Recent advances in cobalt phosphide-based materials for electrocatalytic water splitting:From catalytic mechanism and synthesis method to optimization design

Electrochemical water splitting has long been considered an effective energy conversion technology for trans-ferring intermittent renewable electricity into hydrogen fuel,and the exploration of cost-effective and high-performance electrocatalysts is crucial in making electrolyzed water technology commercially viable.Cobalt phosphide(Co-P)has emerged as a catalyst of high potential owing to its high catalytic activity and durability in water splitting.This paper systematically reviews the latest advances in the development of Co-P-based materials for use in water splitting.The essential effects of P in enhancing the catalytic performance of the hydrogen evolution reaction and oxygen evolution reaction are first outlined.Then,versatile synthesis techniques for Co-P electrocatalysts are summarized,followed by advanced strategies to enhance the electrocatalytic performance of Co-P materials,including heteroatom doping,composite construction,integration with well-conductive sub-strates,and structure control from the viewpoint of experiment.Along with these optimization strategies,the understanding of the inherent mechanism of enhanced catalytic performance is also discussed.Finally,some existing challenges in the development of highly active and stable Co-P-based materials are clarified,and pro-spective directions for prompting the wide commercialization of water electrolysis technology are proposed.

Construction of Split-Plot Designs with General Minimum Lower Order Confounding

Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.

Structural design for electrocatalytic water splitting to realize industrial-scale deployment: Strategies, advances, and perspectives

The green hydrogen generation powered by renewable electricity promises the potential decarbonization of the hard-to-abate sector and is essential for the fulfillment of the Paris Agreement that attempts to limit the global average temperature rise in the range of 1.5–2.0 ℃ above the pre-industrial level by the end of this century. Tremendous efforts have been devoted to the optimization of the electrocatalytic performance of the catalysts under industrial-relevant current densities via rational structure design,which induces a preferential electron distribution that favors the adsorption/desorption behavior of the key intermediates, thus accelerating the reaction kinetics. In this review, a brief introduction of the current energy status will be first presented to necessitate the importance of green hydrogen.Followed by the basic concepts and fundamental understanding of the reaction mechanisms, we present efficient strategies for the enhancement of the electrocatalytic performance of the catalysts to meet the rigorous requirement under industrial conditions and the in-depth understanding behind the reinforcement will be briefly discussed next. Then the recent advances regarding the rational design of electrocatalysts operating at an industrial scale will be summarized. Finally, the challenges and perspectives in this thriving field will be proposed from our point of view.

Interleaved-Connected Split Planar Resonant Inductor Design in 1 kV SiC LLC Converters

Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inductor helps to provide symmetrical resonant current by symmetrical impedance,and improves the distortion of resonant current,which ensures the efficiency of the whole converter.An interleaved winding connecting scheme improves the power density of the planar magnets,which contributes to power density improvement.Design method and calculation process of such split planar resonant inductor are provided.To verify the feasibility of the proposed design method,a 1 kV/48 V 6.6 kW,210 k Hz SiC LLC prototype was built,and the experimental results are given.

Design and operando/in situ characterization of precious-metal-free electrocatalysts for alkaline water splitting

Electrochemical water splitting has attracted considerable attention for the production of hydrogen fuel by using renewable energy resources.However,the sluggish reaction kinetics make it essential to explore precious-metal-free electrocatalysts with superior activity and long-term stability.Tremendous efforts have been made in exploring electrocatalysts to reduce the energy barriers and improve catalytic efficiency.This review summarizes different categories of precious-metal-free electrocatalysts developed in the past 5 years for alkaline water splitting.The design strategies for optimizing the electronic and geometric structures of electrocatalysts with enhanced catalytic performance are discussed,including composition modulation,defect engineering,and structural engineering.Particularly,the advancement of operando/in situ characterization techniques toward the understanding of structural evolution,reaction intermediates,and active sites during the water splitting process are summarized.Finally,current challenges and future perspectives toward achieving efficient catalyst systems for industrial applications are proposed.This review will provide insights and strategies to the design of precious-metalfree electrocatalysts and inspire future research in alkaline water splitting.

Splitting Balanced Incomplete Block Designs with Block Size 2×k

This paper investigated the existence of splitting balanced incomplete block designs with blck size 2× k .The necessary conditions for such a design are λ(v-1) ≡0(mod k ),and λv(v- 1)≡0(mod 2 k 2).It will show that the above necessary conditions are also sufficient for k =3 with the definite exception( v,λ )=(10,1) and with several possible exceptions.

