Spin-and Valley-Dependent Transport in Hybrid System and 2D Dirac Materials.

151 p.In this thesis, we aim to study the spin- and valley-dependent transport in hybrid system and twodimensionalDirac materials.In the first part, I study some spin-dependent and phase-coherent phenomena in hybrid structures.First, I present a full microscopic theory of the spin Hall magnetoresistance (SMR) in non-magneticmetal/magnetic insulator heterostructures. As examples, we apply it into both paramagnetic andferromagnetic SMR, specifically Platinum/Gd3Ga5O12 (Pt/GGG) and Platinum/Europium sulfide(Pt/EuS), respectively. Furthermore, if non-magnetic metal is replaced by nanowire in proximity tosuperconductor below the critical temperature, we can study the interplay of magnetic andsuperconducting proximity effects.In the second part, I explore the possible mechanisms responsible for the classical versions of spinand valley Hall effects, and proposed the schemes for experimental detection of these effects bynonlocal resistance measurements. The understanding of the magnetic properties of nonlocalresistance is significant for the recent controversy about the physical origin of nonlocal resistancemeasured in Hall bar devices made of graphene decorated with absorbates, where the presence oflarge nonlocal resistance and the absence of Hanle oscillation, that is, an oscillation of the nonlocalresistance with in-plane magnetic field, suggest the possibility of the new origin of nonlocalresistance insensitive to magnetic field

Spin-and Valley-Dependent Transport in Hybrid System and 2D Dirac Materials.

151 p.In this thesis, we aim to study the spin- and valley-dependent transport in hybrid system and twodimensionalDirac materials.In the first part, I study some spin-dependent and phase-coherent phenomena in hybrid structures.First, I present a full microscopic theory of the spin Hall magnetoresistance (SMR) in non-magneticmetal/magnetic insulator heterostructures. As examples, we apply it into both paramagnetic andferromagnetic SMR, specifically Platinum/Gd3Ga5O12 (Pt/GGG) and Platinum/Europium sulfide(Pt/EuS), respectively. Furthermore, if non-magnetic metal is replaced by nanowire in proximity tosuperconductor below the critical temperature, we can study the interplay of magnetic andsuperconducting proximity effects.In the second part, I explore the possible mechanisms responsible for the classical versions of spinand valley Hall effects, and proposed the schemes for experimental detection of these effects bynonlocal resistance measurements. The understanding of the magnetic properties of nonlocalresistance is significant for the recent controversy about the physical origin of nonlocal resistancemeasured in Hall bar devices made of graphene decorated with absorbates, where the presence oflarge nonlocal resistance and the absence of Hanle oscillation, that is, an oscillation of the nonlocalresistance with in-plane magnetic field, suggest the possibility of the new origin of nonlocalresistance insensitive to magnetic field

Composite rock-breaking of high-pressure CO2 jet & polycrystallinediamond-compact (PDC) cutter using a coupled SPH/FEM Model

Acknowledgments This work was supported by the National Natural Science Foundation of China (Grant No. 52004236), Sichuan Science and Technology Program (Grant No. 2021JDRC0114), the Starting Project of SWPU (Grant No.2019QHZ009), the China Postdoctoral Science Foundation (Grant No.2020M673285), the Open Project Program of Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education (Grant No.202005009KF), and the Chinese Scholarship Council (CSC) funding (CSC NO.202008515107) for the financial support of this work.Peer reviewedPublisher PD

Kármán Vortex Street Driven Membrane Triboelectric Nanogenerator for Enhanced Ultra-Low Speed Wind Energy Harvesting and Active Gas Flow Sensing

[Image: see text] Wind energy harvesting and sensing have a huge prospect in constructing self-powered sensor nodes, but the energy transducing efficiency at low and ultra-low wind speeds is still limited. Herein, we proposed a Kármán vortex street driven membrane triboelectric nanogenerator (KVSM-TENG) for ultra-low speed wind energy harvesting and flow sensing. By introducing Kármán vortex in the KVSM-TENG, the cut-in wind speed of the KVSM-TENG decreased from 1 to 0.52 m/s that is the lowest cut-in wind speed in current TENGs. The instantaneous output density of the KVSM-TENG significantly increased by 1000 times and 2.65 times at the inlet wind speeds of 1 and 2 m/s, respectively. In addition, with the excellent energy transducing performance at the ultra-low speed range, the KVSM-TENG was successfully demonstrated to detect a weak leakage of gas pipeline (∼0.6 m/s) for alarming with high sensitivity. The interaction mechanism between the vortex and KVSM-TENG was systematically investigated. Through the simulation and experimental validation, the enhancement mechanism of vortex dependence on the cylinder diameter and placement location of KVSM-TENG was investigated in detail. The influence of parameters such as membrane length, width, thickness, and electrode gap on the performance of the KVSM-TENG was systematically studied. This work not only provided an ingenious strategy for ultra-low speed wind energy harvesting but also demonstrates the promising prospects for monitoring the air flow in the natural gas exploitation and transportation

