摘要：Graphene-based three-dimensional （3D） macroscopic materials have recently attracted increasing interest by virtue of their exciting potential in electrochemical energy conversion and storage. Here we report a facile one-step strategy to prepare mechanically strong and electrically conductive graphene/Ni（OH）2 composite hydrogels with an interconnected porous network. The composite hydrogels were directly used as 3D supercapacitor electrode materials without adding any other binder or conductive additives. An optimized composite hydrogel containing -82 wt.% Ni（OH）2 exhibited a specific capacitance of -1,247 F/g at a scan rate of 5 mV/s and -785 F/g at 40 mV/s （-63% capacitance retention） with excellent cycling stability. The capacity of the 3D hydrogels greatly surpasses that of a physical mixture of graphene sheets and Ni（OH）2 nanoplates （-309 F/g at 40 mV/s）. The same strategy was also applied to fabricate graphene-carbon nanotube/Ni（OH）2 ternary composite hydrogels with further improved specific capacitances （-1,352 F/g at 5 mV/s） and rate capability （-66% capacitance retention at 40 mV/s）. Both composite hydrogels obtained here can deliver high energy densities （-43 and -47 Wh/kg, respectively） and power densities （-8 and -9 kW/kg, respectively）, making them attractive electrode materials for supercapacitor applications. This study opens a new pathway to the design and fabrication of functional 3D graphene composite materials, and can significantly impact broad areas including energy storage and beyond.

摘要：Electrocatalytic ammonia synthesis under mild conditions is an attractive and challenging process in the earth’s nitrogen cycle,which requires efficient and stable catalysts to reduce the *** N2 activation and reduction overpotential of different Ti3C2O2-supported transition metal(TM)(Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Mo,Ru,Rh,Pd,Ag,Cd,and Au)single-atom catalysts have been analyzed in terms of the Gibbs free energies calculated using the density functional theory(DFT).The end-on N2 adsorption was more energetically favorable,and the negative free energies represented good N2 activation performance,especially in the presence Fe/Ti3C2O2(﹣0.75 eV).The overpotentials of Fe/Ti3C2O2,Co/Ti3C2O2,Ru/Ti3C2O2,and Rh/Ti3C2O2 were 0.92,0.89,1.16,and 0.84 eV,*** potential required for ammonia synthesis was different for different TMs and ranged from 0.68 to 2.33 *** possible potential-limiting steps may be involved in the process:(i)hydrogenation of N2 to*NNH and(ii)hydrogenation of*NH2 to *** catalysts can change the reaction pathway and avoid the traditional N–N bond-breaking *** also simplifies the understanding of the relationship between the Gibbs free energy and overpotential,which is a significant factor in the rational designing and large-scale screening of catalysts for the electrocatalytic ammonia synthesis.

摘要：The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N‐heterocycles is a *** this study,Ru_(2)P/AC effectively promoted reversible transformations between unsaturated and saturated N‐heterocycles affording yields of 98%and 99%,***,a remarkable enhancement in the reusability of Ru_(2)P/AC was observed compared with other Ru‐based *** to density functional theory calculations,the superior performance of Ru_(2)P/AC was ascribed to specific synergistic factors,namely geometric and electronic effects induced by P.P greatly reduced the large Ru‐Ru ensembles and finely modified the electronic structures,leading to a low reaction barrier and high desorption ability of the catalyst,further boosting the hydrogenation and acceptorless dehydrogenation processes.

摘要：The nitrogen reduction reaction(NRR)using new and efficient electrocatalysts is a promising al‐ternative to the traditional Haber‐Bosch ***,it remains a challenge to design efficient catalysts with improved catalytic ***,various O‐functional MXenes were investigated as NRR catalysts by a combination of density functional theory calculations and least absolute shrinkage and selection operator(LASSO)***_(3)C_(2)O_(X) has been regarded as a promising catalyst for the NRR because of its stability,activity,and *** poten‐tial‐determining step is*NH_(2) hydrogenation to*NH3 with a limiting potential of-0.45 ***‐more,via LASSO regression,the descriptors and equations fitting the relationship between the properties of O‐functional MXenes and NRR activity have been *** work not only pro‐vides a rational design strategy for catalysts but also provides machine learning data for further investigation.

摘要：从控制的角度综述了多功能、高质量成像需求下,超稳定、超精确、超敏捷高分辨率光学遥感卫星精密敏捷控制的关键技术和研究进展。以卫星成像与姿态控制系统性能的关系为基础,从姿态机动能力与多功能成像、姿态确定精度与成像质量和姿态控制精度与成像质量三个方面论述了精密敏捷控制技术对光学遥感卫星成像的重要性。在此基础上,结合光学遥感卫星姿态控制系统的组成及原理,分析了影响姿态控制精度和姿态机动能力的主要因素,对高精度姿态确定、精密姿态控制和敏捷姿态控制三个关键技术方向进行了讨论和总结。最后,综合当前技术的发展趋势,围绕一体化成像控制的设计思想展望了精密敏捷控制技术未来的发展趋势,为实现高分辨率光学遥感卫星多功能、高质量成像控制提供了理论依据和工程参考。

