摘要：Porous spherical MnCo_(2)S_(4) was synthesized by a simple solvothermal *** to the well-designedbimetallic composition and the unique porous spherical structure,the MnCo_(2)S_(4) electrode exhibited an exceptionalspecific capacitance of 190.8 mAh·g^(-1)at 1 A·g^(-1),greatly higher than the corresponding monometallic sulfides MnS(31.7 mAh·g^(-1))and Co_(3)S_(4)(86.7 mAh·g^(-1)).Impressively,the as-assembled MnCo_(2)S_(4)||porous carbon(PC)hybridsupercapacitor(HSC),showed an outstanding energy density of 76.88 Wh·kg^(-1)at a power density of 374.5 W·kg^(-1),remarkable cyclic performance with a capacity retention of 86.8% after 10000 charge-discharge cycles at 5 A·g^(-1),and excellent Coulombic efficiency of 99.7%.

摘要：共价有机框架材料(Covalent organic frameworks,COFs)是一种具有周期性二维或三维网状结构的多孔有机材料,其结构由两种或更多有机分子通过共价键连接而成。COFs具有骨架密度低、比表面积大、孔隙率高、结构可设计性和功能可修饰性等特点,在储能领域展现出巨大的潜力。由于其丰富的氧化还原活性位点和开放的框架结构,COFs作为金属离子电池正极材料有着独特的优势。然而COFs导电性差、能量密度低、可用的活性位点较少和离子传输通道的阻塞等缺陷限制了其在储能领域的应用。本文系统综述了COFs作为金属离子电池正极材料的最新研究现状,包括对COFs的种类、合成方法以及设计策略进行总结,从不同活性基团的角度对其电化学储能机理进行概述,并介绍了COFs在不同金属离子电池方面的应用。最后总结和展望了COFs在储能领域应用的前景和挑战。

摘要：[PO_(4)]3-possesses small microscopic secondorder susceptibility and polarizability anisotropy,which inherently result in weak second-harmonic generation (SHG)and small ***,a new noncentrosymmetric phosphate,[C(NH_(2))3]3PO_(4)·2H_(2)O,was successfully designed and synthesized by a solution evaporation method.[C(NH_(2))3]3PO_(4)·2H_(2)O without metal ions is composed of planar conjugated guanidine cations and PO_(4)tetrahedrons,which are connected by hydrogen bonds,forming a three-dimensional *** property measurements indicate that the title compound displays an SHG response of 1.5×KH_(2)PO_(4)(KDP) and a larger birefringence (0.055@546.1 nm)compared with most reported ultraviolet nonlinear optical ***,first-principles calculations reveal that theπ-conjugated planar[C(NH_(2))3]+cations and[PO_(4)]3-groups are responsible for its excellent linear and NLOproperties.

摘要：The design of highly active and stable catalysts for the oxygen evolution reaction(OER) in acidic media has become an attractive research area for the development of energy conversion and storage technologies. However, progress in this area has been limited by the poor understanding of the dynamic active structure of catalysts under realistic OER conditions. Here, an atomic Co-doped nanoporous Ru O_(2)electrocatalyst, which exhibited excellent OER activity and stability in acidic conditions, was synthesized through annealing and etching of a nanoporous Co-Ru alloy. Operando X-ray absorption spectroscopy results confirmed that the etching strategy produced abundant oxygen vacancies around the metal centers in the atomic Co-doped nanoporous Ru O_(2)electrocatalyst. These vacancies created contracted metaloxygen ligand bonds under realistic OER conditions. The dynamic structural evolution of the synthesized electrocatalyst allowed them to experience lower kinetic barriers during OER catalysis, resulting in enhanced catalytic activity and *** study also provided atomic details on the active structure of the electrocatalyst and the influence of their structural evolution on OER activity.

摘要：国防R&D是国防科技创新的源泉。国防R&D活动存在着复杂的委托代理关系,导致分摊成本和信息租金的增加。本文用委托代理理论框架对国防R&D行为主体进行激励分析,通过构建政府与军队、军队与企业在信息不对称条件下的博弈模型,揭示国防R&D活动运行的内在机理以及投资低效的深层次原因,进而对国防R&D活动激励机制进行了针对性设计,提出了一些有意义的对策性思考。

摘要：设计了以“滴”为计量单位、以微距摄影为观察方式的可视化微型化学实验。在表面皿中探究铜氨配合物、银氨配合物和铁离子配合物的形成过程,使反应空间平面化。通过智能手机和手机微距镜头的配合使用,可明晰配合物和沉淀的区别。利用投影技术,可清晰地在课堂上呈现实验过程中沉淀的生成和溶解等微观现象。制备铜氨配合物时,晶体的析出更是美不可言。改进后的实验具有可视化、微型化、安全环保等特点。

摘要：本文阐述了基于Web GIS的水利特色三维智慧校园系统的设计理念,并进一步提出构建实用、可行的水利特色智慧校园系统设计方案。以校园的三维场景尤其是特色水景观场景为基础,融合3D数据、地形数据、全景照片数据以及多媒体数据,通过Web GIS技术发布以上数据,并把数据融合在一起,为用户提供浏览、查询、分析等功能,让用户方便、快捷地了解校园信息。同时,物联网技术的应用,实时的教室监控信息,帮助学生选择合适的自习室,实现校园资源的优化使用。

摘要：我国的自然保护地普遍存在着科学管控难、统一管理难和资金供给难等问题,即便是国家公园体制试点区也不例外。本文以钱江源国家公园体制试点区为例,设计了基于细化保护需求的保护地役权制度,以探索一种能解决上述问题并能体现生态补偿的适应性管理方法,包括:细化主要保护对象的管理需求,结合土地利用类型,确定实施保护地役权的空间范围;辨析保护需求和原住民生产、生活之间的关系,形成正负行为的准则并以行为清单的形式体现;从生态系统监测指标改善情况、正负行为遵守情况和社区能力建设三个维度制定地役权制度的评价方法;据此形成地役权合同,明确供役地人和需役地人的权责利,形成考虑保护绩效的生态补偿方案。这种方法可以解决自然保护地因为权属不一致造成的生态系统和景观破碎化问题,缓解社区发展和生态保护之间的矛盾,在我国南方集体林地占比较高的自然保护地具有适用性。

摘要：In this paper, four point bending tests were carried out to investigate the flexural properties of PVA fiber reinforced engineered cementitious composites (ECC) with different mix proportions. Based on the test results, the flexural toughness was evaluated with the methods of JSCE and post crack strength method (PCSm), respectively. Several parameters such as amount of water reducer, amount of sand, and fiber volume fraction were investigated to study their effects on the flexural toughness of ECC beams. According to the test results, superfluous water reducing additions can cause adverse effect on strength of the matrix and interfacial bond between fibers and the matrix, resulting in decreased bending strength and flexural toughness of ECC beams. Increase of the fiber volume fraction can result in increased flexural strength and toughness due to enhanced bridging effect between fibers and cementitious matrix. High amount of sand can reduce ductility and strain hardening behavior of ECC material, and better flexural toughness can be achieved when the amount of sand by weight is set to 0.2 for current water/cement ratio.

摘要：从不同分类图书的构思创意入手,通过几种形式构成的方法和印刷工艺及不同材料的运用,阐述如何设计出好的书籍封面艺术作品。