摘要：Small long-life transportable high temperature gas-cooled reactors(HTRs) are interesting because they can safely provide electricity or heat in remote areas or to industrial users in developed or developing *** paper presents the neutronic design of the U-Battery,which is a 5 MWth block-type HTR with a fuel lifetime of 5–10 *** a reactor pressure vessel diameter of less than 3.7 m,some possible reactor core configurations of the 5 MWth U-Battery have been investigated using the TRITON module in SCALE *** neutronic analysis shows that Layout 12×2B,a scattering core containing 2 layers of 12 fuel blocks each with 20% enriched235U,reaches a fuel lifetime of 10 effective full power years(EFPYs).When the diameter of the reactor pressure vessel is reduced to 1.8 m,a fuel lifetime of 4 EFPYs will be achieved for the 5 MWth U-Battery with a 25-cm thick graphite side *** 6×3 and 6×4 with a 25-cm thick BeO side reflector achieve a fuel lifetime of 7 and 10 EFPYs,*** comparison of the different core configurations shows that,keeping the number of fuel blocks in the reactor core constant,the annular and scattering core configurations have longer fuel lifetimes and lower fuel cost than the cylindrical ***,for the 5 MWth U-Battery,reducing the fuel inventory in the reactor core by decreasing the diameter of fuel kernels and packing fraction of TRISO particles is more effective to lower the fuel cost than decreasing the 235U enrichment.

摘要：Technological and economic opportunities,alongside the apparent ecological benefits,point to biodesign as a new industrial paradigm for the fabrication of products in the twenty-first *** presented work studies plant roots as a biodesign material in the fabrication of self-supported 3D structures,where the biologically and digitally designed materials provide each other with structural *** a material-driven design approach,we present our systematic tinkering activities with plant roots to better understand and anticipate their responsive *** helped us to identify the key design parameters and advance the unique potential of plant roots to bind discrete porous *** illustrate this binding potential of plant roots with a hybrid 3D object,for which plant roots connect 600 computationally designed,optimized,and fabricated bioplastic beads into a low stool.

摘要：为进一步说明之前的文章,提出了支持面向特定系统表现特征(system manifestation feature,SMFs)的信息管理和构成系统模型编程的信息模式构造(information schema construct,ISCs)。首先,简要介绍了(1)利用SMFs进行具体化设计的一般过程,(2)创建基因型和表型SMFs的步骤,(3)表型SMFs实例化的具体步骤,以及(4)系统模型管理和处理的步骤。接着,讨论了表型SMFs实例化所需的信息块,提出了为实现SMFs实例化而设计的ISCs。然后,讨论了与系统建模相关的信息管理问题。在研究方法上,系统建模包括(1)在模型空间中放置表型SMFs,(2)针对所需架构和操作,组合所放置的表型SMFs,(3)参数赋值以及约束条件符合程度检查,以及(4)在基于SMFs的数据仓中存储系统构建模型。研究的最终目标是开发一个支持信息物理系统(cyber-physical systems,CPSs)建模的基于SMFs的工具箱。

摘要：In analog audio equalizer, the filters are constructed by op-amplifiers and discrete components. Being influenced by its discrete capabilities, audio equalizer has many disadvantages. Meanwhile, pure digital audio equalizer has got better performance and stability, but its cost and price are too high. So digital audio equalizer only has its application in upscale domain. A new design method for audio equalizer is proposed, which attempts to design and realize a high precision and high SNR (signal noise ratio) digital audio equalizer system based on field programmable analog array (FPAA) and micro-controller unit. This design confirms that design speed and performance will be greatly enhanced when FPAA technology is applied to analog design domain.

摘要：The finite element system CAPA-3D was utilized as the numerical simulation platform,two structural FE models of orthotropic steel bridge decks were set up,the static and dynamic FE simulations under different loading conditions were carried out,the special attention was given to identify the critical wheel load location,and the maximum tensile stress distribution and the variation of strain rate inside membrane *** result shows that the FE models are capable of simulating the realistic behavior of orthotropic steel *** distributions of strains and stresses inside the surfacing materials depend highly on wheel load level,wheel load frequency,wheel position,membrane bonding strength as well as the thicknesses and characteristics of surfacing *** maximum tensile stress of membrane layers is found around 0.4MPa,which coincides with the minimum requirement for the adhesive bonding strength of membrane material proposed by the standards NF P98-282and *** maximum membrane strain rate is found around 0.1,which is an important information that can be utilized for the characterization of membrane products.1tab,28figs,7refs.

