摘要：A design of polarization-maintaining retro-reflectors （PMRRs） for folded-path applications is proposed and analyzed. The prism-based scheme enables the output light, which is parallel to the input, to have an identical state of polarization. The principle of the design is theoretically verified, and the related error is analyzed due to possible manufacturing imperfection. The maximum spatial angle error is ±2.75°. The effect on the extinction ratio and insertion loss is also discussed, which further proves the design＇s feasibility in practical applications.

摘要：With the aim of developing a low-cost and efficient visible-light-driven photocatalyst for radical polymerization,iron-chelating polyimide networks(Fe@MPI)was fabricated by firstly synthesizing photoactive melamine-containing polyimide(MPI)networks and then incorporating Fe(III)cations into the polymer ***@MPI exhibits a wide absorption spectrum ranging from 220 to 1250 nm and 3.5 times higher photocurrent intensity as compared with the pristine *** on its excellent photo-electric properties,Fe@MPI was employed as a recyclable heterogeneous catalyst,providing sufficient activity for the visible-light driven radical polymerization to synthesize poly(methyl methacrylate)with molecular weight up to 31.×10^4 g *** advantage of the heterogeneous nature of the catalyst,Fe@MPI could be facilely regenerated from the polymerization solution by filtration without an obvious loss of its *** research provides a novel recyclable catalyst for visible-light driven radical polymerization.

摘要：This paper mainly discusses the power and solidarity among participants in the community correction discourse from sociolinguistic perspective by adopting the methodology of conversation *** the comparative study of the steps of Initial Evaluation and Entry Ceremony in community correction,this paper analyses the power and solidarity in the features of adjacency pair and turn-taking,and finds that the step of Initial Evaluation is relatively negotiable and represents the social relationship of solidarity,while the step of Entry Ceremony stresses more on social distance and power *** reasons that cause the power and solidarity in the Initial Evaluation and the Entry Ceremony from the perspective of social identity and social purposes are also explored.

摘要：Three-dimensional(3D)tumor models prepared from patient-derived cells have been reported to imitate some of the biological development processes of in situ tumors in *** 3D tumor models share several important characteristics with their in vivo tumor ***,their applications in tumor modeling,drug screening,and precision-targeted treatment are ***,the establishment of tumormodels is subject to several challenges,including advancements in scale size,repeatability,structural precision in time and space,vascularization,and the tumor ***,bioprinting technologies enabling the editorial arrangement of cells,factors,and materials have improved the simulation of tumormodels in *** the 3D bioprinted tumor models,the organoidmodel has been widely appreciated for its advantages of maintaining high heterogeneity and capacity for simulating the developmental process of tumor *** this review,we outline approaches and potential prospects for tumor model bioprinting and discuss the existing bioprinting technologies and bioinks in tumor model *** multidisciplinary combination of tumor pathology,molecular biology,material science,and additive manufacturing will help overcome the barriers to tumor model construction by allowing consideration of the structural and functional characteristics of in vitro models and promoting the development of heterogeneous tumor precision therapies.

摘要：Two kinds of semi-solid samples of AZ80−0.2Y−0.15Ca(wt.%)(AZ80M)magnesium alloy were prepared by semi-solid isothermal heat treatment of materials with and without equal channel angular pressing(ECAP)*** microstructures of initial and semi-solid treated samples were compared and *** results showed a significant difference in the liquid phase distribution between three-pass ECAP processed(3P)and as-received samples during the isothermal heating *** semi-solid 3P sample showed a more uniform liquid distribution due to its smaller dihedral ***,the coarsening processes of solid grains of as-received and 3P samples were dominated by the coalescence and Ostwald ripening mechanism,*** difference of coarsening processes was mainly related to the proportion of the high-angle grain boundaries in materials,which further affected the evolution behavior of the liquid pools.

摘要：Two-dimensional(2D)metal oxides and chalcogenides(MOs&MCs)have been regarded as a new class of promising electro-and photocatalysts for many important chemical reactions such as hydrogen evolution reaction,CO_(2) reduction reaction and N2 reduction reaction in virtue of their outstanding physicochemical ***,pristine 2D MOs&MCs generally show the relatively poor catalytic performances due to the low electrical conductivity,few active sites and fast charge ***,considerable efforts have been devoted to engineering 2D MOs&MCs by rational structural design and chemical modification to further improve the catalytic ***,we comprehensively review the recent advances for engineering technologies of 2D MOs&MCs,which are mainly focused on the intercalation,doping,defects creation,facet design and compositing with functional ***,the relationship between morphological,physicochemical,electronic,and optical properties of 2D MOs&MCs and their electro-and photocatalytic performances is also systematically ***,we further give the prospect and challenge of the field and possible future research directions,aiming to inspire more research for achieving high-performance 2D MOs&MCs catalysts in energy storage and conversion fields.

