期刊文献+
共找到10,238篇文章
< 1 2 250 >
每页显示 20 50 100
Application of artificial neural networks in optimal tuning of tuned mass dampers implemented in high-rise buildings subjected to wind load 被引量:8
1
作者 Meysam Ramezani Akbar Bathaei Amir K.Ghorbani-Tanha 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第4期903-915,共13页
High-rise buildings are usually considered as flexible structures with low inherent damping. Therefore, these kinds of buildings are susceptible to wind-induced vibration. Tuned Mass Damper(TMD) can be used as an ef... High-rise buildings are usually considered as flexible structures with low inherent damping. Therefore, these kinds of buildings are susceptible to wind-induced vibration. Tuned Mass Damper(TMD) can be used as an effective device to mitigate excessive vibrations. In this study, Artificial Neural Networks is used to find optimal mechanical properties of TMD for high-rise buildings subjected to wind load. The patterns obtained from structural analysis of different multi degree of freedom(MDF) systems are used for training neural networks. In order to obtain these patterns, structural models of some systems with 10 to 80 degrees-of-freedoms are built in MATLAB/SIMULINK program. Finally, the optimal properties of TMD are determined based on the objective of maximum displacement response reduction. The Auto-Regressive model is used to simulate the wind load. In this way, the uncertainties related to wind loading can be taken into account in neural network’s outputs. After training the neural network, it becomes possible to set the frequency and TMD mass ratio as inputs and get the optimal TMD frequency and damping ratio as outputs. As a case study, a benchmark 76-story office building is considered and the presented procedure is used to obtain optimal characteristics of the TMD for the building. 展开更多
关键词 artificial neural networks tuned mass damper wind load auto-regressive model optimal frequency anddamping
下载PDF
Analysis of the independent-and interactive-photo-thermal effects on soybean flowering 被引量:4
2
作者 WU Ting-ting LI Jin-yu +5 位作者 WU Cun-xiang SUN Shi MAO Ting-ting JIANG Bing-jun HOU Wen-sheng HAN Tian-fu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第4期622-632,共11页
Soybean(Glycine max(L.) Merr.) is a typical short-day and warm season plant, and the interval between emergence and flowering has long been known to be regulated by environmental factors, primarily photoperiod and... Soybean(Glycine max(L.) Merr.) is a typical short-day and warm season plant, and the interval between emergence and flowering has long been known to be regulated by environmental factors, primarily photoperiod and temperature. While the effects of photoperiod and temperature on soybean flowering have been extensively studied, a dissection of the component photo-thermal effects has not been documented for Chinese germplasm. Our objective of the current study was to evaluate the independent- and interactive-photo-thermal responses of 71 cultivars from 6 ecotypes spanning the soybean production regions in China. These cultivars were subjected in pot experiments to different temperature regimes by planting in spring(low temperature(LT)) and summer(high temperature(HT)), and integrating with short day(SD, 12 h), natural day(ND, variable day-length), and long day(LD, 16 h) treatments over two years. The duration of the vegetative phase from emergence to first bloom(R1) was recorded, and the photo-thermal response was calculated. The outcome of this characterization led to the following conclusions:(1) There were significant differences in photo-thermal response among the different ecotypes. High-latitude ecotypes were less sensitive to the independent- and interactive-photo-thermal effects than low-latitude ecotypes; and(2) there was an interaction between photoperiod and temperature, with the effect of photoperiod on thermal sensitivity being greater under the LD than the SD condition, and with the effect of temperature on photoperiodic sensitivity being greater under the LT than the HT condition. The strengths and limitations of this study are discussed in terms of implications for current knowledge and future research directions. The study provides better understanding of photo-thermal effects on flowering in soybean genotypes from different ecotypes throughout China and of the implications for their adaptation more broadly. 展开更多
