12 research outputs found
Identifi cation and characterization of components
In the information age, components in all kinds of electronic products occupy an important position, in particular, somecommon electronic components, electronic products is essential to the basic material. The performance of various typesof components, features, the use of the scope of the function of the electronic product design and manufacturing hasa very important role especially in the past period. Along with the rapid development of the electronics industry, newrequirements and components industry is also constantly using new materials. New technology has introduced newproducts for the development of electronic products to open up new ways. This chapter will be a number of commonlyused electronic components according to its type, performance characteristics and testing. As a brief introduction andstrive to have a wide range of components have a general understanding in order to facilitate product design and expandthe range of components used
Satellite-MEC Integration for 6G Internet of Things: Minimal Structures, Advances, and Prospects
The sixth-generation (6G) network is envisioned to shift its focus from the
service requirements of human beings' to those of Internet-of-Things (IoT)
devices'. Satellite communications are indispensable in 6G to support IoT
devices operating in rural or disastrous areas. However, satellite networks
face the inherent challenges of low data rate and large latency, which may not
support computation-intensive and delay-sensitive IoT applications. Mobile Edge
Computing (MEC) is a burgeoning paradigm by extending cloud computing
capabilities to the network edge. By utilizing MEC technologies, the
resource-limited IoT devices can access abundant computation resources with low
latency, which enables the highly demanding applications while meeting strict
delay requirements. Therefore, an integration of satellite communications and
MEC technologies is necessary to better enable 6G IoT. In this survey, we
provide a holistic overview of satellite-MEC integration. We first discuss the
main challenges of the integrated satellite-MEC network and propose three
minimal integrating structures. For each minimal structure, we summarize the
current advances in terms of their research topics, after which we discuss the
lessons learned and future directions of the minimal structure. Finally, we
outline potential research issues to envision a more intelligent, more secure,
and greener integrated satellite-MEC network
Integrating Satellites and Mobile Edge Computing for 6G Wide-Area Edge Intelligence: Minimal Structures and Systematic Thinking
The sixth-generation (6G) network will shift its focus to supporting everything including various machine-type devices (MTDs) in an every-one-centric manner. To ubiquitously cover the MTDs working in rural and disastrous areas, satellite communications become indispensable, while mobile edge computing (MEC) also plays an increasingly crucial role. Their sophisticated integration enables wide-area edge intelligence which promises to facilitate globally-distributed customized services. In this article, we present typical use cases of integrated satellite-MEC networks and discuss the main challenges therein. Inspired by the protein structure and the systematic engineering methodology, we propose three minimal integrating structures, based on which a complex integrated satellite-MEC network can be treated as their extension and combination. We discuss the unique characteristics and key problems of each minimal structure. Accordingly, we establish an on-demand network orchestration framework to enrich the hierarchy of network management, which further leads to a process-oriented network optimization method. On that basis, a case study is utilized to showcase the benefits of on-demand network orchestration and process-oriented network optimization. Finally, we outline potential research issues to envision a more intelligent, more secure, and greener integrated network
Tightly-bound and room-temperature-stable excitons in van der Waals degenerate-semiconductor Bi4O4SeCl2 with high charge-carrier density
Excitons, which represent a type of quasi-particles consisting of
electron-hole pairs bound by the mutual Coulomb interaction, were often
observed in lowly-doped semiconductors or insulators. However, realizing
excitons in the semiconductors or insulators with high charge carrier densities
is a challenging task. Here, we perform infrared spectroscopy, electrical
transport, ab initio calculation, and angle-resolved-photoemission spectroscopy
studies of a van der Waals degenerate-semiconductor Bi4O4SeCl2. A peak-like
feature (i.e., alpha peak) is present around ~ 125 meV in the optical
conductivity spectra at low temperature T = 8 K and room temperature. After
being excluded from the optical excitations of free carriers, interband
transitions, localized states and polarons, the alpha peak is assigned as the
exciton absorption. Moreover, assuming the existence of weakly-bound
excitons--Wannier-type excitons in this material violates the
Lyddane-Sachs-Teller relation. Besides, the exciton binding energy of ~ 375
meV, which is about an order of magnitude larger than those of conventional
semiconductors, and the charge-carrier concentration of ~ 1.25 * 10^19 cm^-3,
which is higher than the Mott density, further indicate that the excitons in
this highly-doped system should be tightly bound. Our results pave the way for
developing the optoelectronic devices based on the tightly-bound and
room-temperature-stable excitons in highly-doped van der Waals degenerate
semiconductors.Comment: Accepted by Communications Material
Experimental Studies on Breakup and Fragmentation Behavior of Molten Tin and Coolant Interaction
Jet breakup and fragmentation behavior significantly affect the likelihood (and ultimate strength) of steam explosion, but it is very challenging to assess the potential damage to reactor cavity due to general lack of knowledge regarding jet breakup phenomena. In this study, the METRIC (mechanism study test apparatus for melt-coolant interaction) was launched at Shanghai Jiao Tong University to investigate FCI physics. The first five tests on molten tin and water interactions are analyzed in this paper. Significant breakup and fragmentation were observed without considerable pressure pulse, and intense expansion of droplets in local areas was observed at melt temperature higher than 600°C. The chain interactions of expansion all ceased, however, and there was no energetic steam explosion observed. Quantitative analysis on jet breakup length and debris was studied to investigate the effect of the melt temperature, initial diameter of the jet, and so on. Furthermore, the results of tests were compared with current theories. It is found that melt temperature has strong impact on fragmentation that need to be embodied in advanced fragmentation models
Long-term follow-up of methimazole-associated insulin autoimmune syndrome: a rare case report
Insulin autoimmune syndrome (IAS) is a rare cause of hypoglycemia and is characterized by the presence of insulin autoantibodies and fasting or late postprandial hypoglycemia. The number of reports on the association of long-term follow-up of IAS in China is limited. We herein report a case of drug-induced IAS in a 44-year-old Chinese woman. She had been taking methimazole for Graves’ disease and had subsequently presented with recurrent hypoglycemic episodes. Laboratory assessments on admission revealed that her serum insulin level was significantly elevated (>1000 µIU/mL) and that she was positive for serum insulin autoantibody, leading to a diagnosis of IAS. Human leukocyte antigen DNA typing identified *04:06/*09:01:02, an immunogenetic determinant associated with IAS. After treatment with prednisone for 2 months, the hypoglycemic episodes disappeared, her serum insulin level gradually declined, and her insulin antibody levels became negative. Clinicians should be aware of the potential for methimazole to trigger autoimmune hypoglycemia in people with a genetic predisposition