摘要：粉末床熔融增材制造技术已应用于功能梯度材料的制造.文献中报道了一种材料成分沿垂直于粉末铺粉方向变化的新设计.基于此设计,本工作采用离散单元数值模拟研究了两种密度差异较大的金属粉末在铺粉过程中颗粒的偏析情况.结果发现,在铺粉过程中,较大密度粉末(重颗粒)一侧的铺粉量小于较小密度粉末(轻颗粒)的一侧的铺粉量.这种现象表明重颗粒从粉末密度大的一侧向粉末密度较小的一侧扩散.这种扩散受铺粉速度影响较大,铺粉速度越快,扩散越明显.但粉末层厚度对扩散影响不大.结果还表明,重颗粒与轻颗粒间的粒径差异影响扩散较大,减小重颗粒的粒径可能是控制颗粒偏析的一种方案.

摘要：An ultra-thin multi-LED package is designed, manufactured and its thermal performance is character- ized. The objective of this study is to develop an efficient thermal modelling approach for this system which can be used for optimization of the thermal-performance of future ultra-thin designs. A high-resolution thermal imaging camera and thermocouples were used to measure the temperature distribution of the multi-LED package and the LED-die temperature for different operating powers. Finally, we compare the thermal measurements with the finite element simulation results. It is concluded that the modelling approach can assist in the thermal optimization of future multi-LED package designs.

摘要：The paper presents a dynamic model intervened by urban design for the decision-making of land development intensity, which expresses the inherent interaction mechanism between lands based on the evaluation of land attributes and their similarity relationship. Each land unit is described with several factors according to their condition and potential for development, such as land function, accessibility, historical site control, landscape control, and so on. Then, the dynamic reference relationship between land units is established according to the similarity relationship between their factors. That means lands with similar conditions tend to have similar development intensities, which expresses the rule of the spontaneous urban development. Therefore, the development intensities of the pending lands can be calculated by the confirmed ones. Furthermore, the system can be actively intervened by adjusting the parameters according to urban design or planning intentions. And the reaction of the system offers effective support and reference for reasonable decision. The system with multiple intervention input is not only a credible tool for deriving development intensities, but also a platform to activate urban design conception. Above all, the system as a socio-technical tool integrates the optimization of form, function and environment, and embodies the principle of impersonality, justice and flexibility in the decision of land development intensity.

摘要：The developments in power transmission via HVDC networks are fast,especially in Western Europe and *** challenges that we are confronted with are huge and considerable research and development efforts are *** attention is needed for high voltage direct current(HVDC)and ultra-high voltage dc(UHVDC)underground *** the highest voltage levels,we are still dependent upon classic technology based on mass-impregnated paper used in line commutated converter(LCC)***,more and more polymeric type cables are appearing on the market,as yet mainly for voltage source converter(VSC)*** financial,environmental and technical reasons the full focus is now on polymeric type cables,for use in LCC or VSC *** this paper,a closer look is taken at the interfaces in polymeric cable systems,*** the cables and in the cable *** the design process,we are challenged by the presence of interfaces from an electrical and thermal point of *** the field of electrical insulation,the interfaces between different materials are generally considered the weakest parts of the equipment and under DC stresses the situation becomes even more complex due to the charge dynamics at the ***,the design of(U)HVDC accessories has become a challenge if not a *** paper focuses on some of the important electrical and thermal aspects of interfaces in HVDC polymeric *** is discussed where we lack knowledge and where we may benefit from other scientific

摘要：A knock-down factor is commonly used to take into account the obvious decline of the buckling load in a cylindrical shell caused by the inevitable imperfections. In 1968, NASA guideline SP-8007 gave knock-down factors which rely on a lower-bound curve taken from experimental data. Recent research has indicated that the NASA knock-down factors are inclined to produce very conservative estimations for the buckling load of imperfect shells, due to the limitations of the computational power and the experimental skills available five decades ago. A novel knock-down factor is proposed composed of two parts for the metallic stiffened cylinders. A deterministic study is applied to achieve the first part of the knock-down factor considering the measured geometric imperfection, the other types of imperfections are considered in the second part using a stochastic analysis. A smeared model is used to achieve the implementation of the measured geometric imperfection for the stiffened cylinder. This new robust and less conservative design for the stiffened cylinders is validated by using test results.