（Na0.52K0.44Li0.04）Nb0.9-xSbxTa0.1O3 Lead-Free Piezoelectric Ceramics with High Performance and High Curie Temperature

（Na0.52K0.44Li0.04）Nb0.9-x Sbx Ta0.1O3 lead-free piezoelectric ceramics are prepared by a solid-state reaction method. With increasing Sb content, the transition temperature from orthorhombic to tetragonal polymorphic phase decreased. A composition （Na0.52K0.44Li0.04）Nb0.863Sb0.037Ta0.1O3 is found to possess excellent piezo- electric and electromechanical performances （d33 = 306pC/N, kp =48%, and kt=50%）, and high Curie temperature （Tc = 320 ℃）. These results indicate that （Na0.52K0.44Li0.04）Nb0.863Sb0.037 Ta0.1O3 is a promising lead-free piezoceramics replacement for lead zirconate titanate.     

Symmetric Telecloning and Entanglement Distribution of Spin Quantum States

We propose a physical realization of symmetric telecloning machine for spin quantum states. The concept of area average fidelity is introduced to describe the telecloning quality. It is indicated that for certain input states this quantity may come to an enough high level to satisfy the need of quantum information processing. We also study the properties of entanglement distribution via the spin chain for arbitrary two-qubit entangled pure states as inputs and find that the decay ratio of entanglement for the output states is only determined by the parameters of spin chain and waiting time, independent of the initial input states.     

Effects of Li Substitution and Sintering Temperature on Properties of Bi0.5（Na,K）0.5TiO3 Lead-Free Piezoelectric Ceramics

Bi0.5 （Na0.72K0.28- x Lix ）0.5 TiO3 （BNKLT- 100x） lead-free piezoelectric ceramics are synthesized by conventional solid state sintering techniques. The dielectric and piezoelectric properties of the BNKLT-100x ceramics as a function of Li content are systematically investigated. It is found that not only Li content but also the sintering temperature has a strong effect on the piezoelectric properties of BNKLT. The piezoelectric constant d33 Of BNKLT varies from 120 to 252pC/N in the Li content range from 0.03 to 0.16. In the sintering temperature range from 1080 to 1130℃, the d33 value of BNKLT-6 changes from 200pC/N to 252pC/N. The BNKLT-6 sample sintered at 1100℃ has the highest piezoelectric constant d33 of 252pC/N, with the electromechanical coupling factors kp of 0.32 and kt of 0.44.     

Demonstration of a 4H SiC Betavoltaic Nuclear Battery Based on Schottky Barrier Diode

A 4H SiC betavoltaic nuclear battery is demonstrated. A Schottky barrier diode is utilized for carrier separation. Under illumination of Ni-63 source with an apparent activity of 4mCi/cm^2, an open circuit voltage of 0.49 V and a short circuit current density of 29.44nA/cm^2 are measured. A power conversion efficiency of 1.2% is obtained. The performance of the device is limited by low shunt resistance, backscattering and attenuation of electron energy in air and Schottky electrode. It is expected to be significantly improved by optimizing the design and processing technology of the device.     

退火对Pb辐照Al2O3单晶发光特性的影响

研究了230MeV的²⁰⁸Pb²⁷⁺辐照Al₂O₃样品及随后在600,900,1100K高温条件下退火后的光致发光特性。从辐照样品的测试结果可以清楚地看到在波长为390,450nm处出现了强的发光峰。辐照量为1×10¹³ions/cm²时,样品的发光峰最强。经过600K退火2h后测试结果显示,380nm发光峰剧烈增强,而其他发光峰显示不明显。在900K退火条件下,380nm的发光峰开始减弱,而在360,510nm出现了明显的发光峰,至到1100K退火完毕后380nm的发光峰完全消失,而360,510nm的发光峰相对增强。从被辐照样品的FTIR谱中看到,波数在460~510cm^-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al₂O₃振动吸收峰消失,说明Al₂O₃振动模式被完全破坏。1000~1300cm^-1之间为Al—O—Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动,说明其振动模式受到影响。辐照剂量较小的样品,损伤程度相对较低,经退火晶化后,振动模式基本恢复到单晶状态;辐照剂量较高的样品,损伤程度大,退火处理后表面变得较粗糙,振动模式并未出现,说明结构破坏严重。     

椭圆型保偏光纤耦合器的研制

保偏光纤耦合器是干涉仪和光纤陀螺仪的关键器件。介绍了用匹配型椭圆包层保偏光纤制作保偏光纤耦合器的工艺流程、测试结果以及分光比随温度的变化情况。试验结果表明,保偏光纤耦合器的综合性能指标,尤其是附加损耗和温度性能达到了国内领先水平。     

采用罗戈夫斯基线圈诊断径向束流

 罗戈夫斯基线圈具有结构简单、高频特性好等特点而被广泛应用于脉冲电流测量。提出了用两个自积分式罗戈夫斯基线圈诊断径向束流的方法,在此基础上设计了两个用于径向束流诊断的自积分式罗戈夫斯基线圈,对其进行了标定。当标准电流的上升沿为30 ns时,罗氏线圈响应时间约为10 ns;整个系统的测量误差约为4.7%。从标定结果来看,该系统的频率响应特性和测量精度能够满足ns级束流诊断的要求,该方法可以用于径向结构高功率微波器件的束流强度测量。     

半色调双面图像的色彩预测Clapper-Yule模型

为了准确地预测印刷图像的光谱反射率,在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的近似下,利用考虑光在纸基内多次内反射的Clapper-Yule理论和描述多重内反射的网状结构分析模型,建立了同色不同加网周期双面墨像的光谱反射色彩预测模型.同时给出了包含纸基的向下体反射和反面纸基-空气构成界面定向反射作用的单面墨像Clapper-Yule色彩预测修正新模型.     

手机导光板熔合微光学阵列研究

为了研究手机侧发光背光模组,理论分析并模拟了在导光板表面直接熔合微光学结构的手机背光系统.结果表明,熔合微光学结构后,手机背光系统的出射光场发生变化,使得部分光线在偏离视场中心55°的方向上会聚,为设计新型集成手机微光学导光板奠定基础.     

枯草杆菌在淀粉液态培养基中生产α-淀粉酶

以枯草杆菌(Bacillus subtilis BF7658)为实验菌株,以淀粉为主要原料,采用液态培养基发酵, 生产α-淀粉酶.结果表明:在23℃至44℃内,培养基起始pH值为自然pH值,产酶最佳培养温度为37℃; 枯草杆菌在淀粉液态培养基中控制温度为37℃,振荡培养,其产酶最适宜淀粉与水组成比例为:75 : 100; 在最佳温度37℃下,淀粉:水为75:100时,最佳培养时间为36h.