期刊文献+
共找到885篇文章
< 1 2 45 >
每页显示 20 50 100
Visible light photocatalytic enhanced heterogeneous cobalt catalyzed peroxymonosulfate synergistic process to degradation atrazine:Efficiency,influencing factors,by-products removal and mechanism
1
作者 Qingkong Chen Jieyu Xia +3 位作者 Fengjun Liu Jianping Fan Peng Yan Mika Sillanpää 《Journal of Environmental Sciences》 2026年第1期166-177,共12页
This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degra... This study developed a novel heterogeneous Vis-Photo+Fenton-like system by integrating visible-light-responsive Co_(3)O_(4)/TiO_(2) photocatalysis with peroxymonosulfate(PMS)activation for efficient atrazine(ATZ)degradation.The synergistic process achieved complete ATZ removal within 60 min under near-neutral pH(6.9),outperform-ing individual Fenton-like(39%)and photocatalytic(24%)processes.Key factors influencing the degradation efficiency included light sources(UV>visible),pH(optimal at 6.9),catalyst dosage(0.01 g Co_(3)O_(4)/TiO_(2)),and PMS:ATZ molar ratio(1:2).The system exhibited a synergistic coefficient of 5.03(degradation)and 1.97(miner-alization),attributed to enhanced radical generation and accelerated Co^(3+)/Co^(2+)redox cycling through photoin-duced electron transfer.Intermediate analysis revealed dealkylation,dechlorination,and oxidation pathways,with reduced toxicity of by-products(e.g.,CEAT,CIAT)confirmed by ecotoxicity assessments.The mineralization efficiency(Vis-Photo+Fenton-like)reached 83.1%,significantly higher than that of standalone processes(Fenton-like:43.2%;photocatalysis:30.5%).The catalyst demonstrated excellent stability(nearly 90%recov-ery,<1μg/L Co leaching)and practical applicability.This study provides an efficient,sludge-free,and solar-compatible strategy for eliminating persistent herbicides in water treatment. 展开更多
关键词 Synergistic effect Sulfate radical FENTON-LIKE PHOTOCATALYSIS Visible light Atrazine(ATZ)
原文传递
A Comprehensive Survey on Federated Learning Applications in Computational Mental Healthcare 被引量:1
2
作者 Vajratiya Vajrobol Geetika Jain Saxena +6 位作者 Amit Pundir Sanjeev Singh Akshat Gaurav Savi Bansal Razaz Waheeb Attar Mosiur Rahman Brij B.Gupta 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期49-90,共42页
Mental health is a significant issue worldwide,and the utilization of technology to assist mental health has seen a growing trend.This aims to alleviate the workload on healthcare professionals and aid individuals.Num... Mental health is a significant issue worldwide,and the utilization of technology to assist mental health has seen a growing trend.This aims to alleviate the workload on healthcare professionals and aid individuals.Numerous applications have been developed to support the challenges in intelligent healthcare systems.However,because mental health data is sensitive,privacy concerns have emerged.Federated learning has gotten some attention.This research reviews the studies on federated learning and mental health related to solving the issue of intelligent healthcare systems.It explores various dimensions of federated learning in mental health,such as datasets(their types and sources),applications categorized based on mental health symptoms,federated mental health frameworks,federated machine learning,federated deep learning,and the benefits of federated learning in mental health applications.This research conducts surveys to evaluate the current state of mental health applications,mainly focusing on the role of Federated Learning(FL)and related privacy and data security concerns.The survey provides valuable insights into how these applications are emerging and evolving,specifically emphasizing FL’s impact. 展开更多