Analysis of key issues in construction project management of construction engineering

In recent years, with the continuous rapid growth of China's economy and the acceleration of new urbanization, large-scale basic construction projects are increasing day by day. In the wave of market economy, the importance of construction management has become increasingly prominent. Construction management is not only related to the progress, quality and safety of the entire project, but also has a very close relationship with economic benefits. For this reason, this article analyzes the problems existing in the construction project management of construction projects, and puts forward reasonable solutions for reference only. I hope that readers can do a good job in construction management in the construction of construction projects

Vulnerability Analysis of Interdependent Scale-Free Networks with Complex Coupling

Recent studies have shown that random nodes are vulnerable in interdependent networks with simple coupling. However, relationships in actual networks are interrelated and complex coupling. This paper analyzes the vulnerability of interdependent scale-free networks with complex coupling based on the BA model. The results indicate that these networks have the same vulnerability against the maximum node attack, the load of the maximum node attack, and the random node attack, which explain that the coupling relationship between network nodes is an important factor in network design

Application of multimodal standardized analgesia under the concept of enhanced recovery after surgery in laparoscopic radical colorectal cancer surgery

AimsTo observe the efficacy and safety of multimodal standardized analgesia in patients undergoing laparoscopic radical colorectal cancer surgery.MethodsA prospective, double-blind, randomized study of patients who were admitted to our hospital between December 2020 and March 2022 with a diagnosis of colorectal cancer and who intended to undergo elective laparoscopic radical colorectal cancer surgery was conducted. The participants were randomly divided into two intervention groups, namely, a multimodal standardized analgesia group and a routine analgesia group. In both groups, the visual analogue scale (VAS) pain scores while resting at 6 h, 24 h, 48 h and 72 h and during movement at 24 h, 48 h and 72 h; the number of patient controlled intravenous analgesia (PCIA) pump button presses and postoperative recovery indicators within 3 days after surgery; the interleukin-6 (IL-6) and C-reactive protein (CRP) levels on the 1st and 4th days after surgery; and the incidence of postoperative adverse reactions and complications were recorded.ResultsCompared with the control group, the multimodal standardized analgesia group had significantly lower VAS pain scores at different time points while resting and during movement (P<0.05), significantly fewer PCIA pump button presses during the first 3 postoperative days (P<0.05), and significantly lower IL-6 and CRP levels on the 1st postoperative day (P<0.05). There was no statistically significant difference in the time to out-of-bed activity, the time to first flatus, the IL-6 and CRP levels on the 4th postoperative day or the incidence of postoperative adverse reactions and complications between the two groups (P >0.05).ConclusionFor patients undergoing laparoscopic radical colorectal cancer surgery, multimodal standardized analgesia with ropivacaine combined with parecoxib sodium and a PCIA pump had a better analgesic effect, as it effectively inhibited early postoperative inflammatory reactions and promoted postoperative recovery and did not increase the incidence of adverse reactions and complications. Therefore, it is worthy of widespread clinical practice

Large and tunable magnetoresistance in van der Waals Ferromagnet/Semiconductor junctions

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe3GeTe2/GaSe/Fe3GeTe2 MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of two-dimensional ferromagnets in semiconductor-based vdW junctions offers gate-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not just the magnitude, but also the TMR sign is tuned by the applied bias or the semiconductor thickness, enabling modulation of highly spin-polarized carriers in vdW semiconductors

Large and tunable magnetoresistance in van der Waals ferromagnet/semiconductor junctions

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe3GeTe2/GaSe/Fe3GeTe2 MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of semiconductors into the MTJs offers energy-band-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not only the magnitude of the TMR is tuned by the semiconductor thickness but also the TMR sign can be reversed by varying the bias voltages, enabling modulation of highly spin-polarized carriers in vdW semiconductors