基于Geomagic Design X组合体的逆向建模

Geomagic Design X软件常用于STL面片的逆向建模,选取一典型组合体对其逆向建模,通过对组合体对齐、分割领域、创建面片草图、创建实体和扫掠完成实体建模,最后验证体偏差检测是否符合要求,为后续相似零件的逆向建模提供参考。

Joint Transceiver Designs for Full-Duplex MIMO SWIPT Systems Based on MSE Criterion

For the simultaneous wireless information and power transfer(SWIPT), the full-duplex MIMO system can achieve simultaneous transmission of information and energy more efficiently than the half-duplex. Based on the mean-square-error(MSE) criterion, the optimization problem of joint transceiver design with transmitting power constraint and energy harvesting constraint is formulated. Next, by semidefinite relaxation(SDR) and randomization method, the SDRbased scheme is proposed. In order to reduce the complexity, the closed-form scheme is presented with some simplified measures. Robust beamforming is then studied considering the practical condition. The simulation results such as MSE versus signal-noise-ratio(SNR), MSE versus the iteration number, well prove the performance of the proposed schemes for the system model.

Mixing ratio design of emulsified asphalt cold recycled mixture based on gyratory compaction molding

In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting strength, stability and water stability test;the design of the experiment involved changing gyration number, emulsified asphalt and water content, molded specimen temperature and other factors to analyze the volume parameters, mechanical properties and water stability. The results show that both the maximum dry density and dry and wet splitting strength ratio(DWSSR) of emulsified asphalt cold reclaimed mixture are improved by the rotary compacting method, while the porosity and the optimal dosage of water are reduced. Furthermore, with the increase of compaction times, the porosity and splitting strength index both change exponentially. DWSSR and porosity are consistent with quadratic functions. The use of gyratory compaction for 70 times at 25 °C and the optimum dosage of emulsified asphalt can be determined based on the splitting strength ratio. The high-temperature stability and water damage resistance of the pavement can be improved by the use of rotary compacting method effectively, and the early strength and road performance are higher than the regulatory requirements.

Influence of Surrounding Structures upon the Aerodynamic and Acoustic Performance of the Outdoor Unit of a Split Air-Conditioner

DC-inverter split air-conditioner is widely used in Chinese homes as a result of its high-efficiency and energy-saving. Recently, the researches on its outdoor unit have focused on the influence of surrounding structures upon the aerodynamic and acoustic performance, however they are only limited to the influence of a few parameters on the performance, and practical design of the unit requires more detailed parametric analysis. Three-dimensional computational fluid dynamics（CFD） and computational aerodynamic acoustics（CAA） simulation based on FLUENT solver is used to study the influence of surrounding structures upon the aforementioned properties of the unit. The flow rate and sound pressure level are predicted for different rotating speed, and agree well with the experimental results. The parametric influence of three main surrounding structures（i.e. the heat sink, the bell-mouth type shroud and the outlet grille） upon the aerodynamic performance of the unit is analyzed thoroughly. The results demonstrate that the tip vortex plays a major role in the flow fields near the blade tip and has a great effect on the flow field of the unit. The inlet ring＇s size and throat＇s depth of the bell-mouth type shroud, and the through-flow area and configuration of upwind and downwind sections of the outlet grille are the most important factors that affect the aerodynamic performance of the unit. Furthermore, two improved schemes against the existing prototype of the unit are developed, which both can significantly increase the flow rate more than 6 %（i.e. 100 m3·h～（-1）） at given rotating speeds. The inevitable increase of flow noise level when flow rate is increased and the advantage of keeping a lower rotating speed are also discussed. The presented work could be a useful guideline in designing the aerodynamic and acoustic performance of the split air-conditioner in engineering practice.