关键词 DEPRESSION emotional recognition intelligent healthcare systems mental health federated learning stress detection sleep behaviour
在线阅读 下载PDF
Society,Migration and the Trans-Cultural Impact:A Hermeneutic Perspective
3
作者 Andre Shih Tzu Yu Allison Lin 《Sociology Study》 2025年第6期261-270,共10页
What does the impact of migration mean in a social context?This article aims to see migrants by taking their stories into account.Through the individual stories,the readers can see the way in which a bigger picture is... What does the impact of migration mean in a social context?This article aims to see migrants by taking their stories into account.Through the individual stories,the readers can see the way in which a bigger picture is emerged in terms of community,society and nation.By doing so,the authors want to show the way in which migrants integrate into a society,including both migrants having a residence permit and those who are undocumented,as these two groups of people do differ greatly.The cultural clash does mean the inner struggle and the outer struggle that a society has to confront with. 展开更多
关键词 SOCIETY MIGRATION trans-culture NARRATIVE IMPACT
在线阅读 下载PDF
Rotating regular black holes in AdS spacetime and its shadow for an arbitrary observer
4
作者 Balendra Pratap Singh Md Sabir Ali Sushant G Ghosh 《Communications in Theoretical Physics》 2025年第7期174-186,共13页
The photon region surrounding a black hole is crucial for distant observers to receive the emitted spectrum from its vicinity.This paper investigates the optical features of a regular spinning antide Sitter(AdS)black ... The photon region surrounding a black hole is crucial for distant observers to receive the emitted spectrum from its vicinity.This paper investigates the optical features of a regular spinning antide Sitter(AdS)black hole.These kinds of black holes hold deviation parameter k,and the cosmological constant A including their mass M and spin a.The cosmological parameter depends on the curvature radius by A=-3/l~2.We investigate the structure of geodesics for unstable circular orbits of photons as observed by an observer at specific Boyer-Lindquist coordinates(r_(O),v_(O))in the region between the outer and cosmological horizon,so-called the domain of outer communication.Our investigations include the analysis of three observables from its shadow plot:the black hole shadow radius(R_(s)),the distortion of the black hole(δ_(s)),and shadow area A.With the help of these observables,we calculate the angular diameter of the apparent size of the shadow.The shadows cast by spinning regular spacetimes are smaller compared to those produced by rotating black holes in both general relativity and regular spacetimes.We also calculate the rate at which energy is emitted from the black hole. 展开更多
关键词 regular black hole black hole shadow null geodesics and photon orbits
原文传递
Quantum-Resistant Cryptographic Primitives Using Modular Hash Learning Algorithms for Enhanced SCADA System Security
5
作者 Sunil K.Singh Sudhakar Kumar +5 位作者 Manraj Singh Savita Gupta Razaz Waheeb Attar Varsha Arya Ahmed Alhomoud Brij B.Gupta 《Computers, Materials & Continua》 2025年第8期3927-3941,共15页
