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Comparative analyses of mitogenomes in the social bees with insights into evolution of long inverted repeats in the Meliponini
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作者 Yu-Ran Li Zheng-Wei Wang +1 位作者 Richard T.Corlett Wen-Bin Yu 《Zoological Research》 SCIE CSCD 2024年第1期160-175,共16页
The insect mitogenome is typically a compact circular molecule with highly conserved gene contents.Nonetheless,mitogenome structural variations have been reported in specific taxa,and gene rearrangements,usually the t... The insect mitogenome is typically a compact circular molecule with highly conserved gene contents.Nonetheless,mitogenome structural variations have been reported in specific taxa,and gene rearrangements,usually the tRNAs,occur in different lineages.Because synapomorphies of mitogenome organizations can provide information for phylogenetic inferences,comparative analyses of mitogenomes have been given increasing attention.However,most studies use a very few species to represent the whole genus,tribe,family,or even order,overlooking potential variations at lower taxonomic levels,which might lead to some incorrect inferences.To provide new insights into mitogenome organizations and their implications for phylogenetic inference,this study conducted comparative analyses for mitogenomes of three social bee tribes(Meliponini,Bombini,and Apini)based on the phylogenetic framework with denser taxonomic sampling at the species and population levels.Comparative analyses revealed that mitogenomes of Apini and Bombini are the typical type,while those of Meliponini show diverse variations in mitogenome sizes and organizations.Large inverted repeats(IRs)cause significant gene rearrangements of protein coding genes(PCGs)and rRNAs in Indo-Malay/Australian stingless bee species.Molecular evolution analyses showed that the lineage with IRs have lower dN/dS ratios for PCGs than lineages without IRs,indicating potential effects of IRs on the evolution of mitochondrial genes.The finding of IRs and different patterns of gene rearrangements suggested that Meliponini is a hotspot in mitogenome evolution.Unlike conserved PCGs and rRNAs whose rearrangements were found only in the mentioned lineages within Meliponini,tRNA rearrangements are common across all three tribes of social bees,and are significant even at the species level,indicating that comprehensive sampling is needed to fully understand the patterns of tRNA rearrangements,and their implications for phylogenetic inference. 展开更多
关键词 Social bees PHYLOGENY Mitogenome structure Gene rearrangement Inverted repeats
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Control of GaN inverted pyramids growth on c-plane patterned sapphire substrates
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作者 Luming Yu Xun Wang +8 位作者 Zhibiao Hao Yi Luo Changzheng Sun Bing Xiong Yanjun Han Jian Wang Hongtao Li Lin Gan Lai Wang 《Journal of Semiconductors》 EI CAS CSCD 2024年第6期92-96,共5页
Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane... Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane patterned sapphire substrates(PSS)by metal organic vapor phase epitaxy(MOVPE).The influences of growth conditions on the surface morphol-ogy are experimentally studied and explained by Wulff constructions.The competition of growth rate among{0001},{1011},and{1122}facets results in the various surface morphologies of GaN.A higher growth temperature of 985°C and a lowerⅤ/Ⅲratio of 25 can expand the area of{}facets in GaN inverted pyramids.On the other hand,GaN inverted pyramids with almost pure{}facets are obtained by using a lower growth temperature of 930℃,a higherⅤ/Ⅲratio of 100,and PSS with pattern arrangement perpendicular to the substrate primary flat. 展开更多
关键词 inverted pyramids GAN MOVPE crystal growth competition model
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Significance of including lid thickness and particle shape factor in numerical modeling for prediction of particle trap efficiency of invert trap
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作者 Salman Beg Deo Raj Kaushal 《Water Science and Engineering》 EI CAS CSCD 2024年第2期166-176,共11页
Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sedime... Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sediment build-up by catching sediment load.Previous three-dimensional(3D)computational studies have examined the particle trapping performance of invert traps of different shapes and depths under varied sediment and flow conditions,considering particles as spheres.For two-dimensional and 3D numerical modeling,researchers assumed the lid geometry to be a thin line and a plane,respectively.In this 3D numerical study,the particle trapping efficiency of a slotted irregular hexagonal invert trap fitted at the flume bottom was examined by incorporating the particle shape factor of non-spherical sewage solid particles and the thicknesses of upstream and downstream lids over the trap in the discrete phase model of the ANSYS Fluent 2020 R1 software.The volume of fluid(VOF)and the realizable k-turbulence models were used to predict the velocity field.The two-dimensional particle image velocimetry(PIV)was used to measure the velocity field inside the invert trap.The results showed that the thicknesses of upstream and downstream lids affected the velocity field and turbulent kinetic energy at all flow depths.The joint impact of the particle shape factor and lid thickness on the trap efficiency was significant.When both the lid thickness and particle shape factor were considered in the numerical modeling,trap efficiencies were underestimated,with relative errors of-8.66%to-0.65%in comparison to the experimental values of Mohsin and Kaushal(2017).They were also lower than the values predicted by Mohsin and Kaushal(2017),which showed an overall overestimation with errors of-2.3%to 17.4%. 展开更多
关键词 Invert trap Lid thickness Particle image velocimetry Particle shape factor Turbulent kinetic energy Scanning electron microscope
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Permanent Magnet Temperature Estimation for PMSMs Using Virtual Position-offset Injection
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作者 Beichen Ding Yuting Lu +2 位作者 Kaide Huang Guodong Feng Chunyan Lai 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期51-60,共10页
This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is math... This paper proposes a virtual position-offset injection based permanent magnet temperature estimation approach for permanent magnet synchronous machines(PMSMs). The concept of virtual position-offset injection is mathematically transforming the machine model to a virtual frame with a position-offset. The virtual frame temperature estimation model is derived to calculate the permanent magnet temperature(PMT) directly from the measurements with computation efficiency. The estimation model involves a combined inductance term, which can simplify the establishment of saturation compensation model with less measurements. Moreover, resistance and inverter distorted terms are cancelled in the estimation model, which can improve the robustness to the winding temperature rise and inverter distortion. The proposed approach can achieve simplified computation in temperature estimation and reduced memory usage in saturation compensation. While existing model-based approaches could be affected by either the need of resistance and inverter information or complex saturation compensation. Experiments are conducted on the test machine to verify the proposed approach under various operating conditions. 展开更多
关键词 PMSM Magnet temperature estimation Virtual position offset injection Inverter nonlinearity
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Reduced-Order Observer-Based LQR Controller Design for Rotary Inverted Pendulum
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作者 Guogang Gao LeiXu +2 位作者 Tianpeng Huang Xuliang Zhao Lihua Huang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期305-323,共19页
The Rotary Inverted Pendulum(RIP)is a widely used underactuated mechanical system in various applications such as bipedal robots and skyscraper stabilization where attitude control presents a significant challenge.Des... The Rotary Inverted Pendulum(RIP)is a widely used underactuated mechanical system in various applications such as bipedal robots and skyscraper stabilization where attitude control presents a significant challenge.Despite the implementation of various control strategies to maintain equilibrium,optimally tuning control gains to effectively mitigate uncertain nonlinearities in system dynamics remains elusive.Existing methods frequently rely on extensive experimental data or the designer’s expertise,presenting a notable drawback.This paper proposes a novel tracking control approach for RIP,utilizing a Linear Quadratic Regulator(LQR)in combination with a reduced-order observer.Initially,the RIP system is mathematically modeled using the Newton-Euler-Lagrange method.Subsequently,a composite controller is devised that integrates an LQR for generating nominal control signals and a reduced-order observer for reconstructing unmeasured states.This approach enhances the controller’s robustness by eliminating differential terms from the observer,thereby attenuating unknown disturbances.Thorough numerical simulations and experimental evaluations demonstrate the system’s capability to maintain balance below50Hz and achieve precise tracking below1.4 rad,validating the effectiveness of the proposed control scheme. 展开更多
