轻组分绝对占优的蒸汽再压缩隔离壁蒸馏塔的最优拓扑结构

隔离壁蒸馏塔（DWC）的双塔多段拓扑结构导致蒸汽再压缩热泵（VRHP）的应用具有多种可能性，包括单VRHP、多VRHP、多级VRHP以及它们的相互组合等复杂结构，这显著加剧了蒸汽再压缩隔离壁蒸馏塔（DWC-VRHP）综合与设计的复杂性与烦琐性。为解决这一问题，针对轻组分绝对占优的三元宽沸点物系的分离问题推演了DWC-VRHP的最优拓扑结构，由此能够有效回避系统综合与设计过程中的结构搜索问题并显著降低模型化与搜索计算的工作强度。轻组分绝对占优与宽沸点物性导致了塔顶冷凝器与预分离蒸馏塔的提馏段是主要的热源与热阱，也决定了DWC-VRHP的最优拓扑结构，即一个二级VRHP与DWC的耦合系统。第一级VRHP用于进料预热，既充分利用温度提升跨度小的特点，又可以通过进料分流强化气液相间的物质传递。第二级VRHP用于加热预分离蒸馏塔的提馏段（或公共提馏段），能够最大限度地降低分离操作的非可逆性。采用苯/甲苯/邻二甲苯和正戊烷/正己烷/正庚烷两个物系的分离问题对所提出的DWC-VRHP的最优拓扑结构进行了分析与验证。通过与DWC以及DWC-VRHP其他潜在结构的系统性比较，显示了所提出系统结构在稳态性能方面的优越性。     

我国竹纤维及制品标准体系的现状与发展建议

本文首先概述我国竹纤维及制品标准的现状,然后分析其存在问题;在此基础上借鉴相关国际组织及发达国家标准体系的特点和经验,对我国竹纤维及制品标准体系发展提出若干建议。     

浅谈高效节能循环水泵及配套节能技术在我公司的应用效果

为解决制盐分厂循环水系统存在的水泵能耗高、噪声大等问题,在基于"合同能源管理"模式下,对循环水系统进行了节能技术改造,取得了明显的节能效果。     

儿童友好视角下城市公园品质与可达性研究——以巴塞罗那学龄前儿童为例

具备可进入的绿色空间、游乐场地是儿童友好城市衡量中的核心指标，也是城市公园提供的必要服务之一。聚焦对城市公园需求度和使用率较高的学龄前儿童，尝试建构综合考虑城市公园品质和可达性的分析及评估方法。选取联合国儿童友好城市——西班牙巴塞罗那为案例，基于实地调研、开源地图、官方统计数据等，使用儿童友好的公园品质指数（QUINPY）和空间句法可达性模型开展综合评价，并结合学龄前儿童人口密度分布，提出有针对性的改善建议，基于不同的需求和现状，选取改善城市交通步行环境、合理增加结构性设施或者鼓励分时段及立体化拓展空间使用可能性等适宜性创新措施。以期为我国儿童友好导向的城市公园发展建设提供参考。     

In situ characterization of LiY(WO4)2 nanotubes for electrochemical energy storage

Here, LiY(WO₄)₂ nanotubes are prepared via a feasible electrospinning technique. This new anode material shows excellent electrochemical properties. The capacity loss of LiY(WO₄)₂ nanotubes is as low as 6.9% after 156 cycles, while bulk LiY(WO₄)₂ presents the capacity loss higher than 55.0%. Even after 600 long-life cycles, the capacity loss of the nanotubes is only 9%. It can be seen that the hollow structure with a rough surface and a porous morphology contributes to the improvement of electrochemical performance. Furthermore, online X-ray diffraction (XRD) method is firstly applied to understand the lithium ions insertion/extraction mechanism of LiY(WO₄)₂ nanotubes. It can be concluded that it is an asymmetrical two-phase reaction. A phase transformation from LiY(WO₄)₂ to Li₃Y(WO₄)₂ can be obviously seen from the in situ XRD during discharge process. While Li₂Y(WO₄)₂ appears as an intermediate phase with a reverse charge reaction. In addition, in situ XRD also demonstrates that LiY(WO₄)₂ nanotubes have surprised electrochemical reversibility. All the above results indicate that LiY(WO₄)₂ nanotubes can be expected to be anode candidate for rechargeable lithium ion batteries (LIBs).     

核主泵转速传感器抗震反应谱试验的实现方法

为完成核主泵转速传感器的抗震试验,设计一套放大装置,对其进行了频响分析、瞬态时程分析和试验调试.通过频响分析初步确定放大装置的结构形式和尺寸;通过瞬态时程分析得到给定输入条件下放大装置所要求位置的反应谱曲线,进一步确定设计的放大装置的可行性;根据瞬态分析结果及地震试验台性能对放大装置进行多次调试.结果 表明:放大装置上所要求位置的试验反应谱能够包络要求反应谱,核主泵转速传感器完成抗震试验.     

Enhanced Magnetoresistance Effect and Magnetic Properties of Double Perovskite La2−xSrxMnRuO6 (0 ≤ x ≤ 1.0)

Journal of Superconductivity and Novel Magnetism - Double perovskite La2?xSrxMnRuO6 (x?=?0, 0.3, 0.5, 0.8, 1.0) samples were synthesized by the standard solid-state reaction...     

One-step fabrication of heterostructured CoNi-LDH@NiCo alloy for effective alkaline hydrogen evolution

Construction of heterostructured electrocatalyst with interface effect is an effective strategy for enhancing the alkaline hydrogen evolution efficiency, whereas this process often requires complex treatments. Herein, we proposed a one-step electrodeposition method to obtain heterostructured CoNi-LDH@NiCo alloy on Ni foam (NF) through a competition reduction between NO₃^? group and metal cations in the electrolyte. The HER performance for the CoNi-LDH@NiCo alloy achieved the current density of 10 mA cm^?2 at overpotential of 69 mV in 1 M KOH solution, improved 60% for η₁₀ by comparing with the pristine NiCo alloy. Utilizing the specialized adsorption of CoNi-LDH for H₂O and the featured attractiveness of NiCo alloy for H atom, the interface effect of the heterostructure electrocatalyst accelerated the dissociation of water molecules and elevated the catalytic kinetics dramatically. This work points out a potential approach towards the easy construction of inexpensive heterostructured electrocatalysts for HER activity in alkaline medium.     

建筑给水立管成环型式与水头损失消减效果研究

建筑供水系统是城镇供水体系的终端,建筑的节能节水问题一直是业界关注的热点.建筑给水管道系统多采用枝状管网,存在节能节水方法不多、最不利点水压待优化、节能节水效率不高等问题.提出了基于最不利点的建筑给水立管设置成环状观点,采用EPANET软件建立了建筑给水立管系统模型,研究了建筑给水管道系统在不同流量、不同立管成环型式的最不利点水头损失变化规律,表明建筑立管成环型式均有明显的水头损失消减作用,确定出几种典型建筑给水立管成环型式的最不利点水头损失消减效果,其中2种管网的三立管成环型式的水头损失比单立管型式分别减小27.08％和50.47％;明确了建筑给水立管成环型式的连通管长度及管径之间适配性,确定的适宜管径和最大长度分别为DN32和100?230 m.