摘要：电化学二氧化碳还原反应(CO_(2)RR)通过将CO_(2)转化为高价值化学品和燃料来降低其在大气中的浓度,是解决能源危机的重要途径.因此,合理设计高效、经济的电化学催化剂至关重要.研究发现,铜(Cu)是一种性能优越的金属催化剂,可将CO_(2)还原成碳氢化合物和醇类,尤其是C_(2+)产物.然而,Cu催化剂也存在一定问题(如过电位高和CO_(2)RR选择性差等),从而限制了其应用.近年来,单原子催化剂(SACs)因其具有高活性、高选择性和高稳定性,已成为异相催化剂领域的新兴研究前沿.本文总结了CO_(2)RR的各种铜基SACs的最新研究进展,尤其是活性位点与关键反应中间产物相互作用的调控策略.这种相互作用对于设计活性位点以及优化多电子还原步骤和提高催化性能非常重要.同时,本文还讨论了金属中心调控、铜基单原子合金催化剂、非金属SACs、串联催化剂和复合催化剂等研究前沿.最后,总结了SACs应用于CO_(2)RR的挑战与展望.

摘要：Although the torso plays an important role in the movement coordination and versatile locomotion of mammals,the structural design and neuromechanical control of a bionic torso have not been fully *** this paper,a parallel mechanism is designed as a bionic torso to improve the agility,coordination,and diversity of robot *** mechanism consists of 6-degree of freedom actuated parallel joints and can perfectly simulate the bending and stretching of an animal’s torso during walking and *** overall spatial motion performance of the parallel mechanism is improved by optimizing the structural *** on this structure,the rhythmic motion of the parallel mechanism is obtained by supporting state *** neural control of the parallel mechanism is realized by constructing a neuromechanical network,which merges the rhythmic signals of the legs and generates the locomotion of the bionic parallel mechanism for different motion *** results show that the complete integrated system can be controlled in real time to achieve proper limb-torso *** coordination enables several different motions with effectiveness and good performance.

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：Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade sodium resources,while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode ***-organic framework(MOFs)derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition,nanostructure,chemical and physical ***,we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage *** MOF formation time increases,the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2,with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell *** SIBs anodes,bi-phase NiSex@C/CNT-10h(10 h of hydrothermal synthesis time)exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g,long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 *** simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium *** understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries,catalysis,sensors,and environmental remediation.

摘要：采用简便有效的方法,制备了生物兼容性强、放射性标记羟基磷灰石(HAp)纳米粒子的正电子发射计算机断层显像(PET)纳米探针。在合成HAp纳米粒子的过程中,放射性的^(18)F作为掺杂剂,占据HAp晶格中羟基位置,在短时间内牢固地标记到HAp上。^(18)F不仅标记在纳米粒子的表面,而且还通过强的化学键标记在纳米颗粒的内部。以达到提高标记量并防止辐射泄漏的目的。设计的高标记量的放射性纳米探针应用于动物实验并靶向到达脏器器官。

摘要：AIM： To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS： A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea. The microstructure of the acellular corneal matrix was observed by transmission electron microscopy （TEM） and hematoxylin and eosin （H＆E） staining. The mechanical properties were detected by a rheometer and a tension machine. The acellular corneal matrix was also transplanted into a rabbit cornea and cytokeratin 3 was used to check the immune phenotype, RESULTS： The microstructure and mechanical properties of the ostrich cornea were well preserved after the decellularization process, in vitro, the methyl thiazolyl tetrazoUum results revealed that extracts of the acellular ostrich corneas （AOCs） had no inhibitory effects on the proliferation of the corneal epithelial or endothelial cells or on the keratocytes, The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea （APC） transplantation, The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer, CONCLUSION： We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft.

摘要：Advanced electromagnetic(EM)wave absorbing materials with strong absorption and broad bandwidth are important for military stealth and elimination of microwave pollution in consumers’*** organic framework(MOF)-derived metal/carbon hybrids with ordered structure are significantly urgent in this *** this contribution,we presented a design strategy of hollow cage-like or solid box-like magnetic/dielectric Fe/Co/C and dielectric Fe/Mn/C EM wave absorbing nanomaterials via pyrolyzing Prussian blue’s analogs with controllable topology and phase *** solid box-like Fe/Co/C and hollow cage-like Fe/Mn/C showed favorable absorption property with a broad effective absorption bandwidth(EAB)and a low reflection loss(RL).Especially,the EAB of 8.8 GHz at a thickness of 2.5 mm for solid box-like Fe/Co/C nanocomplex prepared at 900℃is a new record for this type of *** design and tuning strategy for EM wave absorbers derived from topology-controllable MOF is important for EM functional materials possessing great potential in military stealth and consumers’electronics.

摘要：用分子束外延技术将高灵敏度的In As/Al Sb量子阱结构的Hall器件赝配生长在Ga As衬底上。设计了由双δ掺杂构成的Hall器件的新结构,有效地提高了器件的面电子浓度。与传统的没有掺杂的In As/Al Sb量子阱结构的Hall器件相比,室温下器件电子迁移率从15 000 cm^2·V^(-1)·s^(-1)提高到16 000 cm^2·V^(-1)·s^(-1)。AFM测试表明材料有好的表面形态和结晶质量。从77 K到300 K对Hall器件进行霍尔测试,结果显示器件不同温度范围有不同散射机构。双δ掺杂结构形成高灵敏度、高二维电子气(2DEG)浓度的In As/Al Sb异质结Hall器件具有广阔的应用前景。

摘要：Water oxidation is significant in both natural and artificial *** nature,water oxidation occurs at the oxygen‐evolving center of photosystem II,and leads to the generation of oxygen,protons,and *** last two are used for fixation of carbon dioxide to give *** artificial processes,the coupling of water oxidation to evolve O2and water reduction to evolve H2is known as water splitting,which is an attractive method for solar energy conversion and *** water oxidation is a thermodynamically uphill reaction and is kinetically slow,this reaction causes a bottleneck in large‐scale water *** a consequence,the development of new and efficient water oxidation catalysts(WOCs)has attracted extensive *** efforts have identified a variety of mononuclear earth‐abundant transition‐metal complexes as active and stable molecular *** review article summarizes recent progress in research on mononuclear catalysts that are based on first‐row transition‐metal elements,namely manganese,iron,cobalt,nickel,and *** attention is paid to catalytic mechanisms and the key O?O bond formation *** information is critical for designing new catalysts that are highly efficient and stable.

摘要：Ag nanoparticles (NPs) were deposited on the surface of g-C3N4 (CN) by an in situ calcination method. NiS was successfully loaded onto the composites by a hydrothermal method. The results showed that the 10 wt%-NiS/1.0 wt%-Ag/CN composite exhibits excellent photocatalytic H2 generation performance under solar-light irradiation. An H2 production rate of 9.728 mmol·g^-1·h^-1 was achieved, which is 10.82-, 3.45-, and 2.77-times higher than those of pure g-C3N4, 10 wt%-NiS/CN, and 1.0 wt%-Ag/CN composites, respectively. This enhanced photocatalytic H2 generation can be ascribed to the co-decoration of Ag and NiS on the surface of g-C3N4, which efficiently improves light harvesting capacity, photogenerated charge carrier separation, and photocatalytic H2 production kinetics. Thus, this study demonstrates an effective strategy for constructing excellent g-C3N4-related composite photocatalysts for H2 production by using different co-catalysts.