摘要：共晶高熵合金因其所展现出的特殊物理/化学性能而受到材料界的广泛关注.然而,除了FCC+B2系外,其他大部分所报道的共晶高熵合金系均呈现为固有脆性,这使得它们逐渐失去了工业应用的竞争优势.本工作提出了一种新的协同改善脆性CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金强韧性的球化+再结晶工艺.基于该工艺,CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金获得了一种精心设计的球状M3B2镶嵌在细小FCC晶界处的微观结构,使其抗拉强度、屈服强度和延伸率从923 MPa/620 MPa/1.3%提高到1326-1530 MPa/990-1330 MPa/8.4%-13.9%,提高了43.7%-65.8%/59.7%-114.5%/546%-9.69%.强塑化机制主要归因于球化和再结晶微观结构提供了更多的界面阻碍位错移动和促进了更加均匀的应力分布.该工作为协同改善脆性共晶高熵合金强韧性以满足工程安全性需求提供了新的思路.

摘要：Hall thruster is a type of electric propulsion thruster which is often regarded as a moderate specific im- pulse space propulsion technology and is used primarily for station keeping and orbit maintenance tasks. Magnetic field is the most important aspect in Hall thruster＇s design. Each time the performance improvement of Hall thrusters is accompanied with the regeneration of magnetic field design. Now, all the maior space nations treat the magnetic field design as the key technology for Hall thrusters, and many Hall thrusters have emerged in recent years, for example, BPT-4000 and NASA- 173M. In China, based on magnetic focus technology, the beijing institute of control Engineer- ing （BICE） has been developing Hall thrusters ranged from hundreds of watts to 5 kilowatts, including the IS00 W HEP- 100MF and the 5 kW HEP- 140blF Hall thrusters. This paper briefly reviews the development of the HEP-XXMF series Hall thruster. The principle of the Hall thruster, the design methods and the current status of HEP-100MF and HEP- 140MF are discussed in the paper.

摘要：The determination of carbon emission from foundation pit engineering is a tough and complex project owing to its characteristics including large material consumption,short use time,difficult recycling and no operation *** overcome these limitations,the calculation boundary and calculation method for carbon emission of foundation pit project are defined in this paper,which is successfully applied in the carbon emission analysis of the actual engineering project,*** construction of large-scale foundation pit of Kunming comprehensive transportation international *** the carbon emissions coresponding to four working stages including building materials production,building materials transportation,construction and demolition were calculated and *** results revealed that the content of CO_(2) released in the stage of building materials production accounts for 89.3%of the total carbon emission,which means the amount of building materials consumed in the engineering project is the crucial factor to control the carbon ***,two kinds of carbon reduction measures,*** design of support scheme and recycling waste materials of internal support demolition,were explored by analyzing the proportion and average value of carbon emission from different sub project of the support structure.A pronounced effect of carbon reduction was ***,both a fast calculation method of carbon emission factor of unit work volume and general carbon reduction measures are proposed in this paper,which could provide a reference and new viewpoint for the engineers and designers to calculate and analyze the carbon emission and to take effective carbon reduction measures.

摘要：本文介绍了一种基于横向可移动栅极场效应晶体管(LMGFET)的新型微型力传感器的开发。提出了一种精确的电气模型,用于小型LMGFET器件的性能评估,与以前的模型相比,其精度有所提高。采用了一种新型三明治结构,该结构由一个金交叉解耦栅阵列层和两个软光阻层SU-8组成。通过所提出的双差分传感结构,LMGFET横向工作在垂直干扰下的输出电流被大大消除,所提出传感器的相对输出误差从4.53%(传统差分结构)降低到0.01%。提出了一种实用的传感器制造工艺,并对其进行了模拟。基于LMGFET的力传感器的灵敏度为4.65μA·nN^(-1),可与垂直可移动栅极场效应晶体管(VMGFET)器件相媲美,但非线性度提高了0.78%,测量范围扩大了±5.10μN。这些分析为LMGFET器件的电气和结构参数提供了全面的设计优化,并证明了所提出的传感器在生物医学显微操作应用中具有良好的力传感潜力。

摘要：The thermal conduction of suspended few-layer hexagonal boron nitride （h-BN） sheets was experimentally investigated using a noncontact micro-Raman spectroscopy method. The first-order temperature coefficients for monolayer （1L）, bilayer （2L） and nine-layer （9L） h-BN sheets were measured to be -（3.41 ± 0.12）× 10-2, -（3.15 ± 0.14） × 10-2 and -（3.78 ±0.16）× 10-2 cm-1.K-1, respectively. The room-temperature thermal conductivity of few-layer h-BN sheets was found to be in the range from 227 to 280 W.m-1-K-1, which is comparable to that of bulk h-BN, indicating their potential use as important components to solve heat dissipation problems in thermal management configurations.