摘要：Recent developments in organoid culture technologies have made it possible to closely recapitulate intrinsic characteristics of different tissues under in vitro *** organoids act as a translational bridge between the traditional 2D/3D cultures and the in vivo models for studying the tissue development processes,disease modeling,and drug *** and tissue-specific extracellular matrix have been shown to support organoid development,efficiently;however,their chemically undefined nature,non-tunable properties,and associated batch-to-batch variations often limit reproducibility of the assembly *** this regard,chemically defined platforms offer wider opportunities to optimize and recreate tissue-specific *** present review delineates the current research trends in this sphere,focusing on material perspective and the target tissues(e.g.,neural,liver,pancreatic,renal,and intestinal).The review winds up with a discussion on the current limitations and future perspective to provide a basis for future research.

摘要：Changes in precipitation minus evaporation （P-E） are analyzed to investigate the possible impacts of climate change on water resource conditions in China. Simulations of SRES A1B and 20C3M scenarios from the WCRP CMIP3 GCMs are employed in the study. Time slice analysis shows that there would be more annual mean P-E across China in 2040-2055 and 2080-2099, compared to 1980-1999, with the largest percentage change over Northwest China and the Bohai Rim area. Precipitation and evaporation would also increase over entire China during these two periods. Annual mean P-E, precipitation, and evaporation averaged over the whole China and its eight sub-areas all yield generally upward trends during the 21st century. This indicates that on annual mean scale, the global warming related precipitation dominates the hydroclimate conditions in China. On seasonal mean scale, although precipitation is projected to increase over China, P-E exhibits both decreasing and increasing trends over certain regions of China. This suggests that the variation of global warming related evaporation dominates hydroclimate conditions over some parts of China, especially in northern China. Therefore, in hydroclimate condition projections, considering both evaporation and precipitation changes should be more reasonable than considering only precipitation.

摘要：An analysis has been completed for a comprehensive set of vertical,dilute-phase pneumatic conveying pressure drop data from an investigation by *** data were collected in the established flow region for eight different materials conveyed in 0.05-,0.10-,0.20-m internal diameter,20-m tall steel *** velocities derived from the pressure drop data were used to develop an equation of motion that includes terms for pipe diameter,terminal velocity,coefficient of restitution,and particle *** best data fit was achieved using the actual gas density and the actual gas velocity adjusted for *** the terminal velocity for voidage,an approach recommended by many investigators,did not improve the fit for reasons identified by the present *** the equation of motion,particle velocities were predicted and used to calculate total pressure drops that are within±15%of the measured *** calculated values also produce the characteristic trough-shaped total pressure drop curves allowing the minimum pressure drop gas velocity to be determined without recourse to a separate correlation.A comparison with other studies using shorter risers indicates that data from these studies likely include acceleration effects.A separate study will investigate this observation further.

摘要：A new transparent photovoltaic panel composed of a luminescent solar concentrator and Al/BaTiO3/ZnO/Pt ferroelectric solar cells is presented,in which a portion of the incoming solar illumination is converted by the fluorophores to ultraviolet(UV)light which is then absorbed by ***,the solar cells are simulated using ***,the panel is modelled based on the obtained solar cell *** panel would be of great importance for building integrated photovoltaics domain because of its high transparency.

摘要：Surgical meshes have been employed in the management of a variety of pathological conditions including hernia,pelvic floor dysfunctions,periodontal guided bone regeneration,wound healing and more recently for breast plastic surgery after *** common pathologies affect a wide portion of the worldwide population;therefore,an effective and enhanced treatment is crucial to ameliorate patients’living conditions both from medical and aesthetic points of *** present,non-absorbable synthetic polymers are the most widely used class of biomaterials for the manufacturing of mesh implants for hernia,pelvic floor dysfunctions and guided bone regeneration,with polypropylene and poly tetrafluoroethylene being the most *** prostheses,such as surgical grafts,have been employed mainly for breast plastic surgery and wound healing *** the advantages of mesh implants to the treatment of these conditions,there are still many drawbacks,mainly related to the arising of a huge number of post-operative complications,among which infections are the most *** a mesh that could appropriately integrate with the native tissue,promote its healing and constructive remodelling,is the key aim of ongoing research in the area of surgical mesh *** this end,the adoption of new biomaterials including absorbable and natural polymers,the use of drugs and advanced manufacturing technologies,such as 3D printing and electrospinning,are under investigation to address the previously mentioned challenges and improve the outcomes of future clinical *** aim of this work is to review the key advantages and disadvantages related to the use of surgical meshes,the main issues characterizing each clinical procedure and the future directions in terms of both novel manufacturing technologies and latest regulatory considerations.

