principal root

principal root的基本解释

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主根

与principal root相关的网络例句 [注：此内容来源于网络，仅供参考]

Finally, this dissertation offers suggestions to improve middle school principals\' leadership respectively from the three perspectives of profession, system and subject on the basis of issue investigation and root causes analysis. From the perspective of major, we should place the professional role of school principal on educational leader, and educational leadership is the core professional standard for principals. From the perspective of system, the professional standards and qualification system of the principals should be set up in the pre-entry period, and we should reform the principal\'s selection mechanism and perfect the principal occupation term system in the entry period. we should perfect the systems of duty, training, evaluation and motivation etc.. we should set up healthy work termination system in the principal retirement period. From the perspective of subject, school principals should accurately grasp the meaning of leadership to upgrade the level of education al leadership at multi-levels and in multi paths. Administrators should strive to improve the educational leadership level to realize the professionalization of educational administration, Researchers and trainers should really become the supporters of the principal professional development and leaders of leadership practice improvement.

最后，本文针对调查的问题发现与根源剖析，分别从专业、制度、主体等三个视角提出改进中学校长领导力的对策建议：专业上——应将校长领导力的专业角色定位于教育领导者，教育领导力是校长专业标准的内核所在；制度上——拟入职环节应建立校长专业标准和健全校长资格制度，入职环节应改革校长选拔机制和完善校长任期制度，在职环节应健全校长职责、培训、评估、激励等制度，退职环节应建立健康的校长退出机制；主体上——校长应准确把握领导力内涵、多层次、多途径提升教育领导力水平，教育行政人员应努力提高教育领导水平、逐步实现教育行政专业化，研训者应真正成为校长专业发展的支持者、领导实践改进的引领者。

Based on the analysis on principal root of the different-differential equation, a parameter design method that can achieve the best transient performance is presented.

通过研究差分微分方程组的主根，给出了能够使得控制系统以最快速度达到稳态的参数设计方法。

In order to assess the change of triploid populus tomentoza pulp plantation long-term-site productivity, The paper studied on effects of aboveground litterfall, fine root turnover and wet dust precipitation in nutrient cycling of triploid populus tomentoza pulp plantations at different ages,namely 2a、4a、5a、6a.It studied influence of different factors on decomposition of leaf、tree bark and twig of triploid populus tomentoza to select the operations to accelerate the decomposition and nutrient release. Finally, it studied influence of different intercrops on plantation site productivity and the relationship of intercrops and triploid populus tomentoza to select suitable intercrops. The main results as follows:(1)The aboveground litterfall of triploid populus tomentoza increased along with age from 216.03±59.7gm~(-2) at 3a to 482.38±101.3gm~(-2) at 7a, The N returned by litterfall wasl8.38±2.46kg.hm~(-2)a~-121.63±2.25kg.hm~(-2a~-139.51±4.61kg.hm~(-2a~-138.89±4.89kg.hm~(-2a~(-1) at 3a、5a、6a、7a respectively. The P returned by litterfall was 5.80±0.62kg.hm~(-2)a~(-1)、8.16±0.94kg.hm~(-2)a~(-1), 11.31±1.33kg.hm~(-2)a~(-1)、11.76±1.37kg.hm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The nutrient returned by fine root turnover increased along with age, too. The N returned by fine root turnover was 3.85±0.41kghm~(-2)a~(-1)、5.22±0.63kghm~(-2)a~(-1),7.62±0.89kghm~(-2)a~(-1),9.17±1.22kghm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The P returned by fine root turnover was 0.73±0.07kghm~(-2)a~(-1)、1.69±0.09kghm~(-2) a~(-1)、1.92±0.31kghm~(-2)a~(-1)、1.96±0.21kghm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The leaf was the principal pathway to return nutrient to soil among litterfall, fine root turnover and wet dust precipitation. The proportion of returned N by leaf was 74.84%、71.96%、78.58%、75.03% at 3a、5a、6a、7a respectively,The proportion of returned P by leaf was 85.93%、80.31%、83.04%、83.23% at 3a、5a、6a、7a respectively. Therefore, it is important to protect and utilize the leaf in order to maintenance and enhance the long-term-site productivity of triploid populus tomentoza pulp plantation.

本文采取时序研究法，以3a、5a、6a、7a共4个不同年龄的三倍体毛白杨纸浆林为对象，研究了地上凋落物、细根周转、湿沉降在林分N、P营养元素循环中的作用及不同年龄林分N、P营养元素循环的特征，以评价三倍体毛白杨纸浆林长期立地生产力的变化；采取网袋法研究了不同因素对落叶、树皮、树枝分解的影响，以确定加快其分解、促进养分释放的措施：同时研究了不同间作物对林地影响、林木与间作物之间关系，以选择能维持立地生产力的合适的间作物种类等内容，得到以下结论：(1)随着年龄的增加，三倍体毛白杨地上凋落物的数量从3a的216.03±59.7gm~(-2)增加到7a的482.38±101.3gm~(-2)，通过凋落物归还的N分别为：3a时为18.38±2.46kg.hm~(-2)a~(-1)，5a时为21.63±2.25kg.hm~(-2)a~(-1)，6a时为39.51±4.61kg.hm~(-2)a~(-1)，7a时为38.89±4.89kg.hm~(-2)a~(-1)，归还的P分别为：3a时为5.80±0.62kg.hm~(-2)a~(-1)，5a时为8.16±0.94kg.hm~(-2)a~(-1)，6a时为11.31±1.33kg.hm~(-2)a~(-1)，7a时为11.76±1.37kg.hm~(-2)a~-1随着年龄的增加，通过细根周转归还的养分也在增加，归还的N分别为：3a时3.85±0.41kghm~(-2a~(-1)，5a时5.22±0.63kghm~(-2)a~(-1)，6a时7.62±0.89kghm~(-2)a~(-1)，7a时9.17±1.22kghm~(-2)a~-1归还的P分别为：3a时0.73±0.07kghm~(-2a~(-1)，5a时1.69±0.09kghm~(-2)a~(-1)，6a时1.92±0.31kghm~(-2)a~(-1)，7a时1.96±0.21kghm~(-2)a~-1从地上凋落物、细根周转、湿沉降三种不同途径归还林地养分所占的比例来看，地上凋落物中的落叶是归还养分主要途径，年龄在3a、5a、6a、7a时，通过落叶归还的N所占比例分别为74.84%、71.96%、78.58%和75.03%，归还的P所占比例分别为85.93%、80.31%、83.04%和83.23%。

与principal root相关的网络解释 [注：此内容来源于网络，仅供参考]

principal adele：症代尔

primitive root 原根 | principal adele 症代尔 | principal anti automorphism 执自同构

principal curve：主曲线

主立方根 principal cubic root | 主曲线 principal curve | 主次数 principal degree

principal solution：主解

主页;主枝 principal sheet | 主解 principal solution | 主平方根 principal square root