Stability Analysis for Projectile with Wrap-Around Fins

Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

基于X射线晶圆在线辐照实验的16 nm n-FinFETs总剂量效应模型研究

建立了基于X射线晶圆在线辐照实验的16 nm FinFET总剂量效应模型,并对模型的有效性进行了验证。将辐照后器件等效为一个主晶体管与辐射导致的若干寄生晶体管并联,通过改变寄生晶体管的参数对辐照中的物理机制进行了模拟。对不同鳍片数量的内核(core)和输入输出(input output,IO)n-FinFET建立了能够描述器件在不同漏源电压下工作性能的模型,仿真结果与实验数据对比表明,所建立的模型的相对均方根偏差小于15%。

Radiative heat transfer analysis of a concave porous fin under the local thermal non-equilibrium condition:application of the clique polynomial method and physics-informed neural networks

The heat transfer through a concave permeable fin is analyzed by the local thermal non-equilibrium(LTNE)model.The governing dimensional temperature equations for the solid and fluid phases of the porous extended surface are modeled,and then are nondimensionalized by suitable dimensionless terms.Further,the obtained nondimensional equations are solved by the clique polynomial method(CPM).The effects of several dimensionless parameters on the fin's thermal profiles are shown by graphical illustrations.Additionally,the current study implements deep neural structures to solve physics-governed coupled equations,and the best-suited hyperparameters are attained by comparison with various network combinations.The results of the CPM and physicsinformed neural network(PINN)exhibit good agreement,signifying that both methods effectively solve the thermal modeling problem.

Tbx 4 and Tbx 5 gene expression associated with appendage development and its relationship with the absence of the pelvic fin in Pampus argenteus

The Tbx family is first known through the study of their functions in the body and limbs,and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages.Pampus argenteus is one of the important economical marine fishes widely distributed in offshore areas.Therefore,it is necessary to study the role of Tbx family genes in the deletion of pelvic fin in P.argenteus.In this study,we cloned Tbx4 and Tbx5 cDNA sequence of P.argenteus(GenBank:MH709128 and MH712458).The Western blot and real time PCR were used to detect the expressions of Tbx4 and Tbx5 in different developmental stages and tissues of P.argenteus.In addition,whole-mount in-situ hybridization was used to study the localization of Tbx4 and Tbx5 genes in different developmental stages of P.argenteus.Results show that the translation of Tbx4 mRNA was inhibited during the critical period of pelvic fin development.Among different tissues,Tbx4 protein levels were the lowest in the abdominal epithelium,and even lower than that in the pectoral fin,suggesting that the protein expression was also inhibited in the abdominal epithelium of adult P.argenteus.Therefore,the results indicated that upstream genes regulation led to the key stage-specific and low expression of Tbx4 during pelvic fin development and in the abdominal epithelium.

Transient Thermal Distribution in a Wavy Fin Using Finite Difference Approximation Based Physics Informed Neural Network

Heat transport has been significantly enhanced by the widespread usage of extended surfaces in various engi-neering domains.Gas turbine blade cooling,refrigeration,and electronic equipment cooling are a few prevalent applications.Thus,the thermal analysis of extended surfaces has been the subject of a significant assessment by researchers.Motivated by this,the present study describes the unsteady thermal dispersal phenomena in a wavy fin with the presence of convection heat transmission.This analysis also emphasizes a novel mathematical model in accordance with transient thermal change in a wavy profiled fin resulting from convection using the finite difference method(FDM)and physics informed neural network(PINN).The time and space-dependent governing partial differential equation(PDE)for the suggested heat problem has been translated into a dimensionless form using the relevant dimensionless terms.The graph depicts the effect of thermal parameters on the fin’s thermal profile.The temperature dispersion in the fin decreases as the dimensionless convection-conduction variable rises.The heat dispersion in the fin is decreased by increasing the aspect ratio,whereas the reverse behavior is seen with the time change.Furthermore,FDM-PINN results are validated against the outcomes of the FDM.