As quantum computing continues to advance,traditional cryptographic methods are increasingly challenged,particularly when it comes to securing critical systems like Supervisory Control andData Acquisition(SCADA)system... As quantum computing continues to advance,traditional cryptographic methods are increasingly challenged,particularly when it comes to securing critical systems like Supervisory Control andData Acquisition(SCADA)systems.These systems are essential for monitoring and controlling industrial operations,making their security paramount.A key threat arises from Shor’s algorithm,a powerful quantum computing tool that can compromise current hash functions,leading to significant concerns about data integrity and confidentiality.To tackle these issues,this article introduces a novel Quantum-Resistant Hash Algorithm(QRHA)known as the Modular Hash Learning Algorithm(MHLA).This algorithm is meticulously crafted to withstand potential quantum attacks by incorporating advanced mathematical and algorithmic techniques,enhancing its overall security framework.Our research delves into the effectiveness ofMHLA in defending against both traditional and quantum-based threats,with a particular emphasis on its resilience to Shor’s algorithm.The findings from our study demonstrate that MHLA significantly enhances the security of SCADA systems in the context of quantum technology.By ensuring that sensitive data remains protected and confidential,MHLA not only fortifies individual systems but also contributes to the broader efforts of safeguarding industrial and infrastructure control systems against future quantumthreats.Our evaluation demonstrates that MHLA improves security by 38%against quantumattack simulations compared to traditional hash functionswhilemaintaining a computational efficiency ofO(m⋅n⋅k+v+n).The algorithm achieved a 98%success rate in detecting data tampering during integrity testing.These findings underline MHLA’s effectiveness in enhancing SCADA system security amidst evolving quantum technologies.This research represents a crucial step toward developing more secure cryptographic systems that can adapt to the rapidly changing technological landscape,ultimately ensuring the reliability and integrity of critical infrastructure in an era where quantum computing poses a growing risk. 展开更多
关键词 Hash functions post-quantum cryptography quantum-resistant hash functions network security supervisory control and data acquisition(SCADA)
在线阅读 下载PDF
Cardiovascular Sound Classification Using Neural Architectures and Deep Learning for Advancing Cardiac Wellness
6
作者 Deepak Mahto Sudhakar Kumar +6 位作者 Sunil KSingh Amit Chhabra Irfan Ahmad Khan Varsha Arya Wadee Alhalabi Brij B.Gupta Bassma Saleh Alsulami 《Computer Modeling in Engineering & Sciences》 2025年第6期3743-3767,共25页
Cardiovascular diseases(CVDs)remain one of the foremost causes of death globally;hence,the need for several must-have,advanced automated diagnostic solutions towards early detection and intervention.Traditional auscul... Cardiovascular diseases(CVDs)remain one of the foremost causes of death globally;hence,the need for several must-have,advanced automated diagnostic solutions towards early detection and intervention.Traditional auscultation of cardiovascular sounds is heavily reliant on clinical expertise and subject to high variability.To counter this limitation,this study proposes an AI-driven classification system for cardiovascular sounds whereby deep learning techniques are engaged to automate the detection of an abnormal heartbeat.We employ FastAI vision-learner-based convolutional neural networks(CNNs)that include ResNet,DenseNet,VGG,ConvNeXt,SqueezeNet,and