In order to study the influence of nitrogen incorporated into amorphous carbon films, nitrogenated amorphous carbon films have been deposited by using surface wave plasma chemical vapor deposition under various ratios...In order to study the influence of nitrogen incorporated into amorphous carbon films, nitrogenated amorphous carbon films have been deposited by using surface wave plasma chemical vapor deposition under various ratios of N2/CH4 gas flow. Optical emission spectroscopy has been used to monitor plasma features near the deposition zone. After deposition, the samples are checked by Raman spectroscopy and x-ray photo spectroscopy (XPS). Optical emission intensities of CH and N atom in the plasma are found to be enhanced with the increase in the N2/CH4 gas flow ratio, and then reach their maximums when the N2/CH4 gas flow ratio is 5%. A contrary variation is found in Raman spectra of deposited films. The intensity ratio of the D band to the G band (Id/Ig) and the peak positions of the G and D bands all reach their minimums when the N2/CH4 gas flow ratio is 5%. These show that the structure of amorphous carbon films has been significantly modified by introduction of nitrogen.展开更多
Objective] The research aimed to study soil organic carbon and total ni-trogen distribution in oasis cotton farmland. [Method] With the oasis cotton field of Manas River Val ey in Tianshan Mountains as the research ar...Objective] The research aimed to study soil organic carbon and total ni-trogen distribution in oasis cotton farmland. [Method] With the oasis cotton field of Manas River Val ey in Tianshan Mountains as the research area and abandoned farmland as a control, the distribution characteristics of soil organic carbon and total nitrogen content in the cotton field of Manas River Val ey in the last 23 years were investigated by using geographic methods. [Result] Presenting vertical distribution, cotton soil organic carbon and total nitrogen content in Manas River Val ey de-creased with the increase of soil depth, and those in 0-30 cm soil layer was sig-nificantly higher than those in soil layer of below 30 cm, while organic carbon stor-age showed the trend of increase. Also in vertical distribution, soil organic carbon and total nitrogen decreased significantly with the increase of soil depth, and soil organic carbon content in abandoned farmland decreased month by month. Howev-er, cotton soil organic carbon storage firstly decreased and then increased in the oasis cotton field that in the early growth of cotton, soil organic carbon in the layers of 0-30 and 30-100 cm decreased to the lowest in the bloom stage, and then or-ganic carbon increased with the reproductive growth of cotton into the later stages. However, due to no input of plant litter in the abandoned farmland, the soil organic carbon storage decreased month by month. There were significantly differences be-tween oasis cotton field and abandoned farmland in organic carbon contents. [Con-clusion] The soil organic carbon content and total nitrogen content in oasis cotton field were significantly higher than those in the abandoned farmland. The soil organ-ic carbon storage increased in the layer of 0-30 cm, while there was no significant change of soil organic carbon and total nitrogen content in the layer of 30-100 cm, which was consistent with the previous study on the distribution characteristics of soil organic carbon and total nitrogen content profile.展开更多
Use Enteromorpha clathrate as a carbon and nitrogen precursor could obtain the N-doped porous carbon mate-rials by two-step pyrolysis.In this paper,the exogenous nitrogen(urea,melamine)and activating agents(KOH,ZnCl_(...Use Enteromorpha clathrate as a carbon and nitrogen precursor could obtain the N-doped porous carbon mate-rials by two-step pyrolysis.In this paper,the exogenous nitrogen(urea,melamine)and activating agents(KOH,ZnCl_(2))were employed for the production of higher-performance carbon materials from seaweed biomass.SEM,BET,FTIR,XRD,XPS,Raman and ultimate analyses were carried out to investigate the morpho-structural and elemental peculiarities of the carbonaceous materials.Moreover,cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and cyclic charge-discharge tests were carried out to examine the electrochemical properties of the samples.The results showed that electrochemical performance of the carbonaceous materials improved by adding the appropriate nitrogen