Design Principles and Mechanistic Understandings of Non-Noble-Metal Bifunctional Electrocatalysts for Zinc-Air Batteries

Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs.

Research on the Course of Principles of Concrete Structure Design

Nowadays,education and teaching have become a hot topic,and teaching in colleges and universities is facing a brand-new development direction.Principles of Concrete Structure Design,as one of the main courses,transmits professional knowledge for students,enhances the students’professional ability,and further carries out in-depth research on the course to bring a better teaching effect for students.The article mainly focuses on the research of the principles of concrete structure design course,conducts an analysis of the teaching characteristics of the principles of concrete structure design course,and reasonably sets the teaching content from the optimization of the course teaching objectives;innovative course teaching methods can deepen the effect of knowledge understanding;reform of experimental practice teaching can lay down the effect of the internalization of knowledge,etc.The in-depth description and discussion of the relevant aspects of the research aim to provide guidelines for related research.

Single-atom electrocatalysts for lithium-sulfur chemistry:Design principle,mechanism,and outlook

Lithium-sulfur batteries(LSBs)have been regarded as one of the promising candidates for the next-generation“lithium-ion battery beyond”owing to their high energy density and due to the low cost of sulfur.However,the main obstacles encountered in the commercial implementation of LSBs are the notorious shuttle effect,retarded sulfur redox kinetics,and uncontrolled dendrite growth.Accordingly,single-atom catalysts(SACs),which have ultrahigh catalytic efficiency,tunable coordination configuration,and light weight,have shown huge potential in the field of LSBs to date.This review summarizes the recent research progress of SACs applied as multifunctional components in LSBs.The design principles and typical synthetic strategies of SACs toward effective Li–S chemistry as well as the working mechanism promoting sulfur conversion reactions,inhibiting the lithium polysulfide shuttle effect,and regulating Li+nucleation are comprehensively illustrated.Potential future directions in terms of research on SACs for the realization of commercially viable LSBs are also outlined.

Design Method for Road Reconstruction and Expansion

This article analyzes the method for designing routes in road reconstruction and expansion projects,using an actual engineering project as an example.This includes an overview of a specific road reconstruction and expansion project,an analysis of the preexisting road,the basic principles of the design road project,and an analysis of the design methods and steps.This study aims to offer some guidance for road reconstruction and expansion design.

Design Principles of the Non-smooth Surface of Bionic Plow Moldboard

The diverse non-smooth body surfaces to reduce soil adhesion are the evolutional results for the soil animals to fit the adhesive and wet environment and can be used as a biological basis for the design of bionic plow moldboard. The model surfaces for bionic simulation should be taken from soil animal digging organs, on which the soil motion is similar to what is on the surface of moldboard. By analyzing the distribution of non-smooth units on the body surface of the ground beetle jaw and the soil moving stresses, the design principles of the bionic moldboard for the local and the whole moldboard were presented respectively. As well, the effect of soil moving speed on reducing adhesion, the dimensions relationship between soil particles and non-smooth convexes, the relationship between the enveloping surface of non-smooth convexes and the initial smooth surface of the plow body, and the convex types of the sphere coronal and the pangolin scales,etc.were discussed.

Designing Advanced Aqueous Zinc-Ion Batteries:Principles,Strategies,and Perspectives

Aqueous zinc-ion batteries(AZIBs)are an appealing battery system due to their low cost,intrinsic safety,and environmental-friendliness,while their application is plagued by the obstacles from the cathode,electrolyte,and zinc anode.Summarizing the design principles and strategies toward the optimization of cathode,electrolyte,and zinc anode is crucial for the development of AZIBs.Herein,we present a comprehensive analysis of the design principles and promising strategies toward the improvement of AZIBs.Firstly,the various reaction mechanisms are summarized and the existing issues associated with the cathode,electrolyte,and zinc anode are discussed to guide the rational design of AZIBs.Subsequently,we provide an in-depth and comprehensive discussion on the design principles and strategies for the electrodes/electrolyte/separator optimization,and analyze the advantages and disadvantages of various strategies.Importantly,the design principles and strategies of the newly appeared conversion-type AZIBs,such as Zn-S battery and Zn-Se battery,are also discussed and analyzed.The effect of design strategies on the electrochemical performance and the relationship between the current issues and strategies are also unveiled in detail.Finally,some research trends and perspectives are provided for designing better AZIBs.

