摘要：Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect *** this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser *** results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in *** experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus ***,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.

摘要：It has made significant progress in catalyst andreactor design for commercial current densities in CO_(2) electroreduction(CO_(2)ER).However,these catalyst systems haverarely been applied for a C2 gas product of ethane due to itscommonly inferior selectivity relative to other C1 and ***,bamboo-like amorphous Ni(OH)_(2) nanotubes wrapped Cu nanoparticles composite(Cu NPs@aNi(OH)_(2)NTs)are constructed for selective CO_(2)ER to ethane ina flow *** unique structure of Cu NPs@a-Ni(OH)_(2) NTsprovides a confined geometry to improve the adsorption of thereactive *** interface of Cu NPs and a-Ni(OH)_(2) NTs isstabilized by generating some NiOH *** producedCu@NiOH interface enhances the activation of CO_(2) to*C*OOH and strengthens the adsorption of*COL on Cu sitefor more*COH formation and its dimerization for finalethane ***,amorphous Ni(OH)_(2) nanotubes promote water dissociation for the hydrogenation ofcarbonous intermediates,contributing to ethane *** synthesized Cu NPs@a-Ni(OH)_(2) NTs can reach a Faradaicefficiency of 48.3%and a partial current density of−226.7 mA cm^(−2) for ethane at−0.7 V in a flow cell,with aremarkable stability for 24 *** work provides a rationalstrategy to engineer Cu-based composite for selective CO_(2)ERto ethane in a flow cell.

摘要：Multi-component mixture(MCM) is a complicated chemical system that contains a great deal of mixture rays with various mixture ratios, and each ray includes many mixtures with different concentration ***, in combined toxicity field, almost all studies on MCM focus on the mixtures designed by the equivalenteffect concentration ratio(EECR) procedure. However, the EECR mixtures cannot represent the whole mixture system because the EECR mixtures are located on one mixture ray in concentration space formed by multiple components. In our view, some optimal experimental design such as the uniform design(UD) should be used to effectively select many representative mixture rays from the MCM system,instead of single EECR ray. The uniform design ray(UDray) integrating UD idea with fixed-ratio ray design can systematically and comprehensively measure the combined toxicity changes in the MCM system. This review introduces the operation method, construction of uniform table and corresponding usable table, and some cases of application of the UD-ray to help readers easily use UD-ray in their MCM toxicity assessment.

摘要：A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe both the control behavior within a repetition period and the learning process taking place between periods. Next, by converting the designing problem of repetitive controller into one of the feedback gains of reconstructed variables, the stable condition was obtained through linear matrix inequality(LMI) and also the gain coefficient of repetitive system. Numerical simulation shows an exceptional feasibility of this proposal with remarkable robustness and tracking speed.

摘要：By using coordinate transformation method, this paper obtains an useful equation of designing meta-material cloaks embedded in anisotropic medium. This equation is the generalization of what was introduced early by Pendry et al （2006 Science 312 1780） and can be more widely used. As an example of its applications, this paper deduces the material parameter equation for cylinder cloaks embedded in anisotropic medium, and then offers the numerical simulation. The results show that such a cylinder cloak has perfect cloaking performance and therefore verifies the method proposed in this paper.

摘要：In this study, the effects of length-width ratio and diversion trench of the spacer on the fluid flow behavior in an electrodialyzer have been investigated through CFD simulation method. The relevant information, including the pressure drop, velocity vector distribution and shear stress distribution, demonstrates the importance of optimized design of the spacer in an electrodialysis process. The results show width of the diversion trench has a great effect on the fluid flow compared with length. Increase of the diversion trench width could strength the fluid flow, but also increase the pressure drop. Secondly, the dead zone of the fluid flow decreases with increase of length-width ratio of the spacer, but the pressure drop increases with the increase of length-width ratio of the spacer. So the appropriate length-width ratio of the space should be moderate.