基于Fins/UDP通信协议的采煤机远程监控系统研究

为推进采煤机自动化水平的提升,研究了基于Fins/UDP通信协议的采煤机远程监控系统。详细阐述了Fins/UDP通信协议的报文构成,并构建了适用于煤矿井下采煤机的远程监控系统架构。借助开源的VUE和Flask框架,展开了系统软件的开发。最后,通过一系列实验,对系统的数据采集和指令下发等关键功能进行了验证。实验结果表明,所设计的系统可以实现对采煤机的有效远程监控。

Seismicity patterns before the 2021 Fin (Iran) doublet earthquakes using the region-time-length and time-to-failure methods

Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied. Furthermore, the estimation of the region-time-length (RTL) parameter has been proposed to detect seismic quiescence before the occurrence of a large earthquake. In addition, the time-to-failure method has been used to estimate the time occurrence of large earthquakes. Hence, in this study, to gain deeper insight into seismic activity in the southern Zagros region, we utilized the RTL algorithm to identify the quiescence and activation phases leading to the Fin doublet earthquakes. Temporal variations in the RTL parameter showed two significant anomalies. One corresponded to the occurrence time of the first earthquake (2017-12-12);the other anomaly was associated with the occurrence time of the second event (2021-11-14). Based on a negative value of the RTL parameter observed in the vicinity of the Fin epicenters (2021), seismic quiescence (a decrease in seismicity compared to the preceding background rate) was identified. The spatial distribution of the RTL prognostic parameters confirms the appearance of seismic quiescence surrounding the epicenter of the Fin doublet earthquakes (2021). The time-to-failure method was designed using precursory events that describe the acceleration of the seismic energy release before the mainshock. Using the time-to-failure method for the earthquake catalog, it was possible to estimate both the magnitude and time of failure of the Fin doublet. Hence, the time-tofailure technique can be a useful supplementary method to the RTL algorithm for determining the characteristics of impending earthquakes.

Heat dissipation enhancement method for finned heat sink for AGV motor driver's IGBT module

With the widespread use of high-power and highly integrated insulated gate bipolar transistor(IGBT),their cooling methods have become challenging.This paper proposes a liquid cooling scheme for heavy-duty automated guided vehicle(AGV)motor driver in port environment,and improves heat dissipation by analyzing and optimizing the core component of finned heat sink.Firstly,the temperature distribution of the initial scheme is studied by using Fluent software,and the heat transfer characteristics of the finned heat sink are obtained through numerical analysis.Secondly,an orthogonal test is designed and combined with the response surface methodology to optimize the structural parameters of the finned heat sink,resulting in a 14.57%increase in the heat dissipation effect.Finally,the effectiveness of heat dissipation enhancement is verified.This work provides valuable insights into improving the heat dissipation of IGBT modules and heat sinks,and provides guidance for their future applications.

探究复瑞彤联合胰岛素泵强化对改善2型糖尿病患者血糖、FINS、HOMA-IR的效果

目的:探究复瑞彤联合胰岛素泵强化治疗2型糖尿病的疗效及对血糖控制的效果。方法:回顾性选取医院2021年1月1日至2023年6月30日收治的88例2型糖尿病患者为研究对象,按不同方法分为对照组和观察组,各44例,对照组采用复瑞彤+安达唐,观察组采用复瑞彤+胰岛素泵强化治疗。比较两组治疗效果。结果:两组治疗前HbA1c、空腹血糖、餐后2h血糖无统计学差异(P>0.05);经治疗,观察组HbA1c(7.02±0.76)%、空腹血糖(5.19±0.27)mmol/L、餐后2h血糖(7.81±0.77)mmol/L均低于对照组(8.11±0.99)%、(5.49±0.26)mmol/L、(8.89±0.87)mmol/L(P<0.05)。两组治疗前FINS、HOMA-IR无统计学差异(P>0.05);经治疗,观察组FINS(11.33±0.94)mIU/L高于对照组(8.87±0.81)mIU/L,HOMA-IR(2.47±0.27)低于对照组(3.45±0.32)(P<0.05)。结论:对于2型糖尿病患者,在复瑞彤的基础上联合胰岛素泵强化治疗,可更好改善患者血糖。

基于FINS协议的计算机与PLC以太网通信

FINS协议用于OMRON的CompoBus/D、Controller Link、Ethernet等网络以及网络之间的通信。简要介绍了FINS协议,研究了基于FINS协议实现上位机和PLC以太网通信的方法。PLC选用OMRON CP1H型机,上位机采用Visual C++6.0编程,调用FINS指令向PLC发送命令,与PLC进行信息交换。给出部分程序代码。该方法可为进一步开发PLC监控系统提供了有价值的参考。

