Upgraded System Research Articles

Abstract 4125996: Outcomes Of Transvenous Lead Extraction As a Function Of Lead Dwell Time: Does Risk Plateau With Very Old Leads?

Introduction: Longer lead dwell time is associated with worse outcomes during transvenous lead extraction (TLE). It has been suggested that risk may plateau beyond a certain dwell time but data on this are lacking. Methods: We identified all TLE procedures at Emory Healthcare from 2007-2023. Clinical characteristics and procedural details were collected from medical records. Procedural outcomes were reported using the 2017 HRS/ACC/AHA consensus statement on TLE. Procedural success was defined as complete removal of all targeted lead hardware without any major complications. Clinical success was defined as retention of a small portion (<4 cm) of targeted lead which does not negatively impact the outcome of the procedure. Results: We identified 1,717 TLE procedures. Mean patient age at extraction was 64.6 ± 15.1 yrs, 61.4% were male, 53% had ICD leads and 21% had CRT systems. Extraction indications included lead malfunction (46%), infection (38%) and venous occlusion with need for system upgrade (11%). The dwell time of the oldest lead targeted for extraction was < 1 yr (n=326, 19%), 1-5 yrs (n=633, 36.9%), 5-10 yrs (n=467, 27.2%), 10-15 yrs (n=178, 10.4%), 15-20 yrs (n=71, 4.1%) and >20 yrs (n=42, 2.4%). Procedural and clinical success rates decreased with longer lead dwell time (Figure 1A). Success rates were excellent (>95%) among leads <5 yrs old whereas success rates dropped to the 70-75% range for leads >20 years old. Most clinical failures among very old leads were due to inability to remove all lead material in the setting of infection. Across the entire cohort, the major complication rate was 1.3% and procedural death rate was 0.5%. Complications increased with increased lead dwell time (Figure 1B). Peri-procedural death occurred in 2.8% of cases with dwell times of 15-20 yrs. There were no major complications or deaths among dwell times of >20 yrs, however, the vast majority of these were pacemakers, not ICDs. Conclusion: TLE success rates decrease and complication rates increase with increased lead dwell time, without any clear evidence of a plateau effect. These data have implications for making decisions about abandoning vs. extracting redundant leads.

Exploration and Practice on the Construction of Engineering Training Centers in Applied Undergraduate Universities

Based on the exploration of the reform and development practice of the Engineering Training Center, with the reform of talent cultivation concept as the core, the upgrading of teaching system and the drive of entrepreneurship education as the path, and the innovation and entrepreneurship education platform and entrepreneurship competition as the starting point, the focus is on cultivating students' self-learning ability, practical hands-on ability, innovative development ability, and ability to solve complex engineering problems, achieving the transformation of knowledge into ability. The practical results have shown that the Engineering Training Center has achieved significant results in cultivating students' innovation, practical skills, abilities, and engineering qualities.

Continuous evolution of user-defined genes at 1 million times the genomic mutation rate.

When nature evolves a gene over eons at scale, it produces a diversity of homologous sequences with patterns of conservation and change that contain rich structural, functional, and historical information about the gene. However, natural gene diversity accumulates slowly and likely excludes large regions of functional sequence space, limiting the information that is encoded and extractable. We introduce upgraded orthogonal DNA replication (OrthoRep) systems that radically accelerate the evolution of chosen genes under selection in yeast. When applied to a maladapted biosynthetic enzyme, we obtained collections of extensively diverged sequences with patterns that revealed structural and environmental constraints shaping the enzyme's activity. Our upgraded OrthoRep systems should support the discovery of factors influencing gene evolution, uncover previously unknown regions of fitness landscapes, and find broad applications in biomolecular engineering.

Upgrade of the PandaX-4T online data quality monitoring system and perspectives for future multi-tons PandaX upgrades

Upgrade of the PandaX-4T online data quality monitoring system and perspectives for future multi-tons PandaX upgrades

Thermal hydraulic and material analysis of upgraded flat-type Graphite divertor mock-up for Pakistan Spherical Tokamak (PST)