sources.This improvement was observed under either condition,when the nitro-gen source and activating agent were melamine and ZnCl_(2) or urea and KOH,respectively.Specifically,under the condition with KOH as the activator,the nitrogen content of carbon material without exogenous nitrogen was initially 1.46%.After the addition of urea or melamine,the nitrogen content increased to 4.86%and 6.18%,respectively.Under the condition with ZnCl_(2) as the activator,and without exogenous nitrogen,the nitrogen con-tent of carbon materials was initially 3.75%.However,after adding urea or melamine,the nitrogen content increased to 12.11%and 14.76%,respectively.The carbonaceous materials(prepared from urea/KOH and mel-amine/ZnCl_(2))showed excellent gravimetric capacitances of 172 and 151.5 F/g at 1A/g.Moreover,at a current density of 5 A/g,their specific capacitance retention rate reached 78.3%and 82.6%respectively after 1000 cycles.展开更多
Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive ...Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive agricultural region in the Huang- Huai-Hai Plain of China. Prior to modelling, validation of the DNDC model against field data sets of SOC from Quzhou Experimental Station in the Huang-Huai-Hai Plain was conducted at the site scale. We compared the simulated results with the observed SOC in Huantai County during 1982-2011 under two different classification methods of simulation unit （the first method integrated soil type and land use of Huantai County to form the overlapped modeling units; the second selected the 11 administrative towns as the modeling units）, and achieved a high accuracy in the model simulation with the improvement of the model parameters. Regional SOC （0-20 cm） density and stocks for Huantai County in the years 2012-2031 were predicted under different scenarios of farming management. Compared with current management practices, optimized fertilization （20% decrease of mineral N）, crop straw incorporation （90%） and appropriate animal manure input （40 kg N ha-1 yr-1） could achieve the highest level of SOC density （56.8% higher than 2011） in the period of 2012-2031. The research highlighted the importance of crop straw incorporation, optimized N fertilization and integration of crop production with ani- mal husbandry on the farmland carbon sequestration for maintaining a high land productivity in the Huang-Huai-Hai Plain.展开更多
【目的】土壤微生物量碳氮和水溶性有机碳氮是土壤中最活跃的碳氮组分,是衡量土壤碳氮周转与养分有效性的重要指标。探讨秸秆配施氮肥、氮肥用量及基追比例对稻田土壤微生物量碳氮、水溶性有机碳氮、易氧化有机碳和速效氮的影响,明确秸...【目的】土壤微生物量碳氮和水溶性有机碳氮是土壤中最活跃的碳氮组分,是衡量土壤碳氮周转与养分有效性的重要指标。探讨秸秆配施氮肥、氮肥用量及基追比例对稻田土壤微生物量碳氮、水溶性有机碳氮、易氧化有机碳和速效氮的影响,明确秸秆还田条件下水稻生长季不同氮肥用量与基追比的土壤活性碳氮变化特征,为稻麦轮作区秸秆还田的氮肥管理提供理论依据。【方法】2012—2015年在湖北省荆门市田间试验中设置施氮量、秸秆配施氮肥和施氮时期3个大田试验。施氮量:不施氮(N0),推荐施氮(165 kg·hm^-2,N165),习惯施氮(195 kg·hm^-2,N195);秸秆配施氮肥:秸秆移除(CK),秸秆还田(移栽前将上季小麦秸秆全部还田,S),秸秆还田+习惯施氮量(SN),秸秆还田+推荐施氮量(SF),秸秆还田+推荐施氮量+腐解菌剂(SM);施氮时期:基施﹕拔节期﹕抽穗期氮肥施用比例为7﹕3﹕0(R1),5﹕3﹕2(R2),10﹕0﹕0(R3)。【结果】秸秆还田+习惯施氮量(SN)显著提高了水稻拔节期土壤微生物量碳(SMBC)含量,但是其成熟期水溶性有机碳含量(DOC)显著降低。秸秆还田+推荐施氮量(SF)显著提高了水稻拔节期土壤水溶性有机氮含量(DON)。腐解菌剂的施用显著降低了水稻成熟期DON含量,拔节期易氧化有机碳含量(ROC)也显著降低。秸秆还田下增加氮肥用量显著提高了水稻抽穗期和灌浆期土壤速效氮含量(AN);推荐施氮处理(165 kg N·hm^-2)的DON和AN含量显著升高;农民习惯施氮处理(195 kg N·hm^-2)降低了DON和AN含量;增加追施氮肥比例对土壤SMBC和DOC含量无明显影响,但提高了水稻拔节期SMBN和ROC含量。【结论】施氮量及其基追比是影响秸秆还田下稻田土壤活性碳氮含量的主要因素,合理配施氮肥能提高土壤微生物量碳、速效氮及水溶性有机氮等活性碳氮组分含量,增加追肥比例也能提高水稻生育期内土壤活性碳氮含量。展开更多
基金Natural Science Foundation of Anhui Province(No.03044702)National Natural Science Foundation of China(No.19835030)
文摘In order to study the influence of nitrogen incorporated into amorphous carbon films, nitrogenated amorphous carbon films have been deposited by using surface wave plasma chemical vapor deposition under various ratios of N2/CH4 gas flow. Optical emission spectroscopy has been used to monitor plasma features near the deposition zone. After deposition, the samples are checked by Raman spectroscopy and x-ray photo spectroscopy (XPS). Optical emission intensities of CH and N atom in the plasma are found to be enhanced with the increase in the N2/CH4 gas flow ratio, and then reach their maximums when the N2/CH4 gas flow ratio is 5%. A contrary variation is found in Raman spectra of deposited films. The intensity ratio of the D band to the G band (Id/Ig) and the peak positions of the G and D bands all reach their minimums when the N2/CH4 gas flow ratio is 5%. These show that the structure of amorphous carbon films has been significantly modified by introduction of nitrogen.
