摘要：Due to their tunable acidity,shape selectivity,and excellent stability,zeolites are of great importance as solid acid materials in industrial *** the properties of the acid sites in zeolites allows for the rational design and fabrication of catalysts for target *** ether(DME)carbonylation,a critical chain-growth reaction for C1 resource utilization,is selectively catalyzed by the Brønsted acid sites within the eight-membered rings(8-MRs)of mordenite(MOR).It is anticipated that strengthening the Brønsted acidity—particularly in 8-MRs—will improve the catalytic performance of *** this work,density functional theory(DFT)calculations are first employed and the results used to design a modified MOR with stannum(Sn)and to predict the corresponding changes in *** by the theoretical studies,a series of Sn-modified MOR are synthesized via a defect-engineering and subsequent heteroatom-substitution *** partial desilication,isolated tetrahedral Sn species in an open configuration are successfully synthesized for the first time,within which tetrahedrally coordinated Al sites are *** acidic characterization is used to confirm that the acidity of the Brønsted acid sites is enhanced by the introduction of the Sn species;as a result,the sample exhibits excellent activity in DME carbonylation *** and DFT studies reveal that this strengthened acidity facilitates the adsorption of DME and reduces the activation barriers of DME dissociation and acetyl formation,accounting for the improved *** work demonstrates mechanistic insights into the promoting effects of strong acidity on DME carbonylation and offers a promising strategy to precisely control the acidic strength of zeolites.

摘要：Introduction In the past decade,three-dimensional(3D)bioprinting,which precisely deposits bioink composed of the biological materials and the living cells into delicate structures with the living cells encapsulated,has made numerous important advances in tissue engineering and regenerative medicine[1,2].Depending on the printing mechanism,3D bioprinting technologies are generally categorized into four types:inkjet-based bioprinting,microextrusion-based bioprinting,laser-assisted bioprinting,and stereolithography-based bioprinting[3].

摘要：Nanogenerators were first demonstrated by deflecting aligned ZnO nanowires using a conductive atomic force microscopy(AFM)*** output of a nanogenerator is affected by three parameters:tip normal force,tip scanning speed,and tip *** this work,systematic experimental studies have been carried out to examine the combined effects of these three parameters on the output,using statistical design of experiments.A statistical model has been built to analyze the data and predict the optimal parameter *** an AFM tip of cone angle 70°coated with Pt,and ZnO nanowires with a diameter of 50 nm and lengths of 600 nm to 1μm,the optimized parameters for the nanogenerator were found to be a normal force of 137 nN and scanning speed of 40μm/s,rather than the conventional settings of 120 nN for the normal force and 30μm/s for the scanning speed.A nanogenerator with the optimized settings has three times the average output voltage of one with the conventional settings.

摘要：Cell migration is facilitated by the interaction of living cells and their local *** local topography is one of the key factors regulating cell *** between the surface topography and the cell behaviors is critical to understanding tissue development and *** this study,a dynamic mask photolithography technique has been utilized to fabricate a surface with graded *** has been demonstrated that the cells have been successfully guided to migrate from the sparse zone to the dense *** cell polarization angle has been characterized in both sparse zone and the dense *** to the dense zone,the cells in the sparse zone are more aligned along the direction of the micropillar spacing gradient,which enables the guided cell ***,the effects of the micropillar spacing gradient,micropillar diameter,and micropillar height have been investigated in terms of the cell migration speed and cell spreading ***,two issues significantly affecting the cell migration have been discussed:trapped cells between the micropillars and cell clusters.

摘要：3D solid models for parts with regular-form surfaces (PRFSs) are effectively generated using traditional parametric design techniques. A new model is obtained by changing some parameters defining the model. The parts with free-form surfaces (PFFSs), however, cannot be defined by several parameters. Usually they are defined by some geometric elements like profile curves. The traditional parametric design approaches have not easily dealt with the PFFSs. A method for generating a solid model and an engineering drawing for PFFSs is proposed in this paper: First, the new profiles are generated from input point data. Second, the profile information is extracted from the existing model. Last, the old profiles are replaced with the new profiles. This method can preserve the associative information of the existing model and automatically generate the drawing including views, dimen- sions, and annotations. The proposed method has been implemented using a commercial CAD/CAM system, Unigraphics, and API functions written in C-language, and were applied to the blades of a turbine generator. Some illustrative examples are pro- vided in order to show the effectiveness of the proposed method.

