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Near infrared emissions from both high efficient quantum cutting (173%) and nearly-pure-color upconversion in NaY(WO_(4))_(2):Er^(3+)/Yb^(3+) with thermal management capability for silicon-based solar cells

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Light(Science & Applications) 2024年第1期13卷 113-126页

作者： Duan Gao Baojiu Chen xuezhu sha Yuhang Zhang Xin Chen Li Wang Xizhen Zhang Jinsu Zhang Yongze Cao Yichao Wang Lei Li Xiangping Li Sai Xu Hongquan Yu Lihong Cheng School of Science Dalian Maritime UniversityDalian 116026 LiaoningChina

Raising photoelectric conversion efficiency and enhancing heat management are two critical concerns for siliconbased solar *** this work,efficient Yb^(3+) infrared emissions from both quantum cutting and upconversion were demonstrated by adjusting Er^(3+) and Yb^(3+) concentrations,and thermo-manage-applicable temperature sensing based on the luminescence intensity ratio of two super-low thermal quenching levels was discovered in an Er^(3+)/Yb^(3+) codoped tungstate *** quantum cutting mechanism was clearly decrypted as a two-step energy transfer process from Er^(3+) to Yb^(3+).The two-step energy transfer efficiencies,the radiative and nonradiative transition rates of all interested 4 f levels of Er^(3+) in NaY(WO_(4))_(2) were confirmed in the framework of Föster-Dexter theory,Judd-Ofelt theory,and energy gap law,and based on these obtained efficiencies and rates the quantum cutting efficiency was furthermore determined to be as high as 173%in NaY(WO_(4))_(2):5 mol%Er^(3+)/50 mol%Yb^(3+) *** and nearly pure infrared upconversion emission of Yb3+under 1550 nm excitation was achieved in Er^(3+)/Yb^(3+)co-doped NaY(WO_(4))_(2) by adjusting Yb^(3+) doping *** Yb^(3+) induced infrared upconversion emission enhancement was attributed to the efficient energy transfer ^(4)I_(11/2)(Er^(3+))+^(2)F_(7/2)(Yb^(3+))→^(4)I_(15/2)(Er^(3+))+^(2)F_(5/2)(Yb^(3+))and large nonradiative relaxation rate of ^(4)I_(9/2).Analysis on the temperature sensing indicated that the NaY(WO_(4))_(2):Er^(3+)/Yb^(3+)serves well the solar cells as thermos-managing ***,it was confirmed that the fluorescence thermal quenching of ^(2)H_(11/2)/^(4)S_(3/2) was caused by the nonradiative relaxation of ^(4)S_(3/2).All the obtained results suggest that NaY(WO_(4))_(2):Er^(3+)/Yb^(3+) is an excellent material for silicon-based solar cells to improve photoelectric conversion efficiency and thermal management.

关键词： quantum thermal relaxation

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Stability Prediction in Smart Grid Using PSO Optimized XGBoost Algorithm with Dynamic Inertia Weight Updation

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 909-931页

作者： Adel Binbusayyis Mohemmed sha Department of Software Engineering College of Computer Engineering and Sciences in Al-Kharj Prince Sattam Bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia

Prediction of stability in SG(Smart Grid)is essential in maintaining consistency and reliability of power supply in grid *** the fluctuations in power generation and consumption patterns of smart cities assists in effectively managing continuous power supply in the *** also possesses a better impact on averting overloading and permitting effective energy *** though many traditional techniques have predicted the consumption rate for preserving stability,enhancement is required in prediction measures with minimized *** overcome the complications in existing studies,this paper intends to predict stability from the smart grid stability prediction dataset using machine learning *** accomplish this,pre-processing is performed initially to handle missing values since it develops biased models when missing values are mishandled and performs feature scaling to normalize independent data ***,the pre-processed data are taken for training and *** that,the regression process is performed using Modified PSO(Particle Swarm Optimization)optimized XGBoost Technique with dynamic inertia weight update,which analyses variables like gamma(G),reaction time(tau1–tau4),and power balance(p1–p4)for providing effective future stability in *** PSO attains optimal solution by adjusting position through dynamic inertial weights,it is integrated with XGBoost due to its scalability and faster computational speed *** hyperparameters of XGBoost are fine-tuned in the training process for achieving promising outcomes on *** results are measured through evaluation metrics such as MSE(Mean Square Error)of 0.011312781,MAE(Mean Absolute Error)of 0.008596322,and RMSE(Root Mean Square Error)of 0.010636156 and MAPE(Mean Absolute Percentage Error)value of 0.0052 which determine the efficacy of the system.

