护坡工程空心螺母块立浇及安装施工技术研究与应用

空心螺母块因其外形简单,近年来在河湖生态护坡工程中被广泛应用。但护坡工程使用的空心螺母块数量较多,传统的平浇法预制,所需预制场地大且平整度要求高,螺母块运输安装费时费力、外观质量难以保证。文章针对护坡工程空心螺母块浇筑和安装的特点研究出一种操作简便、切实可行的连续立浇预制安装的施工方法,经过工程实际应用,有效保证了预制块的浇筑质量,提高了预制块的运输铺设效率,节约了预制场地的兴建面积。     

悬臂式掘进机截割臂互换性设计

针对现有掘进机多采用单一的横轴式或者纵轴式整机,对不同岩层掘进工作的适应能力差等问题,提出一种面向不同岩层的掘进机截割臂互换性设计方案。对纵、横轴式2种掘进机的结构特点与性能进行了对比分析;针对2种截割臂工作模式的特点,分别设计了相应的截割减速器。Solidworks仿真结果表明,与单一横轴式或者纵轴式掘进机相比,采用互换式截割臂结构可有效提高掘进机对不同岩层截割工作的适应能力,提高掘进效率,节省设备运输及使用成本。     

gain bounds for systems with sector bounded and slope‐restricted nonlinearities

This paper proposes a new method for calculating a bound on the gain of a system comprising a linear time invariant part and a static nonlinear part, which is odd, bounded, zero at zero and has a restriction on its slope. The nonlinear part is also assumed to be sector bounded, with the sector bound being (possibly) different from that implied by the slope restriction. The computation of the gain bound is found by solving a set of linear matrix inequalities, which arise from an integral quadratic constraint formulation of a multiplier problem involving both Zames‐Falb and Popov multipliers. Examples illustrate the effectiveness of the results, and comparisons are made against the state‐of‐the‐art. Copyright © 2011 John Wiley & Sons, Ltd.     

基于时间序列模式表示的异常检测算法*

提出了一种基于时间序列的模式表示提取时间序列异常值的异常检测算法(PREOV).时间序列的模式表示本身就具有压缩数据、保持时间序列基本形态的功能,并且具有一定的除噪能力.在时间序列模式表示的基础上提取异常值,可以大大提高算法的效率和准确性,达到事半功倍的效果.在本算法中,还使用了一定的剪枝策略,使得算法的时间复杂度进一步降低.该算法计算简单、实现方便、无须训练,可以支持时间序列的动态增长.     

新型陶瓷刀具材料的研究与开发

工业用钢材的质量提高使材料加工难度增加,耐高温的高硬度高强度陶瓷材料被用做切削刀具并逐渐推广应用。本文对陶瓷刀具的材质、种类、性能特点作了比较和评价,并重点介绍了新型的晶须增韧陶瓷刀具。最后,对陶瓷刀具的市场前景进行了预测,并指出了陶瓷刀具研制方面应该深入研究的课题。     

陡坡傍山双层行车结构体系受力特性分析

以山区常见的40°陡坡地形条件下修建4车道高等级公路为例,提出一种环境和经济效益俱佳的新型"桩-锚-框架"复合双层行车结构体系,该体系具有双层行车、山体锚固、边坡支挡和路面支撑等众多功能。采用ABAQUS大型有限元分析软件对该双层行车结构体系进行三维数值模拟,探究其受力特性。研究结果表明:该结构体系具有良好的承载能力和静力稳定性,对陡坡山体有较强的支护作用;支撑柱和横梁的相交位置是整个结构体系应力较集中的部位,应适当增加该节点的配筋量以提高强度、改善节点受力情况。     

某坝肩边坡开挖优化设计方案研究

为了研究前坪水库右坝肩边坡在设计方案和优化设计方案开挖下的边坡稳定性分析,采用数值分析和极限平衡法进行研究,首先针对边坡典型剖面进行了数值分析,研究边坡的位移和应力分布规律,然后运用极限平衡法得出边坡的安全系数,两种方法结合不仅可以反映边坡的稳定性和位移场之间的关系,而且可以用工程界所熟悉的安全系数来评价边坡的稳定性。结果表明边坡开挖优化设计方案满足边坡稳定性规范要求,且优化方案减少了开挖量,节省了工程投资,使得工程尽早发挥效益。     

Variability of light absorption properties in optically complex inland waters of Lake Chaohu,China

Absorption coefficients of phytoplankton, colored detrital matter (CDM), non-algal particles (NAP), colored dissolved organic matter (CDOM), and their relative contributions to total non-water absorption (a_t ? w) are essential variables for bio-optical and radiative transfer models. Light absorption properties showed large range and variability sampled at 194 stations throughout Lake Chaohu between May 2013 and April 2015. The a_t ? w was dominated by phytoplankton absorption (a_ph) and NAP absorption (a_d). The contribution of CDOM absorption to a_t ? w was lower than 30%. Phytoplankton and NAP were the primary sources of spatial and vertical variability in absorption properties. Light absorption by CDOM, though significant in magnitude, was relatively constant. CDM absorption (a_dg) was dominated by NAP. The spatial variation of the absorption coefficients from each of the optically active constituents were driven by several main inflow rivers in the western and middle part of Lake Chaohu. Algal blooms and bottom resuspension contributed to vertical variability as observed by phytoplankton and NAP profiles. Specific absorption of phytoplankton had significant spatial and seasonal variations without vertical variation. The spectral slope of absorption showed no significant spatial variability (p > 0.05). Variations of absorption affected different ranges of remote sensing reflectance (R_rs) spectrum, thereby increasing the difficulty of applying the remote sensing algorithm in optically complex waters. Parameters and relationships presented in this study provide useful information for bio-optical models and remote sensing of lakes similar to Lake Chaohu in terms of optical properties.     

浅谈玻璃钢的加工

本文在实际研究和应用的基础上，对玻璃钢的传统加工方法和特种加工方法，如激光切割、纯水射流切割和磨料水射流切割作了简要论述。     

橡胶模型制品胶坯精密预成型机

介绍了橡胶工业橡制品生产中胶坯制备的三种方法，其中详细介绍了精密预成型机制备胶坯。以上海德仁橡塑机械有限公司物精密预成型机为例，从结构，性能及工艺参数等方面进行了分析，说明精密预成型机是批量生产橡胶模型制品的一种得力辅助设备。