非确定性视角下的产业类历史地段更新探索——郑州市国棉三厂厂区更新设计

产业类历史地段的更新,是现阶段城市更新中的重要课题。从非确定性视角出发,对郑州市国棉三厂厂区的更新设计进行了一定的探索。结合现有城市规划中存在的问题,提出保护和保留原有的厂房和构件,采用拼贴式、微循环的模式进行更新,在设计中体现了变化的、动态的、整体的、弹性的思想观和"混合共生、灵活应变"的设计理念。     

Effects of Al addition on the phase transformation and interfacial evolution in multilayer Ti-B4C composite

The fully-dense multilayer Ti-B₄C composite doped with 6 wt% Al was fabricated via tape-casting and hot-pressing sintering at 1800 °C and under a uniaxial pressure of 30 MPa for 60 min. The effects of Al addition on the phase composition, interfacial microstructure and fracture toughness of the laminate composite were investigated. Based on the results of WDS and EDS, Al addition was proved to be effective on accelerating atom diffusion between Ti and B₄C due to the melting pool around interface where liquid Al enriched, besides, it helps to transform the interfacial bonding method of physical to metallurgical. Finally, the improvement on toughness of Al doped composite can be attributed to the strong metallurgical bonding and hybrid fracture mode of interface. Our study may provide a potential method for producing high strength and toughness multilayer metal/ceramic composites.     

基于MDA技术的电子公文管理系统的设计

为了解决电子公文管理系统开发过程中的异质性问题,在基于OMG的模型驱动构架思想的基础上,进行系统建模过程的优化研究,在此基础上进行电子公文流转流程的规律探讨,总结出相应的电子公文管理系统的设计开发思路。     

内河限制性航道护岸全生命周期能耗计算方法

为指导内河护岸工程节能及形式选择,建立了护岸工程全生命周期各个阶段的能耗计算模型,护岸工程的总能耗由结构物能耗、运输及施工能耗、维修和拆除能耗组成。以盐河CL型护岸为实例进行计算,结果表明：所建立的内河限制性航道护岸全生命周期能耗模型能够很好地评价护岸各阶段的耗能情况,且结构物能耗占比最大,拆除能耗占比也较大,护岸工程节能应做好结构物选型,延长护岸的寿命,避免护岸拆除。     

A novel fabrication route to microlaminated TiB2–NiAl composite sheet with {111}<μνω> texture by roll bonding and annealing treatment

Microlaminated TiB₂–NiAl composite sheet consisting of alternating NiAl and TiB₂-rich layers has been successfully fabricated. This fabrication method is composed of roll bonding for producing a multi-laminated Ni–(TiB₂/Al) sheet from Ni sheets and TiB₂/Al composite sheets, and of subsequent annealing treatment for forming a NiAl intermetallic phase by reaction diffusion. Microlaminated TiB₂–NiAl composite sheet obtained by this method exhibits strong {111}<μνω> texture. The formation mechanism of such texture by reaction diffusion has been discussed in view of texture inheritance. This method could utilize reaction diffusion to control texture component of materials, which is expected to provide an access to synthesize materials with texture for special requirement.     

一种用于数字峰值电流模Buck的高精度DPWM设计

为减小脉冲关断延迟,提出了一种用于数字峰值电流模Buck的高精度数字脉冲宽度调制器(DPWM)的设计方案。采用粗调与细调相结合的分段式架构思想,粗调部分由全局时钟控制计数器-比较器模块构成,细调部分由锁相环组成的相移电路、计数器-比较器、多路选择器和逻辑门构成,以此产生不同精度的两段式延迟叠加,实现较高的DPWM输出精度。采用Vivado和Xilinx7系列FPGA,仿真并测试了搭载高精度DPWM的Buck。仿真结果表明,DPWM时间分辨率为250 ps,精度为0.01%。此外,测试结果表明,与低精度DPWM相比,设计的高精度DPWM一定程度上抑制了系统的极限环振荡,提高了Buck的环路带宽及系统稳定性。     

包装用杨木胶合板表面超疏水处理及其性能研究

目的 提高胶合板尺寸稳定性及增强胶合板的疏水性，拓宽胶合板的应用领域和范围。方法 将硅酸钠溶液与乙烯基三乙氧基硅烷共混形成不同物质的量之比的混合物，经搅拌、冷凝、再搅拌得到有机硅聚合物，然后浸渍处理胶合板，使用傅里叶红外光谱仪分析改性前后胶合板表面羟基含量及其改性机理；通过环境扫描电子显微镜表征改性胶合板表面的微观形貌；利用万能力学试验机探究改性前后胶合板力学性能；借助接触角测试仪比较改性前后胶合板的润湿特性，并计算其吸水率及吸水厚度膨胀率。结果 有机硅氧烷成功地键合到胶合板的表面；改性前后胶合板力学性能无明显变化；以物质的量之比为2∶5的有机硅聚合物浸渍处理的胶合板的吸水率及厚度膨胀率较低；在接触角测试中，物质的量之比为2∶5的有机硅聚合物处理后的胶合板初始接触角达到156.8°，60s后接触角依然有140.3°，始终保持超疏水状态。结论 有机硅聚合物处理后胶合板的疏水性能及尺寸稳定性均有较大的提高。     

Blue-green photoluminescent 5- and 10-connected metal 5-(4′-carboxy-phenyl)tetrazolate coordination polymers

Hydrothermal reaction of Zn/Cd salts, NaN₃ and 4-cyanobenzoic acid via in situ [2 + 3] cycloaddition generated two blue-green photoluminescent coordination polymers [Zn(cptta)(H₂O)] (1) and [Cd(cptta)(H₂O)] (2) (H₂cptta = 5-(4′-carboxy-phenyl)tetrazole). When only metal ions are considered as nodes, 1 shows rare 5-connected Shubnikov plane topological type and 2 has unprecedented 10-connected {3¹².4²⁴.5⁹} topological type.     

CFG桩网复合地基加固物流地坪深厚软土地基的三维数值模拟分析

结合湖州某物流园采用CFG桩网复合地基处理大面积深厚软土的工程实例,运用Midas GTS有限元软件建立桩网人工复合地基三维固结模型,计算模拟不同垫层厚度、土工格栅层数、桩长等设计参数对沉降变形的影响以及土工格栅在桩网固结模型中的受力特征。计算结果表明:地基整体沉降变形随填土垫层厚度的增加而增大,随土工格栅层数的增加而减小,随桩长增加而减小;土工格栅最大拉力随着土工格栅层数增加而减小,在桩帽顶部角点处产生部分应力集中,且在桩帽之间挠度明显增加。为此,控制垫层厚度、土工格栅层数、桩长等措施能有效减小地基沉降变形,为今后软基沉降控制等相关工程提供借鉴。