布沼坝露天矿西帮边坡稳定性分析

布沼坝露天矿西帮边坡受到各种因素的影响,变形不断加剧,严重威胁矿区生产。2010年开始实施边坡清方减载工程,截止目前,西帮边坡1 170 m水平已清帮到界。通过对布沼坝露天矿西帮现状边坡进行数值模拟、极限平衡、监测数据等方面的分析,得出了边坡主煤段变形主要以F7断层为界,F7断层以下主煤段仍处于低速蠕变状态中,但不会发生急速滑坡,F7断层以上边坡处于稳定状态。     

FY卫星系统云图失真问题的一种解决方法

本文针对在保障民航FY静止气象卫星云图接收处理系统运行过程中出现的云图失真故障现象,结合昆明机场卫星接收系统现场安装情况,通过详细分析得出了造成云图失真故障的原因,并给出了故障的解决方法。实践结果表明,本文给出的方法较好地解决了实践工作中出现的投影移位、云层信息大量丢失等云图失真问题。     

加载条件对纳米石墨烯片水泥基复合材料压敏性能的影响

研究不同纳米石墨烯片(GNPs)掺量下加载幅值(15 MPa、20 MPa、25 MPa)和加载速率(100 N/s、300 N/s、500 N/s)对纳米石墨烯片水泥基复合材料(GNPs/CC)压敏性能的影响。试验结果表明:在GNPs掺量低于0.25%(质量分数,下同)时,GNPs/CC的压敏性能与空白组相近;在掺量达到0.3%时,GNPs/CC的电阻变化率最大,且重复性最好。在GNPs掺量为0.3%的情况下,GNPs/CC的电阻变化率与应变随加载幅值的增加而增大,在加载幅值不大于20 MPa时,GNPs/CC的电阻变化率与应变的增加幅度相近,材料的灵敏因子变化较小;在加载幅值达到25 MPa时,由于电阻变化率的增加幅度大于应变的增加幅度,材料的灵敏因子出现了较明显的增加。而加载速率在纳米石墨烯片掺量为0.3%时,对材料的压敏性能无明显影响。     

鱼雷电机-艉轴系统振动与声辐射特性分析

采用结构有限元软件ANSYS和声学边界元软件SYSNOSIE,对鱼雷电机一艉轴系统振动与声学特性数值计算问题进行了研究,建立了带有电机和轴系装置的鱼雷部分舱段的FEM／BEN数学模型。计算了在电机支撑架为刚性支撑和弹性支撑2种情况下,流固耦合模型结构的振动模态以及基于模拟电机激励下的频响分析。获得了鱼雷结构振动响应特征参数。以振动频响分析计算结果作为声学边界条件,比较了2种情况下结构噪声向外辐射的能力。最后考虑了电机空气动力噪声和敷设吸声材料,采用直接边界元法,对鱼雷近场声学特性进行了计算,计算结果表明,用AN- SYS和SYSNOSIE软件能合理地对鱼雷振动及声学特性进行分析,为工程设计提供了有效的工具。     

40 Gbit/s波分技术发展及应用探讨

40 Gbiffs传输是近年来业界关注的焦点之一,本文从全球40 Gbit/s发展趋势、40 Gbit/s传输的市场需求、40 Gbit/s技术及建设成本、光缆性能等方面进行了综合分析,认为以40 Gbids为基础的WDM系统已经趋近成熟并进入规模商用阶段.各运营商应根据自身的实际情况选择适合的网络建设方案.     

Insights into the hydrodynamics in the annular pipe of industrial-scale top-blown smelting furnace

The coaxial jet consisting of swirl jet and axial jet plays a critical role in the industrial processes but is rarely investigated; therefore, it is numerically explored by means of the computational fluid dynamics (CFD) approach in the present work. The force on the swirler, axial and tangential velocity at the annular pipe outlet, and the spatial distribution of swirl number (SN) are selected to evaluate the effect of geometrical parameters on the swirling performance. The results clarify that the velocity and their azimuthal components in the transverse cross-section can be categorized into six segments based on high/low velocity values. The coaxial jets form a weak swirl with high axial, certain tangential, and low radial velocities. x- and y-vorticity vary within −200 to 200 s⁻¹. Coaxial jet mixing decays the SN. Based on the multi-objective matrix analysis, swirler height has the largest effect on swirl performance followed by diameter, angle, and number based on analysis. Optimal parameters are 130° vane angle, 240 mm diameter, 10 vanes, and 250 mm height of the swirler.     