关键词 Rotary inverted pendulum(RIP) linear quadratic regulator(LQR) reduced-order observer states estimate
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Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy
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作者 Soomal Rafique Nadeem Khan Momin Siddique 《Journal of Biosciences and Medicines》 2024年第2期303-310,共8页
Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms an... Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy. 展开更多
关键词 West Nile Virus encephalitis WNV Hyperacute T-Waves Takotsubo Cardiomyopathy Atypical/Inverted Variant of Stress-Induced Cardiomyopathy CMP
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Estimating the Input Power of a Power Plant Using the Efficiency of the Inverter
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作者 Toussaint Tilado Guingane Sosthène Tassembedo +3 位作者 Eric Korsaga Dominique Bonkoungou Zacharie Koalaga François Zougmore 《Smart Grid and Renewable Energy》 2024年第3期99-106,共8页
The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation... The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation systems and proposes an approach based on the efficiency formula widely documented in the literature. In the absence of input data, this method makes it possible to estimate the plant’s input power using data extracted from the site, in particular that provided by the Ministry of the Environment. The importance of this study lies in the need to accurately determine the input power in order to assess the overall performance of the energy system. 展开更多
关键词 ESTIMATION Data MISSING INPUT Power EFFICIENCY INVERTER
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Benign Nasosinus Tumors: Epidemiological, Clinical, Morphological, Therapeutic, and Evolutionary Aspects at the Adolphe SICE General Hospital in Pointe-Noire (Congo-Brazzaville)
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作者 Sylvain Diembi Sydney Frousse Christian Ngatali +4 位作者 Harol Boris Otouana Gérard Chidrel Gouoni Franck Itiere Odzili Donatien Moukassa Gontran Ondzotto 《Open Journal of Pathology》 2024年第1期1-10,共10页
Introduction: Benign nasosinus tumors (BNST) of epithelial origin are relatively rare and arise from the various lining tissues of the nasal and sinus cavities, and from glands developed from these epithelial invagina... Introduction: Benign nasosinus tumors (BNST) of epithelial origin are relatively rare and arise from the various lining tissues of the nasal and sinus cavities, and from glands developed from these epithelial invaginations. These include nasosinusal polyps, pleiomorphic adenoma and inverted papilloma. The aim of our study was to investigate the epidemiological, clinical, morphological, therapeutic, and evolutionary particularities of these three clinical entities, including two tumors with the potential for progressive malignancy (pleiomorphic adenoma and inverted papilloma) and one strictly benign tumor with a favorable evolution (nasosinus polyp or Schneider polyp). Materials and Methods: This was a retrospective, analytical, cross-sectional study conducted from January 1, 2006 to December 31, 2019 (13 years), in the Department of Otolaryngology and Cervicofacial Surgery at Adolphe SICE Hospital, Pointe-Noire, Congo-Brazzaville. Results: During the study period, 74 patients were registered for a nasosinus tumor, of which 23 were benign tumors of epithelial origin (31%) distributed as follows: 15 cases of nasosinus polyp, 5 cases of pleomorphic adenoma and 3 cases of inverted papilloma. The mean age was 42.5 for polyps, with an estimated median of 38, and 42.9 for the other two entities (pleomorphic adenoma and inverted papilloma), with an estimated median of 41. Nasosinus allergy accounted for 17% of cases, followed by chronic sinusitis (12%);however, in 49% of cases, the patient’s history was not specified. There was no sexual predominance, the sex ratio being 1.08. Occupation, socio-economic level, and education had no impact on the development of these tumors. Most of our patients (52%, 12 cases) had a consultation delay of more than one (1) year, whatever the histological nature of the tumor. The complete nasosinus syndrome (NSS) included nasal obstruction, rhinorrhea, epistaxis, and anosmia, and was found in 19 cases (83%), most often reflecting a nasosinus polyp. CT scans were performed in all patients, with hyperdense images predominating in 22 cases. Management of benign nasosinus tumors was mainly surgical. Postoperative management was straightforward in 15 cases (65%). Conclusion: Benign nasosinus tumors are dominated by nasosinus polyps. Management of these tumors is essentially surgical, with the best clinical outcome. 展开更多