New design principles for the bath towards chromate-and crack-free conversion coatings on magnesium alloys

Cracking and low thickness are major obstacles to the high corrosion performance of conversion coating on magnesium alloy.In this work,the ratio of total acidity to p H(TA/p H)was applied as an indicator,and new principles regarding the design of conversion bath were proposed.The treatment bath should be composed of species that can be categorized into two groups:the first group of species that react with Mg substrate to increase the local p H at the interface;the second group that precipitate and contributes to the growth of coating.The species belong to second group exists in a supersaturated state and its precipitation process is almost independent on the reactions of the species in first group.By this way,a thick and crack-free two-layered conversion coating is obtained.Moreover,the nature of the adjustment of TA/p H and the roles of the oxidizing agent and catalyst were discussed.

Design Principles-Based Interactive Learning Tool for Solving Nonlinear Equations

Interactive learning tools can facilitate the learning process and increase student engagement,especially tools such as computer programs that are designed for human-computer interaction.Thus,this paper aims to help students learn five different methods for solving nonlinear equations using an interactive learning tool designed with common principles such as feedback,visibility,affordance,consistency,and constraints.It also compares these methods by the number of iterations and time required to display the result.This study helps students learn these methods using interactive learning tools instead of relying on traditional teaching methods.The tool is implemented using the MATLAB app and is evaluated through usability testing with two groups of users that are categorized by their level of experience with root-finding.Users with no knowledge in root-finding confirmed that they understood the root-finding concept when interacting with the designed tool.The positive results of the user evaluation showed that the tool can be recommended to other users.

Research on Enterprise Strategic Information System on Design Principle and System Composition

This paper intends to describe how to design an optimized and effective strategic information system （SIS） by using the existing resources under the new market circumstances in China. Some feasible methods are thus proposed, which are about the design of SIS by detailed analysis of the principle requirements. The paper also puts forward the architecture and configuration of SIS in China in general.

Design and Evaluation of a Differential Accelerometer for Drop-Tower Equivalence Principle Test with Rotating Masses

A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth＇s gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle （NEP）. We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.

On Design Principles of Micro-lectures of theme-based English Vocabulary for High-grade Primary School Students——A Case Study of a Class of Fifth-grade students in ECNU Affiliated Primary School

For English education primary school,English vocabulary teaching should be attach importance to because in the traditional class of English vocabulary teaching,teachers just fill young minds with knowledge points of each word in a 35-minute class yet fail to lay emphasis of learners’meaningful learning and autonomic learning as well as their very limited attention spans.To support traditional English vocabulary teaching classes,the research proposes the theme-based English vocabulary micro-lectures designed on the basis of experiential learning theory and constructivist learning theory as well as the analyses of target users of high-level students in the primary school.After application of the micro-lectures into practice,the research assesses the effect of the micro-lectures on the learners and then makes suggestions for design principles of theme-based vocabulary micro-lectures about selection of contents and vocabulary themes,supplementary teaching activities and teacher interaction in the micro-lectures for high-level students in the primary school.Also,the designers should make multi-level English vocabulary micro-lectures according to learners’English proficiency and increase repetition rates of vocabularies in the micro-lectures.

