摘要：提出了一种基于二代镍基单晶(SX)高温合金γ′相尺寸变化统计分析的SX高温合金固溶热处理最佳时间的选择方法。通过数值分析引入了微观结构均匀性ω,根据数据统计ω曲线可分为3个阶段:显著变化区、过渡区和稳态区。过渡区描述了固溶热处理时间选择的最佳范围。通过测量合金的γ′筏化和蠕变性能,验证了该方法的有效性。同时也通过第四代镍基SX高温合金验证了该方法的准确性。该方法能够有效地建立最优的热处理工艺,并为SX高温合金的设计和工程应用提供指导。

摘要：析氧反应的高反应势垒一直是水分解反应的瓶颈,目前迫切需要低成本、高性能且稳定的催化剂.本文采用共掺杂策略设计了一种有效的析氧反应电催化剂BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ).当电流密度在10 mA/cm^(2)时,BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)的过电位为310 mV,Tafel斜率为50.2 mV/***_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)的催化性能比Fe掺杂的BaCo_(0.8)Fe_(0.2)O_(3−δ)(BCF 360 mV)、Ni掺杂的BaCo_(0.8)Ni_(0.2)O_(3−δ)(375 mV)和IrO_(2)(329 mV)要好得多同时,BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)也是一种比较稳定的碱性析氧反应催化剂.经过500次循环扫描,BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)仍然表现出良好的催化活性,催化性能没有明显下降.电化学实验表明,BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)在本文研究的材料中具有最快的反应动力学特征和最低的电荷转移电阻.此外,BaCo_(0.6)Fe_(0.2)Ni_(0.2)O_(3−δ)表面大量的高氧活性物种O_(2)^(2-)/O^(-)和羟基OH^(-)物种有利于析氧反应的发生,从而提高了反应速率.该研究为高性能电催化剂的开发提供了一种通用策略.

摘要：The human gut is a complex ecosystem,inhabited by a diverse range of microorganisms,including bacteria,archaea,fungi,as well as viruses,collectively known as the gut *** microorganisms interact with each other and also with the host,performing multifaceted functions that support the host’s vital life activities[1].The gut microbiota exerts significant influence on numerous physiological processes in the host,including metabolism,immunomodulation,and regulation of nervous system[2,3].research conducted over the past few decades has demonstrated the importance of maintaining a balanced intestinal microbiota for human *** of gut microbiota is usually associated with a variety of diseases,such as inflammatory bowel disease(IBd),obesity,diabetes,colorectal cancer,and cardiovascular,as well as neurological and psychiatric disorders,such as anxiety,depression,autism,and Parkinson’s disease[2,4].As our understanding of the gut microbiota continues to improve,conventional gut microbiota-targeted interventions or utilizing engineered bacteria as therapeutic carriers hold great promise in the treatment or alleviation of various intestinal and systemic diseases.

摘要：利用InP基共振隧穿二极管(rTd)和加载硅透镜的片上天线设计实现了超过1 THz的振荡器。采用Silvaco软件对rTd模型进行仿真研究,分析了不同发射区掺杂浓度、势垒层厚度、隔离层厚度以及势阱层厚度等对器件直流特性的影响规律。对研制的rTd器件直流特性测试显示:峰值电流密度J_(p)为359.2 kA/cm^(2),谷值电流密度J_(v)为135.8 kA/cm^(2),峰谷电流比PVCr为2.64,理论计算得到的器件最大射频输出功率和振荡频率(f_(max))分别为1.71 mW和1.49 THz。利用透镜封装的形式对采用Bow-tie片上天线和rTd设计的太赫兹振荡器进行封装,测试得到振荡频率超过1 THz,输出功率为2.57μW,直流功耗为8.33 mW,是国内首次报道超过1 THz的振荡器。

摘要：随着穿越活断层隧道工程建设的飞速发展,跨断层隧道的分析和设计方法迫切需要相应的理论指导。本研究通过振动台模型试验和数值模拟,探讨了断层位错和地面运动对不同长度管片衬砌结构的影响规律和破坏机制。结果表明,随着衬砌纵向连接刚度(节理和节段衬砌)的减小,上盘与断裂带之间的结构相对位移减小,而下盘与断裂带之间的结构相对位移变化趋势相反。因此,应根据工程要求将靠近上盘的衬砌段划分为较小的段,而靠近下盘的衬砌段应划分为较大的段。结合试验结果提出了断层附近影响带的设防范围。在划分分段长度时还应考虑衬砌接缝的作用,以便在断层位错的影响下实现纵线的平滑过渡。本文数值模拟的破坏演化过程与振动台试验结果吻合较好。