关键词： Smart Grid machine learning particle swarm optimization XGBoost dynamic inertia weight update

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NaGd(MoO_(4))_(2)∶Tb^(3+)荧光粉的温度及浓度依赖发光与荧光动力学温度传感

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发光学报 2023年第10期44卷 1770-1778页

作者：白海斌陈昕沙雪竹高端张映辉张翔清陈宝玖大连海事大学理学院辽宁大连116026

采用高温固相法制备了不同Tb^(3+)掺杂浓度的NaGd(MoO_(4))_(2)∶Tb^(3+)荧光粉,XRD结果证实所制得样品为纯相。利用荧光光谱测量对该荧光粉的发光浓度猝灭进行了分析,证明荧光浓度猝灭是由Tb^(3+)离子间的交换相互作用所导致,并符合浓... 详细信息

采用高温固相法制备了不同Tb^(3+)掺杂浓度的NaGd(MoO_(4))_(2)∶Tb^(3+)荧光粉,XRD结果证实所制得样品为纯相。利用荧光光谱测量对该荧光粉的发光浓度猝灭进行了分析,证明荧光浓度猝灭是由Tb^(3+)离子间的交换相互作用所导致,并符合浓度猝灭的Ozawa模型。采用Auzel提出的自产生猝灭模型对Tb^(3+)的5D4能级荧光动力学进行了分析,结果表明该模型能够很好地解释荧光寿命对浓度的依赖关系。研究了Tb^(3+)的^(5)D_(4)能级的发光强度和荧光寿命对样品温度的依赖关系,提出了利用荧光寿命进行温度传感的方法,并对温度传感的绝对和相对灵敏度进行了分析。

关键词：高温固相法浓度猝灭荧光衰减热猝灭温度传感

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MXene Hybridized Polymer with Enhanced Electromagnetic Energy Harvest for Sensitized Microwave Actuation and Self‑Powered Motion Sensing

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Nano-Micro Letters 2025年第3期17卷 265-279页

作者： Yu‑Ze Wang Yu‑Chang Wang Ting‑Ting Liu Quan‑Liang Zhao Chen‑sha Li Mao‑Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of Materials Science and Engineering Peking UniversityBeijing 100871People’s Republic of China School of Mechanical and Material Engineering North China University of TechnologyBeijing 100144People’s Republic of China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080People’s Republic of China

Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.

关键词： Microwave absorption Electromagnetic response Energy harvest Self-sensing Soft actuator

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Facile synthesis of the dodecahydridododecaborate (B12H122-) from borane Lewis base adducts

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Science China Chemistry 2025年

作者： Yi Jing Xin-Ran Liu Xing-Hua Wang Hui Han sha-sha Liang Xi-Meng Chen Dong-Hui Wei Lai-Sheng Wang Xue-Nian Chen College of Chemistry Zhengzhou University School of Chemistry and Chemical Engineering Henan Key Laboratory of Boron Chemistry and Advanced MaterialsHenan Normal University Department of Chemistry Brown University

Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy,chemistry,medicine,and materials science because of their unique physical and chemical *** efforts have been made in the past decades to find more effective synthetic methods for this important class of boron ***,existing synthetic methods suffer from low efficiency and low ***,we report a facile one-pot synthesis of[（CH3）3S]2B12H12with moderate yields at mild *** mechanisms for the multi-step chemoselective synthesis of B12H122-without other by-products are elucidated based on theoretical results and our previous *** Lewis base used in B–H bond condensation reaction,which acts as a hydrogen or to balance the newly generated polyhedral borane charges,is proposed and studied in *** current study has led to a more effective and selective synthetic method for B12H122-and has also implicated the syntheses of other new polyhedral boranes.

