mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Improved Identification Method and Fault Current Limiting Strategy for Commutation Failure in LCC-HVDC

Line-commutated converter based high-voltage direct-current (LCC-HVDC) transmission systems are prone to subsequent commutation failure (SCF), which consequently leads to the forced blocking of HVDC links, affecting the operation of the power system. An accurate commutation failure (CF) identification is fairly vital to the prevention of SCF. However, the existing CF identification methods cause CF misjudge or detection lag, which can limit the effect of SCF mitigation strategy. In addition, earlier approaches to suppressing SCF do not clarify the key factor that determines the evolution of extinction angle during system recovery and neglect the influence. Hence, this paper firstly analyzes the normal commutation process and CF feature based on the evolution topology of converter valve conduction in detail. Secondly, the energy in the leakage inductance of converter transformer is presented to characterize the commutation state of the valves. Then a CF identification method is proposed utilizing the leakage inductance energy. Thirdly, taking the key variable which is crucial to the tendency of extinction angle during the recovery process into account, a fault current limiting strategy for SCF mitigation is put forward. Compared with the original methods, the proposed methods have a better performance in CF identification and mitigation in terms of detection accuracy and mitigation effect. Finally, case study on PSCAD/EMTDC validates the proposed methods.
Three-stage Defensive Framework for Distributed Microgrid Control Against Cyberattacks

With the wide integration of various distributed communication and control techniques, the cyber-physical microgrids face critical challenges raised by the emerging cyberattacks. This paper proposes a three-stage defensive framework for distributed microgrids against denial of service (DoS) and false data injection (FDI) attacks, including resilient control, communication network reconfiguration, and switching of local control. The resilient control in the first stage is capable of tackling simultaneous DoS and FDI attacks when the connectivity of communication network could be maintained under cyberattacks. The communication network reconfiguration method in the second stage and the subsequent switching of local control in the third stage based on the software-defined network (SDN) layer aim to cope with the network partitions caused by cyberattacks. The proposed defensive framework could effectively mitigate the impacts of a wide range of simultaneous DoS and FDI attacks in microgrids without requiring the specific assumptions of attacks and prompt detections, which would not incorporate additional cyberattack risks. Extensive case studies using a 13-bus microgrid system are conducted to validate the effectiveness of the proposed three-stage defensive framework against the simultaneous DoS and FDI attacks.
Recent progress on thermal conductivity of graphene filled epoxy composites

With the rapid development of the electronic industry, the requirements for packaging materials with high thermal conductivity(TC)are getting higher and higher. Epoxy is widely used as package material for electronic package applications. But it's intrinsic TC can't meets the increasing demands. Adding high TC graphene into epoxy matrix is a proper way to reinforce epoxy composites. This review focuses on the filler modification,preparation process and thermal properties of graphene-filled epoxy resin composites. Different ways of covalent and non-covalent modification methods are discussed. The various kinds of graphene coating layer are also summarized. Then we analysis the hybrid filler system in epoxy composite. We hope this review will provide guidance for the development and application of graphene-filled epoxy resin composites.
In vitro 3D malignantmelanoma model for the evaluation of hypericin-loaded oil-in-water microemulsion in photodynamic therapy

