摘要：Homogeneous redox mediation is efficient in alleviating the shuttling effect and slow redox kinetics of lithium polysulfides in lithium-sulfur ***,their perfect performance is not fulfilled owning to the fact that the multi-step transformation of lithium polysulfides requests the multifunctional active positions for the tandem *** on the redox comediation principles,a promoter of mixing organodiselenide and organoditelluride(mixed-Se/Te)was raised to induce tandem catalysis and boost the effective electrochemical conversion of lithium *** specifically,diphenyl diselenide facilitated the liquid-liquid and solid-liquid transformation between lithium polysulfides and sulfur,while diphenyl ditelluride improved the solid-liquid transformation concerning lithium sulfide ***,even under high sulfur loading of 6.5 mg cm^(−2) and low electrolyte/sulfur ratio of 5.88μL mg^(−1),the 10 mM low concentration mixed-Se/Te promoter offered a high discharge capacity of 6.6 mAh cm^(−2) and high rate performance of 4.1 mAh cm^(−2) at 0.5 ***,the assembled 1.5 Ah-level lithium-sulfur pouch cells provide an energy density of 332 Wh kg^(−1) at 0.05 C and good cycling *** research demonstrates the applicability of propelling continuous sulfur conversion reactions with detached active positions and is anticipated to stimulate deep molecular design of kinetic promoter to targeted energy-associated redox reactions.

摘要：Covalent organic frameworks(COFs)are garnering significant interest in photocatalytic CO_(2) ***,their limited efficiency in separating photogenerated carriers and the scarcity of catalytic sites lead to suboptimal photocatalytic *** we develop a molecular engineering approach to design a pyrene-based COF(PyTa-H COF)confined cobalt single atoms photocatalyst(Co SACs)for CO_(2) *** moiety is introduced to enhance visible-light harvesting capability and improve charge separation in the ***,Co SACs enhance the photocatalytic activity by accelerating the migration of photo-induced carriers and reducing the reaction energy of the rate-determining ***,PyTa-H@Co achieves a CO production rate of 18.36 mmol g^(−1) h^(−1) and a selectivity of 94%in 4 h under visible light irradiation,which is comparable to the reported best-performing *** functional theory calculations reveal that the Co SACs greatly stabilize*COOH and significantly reduce the energy of the decisive step,leading to outstanding photocatalytic *** work,through molecular engineering design,highlights the critical relationship between catalyst structure and function in enhancing photocatalytic efficiency.

摘要：Inorganic-organic composite electrolyte is proved an effective way to enhance the overall performance of the ***,simply combining powder fillers with polymers is not sufficient for the application of composite *** this work,we designed an ultrathin organic-inorganic composite solid electrolyte with high mechanical strength and ionic conductivity,in which the inorganic Li1.5Al0.5Ge1.5(PO_(4))3(LAGP)solid electrolyte is prefiberized into a three-dimensional nanofiber network to serve as a self-supporting skeleton for the polyethylene oxide(PEO)*** continuous skeleton structure not only significantly improves the mechanical strength of the PEO-based electrolyte,but also forms a continuous lithium-ion conduction path,promoting the rapid migration of lithium *** fiber-reinforced composite electrolyte has an ionic conductivity of 8.27×10^(−4) S cm^(-1) at 60°C and a tensile strength of up to 4.29 ***,it exhibits a reduced overpotential and stable long-term cycling performance over 1700 h when used in Li/Li symmetric *** LiFePO_(4)(LFP)|Li cell assembled with the fiber-reinforced composite electrolyte also delivers a specific capacity of about 142 mAh g^(−1) over 300 cycles at 0.5 C and maintains good cycling *** work provides a novel idea for designing the next generation of safe and reliable organic-inorganic composite solid-state electrolyte membranes.

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：The S2 flow path design method of the transonic compressor is used to design the one stage fan in order to replace the original designed blade cascade which has two-stage transonic fan *** the modification design,the camber line is parameterized by a quartic polynomial curve and the thickness distribution of the blade profile is controlled by the double-thrice ***,the inlet flow has been pre-compressed and the location and intensity of the shock wave at supersonic area have been controlled in order to let the new blade profiles have better aerodynamic *** computational results show that the new single stage fan rotor increases the efficiency by two percent at the design condition and the total pressure ratio is slightly higher than that of the original *** the same time,it also meets the mass flow rate and the geometrical size requirements for the modification design.