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数媒时代焦虑、抑郁与社会比较的关系

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心理科学进展 2025年第1期33卷 92-106,I0001-I0007页

作者：赵立白莎首都经济贸易大学工商管理学院北京100070

社会焦虑和抑郁现象日益严重。为理解与探索数媒时代焦虑、抑郁的引致因素及应对策略,研究采用系统性文献综述方法,基于情感事件理论和社会比较理论构建框架,梳理了社会比较的不同亚型与焦虑、抑郁的关系以及网络媒体环境的权变作用。... 详细信息

社会焦虑和抑郁现象日益严重。为理解与探索数媒时代焦虑、抑郁的引致因素及应对策略,研究采用系统性文献综述方法,基于情感事件理论和社会比较理论构建框架,梳理了社会比较的不同亚型与焦虑、抑郁的关系以及网络媒体环境的权变作用。研究发现,消极社会比较(传统上行比较和下行同化比较)可能会引发焦虑和抑郁,社交网络平台对此负面影响具有催化作用;而情绪比较和下行对比比较可以缓解焦虑和抑郁,网络健康社区促进了情绪比较的积极作用的发挥。研究推进了社会比较理论在情绪情感领域的应用,确定了焦虑、抑郁与网络健康社区可供性的关联,也为网络社区服务、运营和设计的原则提供参考和借鉴以帮助个体应对心理健康问题。研究还指出焦虑、抑郁和社会比较关系后续研究的可能路径和方向。

关键词：社会比较焦虑抑郁社交网络平台网络健康社区

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代谢工程改造大肠杆菌合成甲萘醌-7

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食品与发酵工业 2025年第1期51卷 1-10页

作者：何雨锴曾伟主徐沙江南大学生物工程学院江苏无锡214122 江南大学粮食发酵工艺与技术国家工程实验室江苏无锡214122 江南大学未来食品科学中心江苏无锡214122

甲萘醌-7(menaquinone-7,MK-7),作为维生素K2亚型之一,具有治疗骨质疏松,保护心血管健康等作用。常见MK-7生产主要由纳豆等食品发酵而来,但存在产量低,提取复杂等问题,而枯草芽孢杆菌作为MK-7常见生产菌株,也面临发酵周期长,发酵产量低... 详细信息

甲萘醌-7(menaquinone-7,MK-7),作为维生素K2亚型之一,具有治疗骨质疏松,保护心血管健康等作用。常见MK-7生产主要由纳豆等食品发酵而来,但存在产量低,提取复杂等问题,而枯草芽孢杆菌作为MK-7常见生产菌株,也面临发酵周期长,发酵产量低的问题。该研究对一株引入甲羟戊酸途径的大肠杆菌进行改造,首先利用DLKcat模型比较筛选出4个关键酶,包括七聚异戊二烯焦磷酸合酶BtHepS\BtHepT、1,4-二羟基-2-萘甲酸七烯基转移酶MnMenA、甲萘醌生物合成C-甲基转移酶NtMenG,将其进行表达优化,构建了大肠杆菌内源合成MK-7途径。随后,整合表达异戊烯基焦磷酸异构酶EcIdi提升前体供应,再对得到的菌株进行补料分批发酵条件优化,包括延迟诱导时间,提升溶氧量至60,MK-7产量达到929.58 mg/L,但出现1217.58 mg/L的去甲基甲萘醌-7(DMK-7)大量堆积的现象。进一步筛选了不同来源的MenG降低DMK-7的堆积,发现Bacillus subtilis 168来源的MenG可以较好地降低DMK-7堆积。最终,在5 L发酵罐上MK-7的产量达到1090.45 mg/L,DMK-7降低至231.14 mg/L。该研究结果对应用大肠杆菌生产MK-7具有一定的指导意义。

关键词：甲萘醌-7 大肠杆菌 DLKcat 去甲基甲萘醌-7 发酵优化

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Atomically precise nickel-sulfur clusters for efficient electrochemical 2,5-hydroxymethylfurfural oxidation

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Nano Research 2025年第1期18卷 140-148页

作者： Fen Wang Lu-Yu Liu sha-sha Cui Ting-Ting Li Xiao-Meng Yang Zhijuan Liu Yanyong Wang Henan Key Laboratory of Crystalline Molecular Functional Materials Henan International Joint Laboratory of Tumor Theranostical Cluster MaterialsGreen Catalysis Centerand College of ChemistryZhengzhou UniversityZhengzhou 450001China State Key Laboratory of Chem/Bio-sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

