Temperature variations on the Tibetan Plateau over the last two millennia

The paleoclimate data recovered from ice cores,tree rings and lake sediments indicate regional features of cfimatic change on the Tibeta n Plateau (TP) during the last 2000 years. The composite temperature reconstructions in-dicate that several main climatic episodes, such as the “LittleIce Age“ between 1400 and 1900, the “Medieval Warm Pe-riod“ in 1150-1400, a less warm period in 800-1100, and an earlier cold period between the 3rd and 5th centuries,occurred in the TP. In addition, temperature varied from region to region. The period from AD 800 to 1100, which waswarm in northeastern TP, was contemporaneous with cool-ing in the western and southern TP. The southern TP ex-perienced warming between 1150 and 1400. For western TP,the δ^18O records of the Guliya ice core indicate that the pe-Hod 1250-1500 witnessed a clear warming. Large-scaletrends in the temperature history from northeastern TP aremore similar to those in eastern China than are the trendsfrom the Guliya ice cap far to the west and southern TP. The most prominent similarities between the temperature varia-tions of the TP and eastern China are such cold phases as 1100-1150, 1500-1550, 1650-1700 and 1800-1850, andthe latter three cold events match with three widespreadg lacial advances which occurred on the TP during the Little Ice A2e.     

Time-division phase modulated single-photon interference in a Sagnac interferometer

We introduce a stable, long-distance singlephoton Sagnac interferometer, which has a balanced configuration to efficiently compensate phase drift caused by change of the fiber-optic path. By using time-division phase modulation, single-photon interference was realized at 1550nm in a 5-km-long as well as 27-km-long Sagnac fiber loops,with a fringe visibility higher than 90% and long-term stability. The stable performance of the single-photon interference indicated that the time-division phase-modulated Sagnac interferometer might readily lead to practical applications in single-photon routing and quantum cryptography.     

Expression of human clotting factor Ⅸ mediated by recom- binant lentiviral vector in cultured cells and hemophilia B mice

To explore the expression of human clotting factor Ⅸ (hFⅨ) cDNA in vitro and the feasibility of gene therapy for hemophilia B mice mediated by recombinant lentiviral vector, a recombinant hFⅨ lentiviral vector driven by ubiquitin-C promoter, FUXW, and by ABP liver specific promoter, FAXW, was constructed respectively. Recombinant lentivirus was harvested from 293T cells by calcium phosphate-mediated transient cotransfection of three plasmids (transgene vector, CMV腞8.2, VSV-G). hFⅨ expression was detected in supernatant of 293T, BHK and L-02 cells infected with FUXW virus, whereas higher expression of hFⅨ levels (630 ng/106 cells/48 h) was detected only in L-02 cells infected with FAXW virus. Serum hFⅨ antigen was detected in all hemophilia B mice treated with FAXW virus by tail vein injection, an efficiency level of hFⅨ was observed (45 ng/mL, approximately 1% of normal human levels), the expression lasted for more than 60 d. The results indicated that HIV-based lentiviral vectors offer a promising approach to the gene therapy of hemophilia B.     

基于直接变量反馈控制混沌

变量反馈控制混沌的基础上，提出了一种不需要知道目标轨道的直接变量反馈控制混沌的方法，通过调节反馈强度可以得到不同的稳定周期轨道，这种方法用于控制混沌的Duffing方程，得到了满意的结果。     

NO2分子Faraday效应磁强计

采用Faraday光谱方法,系统研究了交流(Zeeman调制)、直流(光强调制)磁场下,NO2气体分子的光谱信号随外加磁场的变化关系.实验结果与理论分析表明,NO2分子的光谱信号与外加磁场呈线性关系,由此提出了一种NO2分子Faraday效应磁强计,预期可以测量5×10-3～100 mT,DC-1 MHz范围内的磁场,并具有良好的线性度.     

块三对角矩阵方程的追赶法及其应用

导出了块三对角矩阵方程追赶法的一套递推关系式，并编制出相应的计算机Ｃｏｄｅ。该Ｃｏｄｅ具有良好的实用价值，可供在实际问题中使用。     

用回转变换张量法求解FANUC S—5机器人的运动学问题

本文就一台六轴通用机器人ＦＡＮＵＣ Ｓ－５，建立了它的运动学模型，利用回转变换张量法求解出运动学正逆问题的封闭式解。在求解逆问题的过程中，根据ＦＡＮＵＣ Ｓ－５的结构特点分析了其可能的所有解，从而为机器人的运动空间分析、轨迹规划以及在此基础上开发应用系统提供了运动学理论依据。     

串级前馈式极点配置自校正PID控制器

对传统的数字PID结构进行了改进，增加了对给定值的滤波作用，同时考虑了串级控制方案，使极点配置自校正技术处理复杂工况（外扰、时滞、非最小相位、开环不稳）的能力有了较大的提高，仿真结果表明了所给控制器的有效性     

滑动轴承无摩擦接触参数的边界元分析

应用边界单元法（ＢＥＭ），对平面应变情况下滑动轴承无摩擦接触时的接触参数进行了分析计算，并与常规Ｈｅｒｔｚ公式计算结果进行了对比。结果表明，用边界单元法可以提高接触参数的计算精度，并妥善解决了Ｈｅｒｔｚ公式计算值偏低的问题。另外在分析了轴承系统尺寸、材料参数及载荷变化因素而进行相应计算的基础上，给出了滑动轴承接触参数计算的经验公式。