关键词 SOYBEAN FLOWERING PHOTOPERIOD temperature photo-thermal response
下载PDF
A review on photo-thermal catalytic conversion of carbon dioxide 被引量:8
3
作者 Ee Teng Kho Tze Hao Tan +3 位作者 Emma Lovell Roong Jien Wong Jason Scott Rose Amal 《Green Energy & Environment》 SCIE 2017年第3期204-217,共14页
The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a signifi... The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed. 展开更多
关键词 Carbon dioxide conversion photo-thermal Plasmonic catalysis Solar thermal
下载PDF
Principles and practices of the photo-thermal adaptability improvement in soybean 被引量:3
4
作者 ZHANG Li-xin LIU Wei +7 位作者 Mesfin Tsegaw XU Xin QI Yan-ping Enoch Sapey LIU Lu-ping WU Ting-ting SUN Shi HAN Tian-fu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第2期295-310,共16页
As a short-day(SD)and thermophilic plant,soybean(Glycine max(L.)Merr.)is sensitive to photo-thermal conditions.This characteristic severely limits the cultivation range of a given soybean cultivar and affects the perf... As a short-day(SD)and thermophilic plant,soybean(Glycine max(L.)Merr.)is sensitive to photo-thermal conditions.This characteristic severely limits the cultivation range of a given soybean cultivar and affects the performances of agronomic traits such as yield,plant architectures,and seed quality.Therefore,understanding the mechanism of photo-thermal sensitivity will provide a theoretical basis for soybean improvement.In this review,we introduce the advances in physiological,genetic,and molecular researches in photoperiodism of soybean,and progress in the improvement of the photo-thermal adaptability.We also summarize the photo-thermal conditions and characteristics of widely-planted soybean cultivars of major production regions in China.Furthermore,we proposed a novel concept of‘ecotyping’and the strategies for widely-adapted soybean cultivar breeding.This review provides an important guide for improving the adaptability of soybean. 展开更多
关键词 SOYBEAN photo-thermal response ADAPTABILITY widely-adapted soybean cultivars
下载PDF
Broadband all-fiber optical phase modulator based on photo-thermal effect in a gas-filled hollow-core fiber 被引量:2
5
作者 Shoulin Jiang Feifan Chen +4 位作者 Yan Zhao Shoufei Gao Yingying Wang Hoi Lut Ho Wei Jin 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第5期10-16,共7页
We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fab... We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fabricated using a 5.6-cm-long anti-resonant hollow-core fiber with pure acetylene filling.It has a half-wave optical power of 289 mW at 100 kHz and an average insertion loss 0.6 dB over a broad wavelength range from 1450 to 1650 nm.The rise and fall time constants are 3.5 and 3.7μs,respectively,2–3 orders of magnitude better than the previously reported microfiber-based photo-thermal phase modulators.The gas-filled hollow-core waveguide configuration is promising for optical phase modulation from ultraviolet to mid-infrared which is challenging to achieve with solid optical fibers. 展开更多
关键词 optical modulators photo-thermal effects hollow-core fibers
下载PDF
Construction of Mo/Mo_(2)C@C modified ZnIn_(2)S_(4)Schottky junctions for efficient photo-thermal assisted hydrogen evolution 被引量:1
6
作者 Xiu-Qing Qiao Wenxuan Chen +4 位作者 Chen Li Zizhao Wang Dongfang Hou Bojing Sun Dong-Sheng Li 《Materials Reports(Energy)》 EI 2023年第4期71-81,共11页
