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玉米秸秆生物炭对石灰性农田土壤氮转化菌数量和功能的影响
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作者 李文静 王朝旭 《应用化工》 CAS CSCD 北大核心 2019年第S02期129-135,139,共8页
为探明玉米秸秆生物炭对黄土高原石灰性农田土壤氮转化菌数量和功能的影响,在施氮肥条件下设置0、0.5%、1%和2%(质量比)4个生物炭添加量(记为N、NB_(0.005)、NB _(0.01)和NB _(0.02)),同时设置不施氮肥且不加生物炭的处理(CK),开展为期5... 为探明玉米秸秆生物炭对黄土高原石灰性农田土壤氮转化菌数量和功能的影响,在施氮肥条件下设置0、0.5%、1%和2%(质量比)4个生物炭添加量(记为N、NB_(0.005)、NB _(0.01)和NB _(0.02)),同时设置不施氮肥且不加生物炭的处理(CK),开展为期50 d的室内静态土壤培养实验,探究土壤好氧自生固氮菌、氨化细菌、氨氧化细菌和亚硝酸盐氧化细菌数量,以及氨化速率、氨氧化速率和亚硝酸盐氧化速率的动态变化。同时分析整个培养过程中各处理总有机碳(total organic carbon,TOC)和总氮(total nitrogen,TN)含量的动态变化。结果表明,在整个培养过程中,同一采样时间点,与CK和N处理相比,生物炭配施氮肥处理显著提高了土壤氮转化菌数量和氮转化速率,促进程度整体表现为:NB _(0.02)>NB _(0.01)>NB_(0.005)。另外,玉米秸秆生物炭可以作为外源有机碳,补充石灰性农田土壤的碳库,促进土壤TOC积累,且玉米秸秆生物炭的添加有助于提高土壤TN含量。相关性分析表明,石灰性农田土壤氮转化过程中,氮转化菌数量和相应的氮转化速率之间存在显著正相关关系,宏观的土壤氮转化速率是微观的土壤氮转化菌数量的直接反映。该研究有助于深入理解生物炭在黄土高原石灰性农田土壤氮转化过程中的作用,对减少农田土壤氮素损失,提高氮素利用率,促进农业可持续发展具有指导意义。 展开更多
关键词 生物炭 农田土壤 转化数量 转化速率
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Influence of External Magnetic Fields on Tunneling of Spin-1 Bose Condensate
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作者 YUZhao-Xian JIAOZhi-Yong SUNJin-Zuo 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2期353-356,共4页
In this letter, we have studied the influence of the external magnetic fields on tunneling of the spin-1 Bose condensate. We find that the population transfer between spin-0 and spin-±1 exhibits the step structur... In this letter, we have studied the influence of the external magnetic fields on tunneling of the spin-1 Bose condensate. We find that the population transfer between spin-0 and spin-±1 exhibits the step structure under the external cosinusoidal magnetic field and a combination of static and cosinusoidal one, respectively. Compared with the longitudinal component of the external magnetic field, the smaller the transverse component of the magnetic field is, the larger the time scale of exhibiting the step structure does. The tunneling current may exhibit periodically oscillation behavior when the ratio of the transverse component of the magnetic field is smaller than that of the longitudinal component, otherwise it exhibits a damply oscillating behavior. This means that the dynamical spin localization can be adjusted by the external magnetic fields. 展开更多
关键词 TUNNELING population transfer spinor bose condensate
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Collisional Quantum Interference on Rotational Energy Transfer: Relation Between Integral Interference Angle and Rotational Quantum Number in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14)-Na System
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作者 WANG Wei-Li SONG Peng +2 位作者 LI Yong-Qing MIAO Gang MA Feng-Cai 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期123-129,共7页
Collisional quantum interference (CQI) on rotational energy transfer was observed in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14) system in collision with Na [Chem. Phys. Lett. 318 (2000) 107], and the degree of the inter... Collisional quantum interference (CQI) on rotational energy transfer was observed in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14) system in collision with Na [Chem. Phys. Lett. 318 (2000) 107], and the degree of the interference was measured. The integral interference angle was obtaJned through theoretical calculation. We will research the factors that have effect on collisional quantum interference on rotational energy transfer in Na2(A^1∑u^+,ν=8~b^3∏0u,ν=14)-Na system. Basing on the time-dependent first order Born approximation, and taking into account the anlsotroplc Lennard Jones interaction potentials and "straight-line" trajectory approximation, we obtain the factors that have effect on CQI in Na2-Na system, and obtain the relation between the integral interference angle and rotational quantum number. 展开更多
关键词 rotational energy transfer interference angle rotational quantum number
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小学应用题的教学难点及对策
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作者 周余孝 《中小学教师培训》 1995年第X2期35-36,共2页
关键词 应用题 教学难点 儿童生活 名词术语 教学对策 转化数量关系 小学数学 正确理解 解决问题 解题思路
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Validation of a FFQ (Food Frequency Questionnaire) for Older People
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作者 Jose Eduardo Corrente Dirce Maria Lobo Marchioni Regina Mara Fisberg 《Journal of Life Sciences》 2013年第8期878-882,共5页
Nutrition data for older adults is an area that has few studies mainly in Brazil. Due to the importance to know the behavior of this age group, the aim of this study was to develop and validate a frequency food questi... Nutrition data for older adults is an area that has few studies mainly in Brazil. Due to the importance to know the behavior of this age group, the aim of this study was to develop and validate a frequency food questionnaire (FFQ) for older people in Brazil. It was considered a sample of 73 subjects from the city of Avar6, Sao Paulo, Brazil, and it was applied three 24-hour recalls and a FFQ developed for adults. Data from the three 24-hour recalls were transformed in nutrient intake as well as the data from FFQ. Statistical analysis was performed in order to get correlations between data from the mean of three 24-hour recalls and FFQ for some nutrients. It was found high correlations among them, concluding that the FFQ is valid to get nutrient intakes for older people. 展开更多
关键词 Older people food frequency questionnaire CORRELATIONS nutrient intake.
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