相分离体系Nd0．85Sr0．15CoO3的弛豫现象

本文系统地研究了Nd0．85Sr0．15CoO3的弛豫行为．低温下,零场冷却和带场冷却测量曲线呈现镜像对称,并且弛豫行为遵循扩展指数关系．这表明铁磁团簇间的相互作用导致了体系的相分离,从而证实了在Nd0．85Sr0．15CoO3体系中铁磁团簇间的相互作用和自旋玻璃相共同导致了低温时的相分离．     

富Mn型MnNiGa Heusler合金的磁性能及交换偏置效应

为了理解和丰富交换偏置现象,对富Mn型Heusler合金的磁性能和交换偏置效应及随其成分的演变规律进行了研究.利用电弧熔炼法制备Mn50 Ni50-xGax(x=14,10,6,2)系列合金,通过直流热磁曲线测试分析各组分合金在降温过程中出现的磁性团簇;然后利用低温下磁滞回线测试计算并研究不同Mn成分下合金的交换偏置效...     

交流复阻抗技术在CaTi0.85Sc0.15O3-α固体电解质中的应用

介绍了交流复阻抗测试技术在固体电解质测试中的应用原理，并对用传统固相反应法合成的样品CaTi0．85Sc0．15O3-α进行了实际应用测试。根据测得的阻抗谱提出了相应的等效电路，用阻抗分析软件对CaTi0．85Sc0．15O3-α在不同温度下的交流阻抗测试结果进行了对比拟合处理，获得了晶粒电阻、晶界电阻，并定量研究了样品中晶粒电导、晶界电导和总电导随测试温度的变化特性。结果表明：Sc掺杂显著提高了样品的电导性能，CaTi0．85Sc0．15O3-α在800℃的电导率达到0．017S／cm，接近于同温度下8YSZ的电导率；在整个测量温度范围内，电导率与温度的关系满足Arrhenius定律，晶界活化能大于晶粒活化能，样品在730℃以下电导率主要取决于晶界电导，在730℃以上电导率主要由晶粒电导所决定。     

钕存在下二阶导数光谱直接测定镱

在Nd3+、Yb3+共存的RE-XO-CPC弱酸性介质体系中,加入F-可有效地掩蔽Nd3+.选用L16(45)正交表进行试验,得到最佳实验条件为[XO]=1.31×10-4mol·L-1,[CPC]=4×10-4mo·L-1,[F-]=8×10-4md·L-1.二阶导数峰(+617.5 nm)-零法、零-谷(-592.8nm)法、峰(+617.5 nm)-谷(-592.8 nm)法测定Yb3+时,3倍量的Nd3+不干扰测定,直线回归方程分别为y=9.47×10-3+2.47×10-3x(峰-零法,相关系数p=0.9990);y=1.70×10-3+6.56×10-3x(零-谷法,p=0.9998);y=2.64×10-3+1.07×10-2x(峰-谷法,p=0.9949).用零-谷法对不同配比Nd3+、Yb3+混合物进行分析,平均偏差在12.0%-24.0%,变异系数在1.80%-6.98%.     

Sensitized Up—Conversion Luminescence of Ho^3＋ in Nd^3＋—Yb^3＋—Ho^3＋ Co—doped ZrF4—Based Glass

Up-conversion processes for the blue, green and red emissions were found two-photon phenomenon, known as the cooperative phenomenon. This phenomenon was assisted by Nd³⁺ → Yb³⁺ → Ho³⁺ energy transfer. The strong green emission due to the Ho³⁺ : (⁵F₄, ⁵S₂)→ ⁵I₈ transitions was observed in Nd³⁺-Ho³⁺ co-doped ZrF₄-based fluoride glasses under 800 nm excitation. As an attempt to enhance Ho³⁺ up-conversion luminescences in the Nd³⁺ – Ho³⁺ co-doped ZrF₄-based glasses, Yb³⁺ ions were added to the glasses. As a result it was found that, in 800 nm excitation of 60 ZrF₄. 30BaF2. (8-x)LaF₃. lNdF₃. xYbF₃. 1HoF₃ glasses (x=0 to 7), sensitized up-conversion luminescences are observed at around 490 nm (blue), 545 nm (green), and 650 nm (red), which correspond to the Ho³⁺ : ⁵F₃ → ⁵I₈, ( ⁵F₄, ⁵S₂)→⁵I₈ and ⁵F₅→ ⁵I₈ transitions respectively. The intensities of the green and red emissions in a 3 mol % YbF₃-containing glass were about 50 times stronger than those glasses without YbF₃. This is based on sensitization due to Yb³⁺ ions. In particular, the green emission was extremely strong and the Nd³⁺-Yb³⁺-Ho³⁺ co-doped ZrF₄-based glasses have a high possibility of realizing a green up-conversion laser glass. In this paper the up-conversion mechanism in the glasses is discussed in detail.     