AlexNet to classify heart sound recordings.Instead of raw waveform analysis,the proposed approach transforms preprocessed cardiovascular audio signals into spectrograms,which are suited for capturing temporal and frequency-wise patterns.The models are trained on the PASCAL Cardiovascular Challenge dataset while taking into consideration the recording variations,noise levels,and acoustic distortions.To demonstrate generalization,external validation using Google’s Audio set Heartbeat Sound dataset was performed using a dataset rich in cardiovascular sounds.Comparative analysis revealed that DenseNet-201,ConvNext Large,and ResNet-152 could deliver superior performance to the other architectures,achieving an accuracy of 81.50%,a precision of 85.50%,and an F1-score of 84.50%.In the process,we performed statistical significance testing,such as the Wilcoxon signed-rank test,to validate performance improvements over traditional classification methods.Beyond the technical contributions,the research underscores clinical integration,outlining a pathway in which the proposed system can augment conventional electronic stethoscopes and telemedicine platforms in the AI-assisted diagnostic workflows.We also discuss in detail issues of computational efficiency,model interpretability,and ethical considerations,particularly concerning algorithmic bias stemming from imbalanced datasets and the need for real-time processing in clinical settings.The study describes a scalable,automated system combining deep learning,feature extraction using spectrograms,and external validation that can assist healthcare providers in the early and accurate detection of cardiovascular disease.AI-driven solutions can be viable in improving access,reducing delays in diagnosis,and ultimately even the continued global burden of heart disease. 展开更多
关键词 Healthy society cardiovascular system SPECTROGRAM FastAI audio signals computer vision neural network
在线阅读 下载PDF
Enhancing Healthcare Data Privacy in Cloud IoT Networks Using Anomaly Detection and Optimization with Explainable AI (ExAI)
7
作者 Jitendra Kumar Samriya Virendra Singh +4 位作者 Gourav Bathla Meena Malik Varsha Arya Wadee Alhalabi Brij B.Gupta 《Computers, Materials & Continua》 2025年第8期3893-3910,共18页
The integration of the Internet of Things(IoT)into healthcare systems improves patient care,boosts operational efficiency,and contributes to cost-effective healthcare delivery.However,overcoming several associated cha... The integration of the Internet of Things(IoT)into healthcare systems improves patient care,boosts operational efficiency,and contributes to cost-effective healthcare delivery.However,overcoming several associated challenges,such as data security,interoperability,and ethical concerns,is crucial to realizing the full potential of IoT in healthcare.Real-time anomaly detection plays a key role in protecting patient data and maintaining device integrity amidst the additional security risks posed by interconnected systems.In this context,this paper presents a novelmethod for healthcare data privacy analysis.The technique is based on the identification of anomalies in cloud-based Internet of Things(IoT)networks,and it is optimized using explainable artificial intelligence.For anomaly detection,the Radial Boltzmann Gaussian Temporal Fuzzy Network(RBGTFN)is used in the process of doing information privacy analysis for healthcare data.Remora Colony SwarmOptimization is then used to carry out the optimization of the network.The performance of the model in identifying anomalies across a variety of healthcare data is evaluated by an experimental study.This evaluation suggested that themodel measures the accuracy,precision,latency,Quality of Service(QoS),and scalability of themodel.A remarkable 95%precision,93%latency,89%quality of service,98%detection accuracy,and 96%scalability were obtained by the suggested model,as shown by the subsequent findings. 展开更多
