Spintronic logic: from transducers to logic gates and circuits

While magnetic solid-state memory has found commercial applications to date, magnetic logic has rather remained on a conceptual level so far. Here, we discuss open challenges of different spintronic logic approaches, which use magnetic excitations for computation. While different logic gate designs have been proposed and proof of concept experiments have been reported, no nontrivial operational spintronic circuit has been demonstrated due to many open challenges in spintronic circuit and system design. Furthermore, the integration of spintronic circuits in CMOS systems will require the usage of transducers between the electric (CMOS) and magnetic domains. We show that these transducers can limit the performance as well as the energy consumption of hybrid CMOS-spintronic systems. Hence, the optimization of transducer efficiency will be a major step towards competitive spintronic logic system.Comment: This work has received funding from the European Union's Horizon 2020 research and innovation program within the project CHIRON (grant agreement no. 801055) as well as from the Horizon Europe research and innovation program within the project SPIDER (grant agreement no. 101070417

Analysis and implementation of an ultra-wide tuning range CMOS ring-VCO with inductor peaking

A novel ring voltage controlled oscillator (VCO) topology is proposed which uses monolithic inductors as a peaking load. Four design examples have been fabricated and tested to verify the proposed circuit structure. The highest measured oscillation frequency is 25.07 GHz, with a tuning range of more than four octaves, and the active area is 0.0085 mm². The design has the highest combined frequency and tuning range with the best figure of merit (~ 195) comparable to previously published work

Layer-by-layer growth of complex-shaped three-dimensional nanostructures with focused electron beams

The fabrication of three-dimensional (3D) nanostructures is of great interest to many areas of nanotechnology currently challenged by fundamental limitations of conventional lithography. One of the most promising direct-write methods for 3D nanofabrication is focused electron beam-induced deposition (FEBID), owing to its high spatial resolution and versatility. Here we extend FEBID to the growth of complex-shaped 3D nanostructures by combining the layer-by-layer approach of conventional macroscopic 3D printers and the proximity effect correction of electron beam lithography. This framework is based on the continuum FEBID model and is capable of adjusting for a wide range of effects present during deposition, including beam-induced heating, defocussing and gas flux anisotropies. We demonstrate the capabilities of our platform by fabricating free-standing nanowires, surfaces with varying curvatures and topologies, and general 3D objects, directly from standard stereolithography (STL) files and using different precursors. Real 3D nanoprinting as demonstrated here opens up exciting avenues for the study and exploitation of 3D nanoscale phenomena

Fabrication of a 3D Nanomagnetic Circuit with Multi-Layered Materials for Applications in Spintronics.

Three-dimensional (3D) spintronic devices are attracting significant research interest due to their potential for both fundamental studies and computing applications. However, their implementations face great challenges regarding not only the fabrication of 3D nanomagnets with high quality materials, but also their integration into 2D microelectronic circuits. In this study, we developed a new fabrication process to facilitate the efficient integration of both non-planar 3D geometries and high-quality multi-layered magnetic materials to prototype 3D spintronic devices, as a first step to investigate new physical effects in such systems. Specifically, we exploited 3D nanoprinting, physical vapour deposition and lithographic techniques to realise a 3D nanomagnetic circuit based on a nanobridge geometry, coated with high quality Ta/CoFeB/Ta layers. The successful establishment of this 3D circuit was verified through magnetotransport measurements in combination with micromagnetic simulations and finite element modelling. This fabrication process provides new capabilities for the realisation of a greater variety of 3D nanomagnetic circuits, which will facilitate the understanding and exploitation of 3D spintronic systems

Homocysteine Aggravates Intestinal Epithelial Barrier Dysfunction in Rats with Experimental Uremia

Background/Aims: Previous studies have shown that homocysteine (Hcy) is an important intestinal-derived uremic toxin. However, whether Hcy is involved in the epithelial barrier dysfunction observed in uremia remains unclear. This study aimed to investigate the effect of Hcy on intestinal permeability and intestinal barrier structure and function in adenine-induced uremic rats. Methods: Sprague-Dawley rats were divided into five groups: normal control (group NC), Hcy (group H), uremia (group U), uremia + Hcy (group UH), and uremia + Hcy + VSL#3 (group UHV). Experimental uremia was induced by intragastric adenine administration, and Hcy was injected subcutaneously. The animal models were assessed for renal function and pathological tissue staining. The pathological changes of intestinal tissue were observed by hematoxylin and eosin staining and electron microscopy. The serum and intestinal tissue levels of Hcy, interleukin (IL)-6, tumor necrosis factor (TNF)-α, superoxide dismutase (SOD), and malondialdehyde (MDA) as well as serum endotoxin and intestinal permeability were assessed. The levels of the tight junction proteins claudin-1, occludin, and zonula occludens-1 (ZO-1) were assessed by western blotting. Results: Blood analyses and renal pathology indicated that experimental uremia was induced successfully. Pathological damage to intestinal structure was most obvious in group UH. Serum and tissue Hcy, serum endotoxin, and intestinal permeability were significantly elevated in group UH. The protein levels of claudin-1, occludin, and ZO-1 were decreased to various degrees in group UH compared with groups NC, H, and U. The serum and tissue levels of IL-6, TNF-α, and MDA were significantly increased, while SOD activity was markedly decreased. Supplementation with the probiotic VSL#3 improved these parameters to various degrees and up-regulated the abundance of tight junction proteins, which indicated a role for Hcy in the increase of intestinal permeability and destruction of the epithelial barrier in uremia. Conclusion: Hcy aggravates the increase of intestinal permeability and destruction of the epithelial barrier by stimulating inflammatory and oxidative damage. Probiotic administration can ameliorate this damage by reducing the levels of Hcy-induced inflammation and oxidation