工程施工总承包企业索赔管理研究

介绍了当前我国建筑业施工索赔的现状,分析了总承包企业面临的风险,提出了总承包企业进行有效索赔管理的措施。     

Facile aqueous phase synthesis of 3D-netlike Pd–Rh nanocatalysts for methanol oxidation

The structure-activity relationship between the morphology and composition of Pd-based nanocatalysts is an important fundamental issue in direct methanol fuel cells (DMFC). Three dimensional (3D) netlike Pd–Rh bimetallic catalysts with different atomic ratios (Pd₁Rh₃, PdRh, Pd₃Rh₁) are synthesized through a simple wet chemical way using P123 as a reducing agent and KBr as morphological regulator. The morphology, structure and composition of the catalysts are proved by a series of physicochemical test technology. It is shown that the 3D-netlike structure is composed of short self-assembly nanochains. Electrochemical results display that their application towards methanol oxidation reaction (MOR) in alkaline solution. The MOR activity of the optimized Pd₃Rh₁ nanocatalyst is improved to about 4.0 mA cm⁻², which is much higher than that of the commercial Pd/C catalyst.     

我国不同生态区云烟97烟叶主要品质性状差异分析

为掌握云烟97在我国不同生态区烟叶的主要品质性状差异,系统分析了云南曲靖（清香型烟区）、贵州毕节（中偏清香型烟区）和重庆武隆（中间香型烟区）3个烤烟种植生态区云烟97烟叶的外观质量、化学成分、风格特征和烟气品质。结果表明,贵州毕节烟叶烟气品质综合得分最高,中部叶干草香香韵、香气质、香气量和透发性得分显著高于云南和重庆,还原糖含量和烟气浓度显著高于重庆;云南曲靖烟叶外观质量最好,中部叶总氮含量、氮碱比值以及烟气飘逸感得分均显著高于贵州和重庆,烟气浓度和劲头得分居中,清香型特点显著;重庆武隆烟叶外观质量居中,中部叶总植物碱含量、烟气刺激性、干燥感和悬浮感得分均显著高于云南和贵州,而糖碱比和余味得分则显著低于云南和贵州,中间香型特点显著。由云南经贵州向重庆方向,云烟97烟叶清甜香韵和烟气飘逸感逐渐减弱,木香香韵和烟气悬浮感逐渐加强。     

Elp3 modulates neural crest and colorectal cancer migration requiring functional integrity of HAT and SAM domains

Cell migration is a finely tuned biological process that often involves epithelial-mesenchymal transition (EMT). EMT is typically characterized by the upregulation of mesenchymal markers such as Snail1. This process has been shown to be of critical importance to normal developmental processes, including neural crest migration and invasion. Interestingly, similar mechanisms are utilized in disease processes, such as tumor metastasis and migration. Notably, EMT and EMT-like processes confer tumor cells with the ability to migrate, invade, and adopt stem cell-like properties that largely account for immunosuppression and tumor recurrence. Therefore, identifying sensitive EMT markers may contribute to cancer prognosis and diagnosis in many facets. Previously, we showed that Elp3 plays an essential role during neural crest migration by stabilizing Snail1. In the current study, we further elucidate the molecular mechanism underlying colorectal cancer migration. We found that mElp3 exerted an identical function to xElp3 in modulating neural crest migration, and both HAT and SAM domains are imperative during this migratory process. Interestingly, overexpression of mElp3 in SW480 cells promoted cell migration and invasion, and we further showed that Elp3 stabilized Snail1 requiring integrity of both SAM and HAT domains. Our findings warrant further exploration of the specific target of Elp3 in cancer cells.