针对湖北省桑园立地条件差,肥料使用不科学,造成土壤营养元素缺乏和不平衡等问题,开展测土配方优化施肥试验示范.通过对郧西县六郎乡罗坡垭村桑园土壤肥力的分析发现,土壤养分含量中等,表现为极缺碱解氮,进而制订了不施肥、习惯施肥(全...针对湖北省桑园立地条件差,肥料使用不科学,造成土壤营养元素缺乏和不平衡等问题,开展测土配方优化施肥试验示范.通过对郧西县六郎乡罗坡垭村桑园土壤肥力的分析发现,土壤养分含量中等,表现为极缺碱解氮,进而制订了不施肥、习惯施肥(全年尿素750kg/hm^2)和增量施肥(全年尿素1500kg/hm^2)3个施肥处理方案.结果表明,增量施肥明显提高了桑树(Morus alba L.)的抽枝能力,促进了桑树枝条的伸长生长,单株产叶量、公顷产叶量及桑叶品质明显提高,桑树的抗旱能力得到改善.得出了气候条件(降雨量)是影响桑树养分吸收量及桑园养分利用率的重要因子结论.展开更多
We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the r...We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the reference electrode under an alternative sweep voltage.It can increase the total current afforded by the reference electrode,and eliminate the interference deriving from the finite plasma sheath resistance of the reference electrode.The results in both theory and experiment lead to the conclusion that the usage of displaced current is valid and more efficient with a floating probe method.This method is applied in some harsh plasma environments when the grounded chamber wall can easily be contaminated by the dielectric.展开更多
A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial...A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial symmetries while with a finite radial wavenumber.The complete 3D spectra features of this structure have been identified to have the characteristics expected for zonal flows.展开更多
文摘针对湖北省桑园立地条件差,肥料使用不科学,造成土壤营养元素缺乏和不平衡等问题,开展测土配方优化施肥试验示范.通过对郧西县六郎乡罗坡垭村桑园土壤肥力的分析发现,土壤养分含量中等,表现为极缺碱解氮,进而制订了不施肥、习惯施肥(全年尿素750kg/hm^2)和增量施肥(全年尿素1500kg/hm^2)3个施肥处理方案.结果表明,增量施肥明显提高了桑树(Morus alba L.)的抽枝能力,促进了桑树枝条的伸长生长,单株产叶量、公顷产叶量及桑叶品质明显提高,桑树的抗旱能力得到改善.得出了气候条件(降雨量)是影响桑树养分吸收量及桑园养分利用率的重要因子结论.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10675121,10705028 and 10835009the ITER Domestic Program of China under Grant Nos 2009GB107000 and 2010GB107000.
文摘We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the reference electrode under an alternative sweep voltage.It can increase the total current afforded by the reference electrode,and eliminate the interference deriving from the finite plasma sheath resistance of the reference electrode.The results in both theory and experiment lead to the conclusion that the usage of displaced current is valid and more efficient with a floating probe method.This method is applied in some harsh plasma environments when the grounded chamber wall can easily be contaminated by the dielectric.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10875124 and 10605025the National Basic Research Program of China under Grant No 2008CB717800+2 种基金Research Fund for the Doctoral Program of Higher Education of China under Grant No 20060358059the ITER domestic program of China under Grant No 2010GB107000the Knowledge Innovation Program of Chinese Academy of Sciences under Grant No kjcx-yw-n28.
文摘A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial symmetries while with a finite radial wavenumber.The complete 3D spectra features of this structure have been identified to have the characteristics expected for zonal flows.