Non-Planar Geometrical Effects on the Magnetoelectrical Signal in a Three-Dimensional Nanomagnetic Circuit

Expanding nanomagnetism and spintronics into three dimensions (3D) offers great opportunities for both fundamental and technological studies. However, probing the influence of complex 3D geometries on magnetoelectrical phenomena poses important experimental and theoretical challenges. In this work, we investigate the magnetoelectrical signals of a ferromagnetic 3D nanodevice integrated into a microelectronic circuit using direct-write nanofabrication. Due to the 3D vectorial nature of both electrical current and magnetization, a complex superposition of several magnetoelectrical effects takes place. By performing electrical measurements under the application of 3D magnetic fields, in combination with macrospin simulations and finite element modelling, we disentangle the superimposed effects, finding how a 3D geometry leads to unusual angular dependences of well-known magnetotransport effects such as the anomalous Hall effect. Crucially, our analysis also reveals a strong role of the non-collinear demagnetizing fields intrinsic to 3D nanostructures, which results in an angular dependent magnon magnetoresistance contributing strongly to the total magnetoelectrical signal. These findings are key to the understanding of 3D spintronic systems and underpin further fundamental and device-based studies.Leverhulme Trust Isaac Newton Trust L’Oréal-UNESCO U.K. and Ireland Fellowship For Women In Science EPSRC Winton Program for Physics of Sustainability China Scholarship Council European Union’s Horizon 2020 research and innovation program Spanish AE

Integrated examination of the transcriptome and metabolome of the gene expression response and metabolite accumulation in soybean seeds for seed storability under aging stress

Soybean quality and production are determined by seed viability. A seed’s capacity to sustain germination via dry storage is known as its seed life. Thus, one of the main objectives for breeders is to preserve genetic variety and gather germplasm resources. However, seed quality and germplasm preservation have become significant obstacles. In this study, four artificially simulated aging treatment groups were set for 0, 24, 72, and 120 hours. Following an aging stress treatment, the transcriptome and metabolome data were compared in two soybean lines with notable differences in seed vigor—R31 (aging sensitive) and R80 (aging tolerant). The results showed that 83 (38 upregulated and 45 downregulated), 30 (19 upregulated and 11 downregulated), 90 (52 upregulated and 38 downregulated), and 54 (25 upregulated and 29 downregulated) DEGs were differentially expressed, respectively. A total of 62 (29 upregulated and 33 downregulated), 94 (49 upregulated and 45 downregulated), 91 (53 upregulated and 38 downregulated), and 135 (111 upregulated and 24 downregulated) differential metabolites accumulated. Combining the results of transcriptome and metabolome investigations demonstrated that the difference between R31 and R80 responses to aging stress was caused by genes related to phenylpropanoid metabolism pathway, which is linked to the seed metabolite caffeic acid. According to this study’s preliminary findings, the aging-resistant line accumulated more caffeic acid than the aging-sensitive line, which improved its capacity to block lipoxygenase (LOX) activity. An enzyme activity inhibition test was used to demonstrate the effect of caffeic acid. After soaking seeds in 1 mM caffeic acid (a LOX inhibitor) for 6 hours and artificially aging them for 24 hours, the germination rates of the R31 and R80 seeds were enhanced. In conclusion, caffeic acid has been shown to partially mitigate the negative effects of soybean seed aging stress and to improve seed vitality. This finding should serve as a theoretical foundation for future research on the aging mechanism of soybean seeds

Complex free-space magnetic field textures induced by three-dimensional magnetic nanostructures.

The design of complex, competing effects in magnetic systems-be it via the introduction of nonlinear interactions1-4, or the patterning of three-dimensional geometries5,6-is an emerging route to achieve new functionalities. In particular, through the design of three-dimensional geometries and curvature, intrastructure properties such as anisotropy and chirality, both geometry-induced and intrinsic, can be directly controlled, leading to a host of new physics and functionalities, such as three-dimensional chiral spin states7, ultrafast chiral domain wall dynamics8-10 and spin textures with new spin topologies7,11. Here, we advance beyond the control of intrastructure properties in three dimensions and tailor the magnetostatic coupling of neighbouring magnetic structures, an interstructure property that allows us to generate complex textures in the magnetic stray field. For this, we harness direct write nanofabrication techniques, creating intertwined nanomagnetic cobalt double helices, where curvature, torsion, chirality and magnetic coupling are jointly exploited. By reconstructing the three-dimensional vectorial magnetic state of the double helices with soft-X-ray magnetic laminography12,13, we identify the presence of a regular array of highly coupled locked domain wall pairs in neighbouring helices. Micromagnetic simulations reveal that the magnetization configuration leads to the formation of an array of complex textures in the magnetic induction, consisting of vortices in the magnetization and antivortices in free space, which together form an effective B field cross-tie wall14. The design and creation of complex three-dimensional magnetic field nanotextures opens new possibilities for smart materials15, unconventional computing2,16, particle trapping17,18 and magnetic imaging19.EPSRC Early Career Fellowship EP/M008517/1 Winton Program for the Physics of Sustainability Leverhulme Trust (ECF-2018-016) Isaac Newton Trust (18-08) L’Oréal-UNESCO UK and Ireland Fellowship For Women In Science 2019 European Union’s Horizon 2020 research and innovation program under Marie Skłodowska-Curie grant ref. H2020-MSCA-IF-2016-746958 Spanish AEI under project reference PID2019–104604RB/AEI/10.13039/501100011033 German Ministerium für Bildung und Forschung (BMBF) through contracts 05K16WED and 05K19WE2 European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 701647 FWF project I 4917

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216