摘要：No shale-rock physical model has been established in the observation coordinate *** this end,this paper carried out anisotropic wave velocity tests on shale rock and compared the Thomsen,Daley,and Berryman solutions to characterize anisotropic acoustic wave ***,the Daley solution was *** on basic rock physical models,such as SCA and DEM methods,and combined with the Daley solution,an anisotropic shale-rock physical model was established in the observation coordinate system and applied in Well B1 in the Luzhou area,Sichuan *** research conclusions were as follows:*** the samples from the same core,the P-wave velocities in three directions were in the order VP11>VP45>VP33,shear wave velocity VS11 was the largest,but VS33 and VS45 did not follow the law of Vs33>Vs45 for some samples;*** Daley solution,which not only considers the accuracy requirements but also has a complete expression of P-,SV-,and SH-waves,is most suitable for characterization of anisotropic wave velocity in this study area;*** rock physical model constructed in the observation coordinate system has high accuracy,in which the absolute value of the relative error of the P-wave slowness was between 0%and 5.05%(0.55%on average),and that of shear-wave slowness was between 0%and 6.05%(0.59%on average);*** acoustic waves recorded in Well B1 in the observation coordinate system were very different from those in the constitutive coordinate *** relative difference of the P-wave was between 6.76%and 30.84%(14.68%on average),and that of the S-wave was between 7.00%and 23.44%(13.99%on average).The acoustic slowness measured in the observation coordinate system,such as in a deviated well or a horizontal well section,must be converted to the constitutive coordinate system before it can be used in subsequent engineering applications;*** anisotropic shale-rock physical model built in the observation coordinate system proposed in this paper can provide basic data a

摘要：Objective: To repair rabbit tendon defects with tissue engineering method. Methods: The third passage of fetal skin fibroblast cells was labeled with 5 bromo 2 deoxyuridine (Brdu) and then seeded on human amnion extracellular matrix ( HA ECM ). Using 1 cm long Achilles tendon defects as repairing models in the experimental group, tendon defects were core bridged with polydioxanone (PDS) and then capsulated with the complex of fibroblasts HA ECM . In the control group I, defective tendons were sutured with PDS following the former procedure and capsulated with HA ECM (without fibroblasts). In the control group II, only PDS was applied to connect the defective tendons. Gross examination, light microscopy, scanning electronmicroscopy and biomechanical measurement of the repaired tendons were respectively performed at postoperative 1, 2, 3 month as well as immunohistochemical examination. Results: The optimal cell concentration for seeding fibroblasts was 3.5 ×10 6 cells/ml. Cells grew well and radiated or paralleled on HA ECM . Immunohistochemistry showed that the labeled seed fibroblasts played an important role in tendonization. The results of light microscopy, electron microscopy, and biomechanical assessment suggested that the rate and quality of tendonization in the experimental group was superior to those of the control group I and II. The tensile strength in the experimental group was the greatest, the next was in the control group I, and the worst in the control group II (P< 0.05 ). Conclusions: HA ECM is the excellent carrier for fibroblasts. Fibroblasts HA ECM complex has the capability to repair tendon defect and to tendonize with rapid rate and good performance three months after operation. Its tensile strength is 81.8 % of that of normal tendon.

摘要：To overcome the current difficulties of high-precision machining and the high manufacturing and maintenance costs of spherical seals for deep-water drilling ball joints,a new spherical seal technique is proposed in this *** spherical seal is mainly composed of silicone rubber and polytetrafluoroethylene(PTFE).Rational structural design makes the seal independent from the ball and other components,making it easy to replace if leakage occurs at its *** can elastically deform over a certain deformation range,which guarantees that two sealing surfaces fit tightly together.O-Ring and PTFE elasticity makes up for any lack of accuracy during spherical machining and decreases the machining precision requirements for spherical *** a finite element technique and nonlinear theory,the performance of the spherical seal under the influence of various factors is *** results show that the spherical seal designed in this paper exhibits excellent sealing performance under lowtemperature and high-pressure *** spherical seal,a combination of an O-ring and PTFE,has the advantages of cheap manufacturing and maintenance costs and excellent sealing performance.

摘要：Filtering media is anything placed in a filter that changes the quality of water flowing through *** the variety of media available,proper selection of filter media is of great importance for filter *** glass is evaluated as an alternative to silica sand in media filters and is an effective medium with the advantages of lower cost than silica sand,more environmental friendliness as it is a recycled product,and ease to pulverize into different sizes for specific design ***,the filtration efficiency of regenerated recycled glass is limited by the formation of biofilms on its surfaces due to the large number of microorganisms such as bacteria and algae existing in the *** this study,hydrofluoric(HF)acid etched glass spheres(GSs)modified with polydopamine(PDA)and silver nanoparticles(PDA-AgHF/GSs)were fabricated on the surface of soda-lime GSs by HF etching,crystal in situ growth,and PDA *** etching and the modification of PDA coating imparted good hydrophilicity to PDA-Ag-HF/*** modification of the silver coating also rendered PDA-Ag-HF/GSs excellent antibacterial properties and reduced Chlorella adhesion,and inhibited microorganism growth ability by releasing Ag^+.The catechol functional group on the PDA coating could regulate the Ag^+release by *** antibacterial properties,anti-algae adhesion,and controlled release of Ag^+indicate that PDA-Ag-HF/GS coating can effectively inhibit the formation of biofilm on the surface of the material,providing a new strategy for the formation of anti-biofilm.