An Approach to Representation for Principle Scheme Design

One of the open issues in principle scheme design of mechanical systems is principle representation, which not only outlines the physical principles, but also facilitates the design synthesis. An energy-based approach to represent principle scheme design is proposed. Firstly, an energy interaction model of mechanical systems is established and an intermediate model is derived, in which principle scheme design is transformed into solving the energy functions of system. Then the energy functions are modeled with the language of bond graphs, and principle representation for components is presented. Finally, characteristics of the developed representation approach are analyzed and a design example of gate drive system is given to demonstrate this approach.

ECOLOGICAL DESIGN PRINCIPLES AND THEIR IMPLICATIONS ON WATER INFRASTRUCTURE ENGINEERING

Today’s water infrastructures are the outcome of an industrial revolution-based design that are now at odds with the current sustainability paradigm.The goal of this study was to develop a vision for engineering sustainable water infrastructures.A list of 99 ecological design principles was compiled from eleven authors and grouped into three themes:(1)human dimension,(2)learning from nature(biomimicry),and(3)integrating nature.The biomimicry concept was further divided into six sub-themes;(1)complex system properties,(2)energy source,(3)scale,(4)mass and energy flows,(5)structure,and function,and(6)diversity and cooperation.The implications of these concepts on water infrastructure design suggested that water infrastructure should be conceptualized in a more holistic way by not only considering water supply,treatment,and storm water management services,but also integrating into the design problem other provisioning,regulating,cultural,and supporting ecosystem services.A decentralized approach for this integration and innovation in adaptive design are necessary to develop resilient and energy efficient water infrastructures.

Laser-Induced Graphene:En Route to Smart Sensing

The discovery of laser-induced graphene(LIG) from polymers in 2014 has aroused much attention in recent years.A broad range of applications,including batteries,catalysis,sterilization,and separation,have been explored.The advantages of LIG technology over conventional graphene synthesis methods are conspicuous,which include designable patterning,environmental friendliness,tunable compositions,and controllable morphologies.In addition,LIG possesses high porosity,great flexibility,and mechanical robustness,and excellent electric and thermal conductivity.The patternable and printable manufacturing process and the advantageous properties of LIG illuminate a new pathway for developing miniaturized graphene devices.Its use in sensing applications has grown swiftly from a single detection component to an integrated smart detection system.In this minireview,we start with the introduction of synthetic efforts related to the fabrication of LIG sensors.Then,we highlight the achievement of LIG sensors for the detection of a diversity of stimuli with a focus on the design principle and working mechanism.Future development of the techniques toward in situ and smart detection of multiple stimuli in widespread applications will be discussed.

Design and applications of hollow‐structured nanomaterials for photocatalytic H2 evolution and CO2 reduction

Photocatalysis is considered a prospective way to alleviate the energy crisis and environmental pollution.It is therefore extremely important to design highly efficient photocatalysts for catalytic systems.In recent years,hollow‐structured materials have attracted considerable interest for application in energy conversion fields owing to their large specific surface areas,improved light absorption,and shortened charge carrier transfer path.Because they contain inner and outer surfaces,hollow‐structured materials can provide a superior platform for the deposition of other components.A number of hollow‐structured hierarchical systems have been designed and fabricated in recent decades.It is important to rationally design and construct complex hierarchical structures.In this review,general preparation approaches for hollow‐structured materials are presented,followed by a summary of the recent synthesis methods and mechanisms of typical hollow‐structured materials for applications in the photocatalytic field.Complex hollow‐structured hierarchical photocatalysts are classified into two types,hollow cocatalyst‐based and hollow host photocatalyst‐based,and the design principle and analysis of the photocatalytic reaction mechanism for photocatalytic H2 evolution and CO_(2) reduction are also introduced.The effects of hollow‐structured materials have also been investigated.This review provides a reference for the rational construction of advanced,highly efficient photocatalytic materials.