关键词 Healthcare data privacy analysis anomaly detection cloud IoT network explainable artificial intelligence temporal fuzzy network
在线阅读 下载PDF
Mechanical performance of key components in floating photovoltaic systems:technological advances and application prospects
8
作者 Kai Feng Shuaiqi Li +8 位作者 Lin Fu Yingjiu Zhao Bin Zhang Sombel Diaham Chatchai Putson Fouad Belhora Abdelowahed Hajjaji Yahia Boughaleb Jiawei Zhang 《Global Energy Interconnection》 2025年第5期719-731,共13页
Floating photovoltaic(FPV)technology is emerging as a highly promising approach to accelerate decarbonization of the global economy,due to its higher power generation efficiency and lower land occupation.With the rapi... Floating photovoltaic(FPV)technology is emerging as a highly promising approach to accelerate decarbonization of the global economy,due to its higher power generation efficiency and lower land occupation.With the rapid development of FPV technology,the mechanical performance degradation of key components caused by the harsh marine environment has become a pressing issue,as it significantly contributes to failure behavior observed in FPV systems.A comprehensive compilation of the mechanical performance of key components in FPV systems is also currently unavailable.Here,the mechanical behavior of each structural component in FPV systems under harsh marine environments is systematically reviewed.It further emphasizes the synergistic effects of mechanical performance degradation among different components on the overall system.The drop-off rate(v)of normalized elongation at break(EAB)of polymer under the synergistic effect of various environmental factors increases from 7.5×10^(−4)h^(−1)to 21.8×10^(−4)h^(−1)compared with the single environmental stress.Moreover,the development of novel materials and innovative mechanical structures applied in FPV systems to enhance mechanical performance is discussed.The novel flexible PV modules applied in FPV systems minimize the loads acting on the mooring lines by 80%and increase power generation by 5%.Notably,this paper provides a theoretical foundation for developing standards of FPV systems,especially the establishment of standards related to the synergistic effects of the mechanical performance degradation of different key components on FPV systems. 展开更多
关键词 Floating photovoltaic systems Harsh marine environments Synergistic aging effects Mechanical performance Novel materials
在线阅读 下载PDF
The KREEP-rich circum-Lalande region:A candidate landing area for future lunar crewed missions
9
作者 Sheng Gou ZongYu Yue +9 位作者 YangTing Lin KaiChang Di YuYang He HengCi Tian Patrick CPinet ZhanChuan Cai Roberto Bugiolacchi HongLei Lin Sen Hu Wei Yang 《Earth and Planetary Physics》 2025年第6期1135-1146,共12页