The design of a divertor is critically dependent on managing power deposition, erosion effects, and plasma configuration. An upgraded double-null divertor configuration has been developed for the Pakistan Spherical Tokamak (PST), featuring graphite targets that are actively cooled and designed to withstand a peak heat flux of 0.3 MW/m² at a pressure of 0.1 MPa. This paper presents a comprehensive thermal-hydraulic and material analysis for the upgraded flat-type divertor mock-up system, covering aspects such as material surface heat load, peak temperature rise (∆T °C) on the mock-up, and surface temperature increase in the cooling channel. The analysis includes total deformation (mm) and equivalent strain for the inner vertical target (IVT), outer vertical target (OVT), and dome structure, along with material comparison. The recommended SST K-ω turbulence model is utilized in the pressure-based transient analysis, with an inlet velocity of 1.5 m s-1 and an inlet temperature of 16.8 °C. A comparative study of the material and thermal-hydraulic analyses was performed using CFD and RELAP5. The findings reveal that graphite is more suitable than tungsten for the PST's upgraded divertor system, demonstrating its effectiveness as the preferred surface material to address heat enhancement challenges in the PST.

Hybrid Testing System Development for Single Point Mooring Lines FOWT’s

Abstract To advance the development of various concepts for floating offshore wind turbines, it is imperative to have access to experimental data. These data are used in the validation of the tools for the simulation of floating turbines and also for the tuning of the models. CENER has developed a hybrid testing methodology that enhances the performance of wave basin tests for scaled models of Floating Offshore Wind Turbines (FOWTs). This approach allows us to apply forces and moments from the wind turbine to the floating platform without needing to replicate wind within the testing facility or create a complex model of the wind turbine rotor. However, when it comes to testing single point moored (SPM) platforms, a unique challenge arises. These platforms have an additional degree of freedom as they can freely rotate around the vertical axis of their mooring attachment (yaw degree of freedom). These type of platforms can present important misalignments with respect to the wind depending on the combination of wind, wave and current directions. Consequently, accurately capturing the impact of misalignment on platform dynamics, especially in yaw, is essential to assess the platform’s ability to self-align with the wind direction, a key factor known as weathervaning capacity. The X1Wind platform is an innovative floating wind system, based on a single point mooring solution with a downwind wind turbine configuration that allows it to be passively self-orientated. The concept has been extensively tested on prototypes at real sea conditions as well as on scaled models at wave basins. For the last wave basin testing campaign, X1Wind has entrusted CENER with the development of the hybrid testing methodology adapted to the requirements of SPM platforms. The testing campaign has covered different wave and wind conditions, including misalignment scenarios and has shown a good dynamic behavior of the platform on yaw. This study outlines the advancements made in the CENER Software-in-the-Loop (SiL) hybrid testing system for wave basin tests of SPM platforms. In order to correctly introduce the direction of the aerodynamic forces on the wind turbine under misaligned conditions, improvements on the software and hardware (loads actuator) of the SiL system were developed and tested. An actuator system consisting of 6 propellers was used. The numerical model that calculates the rotor aerodynamic loading were expanded to take into consideration the direction of the aerodynamic loads with respect to the platform. Additionally, the drag of the wind over the tower and other platform elements must be considered, as they can play a relevant role in the generation of the weathervaning moment. The study concludes that the use of the upgraded SiL hybrid testing system is an effective and afordable solution for the testing of scaled SPM platforms at wave basin facilities. It also summarizes the different considerations that the system has to overcome for the particularity of this type of testing application.

Long-term follow-up of single-chamber atrial pacing - system upgrade and wenckebach block point behavior: potential implications for leadless AAI pacing?

