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：Tissue-engineered cartilage(TEC)remains a potential alternative for the repair of articular cartilage ***,there has been a significant different between the properties of TEC and those of natural *** have shown that mechanical stimulation such as compressive load can help regulate matrix remodelling in TEC,thus affecting its biomechanical ***,the influences of shear induced from the tissue fluid phase have not been well studied and may play an important role in tissue regeneration especially when integrated with the compressive ***,the aim of this study was to quantitatively investigate the effects of combined loading mechanisms on TEC in vitro.A bespoke biosimulator was built to incorporate the coupled motion of compression,friction and *** specimens,encapsulating freshly isolated rabbit chondrocytes in a hydrogel,were cultured within the biosimulator under various mechanical stimulations for 4 weeks,and the tissue activity,matrix contents and the mechanical properties were *** groups were categorized according to different mechanical stimulation combinations,including strain(5-20%at 5%intervals)and frequency(0.25 Hz,0.5 Hz,1 Hz),and the effects on tissue behaviour were *** the dynamic culture process,a combined load was applied to simulate the combined effects of compression,friction and shear on articular cartilage during human *** results indicated that a larger strain and higher frequency were more favourable for the specimen in terms of the cell proliferation and extracellular matrix ***,the combined mechanical stimulation was more beneficial to matrix remodelling than the single loading ***,the contribution of the combined mechanical stimulation to the engineered cartilaginous tissue matrix was not sufficient to impede biodegradation of the tissue with culture time.

摘要：Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint *** this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf *** ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3d-printed groove morphology,which is significantly impacted by the printing orientation of *** the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady *** transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,***,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications.

摘要：To achieve sufficient air conditioning of large buildings,reasonable air distribution in indoor spaces is an effective method for creating stratified air ***,optimizing the air distribution in large buildings is extremely *** this paper,we expound on a new method for air distribution design and optimization based on target value evaluation and summarize the relevant design processes based on an orthogonal test and by decoupling the effects of the size of the tuyere,airflow temperature,air-supply angle and velocity on air ***,we present a design *** optimize the distribution of a lateral air supply in winter,the deflection angle,velocity and temperature of the air supply can be determined in *** the large and tall building types addressed in this paper,the optimal air-supply angle is 2°,the optimal air-supply velocity is 8 m/s,and the optimal air-supply temperature is 19℃.

摘要：Heart diseases remain the top threat to human health,and the treatment of heart diseases changes with each passing *** evidence shows that three-dimensional(3d)printing allows for a more precise understanding of the complex anatomy associated with various heart *** addition,3d-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical *** introduce examples of the clinical applications of different types of 3d printing based on specific cases and clinical application scenarios of 3d printing in treating heart *** also discuss the limitations and clinically unmet needs of 3d printing in this context.

摘要：Electrocatalysis is a promising approach to clean energy conversion due to its high efficiency and low environmental pollution. Noble metal materials have been studied to show high activity toward electrocatalyltic reactions, although such applications remain restricted by the high cost and poor durability of the noble metals. By precisely adjusting the catalyst composition, size, and structure, electrocatalysts with excellent performance can be obtained. Atomic layer deposition(ALd) is a technique used to produce ultrathin films and ultrafine nanoparticles at the atomic level. It possesses unique advantages for the controllable design and synthesis of electrocatalysts. Furthermore, the homogenous composition and structure of the electrocatalysts prepared by ALd favor the exploration of structure-reactivity relationships and catalytic mechanisms. In this review, the mechanism, characteristics, and advantages of ALd in fabricating nanostructures are introduced first. Subsequently, the problems associated with existing electrocatalysts and a series of recently developed ALd strategies to enhance the activity and durability of electrocatalysts are presented. For example, the deposition of ultrafine Pt nanoparticles to increase the utilization and activity of Pt, fabrication of core–shell, overcoat, nanotrap, and other novel structures to protect the noble-metal nanoparticles and enhance the catalyst stability. In addition, ALd developments in synthesizing non-noble metallic electrocatalysts are summarized and discussed. Finally, based on the current studies, an outlook for the ALd application in the design and synthesis of electrocatalysts is presented.