Advances in biomimetic three-dimensional (3D) melanomamodels have brought new prospects of drug screening and disease modeling, since their physiological relevancy for recapitulating in vivo tumor architectures is more accurate than traditional two-dimensional (2D) cell culture. Gelatin methacryloyl (GelMA) is widely used as a tissue-engineered scaffold hydrogel for 3D cell culture. In the present study, an in vitro 3D malignant melanoma model based on GelMA was fabricated to evaluate the efficiency of hypericin (Hy)-loaded microemulsion (ME) in photodynamic therapy against melanoma. The ME was produced by the spontaneous emulsification method to enhance the bioavailability of Hy at tumor sites. Hy-loaded MEs were applied to a 3D malignant melanoma model made using 6% GelMA and the co-culture of B16F10 and Balb/c 3T3 cells, followed by crosslinking using violet light (403 nm). The observation revealed excellent cell viability and the presence of F-actin cytoskeleton network. Hy-loaded MEs exhibited higher phototoxicity and cell accumulation (about threefold) than free Hy, and the cells cultured in the 3D system displayed lower susceptibility (about 2.5-fold) than those in 2D culture. These findings indicate that the developed MEs are potential delivery carriers for Hy; furthermore, GelMA hydrogel-based modeling in polydimethylsiloxane (PDMS) molds is a user-friendly and cost-effective in vitro platform to investigate drug penetration and provide a basis for evaluating nanocarrier efficiency for skin cancer and other skin-related diseases.
Modeling of Fault-tolerant Flux-switching Permanent-magnet Machines for Predicting Magnetic and Armature Reaction Fields

The paper develops accurate analytical subdomain models for predicting the magnetic and armature reaction fields in fault-tolerant flux-switching permanent-magnet machines. The entire region is divided into five subdomains, followed by rotor slots, air-gap, stator slots, PM, and external air-gap imported to account for flux leakage. The coil turns and the remanence of magnets are adjusted by keeping the magnetic and electrical loading on the motor constant. The distance between the centers of two adjacent stator slots varies due to the introduction of fault-tolerant teeth. According to the variable separation method, the general solution expression of each region can be determined by solving the partial differential systems of equations. The magnetic field distributions of subdomains are obtained by applying the continuity conditions between adjacent regions. Some analytical field expressions are represented as new forms under armature reaction field condition compared to those under no-load condition. Based on the developed analytical models, the flux density distribution and the electromagnetic performance can be calculated under no-load or armature reaction field condition separately. The finite element analysis is carried out to verify the validity of the proposed analytical model.
Colossal negative magnetoresistance from hopping in insulating ferromagnetic semiconductors

Ferromagnetic semiconductor Ga_(1-x)Mn_x As_(1-y) P_y thin films go through a metal-insulator transition at low temperature where electrical conduction becomes driven by hopping of charge carriers. In this regime, we report a colossal negative magnetoresistance (CNMR) coexisting with a saturated magnetic moment, unlike in the traditional magnetic semiconductor Ga_(1-x) Mn_x As. By analyzing the temperature dependence of the resistivity at fixed magnetic field, we demonstrate that the CNMR can be consistently described by the field dependence of the localization length, which relates to a field dependent mobility edge. This dependence is likely due to the random environment of Mn atoms in Ga_(1-x)Mn_x As_(1-y) P_y which causes a random spatial distribution of the mobility that is suppressed by an increasing magnetic field.
Predicting factors for better outcomes of stable supination external rotation type 2 ankle fractures

Purpose: Stable Weber B ankle fractures are treated by a walking boot for 6 weeks and bearing full weight through the boot as tolerated. The aim of the present study was to assess the outcome parameters of this treatment protocol, evaluate the efficacy of using the walking boot, and investigate any possible predicting factors that could affect the outcomes. Methods: All the patients with stable Weber B ankle fractures, treated in our hospital between January 2018 and December 2018, were prospectively included to the study. The patients were evaluated clinically, and the patient-reported outcome measures data were collected at the 2 and 6 weeks post-injury. Chi square, Spearman's rho test, independent samples and paired sample t-tests were used for the monovariant analysis. Results: A total of 128 consecutive patients (aged 52.2 ± 19.1 years) with supination external rotation type 2 fracture were finally included to the study. At the 2 weeks follow-up, the reported outcome measures scores were in moderate levels, but improved significantly at the 6 weeks follow-up (p < 0.0001). Multivariant analysis revealed that the ability to bear full weight without the boot at the 2 weeks after diagnosis was the only variable, which made statistically unique contribution to the foot and ankle disability index score at the 6 weeks (p = 0.005). Conclusion: Conservative treatment using a walking boot with advice to bear full weight of stable ankle Weber B fractures can bring to good functional outcomes. The ability to bear full weight without the aid of the walking boot at 2 weeks after diagnosis was the only significant predicting factor for better outcomes at 6 weeks after diagnosis.
Anomaly detection of control rod drive mechanism using long short-term memory-based autoencoder and extreme gradient boosting

