摘要：Untreated urea-rich wastewater exerts severeadverse impacts on both the environment and human health,prompting extensive attention towards the urea oxidationreaction (UOR) as a sustainable technology to generate cleanenergy in recent years. UOR has a thermodynamic advantageover oxygen evolution reaction (OER) (1.23 V vs reversiblehydrogen electrode, RHE) and only requires 0.37 V (vs RHE),which is considered as an effective alternative to H_(2) production by water electrolysis. However, the inevitable kineticslowness and complex adsorption/desorption during the processhinder its practical application. Most traditional catalystsutilized for the UOR are comprised of precious metals, resulting in limited economic viability. Inspired by natural ureases, Ni-based catalysts have emerged as promisingalternatives owing to their rich deposits, low cost, and theregulated d orbitals of transition metal Ni, demonstratingconsiderable potential for UOR. Currently, numerous studieshave explored Ni-based hydroxides, oxides, chalcogenides, andphosphides in alkaline solutions. In this review, we will explorethe UOR reaction mechanism and summarize the catalystdesign strategies of various Ni-based catalysts recently, especially Ni-MOF, which has been rarely discussed before. Then,the broad prospects of UOR in practical applications aresummarized. Finally, based on the design strategies and performance comparisons discussed above, the challenges andprospects facing the future development of Ni-based electrocatalysts for the UOR will be presented.

摘要：Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable ***,existing research is focused on the effects of structural phase transitions on photophysical properties,and lacks in-depth understanding of the mechanisms of self-trapped excitons ***,we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition,resulting in a substantial increase in photoluminescence(PL)quantum yield from 3.5%to 91.4%.In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination,demonstrating the introduction of rich lattice distortion during the dehydration ***-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy,facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state,corresponding to the enhanced emission *** a proof of concept,several switchable PL applications have been established in scenarios such as anti-counterfeiting,rewritable luminescent paper,and humidity *** finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.

摘要：Traditional 3Ni weathering steel cannot completely meet the requirements for offshore engineering development,resulting in the design of novel 3Ni steel with the addition of microalloy elements such as Mn or Nb for strength enhancement becoming a *** stress-assisted corrosion behavior of a novel designed high-strength 3Ni steel was investigated in the current study using the corrosion big data *** information on the corrosion process was recorded using the galvanic corrosion current monitoring *** gradi-ent boosting decision tree(GBDT)machine learning method was used to mine the corrosion mechanism,and the importance of the struc-ture factor was *** exposure tests were conducted to verify the calculated results using the GBDT *** indic-ated that the GBDT method can be effectively used to study the influence of structural factors on the corrosion process of 3Ni ***-ferent mechanisms for the addition of Mn and Cu to the stress-assisted corrosion of 3Ni steel suggested that Mn and Cu have no obvious effect on the corrosion rate of non-stressed 3Ni steel during the early stage of *** the corrosion reached a stable state,the in-crease in Mn element content increased the corrosion rate of 3Ni steel,while Cu reduced this *** the presence of stress,the increase in Mn element content and Cu addition can inhibit the corrosion *** corrosion law of outdoor-exposed 3Ni steel is consistent with the law based on corrosion big data technology,verifying the reliability of the big data evaluation method and data prediction model selection.

摘要：Field observations illustrated that, right-turn vehicles stopped at various positions when proceeding within the right-turn lanes, while some of them trespassed on the crosswalks with multiple stops. In this case, pedestrians and bikes (ped/bike) are encountered unsmooth and hazardous crossings when right-turn vehicles encroaching their lanes. Meanwhile, this also causes conflicts between right-turn and through vehicles at the crossing street. To better protect ped/bike at crossings with right-turn vehicles, this paper proposes a concept of “right-turn vehicle box” (RTVB) as a supplemental treatment within right-turn lanes. Sight distance, geometric conditions, and behaviors of vehicles and ped/bike are key factors to consider so as to set up the criteria and to design the suitable treatment. A case study was conducted at an intersection pair in Houston, USA to shape the idea of RTVB, together with driving simulator tests under relevant scenarios. The preliminary crosscheck examination shows that the right-turn vehicle box could possibly provide ped/ bike with smoother and safer crossings. In the interim, the safety and efficiency of right-turn operations were also improved. To further validate the effects, implementation studies should be conducted before the RTVB can make its debut in practice. Future works will focus on the complete warrants and design details of this treatment. Moreover, the concept of “vehicle box” could also be transplanted to other places where turning movement(s) needs assistance or improvements.