Abstract Introduction Until recently leadless pacemakers (PM) did not support atrial pacing. A novel dual chamber leadless PM system now provides treatment option for a wide range of indications. Single-chamber atrial stimulation (AAI) for the treatment of symptomatic sick sinus syndrome (SSS) is scarcely used due to concerns about the potential development of atrioventricular block (AVB) and development of paroxysmal atrial fibrillation (AF). Long-term follow-up data of AAI-PM is however scarce. Little is known about the role of serial Wenckebach block point (WBP) measurements in AAI-PM patients for risk stratification. Purpose To assess the incidence of dual chamber upgrade of patients treated with AAI-PM for SSS during long-term follow-up and to investigate the role of serial WBP measurements for risk stratification. Methods Prospectively enrolled patients undergoing implantation of an AAI-PM between October 2002 and December 2023. WBP was measured at implantation and serially during follow up. Results We included a total of 178 patients, of which 58% were female and the median age at implantation was 78 [IQR 71 – 83] years. The median follow-up duration was 6.5 [IQR 2.0 – 9.7] years. 24 patients (13.5%) received a system upgrade to DDD including 3 patients (1.7%) with a mode change to ventricular pacing only (VVI). Adjusted for years of follow-up the upgrade rate was 2.1% per year. Median time to system upgrade was 5.2 [IQR 1.6 – 8.7] years. Reasons for system upgrade were high-degree AVB (38%), low WBP (17%), atrial arrhythmias (33%), unclear syncope (8%) and infection (4%). Median WBP at implantation was 130 [120 – 140] bpm, showing a significant decline over time in the upgrade-group with 105 [95 – 130] bpm compared to the rest of the cohort with 130 [120-130] bpm (p = 0.009). A decline in WBP >20 bpm was found in 17.9% patients and a decline of 10-20 bpm in 33.7% of patients. New-onset atrial arrythmias were found in 36 patients (20%), 29% in the upgrade group and 19% in the rest of the cohort (p = 0.3). Neither age at implantation, sex, WBP at implantation, nor atrial arrhythmia prior to implantation were predictive for the need of a future system upgrade. Conclusion In this cohort of patients undergoing AAI-PM implantation for SSS, a system upgrade was required in 2% per year. The WBP remained stable in 48% of patients. Therefore, AAI-PM due to SSS emerges as a judicious and secure therapeutic modality, warranting increased consideration in the light of new treatment options for leadless pacing.

Economic evaluation of kinetic energy storage systems as key technology of reliable power grids.

In recent years, energy-storage systems have become increasingly important, particularly in the context of increasing efforts to mitigate the impacts of climate change associated with the use of conventional energy sources. Renewable energy sources are an environmentally friendly source of energy, but by their very nature, they are not able to supply the required amount of energy in a uniform distribution. This study evaluated the economic efficiency of short-term electrical energy storage technology based on the principle of high-speed flywheel mechanism using vacuum with the help of an innovative approach based on life cycle cost analysis (LCC). The innovative potential of high-speed flywheel energy storage systems (FESS) can be seen in increasing the reliability of the electricity transmission system with the possibility of providing control power to compensate for residual loads caused by volatile renewable power sources and power sinks. Based on the research conducted, the LCC method was selected in this study as the most appropriate method to evaluate the economic efficiency of a high-speed FESS used to compensate for short-term fluctuations in an upgraded electric transmission system. As a result, the adjusted LCC per MWh values were compared with the average intra-hour margin realisable in the Intra-Day OTE Market, while the margin calculation also considered the efficiency of the inertial storage. Under the modelled technical and economic conditions, it was found that a high-speed FESS project that can compensate for short-term fluctuations in the electricity transmission system can be economically efficient in the Czech Republic.

Analyzing the influence of electric vehicle charging scheduling on distribution transformer lifespan

The ongoing growth in global electricity demand and rapid proliferation of electric vehicles (EVs) are posing challenges to the operation of the low voltage power networks and their components. This study aims to analyze the impacts of peak-load demand on the distribution transformers, considering mild and extreme combinations of electric energy demand and localized charging of plug-in EVs under their different penetration levels, hypothesizing that shifting the demand for charging throughout the day can reduce the aging of distribution transformers. The proposed method employs a fuzzy-logic-based tool, which incorporates the influence of ambient temperature, higher harmonics, reactive power compensation, reverse power flows, and overload. Three different charging/discharging modes have been considered: demand charging, off-peak charging, and synergy of off-peak charging and vehicle-to-house technology. The results indicate that off-peak charging emerges as 2.1 times more effective than demand charging in terms of the transformer's loss of life, particularly for ultimate EV penetration of 100 %. It is demonstrated that the utilization of charging scheduling for EVs should be prioritized to defer costly system upgrades and reinforcements, particularly when EV penetration exceeds 50 %.

