水杨醛缩－5－碘－8－氨基喹啉新西夫碱试剂的合成及其分析应用研究──分光光度法测定痕量镓

本文介绍了水杨醛缩－５－碘－８－氨基喹啉新西夫碱的合成、提纯与鉴定。特别对其性质及其与镓金属离子显色反应的光度特性作了研究，其配合物３．４９×１０４Ｌ·ｍｏｌ（－１）·ｃｍ（－１）．     

Microstructure evolution of a hypereutectic Nb–Ti–Si–Cr–Al–Hf alloy processed by directional solidification

In this work, the Nb–14Si–24Ti–10Cr–2Al–2Hf–0.1Y alloy(at.%) was processed by the liquid–metal-cooled directional solidification(DS) at 1750 C with withdrawal rates of 1.2, 6,18 mm/min and post heat treatment(HT) at 1450 C for 10 h. The microstructures of the directionally solidified and heat treated samples were investigated. The results show that the microstructure of directionally solidified alloy mainly consists of petaloid Nbss+ Nb5Si3eutectics and Ti-rich Nbss+ Nb5Si3+ Cr2Nb eutectics. With the increase of withdrawal rate, the primary Nb5Si3is eliminated, Nbss+ Nb5Si3eutectic cells turn round and connected with the microstructure refinement and Nbss+ Nb5Si3+ Cr2Nb eutectics turn to a river-like morphology. After heat treatment,Nbss+ Nb5Si3+ Cr2Nb eutectics disappeared and petaloid Nbss+ Nb5Si3eutectics turn to a specific fiber-mesh structure gradually, which is promoted by higher withdrawal rates. Furthermore,both the volume fraction of Cr2Nb and the content of Cr in Nbssof Nbss+ Nb5Si3eutectics change regularly with the increase of withdrawal rate and heat treatment at 1450 C for 10 h.     

H-450 X射线参考辐射质的研建及验证

根据PTB和ISO 4037-1:2019要求,关于高空气比释动能系列（H系列）X射线参考辐射质的推荐数据,外推得出H-450的附加过滤为6.24 mm Cu,第一半值层（HVL_1st）为(5.39~5.52)mm Cu,平均光子能量为(214.25~214.78)keV,剂量率为11.51 Gy/h（距离焦斑为1 m处,管电流为10 mA）。随后,使用PTW32005电离室作为测量器具,采用半值层法建立H-450 X射线参考辐射质,得出HVL_1st为5.37 mm Cu,第二半值层（HVL_2nd）为5.97 mm Cu,同质系数为0.9。最后,使用PTW30013次级标准电离室测量得出H-450 X射线参考辐射质下距离焦斑1 m,管电流为10 mA时的剂量率值为11.98 Gy/h,与理论值的相对误差为4.07 %。采用MCNP 5软件对H-450 X射线参考辐射质进行能谱模拟并计算得出其平均光子能量为200.4 keV。     

热开关热管在月面探测光学设备中的应用

在月面-180~+90℃的极端高低温环境下,月面探测光学设备的月昼远距离散热和月夜保温矛盾异常突出。针对设备热耗的传输、排散,以及月夜生存时的热能存留问题,利用热管工质的汽、液、固相变特性,提出一种无源热开关热管作为设备和散热面间长距离传热手段,即依据设备温度指标选择具有合适凝固点和传热能力的工质,当月昼工作期间通过热管内工质两相传热实现热量的高效收集和传输,到月夜期间冻结热管内全部工质,完全切断热管与散热面间的两相传热,维持设备温度。地面试验和在轨飞行数据表明,热开关热管凝固点附近热导比达30以上。热管工作时,7℃时传热能力大于15W,传热温差小于4℃,且能够适应着陆器±15°的倾斜,确保了嫦娥三号着陆器月基光学望远镜在轨的高性能工作。     

基于5G的通导融合位置认证系统性能分析

随着无人化智能移动装备在工业、交通等安全敏感领域的普及应用，民用导航定位系统中的定位安全问题日益突出。位置认证是对终端的物理位置声明进行认证的过程，是导航定位安全技术的重要组成部分。基于第五代(5G)移动通信网络的通导融合位置认证系统具有覆盖范围广、认证精度高、用户容量大、建设运维成本低等多重优势。本文首先介绍了多基站位置认证系统的检测判决原理，提出了漏检平均距离的定义作为位置认证系统精度的量化评价指标。在此基础上，通过数值仿真分析了信号带宽、基站同步误差、信噪比对位置认证系统精度的影响，并利用5G信道模型评估了典型场景下的位置认证系统的性能。结果表明，在具备3个以上的视距基站时，基于5G的通导融合位置认证系统可以实现米级的位置认证精度。     

Comparison Structure Forms Between Isogrid and Orthogrid of C/ E CompositeTrellis Wound Structure Based on Calculation of Load Carrying

This paper calculated load carrying of isogrid and orthogrid of carbon epoxy composite trellis wound
structure (C/ E CTWS) using non linear finite element method. Based on the analysis, test cases were designed and
tests of axial compression were carried. Analysis result and test result fit well. In order to be used in the project, this
kind of structure cut out repairing was calculated. The method presented in this paper has been proved and can be used
to solve complicated engineering problems. According to calculations and experimental results combined with applica
tion, a principle of choosing wound structure is obtained and principle could be applied to engineering.
     

