173Lu和174gLu衰变数据的测量

175Lu（n;2n）174m,gLu（n;2n）173Lu反应在高能中子通量监测中具有重要作用,其产物的放射性活度通常用HPGe探测器测量,这就需要174m,gLu和173Lu的半衰期和γ射线发射率等衰变数据必须准确无误。在主要的评价核数据库中,只有ENDF/B 7.1和JEFF 3.1.1数据库给出了173Lu和174Lu的半衰期和γ射线的发射几率等衰变数据,其中173Lu的射线发射几率ENDF/B 7.1库比JEFF 3.1.1库总体偏高,其他评价数据两个数据库非常一致。在中国原子能研究院的串列加速器上用20 MeV质子辐照金属Yb靶生产了含有173Lu,174m,gLu的放射性溶液,用激光共振电离质谱（LRIMS）和热表面电离质谱（TIMS）两种同位素稀释法测定了该溶液中173Lu和174m,gLu核素浓度,然后制备测量源在HPGe探测器上进行了近7年的跟踪测量,发现173Lu的半衰期为1.45 a,比目前评价的数据1.37 a高6.1%,636.1 keV射线发射几率的偏差最大,比ENDF/B 7.1的评价数据偏高7%。174gLu半衰期的测量结果3.37 a175Lu（n;2n）174m,gLu（n;2n）173Lu反应在高能中子通量监测中具有重要作用,其产物的放射性活度通常用HPGe探测器测量,这就需要174m,gLu和173Lu的半衰期和γ射线发射率等衰变数据必须准确无误。在主要的评价核数据库中,只有ENDF/B 7.1和JEFF 3.1.1数据库给出了173Lu和174Lu的半衰期和射线的发射几率等衰变数据,其中173Lu的射线发射几率ENDF/B 7.1库比JEFF 3.1.1库总体偏高,其他评价数据两个数据库非常一致。在中国原子能研究院的串列加速器上用20 MeV质子辐照金属Yb靶生产了含有173Lu,174m,gLu的放射性溶液,用激光共振电离质谱（LRIMS）和热表面电离质谱（TIMS）两种同位素稀释法测定了该溶液中173Lu和174m,gLu核素浓度,然后制备测量源在HPGe探测器上进行了近7年的跟踪测量,发现173Lu的半衰期为1.45 a,比目前评价的数据1.37 a高6.1%,636.1 keV γ射线发射几率的偏差最大,比ENDF/B 7.1的评价数据偏高7%。174gLu半衰期的测量结果3.37 a,比评价数据3.31 a高约1.8%,174gLu 76.5 keV和1 241.8 keV γ射线的发射几率比ENDF/B 7.1的评价数据分别低1.87%和12.8%。175Lu(n,2n)174m,gLu(n,2n)173Lu are important neutron reactions to monitor the high energy neutron fluxes and the residual nuclei, 174m,gLu and 173Lu, are usually measured by a HPGe spectrometer conveniently so that the decay data such as half lives and gamma-ray emission probabilities of 174m,gLu and 173Lu must be accurate. There are evaluated decay data only in ENDF/B 7.1 and JEFF 3.1.1 among the major evaluated nuclear data libraries, where the most data are almost same besides the gamma-ray emission probabilities of 173Lu are higher in ENDF/B 7.1 than that in JEFF 3.1.1. Yb metal as a target was irradiated by 20 MeV proton beams on a tandem accelerator in CIAE to produce 174m,gLu and 173Lu, and 176Lu isotopic dilution methods based upon a laser resonance ionization mass spectrometer (LRIMS) and a thermal surface ionization mass spectrometer (TIMS) were employed to determine the numbers of nuclides of 174Lu and 173Lu in a solution containing the irradiated target. Several radioactive sources made from the solution had been measured by a HPGe detector during the past 7 years and the peak intensities of the characteristic gamma-rays from 174gLu and 173Lu were analyzed to determine the half lives and gamma-ray emission probabilities. According to the measurements, the half life of 173Lu is 1.45 a, which is about 6.1% longer than the evaluated 1.37 a, and the gamma-ray emission probabilities of 173Lu is also different from the evaluated data, especially the emission probability of 636.1 keV gamma-ray of 173Lu is 7% higher than the value in ENDF/B 7.1. The half life of 174gLu is 3.37 a, about 1.8% longer than the evaluated 3.31 a, and the emission probabilities of 76.5 keV and 1 241.8 keV gamma-rays of 174Lu are 1.87% and 12.8% lower than the evaluated data in ENDF/B 7.1, respectively.     

带光纤环的分布式光纤拉曼温度系统

 为了抑制分布式光纤拉曼温度系统的温漂和瑞利散射光窜扰反斯托克斯散射光,在传感光纤前端盲区后放置光纤取样环,用瑞利散射光解调反斯托克斯散射光及用光纤取样环的温度计算光纤线上其它点的温度,提高了系统的测温精度和稳定性。采用功率100 mW,波长1.55 μm,脉宽10 ns脉冲激光器和15 dB前置光纤放大器,100M14bitA/D转换卡及DSP作数字平均构建光纤拉曼温度系统的实验,实现了测温误差在±0.03 ℃内。     