Photocatalytic water splitting on noble metal-free photocatalysts for H_(2) generation is a promising but challenging approach to realize solar-to-chemical energy conversion.In this study,Mo/Mo_(2)C nanoparticles anch... Photocatalytic water splitting on noble metal-free photocatalysts for H_(2) generation is a promising but challenging approach to realize solar-to-chemical energy conversion.In this study,Mo/Mo_(2)C nanoparticles anchored carbon layer(Mo/Mo_(2)C@C)was obtained by a one-step in-situ phase transition approach and developed for the first time as a photothermal cocatalyst to enhance the activity of ZnIn_(2)S_(4)photocatalyst.Mo/Mo_(2)C@C nanosheet exhibits strong absorption in the full spectrum region and excellent photo-thermal conversion ability,which generates heat to improve the reaction temperature and accelerate the reaction kinetics.Moreover,metallic Mo/Mo_(2)C@C couples with ZnIn_(2)S_(4)to form ZnIn_(2)S_(4)-Mo/Mo_(2)C@C Schottky junction(denoted as ZMM),which prevents the electrons back transfer and restrains the charge recombination.In addition,conductive carbon with strong interfacial interaction serves as a fast charge transport bridge.Consequently,the optimized ZMM-0.2 junction exhibits an H2 evolution rate of 1031.07μmol g^(-1)h^-(1),which is 41 and 4.3 times higher than bare ZnIn_(2)S_(4)and ZnIn_(2)S_(4)-Mo2C,respectively.By designing novel photothermal cocatalysts,our work will provide a new guidance for designing efficient photocatalysts. 展开更多
关键词 Molybdenum carbide photo-thermal conversion H_(2)evolution Schottky junction
下载PDF
Preparation of Photo-thermal Cellulose Nanocrystal-based Hydrogel 被引量:3
7
作者 ZiHe Guo Tao Ma ShiYu Fu 《Paper And Biomaterials》 2019年第2期32-39,共8页
Cellulose nanocrystal(CNC)prepared by hydrolysis of cotton linters with sulfuric acid was used to react with chloroauric acid to manufacture a gold nanoparticle/CNC composite.The composite was then graft-copolymerized... Cellulose nanocrystal(CNC)prepared by hydrolysis of cotton linters with sulfuric acid was used to react with chloroauric acid to manufacture a gold nanoparticle/CNC composite.The composite was then graft-copolymerized with N-isopropylacrylamide to obtain a photo-thermal ultrafine gold nanoparticles/CNC-based hydrogel.The hydrogel was studied by performing scanning electron microscopy,and it was found that the prepared hydrogel had a network structure.The temperature of the hydrogel increased from 25℃to 39℃and its volume decreased by 30%when it was exposed to visible light(400~750 nm)for 1 h.The experiment results indicated that the prepared photo-thermal CNC-based hydrogel has thermal responsiveness and photo-thermal properties. 展开更多
关键词 CNC GOLD nanoparticle/CNC composite CNC-based HYDROGEL photo-thermal HYDROGEL
下载PDF
A highly sensitive LITES sensor based on a multi-pass cell with dense spot pattern and a novel quartz tuning fork with low frequency 被引量:3
8
作者 Yahui Liu Shunda Qiao +4 位作者 Chao Fang Ying He Haiyue Sun Jian Liu Yufei Ma 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第3期26-34,共9页
A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manu... A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF. 展开更多
关键词 light-induced thermoelectric spectroscopy quartz tuning fork multi-pass cell gas sensing
下载PDF
Solar energy full-spectrum perfect absorption and efficient photo-thermal generation
9
作者 Zhefu Liao Zhengqi Liu +4 位作者 Qizhao Wu Xiaoshan Liu Xuefeng Zhan Gaorong Zeng Guiqiang Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第8期381-387,共7页
Designing and manufacturing cost-effective absorbers that can cover the full-spectrum of solar irradiation is still critically important for solar harvesting.Utilizing control of the lightwave reflection and transmiss... Designing and manufacturing cost-effective absorbers that can cover the full-spectrum of solar irradiation is still critically important for solar harvesting.Utilizing control of the lightwave reflection and transmission,metamaterials realize high absorption over a relatively wide bandwidth.Here,a truncated circular cone metasurface(TCCM)composed of alternating multiple layers of titanium(Ti)and silicon dioxide(SiO_(2))is presented.Enabled by the synergetic of surface plasmon resonances and