Analysis of Chang’e-5 lunar core drilling process

Chang’e-5 explorer successfully acquired lunar regolith core samples from depths of greater than 1 m of lunar surface. This study analyzed the lunar core drilling process based on the telemetry data, image information, and returned samples to optimize the sampling device design and enhance the understanding of the lunar regolith. In particular, a prediction method for the projected drilling path and local terrain fitting of drilling dip angle was proposed based on the flight events recorded during the core drilling process and the image information acquired before, during, and after sampling. The results revealed that the drilling dip angle of Chang’e-5 was approximately 2.3°, and the deviation of the drilling length and depth was less than 2 mm. For continuous drilling, a fusion method based on telemetry data and image information was applied to determine the demarcation point of drilling with and without the lunar soil. The position of the demarcation point implied that the drilling point remained at approximately 6 mm loose soil, thereby lagging the action of the force response. Additionally, a characteristic parameter comparison method was proposed for the lunar and ground drilling to analyze the status of the lunar soil. Furthermore, the analysis results revealed that the majority of the Chang’e-5 drilling samples were derived from 0–73.8 cm below the lunar surface and few samples were extracted below 73.8 cm, as the drilling encountered several rocky regions. Moreover, the drilling point exhibited two prominent stratification variations at ～28.7 cm and ～70 cm below the lunar surface. Ultimately, the preliminary relationship between sample dissected position in soft tube and drilling displacement was analyzed. The segmented estimation results can support research on subsurface lunar soil.     

无强波构型理论发展现状研究

本文引入了一种由Busemann超声速双翼理论发展而来的无强激波构型,该构型可明显消弱超声速飞行时带来的波阻和声爆。文中分析了无强波构型的机理和气动特性,介绍了该构型理论研究和应用研究进展,并探讨了该构型在超声速飞行器设计应用中的关键性问题。该理论为未来低声爆超声速飞机的设计提供了一个全新的思路,是未来超声速/高超声速飞行器发展必要的技术基础。     

Effect of the continental shelf in seasonal oceanographic conditions at the Northern edge of the Eastern Tropical Pacific

The continental shelf in front of Nayarit is located in the northern limit of the tropical Eastern Pacific, characterized by constituting a convergence zone of different masses of water, forming an area of significant hydrographic variability. Based on satellite remote sensing data and reanalysis between 2003 and 2019 of sea surface temperature (SST), wind stress, Ekman velocity, and geostrophic velocity, the contribution of the seasonal cycle to the variability of the study area were analyzed through climatological means, Hovmöhler diagrams, and Empirical Orthogonal Functions. The results show that in the zone in front of Matanchén Bay (21.5 °N) and the adjacent continental shelf, there is a core of warm surface water. The distribution of the SST is explained by the seasonal pattern of meridional/zonal variability in the thermal gradient, where the EOFs show the influence of the annual scale in both modes, with the only difference being that the first describes the meridional gradient as the dominant signal (66.2%), and the second shows the zonal behavior of the thermal gradient (16.6%). The summer weakening of the wind stress and Ekman speed is the product of the irregular shape of the coastline, the extension of the continental shelf, and the divergence of the North American monsoon around 21°N, whereas during the rest of the year an intensification of these parameters prevailed in front of Cabo Corrientes. On the other hand, the intense geostrophic flow in summer does not contribute to the increase in SST on the continental shelf because it diverges around 22.5°N. Likewise, during the winter, the formation of a cyclonic geostrophic gyre located inside the continental shelf, between the coast and the Marías Islands, stands out.     

Gas-dynamic approach to the theory of non-linear ion-acoustic waves in plasma with Kaniadakis’ distributed species

The non-linear theory of ion-acoustic waves in two-spesies isotropic collisionless plasma is developed. Both light electron and heavy ion species in the plasma are distributed with Kaniadakis’ statistics. Kaniadakis’ gas law is derived. The exact formula for the Sagdeev pseudopotential in parametric form is derived by the method based on the integration of the inverse function. The pseudopotential is analyzed. It is shown that periodic ion-acoustic waves and solitons are possible in the studied plasma. The differential equation describing the profile of the ion concentration in the wave is derived. The profiles of this concentration in the periodic ion-acoustic wave and soliton are calculated.