摘要：We report a facile way to prepare sulfur(S) doped Ni4/5 Fe1/5-layered double hydroxide(LDH) electrocatalysts for oxygen evolution reaction(OER). The influence of S doping amount on the OER activity of the resulted Ni Fe-LDHs was studied and the optimal surface S content was ca. 0.43 at%. The developed S-doped Ni Fe-LDH exhibits excellent OER catalyst activity in 1.0 M KOH with overpotential of only 257 m V at the current density of 10 m A cm^-2. Moreover, the catalyst could maintain high activity after 30 h stability test. The high activity of the S-doped Ni Fe-LDH catalysts may originate from the synergistic effect between S and the Fe sites. This work provides a simple but efficient way to improve the OER performance of transition metal oxides/(oxy)hydroxides.

摘要：Tracking the process of fault growth in mechanical systems using a range of tests is important to avoid catastrophic failures, So, it is necessary to study the design for testability （DFT）. In this paper, to improve the testability performance of me- chanical systems for tracking fault growth, a fault evolution-test dependency model （FETDM） is proposed to implement DFT. A testability analysis method that considers fault trackability and predictability is developed to quantify the testability performance of mechanical systems. Results from experiments on a centrifugal pump show that the proposed FETDM and testability analysis method can provide guidance to engineers to improve the testability level of mechanical systems.

摘要：针对现阶段水肥一体化设备存在施肥不均、自动化程度不高及滞后性严重的问题,根据现代化农业节水省肥和减少环境污染的灌溉要求,设计了一款可实现自动混肥、施肥、节水灌溉的主路式水肥一体化施肥机。根据液肥的EC和pH值调节过程的特点,开发了以SIEMENS S7-1200为核心的液肥控制系统硬件,并结合MatLab设计了以模糊PID为控制器的液肥EC和pH值控制系统。为验证施肥机在实际应用中的精确性和鲁棒性,设计了施肥系统动态调节性能试验,结果表明:在施肥阶段,模糊PID控制系统具有较短的稳态时间和较小的超调量,相比于PID控制系统,对EC和pH值进行调节的稳态时间分别减少了37.7%和52.1%,稳态超调量分别降低了1.2%和2.2%,可实现对混肥溶液进行迅速有效的调节,满足现代农业实际生产需要。

摘要：为了延长网络的生存时间,需要设计能量有效的协议,以适应传感器网络的特点.成簇算法是传感器网络中减少能量消耗的一种关键技术,它能够增强网络的扩展性和延长网络的生存时间.研究了异构传感器网络中成簇算法在节省能量方面的性能,提出一种适应异构无线传感器网络的分布式能量有效的成簇方案.此方案基于节点剩余能量与网络节点的平均能量的比例来选举簇头节点.较高初始能量和剩余能量的节点比低能量节点拥有更多的机会成为簇头节点,从而使网络能量均匀消耗,延长网络的生存时间.模拟实验结果显示,与现有的重要成簇方案相比,新的成簇算法在异构网络下提供了更长的网络生存时间和更大的网络有效吞吐量.