摘要：为提高稠油井电加热系统的加热效率,解决油田中频电源加热运行控制主要依靠人工经验设置和低效的自动控制造成电能浪费的现状,本文设计了稠油电加热嵌入式控制装置。基于非嵌入式获取的油井生产电信号,以稠油开采电机的电功率为闭环反馈信号,获取油液最优温度的参考输入。在此基础之上,通过井口油液温度的微分反馈环节,改善温度迟滞效应,实现中频电源的节能优化控制。通过对嵌入式硬件核心电路模块的设计和主要软件功能的开发,不仅实现了稠油井电加热过程的动态控制,还实现了各项运行指标的现场及云端的实时监测。稠油井场试验分析表明,所设计的稠油电加热嵌入式控制装置符合井场节能安全的生产需求,节约能耗可达20%。

摘要：理解铁电材料畴结构在低温条件下的翻转行为,对于铁电物理以及其在宽温域的应用都非常重要;然而,目前在低温条件下直接观测介观尺度下的畴翻转仍然面临着巨大的挑战.本论文利用铁酸铋(BiFeO_(3))作为模型来研究3.6–260 K温度范围内的铁电畴翻转行为.菱形相的BiFeO_(3)在温度为130 K时观测到了明显的铁电保持失效现象;这是因为BiFeO_(3)在130 K附近有较大的热释电系数,从而使其升温到该温度附近时释放了大量的热释电电荷,进而产生较强的退极化场,导致铁电极化翻转.另外,本论文还发现通过纳米尺度设计相界可以有效地抑制铁电保持失效.本研究为变温条件下,尤其是低温温域,研究铁电翻转提供了实验范式.

摘要：Hydrogel-Ⅰ was fabricated via sodium alginate in situ-embedding with MAL powders and then applied to decontaminating Pb(Ⅱ) from water. Conditions for preparing Hydrogel-Ⅰ and the adsorption of Pb(Ⅱ) over Hydrogel-I were optimized through response surface methodology coupled with central composite design. XPS revealed that the groups of —OH, —COO—, —NH, —NHand —CSS— carried by Hydrogel-Ⅰ were responsible for the uptake of Pb(Ⅱ). Ions exchange, surface complexation, electrostatic attraction and pore-filling effect contributed to the adsorption process. Adsorption performances of Pb(Ⅱ) by Hydrogel-Ⅰ and MAL powders were compared. Although they exhibited similar adsorption rate and maximum adsorption capacity(qm), the reusing ability of Hydrogel-Ⅰ was better and it was easier to be separated from aqueous solution after treatment. Even compared with organic hydrogel materials,Hydrogel-Ⅰ presented relatively quick adsorption speed and high adsorption capacity. It can be concluded that Hydrogel-Ⅰ could be an alternative scavenger for the treatment of Pb(Ⅱ) from aqueous solution.

摘要：Lithium carbon dioxide(Li-CO_(2))batteries deliver a theoretical energy density of 1876 W h kg^(-1) in terms of effective utilization of greenhouse *** battery system is considered to be an encouraging electrochemical energy storage device and a promising alternative to Li-ion ***,the main drawback of Li-CO_(2) batteries is their accumulative discharge product of Li_(2)CO_(3)/C,which leads to large overpotential and poor cycling ***,specific and efficient catalysts must be explored to enhance the decomposition of Li_(2)CO_(3)/***-atom catalysts(SACs)are regarded as promising heterogeneous catalysts owing to their maximized utilization of metal atoms and strong interfacial electronic ***,single-metal atoms of Fe,Co,and Ni uniformly anchored on N-doped reduced graphene oxide(rGO),designated as Fe_(1)/N-rGO,Co1/N-rGO,and Ni_(1)/N-r GO,respectively,are designed and fabricated to investigate their catalytic activity toward the decomposition of Li_(2)CO_(3)/*** them,Fe_(1)/N-rGO delivers a high discharge capacity of 16,835 mA h g^(-1) at 100 mA g^(-1) and maintains stability for more than 170 cycles with a discharge voltage of 2.30 V at 400 mA g^(-1).Therefore,this catalysts are overwhelmingly superior to other *** work reveals the advances of SACs in Li-CO_(2) batteries and offers an effective method for realizing high-performance Li-CO_(2) batteries.