Optimizing in-situ upgrading of heavy crude oil via catalytic aquathermolysis using a novel graphene oxide-copper zinc ferrite nanocomposite as a catalyst

Unconventional resources, such as heavy oil, are increasingly being explored and exploited due to the declining availability of conventional petroleum resources. Heavy crude oil poses challenges in production, transportation, and refining, due to its high viscosity, low API gravity, and elevated sulfur and metal content. Improving the quality of heavy oil can be achieved through the application of steam injection, which lowers the oil’s viscosity and enhances its flow. However, steam injection alone falls short of meeting the growing demand for higher-quality petroleum products. Catalytic upgrading is therefore being investigated as a viable solution to improve heavy oil quality. This study experimentally investigates the application of two novel catalysts, namely copper-substituted zinc ferrite (ZCFO) synthesized via the sol–gel combustion method and a graphene oxide-based nanocomposite (GO-ZCFO) with different ratios, for catalyzing aquathermolysis reactions in the steam injection process, with the aim of enhancing the in-situ upgrading of heavy oil. These catalysts underwent characterization using X-ray powder diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). Their catalytic performance was assessed utilizing a high-pressure/high-temperature reactor (300 ml), with a comprehensive analysis of the changes in the physical and chemical properties of the heavy oil before and after upgrading. This analysis included measurements of sulfur content, SARA fractions, viscosity, API gravity, and Gas Chromatography (GC) of saturated hydrocarbons and evolved gases. All upgrading experiments, including both catalytic and non-catalytic aquathermolysis processes, were conducted under a reaction time of 6 h, a reaction temperature of 320 °C, and high pressure (86–112 bar). The results indicated that the introduction of the proposed catalysts as additives into the upgrading system resulted in a significant reduction in sulfur content. This, in turn, led to a decrease in resin and asphaltene content, an increase in the content of saturated hydrocarbon, particularly low-molecular-weight alkanes, and ultimately, a reduction in viscosity along with higher API gravity of the crude oil. GO-ZCFO with a weight ratio (50:50) exhibited the best catalytic performance. The heavy crude oil, upgraded with this 50:50 ratio, exhibited significant enhancements, including a 29.26% reduction in sulfur content, a 21.27% decrease in resin content, a 37.60% decrease in asphaltene content, a 46.92% increase in saturated hydrocarbon content, a 66.48% reduction in viscosity, and a 25.49% increase in API gravity. In comparison, the oil upgraded through non-catalytic aquathermolysis showed only marginal improvements, with slight reductions in sulfur content by 5.41%, resin content by 3.60%, asphaltene content by 11.36%, viscosity by 17.89%, and inconsiderable increases in saturated hydrocarbon content by 9.9% and API gravity by 3.02%. The GO-ZCFO, with its high catalytic activity, stands as a promising catalyst that contributes to improving the in-situ upgrading and thermal conversion of heavy crude oil.

The Current Status of Digital Currency Development in China

Abstract: Digital currencies, as innovative products in the field of financial technology, are characterized by their decentralized structure and strong encryption based on blockchain and other technologies. Although your mention of relying on local area networks may be a bit of a misnomer in the broad sense, as the operation of digital currencies relies more broadly on the Internet rather than a single local area network, the concepts of digital encryption and decentralization it emphasizes are accurate. Legal digital currencies, such as the Digital Currency Electronic Payment (DCEP) issued by the People's Bank of China, represent a milestone in this field. They not only integrate the security and transparency of blockchain technology but also achieve a perfect combination of controllable anonymity and legal tender status through the deep integration of the generalized account system with the banking system. The issuance of DCEP marks an important step forward for China in the field of digital currencies and is expected to have a profound impact on the financial market, promoting the modernization and upgrading of the payment system, enhancing transaction efficiency and security, and at the same time, providing the public with more convenient and secure payment options, further integrating into and changing people's daily lifestyles.

Intelligent Connected Vehicle Information Security Risks and Countermeasures

The development of intelligent connected vehicles has promoted the upgrading of the transportation system, but it also brings challenges in information security. This paper analyzes the current information security vulnerabilities of intelligent connected vehicles, including attack methods, security vulnerabilities, and protective measures. Firstly, through the analysis of the existing attack methods and their principles, the potential security vulnerabilities and threats are summarized. Then, based on security and cryptography technology, relevant measures for information security protection are proposed to achieve all-round protection of intelligent connected vehicle information. Finally, The paper puts forward the measures to solve the information security problem of intelligent connected vehicle from three aspects: Encryption and Authentication, Firewall and Intrusion Detection System, and Over-the-air (OTA).

Deep Integration Between Polarimetric Forward-Transmission Fiber-Optic Communication and Distributed Sensing Systems.