摘要：The distribution of thermal stresses in functionally graded polycrystalline diamond compact (PDC) and in single coating of PDC are analyzed respectively by thermo-mechanical finite element analysis (FEA). It is shown that they each have a remarkable stress concentration at the edge of the interfaces. The diamond coatings usually suffer premature failure because of spallation, distortion or defects such as cracks near the interface due to these excessive residual stresses. Results showed that the axial tensile stress in FGM coating is reduced from 840 MPa to 229 MPa compared with single coating, and that the shear stress is reduced from 671 MPa to 471 MPa. Therefore, the single coating is more prone to spallation and cracking than the FGM coating. The effects of the volume compositional distribution factor (n) and the number of the graded layers (L) on the thermal stresses in FGM coating are also discussed respectively. Modelling results showed that the optimum value of the compositional distribution factor is 1.2, and that the best number of the graded layers is 6.

摘要：Titanium(Ti)and titanium alloys have become widely used as biomedical materials in orthopedics because of their good machinability,corrosion resistance,low elastic modulus and excellent ***,when Ti-based implants are used for bone repair and replacement,they are easy to cause bacteria adhesion and aggregation,which leads to postoperative *** addition,Ti and its alloys,as bio-inert materials,cannot induce desirable tissue responses such as osseointegration after implantation,which will eventually lead to implant *** bacterial infection and lack of osseointegration directly lead to the failure of implantation surgery and are not conductive to the long-term service of titanium-based ***,researchers have made many attempts to focus on the surface modification of multifunctional Ti-based implants to endow them with both antibacterial activity and simultaneous osteoinductive *** this review,we primarily highlighted the recent progresses in the surface design of Ti implants with both antimicrobial and osteoinductive properties for orthopedic ***,the challenges for treating implant-associated infections were briefly introduced such as the emergence of antibiotic resistance,the formation of biofilms,and the construction of cell-selective *** of the essential fundamentals were concisely introduced to address these emerging ***,we intended to elaborate the potential strategies of multifunctional surface design to endow good osseointegration for antibacterial Ti implants and highlighted the recent advances of the *** hope that this review will provide theoretical basis and technical support for the development of new Ti implant with antibacterial and osteogenic functions.

摘要：Designing bio-inspired flow fields holds great potential in improving the performance of Proton Exchange Membrane Fuel Cell(PEMFC).Two kinds of biological prototypes are widely used:plant prototype and animal *** remains a question which one of these prototypes is more appropriate for the scenario of ***,a comparative study was conducted to compare bionic flow fields based on animal and plant ***,a Corn Leaf Vein Mathematical Model(CLMM)was established by extracting structural parameters from corn leaves of two growth *** the obtained CLMM and well-known Murray’s law were employed to design bionic flow fields corresponding to the plant and animal prototypes,respectively,which have been subsequently compared by numerical *** results demonstrate that the flow field guided by Murray’s law outperforms the counterpart based on the structural parameters of CLMM in terms of PEMFC net output power,mass transport,water management and pressure drop,suggesting that animal circulation system is more suitable to the bionic flow field design of PEMFC than plant leaf *** work may also offer valuable insights into the design of other flow fields related to electrochemical energy conversion.

摘要：The detection of low-level light is a key technology in various experimental scientific studies. As a photon detector, the silicon photomultiplier （SiPM） has gradually become an alternative to the photomultiplier tube （PMT） in many applications in high-energy physics, astroparticle physics, and medical imaging because of its high photon detection efficiency （PDE）, good resolution for single-photon detection, insensitivity to magnetic field, low operating voltage, compactness, and low cost. However, primarily because of the geometric fill factor, the PDE of most SiPMs is not very high; in particular, for those SiPMs with a high density of micro cells, the effective area is small, and the bandwidth of the light response is narrow. As a building block of the SiPM, the concept of the backside-illuminated avalanche drift detector （ADD） was first proposed by the Max Planck Institute of Germany eight years ago; the ADD is promising to have high PDE over the full energy range of optical photons, even ultraviolet light and X-ray light, and because the avalanche multiplication region is very small, the ADD is beneficial for the fabrication of large-area SiPMs. However, because of difficulties in design and fabrication, no significant progress had been made, and the concept had not yet been verified. In this paper, preliminary results in the design, fabrication, and performance of a backside-illuminated ADD are reported; the difficulties in and limitations to the backside-illuminated ADD are analyzed.