Electrochemical Water Splitting:Bridging the Gaps Between Fundamental Research and Industrial Applications

Electrochemical water splitting represents one of the most promising technologies to produce green hydrogen,which can help to realize the goal of achieving carbon neutrality.While substantial efforts on a laboratory scale have been made for understanding fundamental catalysis and developing high-performance electrocatalysts for the two half-reactions involved in water electrocatalysis,much less attention has been paid to doing relevant research on a larger scale.For example,few such researches have been done on an industrial scale.Herein,we review the very recent endeavors to bridge the gaps between fundamental research and industrial applications for water electrolysis.We begin by introducing the fundamentals of electrochemical water splitting and then present comparisons of testing protocol,figure of merit,catalyst of interest,and manufacturing cost for laboratory and industry-based water-electrolysis research.Special attention is paid to tracking the surface reconstruction process and identifying real catalytic species under different testing conditions,which highlight the significant distinctions of corresponding electrochemical reconstruction mechanisms.Advances in catalyst designs for industry-relevant water electrolysis are also summarized,which reveal the progress of moving the practical applications forward and accelerating synergies between material science and engineering.Perspectives and challenges of electrocatalyst design strategies are proposed finally to further bridge the gaps between lab-scale research and large-scale electrocatalysis applications.

Bayesian Variable Selection for Mixture Process Variable Design Experiment

This paper discussed Bayesian variable selection methods for models from split-plot mixture designs using samples from Metropolis-Hastings within the Gibbs sampling algorithm. Bayesian variable selection is easy to implement due to the improvement in computing via MCMC sampling. We described the Bayesian methodology by introducing the Bayesian framework, and explaining Markov Chain Monte Carlo (MCMC) sampling. The Metropolis-Hastings within Gibbs sampling was used to draw dependent samples from the full conditional distributions which were explained. In mixture experiments with process variables, the response depends not only on the proportions of the mixture components but also on the effects of the process variables. In many such mixture-process variable experiments, constraints such as time or cost prohibit the selection of treatments completely at random. In these situations, restrictions on the randomisation force the level combinations of one group of factors to be fixed and the combinations of the other group of factors are run. Then a new level of the first-factor group is set and combinations of the other factors are run. We discussed the computational algorithm for the Stochastic Search Variable Selection (SSVS) in linear mixed models. We extended the computational algorithm of SSVS to fit models from split-plot mixture design by introducing the algorithm of the Stochastic Search Variable Selection for Split-plot Design (SSVS-SPD). The motivation of this extension is that we have two different levels of the experimental units, one for the whole plots and the other for subplots in the split-plot mixture design.

对于中国传统服装“开裆裤”的调查与研究——应用Anonymous Design为卧床癌病患者设计的下装研究

本文是日本学术振兴会科学研究费基金项目中以“应用Anonymous Design来为卧床癌症患者设计的下装研究”阶段性成果。在这项研究中,笔者于2019年2月对中国开裆裤进行了实物调研。开裆裤通常被认为是幼儿使用的、裆部有开口的裤子,其原型具有很悠久的历史,有不同的样式。关于Anonymous Design,没有统一的定义,笔者在这项研究中将其界定为“没有特定的作者或设计师设计过的物品。典型的例子如传统服装,它是前人的创造力与智慧的结果、产物、或行为。虽质朴但其易于使用的功能性得以长期被沿用,现代人认为“理所当然”的事物原点”。开裆裤完全符合笔者定义的Anonymous Design。本文主要论述笔者在中国进行的开裆裤调研成果,以及整理归纳开裆裤的结构和款式,并提出开裆裤的设计具有“卧床癌症患者使用的下装”所需的应用可能性。

Optimal Designs of Wound Field Switched Flux Machines with Different DC Windings Configurations

Wound field switched flux(WFSF)machines exhibits characteristics of the simple robust rotor,flexible flux-adjustable capability,and no risk of demagnetization.However,they suffer from a poor torque density compared with permanent magnet machines due to the saturation.Therefore,in this paper,two WFSF machines with single-and double-layer DC windings,respectively,are optimized for the maximum torque.The end-winding(EW)lengths differ in these two machines,which can affect the optimal design.Design parameters including the DC to armature winding copper loss ratio,slot area ratio and split ratio are optimized when two machines have the same copper loss and overall sizes.In addition,the influence of the flux density ratio,total copper loss,air-gap length and aspect ratio on the optimal split ratio is investigated using the finite element method and results are explained through the analytical model accounting for the saturation.It is discovered that the EWs have no effect on the optimal copper loss ratio,which is unity.In terms of the slot area ratio,the machine with single-layer DC windings prefers smaller DC slot areas than armature slot areas.In the WFSF machine with longer EWs,the optimal split ratio becomes smaller.Moreover,compared with other parameters,the flux density ratio can significantly affect the optimal split ratio.

