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长期施肥对土壤生物活性有机碳库的影响 被引量:13
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作者 王平 李凤民 刘淑英 《水土保持学报》 CSCD 北大核心 2010年第1期224-228,共5页
采用土壤培养实验方法,研究了25年施肥对平凉黑垆土土壤生物活性有机碳库(C0)的影响。结果表明:土壤生物活性有机碳库(C0)以施用有机肥处理显著增大,其中以S+NP处理最高,达1071.00μg/g,M+NP处理为940.85μg/g,M处理为776.90μg/g,分别... 采用土壤培养实验方法,研究了25年施肥对平凉黑垆土土壤生物活性有机碳库(C0)的影响。结果表明:土壤生物活性有机碳库(C0)以施用有机肥处理显著增大,其中以S+NP处理最高,达1071.00μg/g,M+NP处理为940.85μg/g,M处理为776.90μg/g,分别比CK增加1.86倍、1.51倍和1.07倍,单施N肥处理对土壤生物活性有机碳库影响不大,为399.10μg/g,仅比CK增加6.4%,NP配合处理为621.60μg/g,比CK增加65.76%。增施有机肥料可明显增大土壤生物活性有机碳库(C0),NP化肥配合施用也有良好效果,N肥单施无明显作用。土壤生物活性有机碳库(C0)占土壤总有机碳(TOC)的百分比为2.70%~6.34%,生物活性有机碳库的周转速率(K)为0.0223~0.0301d-1,生物活性有机碳库在土壤中的半周转期(T1/2)为22.55~31.09d。土壤生物活性有机碳库(C0)与土壤全氮呈极显著性正相关,与总有机碳(TOC)呈显著性正相关。 展开更多
关键词 长期施肥 土壤生物活性有机碳库 周转速率 半周转期
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Method of measuring rotation speed of high spinning projectile based on plane magnetic induction coil
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作者 CAO Yong-hong XUE Kai-yun JING Yong-qiang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第4期317-323,共7页
For the test of rotation speed of high spinning projectile, the general formula of the motional electromotive force (MEMF) of planar magnetic induction coil (PMIC) is derived in case of 3D rotation in a stable mag... For the test of rotation speed of high spinning projectile, the general formula of the motional electromotive force (MEMF) of planar magnetic induction coil (PMIC) is derived in case of 3D rotation in a stable magnetic field. Under a reasona-ble assumption, the MEMF of PMIC is simplified after the aforementioned general formula is used to calculate high spinning PMIC in the geomagnetic field environment. The determination approach of half-cycle is discussed and the method of rotation speed test is studied, and a test is conducted in the paper. The rotation speed curve obtained by the approach in this paper is consistent with the curve by telemetry. 展开更多
关键词 planar magnetic induction coil 3D rotation high spinning projectile determination approach of half-cycle rotation speed test method
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The convergence of Lax-Oleinik semigroup for time-periodic Lagrangian
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作者 LI Xia 《Science China Mathematics》 SCIE 2014年第2期343-352,共10页
In this article,the convergence of so-called Lax-Oleinik semigroup is studied for time-periodic Lagrangian systems when the degree of freedom is greater than 2.Under certain conditions,we show that the Lax-Oleinik sem... In this article,the convergence of so-called Lax-Oleinik semigroup is studied for time-periodic Lagrangian systems when the degree of freedom is greater than 2.Under certain conditions,we show that the Lax-Oleinik semigroup converges if the rotation vector is completely irrational.Removing such conditions,we will give another kind of convergence of the sequence Fc((x,s),(x′,s′+Tn)),the convergence of which is closely related to the Lax-Oleinik semigroup. 展开更多
关键词 Lax-Oleinik semigroup Lagrangian systems Hamilton-Jacobi equation
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