摘要：A series CeO2（ZrO2）/TiO2 catalysts were modified with Er using a sol-gel *** catalytic activity of the obtained catalysts in the selective catalytic reduction（SCR） of NO with NH3 was investigated to determine the appropriate Er *** catalysts were characterized using X-ray diffraction,N2 adsorption,NH3 temperature-programmed desorption,H2 temperature-programmed reduction,photoluminescence spectroscopy,electron paramagnetic resonance spectroscopy,and X-ray photoelectron *** results showed that the optimum Er/Ce molar ratio was 0.10;this catalyst had excellent resistance to catalyst poisoning caused by vapor and sulfur and gave more than 90% NO conversion at 220–395 ℃ and a gas hourly space velocity of 71 400 h^-*** incorporation increased the Ti^3＋ concentrations,oxygen storage capacities,and oxygen vacancy concentrations of the catalysts,resulting in excellent catalytic *** incorporation also decreased the acid strength and inhibited growth of TiO2 and CeO2 crystal particles,which increased the catalytic *** results show that high oxygen vacancy concentrations and oxygen storage capacities,large amounts of Ti^3＋,and low acid strengths give excellent SCR activity.

摘要：C1 chemistry is the essence of coal chemistry and natural gas chemistry. Catalytic methods to efficiently convert C1 molecules into fuels and chemicals have been extensively studied. Syngas（CO ＋H_2） conversion is the most important industrial reaction system in C1 chemistry, and Fe and Co catalysts, two major industrial catalysts, have been the focus of fundamental research and industrial application. In the last decade, considerable research efforts have been devoted to discoveries concerning catalyst structure and increasing market demands for olefins and oxygenates. Since the development of efficient catalysts would strongly benefit from catalyst design and the establishment of a new reaction system, this review comprehensively overviews syngas conversion in three main reactions, highlights the advances recently made and the challenges that remain open, and will stimulate future research activities. The first part of the review summarizes the breakthroughs in Fischer-Tropsch synthesis regarding the optimization of activity and stability, determination of the active phase, and mechanistic studies. The second part overviews the modulation of catalytic structure and product selectivity for Fischer-Tropsch to olefins（FTO）. Catalysts designed to produce higher alcohols, as well as to tune product selectivity in C1 chemistry, are described in the third section. Finally, present challenges in syngas conversion are proposed, and the solutions and prospects are discussed from the viewpoint of fundamental research and practical application. This review summarizes the latest advances in the design, preparation, and application of Fe/Co-based catalysts toward syngas conversion and presents the challenges and future directions in producing value-added fuels.

摘要：基于二维过渡金属硫化物的全包覆晶体管是后硅时代的理想电子器件,从玻尔兹曼输运理论出发,在考虑载流子的主要外秉散射机制后,针对三种典型的栅介质(Al_(2)O_(3),HfO_(2)和BN)构筑的单层MoS_(2)晶体管的电学性能进行了系统的理论研究。为解决介质中表面光学声子散射被高估这一常见问题,使计算更为准确,在电介质和沟道间的建模中引入了“死区”概念。重点针对微电子1nm及以下技术节点用途晶体管的电荷迁移率和电流密度等指标进行了探讨.研究表明,在沟道长度小于10nm的情况下,晶体管开态电流均可超2mAμm。上述结果阐明了基于单层半导体构筑晶体管在终极微缩条件下的性能潜力,对深度摩尔器件设计具有一定的参考价值。

摘要：The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125,0.25,0.375,y=0.625)]alloys were systematically studied by the first-principles *** the formation energy,the martensite is smaller than the austenite,the Ni–(Co)–Mn–Cu–Ti alloys studied in this work can undergo martensitic *** austenite and non-modulated (NM) martensite always present antiferromagnetic state in the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) (y<0.625) *** y=0.625 in the Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) series,the austenite presents ferromagnetic state while the NM martensite shows antiferromagnetic *** doping can decrease the thermal hysteresis and anisotropy of the Ni–(Co)–Mn–Ti *** Mn and decreasing Ti content can improve the shear resistance and normal stress resistance,but reduce the toughness in the Ni–Mn–Cu–Ti *** the ductility of the Co–Cu co-doping alloy is inferior to that of the Ni–Mn–Cu–Ti and Ni–Co–Mn–Ti *** electronic density of states was studied to reveal the essence of the mechanical and magnetic properties.

摘要：实现材料的顺电-铁电相变可以丰富铁电材料的多样性.本文通过设计和引入A位非化学计量缺陷,在Ba_(0.9)(Fe_(0.5)Nb_(0.5))O_(3-δ)薄膜中实现了晶格畸变,诱导出室温铁电.薄膜中引入的四方畸变和局部位错促进了结构的对称性破缺以及自发极化的出现.在这里我们成功实现了室温下剩余极化Pr约为8μC cm^(-2)的铁电性和高达450℃的相稳定性温度我们的研究工作为通过缺陷工程发现和调节新型铁电材料提供了一种实用的方法.

