烧结矿碱度对综合炉料交互反应的影响

以不同碱度的烧结矿及烧结矿与块矿的混合矿为研究对象,利用荷重软化熔滴装置,考察了烧结矿碱度对综合炉料软熔性能及不同炉料间交互作用的影响。研究发现:随着烧结矿碱度增加,炉料结构中块矿的质量配加比例提高,炉料间的交互作用增强,主要表现为综合炉料软化开始温度及熔融开始温度降低,混合炉料的透气性得到改善。炉料结构的变化使矿物间的交互反应随着烧结矿碱度的提高而增强,进而导致液相成分发生改变,降低了初渣物相熔点,而烧结矿碱度过高时会恶化料柱的透气性。同时通过扫描电子显微镜?能量色散谱仪(SEM?EDS)及X射线衍射(XRD)精修表征整个还原过程烧结矿物相变化,渣相中主要物相为浮氏体和硅酸钙,随着烧结矿碱度增加,在不同断点2CaO·SiO₂的含量呈现降低趋势,表明烧结矿还原过程生成的高熔点物相随之降低,综合炉料的液相生成温度随之降低,炉料间交互作用增强。因此,适当提高烧结矿碱度,提高块矿入炉的质量配比,利于高炉的强化冶炼。      

Quantitative and qualitative analyses in near infrared analysis of basic compounds in sugar beet leaf

The application of the near infrared technique (NIR) on a large scale is possible thanks to the use of rapid and inexpensive computers, and facilitates both quantitative and qualitative analyses. The great advantage of NIR is rapid analyses and its non-destructive character, and possibility of measuring many different components at the same time. The NIR method was used to study changes in chemical composition in leaves of sugar-beet under the influence of various fertilizers. The results obtained show that this method is an effective tool to predict protein, nitrogen and saccharides.     

基于联盟的6G无人机通信网络优化概述

随着6G网络和无人机(UAV)技术的迅猛发展,无人机通信网络将成为6G空天地一体化网络融合的关键组成部分,在战场侦查、野外救援和物联网信息传输等民用和军用领域发挥重要作用。针对无人机群大规模、高动态和自组织等特性,以6G网络任务驱动为出发点,该文提出基于联盟的6G无人机通信网络优化框架。围绕联盟形成、联盟任务实施和联盟资源管理对无人机联盟工作原理展开论述。结合博弈论、机器学习和在线决策,给出了无人机通信网络资源优化方法和仿真示例。最后,对6G无人机通信网络的应用前景和亟需解决的问题进行了开放性讨论。     

An experimental and analytical investigation of axial crack propagation in long pipes

Experimental pressure histories, axial and circumferential strains, and crack-opening shapes were compared with the predictions of a simplified model of a fracturing pipe. This model, based upon previous analytical and numerical studies, assumed that the axial strains were negligible. The comparison showed that this assumption was valid only for relatively thickwalled pipes. An analytical energy analysis, based upon experimental data, indicated that the primary energy absorption in thin-wall pipes was the axial stretching of the pipe flaps formed by the propagating crack. The pressure profiles and crack shapes developed by modifying the model to account for the axial strain energy compared well with the experimental results. This good agreement indicates that accurate predictions of dynamic axially propagating cracks may be made using a ring model which will consider the axial energy and the frictional shear forces which exist between longitudinal sections.     

二维切换系统指数镇定问题研究

对于由两个不稳定的线性时不变子系统构成的二维切换系统,利用逐段光滑Lyapunov函数方法研究其指数镇定问题．通过切换面及相应Lyapunov函数的适当参数化,导出了关于可指数镇定性的代数判据,由此得到切换面及Lyapunov函数的求解方法．算例验证了该理论的灵活性与有效性．     

不同质量分数水的微乳化柴油微观结构及其燃爆性能

借助高分辨率透射电镜(HRTEM)和纳米激光粒度分析仪(NLPSA),测定了含有不同质量分数水的微乳化柴油中“油包水”(W/O)粒子的微观结构和粒径分布特征;使用液体燃料可持续燃烧性能测定装置和液体燃料爆炸性能评定装置,测定其燃烧和爆炸性能。结果表明,随着微乳化柴油中水的质量分数增加,W/O粒子的平均粒径逐渐增加,粒径分布逐渐变宽,粒径均匀性变差。微乳化柴油中的水的质量分数与其燃爆性能并不是简单的线性关系,而是存在一个最佳值。在考察范围内,水质量分数为10%的微乳化柴油中的W/O粒子对应的平均粒径为25 nm,且粒径分布均匀,微乳化柴油闪点最高,强行点火不能持续燃烧,爆炸后的最大压力比配制微乳化柴油用的-10号军用柴油降低14.3%,是一种燃爆倾向显著降低的安全燃料。     

声表面波纵向耦合谐振滤波器通带特性研究

在理论方面,作者应用COM理论分析研究了纵向耦合谐振滤波器通带波纹大小和耦合换能器与输入/输出换能器间距离的关系。在工艺上,作者采用剥离工艺制作了相应的纵向耦合谐振滤波器,并给出了所设计的纵向耦合谐振滤波器频率响应的测试结果。实验测得样品滤波器中心频率为895 MHz,1 dB带宽40.5 MHz,阻带抑制达到47 dB,插入损耗3.8 dB,通带波纹小于0.9 dB。实验与理论分析比较一致。     

Determination du taux de comptage en amont d'un temps mort generalise

The Takács formula, which gives the output count rate for a Poisson process after a generalized dead time, is reversed analytically: the same series yields the two possible input count rates. An application is made to the numerical determination of the input count rates by an iterative method.     

基于协议状态机遍历的模糊测试优化方法

针对现有的协议模糊测试技术存在报文重复交互、输入盲目等问题,提出一种基于协议状态迁移遍历的模糊测试优化方法。该方法将协议状态迁移遍历问题转化为中国邮路问题,求解遍历所有协议状态迁移的最短路径,并依据该最短路径对各个状态迁移进行测试。在测试过程中,通过分析协议实体在执行测试用例后的响应报文,动态调整后续的报文输入,进而避免无效交互。同时利用UIO序列判断协议实体状态是否发生异常迁移,及时检测协议逻辑漏洞。实验结果表明,该模糊测试优化方法可以显著提高测试效率与漏洞挖掘能力。     

Performance of single vertical helical anchor embedded in dry sand

An investigation into the uplift behavior of single vertical helical anchor embedded in dry sand presented. A series of laboratory tests have been conducted to determine the effect of the embedment ratio, shaft diameter ratio and sand density against the uplift capacity of helical anchor. The laboratory tests were conducted in a small scale model in loose and dense sand. A sand placement technique was utilized over the testing program to achieve the predetermined depth. In this testing program, the uplift load and uplift displacement have measured. The observation of failure mechanism and the measurement of pullout load and the vertical displacement analyzed and discussed. A number of graphs will be plot between the uplift capacity and the factors to obtain their relationships. From the analysis, the uplift capacity is increase with the increase of embedment ratio and sand density however the shaft diameter ratio is not significantly influent to the uplift capacity. In the observation of failure mechanism, the failure surface proposed for the helical anchor embedded in loose and dense sand. For loose sand package, local failure surface observed however for dense sand package, a truncated cone shape failure surface was observed. From the analysis, an empirical model was proposed. The proposed empirical model compared with the experiment result and existing theories to verify the validity of the empirical model.