电气化铁路既有线深路堑扩堑石方控制爆破

介绍电气化铁路既有线无隔墙台阶爆破扩堑方法。沿既有线方向设置低台阶 ,边界处布置光爆孔 ,采用“同列同段和列间微差”的起爆网路。采用自制的“炮被”和架设“钢管排架”阻挡飞石、滚石和滑石 ,确保了既有线的安全。文中还概述了“炮被”和“钢管排架”的制做以及作者的认识和体会。     

Deposition of UF5 on the surface of steel material having oxide coating in contact with gaseous UF6

When UF6 is handled in leak tight system, the amount of uranium compound formed on the surface of containers, valves, and others in UF6 handling facilities is not so significant for a short term that special attention has not been given to this problem. The present work was done to throw some more light on this problem based on the recent experiment. We discuss the possibility that the intermolecular transfer of a fluorine atom from UF6 to UF5 may participate in the formation of uranium compound. The discussion includes also the unique features contained in the experimental result, the reaction processes assumed in this problem, and the derivation of a rate equation for expressing the deposition of uranium compound. Furthermore, we propose a new method for determining nonlinear parameters included in a governing differential equation having two variables for expressing the deposition of uranium compound from experimental raw data.     

Robust Control of Permanent Magnet Synchronous Motors

In this paper, permanent magnet synchronous motors (PMSMs) are investigated. According to the feature of PMSMs, a novel state equation of PMSMs is obtained by choosing suitable state variables. Based on the state equation, robust controllers are designed via interval matrix and PI control idea. In terms of bilinear matrix inequations, sufficient conditions for the existence of the robust controller are derived. In order to reduce the conservation and the dependence on parameter, the control inputs of PMSMs are divided into two parts, a feedforward control input and a feedback control input, and relevant sufficient conditions for the existence of the controller are obtained. Because of the suitable choice of state variables, the proposed control strategies can cope with the load uncertainty and have robustness for disturbance. Finally, simulations are carried out via Matlab/Simulink soft to verify the effectiveness of the proposed control strategies. The performance of the proposed control strategies are demonstrated by the simulation results.      

Study on metamerism degree evaluation based on wavelength sensitive cone weighting algorithm

Metamerism phenomenon can be used in illuminant detection to ensure the accuracy of light source. A method based on Long‐, Middle‐, Short‐ wavelength cones(LMS) weighting algorithm to evaluate metamerism degree is proposed. The chromatic relationship between the degree of metamerism mismatch and the light source is studied. Herein, the consistency between the metameric indices (MIs) and CIE1976 L*a*b* color difference ranking is analyzed by SRCC, KRCC, PLCC and RMSE. A statistically sampling method to obtain practical LMS cone fundamentals to evaluate metamerism degree is employed. The analysis results obtained show that the method based on LMS weighting algorithm has good evaluation ability and stability in simulation experiments and statistically sampling experiments, which are in line with visual characteristics of human. Proposed method meets the requirements of selecting metameric pairs used in light source detection. The analysis results have certain guiding significance.     

Single-Crystalline TiO2(B) Nanobelts with Unusual Large Exposed {100} Facets and Enhanced Li-Storage Capacity

The {100} facet of single-crystalline TiO₂(B) is an ideal platform for inserting Li ions, but it is hard to be obtained due to its high surface energy. Here, the single-crystalline TiO₂(B) nanobelts from H₂Ti₃O₇ with nearly 70% {100} facets exposed are synthesized, which significantly enhances Li-storage capacity. The first-principle calculations demonstrate an ab in-plane 2D diffusion through the exposed {100} facets. As a consequence, the nanobelts can significantly accommodate Li ions in LiTiO₂ formula with specific capacity up to 335 mAh g⁻¹, which is in good agreement with the electrochemical characterizations. Coating with conductive and protective poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), the cut-off discharge voltage is as low as 0.5 V, leading to a capacity of 160.7 mAh g⁻¹ after 1500 cycles with a retention rate of 66% at 1C. This work provides a practical strategy to increase the Li-ion capacity and cycle stability by tailoring the crystal orientation and nanostructures.     

某污水处理厂MBR膜系统改造与运行管理

某污水处理厂设计规模为10万t/d,采用AAO+MBR工艺,设计出水水质满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准。由于运行时间较长,MBR运行系统存在产能下降、膜丝断丝脱落、污堵和清洗频次以及强度增加等问题,严重影响正常生产运行。针对MBR系统运行中存在的问题,文中提出具体改造建议,并总结运行经验,进一步优化MBR膜系统的运行维护管理,为其他污水厂MBR膜系统运行问题提供解决思路和维护管理经验。     

吴庄铁矿盘区间柱回采优化研究

基于吴庄铁矿盘间柱宽度不确定性、两侧均为充填体且高度大的现状，为安全高效回采盘区间柱，制定了盘区间柱两侧采场充填体取芯设计方案，并对充填体进行制样，进行了实验室试块抗压强度试验。试验结果表明：一步骤采场（矿柱）充填体强度整体符合设计强度要求，二步采场充填体强度整体偏低，盘区间柱宽度较设计变化较大，宽度极其不规整，整体呈上窄下宽的规律。鉴于盘区间柱宽度不规则、二步骤采场充填体强度低于预期、采场高度大和盘区间柱回采时不能大面积暴露的特点，采用留设一定厚度间柱和采用较小采场长度的措施进行回采方案制定，制定了小采场分段空场嗣后充填法回采方案。该方案的制定和实施，对于其他类似地下矿山三步骤间柱回采工程具有借鉴意义。     

二滩拱坝初次蓄水的变位监测反分析

简要介绍了在二滩拱坝1998年5月初次蓄水期,通过拱坝垂线和监测网系统,用统计模型和确定性模型理论分析方法,建立了施加于坝体各作用量与坝体受作用后的效应量(变位)间的数学关系;并根据预先计算分析成果,提出了在初次蓄水运行中拱坝变位的参考预报值,实时对二滩拱坝实际工作状态作出安全评判。