原子吸收光谱法测定冬凌草中的矿物元素

用原子吸收光谱法测定冬凌草中影响人体健康的8种矿物元素Cu、Zn、Fe、Mn、Ca、Mg、Se和Pb的含量。样品经硝酸-高氯酸消解后,采用偏振塞曼效应扣除背景吸收,用火焰原子吸收光谱法检测积分吸收测定冬凌草中Cu、Zn、Fe、Mn、Ca和Mg的含量,用石墨炉程序升温原子吸收光谱法检测峰值吸收测定Se和Pb含量。测定结果显示:该方法的精密度RSD为1.22%—5.64%;加标回收率为95.0%—110.5%;8种矿物元素的检出限(P=95%,α=0.5)分别为Cu0.034、Zn0.0028、Fe0.031、Mn0.110、Ca0.367、Mg0.132mg·mL-1,Pb1.40μg.L-1和Se1.86μg.L-1。该方法简便快速、灵敏、准确,适用于中药冬凌草中矿物元素含量的测定。     

Generation of femtosecond laser pulses at 263 nm by K_3B_6O_(10)Cl crystal

The third harmonic generation(THG) of a linear cavity Ti:sapphire regenerative amplifier by use of a K_3B_6O_(10)Cl(KBOC) crystal is studied for the first time. Output power up to 5.9 mW is obtained at a central wavelength of 263 nm,corresponding to a conversion efficiency of 4.5% to the second harmonic power. Our results show a tremendous potential for nonlinear frequency conversion into the deep ultraviolet range with the new crystal and the output laser power can be further improved.     

Tunable ground-state solitons in spin–orbit coupling Bose–Einstein condensates in the presence of optical lattices

Properties of the ground-state solitons, which exist in the spin–orbit coupling(SOC) Bose–Einstein condensates(BEC) in the presence of optical lattices, are presented. Results show that several system parameters, such as SOC strength,lattice depth, and lattice frequency, have important influences on properties of ground state solitons in SOC BEC. By controlling these parameters, structure and spin polarization of the ground-state solitons can be effectively tuned, so manipulation of atoms may be realized.     

Generation of femtosecond laser pulses at 396 nm in K_3B_6O_(10)Cl crystal

K_3B_6O_(10)Cl(KBOC), a new nonlinear optical crystal, shows potential advantages for the generation of deep ultraviolet(UV) light compared with other borate crystals. In this paper we study for the first time the second harmonic generation(SHG) of a femtosecond Ti:sapphire amplifier with this crystal. Laser power is obtained to be as high as 220 m W at the central wavelength of 396 nm with a 1-mm-long crystal, and the maximum SHG conversion efficiency reaches 39.3%. The typical pulse duration is 83 fs. The results show that second harmonic(SH) conversion efficiency has the room to be further improved and that the new nonlinear crystal is very suited to generate the high efficiency deep ultraviolet laser radiation below 266 nm.     

原子吸收光谱法测定硫酸硫脲溶液中的金

以稀王水金溶液作为标准溶液,原子吸收光谱法可以直接测定硫酸流脲溶液里的金。线性范围0.2×10~6～12×10~(-6),相对标准偏差(RSD)<5％。硫脲使金的吸光度减少,硫酸使金的吸光度增加,经过空白曲线修正后可用作实际样品的分析,简化分析步骤。     

Pb(Ⅱ)-SXO-CTMAB-Span80 吸光光度法测定微量铅(Ⅱ)

本文研究了 Pb( ) - SXO- CTMAB- Span80体系的显色反应。该反应快速、灵敏、稳定。表观摩尔吸光系数 ε56 0 =3.36× 10 4 L· mol- 1· cm- 1 ,铅含量在 0— 4 0 μg/ 2 5 m L 范围内符合比耳定律 ,方法已用于测定树叶上附着铅含量     

实用化少模光纤的研究

针对大容量光纤通信系统,设计了一种实用化的椭圆纯硅芯少模光纤,给出了光纤的设计原理与参考标准,运用全矢量有限元法结合完美匹配层边界条件分析了光纤的传输特性.在1.4~1.65μm波长处,光纤处于稳定的HE_(11)和HE_(21)双模运转,模式有效折射率差大于1.8×10~(-3),避免了模间耦合和串扰;在工作波长1.55μm处,HE_(11)和HE_(21)模的色散系数分别为19.61和4.41ps/(nm·km),色散斜率分别为0.048和0.002ps/(nm~2·km),模场面积分别为97.17和143.96μm2,模式的衰减系数均小于0.21dB/km.该光纤的传输特性基本符合G.652和G.655光纤标准,可利用现有成熟的"预制棒拉丝工艺"制备,同时与波分复用技术相结合可以成倍提升光网络的传输容量,对于下一代通信网络带宽的提升具有重要意义.     

变质量二体问题及其解

该文采用Ｇｙｌｄｅｎ－Ｍｅｓｈｃｈｅｒｓｋｉｉ方程和Ｅｄｄｉｎｇｔｏｎ－Ｊｅａｎｓ定律研究了变质量二体问题并得到对于任意足值的Ｇ－Ｍ型变质量二体问题的解。结果表明由于主星的质量损失会使伴星的轨道半长径α产生一阶长期和周期项，轨道偏心率ｅ产生一阶周期和二阶混合项，近星点角角距ω产生一阶周期、二阶长期和混合项。文末，还对所得的结果进行了讨论。     

Preliminary Study on Anti-Dropping Methods for Short Cashmere Woolen Cloth

The fibre dropping mechanism of short cashmere fabrics is elucidated. Results show that to reduce the fibre dropping, it is necessary to increase the linkage force among the fibers, and the special anti - dropping finishing for the fabrics which have been normally finished, should be carried out. To evaluate the six selected anti - dropping finishing agents, fuzzy judgment method was used, and the agent, with the most effect on anti - dropping, was found out.