Anomaly detection for the control rod drive mechanism(CRDM)is key to enhancing the security of nuclear power plant equipment. In CRDM real-time condition-based maintenance, most existing methods cannot deal with long sequences and periodic abnormal events and have poor feature extraction from these data. In this paper, a learning-based anomaly detection method employing a long short-term memory-based autoencoder(LSTM-AE)network and an extreme gradient boosting(XGBoost)algorithm is proposed for the CRDM. The nonlinear and sequential features of the CRDM coil currents can be automatically and efficiently extracted by the LSTM neural units and AE network. The normal behavior LSTM-AE model was established to reconstruct the errors when feeding abnormal coil current signals. The XGBoost algorithm was leveraged to monitor the residuals and identify outliers for the coil currents. The results demonstrate that the proposed anomaly detection method can effectively detect different timing sequence anomalies and provide a more accurate forecasting performance for CRDM coil current signals.
Beam-beam effects and mitigation in a future proton-proton collider

The beam-beam effects in a hadron collider with an unprecedented energy scale were studied. These effects are strongly related to the attainable luminosity of the collider. Long-range interactions were identified as the major factor limiting the dynamic aperture, which is strongly dependent on the crossing angle, β~*, and bunch population. Different mitigation methods of the beam-beam effects were addressed, with a focus on the compensation of long-range interactions by electric current wires. The CEPC-SPPC project is a two-stage large circular collider, with a first-stage circular electron-positron collider(CEPC)and a second-stage super proton-proton collider(SPPC). The design of the SPPC aims to achieve a center-of-mass energy of 75 TeV and peak luminosity of approximately 1 × 10~(35) cm~(-2) s~(-1). We studied the beam-beam effects in the SPPC and tested the effectiveness of the mitigation methods. We found that with compensation using electric current wires, the dynamic aperture is at an acceptable level. Moreover, considering the significant emittance damping in this future proton-proton collider, the beam-beam effects and compensation are more complicated and are studied using long-term tracking. It was found that with a smaller emittance, the head-on interactions with a crossing angle become more prominent in reducing the beam stability, and combined head-on and long-range compensation is needed to improve the beam quality. When the reduction in population owing to burnoff was included, it was found that the coupling between the transverse and longitudinal planes at smaller emittance is the main driving source of the instabilities. Thus, crab cavities and emittance control are also necessary than just the compensation of the long-range interactions to improve the beam stability. This study serves as an example for studying the beam-beam effects in future proton-proton colliders.
Design and preliminary test of tritiated water online detector system based on plastic scintillators

In this study, an online detector system based on plastic scintillators is designed to monitor the activity of tritiated water in the liquid effluents of nuclear power plants. The feasibility of the detector is verified via simulation on Geant4, and the optimal detector structure size is determined. A back-end electronics system is designed, and an experimental measurement platform for b-rays based on a ~(40)KCl solution is constructed. Thirteen ~(40)KCl solutions with different activities ranging from 10 to 4500 Bq/L are measured, and 1300 V is determined as the optimal operating high voltage of the photomultiplier tubes. A linear fit is performed in 10-min counts, and the maximum linear goodness of fit(R~2)achieved is 0.9992. Long-term stability measurements are performed for two detectors, one filled with air and the other with a ~(40)KCl solution exhibiting an activity of 2000 Bq/L. The relative deviation of the counts of the detector system every 10 min is 0.998% when the ~(40)KCl solution is used, and the maximum Gaussian R~2 of the counts is 0.9849.
Capacity Contribution Mechanism of rGO for SnO_2/rGO Composite as Anode of Lithium-ion Batteries