Fabry-Pérot resonances,the TCCM simultaneously achieves high absorptivity(exceed 90%),and absorption broadband covers almost the entire solar irradiation spectrum.In addition,the novel absorber exhibits great photo-thermal property.By exploiting the ultrahigh melting point of Ti and SiO_(2),high-efficiency solar irradiation absorption and heat release have been achieved at 700℃when the solar concentration ratio is 500(i.e.,incident light intensity at 5×10^(5) W/m^(2)).It is worth noting that the photo-thermal efficiency is almost unchanged when the incident angle increases from 0°to 45°.The outstanding capacity for solar harvesting and light-to-heat reported in this paper suggests that TCCM has great potential in photothermal therapies,solar desalination,and radiative cooling,etc. 展开更多
关键词 solar energy photo-thermal generation perfect absorption plasmonic
下载PDF
Oxygen-vacancy-anchoring Ni_(x)O_(y) loading towards efficient hydrogen evolution via photo-thermal coupling reaction
10
作者 Qiliang Wu Zheng Li +4 位作者 Xuhan Zhang Chenyu Xu Mingjiang Ni Kefa Cen Yanwei Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第10期77-87,I0003,共12页
Oxygen vacancy(Vo)is a significant component in defect engineering.The present work reports the anchoring effects of initial Vo for further loading modifications and the reducing capacity of photoinduced Vo for pure w... Oxygen vacancy(Vo)is a significant component in defect engineering.The present work reports the anchoring effects of initial Vo for further loading modifications and the reducing capacity of photoinduced Vo for pure water splitting.Herein,we propose Ni-loaded Cu-doped TiO_(2)(NCT)materials by successive doping and loading.The continuously added Ni ions should accumulate around the Vos and gradually grow into complete nickel oxide crystals,achieving a higher average valence state of the Ni species.NiO crystals can be detected on a 0.5%NCT sample,while the structure of Ni_(2)O_(3) has been confirmed with a higher nickel mass ratio.Moreover,the introduction of nickel oxide effectively improves the photochemical and electrochemical performance by the interface charge separation,finally reaching an H2 yield of 30.6 pmol/g-cat on 0.5%NCT for Vo-based photo-thermal coupling reaction,which consists of Vo generation in photo and Vo consumption in thermal environment.In situ infrared spectroscopy further indicated that the presence of high valence state nickel oxide hindered the H2 formation but effectively promoted the conventional oxidizing reaction,with an H2 yield of 20.6 mmol/g-cat in a methanol-water reaction on the 2.0%NCT material.In summary,Vo controls the morphological structure of Ni loading and produces diverse effects for reactions with dissimilar mechanisms,which provides a novel way to design modifications for promoting various chemical reactions. 展开更多
关键词 Oxygen vacancy Nickel oxide Water splitting photo-thermal coupling reaction DFT calculation
下载PDF
Morphological disruption and visual tuning alterations in the primary visual cortex in glaucoma(DBA/2J)mice 被引量:1
11
作者 Yin Yang Zhaoxi Yang +9 位作者 Maoxia Lv Ang Jia Junjun Li Baitao Liao Jing’an Chen Zhengzheng Wu Yi Shi Yang Xia Dezhong Yao Ke Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第1期220-225,共6页
Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the pr... Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma. 展开更多
关键词 DBA/2J DEGENERATION gamma band oscillations GLAUCOMA primary visual cortex(V1) RETINA single-unit recording tuning curve
下载PDF
Manipulation of High-Fidelity Sidebands under Large Detuning by Floquet Technology:Application to Multi-Mode Cooling
12
作者 Xue-Ying Yang Zi-Dong Lin +4 位作者 Shu-Ying Mu Wei Wu Chun-Wang Wu Yi Xie Ping-Xing Chen 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第11期53-61,共9页
