Water isotope variations in the snow pack and summer precipitation at July 1 Glacier, Qilian Mountains in northwest China

This paper presents the stable isotope data of the snow pack and summer precipitation collected at the July 1 Glacier, Qilian Mountains in northwest China and analyses their relationships with meteorologi- cal factors. On an event scale, there is no temperature effect on the δ 18O values in the summer pre- cipitation, whereas the amount effect is shown to be clear. By tracing the moisture transport history and comparing the precipitation with its isotopic composition, it is shown that this amount effect not only reflects the change in moisture trajectory, which is related to the monsoon activities, but is also associated with the cooling degree of vapor in the cloud, the evaporation of falling raindrops and the isotopic exchange between the falling drops and the atmospheric vapor. As very little precipitation occurs in winter, the snow pack profile mainly represents the precipitation in the other three seasons. There are low precipitation δ 18O ratios in summer and high ratios in spring and autumn. The Meteoric Water Line (MLW) for the summer precipitation is δ D = 7.6 δ 18O 13.3, which is similar to that at Delingha, located in the south rim of the Qilian Mountains. The MWL for the snow pack is δ D = 10.4 δ 18O 41.4, showing a large slope and intercept. The deuterium excess (d) of the snow pack is positively correlated with δ 18O, indicating that both d and δ 18O decrease from spring to summer and increase from early autumn to early spring. This then results in the high slope and intercept of the MWL. Sea- sonal fluctuations of d in the snow pack indicate the change of moisture source and trajectory. During spring and autumn, the moisture originates from continental recycling or rapid evaporation over rela- tively warm water bodies like Black, Caspian and Aral Seas when the dry westerly air masses pass over them, hence very high d values in precipitation are formed. During summer, the monsoon is responsi- ble for the low d values. This indicates that the monsoon can reach the western part of the Qilian Mountains.     

Analysis of Petri net model and task planning heuristic algorithms for product reconfiguration

Reconfiguration planning is recognized as an important factor for reducing the cost of manufacturing reconfigurable products, and the associated main task is to generate a set of optimal or near-optimal reconfiguration sequences using some effect algorithms. A method is developed to generate a Petri net as the reconfiguration tree to represent two-state-transit of product, which solved the representation problem of reconfiguring interfaces replacement. Relating with this method, two heuristic algorithms are proposed to generate task sequences which considering economics to search reconfiguration paths effectively. At last, an objective evaluation is applied to compare these two heuristic algorithms to other ones. The developed reconfiguration task planning heuristic algorithms can generate better strategies and plans for reconfiguration. The research finds are exemplified with struts reconfiguration of reconfigurable parallel kinematics machine （RPKM）.     

Modeling Mixed Traffic Flow at Crosswalks in Micro-Simulations Using Cellular Automata

The cellular automata (CA) micro-simulation model was used to describe the behavior of the mixed traffic flows at crosswalks where the pedestrians compete with the vehicles to cross the roadway. The focus of this paper is the behavior of pedestrians and the influence of pedestrians’ behavior on the vehicle flow, pedestrian flows, and the vehicle waiting time. The proportion of pedestrians who do not obey traffic laws, the group effect, and expected waiting time of pedestrians, regarded as the most important pedestrian characteristics, are taken into consideration in the analysis. Simulation results show the ability of the micro-simulation to capture the most important features of mixed traffic flow.     

杆体可回收锚杆锚固性能分析

塑料锚头、金属可回收杆体，在锚固端能够提供足够大的胀锚力。在完成支护任务后，杆体可回收复用以降低支护材料成本。为了分析其锚固作用，应用ＡＮＳＹＳ软件，对其锚固性能进行了数值计算。分析结果说明，该锚杆具有恒阻让压特性，能够有效支护围岩。     

神经外科手术中动脉与呼气末二氧化碳分压差稳定性的观察

观察神经外科手术过程中动脉和呼气末二氧化碳分压差值（Ｐａ－ＥＴＣＯ２）的稳定性。对３０例幕上肿瘤行择期肿瘤切除术的患者，于硬脑膜打开后，给予安氟醚１．１～１．５ＭＡＣ，将动脉内压维持在每小时１０±０．６７ｋＰａ。分别于麻醉前、气管插管后５ｍｉｎ、开颅后５ｍｉｎ、术中降压１ｈ和术终抽取动脉血行血气分析。对开颅超过３ｈ的１４例患者，则于３ｈ后再抽取１次动脉血样，同时记录呼气末二氧化碳分压（ＰＥＴＣＯ２）。在手术过程中ＰａＣＯ２平均值为４．２１±０．７７ｋＰａ，ＰＥＴＣＯ２平均值为３．８６±０．６６ｋＰａ，Ｐａ－ＥＴＣＯ２平均值为０．３３±０．６６ｋＰａ，ＰａＣＯ２与ＰＥＴＣＯ２显著相关（Ｐ＜０．０１）。ＰａＣＯ２、ＰＥＴＣＯ２和Ｐａ－ＥＴＣＯ２不同时间点之间无显著性差异。如能在麻醉后及早确定Ｐａ－ＣＯ２与ＰＥＴＣＯ２差值，术中监测ＰＥＴＣＯ２仍有一定价值     

气相合成SiC超细微粉的生成研究

本文对激光驱动气相合成超细微粉的反应条件与反应过程的关系作了讨论和分析,探讨了提高生成率的途径。     

郑州市房地产业预警展望及政策建议

阐述了房地产业发展状况及郑州行业背景,对郑州市房地产发展进行了客观、全面的评价,分析了郑州市房地产预警的重要意义,针对存在的一些问题提出了郑州市房地产预警的相关政策建议。     

南村地质灾害分析

通过实际资料，详细论述了南村的地质灾害现状，初步分析了南村地质灾害的形成机理，并讨论了校区地质灾害应采取的防治对策。     

粮食流通体制改革与收购资金封闭运行

农业问题和粮食问题既是改革的起点，又是改革的重点和难点，新时期流通体制改革和购销工作的重中之重是：敞开收购农民余粮，顺价销售，收购资金封闭运行，即所谓“三项政策，一项改革”。文章就这三项政策的内部关系，结合农发行工作实际，对实现收购资金封闭运行提出一些见解及构想。