关键词 Nasosinus Polyp Pleomorphic Adenoma Inverted Papilloma Epidemiology Clinical Features Therapeutic Management
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Roller Screw and Threaded Chain Speed Reducer: An Experimental Evaluation
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作者 Filiberto Gutiérrez 《Modern Mechanical Engineering》 2024年第1期1-11,共11页
We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuratio... We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46. 展开更多
关键词 Speed Reducer Inverted Roller Screw Chain Drive Threaded Chain Drive
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Model Predictive Control for Cascaded H-Bridge PV Inverter with Capacitor Voltage Balance
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作者 Xinwei Wei Wanyu Tao +4 位作者 Xunbo Fu Xiufeng Hua Zhi Zhang Xiaodan Zhao Chen Qin 《Journal of Electronic Research and Application》 2024年第2期79-85,共7页
We designed an improved direct-current capacitor voltage balancing control model predictive control(MPC)for single-phase cascaded H-bridge multilevel photovoltaic(PV)inverters.Compared with conventional voltage balanc... We designed an improved direct-current capacitor voltage balancing control model predictive control(MPC)for single-phase cascaded H-bridge multilevel photovoltaic(PV)inverters.Compared with conventional voltage balanc-ing control methods,the method proposed could make the PV strings of each submodule operate at their maximum power point by independent capacitor voltage control.Besides,the predicted and reference value of the grid-connected current was obtained according to the maximum power output of the maximum power point tracking.A cost function was con-structed to achieve the high-precision grid-connected control of the CHB inverter.Finally,the effectiveness of the proposed control method was verified through a semi-physical simulation platform with three submodules. 展开更多
关键词 Model predictive control(MPC) Photovoltaic system Cascaded H-bridge(CHB)inverter Capacitor voltage balance
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Zeno and the Wrong Understanding of Motion—A Philosophical-Mathematical Inquiry into the Concept of Finitude as a Peculiarity of Infinity
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作者 Andreas Herberg-Rothe 《Journal of Applied Mathematics and Physics》 2024年第3期912-929,共18页
In contrast to the solutions of applied mathematics to Zeno’s paradoxes, I focus on the concept of motion and show that, by distinguishing two different forms of motion, Zeno’s apparent paradoxes are not paradoxical... In contrast to the solutions of applied mathematics to Zeno’s paradoxes, I focus on the concept of motion and show that, by distinguishing two different forms of motion, Zeno’s apparent paradoxes are not paradoxical at all. Zeno’s paradoxes indirectly prove that distances are not composed of extensionless points and, in general, that a higher dimension cannot be completely composed of lower ones. Conversely, lower dimensions can be understood as special cases of higher dimensions. To illustrate this approach, I consider Cantor’s only apparent proof that the real numbers are uncountable. However, his widely accepted indirect proof has the disadvantage that it depends on whether there is another way to make the real numbers countable. Cantor rightly assumes that there can be no smallest number between 0 and 1, and therefore no beginning of counting. For this reason he arbitrarily lists the real numbers in order to show with his diagonal method that this list can never be complete. The situation is different if we start with the largest number between 0 and 1 (0.999…) and use the method of an inverted triangle, which can be understood as a special fractal form. Here we can construct a vertical and a horizontal stratification with which it is actually possible to construct all real numbers between 0 and 1 without exception. Each column is infinite, and each number in that column is the starting point of a new triangle, while each row is finite. Even in a simple sine curve, we experience finiteness with respect to the y-axis and infinity with respect to the x-axis. The first parts of this article show that Zeno’s assumptions contradict the concept of motion as such, so it is not surprising that this misconstruction leads to contradictions. In the last part, I discuss Cantor’s diagonal method and explain the method of an inverted triangle that is internally structured like a fractal by repeating this inverted triangle at each column. The consequence is that we encounter two very different methods of counting. Vertically it is continuous, horizontally it is discrete. While