The structural health of fiber-optic communication networks has become increasingly important due to their widespread deployment and reliance in interconnected cities. We demonstrate a smart upgrade of a communication system employing a dual-polarization-state polarization shift keying (2-PolSK) modulation format to enable distributed vibration monitoring. Sensing can be conducted without hardware changes or occupying additional communication bandwidth. Experimental results demonstrate that forward transmission-based distributed vibration sensing can coexist with PolSK data transmission without significant deterioration in performance. This proof-of-concept study achieved a sensitivity of 0.4141 μV/με with a limit of detection (LoD) of 563 pε/Hz1/2@100 Hz. The single-span sensing distance can reach up to 121 km (no optical amplification) with a positioning accuracy as small as 874 m. The transmission rate is 300 Mb/s, the QdB is 16.78 dB, and the corresponding BER is 5.202 × 10-12. For demonstration purposes, the tested vibration frequency range is between 100 and 200 Hz.

Performance of 3D trench silicon pixel sensors irradiated up to [formula omitted]

Tracking particles at extreme fluences requires the accurate measurement of the charged particle timing at the pixel level in order to cope with the increased occupancy of HL-LHC experiments. Maintaining this precision throughout the operational life of the detector is crucial. This work demonstrates that the 55×55μm2 wide 150μm thick 3D trench-type pixels, developed by the TimeSPOT Collaboration, maintain the performance of non-irradiated sensors even after exposure to fluences as high as 1⋅10171MeVneqcm−2. The preliminary results of a beam test characterization using minimum ionizing particles at the SPS North area beam facility reveal that the charge collection and the time resolution of the irradiated sensors are comparable to those of non-irradiated ones, by increasing the operational bias voltage. A minor reduction in detection efficiency, approximately 4%, is observed post-irradiation. Currently, 3D trench-type pixels are among the fastest pixel detectors available for tracking charged particles and hold significant promise for future tracking system upgrades. This preliminary evaluation suggests their suitability for use in even harsher radiation environments than High Luminosity Large Hadron Collider (HL-LHC) such as future experiments at the Future Circular Hadron Collider (FCC-hh).

Upgrade of the CMS muon system

This contribution illustrates the four different detector technologies used in the muon spectrometer of the Compact Muon Solenoid (CMS) experiment, installed on the Large Hadron Collider (LHC), and their future upgrades. These have the aim to cope with the scheduled increase of instantaneous luminosity of the LHC in the so-called High-Luminosity LHC phase. CMS Collab. [J. Instrum. 3, S08004 (2008), doi:10.1088/1748-0221/3/08/S08004].

Preventing Overrides of Severe Drug Allergy Alerts Initiative: an Implemented System Upgrade

Administering medications to patients with documented drug hypersensitivity reactions (DHR) poses a significant risk for adverse events, ranging from mild reactions to life-threatening incidents. Electronic healthcare systems have revolutionized the modern clinical decision-making process, with built in warnings. However, as these alerts become a routine part of healthcare provider’s workflow, alert fatigue becomes a challenge. This study was conducted within the Ministry of National Guard Health Affairs (MNGHA), a government healthcare system in Saudi Arabia. A taskforce of experts was formed to develop an electronic path that would prevent unintentional overrides of severe drug allergy alerts. The system underwent rigorous testing, and monitoring parameters were established. We outline the implementation of a system upgrade designed to trigger an alternative interruption in the computerized physician order entry (CPOE) process, distinct from the regular allergy pop-up alerts. The alternate path is activated upon a CPOE with a drug-to-drug match and a documented severe drug allergy symptom, necessitating co-signature form another prescriber before proceeding. The adopted upgrade is a proactive approach to enhance medication safety in electronic healthcare systems, ensuring that serious allergy-related warnings are not overridden, ultimately enhancing patient safety. Further monitoring will confirm the safety and effectiveness of this measure. This study provides a model for institutions seeking to prevent allergy-related harm within their patient population.

Minimizing Business Disruption During Enterprise End-Point OS Upgrade while Maintaining a Robust Security Posture

The deployment of a major end-point operating system (OS) upgrade presents significant challenges for enterprise organizations, requiring a comprehensive strategy to minimize business disruption and maintain a robust security posture. Beyond the operational complexities of managing user productivity and application compatibility, organizations must also proactively address the critical security risks associated with such large-scale technology transitions. Cybercriminals often target organizations undergoing major IT changes, seeking to exploit vulnerabilities that may arise due to shifts in the OS architecture, user workflows, and security controls. This paper outlines practical strategies for executing successful OS upgrade projects that balance operational resilience and cyber risk management. Key focus areas include proactive management of end-point security, comprehensive contingency planning and rollback procedures, strategies to sustain productivity and business continuity, effective end-user training and communication, and valuable insights into the next- generation OS deployment. By focusing on these critical aspects, organizations can navigate major OS upgrade initiatives while preserving vigorous business operations, enhancing end-user experience, and safeguarding sensitive data and systems from costly security incidents.