摘要：质子交换膜燃料电池(PEMFC)具有高转化效率、高功率密度以及低污染等优点,目前受到广泛关注。燃料电池的性能主要受限于阴极的氧还原反应,其成本也受限于阴极催化剂。目前人们已经设计了许多策略、开发了许多催化剂,特别是铂基合金催化剂,来加快氧还原反应的速率,提高燃料电池性能。然而,由于过渡金属的溶解以及纳米粒子的团聚等问题,氧还原催化剂以及燃料电池的长效稳定性仍然存在问题。如何设计高效、高稳定的燃料电池阴极催化剂,对于进一步推动燃料电池的应用十分关键。针对燃料电池阴极催化剂稳定性的问题,本文综述了近年来提升燃料电池铂基催化剂稳定性的原理、策略与方法,首先我们从热力学和动力学上阐述影响催化剂稳定性的原因及其调控原理。随后,我们将概述一些具有代表性的提升催化剂稳定性的策略和方法。最后,我们对未来发展方向进行了总结与展望。

摘要：开发用于氧还原反应(ORR)的高性能Pt-M(M=过渡金属)金属间合金催化剂是实现质子交换膜燃料电池(PEMFC)大规模应用的关键.因此迫切需要明确设计和制备具有高ORR活性和稳定性的金属间Pt-M催化剂的一般规则.本文首先概述了无序-有序相变的热力学和动力学基本原理,然后介绍了本课题组在合成L10有序结构的Pt-M金属间纳米晶(iNC)方面的研究结果,进一步阐述了提高L10-Pt-M燃料电池ORR催化剂的活性和稳定性的有效策略.关于铂基金属间纳米晶的合成,本课题组基于高温相变扩散动力学发展了空位介导原子扩散的方法用于合成全有序铂基金属间纳米晶.铂基金属间纳米晶通常是通过高温退火制得,但该过程中原子的快速扩散会加剧奥斯特瓦尔德熟化和材料烧结,进而导致催化剂活性下降.对纳米晶进行包覆或者限域虽然能够在一定程度上降低高温退火过程中的颗粒团聚,但是原子扩散受限也导致难以获得完全有序的纳米晶.空位扩散是金属纳米晶有序转变过程中的主要扩散过程,可以在退火前驱体中构建Pt/MO_(x)界面.本课题组发展了空位介导原子扩散促进铂基合金有序化的方法,制得了一系列用于ORR反应的超细Pt-M(M=Fe,Co,Ni,Zn等)金属间纳米晶催化剂,实现了铂基金属间纳米晶的高效制备.关于铂基金属间纳米晶催化剂的活性调控,本课题组基于应变效应的调控策略开发了多种具有高氧还原活性的铂基金属间纳米晶催化剂.根据理论预测的铂表面最佳氧物种吸附能,通过掺杂钨原子调控表面应变,有效削弱了L1_(0)-PtCo纳米晶表面的过度应变,制得的催化剂表现出良好的催化活性.此外,介绍了双轴应变介导的高活性L1_(0)-PtZn/Pt-C催化剂,独特的表面应变模式使其在氧还原反应中表现出较好的催化活性,并在燃料电池器件中表现出较好的质量活性与功率密度.关于铂基金属间纳米晶催化剂稳定性的提升,本课题组基于腐蚀热力学与热力学原理发展了多种提升金属间纳米晶催化剂稳定性的方法.铂基金属间纳米晶组元间独特的强轨道相互作用在提升催化稳定性方面表现出明显优势,基于此,开发了具有强Pt(5d)-Ni/Co(3d)相互作用的C-L1_(0)-PtNi_(0.8)Co_(0.2)催化剂,其在加速稳定性测试后表现出良好的稳定性.此外,根据稳定表面的纳米表面工程方法,制备了低表面能的L10-W-Pt Co纳米晶,该催化剂在燃料电池测试中表现出较好的稳定性.针对催化剂的溶解腐蚀,本课题组开发了具有高表面空位形成能的L1_(0)-PtZn/Pt-C催化剂,有效降低了催化剂在燃料电池中的性能衰减,并且通过理论计算,揭示了金属间相结构热力学参数(形成能)与腐蚀过程动力学参数(空位形成能)的相关关系,有望为后续开发高稳定性铂基氧还原催化剂提供理论参考.综上,本文为未来应用于PEMFC和其他电化学能量转换技术的Pt-M金属间合金ORR催化剂的研究和开发提供一些借鉴.