基金Supported by the National Natural Science Foundation of China(31360320)~~
文摘Objective] The research aimed to study soil organic carbon and total ni-trogen distribution in oasis cotton farmland. [Method] With the oasis cotton field of Manas River Val ey in Tianshan Mountains as the research area and abandoned farmland as a control, the distribution characteristics of soil organic carbon and total nitrogen content in the cotton field of Manas River Val ey in the last 23 years were investigated by using geographic methods. [Result] Presenting vertical distribution, cotton soil organic carbon and total nitrogen content in Manas River Val ey de-creased with the increase of soil depth, and those in 0-30 cm soil layer was sig-nificantly higher than those in soil layer of below 30 cm, while organic carbon stor-age showed the trend of increase. Also in vertical distribution, soil organic carbon and total nitrogen decreased significantly with the increase of soil depth, and soil organic carbon content in abandoned farmland decreased month by month. Howev-er, cotton soil organic carbon storage firstly decreased and then increased in the oasis cotton field that in the early growth of cotton, soil organic carbon in the layers of 0-30 and 30-100 cm decreased to the lowest in the bloom stage, and then or-ganic carbon increased with the reproductive growth of cotton into the later stages. However, due to no input of plant litter in the abandoned farmland, the soil organic carbon storage decreased month by month. There were significantly differences be-tween oasis cotton field and abandoned farmland in organic carbon contents. [Con-clusion] The soil organic carbon content and total nitrogen content in oasis cotton field were significantly higher than those in the abandoned farmland. The soil organ-ic carbon storage increased in the layer of 0-30 cm, while there was no significant change of soil organic carbon and total nitrogen content in the layer of 30-100 cm, which was consistent with the previous study on the distribution characteristics of soil organic carbon and total nitrogen content profile.
基金This work was supported by the Natural Science Foundation of Jiangsu Province(BK20200894)Key Research and Development Project of Jiangsu Province(BE2019009-4)Key Laboratory of Renewable Energy,Chinese Academy of Science(E029kf0201).
文摘Use Enteromorpha clathrate as a carbon and nitrogen precursor could obtain the N-doped porous carbon mate-rials by two-step pyrolysis.In this paper,the exogenous nitrogen(urea,melamine)and activating agents(KOH,ZnCl_(2))were employed for the production of higher-performance carbon materials from seaweed biomass.SEM,BET,FTIR,XRD,XPS,Raman and ultimate analyses were carried out to investigate the morpho-structural and elemental peculiarities of the carbonaceous materials.Moreover,cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and cyclic charge-discharge tests were carried out to examine the electrochemical properties of the samples.The results showed that electrochemical performance of the carbonaceous materials improved by adding the appropriate nitrogen sources.This improvement was observed under either condition,when the nitro-gen source and activating agent were melamine and ZnCl_(2) or urea and KOH,respectively.Specifically,under the condition with KOH as the activator,the nitrogen content of carbon material without exogenous nitrogen was initially 1.46%.After the addition of urea or melamine,the nitrogen content increased to 4.86%and 6.18%,respectively.Under the condition with ZnCl_(2) as the activator,and without exogenous nitrogen,the nitrogen con-tent of carbon materials was initially 3.75%.However,after adding urea or melamine,the nitrogen content increased to 12.11%and 14.76%,respectively.The carbonaceous materials(prepared from urea/KOH and mel-amine/ZnCl_(2))showed excellent gravimetric capacitances of 172 and 151.5 F/g at 1A/g.Moreover,at a current density of 5 A/g,their specific capacitance retention rate reached 78.3%and 82.6%respectively after 1000 cycles.
