昆虫抗寒性的生理机制及影响因子   总被引：1，自引：0，他引：1  

梅增霞  李建庆 《滨州学院学报》2006,22(3):57-61

昆虫是外温动物,在长期的进化过程中形成了一整套适应不良低温环境的抗寒机制.现主要总结了耐寒昆虫与耐冻昆虫对低温适应的生理机制以及环境因子对昆虫抗寒能力的影响作用.  相似文献   

In these uncertain times: Educators build cultural awareness through planned international experiences   总被引：1，自引：0，他引：1  

John Kambutu  Lydiah W. Nganga 《Teaching and Teacher Education》2008

This narrative inquiry explored the effectiveness of planned international experiences in promoting cultural awareness, understanding and appreciation among American educators. Participating educators (n=12) were immersed in foreign cultures for 2–3 weeks during three different summers. To document the effectiveness of cultural immersion, participants completed pre- and post-visit surveys. Pre-visit data showed lack of cultural awareness. After the visit, however, participants had gained broader awareness, understanding and appreciation of host cultures such that familiar cultural practices were rarely used as the only point of reference. Follow-up interviews showed possible sustained acculturation.  相似文献   

Genuine Religious Tolerance: Is It a Thing of the Past in Public Schools?     

Paul A. Wagner  Lillian Benavente-McEnery 《Interchange》2008,39(3):327-350

The so-called Culture Wars have made the issue of religious tolerance in schools more confusing than ever. Where once free speech trumped nearly every concern in these wars in the public schools, there is now great concern about whether messages put out are politically correct. The preoccupation teachers now have with avoiding speech or themes likely to get them into trouble has led to a new form of censorship. The authors explain that free speech in the educational forum requires respect for every earnest attempt to get at a legitimate truth claim. In matters religious, this epistemic openness is no longer respected. The argument below does not encourage teachers to engage in debate among students in matters religious, or even to encourage it. Nor are the arguments below aimed at introducing religious discourse as a means of developing skills of critical thinking as the feminist, moral philosopher Nel Noddings has previously recommended. The argument simply concludes with the modest recommendation that teachers be more conscientious about indirectly censoring or trivializing student religious speculations.  相似文献   

耦合故障下增程器不对中故障诊断特征变化研究     

吴强 《武汉工程职业技术学院学报》2020,(1):1-5

在增程器失火-不对中耦合故障下,通过多工况下虚拟样机仿真,对不对中故障的故障诊断特征的变化规律展开了研究。借助虚拟样机平台搭建了某款增程器虚拟样机刚柔混合模型;对已经探索得到的不对中故障诊断特征,在多转速、多失火状态工况下,研究耦合故障下不对中故障特征变化规律;对耦合故障下的增程器转子系统进行动力学分析,结合机理研究,对不对中故障诊断特征的变化进行了原理分析;由此得到耦合故障工况下不对中故障诊断特征变化规律。  相似文献   

On-line broken-bar fault diagnosis system of induction motor     

张荣  王秀和 《天津大学学报(英文版)》2008,14(2):144-147

Induction motor faults including mechanical and electrical faults are reviewed. The fault diagnosis methods are summarized. To analyze the influence of stator current, torque, speed and rotor current on faulted bars, a time-stepping transient finite element (FE) model of induction motor with bars faulted is created in this paper. With wavelet package analysis method and FFT method, the simulation result of finite element is analyzed. Based on the simulation analysis, the on-line fault diagnosis system of induction motor with bars faulted is developed. With the speed of broken bars motor changed from 1 478 r/min to 1 445 r/min, the FFT power spectra and the wavelet package decoupling factors are given. The comparison result shows that the on-line diagnosis system can detect broken-bar fault efficiently.  相似文献   

行波测距技术在电力系统中的应用     

陈一文 《广东教育学院学报》2008,28(3):54-56

电力系统输电线路发生故障后,利用阻抗原理的测距装置测距误差较大,而利用行波测距技术可以实现精确故障定位．行波测距技术的优越性在于精度高、适用性强、方便使用等,行波测距技术在超高压输电线路中被成功应用,这一技术在电力系统中将有着广阔的发展前景．  相似文献   

滇东南建水二叠纪火山岩地球化学特征及其构造意义   总被引：5，自引：0，他引：5  

谢静  常向阳  朱炳泉 《中国科学院研究生院学报》2006,23(3):349-356

滇东南建水地区二叠纪火山岩构造侵位于师宗-弥勒断裂带的西南段，以玄武岩、玄武安山岩和安山岩为主，夹有少量苦橄岩。地质、地球化学特征显示其形成于弧后盆地环境，与建水地区石炭纪枕状熔岩相配套。显示扬子陆块和华夏陆块在晚古生代发生了板块俯冲，形成岛弧火山岩，二叠纪时产生弧后引张，形成弧后盆地。从晚古生代-早中生代，扬子陆块和华夏陆块之间可能存在一个复杂的沟弧盆体系。  相似文献   

缔约过失责任的法理基础研究     

罗许生  徐长斌 《重庆职业技术学院学报》2005,14(2):148-150

传统契约理论认为契约责任以契约有效为前提，无契约则无责任。1861年德国法学家耶林创造了缔约过失责任，从而扩大了合同责任的适应范围，产生了极为深远的影响，我国合同法亦确认了缔约过失责任。但当事人基于违反了什么样的义务而承担责任．对方当事人的请求权基础是什么却存在很大争议。本文从缔约过失责任产生的来源及对各种学说的分析批判中得出诚实信用原则为其请求权基础．  相似文献   

Improving network service performance and reliability via links trunking technologies     

GUO Hui WANG Yun-peng WANG Zhi-guang ZHOU Jing-li 《浙江大学学报(A卷英文版)》2006,7(6):1001-1007

INTRODUCTION Because of the critical role that computing sys-tems and networks play in today’s business envi-ronment, it is not surprising that business success often goes to the company with the best information and the most efficient process for delivering that in-formation. As the principal tool for business col-laboration, corporate LANs are a vital resource in enabling today’s enterprises to adopt competitive strategies. The number of users wanting to share and access data across…  相似文献   

无过错责任原则在环境侵权中的适用     

费艳颖  倪乃迪  曹雪飞 《辽宁师范大学学报(社会科学版)》2006,29(2):26-28

无过错责任原则,是指加害人对损害的发生无论是否有过错均应承担赔偿责任。相应的,环境侵权的无过错责任,即是指行为人的环境污染行为给他人造成了损害,除法定的免责情况外,不论其有无过错,均应对损害结果负责。目前我国学界对环境侵权的归责应否采用无过错原则存在较大争议。这里从对环境侵权行为的多角度分析入手,认为适用无过错责任原则更有利于环境保护,实现社会本位的现代社会发展理念;同时,在适用这一原则时应加以必要的限制,以保证法律的公正性,实现立法目的。  相似文献