高强钢筋混凝土梁的裂缝及挠度研究

基于钢筋混凝土结构非线性有限元基本理论,根据高强钢筋混凝土结构力学性能的特点和有限元法,在引入混凝土多参数强度准则和非线性本构关系的基础上,对高强钢筋混凝土梁进行了裂缝和挠度的计算及分析,并与实验和理论值进行对比,结果表明二者吻合较好.     

甘蔗收割机切割系统耙齿注塑成型翘曲变形分析

针对传统甘蔗收获机切割系统甘蔗喂入困难问题,设计了新型的甘蔗耙齿,将其安装在切割器上,以甘蔗收割机切割系统耙齿制品为研究对象,为了避免注塑成型方案加工使新型耙齿易出现翘曲的现象,文章利用Moldflow模流分析软件和正交试验方法,研究了保压压力、保压时间、熔体温度和模具温度对制品翘曲的影响。结果表明,保压压力对翘曲缺陷影响最大,保压时间的影响最小。根据正交试验结果,选择了最优工艺对翘曲进行了优化,结果显示,当保压压力为120 MPa,保压时间为12 s,熔体温度为220℃,模具温度为55℃时,耙齿的翘曲量最小。     

Effect of a starch-based filter aid on the dewatering of fine clean coal

The dewatering of fine, flotation cleaned coals from Huaibei and Xuzhou (bituminous) and Yongcheng (anthracite) were studied. The supernatant and filter cake were examined to determine the rate and extent of flocculation and dewatering. A starch-based filter aid was used to increase flocculation and dewatering rates. The filtration constant, K, and compression index, s, of the Yongcheng slurry were measured under various conditions. A designed experiment was performed to determine optimum conditions for dewatering. The results showed that the filter aid enhanced flocculation and coagulation of the fine cleaned coal slurry, enhanced the structure of the filter cake and promoted dewatering of the cake. Moisture content in the cake was reduced to 17% after vacuum filtration.     

Quality of security adaptation in parallel disk systems

In the past decade, parallel disk systems have been highly scalable and able to alleviate the problem of disk I/O bottleneck, thereby being widely used to support data-intensive applications. Although a variety of parallel disk systems were developed, most existing disk systems lack a means to adaptively control the quality of security for dynamically changing workloads. We address this gap in disk technology by designing, implementing, and evaluating a quality of security control framework for parallel disk systems, or ASPAD for short, that makes it possible for parallel disk systems to adapt to changing security requirements and workload conditions. The ASPAD framework comprises four major components, namely, a security service middleware, a dynamic data-partitioning mechanism, a response time estimator, and an adaptive security quality controller. The framework is conducive to adaptively and expeditiously determining security services for requests submitted to a parallel disk system in a way to improve security of the disk system while making an effort to guarantee desired response times of the requests. We conduct extensive experiments to quantitatively evaluate the performance of the proposed ASPAD framework. Empirical results show that ASPAD significantly improves the overall performance of parallel disk systems over the same disk systems without using the ASPAD framework.     

基于方式变化影响域辨识及故障量排序的继电保护定值在线预警

提出了基于方式变化影响域和故障量排序的继电保护定值快速在线预警方法。该方法以保护所在位置的短路电流、分支系数等继电保护定值计算相关故障量的变化率为判据,确定线路和变压器等电网元件开断后,定值将受到显著影响的保护集合。通过对故障量计算结果的排序优化来进一步提高定值在线分析的速度,实现继电保护定值的快速在线预警。工程实际应用表明,该方法可以快速准确地预警存在保护定值隐患的电网特殊运行方式和保护装置。     

工程图学与金工实习结合的新全程教育体系研究

介绍了工程图学与金工实习结合的教学新体系研究和实践,提出了图学教学的新思路,强调了图学教学中实践、创新的重要作用,将图学知识的学习和图学实践相结合,着重对学生的综合素质、工程意识和创新能力的培养,在教学中通过教学对比的方式对新课程体系进行检验,取得了初步成效.     

复杂条件下岩土工程的可靠度分析

由有限元技术与可靠度分析方法相结合 ,通过动态规划技术将可靠性理论运用到复杂工程的稳定性分析中 ,完整地提出了复杂岩土工程的可靠度分析方法 ,建立动态规划的数学模型 ,推导了确定复杂岩土工程的最危险滑动线及相应的最小可靠指标的计算方法 ,编制相应的计算程序。最后以工程为例 ,进行稳定性可靠度分析 ,并得出了有益的结论     

Monodomain Liquid Crystals of Two-Dimensional Sheets by Boundary-Free Sheargraphy

Nano-Micro Letters - Ultrathin, lightweight, and flexible aligned single-walled carbon nanotube (SWCNT) films are fabricated by a facile, environmentally friendly, and scalable printing...     

刃倾角对刀具工作角度影响的理论分析

对刀具刃倾角λs≠ 0°时刀具的标注角度、实际工作角度进行了理论分析 ,推导了λs 影响下的工作角度计算公式 ,并给出了λs 对刀具工作角度的影响曲线。     

行车轨道几何形位检测系统研制

根据起重机行车轨道检测的实际需要,探讨基于测量机器人和遥控小车的轨道几何形位检测系统的框架和研制方法。首先通过软件自动控制测量机器人测量遥控小车上的棱镜,得到轨道顶面离散三维数据,接着剔除粗差,计算轨道的几何参数,最后对轨道质量进行定量分析。通过工程实例证明,该系统应用于轨道几何形位检测是可行的。