14 nm pFinFET 器件抗单粒子辐射的加固方法

为探究先进互补金属氧化物半导体(CMOS)工艺在空间应用中的可靠性问题,研究14 nm工艺下P型沟道鳍式场效应晶体管(pFinFET)器件中的抗单粒子瞬态(SET)加固策略。通过在器件中插入平行于鳍方向的重掺杂N型沟槽(Ntie)和P型沟槽(Ptie)来减缓SET的影响。三维TCAD仿真结果表明:加固之后器件的抗SET特性和沟槽本身的偏置条件相关。当重掺杂沟槽处于零偏状态时,抗辐射加固的性能最好,SET脉冲宽度降低程度可达40%左右;然而,当处于反偏状态时,由于特殊的电荷收集过程的存在,使得SET脉冲幅度反而会明显增大,脉冲宽度减小程度并不明显。此外,还研究沟槽面积、间距及掺杂浓度对pFinFET中的SET脉冲宽度的影响,得到提高抗SET效果的加固方法。

纳米FinFET的单粒子瞬态与Fin结构的相关性研究

工艺差异引起的Fin结构变化会造成纳米FinFET器件呈现不同的电学特性,使器件的单粒子瞬态效应(SET)复杂化。基于电学特性校准的14 nm SOI标准型FinFET器件,构建了弹头型、三角型、阶梯型、半圆型及底部椭圆型等5种结构,分析了SET的表征量与Fin结构参数间的相关性,并利用灰色理论,研究了它们之间的内在关联性。结果表明,器件的收集电荷量、沉积电荷量与Fin的截面积显著相关;SET电流峰值、电子-空穴对产生率峰值及双极放大系数同时依赖于Fin的截面积和等效沟道宽度,且对等效沟道宽度的依赖性更强。

Effect of periodic heat transfer on the transient thermal behavior of a convective-radiative fully wet porous moving trapezoidal fin

A moving trapezoidal profiled convective-radiative porous longitudinal fin wetted in a single-phase fluid is considered in the current article.The periodic variation in the fin base temperature is taken into account along with the temperature sensitive thermal conductivity and convective heat transfer coefficients.The modeled problem,which is resolved into a non-linear partial differential equation(PDE),is made dimensionless and solved by employing the finite difference method(FDM).The results are displayed through graphs and discussed.The effects of amplitude,frequency of oscillation,wet nature,Peclet number,and other relevant quantities on the distribution of temperature through the fin length and with the dimensionless time are investigated.It is deciphered that the periodic heat transfer gives rise to the wavy nature of the fin thermal profile against time.The analysis is beneficial in the design of fin structures for applications like solar collectors,space/airborne applications,and refrigeration industries.

基于拓扑优化的车用功率模块Pin-Fin设计方法

集成Pin-Fin散热器可以降低功率模块的结-流热阻,是车用电机控制器热管理的发展趋势。然而,传统参数设计方法无法定量表征Pin-Fin的形貌结构,设计自由度低、设计效果欠佳,难以实现Pin-Fin的热-流协同设计。基于变密度拓扑优化方法,该文提出一种Pin-Fin形貌结构的设计方法,建立Pin-Fin设计的变密度拓扑优化模型,分析模型参数对优化结果和收敛性的影响规律,形成以结-流热阻和冷却液压降为目标的协同优化方法,探索Pin-Fin结构的热-流耦合规律和强化换热方法,得到最优的Pin-Fin散热器形貌结构,搭建变流器实验平台和车用电机控制器样机,对标商业化圆形Pin-Fin结构,以及三角形、菱形和水滴形等其他形貌结构,计及母线电压、负荷电流和冷却液流量的影响,实验结果验证了所提模型方法的可行性和有效性。实验结果表明:基于拓扑优化方法设计的Pin-Fin结构,与传统结构相比可以降低12%的结-流热阻,消除了多芯片结温差异的80%,为车用功率模块和电机控制器研究提供新的思路。

Effect of temperature on heavy ion-induced single event transient on 16-nm FinFET inverter chains

The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.