Approach to Validate ISPM-15 Compliance for Commercial Treatment Certification of Dielectric Standard Heating of Bulk Solid Wood Packing Materials using Radio Frequency

Abstract To substantially reduce the risk of alien invasive species moving to new geographic areas, phytosanitary treatment of wood packaging materials (WPM) in compliance with the International Standard of Phytosanitary Measures No. 15 (ISPM-15) is required by trading partners. Approved treatments include conventional heating, methyl bromide and sulfuryl fluoride fumigation, and dielectric heating (DH). The DH standard was officially adopted in 2013 but has not been practiced commercially due primarily to insufficient operational validation at commercial scale. In 2022, we converted our 50-kW radio frequency (RF) unit with a 1,200-board foot capacity from an oscillator electromagnetic field power generator to a solid-state power supply, which allows for selective power input adjustments during treatment; we also switched from a five-plate to a three-plate winged electrode system to improve heating uniformity. Each loading cycle can treat sufficient material to build ∼94 standard Grocery Manufacturers Association pallets. Our research team characterized the dielectric heating pattern and options for monitoring wood temperatures over a wide-ranging test matrix of WPM that varied by wood species, dimension, moisture content, and loading configuration. We found that this upgraded RF system markedly reduced treatment times and improved heating uniformity, allowing us to develop methods that can be used to verify compliance with ISPM-15 for improved technology transfer to industry. We also discuss the operational cost of RF treatment and make general cost comparisons to conventional heat treatment for WPM.

Investigation of a novel combined ab- and ad- sorption based thermal energy storage and upgrade system

This paper presents a novel sorption-based cycle combining energy storage with energy upgrade to store low-grade heat for long periods and transform it on demand to usable energy at elevated temperatures. The system consists of an ammonia-water absorption system coupled to a resorption thermal transformer using manganese chloride and calcium chloride as the working pair with an ammonia absorbate. The absorption and adsorption systems are charged by separating the constituent sorbent-sorbate pairs, and they remain separated during the transition season. The discharge consists of a two-stage sorption process between the two systems. This work presents a transient thermodynamic model and analysis of the two-stage sorption system. For a typical solar thermal energy input of 106 °C during charging, and ambient temperatures of 5 °C and 25 °C in the winter and summer, respectively, the system is capable of discharging at an average elevated temperature of 62 °C with an energy storage efficiency of 27 %. This system is capable of simultaneously producing heat at a lower temperature by varying the mass flow rate through the high-temperature salt. The energy storage density of the combined system under different conditions is between 71 and 185 kJ kg−1. In comparison with other conventional single-stage thermal energy storage systems, this combination of absorption and adsorption-based storage provides a higher coefficient of performance for a comparable temperature output.

A low heat release cladding pump coupler

Few-mode erbium-doped fiber amplifiers (FM-EDFAs) have opened up the possibility of realizing the next generation of high-capacity, high-rate communication systems. However, the leakage of pump light during continuous operation of the FM-EDFA is likely to cause the temperature of the cladding pump coupler to be too high and thus destabilize the amplifier. In this work, a low heat release cladding pump coupler was designed and the corresponding FM-EDFA was constructed. The cladding pump coupler in the 8 hours of continuous operation of the FM-EDFA is at 27.8 °C for maximum, 23.7 °C for minimum, and 26 °C for average temperatures, respectively, which are in a low-temperature safe transmission state. The FM-EDFA performance test was performed on this basis, and the results show that when the input pump power is 7 W, the maximum gain fluctuation of each mode of FM-EDFA at 1550 nm in 0∼8 hours is only 1.5 dB, the gain of all modes is greater than 23 dB and the differential mode gain (DMG) is less than 2 dB. In addition, the FM-EDFA still has good performance in the C-band after 8 hours of continuous operation. The gain for all modes is greater than 21 dB, DMG is less than 2 dB, and wavelength flatness is 3.6 dB. The low heat release cladding pump coupler is conducive to the stable amplification transmission of FM-EDFA, which is of great significance to achieving the upgrading and expansion of the communication system.