摘要：In order to investigate the design method for a micro centrifugal compressor,which is the most important component of an ultra micro gas turbine,two types of centrifugal impeller with 2-dimensional blade were designed,manufactured and *** impellers have different shapes of hub on the meridional plane with each ***,these types of impeller were made for the 5 times and the 6 times size of the final target centrifugal impeller with the outer diameter of 4mm in order to assess the similitude for the *** comparison among the performance characteristics of the impellers revealed the influence of the meridional configuration on the performance and the similitude of the compressors.

摘要：钾离子电池(PIBs)面临的一个关键问题是设计具有先进结构的负极材料,以实现快速电荷传输以提高钾的存储性能.采用碳二亚胺铁(FeNCN)作为阳极,由于其含有一定数量的共价键且在分子水平上具有稳定的结构,使得储钾系统能够实现优异的电化学性能.FeNCN阳极具有高导电性,带隙接近0 eV,并且由于其共价键结构具有良好的结构稳定性.此外,无定形反应产物也为离子扩散提供了多种途径.因此,FeNCN阳极表现出高可逆比容量(在50 mA g^(-1)电流密度下具有600 mA h g^(-1)比容量),显著的倍率性能和长寿命循环(电流密度为500 mA g^(-1)时拥有400 mA h g^(-1)比容量且超过300次循环).通过理论模拟、X射线原位衍射分析和X射线光电子能谱分析揭示了Fe^(2+)和K^(+)之间的转化反应机理.此外,将FeNCN负极与苝-3,4,9,10-四羧酸二酐正极材料匹配,组装成的全电池在198.6 Wkg^(-1)的功率密度下实现了184.7 W h kg^(-1)的超高能量密度,明显高于以往所有铁基负极的PIBs或钾离子混合电容器.

摘要：The rapid development of information and communication technologies(ICTs)and cyber-physical systems(CPSs)has paved the way for the increasing popularity of smart ***-awareness is an important facet of product *** artifacts,various bio-systems are naturally characterized by their extraordinary *** inspired design(BID)is one of the most commonly employed design ***,few studies have examined the BID of context-aware smart products to *** paper presents a structured design framework to support the BID of context-aware smart *** meaning of context-awareness is defined from the perspective of product *** framework is developed based on the theoretical foundations of the situated function-behavior-structure ontology.A structured design process is prescribed to leverage various biological inspirations in order to support different conceptual design activities,such as problem formulation,structure reformulation,behavior reformulation,and function *** existing design methods and emerging design tools are incorporated into the framework.A case study is presented to showcase how this framework can be followed to redesign a robot vacuum cleaner and make it more context-aware.

摘要：Three-dimensional(3D)-printed scaffolds have attracted considerable attention in recent years as they provide a suitable environment for bone cell tissue regeneration and can be customized in *** many other challenges,the material composition and geometric structure have major impacts on the performance of *** and tricalcium phosphate(HA/TCP),as the major constituents of natural bone and teeth,possess attractive biological properties and are widely used in bone scaffold *** fabrication methods have been investigated in attempts to achieve HA/TCP scaffolds with microporous structure enabling cell growth and nutrient ***,current 3D printing methods can only achieve the fabrication of HA/TCP scaffolds with certain range of microporous *** overcome this challenge,we developed a slurry-based microscale mask image projection stereolithography,allowing us to form a HA/TCP-based photocurable suspension with complex geometry including biomimetic features and hierarchical ***,the curing performance and physical properties of the HA/TCP suspension were investigated,and a circular movement process for the fabrication of highly viscous HA/TCP suspension was *** on these investigations,the scaffold composition was *** determined that a 30 wt%HA/TCP scaffold with biomimetic hierarchical structure exhibited superior mechanical properties and *** proliferation was investigated in vitro,and the surgery was conducted in a nude mouse in vivo model of long bone with cranial neural crest cells and bone marrow mesenchymal stem *** results showed our 3D-printed HA/TCP scaffold with biomimetic hierarchical structure is biocompatible and has sufficient mechanical strength for surgery.

摘要：Microbial cell factories (MCFs) are typical and widely used platforms in biomanufacturing for designing and constructingsynthesis pathways of target compounds in microorganisms. In MCFs, transporter engineering is especially significant forimproving the biomanufacturing efficiency and capacity through enhancing substrate absorption, promoting intracellular masstransfer of intermediate metabolites, and improving transmembrane export of target products. This review discusses thecurrent methods and strategies of mining and characterizing suitable transporters and presents the cases of transporterengineering in the production of various chemicals in MCFs.