U-Pb定年锆石标准~(176)Hf/~(177)Hf比值的多接收器电感耦合等离子体质谱测定

利用MicromassIsoprobe型多接收器电感耦合等离子体质谱(MCICPMS)测定UPb定年国际锆石标准91500、Temora和本实验室锆石工作标准样We1的176Hf/177Hf比值。对添加Zr的室内Hf标准溶液HfGIG的模拟实验表明:Zr/Hf≤120时,Zr对Isoprobe型MCICPMS的Hf同位素比值测定值没有明显的影响,所以锆石Hf分离纯化流程采用改进的高温高压氢氟酸溶解和其后的一个离子交换分离流程实现,整个流程Hf的回收率高于90%。176Hf/177Hf比值测定采用JMC475Hf标准溶液(176Hf/177Hf=0.282160)进行外部校正并监控仪器漂移。标准样91500、Temora和We1平均的176Hf/177Hf比值测定结果分别为(0.282310±0.000034)、(0.282706±0.000020)和(0.281534±0.000009)。上述每个结果包括至少7组独立的锆石样品的溶解、分离和测定,表明标准样91500、Temora和We1是Hf同位素组成均一的。本实验结果对于激光熔蚀多接收器电感耦合等离子体质谱(LAMCICPMS)锆石原位176Hf/177Hf比值测定校正方法的检验具有重要意义。     

3C认证中需要补充的质量管理体系文件

阐述了在3C认证过程中，质量管理体系文件的补充如何既能满足ISO9000标准又能涵盖工厂质量保证能力要求。     

基于生命周期管理的数据存储在BOSS中的应用

随着电信运营商业务的发展,业务运营支撑系统（BOSS）的海量数据存储使系统的复杂性和成本越来越高,系统的性能也越来越难管理。对这一问题,提出了利用数据生命周期的管理理念来进行BOSS系统数据的管理,并在此基础上实现了BOSS中的营业系统数据的生命周期管理。在实现系统数据海量存储需求的同时,节约了系统建设的成本,也提高了系统的性能。     

马克思主义群众观视域下农村基层党组织建设研究

文章基于马克思主义的群众观, 从当前农村基层党组织建设现状出发, 探索出在马克思主义群众观指引下 加强农村基层党组织建设的路径, 为基层党组织的建设发展与构建社会主义新农村提供了借鉴。     

GaAs阴极激活铯源质量对成像器件性能的影响

为了解决三代微光器件研究中出现的阴极灵敏度低、光电发射不均匀、稳定性差等问题,重点开展了铯源质量对阴极性能产生影响的试验研究。结果表明,激活铯源纯度、装配结构、铯源与阴极距离对阴极光电发射灵敏度、均匀性影响最大。铯源出口孔径多少大小及射出方向是阴极产生暗班的主要原因。在铯源材料成分结构与阴极距离确定之后,阴极灵敏度的高低主要决定于对铯源的除气工艺,通过对铯源除气工艺进行优化,制备出了阴极灵敏度大于1700μA/lm三代微光器件。     

Determination of pistachio drying behaviour and conditions in a solar drying system

The main object of this study is to determine the drying behaviour and conditions of shelled and unshelled pistachio samples using both solar assisted and open sun drying. For each drying experiment, 100 g each of unshelled and shelled pistachio were used. The least‐squares method was applied to find the drying curve equation of pistachio. During the experiments, shelf temperatures, weight loss of pistachio, moisture content of air, and distribution of solar radiation were measured; and presented depending on the drying time. Also, the mass shrinkage ratios of shelled and unshelled pistachio samples were determined, and the experimental uncertainty ratio was calculated as 15–16.5 per cent based on the experimental results. It was deduced that the shelled and unshelled pistachio samples in the solar assisted forced convection dryer were perfectly dried at temperatures of 50±10°C in the time period of 6 h. Whereas, the samples in the open sun drying were not sufficiently dried at temperatures of 28±4°C in the same time period. Hence, it is suggested that the pistachio samples with approximately 29.0 per cent of moisture are dried in the solar assisted convection dryer at 50±10°C of temperature in the time period of approximately 6 h in order to protect from the negative climatic and environmental effects. However, it is not desirable to dry the pistachio samples in the open sun because of greater drying time, dirt, dust and harmful insects. Copyright © 2001 John Wiley & Sons, Ltd.     

宝鸡峡塬边渠道高边坡变形破坏分析及削坡设计

土体含水量是影响高边坡稳定的重要因素。本文对宝鸡峡灌区总干98km高边坡变形破坏原因进行了探讨,并提出高边坡治理设计坡型。     

岩坡稳定性三维分析

使用刚体极限平衡法,通过建立分类座标系,导出了由三个结构面和一个临空面组成的四面体岩坡在任意外荷载作用下,结构面上正压力、滑动力的统一表达式。据此,可方便地判别岩坡的滑动类型,进行岩坡滑动分析。本算法较为简洁,能考虑结构面上凝聚力对岩坡滑动的影响。     

METABOLIC RESPONSES OF BAKER'S YEAST TO GLUCOSE ADDITION DURING AEROBIC STARVATION

The kinetics and extent of glucose uptake, ethanol and acetate production, glucose-induced medium acidification and endogenous respiration were studied in baker's yeast starved aerobically for 0, 28, 54 and 96 h in saline (9 g litre^?1 NaCI) at 35°C. Except for the last interval, prolonged starvation brought about an overall increase in most parameters; the transient increase in endogenous respiration observed after glucose addition was lowered with proceeding starvation. A 96 h starvation brought about a change in the kinetics of ethanol production, sharp increase in acetate production and a strong reduction of both the extent and the rate of glucose-induced acidification and of endogenous metabolism.     

反倾岩石边坡变形破坏试验及有限元分析

根据相似理论建立地质力学模型,研究反倾层状边坡岩体的变形破坏机制。介绍了模型试验的设计和过程,研究了原型边坡的变形破坏机制和岩层倾角对边坡稳定性的影响。同时进行了Ansys模拟计算。通过比较这两种研究方法的结果,发现反倾层状边坡岩体的变形机制为倾倒变形,破坏模式为弯折破坏;破坏首先在坡顶产生,边坡变形加速的过程是在开挖结束一段时间后才出现;岩层倾角的变化对反倾边坡的变形影响不敏感,但对边坡变形加速持续时间的长短有较大的影响,岩层倾角越小,变形加速所持续的时间越长。