查询词典 principal root

Root-derived organic carbon is composed of three compartments: root detritus, root eaudates and root symbionts, which represents a large important and potential C sink in forest ecosystems, The known responses of root derived organic carbon and heterotrophic microbes to elevated CO2 were reviewed. Overall, increases in root biomass, productivity, and exudation indicate an augmentation of C inputs into the soil via roots, although changes in root lifespan are still unclear and may modify this flux positively or negatively, Altogether, changes in root chemistry and morphology that may augment soil C storage under elevated CO2 include decreased N concentration and wider root diameter, Alternately, a shift in rooting depth upwards in the soil profile may increase average turnover rates of root detritus. Effects of CO2 concentration on C qualities of root exudates and root symbionts are the least understood components discussed here, Changes of soil heterotropic microbial activity and community under elevated CO2 still remained large uncertainties.

林木根源有机C包括根东通过根枯落物、根系分泌物和根共生菌周转3条途径向土壤输入的有机C，它是森林生态系统中一个重要的、潜在的C汇，综述了根源有机C与其微生物对CO2浓度升高的响应，虽然对根系寿命的变化尚不清楚，但CO2浓度升高将导致根系生物量、生产量、死亡量和分泌物的增加；同时，CO2升高亦促使根共生菌生物量的增加而增加了共生菌的C归还潜力，表明CO2升高使根源有机C的输入增加了，CO2农度升高情况下，根系化学性质和形态特征的这些变化均有利于增加土壤C的吸存；而根分布深度的降低则对土壤C吸存不利；CO2浓度升高对根分泌物和根共生菌质量的影响研究则极少，CO2浓度升高下土壤微生物活性和群落组成的变化存在较大的不确定性，目前CO2浓度升高下林木根源有机C对森林长期C吸存的贡献仍很不清楚。

In order to support and perfect the professionalization of principals, a series of systems are needed, which include the systems of principal's qualification, principal's selection, principal's responsibility, principal's term, principal's rank, principal's training, principal's supervision, principal's yearly salary and principal's withdrawal.

实现校长的专业化地位，必须有外部的一系列制度来加以支持与完善。这些制度与措施是校长资格制度、校长选拔制度、校长负责制度、校长任期制度、校长职级制度、校长培训制度、监督校长制度、校长年薪制度、校长退出制度。

The plastic deformation induced due to cyclic rotation of principal stress axes alone can be in the same magnitude as that due to shear with fixed principal stress axes. 2 The volumetric strain due to shearing of cyclic rotation of principal stress axes is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. The former is characterized by its reversibility and is independent of past shear history, the latter by its irreversibility increases with the increase of cycle number yet its increase rate decreases with its accumulation. 3 The obvious non-coaxiality between directions of the principal stresses and principal strain increments is found and its degree depends largely on the change of shear stress component. 4 The intermediate principal stress has considerable effects on the deformation behavior of sands in the condition of cyclic rotation of principal stress axes. The accumulation rate of the irreversible dilatancy component increases with the increase of the intermediate principal stress parameter.

具有初始各向异性的砂土在纯应力主轴循环旋转排水条件下的主要变形规律为：①纯应力主轴循环旋转可产生与应力主轴固定单调剪切处于同一数量级的塑性变形；②纯应力主轴循环旋转引起的剪切体变包含可逆性剪切体变分量和不可逆性剪切体变分量两部分，其中可逆性剪切体变分量在一周内可完全恢复，基本与应力历史无关；不可逆性剪切体变分量随循环周数的增加呈单调增加，且增加速率随其自身累积值的增大呈减小趋势；③应变增量主轴与应力主轴之间的非共轴现象显著，且在一周内具有分段性；④中主应力对应力主轴循环旋转条件下砂土的变形特性有重要影响，不可逆性剪切体变分量的累积速率随中主应力系数的增加而增加。

Hairy roots were induced from tobacco leaves with Agrobacterium rhizogenes LBA1334 harboring agropin type PRil855 and binary vector PIG121HM carrying a kanamycin resistant gene nptll and GUS gene and the good hairy root clones were selected. The root with many root hairs and branches grew vigorously toward all the direction on MS medium without plant hormone and on kanamyain containing medium (km:30mg/L). The structure of the hairy root tip is different from that of ordinary root. Witch was not typical root cap maybe the main cause of losing the geotropism of hairy root. Plantlet regenerated from hairy root when cultured on Ms medium without plant hormone. The nicotine content of the hairy root was little higher than that in the natural roots.