摘要：Chemically modified carbonaceous materials have attained utmost attention in the fields of renewable energy storage and conversion,due to the controllable physicochemical properties,tailorable micro-/nanostructures,and respectable ***,P-doped mesoporous carbons were synthesized by using F127 as the soft template,organophosphonic acid as the P source and phenolic resin as the carbon *** amounts of iron species were introduced to act as a graphitization *** synthesized carbons exhibit the well-defined wormhole-like pore structure featuring high specific surface area and homogenously doped P ***,introducing iron species during the synthesis process can optimize the textural properties and the degree of graphitization of carbon *** doping amount of P has an important effect on the porous structure and the defect degree,which correspondingly influence the active sites and the oxygen reduction reaction(ORR)*** resultant material presents superior catalytic activity for the ORR,together with remarkably enhanced durability and methanol tolerance in comparison with the commercial Platinum catalyst,demonstrating the possibility for its use in electrode materials and electronic nanodevices for metal-air batteries and fuel cells.

摘要：The ability to detect conspecific＇s distress is crucial for animal survival. In rodent models, observational fear （OF） occurs when one animal perceives another fear related negative emotions, which may model certain behaviors caused by witnessing traumatic experiences in humans. Anterior cingulate cortex （ACC） has been showed to play a crucial role in OF. However, cellular and neural circuit basis relating to ACC governing OF is poorly understood. Here, we used Designer Receptor Exclusively Activated by a Designer Drug （DREADD） system to investigate the cell type specific circuit mechanism of ACC in OF. Firstly, inhibitory hM4D （Gi） designer receptor together with clozapine N-oxide （CNO） injection was applied to inactivate ACC neurons in the observer mice. We found that, chemogenetic inhibition of ACC resulted in a decreased freezing response in the observer mice. Next, combining PV-ires-Cre mice and Cre-dependent DREADD system, we selectively targeted the ACC parvalbumin （PV） interneurons with the excitatory hM3D （Gq） designer receptor. Activation of ACC PV interneurons following CNO injection reduced freezing response in the observer mice, while had no effect on freezing response in the demon- strator mice. Finally, monosynaptic rabies retrograde tracing revealed that ACC PV interneurons receive inputs from the mediodorsal thalamic nucleus （MD） and the ventromedial thalamic nucleus （VM）, both known for their roles in OF. Taken together, these findings reveal that ACC activation is important for OF, during which PV interneurons in ACC play an important regulatory role. Abnormal function of ACC PV interneurons might contribute to the pathology of empathy- deficits related diseases, such as autism and schizoohrenia.

摘要：水凝胶作为承载组织的替代产品引起了广泛关注.然而,与能够通过有限的变形来承受复杂载荷的承载组织不同,传统的水凝胶由于其柔软的特性,无法在低应变状态下表现出刚性响应.基于承载组织的软硬组分之间的协同作用,我们设计了采用软基质(正泊松比)和硬框架(负泊松比)的复合水凝胶,其刚度分别比基质和框架高18.9和4.2倍.相反,结合软基质(正泊松比)和框架(正泊松比)的设计对刚度增强有限.通过有限元分析,揭示了软基质与框架之间正、负泊松比斥力作用的内在机理.本研究为今后设计基于软硬组分协同效应的复合水凝胶提供了思路.

摘要：Laser powder bed fusion(LPBF)makes it possible for biodegradable zinc(Zn)to be used to produce customized orthopedic *** this research,we investigate the impact of laser power and scanning speed on the development of surface quality,relative densification,and texture during LPBF of Zn *** laser power was able to decrease melt viscosity and surface tension,which improved the metallurgical bonding between adjacent *** and twisted tracks also became continuous and *** speed could controlmolten-pool temperature to restrain grain natural orientation,achieving various crystal orientations and a weakened ***,it further avoided the thermal expansion and contraction caused by excessive energy storage and accumulation in the matrix,thus reducing the generation of high-dislocation *** a result,by selecting a reasonable laser power and scanning speed,the LPBF parts exhibited a flat surface morphology and a high density over 99.5%.Their average hardness,mechanical strength,and elongation reached 50.2 HV,127.8 MPa,and 7.6%,***,the parts displayed a moderate degradation rate and excellent osteogenic *** these results provide a basis for selecting process parameters to optimize the comprehensive properties of LPBF-processed Zn parts for biodegradable applications.

摘要：This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties,environmental disturbances and input ***,a virtual guidance control strategy is established on the basis of tracking error kinematics,which resolves the overall control system into two cascade ***,a first-order sliding mode differentiator is introduced in the derivation to avoid tedious analytic calculation,and a Gaussian error function-based continuous differentiable symmetric saturation model is explored to tackle the issue of input *** with backstepping design techniques,the neural network control method and an adaptive control approach are used to estimate composite items of the unknown uncertainty and approximation ***,Lyapunov-based stability analysis guarantees that control error signals of the closed-loop system are uniformly ultimately ***,simulation studies are conducted for the trajectory tracking of a moving target and a spiral line to validate the effectiveness of the proposed controller.