Amorphous Er2O3 films for antireflection coatings

This paper reports that stoichiometric, amorphous, and uniform Er2O3 films are deposited on Si(001) substrates by a radio frequency magnetron sputtering technique. Ellipsometry measurements show that the refractive index of the Er2O3 films is very close to that of a single layer antireflection coating for a solar cell with an air surrounding medium during its working wavelength. For the 90-nm-thick film, the reflectance has a minimum lower than 3% at the wavelength of 600 nm and the weighted average reflectances (400-1000 nm) is 11.6%. The obtained characteristics indicate that Er2O3 films could be a promising candidate for antireflection coatings in solar cells.     

一类连续且处处不可导的函数

在高等数学中,常可看到在一点或数点上连续且不可导的函数,但在一个区问连续且处处不可导的函数却鲜见。历史上,第一个提出这种例子者被认为是德国数学家Weierstrass（1871年）,其实早在1830年捷克数学家Bolzano就已经建立了这种例子,从工程问题中也可得到此类函数,其性质也可得到证明。     

Observation of Dynamic Behavior in YBa2CuaO7-o/La0.88Ca0.12 MnOa Using Femtosecond Optical Pulses

Ultrafast pump-optical probe spectroscopy is used to analyze the carrier dynamic behavior in YBa2 Cua 07-o/La0.88 Ca0.12Mn03 （YBCO/LCMO） heterostructure. The change in reflectivity AR/R is induced and is probed by us- ing pulses of 12Ors duration and photon energy 1.55eV from a Ti：sapphire laser. For higher laser power fluence （such as 0.5 mJ/cm^2）, the time evolution in transient reflectivity change △R/R exhibits three long relaxation processes. We extract the characteristic relaxation time of the different processes by fitting the data and obtain the long characteristic relaxation time which indicates the enhanced proximity effect of the YBCO/LCMO.     

Fabrication, Structural and Magnetic Properties for Aligned MnBi

MnBi compound is fabricated under a magnetic field of 1 T, and the c-axis of hexagonal MnBi crystal is aligned parallel to the magnetic field direction. The saturation magnetization Ms decreases with the increase of temperature. At temperatures below 20OK, the coercive field Hc is about 150Oe, while the coercive field Hc increases with temperature above 200K. From 200K to 300K, the remnant magnetization Mr and the Mr/Ms increase with the temperature. Below 200K, Mr and Mr/M8 reach roughly a constant value. However, there is an abnormal increase at 100 K in He, Mr and Mr/Ms, which comes from a spin-reorientation in MnBi. Magnetization results show the spin-reorientation for MnBi at about 91 K due to the variations of the anisotropy constants.     

太阳能光伏-温差发电驱动的新型冰箱模型设计与热力学分析

结合太阳能电池温度特性和温差发电特点,设计了一套新的太阳能光伏发电-温差发电驱动的冰箱模型,该模型包括太阳能光伏电池、半导体温差发电模块、电源控制系统等.根据负载用电需求,做出了光伏发电系统的设计方案.采用热力学基本理论,对该模型进行了工作效率及 火 用 效率的分析.结果发现:能效比COP达到了2.73(一般 冰箱COP为2左右), 火 用 效率也达到42.5%.同时,该系统模型环境效益明显,可以减排CO₂ 1394.2 kg,SO₂     

对一道拓广探索题的再拓广

人教版八年级《数学》上P27页有一道拓广探索题:如图1,△ABC中,AD是它的角平分线,求证:S△ABD∶S△ACD=AB∶AC.分析这是角平分线性质的运用.按照书上的提示:作DE⊥AB于E,DF⊥AC于F,则由角平分线性质有DE=DF.     

对平行四边形反例的初探

不少版本的八年级《数学》(下)都有一道思考题:一组对角相等、一组对边相等的四边形是平行四边形吗?教师用书的解答是:不一定,并且用图示给出了反例.那么到底何种情况下存在反例,何种情形下不存在反例呢,本文通过对角相等的条件探     

In-Situ Alignment of MnBi Crystals Induced by High Magnetic Field above Curie Temperature

Above Curie temperature, MnBi crystals are aligned in situ along the c-axis in a Bi matrix by a high fabrication magnetic field H f of 10 T. Magnetic testing shows a pronounced anisotropy in magnetization in directions normal and parallel to the fabrication field, resulting from the alignment. The successful alignment m v result from the fact that the easy magnetization direction is along the c-axis of MnBi and the high fabrication field of 10 T is large enough to rotate the ）MnBi crystal to this direction even though the temperature is above the Curie temperature.     

解一题得一类

<正>引题如图1,已知P是正方形ABCD内一点,且PA=5,PB=4,PC=1,求S正.这是《中学生数学》2013年10月下的一道课外练习,供题的姜老师利用旋转法和三角形中的函数关系,最终求得S正=17.受姜老师的启发,本文探究利用勾股定理和正方形的性质来求解,并给出一个更为一般的结论.图1解如图     

纤维缠绕玻璃钢压力容器的声发射特性及爆破强度的预测

前言纤维缠绕玻璃钢压力容器是我国自1958年以来研制的一项新产品,七十年代初已有部颁标准,达到批量生产的阶段。由于该产品具有重量轻、强度高、耐腐蚀、工艺性能优越等许多优点,所以,在工农业生产、航空、国防等很多部门应用。并且,对它的可靠性都要求很严格。多年来,对该 ...