMPP+F treatment significantly reduced maize yield, leaf area index, nitrogen uptake, nitrogen use efficiency and nitrification inhibition rate. Considering maize yield, plant N uptake, N fertilizer uptake rate and soil ammonium N and nitrate N contents, the addition of humic acid and CP is recommended for urea application in loess areas to enhance urea performance, yield, and fertilizer utilization.


Assuntos
Substâncias Húmicas , Ureia , Fertilizantes/análise , Nitrificação , Nitrogênio/análise , Solo
14.
Ying Yong Sheng Tai Xue Bao ; 32(2): 719-728, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33650382

RESUMO

How to determine the soil health status effectively is the basic issue to realize the agriculture green development. In the existing soil health assessment system, the importance of soil organi-sms in the maintenance of soil health is rarely considered. From the perspective of soil biological health, we discussed the connotation of soil health, and summarized the biological indicators of soil health, including soil microorganisms, soil enzyme activity, soil micro-food web and earthworm. Based on the above-mentioned indicators, the regulation approaches were elaborated from the aspects of crop and soil management practices. In addition, the future research on soil biological health was prospected. The main aim of this study is to enhance the understanding of scientists and decision makers on the maintenance of soil biological health, and to give full consideration of the important role of soil organisms in ecosystem services.


Assuntos
Oligoquetos , Solo , Agricultura , Animais , Ecossistema
15.
Ying Yong Sheng Tai Xue Bao ; 32(4): 1352-1360, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33899404

RESUMO

We studied the effects of urease/nitrification inhibitor combinations on urea hydrolysis and nitrification, aiming to screen out the effective inhibitor combinations for black soil and cinnamon soil in Northeast China. Urease inhibitor, N-butyl thiophosphate-triamine (NBPT), and its combination with nitrification inhibitor dicyandiamide (DCD), 3, 4-dimethylpyrazole phosphate (DMPP), 2-chloro-6 (trichloromethyl)-pyridine (CP), 2-amino-4-chloro-6-methylpyrimidine (AM) and 3-methylpyrazole (MP) were added to urea separately. Samples were collected 15 times in each of all the treatments during 125 days. We examined the changes of urea nitrogen, ammo-nium, nitrate, and nitrification inhibition rate in the two soils. Our results showed the hydrolysis of urea in black soil and cinnamon soil was about 7 d, and the addition of NBPT with or without diffe-rent nitrification inhibitors slowed down the hydrolysis to 21 d at least. Compared with the treatment with common urea, inhibitor addition significantly increased soil NH4+-N, decreased soil NO3--N, and maintained the high NH4+-N content in soil for a longer time. In black soil, application with nitrification inhibitor inhibited soil nitrification significantly and lasted for more than 125 d. DMPP and CP combined with NBPT increased the NH4+-N content in black soil by 1.6-1.8 times, while the nitrification inhibition rate was 47.9% and 24.1% at 125 d, respectively. In the cinnamon soil, the application of nitrification inhibitor could prolong the duration of ammonium oxidation from 80 d to 110 d. DCD and DMPP combined with NBPT increased the NH4+-N content in cinnamon soil by 2.1-3.4 times, while the nitrification inhibition rates at 125 d were 25.3% and 23.2%, respectively. Therefore, NBPT+DMPP combination with urea was recommended for utilization in black soil, followed by NBPT+CP. In cinnamon soil, NBPT+DCD combination with urea was recommended, followed by NBPT+DMPP.


Assuntos
Nitrificação , Solo , China , Cinnamomum zeylanicum/metabolismo , Fertilizantes/análise , Nitrogênio/análise , Ureia , Urease/metabolismo
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(7): 2011-3, 2010 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-20828021

RESUMO

Nitrification inhibitors exert inhibition function in soil nitrification process (NH4(+)-N to NO3(-)-N) and are widely applied in order to improve N fertilizer use efficiency. Before the new nitrification inhibitor is used, its effects on denitrification process must be investigated and denitrifying enzyme activity (DEA) is an effective indicator to show this process. In the present paper, a mass spectrometery (MS) method was taken to measure the denitrifying enzyme activity in the new nitrification inhibitor 3, 4-dimethylpyrazole phosphate (DMPP) incubation system. The results showed that the method measured the concentration of N2O in the incubation system accurately and the concentration measured by MS had marked correlation with that measured by gas chromatogram (GC) (MS(N2O) = -0.45 + 1.03GC(N2O, R2 = 0.995). At the same time, enrichment of 15 N2O and 15 N2 was measured to discriminate the nitrate reductase and N2O reductase. Differed with traditional method, the enzymatic inhibitor-acetylene was not appended. The results showed that DMPP had no influence on the denitrifying enzyme activity and indicated that the denitrification process was not influenced by DMPP.