Frege, Tarski, Cantor, Gödel and the Vienna Circle tried to derive the higher dimension from the lower, a procedure that always leads to new contradictions and antinomies (Tarski, Russell), I take the opposite approach here, in which I derive the lower dimension from the higher. This perspective seems to fail because Tarski, Russell, Wittgenstein, and especially the Vienna Circle have shown that the completeness of the absolute itself is logically contradictory. For this reason, we agree with Hegel in assuming that we can never fully comprehend the Absolute, but only its particular manifestations—otherwise we would be putting ourselves in the place of the Absolute, or even God. Nevertheless, we can understand the Absolute in its particular expressions, as I will show with the modest example of the triangle proof of the combined horizontal and vertical countability of the real numbers, which I developed in rejection of Cantor’s diagonal proof. . 展开更多
关键词 Zeno False Assumptions about Motion Finitude INFINITY Cantor’s Diagonal Method Inverted Triangle as a Different Method Vertical and Horizontal Dimensions Quantum Theory Relativity of Space and Time Depending on Velocity
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Intrinsic thermal stability of inverted perovskite solar cells based on electrochemical deposited PEDOT 被引量:1
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作者 Congtan Zhu Jing Gao +2 位作者 Tian Chen Xueyi Guo Ying Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第8期445-453,I0011,共10页
Thermal stability of perovskite materials is an issue impairing the long-term operation of inverted perovskite solar cells(PSCs). Herein, the thermal attenuation mechanism of the MAPb I3films that deposited on two dif... Thermal stability of perovskite materials is an issue impairing the long-term operation of inverted perovskite solar cells(PSCs). Herein, the thermal attenuation mechanism of the MAPb I3films that deposited on two different hole transport layers(HTL), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS) and poly(3,4-ethylenedioxythiophene)(PEDOT), is comprehensively studied by applying a heat treatment at 85℃. The thermal stress causes the mutual ions migration of I, Pb and Ag through the device, which leads to the thermal decomposition of perovskite to form Pb I2. Interestingly, we find that I ions tend to migrate more towards electron transport layer(ETL) during heating, which is different with the observation of I ions migration towards HTL when bias pressure is applied. Moreover, the use of electrochemical deposited PEDOT as HTL significantly decreases the defect density of MAPb I3films as compared to PEDOT:PSS supported one. The electrochemical deposition PEDOT has good carrier mobility and low acidity, which avoids the drawbacks of aqueous PEDOT:PSS. Accordingly, the inverted PSCs based on PEDOT show superior durability than that with PEDOT:PSS. Our results reveal detailed degradation routes of a new kind of inverted PSCs which can contribute to the understanding of the failure of thermal-aged inverted PSCs. 展开更多
关键词 Inverted perovskite solarcells CH_(3)NH_(3)Pbl_(3) Thermal stability Electrochemical deposition PEDOT
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Inverted Modelling:An Effective Way to Support Motion Planning of Legged Mobile Robots
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作者 Chenyao Zhao Weizhong Guo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第1期268-279,共12页
This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we he... This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we herein invert the equivalent parallel mechanism.Assuming the leg mechanisms are hybrid links,the body of robot being considered as fixed platform,and ground as moving platform.The motion performance is transformed and measured in the body frame.Terrain and joint limits are used as input parameters to the model,resulting in the representation which is independent of terrains and particular poses in Inverted Modelling.Hence,it can universally be applied to any kind of legged robots as global motion performance framework.Several performance measurements using Inverted Modelling are presented and used in motion performance evaluation.According to the requirements of actual work like motion continuity and stability,motion planning of legged robot can be achieved using different measurements on different terrains.Two cases studies present the simulations of quadruped and hexapod robots walking on rugged roads.The results verify the correctness and effectiveness of the proposed method. 展开更多
关键词 Gait planning Inverted Modelling Legged mobile robot Motion planning WORKSPACE
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对矿产的巨大需求是否会阻碍清洁能源转型升级?