The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP... The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.Both sites are situated on the Th-(a critical marker of KREEP)and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium,respectively.Their geolocations at the low latitude on the lunar nearside,the flat surface,and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication.The astronauts could perform many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather a variety of samples,such as Lalande ejecta,basalts,Copernicus ejecta,and regolith.The returned samples are valuable to explore the speculated urKREEP,to reveal the relationship between heat-producing elements and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith. 展开更多
关键词 primordial KREEP Th-rich Lalande ejecta landing sites lunar crewed missions extravehicular activities
在线阅读 下载PDF
Recurrent spontaneous miscarriages from sperm after ABVD chemotherapy in a patient with Hodgkin's lymphoma: sperm DNA and methylation profiling
10
作者 Gwendoline Lecuyer Antoine D Rolland +11 位作者 Anne-Sophie Neyroud Bertrand Evrard Nathan Alary Clemence Genthon Nathalie Dejucq-Rainsford Célia Rave Jessika Moreau Nathalie Moinard Mohamed Hadi Mohamed Abdelhamid Christophe Klopp Louis Bujan Frédéric Chalmel 《Asian Journal of Andrology》 2025年第5期598-610,共13页
Lymphomas represent one of the most common malignant diseases in young men and an important issue is how treatments will affect their reproductive health.It has been hypothesized that chemotherapies,similarly to envir... Lymphomas represent one of the most common malignant diseases in young men and an important issue is how treatments will affect their reproductive health.It has been hypothesized that chemotherapies,similarly to environmental chemicals,may alter the spermatogenic epigenome.Here,we report the genomic and epigenomic profiling of the sperm DNA from a 31-year-old Hodgkin lymphoma patient who faced recurrent spontaneous miscarriages in his couple 11-26 months after receiving chemotherapy with adriamycin,bleomycin,vinblastine,and dacarbazine(ABVD).In order to capture the potential deleterious impact of the ABVD treatment on mutational and methylation changes,we compared sperm DNA before and 26 months after chemotherapy with whole-genome sequencing(WGS)and reduced representation bisulfite sequencing(RRBS).The WGS analysis identified 403 variants following ABVD treatment,including 28 linked to genes crucial for embryogenesis.However,none were found in coding regions,indicating no impact of chemotherapy on protein function.The RRBS analysis identified 99high-quality differentially methylated regions(hqDMRs)for which methylation status changed upon chemotherapy.Those hqDRMs were associated with 87 differentially methylated genes,among which 14 are known to be important or expressed during embryo development.While no variants were detected in coding regions,promoter regions of several genes potentially important for embryo development contained variants or displayed an altered methylated status.These might in turn modify the corresponding gene expression and thus affect their function during key stages of embryogenesis,leading to potential developmental disorders or miscarriages. 展开更多
关键词 CHEMOTHERAPY embryo loss METHYLATION MISCARRIAGE sperm DNA whole-genome sequencing
原文传递
双钨极TIG电弧压强分布及其与等离子体喷射的关系 被引量:5
11
作者 李桓 王飞 +3 位作者 Y Cressault Ph Teulet 杨珂 于福盛 《电焊机》 2017年第7期1-5,共5页
建立一个三维的统一的双钨极TIG焊模型,利用磁流体动力学理论对双钨极、电弧、阳极三个区域进行统一求解,获到双钨极电弧的压强分布,探究等离子体喷射与对电弧压强的关系。研究发现,双钨极TIG在钨极下方、阳极上方以及两束等离子体流交... 建立一个三维的统一的双钨极TIG焊模型,利用磁流体动力学理论对双钨极、电弧、阳极三个区域进行统一求解,获到双钨极电弧的压强分布,探究等离子体喷射与对电弧压强的关系。研究发现,双钨极TIG在钨极下方、阳极上方以及两束等离子体流交汇处存在较大的电弧压强,这些高压区的形成与等离子体喷射存在因果关系。计算发现,双钨极TIG焊在阳极表面上的最大压强远小于单钨极TIG焊的,这为双钨极TIG焊的应用提供了一些理论基础。 展开更多
关键词 双钨极TIG 模拟 电弧压强 等离子体喷射
在线阅读 下载PDF