Assuntos
Desnitrificação , Enzimas/metabolismo , Fertilizantes , Nitrogênio , Solo/química , Espectrometria de Massas
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(2): 323-6, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20384116

RESUMO

In the present paper, polylactic acid (PLA), poly (butylenes succinate) (PBS) and polycarbonate (PC) were selected as test coating materials, and the variations in their IR spectra under conditions of outdoor illumination and pot incubation were studied, aimed to approach the degradability of these coating materials under sunlight and in soil. The IR spectra showed that after 4 months under outdoor illumination and pot incubation with brown soil and black soil, all the test coating materials had definite variations in their structural configuration, being more obvious under pot incubation than under outdoor illumination, which suggested that the test materials were degradable, and the degradability was greater in soil than under sunlight. PC had the greatest degradability, followed by PLA, and PBS. The degradability of PLA and PC was greater in black soil than in brown soil, while that of PBS was reverse.

18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(7): 1918-21, 2010 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-20827999

RESUMO

The black soil, albic soil, brown soil and cinnamon soil in Northeast China were selected as research objects, and their mineral characteristics were evaluated with Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction spectroscopy (XRD), and scanning electron microscopy(SEM). The results showed that the mineral atlas of test soils were of montmorillonite type. Quartz was the main component of clay minerals in the four soils. Montmorillonite and high mountain stone had higher amounts in black soil and albic soil, and mica and high mountain stone were more in brown soil and cinnamon soil. Generally, the surface of mineral particles in black soil, brown soil and cinnamon soil seems to be of laminarization with significant un-uniformity, and compared with black soil, brown soil and cinnamon soil had more smooth surface. In contrast, the mineral particles in albic soil had distinct profile and smooth surface with some interstice. It was indicated that the components and characteristics of soil clay minerals could be analyzed by soil spectroscopy, and the related information to be obtained could be accurate and available.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(1): 179-83, 2010 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-20302109

RESUMO

After the potassium bichromate-strong sulfuric acid hot process, the ultraviolet spectrophotometer was used on the contrast with the traditional titrimetric method to analyze soil (51 years, 43 year, 32 year, 20 year vegetations restores in the Tenggeli sand) humus and the humus components content. At the same time, the infrared spectrum was used to discuss their structure change during restoring process. The result indicated that using the visible spectroscopy method for the determination of the humus and the humus component is feasible. The spectroscopy method determination of organic matter is better (coefficient of variation at most is 7.26%) than the traditional titrimetric method, as it is accurate, fast and simple, and favors large quantities. The result indicated that humus content presents increasing tendency along with restoring ages. Change is big in early restore time, and tends to be stable in the later period. Infrared spectrum shape is similar, but the characteristic peak intensity has obvious difference. Compared with the wind-drift sand, little molecule saccharides decrease and aryl-groups increase.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(5): 1210-3, 2010 May.
Artigo em Chinês | MEDLINE | ID: mdl-20672603

RESUMO

The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree. After 26 years' fertilization, the infrared spectrum shapes with different treatments are similar, but the characteristic peak intensity is obviously different, which reflects the effects of different fertilization treatments on the structure and amounts of soil humus or functional groups. Compared with no fertilization, little molecule saccharides decreased and aryl-groups increased under application of inorganic fertilizer or combined application of organic and chemical fertilizer. The effect was greater in Treatment NPK and M+NPK than in Treatment M1 N and M2 N. Organic and NPK fertilizer increased the development of soil and increased soil quality to a certain extent. Results showed that organic fertilization increased aromatization degree of soil humus and humus fractions distinctly. The authors could estimate soil humus evolvement of different fertilization with infrared spectroscopy.


Assuntos
Fertilizantes , Substâncias Húmicas/análise , Solo/química , Compostos Orgânicos , Análise Espectral
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