基金financially supported by the Non-profit Research Foundation for Agriculture, China (201103039)the National Natural Science Foundation of China (31261140367 and 31370527)
文摘Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive agricultural region in the Huang- Huai-Hai Plain of China. Prior to modelling, validation of the DNDC model against field data sets of SOC from Quzhou Experimental Station in the Huang-Huai-Hai Plain was conducted at the site scale. We compared the simulated results with the observed SOC in Huantai County during 1982-2011 under two different classification methods of simulation unit （the first method integrated soil type and land use of Huantai County to form the overlapped modeling units; the second selected the 11 administrative towns as the modeling units）, and achieved a high accuracy in the model simulation with the improvement of the model parameters. Regional SOC （0-20 cm） density and stocks for Huantai County in the years 2012-2031 were predicted under different scenarios of farming management. Compared with current management practices, optimized fertilization （20% decrease of mineral N）, crop straw incorporation （90%） and appropriate animal manure input （40 kg N ha-1 yr-1） could achieve the highest level of SOC density （56.8% higher than 2011） in the period of 2012-2031. The research highlighted the importance of crop straw incorporation, optimized N fertilization and integration of crop production with ani- mal husbandry on the farmland carbon sequestration for maintaining a high land productivity in the Huang-Huai-Hai Plain.
文摘【目的】土壤微生物量碳氮和水溶性有机碳氮是土壤中最活跃的碳氮组分,是衡量土壤碳氮周转与养分有效性的重要指标。探讨秸秆配施氮肥、氮肥用量及基追比例对稻田土壤微生物量碳氮、水溶性有机碳氮、易氧化有机碳和速效氮的影响,明确秸秆还田条件下水稻生长季不同氮肥用量与基追比的土壤活性碳氮变化特征,为稻麦轮作区秸秆还田的氮肥管理提供理论依据。【方法】2012—2015年在湖北省荆门市田间试验中设置施氮量、秸秆配施氮肥和施氮时期3个大田试验。施氮量:不施氮(N0),推荐施氮(165 kg·hm^-2,N165),习惯施氮(195 kg·hm^-2,N195);秸秆配施氮肥:秸秆移除(CK),秸秆还田(移栽前将上季小麦秸秆全部还田,S),秸秆还田+习惯施氮量(SN),秸秆还田+推荐施氮量(SF),秸秆还田+推荐施氮量+腐解菌剂(SM);施氮时期:基施﹕拔节期﹕抽穗期氮肥施用比例为7﹕3﹕0(R1),5﹕3﹕2(R2),10﹕0﹕0(R3)。【结果】秸秆还田+习惯施氮量(SN)显著提高了水稻拔节期土壤微生物量碳(SMBC)含量,但是其成熟期水溶性有机碳含量(DOC)显著降低。秸秆还田+推荐施氮量(SF)显著提高了水稻拔节期土壤水溶性有机氮含量(DON)。腐解菌剂的施用显著降低了水稻成熟期DON含量,拔节期易氧化有机碳含量(ROC)也显著降低。秸秆还田下增加氮肥用量显著提高了水稻抽穗期和灌浆期土壤速效氮含量(AN);推荐施氮处理(165 kg N·hm^-2)的DON和AN含量显著升高;农民习惯施氮处理(195 kg N·hm^-2)降低了DON和AN含量;增加追施氮肥比例对土壤SMBC和DOC含量无明显影响,但提高了水稻拔节期SMBN和ROC含量。【结论】施氮量及其基追比是影响秸秆还田下稻田土壤活性碳氮含量的主要因素,合理配施氮肥能提高土壤微生物量碳、速效氮及水溶性有机氮等活性碳氮组分含量,增加追肥比例也能提高水稻生育期内土壤活性碳氮含量。