FTIR-ATR技术考察TiO2膜对油酸的光催化氧化性能

采用Sol-Gel和PVD法在玻璃、陶瓷、铝片表面制备出TiO2膜,直接将食用油中的主成分油酸用溶剂稀释后均匀涂在膜表面,采用FTIR-ATR技术实现了对膜样品光催化自清洁性能的快速准确评价,并通过测量水的接触角评价了膜的亲水性。结果表明,Sol-Gel法和PVD法制备的TiO2/玻璃膜都具有较好的光致亲水性和光催化降解油酸性能,两者的亲水性没有明显差别,但前者的光催化活性稍优于后者。比较Sol-Gel法制备的TiO2/玻璃、TiO2/陶瓷和TiO2/铝片膜对油酸的光催化降解性能发现,光照3·5h后3个样品的降解率分别为92%,85%和46%,表明基底材料性质对TiO2膜的光催化活性有明显影响,镀在非导电性玻璃和陶瓷表面的TiO2膜比镀在导电性金属铝表面的TiO2膜对油酸有更高的光催化降解能力。     

常压MOCVD生长Ga2O3薄膜及其分析

以去离子水(H₂O)和三甲基镓(TMGa)为源材料,用常压MOCVD方法在蓝宝石(0001)面上生长出β-Ga₂O₃薄膜.用原子力显微镜(AFM)、X射线衍射(XRD)以及二次离子质谱(SIMS)实验表征Ga₂O₃外延膜的质量.在X射线衍射谱中有一个强的Ga₂O₃(102)面衍射峰,其半峰全宽(FWHM)为0.25°,表明该Ga₂O₃外延膜是(102)择优取向.在二次离子质谱中除了C、H、O和Ga原子外,没有观测到其他原子.     

等离子体断路开关和电感负载间的功率流特性

利用PIC (particle-in-cell) 方法,结合实验装置的几何结构和实验结果,采用动态开关模型,对微秒等离子体断路开关和电感负载间的功率流特性进行了研究。模拟得到了与实验结果符合较好的开关电压和负载电流波形,并给出了开关下游出现的稀薄等离子体的密度(约1012 cm-3)和速度(约1 cm/ns), 同时也得到了开关下游的空间电流分布。模拟结果表明,开关下游的结构应避免阻抗突变以减少电流损失,同时提高开关阻抗可有利于提高负载上的最大功率。     

ICP-AES测定氟化稀土中铝

采用高氯酸、盐酸分解样品,草酸将稀土沉淀分离,用ICP-AES快速测定氟化稀土中的铝,加标回收率达98%—102%,相对标准偏差＆lt;2.0%,此方法分析简单快速、结果准确可靠。     

A Diode-Pumped 1617 nm Single Longitudinal Mode Er：YAG Laser with Intra-Cavity Etalons

We demonstrate the continuous wave p-polarized single longitudinal mode （SLM） operation of an Er：YAG laser at 1617.6nm pumped by a diode-laser with three inserted Fabry-Perot （FP） etalons at room temperature. The Brewster angle inserted FP is applied to obtain the p-polarized laser. For free running, the maximum output power is 570 m W with a pump power of 12.5 W. An incident pump power of 12.5 W is used to generate the maximum p-polarized single longitudinal mode output power of 78.5 m W, corresponding to a slope efficiency of 1.6% and an optical-to-optical efficiency of 0.61%. The beam quality M2 is measured to be 1.15 at the highest SLM output power. This stable polarized SLM oscillation is encouraging due to its application for an injection-locked system used as a master laser.     

Simulation of Dual Frequency Capacitive Sheath over a Concave Electrode in Low Pressure

A self-consistent two-dimensional （2D） collisionless fluid model is developed to simulate the characteristics of a dual frequency capacitive sheath over an electrode with a cylindrical hole. The model consists of 2D time-dependent fluid equations coupled with Poisson＇s equation, in which the low-frequency （LF） and high-frequency current sources are applied to an electrode. Thus, the so-called equivalent circuit model coupling with the fluid equations will be able to self-consistently determine the relationship between the instantaneous voltage on the powered electrode and the sheath thickness. The time-averaged potential, electric field, ion density in the sheath and ion energy distributions at the bottom of the hole are calculated and compared for different LF frequencies. The results show that the LF frequency is crucial for determining the sheath structure. The existence of the cylindrical hole on the electrode obviously affects the sheath profile in the parallel to the electrode and makes the sheath profile tend to adapt the contours of the electrode, which is the plasma molding effect.     

Study of Ternary Fission Produced in 12C Bombarding 209Bi Target with Medium Energy

Alternative layers of target material,which were prepared by evaporating ²⁰⁹Bi on the surface of mica foils,were irradiated with ¹²C ions.Ternary fission events in which three fragments of comparable mass were produced in 2525－47.5MeV/A ¹²C+²⁰⁹Bi reaction,were recorded by the mica detectors with 2π geometry.The observed probability ratio of ternary fission relative to binary fission in 2π geometry was modified to 4π geometry spatial in terms of the Monte Carlo method.The values of ratioes increase with the bombarding energy,and are compared with the calculation result of the cascade fission model.     

HPLC测定辛芩喷雾剂中的黄芩苷

建立HPLC测定辛芩喷雾剂中黄芩苷含量的方法.采用Hypersil C18 (4.6mm×150mm,5μm)为色谱柱,流动相为甲醇∶水∶磷酸(47∶53∶0.2,V/V/V),流速为1.0mL/min,紫外检测波长为280nm.在6.0-300μg·mL-1范围内线性关系良好(r=0.9993).加标回收率为97.02％,重复性实验的RSD为1.08％(n=3).本法操作简便、快速准确,重现性好,可作为该制剂的含量测定方法.