摘要：Sweat loss monitoring is important for understanding the body’s thermoregulation and hydration status,as well as for comprehensive sweat *** recent advances,developing a low-cost,scalable,and universal method for the fabrication of colorimetric microfluidics designed for sweat loss monitoring remains *** this study,we propose a novel laserengraved surface roughening strategy for various flexible *** process permits the construction of microchannels that show distinct structural reflectance changes before and after sweat *** leveraging these unique optical properties,we have developed a fully laser-engraved microfluidic device for the quantification of naked-eye sweat *** sweat loss sensor is capable of a volume resolution of 0.5µL and a total volume capacity of 11µL,and can be customized to meet different performance ***,we report the development of a crosstalk-free dual-mode sweat microfluidic system that integrates an Ag/AgCl chloride sensor and a matching wireless measurement flexible printed circuit *** integrated system enables the real-time monitoring of colorimetric sweat loss signals and potential ion concentration signals without ***,we demonstrate the potential practical use of this microfluidic sweat loss sensor and its integrated system for sports medicine via on-body studies.

摘要：Composite-metal joints with a metal insert are one kind of connecting *** this paper,tensile experimental tests were carried out to investigate tensile properties of a compositemetal joint with a novel metal insert *** element models of the joint were established,and strain distribution and tensile strength were *** numerical results are in good agreement with the experimental *** show that the joint failure is dominated by shear properties of the resin *** the resin layer thickness in a certain range will improve the tensile strength of the joint,while increasing the radius of the fillet on the ending side of the metal insert will decrease the joint *** the resin layer plasticity will improve the joint *** effect of the embedded depth of the metal insert can be ignored.

摘要：A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation *** main procedures of bionic structure design were introduced *** parameter relationship betweenhollow stem of plant and the minimum weight was deduced in *** order to improve SSE of pylons, the structural characteristicsof hollow stem were investigated and *** pylon was designed based on analogous biological *** finite element method based simulation, the displacements and stresses in the bionic pylon were comparedwith those of the conventional *** show that the SSE of bionic pylon is improved ***, dynamic andelectromagnetism tests were carried out on conventional and bionic *** weight, stress, displacement and Radar CrossSection (RCS) of both pylons were *** results illustrate that the SSE of bionic pylon is markedly improvedthat specific strength efficiency and specific stiffness efficiency of bionic pylon are increased by 52.9% and 43.6% *** RCS of bionic pylon is reduced significantly.

摘要：As a key component of electro-optical systems, a Two-axis Scan mirror AssemblY(TSAY) is usually used for Line-of-Sight(LOS) precision pointing, tracking, scanning, and stabilizing. Therefore, it is necessary for a TSAY to have a large angular range, high dynamic characteristics, and small mirror surface distortion. Furthermore, vibration from carriers of electro-optical systems, such as spacecraft and airplanes, is inevitable, so it is critical to guarantee the control accuracy of a TSAY under vibration. In this paper, a TSAY prototype is designed and developed. To increase the control bandwidth, structural topology optimization is applied to the TSAY’s elliptical mirror to reduce the moment of inertia, meanwhile keeping surface flatness. A flexible hinge is adopted to achieve a large angular range. To suppress the angular perturbation caused by the base linear vibration, an adaptive feedforward loop with base-integrated Micro-Electro-Mechanical System(MEMS) accelerators is constructed to enhance the TSAY’s feedback loop. Simulation and experimental results show that the TSAY prototype’s two-axis mechanical angular ranges are more than ±3.2°, the mirror surface flatness Root Mean Square(RMS) value is better than 0.04 k, and the closed-loop bandwidth is beyond 330 Hz. These are suitable for most applications. Besides, the angular perturbation caused by the base vibration can be suppressed more than 37.7% with the addition of the adaptive feedforward loop.

摘要：With the improvement of requirement,design and manufacture technology,aero-engines for the future are characterized by further reduction in fuel consumption,cost,but increment in propulsion efficiency,which leads to ultra-high bypass *** intermediate turbine duct(ITD),which connects the high pressure turbine(HPT) with the low pressure turbine(LPT),has a critical impact on the overall performances of such future ***,it becomes more and more urgent to master the design technique of aggressive,even super-aggressive *** the last years,a lot of research works about the flow mechanism in the diffuser ducts were carried *** achievements were reported,but further investigation should be *** the aid of numerical method,this paper focuses on the change of performance and flow field of ITD,as well as nearby turbines,brought by rising angle(RA).Eight ITDs with the same area ratio and length,but different RAs ranges from 8 degrees to 45 degrees,are *** to the investigation,flow field,especially outlet Ma of swirl blade is influenced by RA under potential effect,which is advisable for designers to modify HPT rotor blades after changing *** addition to that,low velocity area moves towards upstream until the first bend as RA increases,while pressure loss distribution at S2 stream surface shows that hub boundary layer is more sensitive to RA,and casing layer keeps almost *** the other hand,the overall total pressure loss could keep nearly equivalent among different RA cases,which implies the importance of optimization.