Nd3+-Yb3+-Ho3+掺杂四氟化锆玻璃的Ho3+上转换特性研究

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｉｎｒｅｃｅｎｔｙｅａｒｓ ,ｈｉｇｈ ｐｏｗｅｒｌａｓｅｒｄｉｏｄｅｓｈａｖｅｂｅｅｎｅｍｐｌｏｙｅｄａｓｐｕｍｐｉｎｇｓｏｕｒｃｅｓｗｉｔｈａｖｉｅｗｔｏｄｅｖｅｌｏｐｃｏｍｐａｃｔｕｐ ｃｏｎｖｅｒｓｉｏｎｖｉｓｉｂｌｅ ｌａｓｅｒｓｙｓｔｅｍｓ .Ｔｈｅｆｒｅ ｑｕｅｎｃｙｃｏｎｖｅｒｓｉｏｎｏｆｉｎｆｒａｒｅｄｌｉｇｈｔｔｏｖｉｓｉｂｌｅｌｉｇｈｔｈａｓｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｉｎｖｅｓｔｉｇａｔｅｄｆｏｒｒａｒｅ ｅａｒｔｈｄｏｐｅｄｃｒｙｓｔａｌｓａｎｄｇ…     

课件制作中如何将磁带转录制作成mp3

1准备器材 准备一条双头音频线(两端都是立体声耳机那样的插头)，一般的音响元件店都有出售，实在没有也可以自己制作：找两根报废的单放机耳机(普通三芯插头)，去掉耳塞头，并将左右音频线对接，对接时要对号入座，不要接错。然后，把双头音频线的一端接入单放机的耳机输出插口。另一端插入计算机声卡的“Line In”(线路输入)接口。     

介质中电磁场统一性质的三维表示

对文[1]结果进行了推广，导出了一般情况下用统一场量表示的Maxwell方程组、边界条件和其他电磁场量。     

基于Maxwell 3D磁场分析的直线电动机仿真实验

特种电动机的教学是常规电动机教学工作的延续,电动机的结构和磁场分布与常规电动机有所不同,特别是各种场的概念非常抽象。为提高学生学习兴趣,使学习的电动机内容更加直观,本文以平板式永磁直线电动机为例,利用Maxwell3D软件进行建模仿真。在仿真中定义了电动机各部分材料属性,然后对定子和动子进行剖分设置,加载边界条件,求解及后处理。分析了电动机的磁场和电流密度,直观的展现了电动机磁场分布和力矩信息。加强学生理解直线电动机的基本结构和工作原理,使非常抽象的磁场和电场概念具体化、形象化,培养了学生想象力和创造力。本文方法对于其它种类的电动机教学也具有参考作用,为今后开展电动机方面虚拟实验打下基础。     

Osteogenic effects of antihypertensive drug benidipine on mouse MC3T3-E1 cells in vitro

Hypertension is a prevalent systemic disease in the elderly, who can suffer from several pathological skeletal conditions simultaneously, including osteoporosis. Benidipine(BD), which is widely used to treat hypertension, has been proved to have a beneficial effect on bone metabolism. In order to confirm the osteogenic effects of BD, we investigated its osteogenic function using mouse MC3 T3-E1 preosteoblast cells in vitro. The proliferative ability of MC3 T3-E1 cells was significantly associated with the concentration of BD, as measured by methylthiazolyldiphenyl-tetrazolium bromide(MTT)assay and cell cycle assay. With BD treatment, the osteogenic differentiation and maturation of MC3 T3-E1 cells were increased,as established by the alkaline phosphatase(ALP) activity test, matrix mineralized nodules formation, osteogenic genetic test,and protein expression analyses. Moreover, our data showed that the BMP2/Smad pathway could be the partial mechanism for the promotion of osteogenesis by BD, while BD might suppress the possible function of osteoclasts through the OPG/RANKL/RANK(receptor activator of nuclear factor-κB(NF-κB)) pathway. The hypothesis that BD bears a considerable potential in further research on its dual therapeutic effect on hypertensive patients with poor skeletal conditions was proved within the limitations of the present study.     

Positive temperature coefficient of resistivity effects of semiconducting (Bi1/2Na1/2) TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y3+-doped (Bi1/2Na1/2)TiO3-CaTiO3-BaTiO3 (BNCBT) positive temperature coefficient of resistivity (PTCR) ceramics sintered in air atmosphere were investigated in this study. (Bi1/2Na1/2) TiO3 (BNT) component can remarkably increase the onset temperature Tc of PTCR ceramics with the expensive of the resistivity R25 increase. CaTiO3 (9-27 mol%) component can decrease the resistivity, and adjust the effects of BNT phase on the Tc point. For the sample containing 3 mol% CaTiO3, the Tc raises from 122° to 153° when only 0.6 mol% BNT added, while for the ones with higher CaTiO3 content (9-27 mol%), Tc is only increased by a rate of 8-9°/1.0 mol% BNT. The effects of BNT and CaTiO3 components on Rmln (negative temperature coefficient effect) are also discussed.     

Positive temperature coefficient of resistivity effects of semiconducting （Bi（1/2）Na（1/2））TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT） component can remarkably increase the onset temperature T c of PTCR ceramics with the expense of the resistivity R 25 increase. CaTiO 3 （9–27 mol%） component can decrease the resistivity, and adjust the effects of BNT phase on the T c point. For the sample containing 3 mol% CaTiO 3 , T c raises from 122 ℃ to 153 ℃ when only 0.6 mol% BNT added, while for the ones with higher CaTiO 3 content （9–27 mol%）, T c is only increased by a rate of 8–9℃/1.0 mol% BNT. The effects of BNT and CaTiO 3 components on R25/Rmin （negative temperature coefficient effect） are also discussed.