Compared with ordinary graphite anode, SnO_2 possesses higher theoretical specific capacity, rich raw materials and low price. While the severe volume expansion of SnO_2 during lithium-ion extraction/intercalation limits its further application. To solve this problem, in this work the reduced graphene oxide (rGO) was introduced as volume buffer matrix of SnO_2. Herein, SnO_2/rGO composite is obtained through one-step hydrothermal method. Three-dimensional structure of rGO could effectively hinder the polymerization of SnO_2 nanoparticles and provide more lithium storage sites attributed to high specific surface area and density defects. The initial discharge capacity of the composite cathode is 959 mA·h·g~(-1) and the capacity remained at 300 mA·h·g~(-1) after 1000 cycles at 1 C. It proved that the rGO added in the anode has a capacity contribution to the lithium-ion battery. It changes the capacity contribution mechanism from diffusion process dominance to surface driven capacitive contribution. Due to the addition of rGO, the anode material gains stable structure and great conductivity.
Twin and twin intersection phenomena in a creep deformed microalloyed directionally solidified high Nb containing TiAl alloy

The creep behavior of a directionally solidified TiAl alloy with a high Nb content after microalloying by the addition of small amounts of W, Cr, and B elements was investigated by scanning electron microscopy and transmission electron microscopy. By means of directional solidification and microalloying, a TiAl alloy with a fine and uniform microstructure and continuous columnar crystals was obtained. High-density dislocations, deformation nanotwins, and twin intersections were observed in γ lamellae. The results show that, in comparison with the ternary TiAl alloy, the microalloyed high Nb containing TiAl alloy exhibited better creep properties at 760 °C and 275 MPa. The decrease in stacking fault energy can promote dislocation dissociation and the formation of deformation twins, and the twin intersections can hinder the movement of dislocation to enhance the creep performance of the TiAl alloy.
3D flower-like hollow CuS@PANI microspheres with superb X-band electromagnetic wave absorption

Superior electromagnetic (EM) wave absorption properties in 8.2-12.4 GHz (X -band) can be obtained via the effective combination of polyaniline (PANI) and CuS. Herein, novel 3D flower-like hollow CuS@PANI microspheres were fabricated by a solvothermal process followed by in-situ polymerization. EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres in X -band were systematically studied, indicating the minimum reflection loss (RL min) of -71.1 dB and effective absorption bandwidth (EAB) covering 81% of test frequency range were achieved with a thickness of 2.75 mm. Excellent EM wave absorption properties of 3D flower-like hollow CuS@PANI microspheres were mainly ascribed to outstanding impedance matching characteristic and dielectric loss capability (conduction loss, interfacial polarization loss and dipole polarization loss). Moreover, due to the distinctive flower-like hollow structure of CuS@PANI microspheres, an additional wave-absorbing mechanism was provided by increasing the transmission paths of EM waves.
Exploration on the stability conditions in bubble columns by noncooperative game theory

The energy-minimization multiscale (EMMS) model,originally proposed for gas-solid fluidization,features a stability condition to close the simplified conservation equations.It was put forward to physically reflect the compromise of two dominant mechanisms,i.e.,the particle-dominated with minimal potential energy of particles,and the gas-dominated with the least resistance for gas to penetrate through the particle bed.The stability condition was then formulated as the minimization of the ratio of these two physical quantities.Analogously,the EMMS approach was later extended to the gas-liquid flow in bubble columns,termed dual-bubble-size model.It considers the compromise of two dominant mechanisms,i.e.,the liquid-dominated regime with small bubbles,and the gas-dominated regime with large bubbles.The stability condition was then formulated as the minimization of the sum of these two physical quantities.Obviously,the two stability conditions were expressed in different manner,though gas-solid and gas-liquid systems bear some analogy.In addition,both the conditions transform the original multiobjective variational problem into a single-objective problem.The mathematical formulation of stability condition remains therefore an open question.This study utilizes noncooperative game theory and noninferior solutions to directly solve the multi-objective variational problem,aiming to explore the different pathways of compromise of dominant mechanisms.The results show that only keeping the single dominant mechanism cannot capture the jump change of gas holdup,which is associated with flow regime transition.Hybrid of dominant mechanisms,noninferior solutions and noncooperative game theory can predict the flow regime transition.However,the game between the two mechanisms makes the two-bubble structure degenerate and reduce to the single-bubble structure.The game of the three mechanisms restores the two-bubble structure.The exploration on the formulation of stability conditions may help to understand the roles and interactions of different dominant mechanisms in the origin of complexity in multiphase flow systems.
Modeling the optimal compensation capacitance of a giant magnetostrictive ultrasonic transducer with a loosely-coupled contactless power transfer system

