Beam steering in planar photonic crystal based on its anomalous dispersive properties

INTRODUCTION Photonic crystals (PhCs) are increasingly at- tracting attention due to their ability of controlling light propagation on a wavelength scale, by which a fascinating platform for a new generation of inte- grated optical devices and components can be pro- vided. Many studies on PhCs however, focused on new means of tailoring the emission and propagation of light using the photonic band gap (PBG) property whereby the photon density of states is zero. A PhC with a full PBG re…     

关注眼前人[一]

1我看着托盘摔在地上,打得粉碎,午餐也洒了一地。活该,我有些幸灾乐祸地想道,谁叫你盯着我看。他呆呆地站在那里,看着满地的食物发愣。我本来没想过要帮他,但忽     

Evaluation of the dust and methanol extracts of Garcinia kolae for the control of Callosobruchus maculatus （F.） and Sitophilus zeamais （Mots）

Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%-100% whereas in S. zeamais, the mortality ranged from 87.5%-100% and 70%-100% in concentrations of 1 g extract＋3 ml methanol and 1 g extract＋5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract＋l 5 ml methanol had no significant lethal effect on Sitophilus zeamais.     

Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.     

An appraisal of techniques and equipment for cutting force measurement

INTRODUCTION Metal machining processes are characterised mainly by quick changes in quantified elements. In- dividual changes do not occur in isolation and they influence each other. The analysis of these changes require study of the complicated complete systems in their real situations. The study of cutting processes such as turning and facing, from dynamic aspects, is very important. The trend towards the measurement of cutting forces in machining leads to many theo- retical and practic…     

巴州电大教学管理模式及其运行机制的实践及分析

教学模式是在一定的教育理念支配下为实现特定的教学目标而创建的一种教学模型.以转变教育观念为先导,与人才培养模式改革和开放教育项目课题研究相结合,逐步实现以学生个别化自主学习为主,教师导学为辅.多种教学媒体资源综合运用的新的教学模式,建立和完善适合学生个别化自主学习的支持服务体系和质量保证体系,充分应用现代教育技术手段.确保教育质量,积极构建现代远程开放教育条件下培养应用型高等专门人才的新的教学模式.     

中国大陆社区心理学发展的现状、困难与机遇

对CNKI“学术文献总库”中有关社区心理学的研究成果进行检索,使用Endnote的文献管理与分析功能、CNKI的学科类别分组功能以及内容分析法对检索结果进行分析,得出中国大陆社区心理学研究的现状:(1)成果总量不多,2000年以后出现增长趋势;(2)尚未出现特定的“研究中心”,包括具有明显领先优势的研究者或研究机构、集中发表该领域研究成果的专业刊物或出版单位等;(3)出自心理学的研究成果最多(约占成果总数的1/3),其他学科类别依次为医学、社会学及统计学、医疗卫生政策与法律、教育与管理等;(4)研究对象集中于“老年人”和“青少年”两个群体,关注心理健康和心理干预问题;(5)主要采用测量和调查等实证研究方法,研究对社区实践的卷入不深.中国大陆社区心理学的发展面临三重阻力:(1)自上而下的行政化社区管理体制造成公民(包括心理学家在内)社区意识的普遍淡漠,致使社区心理难以进入心理学研究的视域;(2)心理学家普遍重视理论研究,对参与社会实践较少兴趣和经验;(3)实证主义研究范式的心理禁锢.社区心理学在中国同时也面临发展机遇:首先,社会改革与发展过程中涌现出大量的社会心理问题,政府和社会对解决这些问题的迫切需求为社区心理学的发展创造了契机;其次,大型组织和企业积极参与行动研究对社区心理学的发展起到助推作用;第三,心理学学科自身生存与发展的需要为社区心理学的发展提供了内在动力.     

下山才算成功

中国人喜欢把巅峰和登上巅峰当作成功的譬喻,为什么呢?意味着高人一头。于是有这样的诗句:望海能知风浪小,山登绝顶我为峰。     

播种快乐

晚饭后,我正在收拾餐桌,7岁的女儿突然问我:"妈妈,你可不可以给我买个花盆?""花盆?噢,亲爱的,妈妈不会种花,而且妈妈也没时间照顾花。如果你想要什么花,妈妈可以给你买,直接插在花瓶里。"想起每天一大堆待洗的衣服、待收拾的杯盘碗碟、待做的室内清洁、待写的稿件……我整个神经都绷得紧紧的,哪还有时间侍弄花呢。     

选对镜架“眼镜妹”也有春天

没有哪个女孩子不爱美,但是戴眼镜的女孩,如果不注重眼镜的选择,就有可能从"白天鹅"变成"丑小鸭"。其实,只要学会镜架的时尚搭配秘籍,"眼镜妹"也会迎来自己的美丽蜕变!(友情提示:以下小贴士还能用在挑选太阳镜的款式上。)