摘要：In the process of the design of heat exchangers,it is difficult to establish the factors governing the optimal points of the design objective functions due to the contradictions and uncertainties of the design *** variation of fluid properties is one of the main factors causing this type of *** design methods have not completely solved these *** the present work,based on the logarithmic mean temperature difference,a new heat exchanger design method(called the segmented design method) is proposed which takes into account the variation of fluid properties with respect to the *** this method,the whole heat exchanger is first divided into several *** by applying the principle of the conservation of energy and taking into account the initial conditions as well as the connecting conditions of the adjacent segments,the inlet and outlet temperatures of each segment are ***,the application of the logarithmic mean temperature difference method on each segment defines the heat transfer area.

摘要：在未来的高频系统芯片,特别是片上网络的设计中,知识产权模块之间的联系至为关键,而单壁纳米碳管则是其中一种很有前景的纳米结构。电路及系统尺寸的不断缩减限制了对1000 GH级别高频信号特征的利用。本文针对不同结构构型的单壁纳米碳管,对高质量互联中四项重要的四项电参数——阻抗,传播常量,电流密度以及信号延时进行了推导。每个参数均表现出了对其设计互联频率范围和构型的强相关性。与现有理论和实验结果相比,本文所提出的模型在解决下一代高速集成电路互联问题上有其新颖性。

摘要：We discuss the P-V criticality and phase transition in the extended phase space of Born-Infeld AdS(BIAdS) black hole surrounded by quintessence dark energy, where the cosmological constant Λ is identified with the thermodynamical pressure P. Comparing with Van der Waals(VdW)-like SBH/LBH phase transition of Born-Infeld AdS(BI-AdS) black hole, we find that the BI-AdS black hole surrounded by quintessence dark energy possesses lower critical temperature because of parameter a > 0, even disappears since the parameter a taking enough large values leads to Tc ≤ 0. Moreover, the interesting thermodynamic phenomenon of reentrant phase transition(RPT) are also observed,and the quintessence dark energy plays a similar role in this RPT.

摘要：With the application of supercavitation effect, a novel device named rotational supercavitating evaporator(RSCE) was recently designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization and then design three-dimensional blades, numerical simulations are conducted on the supercavitating flows(with cavitation number ranging from 0.055 to 0.315) around two-dimensional planar symmetric wedge-shaped cavitators with different wedge angles varied from 10 to 180 degrees. Proper numerical method for simulating supercavitating flows around planar symmetric cavitator is established, and assessment of k-ε-v2 -f turbulence model in simulating cavitating flows is conducted. It shows that the size of computational domain would affect the simulation result. Empirical formulae for supercavity dimensions about cavitation number at different wedge angles are obtained, which are of significant importance in the subsequent design of three-dimensional blade. The characteristics of resistance at different wedge angles are discussed, which, together with the characteristics of supercavity dimensions, play important roles in the optimal design of RSCE.

摘要：In the present work,a principle of equipartition of entransy dissipation(EoED) for heat exchanger design is established,which says that for a heat exchanger design with given heat duty and heat transfer area,the total entransy dissipation rate reaches the minimum when the local entransy dissipation rate is uniformly distributed along the heat *** the heat transfer coefficient is unfixed,the total entransy dissipation obtained by the EoED principle is less than that obtained by the principle of equipartition of temperature difference(EoTD).Furthermore,the exchanger effectiveness obtained by the EoED principle is larger than that obtained by the EoTD *** the heat transfer coefficient is fixed,the EoED principle is equivalent to the EoTD *** show that the equipartition of entropy production(EoEP) and EoED principles give rise to difference in entropy generation and entransy dissipation for a heat exchanger optimization *** discrepancies are caused by distinct features of entropy production minimization and entransy dissipation minimization principles,the former is to optimize the design of heat exchanger by making the lost available work minimum,while the latter is not involved with heat-work *** is found that the entropy generation number is not suitable for evaluating heat exchanger performance,since it directly depends on the inlet and outlet temperatures of working *** the contrary,the entransy dissipation number is not directly related to the inlet and outlet temperatures of working ***,the entransy dissipation number is more suitable for serving as a criterion to evaluate heat exchanger performance.