The giant magnetostrictive rotary ultrasonic processing system (GMUPS) with a loosely-coupled contactless power transfer (LCCPT) has emerged as a high-performance technique for the processing of hard and brittle materials, owing to its high power density. A capacitive compensation is required to achieve the highest energy efficiency of GMUPS to provide sufficient vibration amplitude when it works in the resonance state. In this study, an accurate model of the optimal compensation capacitance is derived from a new electromechanical equivalent circuit model of the GMUPS with LCCPT, which consists of an equivalent mechanical circuit and an electrical circuit. The phase lag angle between the mechanical and electrical circuits is established, taking into account the non-negligible loss in energy conversion of giant magnetostrictive material at ultrasonic frequency. The change of system impedance characteristics and the effectiveness of the system compensation method under load are analyzed. Both idle vibration experiments and machining tests are conducted to verify the developed model. The results show that the GMUPS with optimal compensation capacitance can achieve the maximum idle vibration amplitude and smallest cutting force. In addition, the effects of magnetic conductive material and driving voltages on the phase lag angle are also evaluated.
低碳旅游:新能源电池在旅游业中的应用

近年来,随着城市建设力度与生活水平的不断提高,人类对能源的需求不断增加,这不但造成了严重的能源短缺问题,而且给自然生态环境保护带来了巨大压力。为进一步减少社会发展对传统不可再生能源的依赖与消耗,研究人员在新能源的开发与应用方面投入了大量的时间与精力,设计、提出并生产了多种新能源设备和新能源供能工具,这在一定程度上缓解了日益严重的能源问题。其中,新能源电池便是时下最为热议的一类新能源技术,该技术通过使用可再生能源及特殊设备进行能量的产生与存储,如光能、风能、潮汐能、热辐能等均可作为该类设备的供能来源。同时,旅游产业作为传统产业中的龙头性行业,在社会发展、劳动力分配、政府税收、城市宣传等多个方面具有重要意义,因此,如何在当今社会进一步推动旅游产业的转型与升级并实现旅游业的健康稳定可持续发展,已成为该领域从业人员及政府相关管理部门较为关心的重要核心问题。
新能源发电企业经济管理模式的规范化

近年,由于国家新能源技术包括风力发电、太阳能发电等的大力发展,我国在这些技术领域都获得了一些不错的成绩,也为这些新能源的基础设施投入了许多经济方面支持,风力发电厂以及太阳能电厂等新能源企业大量投入使用。新能源发电企业作为国民经济的新兴产业,其生产活动直接关系着国家的经济发展,对国家的发展以及国际地位提升也有着重要的作用。国际大环境的重视使得新能源发电企业也面临着很大的挑战,这就要求国内新能源发电企业重视自身的经营管理,建立健全符合新能源发电企业自身特点的内部制度,完善企业内部环境,加强企业抵抗风险的能力,完善新能源发电企业的自我创新能力,保障企业可持续发展的能力,建立有效的变革制度。
自动驾驶汽车实际道路测试系统设计与实现