氩等离子体紫外光A和B辐射属性计算 被引量:1
12
作者 王飞 李桓 +2 位作者 Cressault Yann Teulet Philippe 杨珂 《焊接学报》 EI CAS CSCD 北大核心 2019年第7期12-15,I0002,共5页
焊接等离子体释放的紫外光A(315~400nm)和紫外光B(280~315nm)是皮肤癌的重要诱因.基于净辐射系数的概念,考虑了连续谱(复合辐射和轫致辐射)和线谱等辐射机制,计算了氩等离子在常压、5000~25000K内的紫外光A,B的辐射属性.结果表明,随着... 焊接等离子体释放的紫外光A(315~400nm)和紫外光B(280~315nm)是皮肤癌的重要诱因.基于净辐射系数的概念,考虑了连续谱(复合辐射和轫致辐射)和线谱等辐射机制,计算了氩等离子在常压、5000~25000K内的紫外光A,B的辐射属性.结果表明,随着等离子体半径Rp增加,全谱辐射发生强烈的自吸收效应,而紫外光A,B基本无自吸收;当Rp=1mm时,它们在总谱辐射(35~4500nm)的最大的占比分别为6.0%,1.9%,在非真空紫外辐射(200~4500nm)的最大的占比为36.3%和5%.为钨极氩弧的紫外光危害性研究提供了理论依据. 展开更多
关键词 紫外光 辐射 焊接电弧 皮肤癌 净辐射系数
在线阅读 下载PDF
UPS应用与供电系统设计技术探讨 被引量:1
13
作者 王力坚 李成章 +2 位作者 周瑶强 韩林 江伟石 《电气应用》 北大核心 2009年第23期18-19,共2页
UPS作为重要的备用电源设备,已经在金融、通信等传统领域的数据中心得到了广泛的应用,随着大功率UPS制造技术的不断突破,UPS正逐步大量应用于制造业、工业等领域的自动化生产线和DCS、PLC系统中。UPS供电系统接地设计、UPS供电方式及绿... UPS作为重要的备用电源设备,已经在金融、通信等传统领域的数据中心得到了广泛的应用,随着大功率UPS制造技术的不断突破,UPS正逐步大量应用于制造业、工业等领域的自动化生产线和DCS、PLC系统中。UPS供电系统接地设计、UPS供电方式及绿色性能等受到相关技术人员的关注。在UPS供电系统接地设计中,如何处理零地电压问题,石化行业UPS应用中,针对不同的DCS系统接地方式,如何选择合理、适用的UPS接地方式,以及UPS供电系统与备用发电机如何实现容量匹配,本期栏目将继续邀请UPS用户专家和UPS厂商技术人员针对上述话题以及UPS选型等问题进行讨论、交流,同时欢迎感兴趣的读者能够积极参与。 展开更多
关键词 UPS供电系统 系统设计技术 接地方式 DCS 应用 制造商 工程师 伙伴
原文传递
植入碳纤维蜂窝夹芯结构的光纤光栅热载荷响应光谱研究 被引量:1
14
作者 马驰 曾捷 +4 位作者 张景川 龚晓静 张益昕 冯翔宇 周林 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2017年第9期2927-2932,共6页
针对航天领域复合材料结构在空间服役环境的热响应监测需求,研究了一种热载荷作用下基于光纤Bragg光栅(FBG)反射光谱特征分析的碳纤维蜂窝夹芯结构监测方法。将光纤Bragg光栅传感器分别植入碳纤维蜂窝夹芯结构的不同铺层,通过监测不同... 针对航天领域复合材料结构在空间服役环境的热响应监测需求,研究了一种热载荷作用下基于光纤Bragg光栅(FBG)反射光谱特征分析的碳纤维蜂窝夹芯结构监测方法。将光纤Bragg光栅传感器分别植入碳纤维蜂窝夹芯结构的不同铺层,通过监测不同热载荷下各铺层位置的光纤光栅反射光谱,得到碳纤维蜂窝夹芯结构相关铺层位置热应变特征。研究表明,碳纤维蜂窝夹芯结构不同材料铺层的热应变特征存在一定差异。植入外蒙皮表面与玻璃布之间的光纤光栅反射光谱随着温度升高,中心波长向长波方向漂移,且波形未出现明显改变。埋植于外蒙皮第二、三层碳纤维织物预浸料之间的光栅反射光谱随着温度降低逐渐出现旁瓣、多峰等啁啾效应,其主峰与右侧次峰中心波长均向短波方向逐渐漂移,主峰峰值幅度变化较小,温度灵敏度约为5.56×10^(-3) dBm·℃^(-1),而右侧次峰幅度显著增大,温度灵敏度约为40.32×10^(-3)dBm·℃^(-1);埋植于内蒙皮和蜂窝芯子之间的光栅反射光谱随着温度降低,其半波峰带宽逐渐增大,变化率约为3.19pm·℃^(-1),且出现显著多峰趋势,这是由于层间热应力分布不均匀所形成。在-70^+60℃温度范围,各植入层热应变均随温度升高而增大,且变化趋势相接近,而在+60^+120℃温度范围内,各植入层热应变变化趋势呈现显著差异。这些特性能够为后继空间环境复合材料航天器结构状态在轨监测提供有益帮助。 展开更多
关键词 碳纤维蜂窝夹芯结构 光纤光栅 反射光谱 热应变
在线阅读 下载PDF
大功率UPS工频机和高频机性能对比 被引量:3
15
作者 温顺理 杨波 《电信网技术》 2009年第4期82-85,共4页
1工频机和高频机的定义和原理分析 UPS通常分为工频机和高频机两种。工频机由可控硅SCR整流器,IGBT逆变器,旁路和工频升压隔离变压器组成。因其整流器和变压器工作频率均为工频50Hz,顾名思义叫工频UPS。典型的工频UPS拓扑参见图1。
关键词 UPS 高频机 工频 性能对比 大功率 IGBT逆变器 隔离变压器 工作频率
在线阅读 下载PDF
UPS及EPS的应用技术与发展趋势 被引量:3
16
作者 张乃国 《电源技术应用》 2004年第12期759-768,共10页
就当前一体化机房供电系统、UPS 与 EPS 的应用特点及发展趋势进行了阐述。
关键词 UPS EPS(应急电源) 应用技术 发展趋势
在线阅读 下载PDF
UPS“1+1”并机冗余系统和单机双总线系统方案对比 被引量:2
17
作者 温顺理 《电源技术应用》 2005年第4期i003-i004,共2页
"1+1"并机冗余方案是实际使用较多的一种UPS供电方案,但该方案并不是十全十美,通过"1+1"并机系统扣单机双母线系统方案对比,推荐客户在核心设备上使用可靠性更高的单机双总线方案。
关键词 UPS 不间断电源 可靠性 “1+1”并机冗余系统 单机双总线系统 供电系统 计算机
在线阅读 下载PDF
大功率UPS输入谐波电流抑制四种方案比较 被引量:1
18
作者 吴健 《教育信息化》 CSSCI 2005年第12S期79-79,共1页
对大功率UPS来说,如果UPS整流装置为三相全控桥6脉整流器,由整流装置产生的谐波占所有谐波的近25—33%,对电网的危害较大,谐波有可造成配电线缆、变压器发热,降低通话质量,空气开关误动作,发电机喘振等不良后果;谐波按电流相... 对大功率UPS来说,如果UPS整流装置为三相全控桥6脉整流器,由整流装置产生的谐波占所有谐波的近25—33%,对电网的危害较大,谐波有可造成配电线缆、变压器发热,降低通话质量,空气开关误动作,发电机喘振等不良后果;谐波按电流相序分为+序(3k+1次,k为0和正整数)、一序(3k+2次,k为0和正整数)、0序(3k次.k为正整数),+序电流使损耗加重,一序电流使电机反转、发热.0序电流使中线电流异常增大。 展开更多
关键词 UPS 电流 谐波 方案比较 功率 正整数 通话质量 发电机 整流器 变压器
在线阅读 下载PDF
大功率UPS 6脉冲与12脉冲晶闸管整流器原理与区别 被引量:1
19
作者 温顺理 《电源技术应用》 2007年第2期69-69,共1页
(接上期) 而单独的12脉整流器也可达到10%左右的电流谐波指标,但是没有大电容的LC电路,避免了与发电机的励磁正反馈效应。
关键词 整流器 UPS 大功率 原理 脉冲 电流谐波 LC电路 反馈效应
在线阅读 下载PDF
大功率UPS 6脉冲与12脉冲晶闸管整流器原理与区别 被引量:1
20
作者 温顺理 《电源技术应用》 2007年第1期66-67,共2页
1理论推导 1.1 6脉冲整流器原理 6脉冲指以6个可控硅(晶闸管)组成的全桥整流,由于有6个开关脉冲对6个可控硅分别控制,所以叫6脉冲整流。
关键词 晶闸管整流器 脉冲整流器 艾默生网络能源有限公司 UPS产品 原理 大功率 开关脉冲 可控硅
在线阅读 下载PDF
上一页 1 2 45 下一页 到第
使用帮助 返回顶部