Nickel sulfide exhibits excellent catalytic activity in the electrochemical 2,5-hydroxymethylfurfural oxidation reaction(HMFOR).However,due to the polydispersity of nanoparticles,it is difficult to establish a clear structure-activity relationship at the atomic *** this work,we have successfully synthesized atomically precise Ni_(6)(PET)_(12)and Ni_(4)(PET)_(8)clusters(PET:2-phenylethanethiol)for ***^(2+)and S_(2)-with atomic ratio of 1:2 was mainly existed in Ni_(6)(PET)_(12)and Ni_(4)(PET)_(8)to form Ni-S *** electrochemical test results have suggested both Ni_(6)(PET)_(12)and Ni_(4)(PET)_(8)displayed outstanding electrocatalytic ability for *** Ni_(6)(PET)_(12)exhibited better electrocatalytic ability than Ni_(4)(PET)_(8)with higher current density,lower overpotential and faster reaction *** superior electrochemical ability of Ni_(6)(PET)_(12)may be due to the enhanced adsorption towards HMF molecule with strong interaction towards hydroxyl group and furan ***,it found that the Ni^(2+)species in Ni_(6)(PET)_(12)could rapidly oxidized into Ni^(3+)species,which could spontaneously capture electron and proton from HMF for *** theoretical calculation demonstrated that the Ni_(6)(PET)_(12)process lower free energy barrier than Ni_(4)(PET)_(8)to display excellent electrocatalytic *** work is of great significance for designing efficient electrocatalysts for HMFOR.

关键词： atomically precise nickel nanoclusters 2 5-hydroxymethylfurfural electro-oxidation Ni3+species

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从殖民主义视阈解读列奥波尔德·赛达·桑戈尔双重身份

语言与文化研究

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语言与文化研究 2025年第1期33卷 250-253页

作者：胡莎云南大学昆明650500

列奥波尔德·赛达·桑戈尔是非洲塞内加尔的开国总统同时兼任法国制宪委员会议员。作为塞内加尔国民,桑戈尔始终与法国关系亲密,在塞内加尔推行法国文化。作为一名法国公民,桑戈尔提出黑人性精神,推动西非人民的独立运动,脱离法国殖民... 详细信息

列奥波尔德·赛达·桑戈尔是非洲塞内加尔的开国总统同时兼任法国制宪委员会议员。作为塞内加尔国民,桑戈尔始终与法国关系亲密,在塞内加尔推行法国文化。作为一名法国公民,桑戈尔提出黑人性精神,推动西非人民的独立运动,脱离法国殖民。桑戈尔的双重国籍身份,支持塞内加尔的独立以及促进法国对塞同化矛盾行径,使得外界对桑戈尔的评价褒贬不一。本文将从列奥波尔德·赛达·桑戈尔的生平,殖民时期的同化政策对桑戈尔双重身份的解构与去殖民化对桑戈尔双重身份的重构三个角度来解读桑戈尔的双重身份,让更多的人能从更客观的角度来重新认识桑戈尔。

关键词：桑戈尔双重身份殖民主义同化政策去殖民化

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再生碳纤维对机场跑道导电混凝土性能的影响

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合成纤维 2025年第1期54卷 78-81页

作者：沙东周口市住房保障和房地产业发展中心河南周口466000

对废旧碳纤维进行机械处理回收,用其制备了一种环保型导电混凝土,并通过抗压强度、抗折强度、电热试验以及融冰融雪能力试验对其进行性能评价。结果表明:当再生碳纤维体积分数为3.0%时,导电混凝土的抗压强度与抗折强度均达到峰值,7、28 ... 详细信息

对废旧碳纤维进行机械处理回收,用其制备了一种环保型导电混凝土,并通过抗压强度、抗折强度、电热试验以及融冰融雪能力试验对其进行性能评价。结果表明:当再生碳纤维体积分数为3.0%时,导电混凝土的抗压强度与抗折强度均达到峰值,7、28 d抗压强度分别为33.72、42.57 MPa;7、28 d抗折强度分别为5.03、6.38 MPa;随着再生碳纤维体积分数的不断增加,导电混凝土的电热效率与融冰融雪能力快速提高,在模拟融冰融雪试验中,120 min后温度升高到1.9℃,温升速率达0.12K/min。

关键词：再生碳纤维机场路面导电混凝土

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