摘要：采用两步法将PtNi合金与二维金属碳化物Ti3C2 MXene有效复合,制备了一种用于质子交换膜燃料电池的氧还原反应(ORR)催化剂。以层状三元金属碳、氮化物(MAX)为原料,采用氢氟酸刻蚀制得MXene,再通过插层处理来获得超薄片状结构MXene材料。MXene可以吸附Pt和Ni的前驱体并锚定铂镍纳米颗粒,防止其在高温形成合金时团聚。通过将退火温度调整为500,700和900℃得到PtNi/MXene-500,PtNi/MXene-700和PtNi/MXene-900纳米复合材料。电化学研究表明:与PtNi/MXene-500相比,PtNi/MXene-700电催化剂的合金相比例更高,Pt的晶格收缩程度更大,表现出更高的催化活性;与PtNi/MXene-900相比,PtNi/MXene-700电催化剂粒径较小、电化学活性面积较大,电化学性能较好。因此,PtNi/MXene-700电催化剂在酸性介质中的半波电位为0.8970 V,质量活性为410.4 mA·mg^(-1);在碱性介质中半波电位为0.8947 V,质量活性为272.1 mA·mg^(-1),表现出较高的氧还原催化性能。

摘要：Rational design and controllable synthesis of efficient electrocatalysts for water oxidation is of significant importance for the development of promising energy conversion systems, in particular integrated photoelectrochemical water splitting devices. Cobalt oxide(Co3O4) nanostructures with mixed valences(Ⅱ,Ⅲ)have been regarded as promising electrocatalysts for the oxygen evolution reaction(OER). They are able to promote catalytic support of OER but with only modest activity. Here, we demonstrate that the OER performance of cubic Co3O4 electrocatalyst is obviously improved when they are anchored on delaminated two-dimensional(2D) Ti3C2 MXene nanosheets. Upon activation the overpotential of the hybrid catalyst delivers 300 m V at a current density of 10 m A cm(2) in basic solutions, which is remarkably lower than those of Ti3C2 MXene and Co3O4 nanocubes. The strong interfacial electrostatic interactions between two components contribute to the exceptional catalytic performance and stability. The enhanced OER activity and facile synthesis make these Co3O4 nanocubes-decorated ultrathin 2D Ti3C2 MXene nanosheets useful for constructing efficient and stable electrodes for high-performance electrochemical water splitting.

摘要：本文介绍了武钢职工培训管理系统的功能、特点.就送培人数的分解存储问题,从系统设计的角度进行了讨论.并对系统中固定汉字串的快速录入和报表生成器的使用技术进行了说明.

摘要：广东惠州新世界长湖苑居住小区是利用外资开发的大型安居工程。小区位于惠州市新开河东岸,与惠州旧市区仅一河之隔,北面紧邻324国道即广汕公路,南濒西枝江,50米的城市规划道路从小区中穿过,交通极为便利。小区总规划用地面积为31.8公顷,现以小区50米规划路为界将小区分为A区和B区两部分,其中A区为居住区用地。

摘要：成本控制是企业长久发展的命脉所在,一个工程项目从立项到完成需经过多个阶段,比如立项审批阶段、立项可研阶段、初步设计阶段、设计阶段、招投标阶段、施工阶段和竣工结算阶段等。每一个阶段都有它独特的计价方式和成本控制方法。因此,每一个环节都对成本有不同程度的影响。通过阐述工程项目各个阶段的管理和控制内容,提出了有效降低工程成本和合理控制投资规模的措施,以供相关单位参考。

摘要：The development of efficient electrocatalysts for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) with excellent catalytic performance and stability plays key roles in the commercialization of water splitting to generate hydrogen energy. Herein, a 2 D-3 D nanostructure composed of metal hydroxides and Prussian blue analogus(PBA) was in-situ decorated onto the Ni Fe foam(Pt-Ni Fe PBA) through a facile and scalable corrosive-coordinate approach. The specifically designed morphology favored the provision of abundant active sites, optimized the reaction pathway, and accelerated mass transport during the electrocatalytic process. Consequently, the as-synthesized Pt-Ni Fe PBA reached 10 m A cm^(-2) with small overpotentials of 29 and210 m V in 1 mol L;KOH deionized water for HER and OER,respectively. Remarkably, Pt-Ni Fe PBA required an overpotential of 21 m V to drive 10 m A cm^(-2) in seawater containing1 mol L;KOH with prominent durability. Moreover, with the as-synthesized Pt-Ni Fe PBA as bifunctional electrocatalyst,the Pt-Ni Fe PBA||Pt-Ni Fe PBA electrolyzer needed 1.46 and1.48 V to drive 10 m A cm^(-2) in 1 mol L;KOH with deionized water and 1 mol L;KOH with seawater, respectively. Remarkably, sustainable energies were utilized to power the overall water splitting and stored as easily portable hydrogen energy.

摘要：介绍了双轴式等分槽专用铣床的总体布局设计、机床加工循环方法、机床主要技术参数、液压系统和自动分度机构的工作原理及设计注意事项。

摘要：对军工产品用6070-T6铝合金的生产工艺进行了研究。从模具设计、挤压工艺、时效制度等因素进行综合选择,生产出了满足客户力学性能要求(σ_(b)≥340 MPa,σ_(0.2)≥310 MPa,δ_(5)≥8%)的大截面薄壁产品。在本研究的工艺条件下,T6态铝合金的抗拉强度、屈服强度和延伸率可达377 MPa、341 MPa和12.5%。

摘要：随着“互联网+公交智慧出行”新业态的快速发展,大数据在公共交通领域逐步深入应用,提高了公交网络宏观决策的科学性和高效性,方便了企业营运部门对不合理的公交线网布局、运营组织模式的优化管理。本文以昆明公交数据大脑分析应用为例,阐述了目前公交大数据基础、主要分析系统以及数据分析成果的应用场景。同时,重点介绍了大数据分析的应用实例,启发后续公交线网优化设计方案,为进一步挖掘大数据的分析应用奠定基础。

摘要：水利工程是国家基础设施建设的重要组成部分,水利工程的建设会影响到周围地区的发展。因此,为了使水利工程建设顺利进行,充分应用遥感遥测技术就显得尤为重要。遥感遥测技术可以有效提高勘测效率和质量,减少工作人员工作量。对多元遥感数据进行分析,可以获得准确的水文、地质、生态等信息,还可以通过建筑信息模型(building information modeling, BIM)技术对工程建设后的效果、影响、灾害防治等进行有效预测。对水利工程勘测设计中的遥感遥测技术应用进行分析,对遥感遥测技术进行综述,对遥感遥测技术在田庄水库可研阶段的实际应用以及在其他方面的应用进行分析,以供参考与借鉴。