考虑参数简化的修正邓肯-张模型

邓肯-张非线性弹性模型被广泛应用于计算围堰修筑、土石坝等水利工程中粗粒土的应力-应变关系。然而,邓肯-张模型参数相对较多、计算结果往往不能充分体现土的剪胀特性。为解决上述缺陷,以邓肯-张模型为基础,提出了参数形式更为简化的应力-应变表达式,并基于沈珠江模型采用二次抛物线形式对应变进行描述,同时对该模型参数形式进行了改进,建立了反映土体体应变-轴向应变关系的体积比表达式。最后通过采用粗粒土和黏性土的试验结果对改进模型进行验证。结果表明：理论计算结果与试验结果吻合较好,改进的模型能够更好地反映土的体应变特征和应力-应变关系,为实际工程中土体的应力-应变关系计算提供了参考。     

青海高原春小麦籽粒蛋白质积累规律研究

分析了阿勃,青春５３３,青农４６９、青农４５２等四个春小麦品种（品系）在青海西宁地区籽粒蛋白质相对含量的变化规律和蛋白质绝对含量的积累进程,结果表明,从开花至成熟,籽粒蛋白质相对含量的变化呈“Ｕ”型曲线,并以花后籽粒发育初期含量最花,花后３１天左右是该地区春小麦籽粒中蛋白质相对含量最低的时期。不同品种在花后不同时期蛋白质相对含量各不相同;籽粒蛋白质绝对含量的积累过程呈“Ｓ”形曲线,可用概率转换方程     

兴安柴胡化学成份研究Ⅲ

本文报道在兴安柴胡中分得10种化合物,经光谱分析和化学方法鉴定为柴胡皂甙 a(Ⅰ)、柴胡皂甙 b_2(Ⅱ),α一菠甾醇-3-0-β-D-葡萄糖甙(Ⅲ)单棕榈酸甘油酯(Ⅳ)、单亚油酸甘油酯(Ⅴ)、二亚油酸甘油酯(1,3)(Ⅵ),二亚油酸甘油酯(1,2)(Ⅶ),α-菠甾醇(Ⅶ),β-谷甾醇(Ⅸ).α-D-葡萄糖(X).     

Bottom Factors Applied to the Zoning Study of the Risk Levels of Landslides in the Three Gorges Reservoir Area

Without taking inducing factors into consideration, this paper adopts a quantitative analysis of the bottom factors in the Three Gorges Reservoir area, studies the relationship between the bottom factors and the development of landslides, and then zones the area according to risk levels. The bottom factors adopted in this paper include lithological characters（U1 ）, gradient（U2 ）, slope form （U3）, difference of helght（U4 ）, and slope orientation（U5 ）. In 4 650 km^2 of the studied area, the areas of the very high, high, medium and low hazard degree area respectively were 57. 94 km^2 , 2 305.15 km^2, 1 241.6 km^2, 1 045.31 km^2. The methodological steps are （1） inversion statistic analysis, （2） the analysis of contribution ratio and weighing, （3） getting results via fuzzy evaluation of risk levels.     

H2、O2与Pd反应的平衡压力研究

基于电子与核振动近似方法,应用密度泛函B3P86方法和相对论有效核势SDD计算,结合统计热力学方法, 研究了100K～1000K温度范围内Pd与H2、O2反应的标准生成热力学函数以及反应平衡压力与温度的关系. 结果表明：Pd与H2、O2反应是放热反应,Pd原子吸附H2的放热量大于吸附O2的放热量,温度升高不利于吸附反应进行;Pd对O2的自发吸附温度很低,室温下几乎不能进行,而对H2的自发吸附温度可高达500K以上;在100K~284.394K可自发吸附O2和H2的温度范围内,O2的反应平衡压力比H2的平衡压力高出9~18个数量级. 因此,O2作为杂质气体对目标反应Pd-H2的影响非常有限.     

利用发光细菌快速测定农药的研究

本文报导了部分农药和除草剂对明亮发光杆菌(Photobacterium phosphoreum)A_2的影响。这些化学物质最低抑制细菌发光的极限浓度分别是:Goal,0.1ppm;灭草特,1.0ppm;以及其他物质都在5.0～10.0ppm左右。因而用发光细菌作指示生物测定部分农药和除草剂的浓度是一种简便,快速、灵敏的方法。     

三种估计疲劳极限方法的比较

文中阐述了3种估计疲劳极限的方法,即加权平均法、按正态分布(或对数正态分布)估计疲劳极限应力值和三参数威布尔分布理论。并对3种方法进行了比较。相比之下三参数威布尔分布理论可求出任意可靠度下的疲劳极限,应用更广泛。     

一种含稀土锰钢的热处理和低温韧性研究

本文研究了加稀土5％Mn钢的热处理、组织和机械性能,探索其部分代替9Ni钢使用于-196℃的可能性,并以同样成分的无稀土钢作为对比,研究稀土在该钢中的作用。     

Synthesis, properties, and optical applications of noble metal nanoparticle-biomolecule conjugates

Noble metal nanoparticles, such as gold or silver nanoparticles and nanorods, exhibit unique photonic, electronic and catalytic properties. Functionalization of noble metal nanoparticles with biomolecules (e.g., protein and DNA) produces systems that possess numerous applications in catalysis, delivery, therapy, imaging, sensing, constructing nanostructures and controlling the structure of biomolecules. In this paper, the recent development of noble metal nanoparticle-biomolecule conjugates is reviewed from the following three aspects: (1) synthesis of noble metal nanoparticle-biomolecule systems by electrostatic adsorption, direct chemisorption of thiol derivatives, covalent binding through bifunctional linkers and specific affinity interactions; (2) the photonic properties and bioactivation of noble metal nanoparticle-biomolecule conjugates; and (3) the optical applications of such systems in biosensors, and medical imaging, diagnosis, and therapy. The conjugation of Au and Ag nanoparticles with biomolecules and the most recent optical applications of the resulting systems have been focused on.     

Distributed Aggregation Algorithms for Mobile Sensor Networks with Group Mobility Model

In many applications of mobile sensor networks, such as water flow monitoring and disaster rescue, the nodes in the network can move together or separate temporarily. The dynamic network topology makes traditional spanning-tree-based aggregation algorithms invalid in mobile sensor networks. In this paper, we first present a distributed clustering algorithm which divides mobile sensor nodes into several groups, and then propose two distributed aggregation algorithms, Distance-AGG (Aggregation based on Distance), and Probability-AGG (Aggregation based on Probability). Both of these two algorithms conduct an aggregation query in three phases: query dissemination, intra-group aggregation, and inter-group aggregation. These two algorithms are efficient especially in mobile networks. We evaluate the performance of the proposed algorithms in terms of aggregation accuracy, energy efficiency, and query delay through ns-2 simulations. The results show that Distance-AGG and Probability-AGG can obtain higher accuracy with lower transmission and query delay than the existing aggregation algorithms.