东津黄河大桥主桥总体设计

东津黄河大桥主桥为(50+180+420+180+50) m双塔钢-混组合梁斜拉桥,采用半飘浮结构体系;主梁采用宽34 m的双边钢箱-混凝土桥面板组合梁;桥塔采用无下横梁的A形桥塔+分离式承台,承台间设横向系梁,塔梁交接处设置牛腿支承主梁,塔柱底部设置破冰体;基础采用?2.0 m钻孔灌注桩,最大桩长117 m;斜拉索采用标准抗拉强度1 860 MPa平行钢丝拉索,按空间双索面扇形布置,塔端采用钢锚梁+混凝土齿块锚固,梁端采用钢锚箱锚固于主梁边钢箱外腹板。计算结果表明,该桥结构静、动力性能良好,各项指标满足规范要求。

基于多种群协同优化的叠合板智能拆分设计

在装配式建筑中,叠合楼板的拆分主要是基于规则的半自动方式完成,其设计过程耗费大量时间和人力,难以获得最优解;同时,采用基于规则的方法存在构件规格多的问题,增加了构件加工的成本和时间。为了解决上述问题,本文提出基于多种群协同优化的叠合楼板智能拆分方法,以提高叠合楼板的标准化和模数化程度。将叠合板规格和数量、接缝宽度规格作为优化目标,每个叠合板位置和尺寸作为优化变量,考虑单构件的限重、限宽等加工和运输要求,建立多目标优化模型。采用变量关联性分析对叠合楼板所有布置区域进行分组划分,原高维优化问题转化为低维优化问题。通过上海某装配式建筑住宅项目的叠合楼板拆分实例应用,表明本文提出的叠合楼板智能拆分方法能够高效、快速地生成全部楼板的规格、数量和位置;相比基于规则的设计方法,本文提出的方法能够一定程度提高叠合板的标准化和模数化水平,且拆分结果满足设计规范和施工要求,从而验证了智能拆分方法的可行性和有效性,有利于装配式建筑的推广。

高阿丁枫人工中龄林生长对坡向和密度的响应

为了解高阿丁枫人工林的生长过程,2021年对林龄21 a的高阿丁枫人工林进行每木检尺,以胸径作为标准木选择的依据,西南坡不同密度中各选择1株,南坡不同密度中各选择3株高阿丁枫标准木作为解析木,分析不同坡向和造林密度组合的林木生长差异。结果表明:林龄21 a时,不同坡向和造林密度组合的高阿丁枫林木的平均胸径、树高和材积分别为17.60~20.78 cm、25.73~28.51 m和0.3186~0.4293 m3,林木尚处于旺盛的生长阶段;处理组合间以上生长量均呈现极显著的差异。林龄1~9、1~10、8~16 a期间分别是胸径、树高和材积的速生期,其连年生长量最高分别达2.19 cm/a、2.74 m/a和4.3966×10^(-2)m^(3)/a。坡向、密度及其交互作用显著或极显著地影响高阿丁枫林木的生长。高阿丁枫隶属热区长寿命大径材树种,速生期延续较长,其生长对立地和密度较为敏感。优质高效的高阿丁枫人工林培育应选择最适宜的立地和造林密度,并且适时开展密度的动态调控。综上所述,造林密度通过影响树高生长从而影响材积生长,南坡采用3 m×2 m×5 m非均匀密度造林的单株总材积最大。研究结果可应用于生产实践中高阿丁枫优质高效人工林培育的立地选择和密度控制。

