Do multiple cycles of aeolian deposit-pedogenesis exist in the reticulate red clay sections in southern China?

Since the Quaternary scientists successfully dis-closed the paleoclimatic significance of the loess-paleo- sol sequence in the Loess Plateau, Northwest China, the loess-paleosol sequence has become well-known terres-trial materials revealing the multiple cyclic changes of Quaternary climates. As a carrier of paleoenvironmental information, it could compare beauty with the deep ocean deposit[8]. In recent years, however, the researchers began to put their sights to southern China. They try t…     

The age of formation of the mirabilite and sand wedges in the Hexi Corridor and their paleoclimatic interpretation

The Hexi Corridor is located at the transition zone of the Asian summer monsoon and westerly airflow, and lies in an important position in terms of its ecological fragility and climatic sensitivity. During a recent field expedition to this region, we found a sedimentary mirabilite layer in a number of localities including Suwushan, Yanchi, Baitujing, Yanchi Gaotai, Huahai, Yumen, Halanuo扙r, and Dunhuang (Fig. 1), which have the potential to provide important information about environmenta…     

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.     

应用于加速器驱动次临界系统的程序开发

开发了应用输运理论方法的两套程序系统：蒙特卡罗－燃耗程序系统和输运－燃耗程序系统。针对蒙特卡罗程序不能计算燃料的同位素成分变化，提出将它和燃耗计算程序耦合以完成燃耗计算。燃耗程序所使用的单群截面由蒙特卡罗程序计算。将用于常规反应堆的计算方法和策略推广到输运－燃耗程序系统，这使得计算步序大大简化，并改进了精度。对加速器驱动次临界系统的基准题进行了校核计算，其结果和其他国家的计算结果符合良好，这表明所提出的计算方法与程序系统是成功的。     

热工类专业课教学探讨

文章对热工类专业课教学作了初浅的探讨，并从不同的侧面对教学方法进行了讨论。     

离子通道特性研究

简述了在等离子体加载高功率微波器件中的离子通道的研究背景及物理机制，利用电磁场理论导出了离子通道的聚束条件和通道半径的表达式，并对各区域的相对介电常数作了分析。     

泵送混凝土施工技术

介绍了目前普遍采用的混凝土泵及其工作原理，阐述了泵送混凝土工艺、质量控制及混凝土泵送施工组织。     

有限差分法地震波走时计算

改进文献「１」提出的有限差分计算走时的算法，射线路径也可根据互易性原理求出，模型计算表明该方法精度较高并适用于速度较差较大的情形。该算法对层析成像，迭前Ｋｉｒｃｈｈｏｆｆ偏移将是非常有用的。