The Floquet technology,a powerful way to manipulate quantum states,is employed to drive sidebands transition under large detuning.Our results demonstrate that high fidelities over 99%can be achieved through optimizing... The Floquet technology,a powerful way to manipulate quantum states,is employed to drive sidebands transition under large detuning.Our results demonstrate that high fidelities over 99%can be achieved through optimizing suitable modulation frequencies under large detuning.We observe high-fidelity transitions within a high bandwidth by utilizing a single modulation frequency and reveal that this capability is due to the emergence of a flat-band structure in the bandwidth range.The key finding of high-fidelity sideband manipulation under large detuning is experimentally confirmed in nuclear magnetic resonance platform.Finally,we propose a new parallel sideband cooling scheme that enables simultaneous cooling of multiple motional modes.This approach improves the cooling rate compared to conventional schemes with fixed laser frequency and power,and eliminates the need for mode-specific addressing.Our Floquet parallel scheme is applicable to any harmonic oscillator system and is not limited by bandwidth in theory. 展开更多
关键词 tuning BANDS scheme
下载PDF
Conceptual design of a 714-MHz RFQ for compact proton injectors and development of a new tuning algorithm on its aluminium prototype
13
作者 Yi-Xing Lu Wen-Cheng Fang +1 位作者 Yu-Sen Guo Zhen-Tang Zhao 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期45-58,共14页
Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator facilities.An RFQ with a high frequency of 714 MHz dedicated to compact pro... Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator facilities.An RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this study.The RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary optimization.To develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a prototype.An aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance,fabrication procedure,and feasibility of the tuning algorithm.Eventually,a new tuning algorithm based on the response matrix and least-squares method is developed,which yields favorable results based on the prototype,i.e.,the errors of the dipole and quadrupole components reduced to a low level after several tuning iterations.Benefiting from the conceptual design and techniques obtained from the prototype,the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step. 展开更多
关键词 Compact proton injector RFQ IH-DTL High gradient tuning
下载PDF
基于prompt tuning的中文文本多领域情感分析研究
14
作者 赵文辉 吴晓鸰 +1 位作者 凌捷 HOON Heo 《计算机工程与科学》 CSCD 北大核心 2024年第1期179-190,共12页
不同领域的情感文本表达方式不一样,通常需要为各个领域训练相应的情感分析模型。针对无法用一个模型进行高效多领域情感分析的问题,提出了基于提示微调(prompt tuning)的多领域文本情感分析方法MSAPT。借助hard prompt,指示情感文本的... 不同领域的情感文本表达方式不一样,通常需要为各个领域训练相应的情感分析模型。针对无法用一个模型进行高效多领域情感分析的问题,提出了基于提示微调(prompt tuning)的多领域文本情感分析方法MSAPT。借助hard prompt,指示情感文本的所属领域和待选的情感标签,调动不同领域情感分析相关的知识,再为情感分析预训练一个统一的“通才模型”,在下游的各领域文本学习中,保持模型冻结,通过prompt tuning使模型学习到下游各领域情感文本的特征。MSAPT仅需保存一个模型和一些参数量远远小于模型的prompt,实现了多领域情感分析。在多个属于不同领域的情感文本数据集上进行实验,结果表明仅进行prompt tuning时,MSAPT效果优于模型微调(model tuning)的。最后,分别对适应特定领域的prompt tuning、hard prompt、soft prompt的长度和中间训练数据集的大小进行消融实验,从证明其对情感分析效果的影响。 展开更多
关键词 多领域情感分析 提示微调 预训练语言模型 T5
下载PDF
Improved isochronous mass spectrometry with tune measurement
15
作者 Han-Yu Deng Yuan-Ming Xing +5 位作者 Xu Zhou Yu-Hu Zhang Xin-Liang Yan Jin-Yang Shi Ting Liao Meng Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第11期174-181,共8页
In conventional isochronous mass spectrometry(IMS)performed on a storage ring,the precision of mass measurements for short-lived nuclei depends on the accurate determination of the revolution times(T)of stored ions.Ho... In conventional isochronous mass spectrometry(IMS)performed on a storage ring,the precision of mass measurements for short-lived nuclei depends on the accurate determination of the revolution times(T)of stored ions.However,the resolution of T inevitably deteriorates due to the magnetic rigidity spread of the ions,limiting the mass-resolving power.In this study,we used the betatron tunes Q(the number of betatron oscillations per revolution)of the ions and established a correlation between T and Q.From this correlation,T was transformed to correspond to a fixed Q with higher resolution.Using these transformed T values,the masses of ^(63)Ge,^(65)As,^(67)Se,and ^(71)Kr agreed well with the mass values measured using the newly developed IMS(Bρ-IMS).We also studied the systematics of Coulomb displacement energies(CDEs)and found that anomalous staggering in CDEs was eliminated using new mass values.This method of T transformation is highly effective for conventional IMS equipped with a single time-of-flight detector. 展开更多