摘要：A hybrid conceptual design approach was introduced in this study to develop a conceptual design of oil palm polymer composite automotive crash box(ACB). A combination of theory of inventive problem solving(TRIZ), morphological charts and biomimetics was applied where the foremost requirements in terms of the material characteristics, function specifications, force identification, root cause analysis, geometry profile and design selection criteria were considered. The strategy was to use creations of nature to inspire five innovative conceptual designs of the ACB structure and the AHP method was applied to perform the pairwise analysis of selecting the best ACB conceptual design. A new conceptual design for a composite ACB was conceived bearing in mind the properties of natural fibre, unlike those of conventional materials such as steel alloys and aluminium alloys. The design with the highest ranking(26.6 %) was chosen as the final conceptual design, which was the one with a honeycomb structure for the outermost profile, reinforced with a spider web structure inside the part, supported by fibre foam structure extracted from the woodpecker sponge tissue at the centre to maximize the energy absorption capability. The new design could solve the problem of bending collapse which is a major cause of failure to absorb maximum impact energy for ACB during collision. However, the final conceptual design will still need several modifications for production and assembly purposes, which will be completed in a further study.

摘要：Three-dimensional(3D)bioprinting has been used widely for the construction of hard tissues such as bone and ***,constructing soft tissues with complex structures remains a *** this study,complex structures characterized by both tunable elastic modulus and porosity were printed using freeform reversible embedding of suspended hydrogels(FRESHs)printing methods.A mixture of alginate and gelatin was used as the main functional component of the *** analysis showed that this bioink possesses shear thinning and shear recovery properties,supporting both cryogenic and FRESH printing *** printing capabilities and limitations of cryogenic and FRESH printing were then analyzed by printability tests.A series of complex structures were printed by FRESH printing methods which could not be realized using conventional *** tests and scanning electron microscopy analysis showed that the printed structure is of excellent flexibility and could be applied in various conditions by adjusting its mechanical modulus and porosity.L929 fibroblast cells maintained cell viability in cell-laden-printed structures,and the addition of collagen further improved the hydrogels’***,all results provided useful insight into the building of human soft tissue organ blocks.

摘要：The application of a digital modelling method that can faithfully take account of three-dimensional shape and inherent physical and chemical properties of each particulate component provides an essential tool in decommissioning design. This is useful in handling of high, medium and low level radioactive waste. The processes involve making decisions on where to cut existing plant components and then how to pack these components into boxes, which are then cemented and kept for long term storage as the level of radioactive declines with time. We illustrate the utility of the method and its ability to take data at plant scale （m-scale） and then deduce behaviours at sub millimetre scale in the packed containers. A variety of modelling approaches are used as a part of this approach including cutting algorithms, geometric and dynamic （distinct element） force models, and lattice Boltzmann methods. These methods are applicable to other complex particulate systems including simulation of waste, building recycling, heap leaching and related minerals processes. The paper introduces the basic concepts of this multi-scale and multi-model approach.

摘要：介绍了目前几种常见的船桥碰撞力估算公式,并采用这些公式分别计算了四艘三峡标准散货船在各种航速下撞击桥墩的碰撞力。根据三峡标准散货船的设计图纸建立船体有限元模型,通过数值模拟计算了不同吨级、船速下的船桥碰撞力曲线。在桥梁设计时,该曲线可以为该类船舶一桥墩碰撞力计算及评估提供参考。结合经验公式的推导过程,通过船桥碰撞力经验公式与有限元数值仿真分析计算结果表明,铁路桥涵设计规范的船桥碰撞力公式更适合于斜艏500至3 000 t级散货船,而美国公路桥梁设计规范的船桥撞击力计算公式对该类型吨级船舶的碰撞力结果偏大。

摘要：作为机械产品设计和制造过程中的一项重要内容,计算机辅助公差设计(CAT)是CAD/CAPP/CAM集成的关键技术,是国内外先进制造技术发展中亟需解决的问题。计算机辅助公差设计覆盖面非常广泛,涵盖公差规范和标准化、设计/制造工艺/产品生命周期管理中的公差设计、检测与测量以及功能公差设计。本文首先简要分析这些热点问题的研究进展情况,其次介绍本专辑收集的第13届国际生产工程科学院计算机辅助公差设计会议中的最新研究成果,分析该领域的最新研究进展,希望能帮助读者了解相关研究工作并促进研究人员开展讨论,进一步实现计算机辅助公差设计中的关键技术的突破,促进CAD/CAPP/CAM的集成。