摘要：复杂的超导量子电路可以用来设计对噪声免疫的量子比特,但其复杂性可能会超出经典计算机所具备的模拟能力.在这种情况下,可以借助量子计算机来对其进行高效的模拟.在这项工作中,作者展示了在基于transmon比特的量子计算机上,利用变分量子算法模拟一种超导量子电路,并且基于此设计了一种新的量子比特“Plasmonium”,它工作在等离子体跃迁区域.文中展示的Plasmonium量子比特展示出了较高的两比特门保真度99.58(3)%.相比于transmon比特,它具有更小的物理尺寸和更大的非谐性.这些特征使得Plasmonium可以成为制造多比特量子处理器强有力的候选者.这项研究结果证实了利用量子计算机辅助设计更先进的量子处理器的可能性.

摘要：Introduction despite the numerous breakthroughs made in medical and biomedical technologies,biosensing underneath the skin without any associated pain still sounds like a dream yet to be *** invasive biosensors refer to functional or electronic sensors that can contact the interior environment of living organisms and their biological tissues,while the connected bulk devices remain on the surface of the biological objects[1].Minimally invasive biosensors are currently a key research area because they can not only meet the increasing technical demands to precisely detect biological activities inside biological objects,but also provide an ideal platform to externally incorporate complicated functionalities and electronic integration[2].The current development level of minimally invasive sensing still necessitates solving the constraints and bottlenecks in the three aspects of functionalities,sensitivity and biocompatibility[3].In this perspective,we select minimally invasive sensors as a representative research object with the aim to solve the limitations of current diabetes diagnosis and treatment approaches.

摘要：With more large-scale scientific computing tasks being delivered to cloud computing platforms, cloud workflow systems are designed for managing and arranging these complicated tasks. However, multi-tenant coexistence service mode of cloud computing brings serious security risks, which will threaten the normal execution of cloud workflows. To strengthen the security of cloud workflows, a mimic cloud computing task execution system for scientific workflows is proposed. The idea of mimic defense contains mainly three aspects: heterogeneity, redundancy, and dynamics. For heterogeneity, the diversities of physical servers, hypervisors, and operating systems are integrated to build a robust system framework. For redundancy, each sub-task of the workflow will be executed simultaneously by multiple executors. Considering efficiency and security, a delayed decision mechanism is proposed to check the results of task execution. For dynamics, a dynamic task scheduling mechanism is devised for switching workflow execution environment and shortening the life cycle of executors, which can confuse the adversaries and purify task executors. Experimental results show that the proposed system can effectively strengthen the security of cloud workflow execution.

摘要：在列车撞击动力学中,简化的刚体模型被广泛应用于研究列车耐撞性,以及进一步优化列车在冲击载荷下的能量分布。然而忽略弹性波传播对列车耐撞性能的影响尚不清楚。为了解决这一问题,本文建立了简化的一维弹性车体模型,并研究了弹性波传播对列车能量耗散以及动力学特性的影响。基于经典的弹性波传播理论,提出了一种密度及弹性模量缩比准则,使一维弹性车体的运动特性与其横截面积无关。讨论了弹性波传播速度对不同冲击速度下三节编组列车在冲击工况下的能量吸收、弹性能储存以及车体最终的等效平衡速度的影响。研究发现,当弹性波的传播速度约为3500 m/s时,一维弹性车体与实际列车模型的一致性最好。在初始冲击速度为10、15和20 m/s时,简化的一维弹性模型吸能量与实际列车模型相比误差仅为2.56%、1.84%和1.45%,而简化的刚性模型能量吸收量比实际列车模型高10.7%、12.4%和14.8%,刚性模型显著高估了列车的能量吸收量。我们的研究结果可以促进列车在碰撞条件下的耐撞性设计和优化。

摘要：电磁场及流体演化过程信息的获取在高能量密度物理、可控核聚变及实验天体物理的研究中起着重要的作用,然而在实验过程中,电磁场信息及流体信息的同步获取是非常困难的。基于高能电子透镜成像技术,利用面密度差分的方法,提出了一种可以实现面密度和场积分强度同时获取的双自由度诊断设计方案。结合了蒙特卡罗模拟和束流光学分析,该方案在相对较强的电磁场情况下的适用性得到了验证。此外,我们可以通过改变Fourier面处光阑的形状将其适用区间扩展到低电磁场强度相空间。结合高能电子束相对论速度及超短脉冲的特点,该技术非常适用于磁流体超快演化过程的诊断。