Finned Zn-MFI zeolite encapsulated noble metal nanoparticle catalysts for the oxidative dehydrogenation of propane with carbon dioxide

Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existing catalyst is limited due to the poor activity and stability,which hinders its industrialization.Herein,we design the finned Zn-MFI zeolite encapsulated noble metal nanoparticles(NPs)as bifunctional catalysts(NPs@Zn-MFI)for CO_(2)-ODP.Characterization results reveal that the Zn2+species are coordinated with the MFI zeolite matrix as isolated cations and the NPs of Pt,Rh,or Rh Pt are highly dispersed in the zeolite crystals.The isolated Zn2+cations are very effective for activating the propane and the small NPs are favorable for activating the CO_(2),which synergistically promote the selective transformation of propane and CO_(2)to propylene and CO.As a result,the optimal 0.25%Rh0.50%Pt@Zn-MFI catalyst shows the best propylene yield,satisfactory CO_(2)conversion,and long-term stability.Moreover,considering the tunable synergetic effects between the isolated cations and NPs,the developed approach offers a general guideline to design more efficient CO_(2)-ODP catalysts,which is validated by the improved performance of the bifunctional catalysts via simply substituting Sn4+cations for Zn2+cations in the MFI zeolite matrix.

First Recorded Account of a White Shark Agonistic Pectoral Fin Depression Behavior at Guadalupe Island, Mexico

An agonistic display by a white shark was observed and photographed during a cage dive at Guadalupe Island in November 2015. Exhibiting exaggerated pectoral fin depression, agonistic behaviors have been previously observed and described in several shark species. This account may be the first record of a white shark in close proximity to a caged diver, exhibiting strong pectoral fin depression significantly dipped, in the mid-agonistic display. Such displays should be considered as aggressive and potentially life-threatening by those using the ocean for recreational or professional purposes.

FinFET芯片TEM样品制备及避免窗帘效应方法

制备高质量纳米尺度芯片透射电子显微镜(TEM)样品对于探索半导体器件结构设计、材料分布与芯片性能之间的关系具有重要的意义。使用聚焦离子束(FIB)/扫描电子显微镜(SEM)双束系统制备14 nm鳍式场效应晶体管(FinFET)截面TEM样品,制备过程中从技术角度提出了两种自下而上制样方案来抑制窗帘效应。为扩大样品的可表征视场范围,在避免样品弯曲的前提下,提出了一种薄片提取方法。结果表明,离子束流越大,窗帘效应越严重,自下而上方法能有效规避窗帘效应;离子束电压30 kV时采用清洗截面(CCS)模式、5 kV/2 kV时采用矩形模式,样品台倾斜补偿角度为1.5°~3.5°,进行交叉减薄,且最终铣削长度控制在1μm时减薄效果最好;新的薄片提取方法改变了样品的铣削方向,在避免窗帘效应破坏感兴趣结构和样品弯曲的前提下,将样品的可表征视场范围扩大了5倍。研究结果对优化TEM样品制备方法以及芯片失效分析提供了参考。

Localized Theoretical Analysis of Thermal Performance of Individually Finned Heat Pipe Heat Exchanger for Air Conditioning with Freon R404A as Working Fluid

This work contributes to the improvement of energy-saving in air conditioning systems. The objective is to apply the thermal efficiency of heat exchangers for localized determination of the thermal performance of heat exchangers with individually finned heat pipes. The fundamental parameters used for performance analysis were the number of fins per heat pipe, the number of heat pipes, the inlet temperatures, and the flow rates of hot and cold fluids. The heat exchanger under analysis uses Freon 404A as a working fluid in an air conditioning system for cooling in the Evaporator and energy recovery in the Condenser. The theoretical model is localized and applied individually to the Evaporator, Condenser, and heat exchanger regions. The results obtained through the simulation are compared with experimental results that use a global approach for the heat exchanger. The thermal quantities obtained through the theoretical model in the mentioned regions are air velocity, Nusselt number, thermal effectiveness, heat transfer rate, and outlet temperature. The comparisons made with global experimental results are in excellent agreement, demonstrating that the localized theoretical approach developed is consistent and can be used as a comprehensive analysis tool for heat exchangers using heat pipes.