本研究通过发根农杆菌工程菌LBA1334(含有野生型pRi1855质粒和pIG121HM双元载体质粒，编码NPTⅡ基因和GUS基因)转化烟草沙姆逊，获得了具有卡那霉素抗性烟草发状根，并筛选出良好的单克隆株系，该发状根具有典型的发状根特性(多根毛、多分支、在无激素培养基上快速生长)，通过根尖压片分析，烟草发状根不具备典型的根冠；发状根中烟碱含量1.61％稍高于与天然栽培品种母体根的含量(1.5％左右)，发状根向培养液中释放烟碱，释放量最多时占总烟碱量的81.1％；在无激素的培养基上获得了再生植株。

The root hair morphology of cv. RM109 was observed and compared. The results indicated that in the distance of 1 cm to the apical of seed root, the number of root hair of RM109 was 19% of cv. Oochikara, and the root diameters were not different from cv. Oochikara; in the distance of 8 cm, the number of root hair and the root diameters of RM109 were 45% and 79% of cv. Oochikara, in the distance of 3 cm, the length of the longest root hair was 33% of cv. Oochikara; but the length from the apical of the seed root to root hair initiation was not different.

根毛观察比较显示，距种子根根端1 cm处的RM109根毛数是&大力&品种的19%，差异极显著，根直径与&大力&品种差异不显著；距根端8 cm处的RM109根毛数和根直径分别是&大力&品种的45%和79%，二者差异极显著；距根端3 cm处，RM109最大根毛长是&大力&品种的33%，差异极显著；RM109种子根根端到根毛发生区的长度，与&大力&品种的差异不显著。

The main achievements could be summarized as follows.1. The basic stress-strain characteristics and related physical mechanisms for sands under cyclic rotation of principal stress axes were investigated based on three kinds of drained tests including fixed principal stress axes, cyclic rotation of principal stress axes with magnitudes of principal stresses kept constant, and cyclic changes of principal stresses in both their axes and magnitudes. The main deformation behavior of sands with inherent anisotropy under cyclic rotation of principal stress axes with magnitudes of principal stresses kept constant was obtained in the following.

本文从试验研究、规律分析、数学建模和工程应用四个方面，对应力主轴循环旋转条件下砂土的变形特性进行了较为深入的研究，取得了如下主要研究成果：(1)基于对饱和砂土进行的主轴固定单调剪切、纯应力主轴循环旋转以及主应力幅值与应力主轴耦合循环变化的三类完全排水试验成果，分析和揭示了应力主轴循环旋转条件下砂土的基本变形规律，并探讨了其受力变形的内在机理。

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。

Experiments were conducted for testing root tensile strength and measuring root cellulose content of Medicago sativa and Digitaria sanguinalis. Results indicated that in the two species, both the tensile strength and percentage of cellulose were negatively correlated with root diameter, while a positive correlation was found between percentage of cellulose and tensile strength. The conclusion confirmed that the relationship among root tensile strength, root diameter and root cellulose content found in tree root system was held also in the two species.

对豆科的紫花苜蓿和禾本科的马唐根的抗拉力和纤维素含量的研究表明，根的抗拉强度和纤维素含量均与直径呈显著的负相关关系，根的抗拉强度与纤维素含量呈正相关关系，表明&木本植物根的抗拉强度、直径和纤维素含量关系&的研究结论在这两种草本植物上也同样适用。

The results show:(1) After soybean seed is treated with seed coating, The length of lateral root anlage Initiating area obviously increases in contrast with control (seed which is not coated with agent is regarded as control; shortened form is CK).The order is from greatness to smallness in turn as follow: HK＞ND＞CK.(2) Initiating progress of lateral root anlage is quickened when seed is treated with seed coating. General trend is as follow: HK＞ND＞CK. By variance analysis, treatment and control has obvious difference.(3) Initating status of lateral root anlage is definite related with contents of endogenous hormone. Occurring of lateral root is as the result of some endogenous hormone corresponded and playing manysided role, especially IAA plays important role in the cause of inducing to occurring of lateral root anlage.(4) The use of seed coating may elevate the number of lateral root anlage occurring and shorten the time of lateral root anlage occurring, especially the effect of Chemical control seed coating is better.

结果表明：(1)种衣剂包衣后，侧根原基发生区长度明显比对照(不包衣的种子为对照，用CK表示)增加，从大到小依次为：HK＞ND＞CK；(2)种衣剂处理加快了侧根原基的发生进程，总的趋势是HK＞ND＞CK，经F检验表明，处理和对照差异极显著；(3)侧根原基的发生状况与侧根原基发生区内源激素的含量有一定的关系，侧根的发生是几种植物内源激素相互协调、综合作用的结果，其中生长素类物质在诱导侧根原基的发生过程中起主导作用；(4)应用种衣剂可以提高侧根原基发生的数量，缩短侧根原基的发生时间，其中以化控种衣剂效果最好。

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%。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。