摘要：区域性河流跨越行政边界连接着多个城镇、乡村和自然空间,河流及其沿岸具有多种生态服务功能,是自然资源保护与利用矛盾突出的地带。我国区域性河流的综合规划和管控在价值理念、规划方法和管理机制等方面存在各种问题,不利于协调国土空间生态保护与建设发展。美国较早地经历了城市化后的河流保护、修复与利用阶段,善于协调土地利用、自然水文过程与社会经济的关系,对提升我国区域性河流沿岸自然资源的保护效力和复合服务功能有着很好的借鉴价值。基于此,本文主要采用案例研究法,从规划目标和组织、核心规划方法、设计引导和管理三个方面梳理和剖析美国洛杉矶河总体规划与管控的理念和方法;并提出对我国区域性河流综合规划与管控的三点经验启示:强化多维度价值导向下河流复合功能目标的确立,将“河流标尺”工具贯穿“分析—规划—管控”全过程,采用多元主体参与的协作式管理模式衔接规划编制体系。

摘要：针对传统斜拉闸门吊杆装置存在与轨道面摩擦、增加启闭力等影响闸门安全运行的问题,研发了一种带支承轮的斜拉闸门吊杆装置,在实际工程运用中取得良好效果,可供类似工程参考。

摘要：臭氧是一种环境友好型氧化剂,可直接用于消毒、杀菌和废水处理,对于维护和促进公共卫生安全至关重要.由于臭氧容易分解,不利于储存,因此需要现制即用.目前臭氧生成技术主要包括:电晕放电法和电催化臭氧生产(EOP)技术.相较于电晕放电法,EOP是一种本质安全的臭氧生产技术.然而,该工艺相较于电晕放电技术电能消耗量大,为了使其更具商业可行性,有必要开发高活性且低成本的电催化剂.此外,合理的电解槽设计对于实现高效EOP过程也至关重要.然而,目前研究主要集中在提高EOP催化剂活性方面,对电解槽的结构设计优化的关注较少.本文通过开发高效电催化剂进而将其应用于结构优化后的电解槽中,实现了更加高效的EOP过程.本文采用水热方法成功制备了一种具有较高EOP活性的方形氧化铅(PbO_(x)-CTAB-120)电催化剂.在标准三电极测试系统中,电流密度为50 mA cm^(-2)的测试条件下,法拉第效率(FE)可达20.7%,与商用β-PbO_(2)(17.1%)相比提高了21.1%.此外,设计了具有平行流场的可视化EOP电解槽,该可视化电解槽在传质和传热方面具有明显优势,有利于实现更加高效的EOP过程.将催化剂PbO_(x)-CTAB-120组装至可视化电解槽中,在1.0 A cm^(-2)的测试电流密度下,电解液为超纯水,该体系气态臭氧产量可以达到588 mg h^(-1)g^(-1)catalyst,比能量消耗(PEOP)为56 Wh g^(-1)gaseous ozone.体系臭氧产量约为商用β-PbO_(2)在传统电解槽中产量的2倍,并且PEOP降低率超过62%.原位18O同位素标记差分电化学质谱和密度泛函理论计算结果表明,PbO_(x)-CTAB-120电催化剂在EOP过程中遵循晶格氧机理路径,晶格氧迁移产生的氧空位能有效稳定OOH^(*)和O_(2)^(*)反应中间体,因此有利于催化剂在EOP过程中保持较好的反应活性和稳定性.同时,还利用先进的高速摄像可视化工具和计算流体力学(CFD)仿真模拟研究了平行流场EOP电解槽的运行过程和高效传质传热的原理.CFD模拟结果表明,与传统流场模型相比,平行流场对应的出口气泡停留时间更长,说明平行流场更有利于产物气泡从出口逸出,即气泡容易快速扩散,与实验结果一致.因此,PbO_(x)-CTAB-120电催化剂与新型可视化电解槽相结合,有助于在超纯水中实现较好的气态臭氧产率和较低比能耗.此外,二者的结合充分发挥了电催化剂的EOP活性和电解槽的传质特性所带来的优势,实现了反应性和传输性的协同增强,从而极大促进了原位有机污染物降解效率.综上所述,本文在制备高效阳极催化剂的基础上,同时利用优化电解槽结构实现了提升臭氧产率和降低过程能耗,为高活性电催化剂与优化的电解槽耦合以实现高效EOP过程及其有效应用提供参考.

摘要：非正规绿地中居民自发的果蔬种植行为长期困扰社区空间治理,个体种植行为影响社区公众利益构成焦点问题。如何趋利避害,将非正规绿地中的自发种植空间转化为社区公共服务产品产出场所,适应非正规绿地自发种植空间内在机理与现实问题的空间设计策略值得研究。通过自发种植行为实地调研,发现非正规绿地的“阈限性”特征和弱势群体的空间诉求是引发非正规种植行为、产生负外部性影响的根本原因。进而推倒得出“明确空间功能”,促进“多元化主体参与”和“复合功能共享”的负外部性治理思路。借鉴食物森林理论,通过理论调适应用于非正规绿地自发种植空间,从而形成适应中国社区非正规绿地本底环境的“社区食物微森林”复合功能公共产品输出路径,从“食物+生态、景观、休闲”复合功能的微森林营造技术和长效治理机制两方面,有效回应了我国非正规绿地的现状问题与社区本底环境诉求,对社区非正规绿地自发种植空间治理具有参考价值。

摘要：针对变电站防误系统仅考虑一次设备防误的管控策略难以控制变电站现场作业风险的问题,提出适应“运检一体化”模式的变电站多元融合全站域智能防误系统设计方案。该系统在原有微机防误技术的基础上,通过电子模拟图板软件整合站内各部分数据孤岛,实现了变电站锁控、一二次设备统筹防误以及安全工器具管理的全站域安全管控;将防误理念拓展到二次设备操作防误、检修作业防误和运维作业防误;完成了各类操作的可视见、可干预、可追溯,能够控制变电站现场作业风险,实现了全站域的业务共享和数据融合。