Stability of long trench in soft soils by bentonite-water slurry

A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was examined by constructing long trenches using different slurries. The soil deformation and surface settlement induced by the excavation of the trench are found to be closely related to slurry type and excavation depth of the long trench. Increasing the bentonite concentration of the slurry has beneficial effects on stability： 1） larger particles can improve local and global stability in cases where filter cakes do not form, and 2） larger viscosity can promote filter cake formation on the walls of long trenches excavated in soft clay and enhance their stability.     

An investigation on electrochemical performances of as-cast and annealed La0.8Mg0.2Ni3.3Co0.2Six（x = 0-0.2） alloy electrodes for Ni/MH battery application

The La-Mg-Ni-based A2B7-type La0.5Mg0.2Ni3.3Co0.2Six （x=0-0.2） electrode alloys were prepared by casting and annealing. The influences of the additional silicon and the annealing treatment on the structure and electrochemical performances of the alloys were investigated systemically. Both of the analyses of XRD and SEM reveal that the as-cast and annealed alloys are of a multiphase structure, involving two main phases （La, Mg）2Ni7 and LaNi5 as well as one minor phase LaNi3. The addition of Si and annealing treatment bring on an evident change in the phase abundances and cell parameters of （La, Mg）2Ni7 and LaNi5 phase for the alloy without altering its phase structure. The phase abundances decrease from 74.3% （x=0） to 57.8% （x=0.2） for the （La, Mg）2Ni7 phase, and those of LaNi5 phase increase from 20.2% （x~0） to 37.3% （x=0.2）. As for the electrochemical measurements, adding Si and performing annealing treatment have engendered obvious impacts. The cycle stability of the alloys is improved dramatically, being enhanced from 80.3% to 93.7% for the as-annealed （950 ℃） alloys with Si content increasing from 0 to 0.2. However, the discharge capacity is reduced by adding Si, from 399.4 to 345.3 mA.h/g as the Si content increases from 0 to 0.2. Furthermore, such addition makes the electrochemical kinetic properties of the alloy electrodes first increase and then decrease. Also, it is found that the overall electrochemical properties of the alloys first augment and then fall with the annealing temperature rising.     

Kinetics study of leaching arsenic from Ni-Mo ore roasting in dust mixture of hydrochloric and sulfuric acids

The kinetics of leaching arsenic from Ni-Mo ore roasting dust was investigated. The effects including leaching temperature, particle size of the smelter dust, stirring speed, the coefficient β（the molar ratio of sodium chlorate to arsenic in the smelter dust） and the initial H＋ concentration on leaching arsenic were studied. The results indicate that the leaching of arsenic increases sharply with the decrease of particle size. The orders of reaction with respect to H＋ concentration and particle size are determinted to be 1.136 and 1.806, respectively. The leaching of arsenic reaches 99% under experimental conditions, the apparent activation energy is determined to be 11.157 kJ/mol, which is consistent with the values of activation energy for diffusion model The kinetics equation of leaching arsenic from the roasting dust could be expressed by a semi-empirical equation as 1-2/3η （1 -η）^2/3 = k0（c[H＋]）^1.136ro^-1.806 exp[（-11157 /RT）t].     

基于行波法的10kV电缆单环网在线故障定位系统

针对电缆单环网故障定位问题,本文以行波理论为基础,对10kV电缆单环网在线故障定位系统进行研究。通过对电缆单环网结构进行分析,将单环网分为不同级别的T型组合单元,对每个T型电缆单元提出具体测距原理及算法,同时对所有的T型单元依次进行测距并统计分析测距结果,汇总后得到单环网的测距结果,并利用电力系统仿真软件(power system computer aided design,PSCAD)对T型单元故障进行仿真,仿真结果验证了算法和判据的可行性与正确性;最后对电缆单环网在线故障定位系统的硬件和软件进行设计。该系统可以实现对10kV电缆单环网故障的在线监测和定位,与其他测距装置相比,可以快速准确地找到故障点,从而减少停电检修时间,确保供电可靠性,有利于提高经济效益。     

二元生成自由群的幂单性质(英文)

为了研究二元生成自由群的幂单性质,依据组合群理论,讨论了本原元素的若干组合方式,证明了可用于处理幂零的几组新方程.证明了可以嵌入一般线性群的二元生成自由群是幂单群的充要条件是它的每个本原元素均是幂单的.     

战场宽带数据链分布式虚拟骨干网的构建

宽带数据链作为现代战场的神经网络和信息传输通道,必须采用分布式虚拟骨干网构建算法才能适应战场环境的大容量、多样性数据传输和时变性网络结构。针对这一问题,提出了一种分布式虚拟骨干网构建算法-DCDS算法。该算法中,每个节点只需获取其两跳范围内的邻居节点信息,无需获知全网拓扑信息。理论分析和仿真表明,相比Wu等2种经典算法,DCDS算法具有更小的消息开销和虚拟骨干网构建规模,更适合于大数据量、高动态的战场宽带数据链网络。     

地震信息中富水特性的分析

地震勘探取得的地震资料中包含了丰富的地质信息,目前地震资料主要用于解决地质构造问题,其中蕴含的水和瓦斯等岩性信息没有得到充分利用.针对某矿勘探地震资料包含富水信息的反演成果与瞬变电磁法的探测范围及钻孔水文资料标定分析成果进行联合对比分析,吻合性较好.由此可见,从地震资料中提取富水信息是可行的,在实际运用中不仅为矿方提供更为准确的水文地质资料而且也节省了成本,取得了较好的经济效益.     

梳棉机针布选配与工艺优化

探讨了梳棉机针布选配和工艺参数的选择问题。通过工艺对比得出,纺C14.6 tex棉纱时针布选配应按照锡林针布稀、盖板针布密的原则进行。在生条定量3.9 g/m、刺辊速度970 r/min、锡林速度403 r/min工艺条件下,有利于进一步提高成纱质量。     

含氮、磷有机配体对(CdSe)_2量子点结构和电子性质的影响

使用密度泛函理论方法研究了量子点(CdSe)2与配体L(L=PH3、PH2Me、PHMe2、PMe3、NH3、NH2Me、NHMe2、NMe3)之间的相互作用及其产物的结构和性质。配体中的P或N原子与Cd原子上分别形成较强的Cd—P和Cd—N配位键,从而影响(CdSe)2的结构和电子性质。配体作用下,(CdSe)2的几何结构、电荷分布、轨道能级、吸收光谱等均发生变化,但2类配体的影响,尤其是甲基数目的影响,存在较大差异。