摘要：Tandem electrocatalysis is an emerging concept for effective electrochemical CO_(2) reduction reaction(CO_(2)RR)towards multicarbons(C_(2+)).This decouples the multiple steps of CO_(2)-to-C_(2+)into two steps of CO_(2)-to-CO and CO-to-C_(2+)catalyzed by individual catalysts,to improve the Faradic efficiency(FE).However,due to the mass-transport limitation of CO from the generation site to the long-distance consumption site,such a strategy still remains challenge for high-rate production of C_(2+)***,we designed CuO/Ni single atoms tandem catalyst,which made the catalytic sites of Ni and Cu for independently catalyzing CO_(2)-to-CO and CO-to-C_(2+)compactly neighbored,enabling the in-situ generation and rapid consumption of *** CuO/Ni SAs tandem catalyst achieved a particularly high partial current density of C_(2+)products(1220.8 mA/cm^(2)),while still maintained outstanding C_(2+)products FE(81.4%)and excellent selectivities towards ethylene(FE 54.1%)and ethanol(FE 28.8%),enabling the profitable production of multicarbons by CO_(2)RR.

摘要：The effects of cation ordering and surface compensating anions on the magnetic structure and catalytic properties of unilamellar Ni-Fe hydroxide nanosheets are studied by using the density functional theory （DFT） plus U method. Fe-segregation in the nanosheets yields magnetic domains with different spin alignments, while the surface compensating anions affect the local moments and valence states of the Fe atoms. The two conditions do not radically change the super-exchange nature of interactions between the paramagnetic metal centers, hut facilitate the formation of various magnetic superlattices in the nanosheets. The calculated free energy change of the intermediates shows that the most stable magnetic structure of Ni-Fe hydrox- ide nanosheets exhibits superior catalytic activity towards oxygen reduction/evolution reactions, which is indicative of magnetic catalyst. This is due to the cycle transition between Fe2＋ and Fe~~ ions in the reactions, which determines the sequence of cleavage of the O-H bond and the release of the OH group, controlling the rate-limiting steps of the reaction. The relationship of magnetism and catalytic activity of Ni-Fe hydroxide nanosheets is established by the valence state change of the Fe ions, which will be helpful to open the way for the design of hydroxide/layered double hydroxides （LDHs）-based magnetic catalysts.

摘要：Photocatalytic water splitting with simultaneous degradation of organic pollutants is an effective strategy to alleviate the increasingly serious energy and environmental ***,the photocatalytic activity is restricted by the high charge recombination rate and limited sunlight ***,black phosphorus(BP)with a broad sunlight response range was utilized as a photosensitizer to enhance the photocatalytic performance of the Au/carbon nitride(CN)*** as-prepared BP/Au/CN exhibited a significantly enhanced H_(2) generation rate of 1400.8µmol h^(−1) g^(−1) under UV-vis light irradiation,which is almost 70 times higher than that of bare CN and BP/CN and 2 folds higher than that of the Au/CN ***,the optimal BP/Au/CN sample presented a waste-to-hydrogen production rate of 195.8µmol h^(−1) g^(−1) with the degradation of bisphenol A,verifying the synergistic effect of the ternary *** photocatalytic mechanism was systematically studied by the combination of experiments and theoretical *** improved photocatalytic performance was derived from the overall sunlight absorption ability of BP,effective electron transfer media and plasmonic character of Au nanoparticles,as well as the matched work function and strong interaction of the three components.A unidirectional electron transfer from BP to Au and then to CN was established,which effectively improved the charge transfer capability,resulting from the appropriate Ohmic contact of Au and BP and the Schottky barrier constructed in Au/CN hybrid.

摘要：以赣江公铁两用大桥西支主桥设计为例,研究一种适应上层8车道公路、下层对称双线铁路+4车道公路混合布置的主梁断面形式。提出带挑臂双索面箱桁组合断面、带挑臂单索面箱桁组合断面、矩形箱桁组合断面、矩形钢桁梁断面4种主梁断面方案,采用有限元软件分析各方案静动力性能及受力特点,综合考虑方案构造特点、技术指标、工程数量、公铁运营安全、景观效果等,确定该桥选用带挑臂双索面箱桁组合断面。该桥斜拉索最大索力16000 kN,锚固在下层钢箱梁两侧,通过有限元实体分析对锚拉板和钢锚箱式两种索梁锚固形式进行比选研究,钢锚箱形式受力合理、应力水平低、经济性好,设计采用钢锚箱形式。带挑臂双索面箱桁组合断面桥面空间布置合理、下层公铁行车干扰小、梁端竖向变形最小、经济性好,是一种适应公铁混合布置大跨度斜拉桥主梁断面形式。