作为高级别自动驾驶汽车测试评价"三支柱"方法论的测评手段之一,实际道路测试是验证和保障自动驾驶汽车安全、高效执行动态驾驶任务(DDT)不可或缺的环节,是加快自动驾驶汽车平稳落地的必要前提。而实际道路测试过程中所产生海量数据的快速处理和分析,需要借助于大数据和云计算技术作为支撑,从而能够实现实时、准确、便捷地对测试的实施过程和结果进行监控管理与统计分析。从自动驾驶汽车实际道路测试测评的需求分析出发,基于大数据和云计算在自动驾驶路测数据处理方面的技术方案研究,提出了面向于自动驾驶实际道路测试的系统整体技术架构设计。对该技术方案架构下的具体实施流程进行了阐述,并以具备领航辅助驾驶系统的车辆为例开展了技术方案架构的初步实践应用和验证,结果证明所提出的自动驾驶实际道路测试评价技术方案架构具备可行性,研究成果为自动驾驶汽车实际道路测试系统建设提供重要的技术参考和依据,可作为一种规范化方法广泛应用。
传染病房巡视护理机器人系统设计与实现

面向重大传染性疾病护理工作中无人化护理作业需求,针对目前护理工作中医护人员感染风险高、劳动强度大等问题,设计了一种悬挂式轨道传染病房巡视护理机器人。机器人搭载图像分析等多种传感器,可以自动完成巡视任务,结合新型冠状病毒肺炎的临床特点监测、记录和分析病人体征信息,在实验室环境下,验证了样机的巡检、体征监测等功能。
女性青春期常见内分泌疾病诊疗策略专题讨论-女性青春期启动及相关影响因素

青春期由童年结束开始直至达到最终的身高和性成熟,在此期间人体发生了一系列心理-神经-内分泌变化,从而导致性别二态性和配子产生。青春期的启动机制目前尚不明确,涉及中枢神经系统、下丘脑、垂体、肾上腺、性腺及外周内分泌代谢等的共同参与和调控。其中下丘脑神经内分泌调控腺垂体机制的成熟在青春期启动中起到主要作用。青春期的正常持续时间约为5 ~ 6年,男性进入青春期时间明显晚于女性。女性青春期最初启动通常在8.5 ~ 12.5岁(平均10.5岁)出现,男性在9.5 ~ 13.5岁(平均11.5岁)出现,有很多因素可影响青春期启动,从而导致青春期早熟或延迟。
断掌合并断指再植的临床经验探讨

目的探讨断掌合并断指再植的治疗方法和临床疗效。方法2017年1月至2020年7月,宁波市第六医院手外科共收治6例手掌部离断合并指体离断患者,其中1例合并5个手指离断,2例合并4个手指离断,2例合并3个手指离断,1例合并2个手指离断。应用显微外科技术行断掌及断指再植,术后早期行康复锻炼,并定期进行随访,按照中华医学会手外科学会上肢再植功能评定试用标准评价功能恢复情况。结果6例断掌合并断指再植术后全部成活。术后随访6~36(平均15)个月,手掌部部分肌肉挛缩,各断指再植术后指体关节活动稍受限。按照中华医学会手外科学会上肢部分功能评定试用标准评定,结果优1例,良4例,可1例。结论断掌合并断指患者应尽可能通过团队合作,在保证生命体征平稳的情况下尽早再植,精细修复,术后早期行功能锻炼,可取得良好疗效,并有效改善患者生活质量。
琥珀酸脱氢酶缺陷型肾细胞癌一例

总之,SDH缺陷型肾细胞癌是一种非常罕见的肿瘤,与SDH基因种系突变相关,也与副神经节瘤/嗜铬细胞瘤、胃肠道间质瘤或垂体腺瘤相关。年轻男性患者单侧肾脏出现混杂密度肿块,部分呈局灶性多囊改变,局限于肾脏,无肾窦、静脉或肾周脂肪侵犯,增强扫描呈明显不均匀强化,应该想到此病的可能,但最终确诊仍需病理检查。