摘要：Laser powder bed fusion(LPBF)makes it possible for biodegradable zinc(Zn)to be used to produce customized orthopedic *** this research,we investigate the impact of laser power and scanning speed on the development of surface quality,relative densification,and texture during LPBF of Zn *** laser power was able to decrease melt viscosity and surface tension,which improved the metallurgical bonding between adjacent *** and twisted tracks also became continuous and *** speed could controlmolten-pool temperature to restrain grain natural orientation,achieving various crystal orientations and a weakened ***,it further avoided the thermal expansion and contraction caused by excessive energy storage and accumulation in the matrix,thus reducing the generation of high-dislocation *** a result,by selecting a reasonable laser power and scanning speed,the LPBF parts exhibited a flat surface morphology and a high density over 99.5%.Their average hardness,mechanical strength,and elongation reached 50.2 HV,127.8 MPa,and 7.6%,***,the parts displayed a moderate degradation rate and excellent osteogenic *** these results provide a basis for selecting process parameters to optimize the comprehensive properties of LPBF-processed Zn parts for biodegradable applications.

摘要：In this paper,by taking the water-water balanced counterflow heat exchanger as an example,the entransy dissipation theory is applied to optimizing the design of heat *** certain conditions,the optimal duct aspect ratio is determined *** the heat transfer area or the duct volume is fixed,analytical expressions of the optimal mass velocity and the minimal entransy dissipation rate are *** results show that to reduce the irreversible dissipation in heat exchangers,the heat exchange area should be enlarged as much as possible,while the mass velocity should be reduced as low as possible.

摘要：显示器作为视觉信息的载体,在我们的日常生活中发挥着不可或缺的作用.近年来,随着微显示产品的市场需求不断扩大,与高分辨率自发光显示器密切相关的科研成果数量呈现快速增长趋势,国内外各大研究机构对显示分辨率的进一步提高、驱动模块的设计与开发、材料及器件结构的优化和微型显示器的应用研究显著增加.然而,尚无综述对这三种显示技术相关的大量工作进行较为全面的梳理和总结.本综述的主要内容如下:(1)高分辨率显示器件技术路线的工艺划分;(2)各高分辨率自发光显示工艺的具体细节,以及其他有潜力应用于高分辨发光显示中的精细图案化技术;(3)各方案的优势和局限性讨论;(4)高分辨显示现存问题与挑战的总结.本综述有望为微型显示的产业界和学术界带来有价值的参考.

摘要：Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, usually exhibit reversible host rearrangement between P-type and O-type stacking upon charge/discharge. Herein we demonstrate that such host rearrangement is unfavorable and can be suppressed by introducing transition-metal ions into sodium layers. The electrode with stabilized P3-type stacking delivers superior rate capability, high energy efficiency, and excellent cycling performance. Owing to the cation-mixing nature, it performs the lowest lattice strain among all reported cathodes for sodium-ion batteries. Our findings highlight the significance of a stable host for sodium-ion storage and moreover underline the fundamental distinction in material design strategy between lithium-and sodium-ion batteries.

摘要：In the complex multicore chip system,network on-chip(NoC)is viewed as a kind of system interconnection that can substitute the traditional interconnect networks,which will improve the system performance and communication *** regard to the complex and large scale NoC,simple and efficient routing nodes are the critical factors to achieve low-cost and low-congestion communication *** paper proposes an unbuffered switch architecture and makes detailed analysis of the mechanism of buffer in the switch *** to the simulation results,the S-mesh using the unbuffered switch architecture is better in terms of the optimal performance in message latency than some typical NoC architectures,such as 2D-mesh,Fat-tree,Butterfly,Octagon and so *** synthesis results of design compiler indicate that the unbuffered switch has obvious advantages of achieving cost and operating speed for the chips.