摘要：目前个人简历实体类型繁多,大量平面实体和嵌套实体交错在简历中,对实体识别产生了不小的负面影响。为此,设计了一种联合预测的命名实体识别框架。首先,利用预训练模型Mengzi-BERT进行上下文的词嵌入表示。为了充分利用预训练模型提取的特征,先对网络深度进行压缩,放大卷积层感受野,并且融合了自注意力机制,然后设计了一个新的命名实体识别模型TPDCA(triple layers progressive dilated convolutional neural network-attention)。其次,为防止实体之间跨度过大、简历实体嵌套等问题,设计了全新的基于Biaffine双仿射注意力机制的局部关系实体识别模型BCN(biaffine-based local relationship capture network)。最后,通过分别调整TPDCA模型和BCN局部关系识别模型的预测权重进行联合预测,构成Mengzi-TPDCA-CRF-BCN联合预测框架,获得了综合表现最佳的实体识别结果。这样设计避免了模型丢失实体间长距离依赖关系,降低了平面实体和嵌套实体相互交错对预测的负面影响,解决了实体类型间的高耦合度影响识别任务的问题。该模型与现行主流方法相比各评价指标提升了3%,有效地解决了简历实体类型间耦合度高,实体间跨度大的实际问题。

摘要：昌九高铁扬子洲赣江公铁大桥西支主桥采用竖琴形索面箱桁组合梁斜拉桥,跨径布置为(48+144+320+144+48)m。根据桥梁结构特点,针对花瓶形、H形和钻石形桥塔方案,从结构受力、景观效果、施工难度、经济性等方面进行比选,最终采用适应宽主梁、竖琴形索面的花瓶形桥塔。2座桥塔高度分别为143.5 m和147.1 m,采用C50钢筋混凝土结构,由上、中、下塔柱组成,塔柱圆弧过渡,设上、下2道横梁,下横梁采用预应力混凝土结构,上横梁由2道反向圆弧的预应力混凝土小横梁和中间的装饰性钢结构共同组成“昌”字造型。索塔锚固区采用钢锚箱锚固体系与预应力锚固体系相结合的方式。桥塔下塔柱采用翻模法施工,中、上塔柱外部采用爬模法施工、内部采用翻模法施工。对桥塔进行整体静力、局部应力、稳定性及抗震分析,结果表明桥塔强度、刚度、稳定性及抗震性能均满足规范要求。

摘要：现有的单元式超前液压支架在设计时没有考虑防冲击功能,当煤矿井下突发冲击地压且冲击载荷达到单元式超前液压支架最大承载力时,单元式超前液压支架无法抵抗突如其来的强大冲击载荷,由于动态响应时间不足,卸压安全阀根本来不及打开,从而造成单元式超前液压支架的立柱千斤顶出现弯曲、断裂和爆缸等现象,严重影响巷道的正常支护。为了解决这些问题,设计了一种新型可伸缩吸能防冲单元式超前液压支架,采用单轨吊外运搬移方式,在不降低承载力的情况下兼顾吸能防冲击功能并且可伸缩,方便实现往复支护巷道的功能。

摘要：针对露天矿山车载终端通信的需求,文章基于山字型结构设计一款同时满足4G/5G通信的全向偶极子天线。基于双锥天线模型设计全向印刷偶极子单频天线,通过在两侧加载枝节引入高频谐振,并通过在倒三角辐射贴片上开L形缝隙和矩形缝隙实现频段的展宽及谐振频点的偏移;对两侧枝节的末端进行渐变处理,使天线的谐振频率在拐点处可以平滑地过渡,从而在较宽的频带内获得良好的阻抗匹配。仿真和实测结果表明,该天线具备双频段全向的辐射特性,完全满足设计要求,且结构简单小巧、容易安装、不易受到损坏。

摘要：针对轨道交通工程的建筑信息模型(building information modeling,BIM)建模方法不统一、信息不规范,导致BIM模型数据难以在后期有效统一应用的弊端,研究基于工业基础类(industry foundation classes,IFC)标准的轨道交通BIM构件标准库。首先,根据轨道交通工程各专业构件的表达需求,研究构件类型、构件信息的IFC表达,以及适配IFC标准的扩展机制;其次,提出轨道交通BIM构件标准库技术框架,主要包括基础数据层、技术支撑层、应用场景层、用户层;然后,采用国家标准的分类编码方法定义轨道交通各专业BIM构件的分类编码,设计了构件信息模板,规范各专业构件的属性信息及其资源链接方式;最后,研究BIM构件模型的加解密方法,以保障轨道交通工程BIM模型数据的安全性。研究结果表明,通过搭建统一的BIM构件标准库,能够促进参建方采用标准化的BIM构件模型创建轨道交通BIM项目模型,保障BIM模型的规范性。

摘要：以多源异构军事数据组织管理的难点和技术需求为切入点,基于元数据技术实现对军事数据资源的发现、访问和理解以及对非结构化军事数据的融合利用。明确军事数据流转过程中的人员角色及其职责范围,设计军事元数据体系和层级结构,提出基于元数据的军事数据组织管理框架,明确军事数据组织管理流程并构建军事元数据管理原型系统。兼具工具性和数据性双重特征的元数据为军事数据组织管理提供了技术思路和解决方案,为军事数据高效共享利用奠定了基础。