Rational design of bismuth-based catalysts for electrochemical CO_(2) reduction

Sustainable conversion of carbon dioxide(CO_(2))to high value-added chemicals and fuels is a promising solution to solve the problem of excessive CO_(2) emissions and alleviate the shortage of fossil fuels,maintaining the balance of the carbon cycle in nature.The development of catalytic system is of great significance to improve the efficiency and selectivity for electrochemical CO_(2) conversion.In particular,bismuth(Bi)based catalysts are the most promising candidates,while confronting challenges.This review aims to elucidate the fundamental issues of efficient and stable Bi-based catalysts,constructing a bridge between the category,synthesis approach and electrochemical performance.In this review,the categories of Bi-based catalysts are firstly introduced,such as metals,alloys,single atoms,compounds and composites.Followed by the statement of the reliable and versatile synthetic approaches,the representative optimization strategies,such as morphology manipulation,defect engineering,component and heterostructure regulation,have been highlighted in the discussion,paving in-depth insight upon the design principles,reaction activity,selectivity and stability.Afterward,in situ characterization techniques will be discussed to illustrate the mechanisms of electrochemical CO_(2) conversion.In the end,the challenges and perspectives are also provided,promoting a systematic understanding in terms of the bottleneck and opportunities in the field of electrochemical CO_(2) conversion.

Design and characteristics of a new type laminar plasma torch for materials processing

Laminar plasma jet(LPJ)generated by laminar plasma torch(LPT)has a favorable temperature and velocity distribution.Thus,it is superior to the turbulent plasma jet in material processing.However,most of the reported LPTs usually operate at a relatively low output power with a relatively low arc voltage and thermal efficiency,which limits its capabilities.In this context,this paper attempts to design a new type of high-power LPT with a relatively low arc current and a high thermal efficiency.In the first section,the design principle of the main components is studied and discussed in detail,and a new high-power LPT is proposed.Then,the experimental characteristics of the proposed high-power LPT are examined.Experimental results reveal the following characteristics of the proposed LPT.(1)The max jet length of the proposed LPT reaches at 540 mm.(2)Its mean arc voltage is higher than 290 V when the LPT works with arc currents lower than 200 A.leading to an output power greater than 50 kW.(3)The mean thermal efficiency is higher than 509f.Lastly,the proposed LPT has been applied to spheroidize the aluminum oxide powers.The experiment results for the production of spherical powders show that the proposed LPT hits a good characteristic for material processing.

Types of Ecological Revetments in Hydraulic Engineering

Compared with traditional bank protection, ecological revetments, as a new type of bank protection, can ensure the sustainable and healthy development of river ecology and has broad application prospects. In this paper, the design principles for ecological revetments and the factors that need to be considered in the selection of revetment plants were summarized; and the types of ecological revetments commonly used in water conservancy projects were summarized and classified according to the proportion of natural materials in revetment materials through domestic and foreign research and engineering examples, and their applicable scope and relevant merits were introduced. In conclusion, ecological revetments should get rid of its own limitations in the practical application process, and the river regulation scheme and revetment type should be selected comprehensively and flexibly combined with the status quo.

Design concept for the solid waste landfill site:a case study of Chuzhou City,China

This paper introduces landfill site of Chuzhou domestic waste, to which the improved anaerobic hygienic burying technology is applied. Chuzhou City, situated between Yangtze River and Huai River, is a window city in the east of Anhui Province. A landfill site with a capacity of 400 ton per day is to be constructed according to the city development plan and the garbage amount, This paper summarizes the landfill location, landform, groundwater, surface water, landfill stratal configuration, dominant wind, and the major machinery equipment. The projects of anti-percolation, seepage collection, seepage disposal, rainwater discharge, biogas diversion are deeply studied. The advanced design principle of the landfills is summarized, which is environment-friendly, science-oriented and economy-based. Environment-friendly principle is implemented in the selection of landfill location, construction of all projects, sealing up project and perfecting environment monitoring system; science-oriented principle prescribes that the design, construction, and management should be science-oriented; the selection of landfill location, design, plan optimization, resource-saving measures and comprehensive utilization should be economy-based Chuzhou domestic waste landfill site is qualified as a goiden model in this paper.