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作者 Mitch Leslie 《Engineering》 SCIE EI CAS CSCD 2023年第12期8-10,共3页
Electric cars purring along the highway differ from nearby internal combustion vehicles not just in their source of power.For parts such as wires and inverters,electric cars require more than twice as much copper as t... Electric cars purring along the highway differ from nearby internal combustion vehicles not just in their source of power.For parts such as wires and inverters,electric cars require more than twice as much copper as their conventional counterparts[1,2].To keep their batteries generating electricity,they need more than double the amount of manganese[1,3].The average electric car also incorporates an assortment of minerals absent from internal combustion vehicles,including nearly 40 kg of nickel,13 kg of cobalt,almost9 kg of lithium,and half a kilogram of rare earth elements such as neodymium,a key component of electric motors[1,4]. 展开更多
关键词 INVERTER NEODYMIUM MANGANESE
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Effect of temperature on heavy ion-induced single event transient on 16-nm FinFET inverter chains
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作者 蔡莉 池雅庆 +10 位作者 叶兵 刘郁竹 贺泽 王海滨 孙乾 孙瑞琪 高帅 胡培培 闫晓宇 李宗臻 刘杰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期504-510,共7页
The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured a... The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature. 展开更多
关键词 heavy ion single event effect single event transient Fin FET inverter chain
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Enhancing performance of inverted quantum-dot light-emitting diodes based on a solution-processed hole transport layer via ligand treatment
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作者 Depeng Li Jingrui Ma +8 位作者 Wenbo Liu Guohong Xiang Xiangwei Qu Siqi Jia Mi Gu Jiahao Wei Pai Liu Kai Wang Xiaowei Sun 《Journal of Semiconductors》 EI CAS CSCD 2023年第9期68-74,共7页
The performance of inverted quantum-dot light-emitting diodes(QLEDs)based on solution-processed hole transport layers(HTLs)has been limited by the solvent-induced damage to the quantum dot(QD)layer during the spin-coa... The performance of inverted quantum-dot light-emitting diodes(QLEDs)based on solution-processed hole transport layers(HTLs)has been limited by the solvent-induced damage to the quantum dot(QD)layer during the spin-coating of the HTL.The lack of compatibility between the HTL’s solvent and the QD layer results in an uneven surface,which negatively impacts the overall device performance.In this work,we develop a novel method to solve this problem by modifying the QD film with 1,8-diaminooctane to improve the resistance of the QD layer for the HTL’s solvent.The uniform QD layer leads the inverted red QLED device to achieve a low turn-on voltage of 1.8 V,a high maximum luminance of 105500 cd/m2,and a remarkable maximum external quantum efficiency of 13.34%.This approach releases the considerable potential of HTL materials selection and offers a promising avenue for the development of high-performance inverted QLEDs. 展开更多
关键词 quantum dots quantum-dot light-emitting diodes inverted structure ligand treatment
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Graphene Bridge Heterostructure Devices for Negative Differential Transconductance Circuit Applications
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作者 Minjong Lee Tae Wook Kim +6 位作者 Chang Yong Park Kimoon Lee Takashi Taniguchi Kenji Watanabe Min‑gu Kim Do Kyung Hwang Young Tack Lee 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第2期161-171,共11页
Two-dimensional van der Waals(2D vdW)material-based heterostructure devices have been widely studied for high-end electronic applications owing to their heterojunction properties.In this study,we demonstrate graphene(... Two-dimensional van der Waals(2D vdW)material-based heterostructure devices have been widely studied for high-end electronic applications owing to their heterojunction properties.In this study,we demonstrate graphene(Gr)-bridge heterostructure devices consisting of laterally series-connected ambipolar semiconductor/Gr-bridge/n-type molybdenum disulfide as a channel material for field-effect transistors(FET).Unlike conventional FET operation,our Gr-bridge devices exhibit nonclassical transfer characteristics(humped transfer curve),thus possessing a negative differential transconductance.These phenomena are interpreted as the operating behavior in two series-connected FETs,and they result from the gate-tunable contact capacity of the Gr-bridge layer.Multi-value logic inverters and frequency tripler circuits are successfully demonstrated using ambipolar semiconductors with narrow-and wide-bandgap materials as more advanced circuit applications based on non-classical transfer characteristics.Thus,we believe that our innovative and straightforward device structure engineering will be a promising technique for future multi-functional circuit applications of 2D nanoelectronics. 展开更多
