R相C60聚合物的磁性研究

在高温高压条件下利用高压合成装置合成了二维R相C60聚合物,并利用X射线衍射(XRD)和超量子干涉(SQUID)对合成的样品进行了研究.X射线衍射(XRD)数据表明,在6 Gpa压力和7000C-7250C的温度条件下合成的聚合物为纯度较高的二维R相C60聚合物,当温度升高至8000C时,富勒烯的笼状结构塌陷,样品全部变为无定形碳结构.超量子干涉(SQUID))数据表明,在富勒烯笼状结构出现破缺或共价键结构出现断裂的边界条件下制备的二维R相C60聚合物具有铁磁性,样品的磁性来源于破缺的C60分子笼和断裂的共价键.     

Charge state effect on the K-shell ionization of iron by xenon ions near the Bohr velocity

Fe K-shell ionization cross sections induced by 2.4–6.0 MeV Xe20+are measured and compared with different binaryencounter-approximation(BEA)models.The results indicate that the BEA model corrected both by the Coulomb repulsion and by the effective nuclear charge(Zeff)agrees well with the experimental data.Comparison of Fe K-shell X-ray emission induced by 5 MeV xenon ions with different initial charge states(20+,22+,26+,30+)verifies the applicability of the effective nuclear charge(Zeff)correction for the BEA model.It is found that Zeffcorrection is reasonable to describe direct ionization induced by xenon ions with no initial M-shell vacancies.However,when the M shell is opened,the Zeffcorrected BEA model is unable to explain the inner-shell ionization,and the electron transfer by molecular-orbital promotion should be considered.     

非晶氧化钛薄膜形成过程中钛离子能量对表面结构影响的机理

研究了非晶氧化钛薄膜沉积过程中入射钛离子能量对表面结构形成机理以及薄膜特性的影响.模拟结果表明,通过提高入射钛离子能量,可以有效降低成膜表面粗糙度,从而减小薄膜表面的光学散射损耗.研究发现,当入射离子能量提高后,薄膜生长模式从"岛"状生长过渡到了"层"状生长,且离子入射点附近的平均扩散系数也有显著增加,这有利于形成更加平整的高质量薄膜表面.     

Temperature-calibrated fiber-optic refractometer based on acompact FBG-SMS structure

A novel all-fiber temperature-calibrated refractometer based on a compact fiber Bragg grating(FBG) single-multi-single(SMS)structure is proposed and experimentally demonstrated.The sensor head is composed of a FBG combined with a SMS structure,in which the middle multimode fiber(MMF)section is etched by a time-controlled hydrofluoric.The transmission dip of SMS is extremely sensitive to ambient refractive index(RI)variation,whereas the upstream FBG provides the necessary temperature information for RI calibration.All aforementioned functions are performed via a compact FBG-SMS structure not longer than 25 mm.The proposed sensing device provides a linear RI sensitivity over water or waterbased solutions(RI values near 1.33 at optical wavelengths for most biological and many environmental applications),and has temperature-calibration capability.Hence,the said refractometer is a good candidate for sensing in chemical and biological applications.     

光子四维量子态隐形传输

多维量子纠缠态比二维纠缠态可加载更多的信息,多维量子系统是量子信息处理中一个很重要的资源.本文采用已实现的光子四维纠缠态,给出了光子四维量子态的张量表达式,并描述了四维量子态隐形传输的一般表示方法;通过讨论光子四维量子态系统的量子通道参数矩阵和测量矩阵的特性,得到实现完全传输和非零概率传输的充要条件.最后,本文给出在多种量子通道下的四维态的量子隐形传态方案,这一过程在张量分析表示下十分清晰明了.     

In situ observation of NaBi(WO4)2 dendrite growth and the study on microstructure of solidification

The dendrite growth process of transparent NaBi(WO4)2 with small prandtl and high melting point was studied by using the in-situ observation system. According to the dynamic images and detailed information, there are two kinds of restriction effect on the dendrite growth, the competition between arms and branches and the convection in the melt. The dendrite growth rate was time dependent, and the rate of arm growth reached the maximum 5.8 mm/s in the diffusive-advective region and rapidly decreased in the diffusive-convective region. The growth rate of branch had the same change trends as the arm's. Based on the EPMA-EDS data of solidification structure of quenched NaBi(WO4)2 melt, it was found that there were component differences from stoichiometric concentration in the melt near the interface during the growth process.     

Single-transverse-mode output from a fiber laser based on multimode interference

An alternative original approach to achieve single-transverse-mode laser emissions from multimode (MM) active fibers is demonstrated. The fiber cavity is constructed by simply splicing a conventional passive single-mode fiber (SMF-28) onto a few centimeters-long active MM fiber section whose length is precisely controlled. Owing to the self-imaging property of multimode interference (MMI) in the MM fiber, diffraction-limited laser output is obtained from the end of the SMF-28, and the MMI fiber laser is nearly as efficient as the corresponding MM fiber laser. Moreover, because of the spectral filtering effect during in-phase MMI, the bandwidth of the MMI fiber laser is below 0.5 nm.     

RP-HPLC测定罗勒中石吊兰素的含量

建立反相-高效液相色谱法(RP-HPLC)测定罗勒(Ocimum basilicumL.)中石吊兰素的含量。用Microsorb-M V 100-5C18(4.6mm×250mm,5μm)色谱柱,甲醇:1%醋酸=86:14(V/V)为流动相,流速为0.5mL/min,检测波长为335nm。石吊兰素浓度在0.27—32.4μg/mL范围内与峰面积线性关系良好(r=0.9999),方法平均回收率大于99%(n=9)。方法简单、可靠,可应用于罗勒植物中石吊兰素的含量测定。     

Performance of La2O3/InAlN/GaN metal—oxide—semiconductor high electron mobility transistors

We report on the performance of La2O3/InAlN/GaN metal-oxide-semiconductor high electron mobility transistors(MOSHEMTs) and InAlN/GaN high electron mobility transistors(HEMTs).The MOSHEMT presents a maximum drain current of 961 mA/mm at Vgs = 4 V and a maximum transconductance of 130 mS/mm compared with 710 mA/mm at Vgs = 1 V and 131 mS/mm for the HEMT device,while the gate leakage current in the reverse direction could be reduced by four orders of magnitude.Compared with the HEMT device of a similar geometry,MOSHEMT presents a large gate voltage swing and negligible current collapse.     

关于《SZJ－10型沼泽检波器》主要技术指标的测试

作者受厂家委托，对美国制造的《ＳＺＪ－１０型沼泽检波器》的主要部件——《振荡探头》进行了有关技术参数的测试，测试结果基本符合实际，为生产厂家提供了测试方法和基本数据．本文《振荡钻探头》两个主要静态参数的测试方法做简单介绍。