近红外驱动光催化全分解水:进展与展望

实现高效、低成本的太阳能光催化全分解水制氢是解决当前环境污染和化石能源过度使用等问题的理想方案.然而,目前光催化分解水的转化效率(低于10%)普遍较低,这成为其实际应用的主要障碍.从太阳光谱的响应范围来看,现有的光催化剂大多局限于紫外光或可见光区域,而近红外光区的光催化剂开发仍然非常有限.尽管近红外光在太阳光谱中占比超过一半,蕴含着巨大的能源潜力,但遗憾的是,目前大部分光催化剂无法在该波段实现高效的光催化反应.根据理论预测,光分解水的转化效率有望随着催化剂响应太阳光波长范围的扩大而显著提高.因此,如何最大限度地利用太阳能,特别是近红外光区域的光能,开发高效的近红外光响应光催化全解水制氢催化剂,已成为当前能源、环境、化学工程领域研究的热点.本文综述了近红外光驱动全分解水光催化剂在材料设计和调控方面的最新进展,涉及窄带隙半导体、带隙工程、上转换效应、局域表面等离子体效应和光敏化作用等策略.首先,从热力学和动力学的角度分析了近红外光驱动全分解水的难点:对于大多数半导体而言,要实现近红外驱动全分解水不仅要求理论带隙窄于1.77 eV,而且必须超过水氧化还原分解电位(1.23 eV),同时由于存在电位损失和动力学过电位,实际的带隙结构应在1.6–2.4 eV,这对半导体的能带结构提出了较为苛刻的要求.此外,全分解水反应的可逆性、溶解氧的影响以及材料的光稳定性问题也是实现近红外光驱动全分解水的挑战.其次,总结了各方法制备的催化剂全分解水制氢的性能,分析了其近红外光子捕获方法的优缺点,特别指出了如何在每种方法的基础上进一步促进光生载流子的分离以及近红外光子的捕获能力(比如:负载贵金属单原子助催化剂、多种方法结合构筑多元复合体系以及光催化剂表面优化等).同时,强调了在近红外驱动全分解水过程中材料特征、催化性质与功能机理三者之间的关系.尤其是利用等离子体效应和光敏化作用来实现近红外光驱动全分解水的机理,目前尚不明确,需要结合理论计算以及先进的时空分辨仪器进一步研究电荷转移机制.另外,总结了全光谱响应的全分解水制氢光催化剂在材料设计和调控方面的最新进展,包括:光敏化作用的应用、带隙调控的策略、局域表面等离子体效应的研究,以及乌尔巴赫带尾吸收捕获技术的探索.最后,归纳并展望了未来近红外驱动全分解水光催化剂所面临的挑战与机遇.尽管近年来国内外学者们围绕着近红外驱动全分解水制氢光催化剂开展了系列研究工作,取得了一些突破性进展,但近红外驱动全分解水制氢效率仍然较低以及对于近红外响应光催化剂的设计和调控方面仍然面临着许多挑战.如何设计和开发廉价、稳定且高效的近红外驱动全分解水制氢光催化剂仍需进一步探索.因此,未来需要结合不同构筑方法的优势来加强近红外区的光捕获能力、实现多元复合材料界面间的精准调控、通过高端原位时空分辨仪器以及理论计算剖析近红外驱动全分解水的过程等方面对近红外响应光催化材料进行深入研究.

红花果球喂入分距机构的设计及运动学分析

针对红花采摘机器人末端执行器采摘时由于红花果球挤拢后分散间距小、互相遮挡而使定位不准确的问题,提出一种在红花植株喂入阶段同时对果球进行疏散分距的方法,设计了一种红花果球喂入分距机构,并对机构的主体结构与结构参数进行设计和机构运动学分析,结果表明:整个运动期间,机构运行速度和加速度无瞬时突变,运动平稳可靠,满足设计要求。搭建了红花果球喂入分距性能试验台,并进行试验,结果表明:采用喂入分距作业可减少红花果球的遮挡,分距合格率为92.33%,果球遮挡率为3.15%,植株和果球损伤的比例分别为0.64%和1.05%,该喂入分距机构有效增加了夹持挤拢操作后的相邻红花果球间距,使红花果球呈平面条带状规整排列,降低采摘难度。研究可为红花机械化采摘提供理论依据。

Minimum secondary aberration fractional factorial split-plot designs in terms of consulting designs

It is very powerful for constructing nearly saturated factorial designs to characterize fractional factorial (FF) designs through their consulting designs when the consulting designs are small. Mukerjee and Fang employed the projective geometry theory to find the secondary wordlength pattern of a regular symmetrical fractional factorial split-plot (FFSP) design in terms of its complementary subset, but not in a unified form. In this paper, based on the connection between factorial design theory and coding theory, we obtain some general and unified combinatorial identities that relate the secondary wordlength pattern of a regular symmetrical or mixed-level FFSP design to that of its consulting design. According to these identities, we further establish some general and unified rules for identifying minimum secondary aberration, symmetrical or mixed-level, FFSP designs through their consulting designs.