关键词 Graphene bridge Heterostructure device Non-classical transfer characteristics Multi-value logic inverter Frequency tripler
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Centralized-local PV voltage control considering opportunity constraint of short-term fluctuation
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作者 Hanshen Li Wenxia Liu Lu Yu 《Global Energy Interconnection》 EI CAS CSCD 2023年第1期81-91,共11页
This study proposes a two-stage photovoltaic(PV)voltage control strategy for centralized control that ignores short-term load fluctuations.In the first stage,a deterministic power flow model optimizes the 15-minute ac... This study proposes a two-stage photovoltaic(PV)voltage control strategy for centralized control that ignores short-term load fluctuations.In the first stage,a deterministic power flow model optimizes the 15-minute active cycle of the inverter and reactive outputs to reduce network loss and light rejection.In the second stage,the local control stabilizes the fluctuations and tracks the system state of the first stage.The uncertain interval model establishes a chance constraint model for the inverter voltage-reactive power local control.Second-order cone optimization and sensitivity theories were employed to solve the models.The effectiveness of the model was confirmed using a modified IEEE 33 bus example.The intraday control outcome for distributed power generation considering the effects of fluctuation uncertainty,PV penetration rate,and inverter capacity is analyzed. 展开更多
关键词 ADN Inverter control Short-term volatility Chance constraint optimization Centralized-local control
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Recent progress of inverted organic-inorganic halide perovskite solar cells
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作者 Dongyang Li Yulan Huang +4 位作者 Zhiwei Ren Abbas Amini Aleksandra B.Djurišic Chun Cheng Gang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期168-191,共24页
In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide ... In recent years,inverted perovskite solar cells(IPSCs)have attracted significant attention due to their low-temperature and cost-effective fabrication processes,hysteresis-free properties,excellent stability,and wide application.The efficiency gap between IPSCs and regular structures has shrunk to less than 1%.Over the past few years,IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs.This review provides an overview of recent improvements in the efficiency of IPSCs,including interface engineering and novel film production techniques to overcome critical obstacles.Tandem and integrated applications of IPSCs are also summarized.Furthermore,prospects for further development of IPSCs are discussed,including the development of new materials,methods,and device structures for novel IPSCs to meet the requirements of commercialization. 展开更多
关键词 Inverted perovskite solar cells Interface engineering Additive engineering Tandem solar cells Integrated solar cells
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High frequency doubling efficiency THz GaAs Schottky barrier diode based on inverted trapezoidal epitaxial cross-section structure
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作者 刘晓宇 张勇 +5 位作者 王皓冉 魏浩淼 周静涛 金智 徐跃杭 延波 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期464-469,共6页
A high-performance terahertz Schottky barrier diode(SBD)with an inverted trapezoidal epitaxial cross-sectional structure featuring high varactor characteristics and reverse breakdown characteristics is reported in thi... A high-performance terahertz Schottky barrier diode(SBD)with an inverted trapezoidal epitaxial cross-sectional structure featuring high varactor characteristics and reverse breakdown characteristics is reported in this paper.Inductively coupled plasma dry etching and dissolution wet etching are used to define the profile of the epitaxial layer,by which the voltage-dependent variation trend of the thickness of the metal-semiconductor contact depletion layer is modified.The simulation of the inverted trapezoidal epitaxial cross-section SBD is also conducted to explain the physical mechanism of the electric field and space charge region area.Compared with the normal structure,the grading coefficient M increases from 0.47 to 0.52,and the capacitance modulation ratio(C^(max)/C_(min))increases from 6.70 to 7.61.The inverted trapezoidal epitaxial cross-section structure is a promising approach to improve the variable-capacity ratio by eliminating the accumulation of charge at the Schottky electrode edge.A 190 GHz frequency doubler based on the inverted trapezoidal epitaxial cross-section SBD also shows a doubling efficiency of 35%compared to that 30%of a normal SBD. 展开更多
关键词 inverted trapezoidal epitaxial cross-section structure DOUBLER Schottky barrier diode(SBD) GAAS terahertz capacitance modulation ratio
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