关键词 Isochronous Mass Spectrometry Storage ring TUNE Natural chromaticity Nuclear mass measurement
下载PDF
Vibration attenuation performance of wind turbine tower using a prestressed tuned mass damper under seismic excitation
16
作者 Lei Zhenbo Liu Gang +1 位作者 Wang Hui Hui Yi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期511-524,共14页
With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly complex.In particular,seismic excitation can create a resonance response and cau... With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly complex.In particular,seismic excitation can create a resonance response and cause excessive vibration of the WTT.To investigate the vibration attenuation performance of the WTT under seismic excitations,a novel passive vibration control device,called a prestressed tuned mass damper(PS-TMD),is presented in this study.First,a mathematical model is established based on structural dynamics under seismic excitation.Then,the mathematical analytical expression of the dynamic coefficient is deduced,and the parameter design method is obtained by system tuning optimization.Next,based on a theoretical analysis and parameter design,the numerical results showed that the PS-TMD was able to effectively mitigate the resonance under the harmonic basal acceleration.Finally,the time-history analysis method is used to verify the effectiveness of the traditional pendulum tuned mass damper(PTMD)and the novel PS-TMD device,and the results indicate that the vibration attenuation performance of the PS-TMD is better than the PTMD.In addition,the PS-TMD avoids the nonlinear effect due to the large oscillation angle,and has the potential to dissipate hysteretic energy under seismic excitation. 展开更多
关键词 wind turbine tower prestressed tuned mass damper vibration control seismic excitation numerical simulation
下载PDF
Multiscale and Auto-Tuned Semi-Supervised Deep Subspace Clustering and Its Application in Brain Tumor Clustering
17
作者 Zhenyu Qian Yizhang Jiang +4 位作者 Zhou Hong Lijun Huang Fengda Li Khin Wee Lai Kaijian Xia 《Computers, Materials & Continua》 SCIE EI 2024年第6期4741-4762,共22页
In this paper,we introduce a novel Multi-scale and Auto-tuned Semi-supervised Deep Subspace Clustering(MAS-DSC)algorithm,aimed at addressing the challenges of deep subspace clustering in high-dimensional real-world da... In this paper,we introduce a novel Multi-scale and Auto-tuned Semi-supervised Deep Subspace Clustering(MAS-DSC)algorithm,aimed at addressing the challenges of deep subspace clustering in high-dimensional real-world data,particularly in the field of medical imaging.Traditional deep subspace clustering algorithms,which are mostly unsupervised,are limited in their ability to effectively utilize the inherent prior knowledge in medical images.Our MAS-DSC algorithm incorporates a semi-supervised learning framework that uses a small amount of labeled data to guide the clustering process,thereby enhancing the discriminative power of the feature representations.Additionally,the multi-scale feature extraction mechanism is designed to adapt to the complexity of medical imaging data,resulting in more accurate clustering performance.To address the difficulty of hyperparameter selection in deep subspace clustering,this paper employs a Bayesian optimization algorithm for adaptive tuning of hyperparameters related to subspace clustering,prior knowledge constraints,and model loss weights.Extensive experiments on standard clustering datasets,including ORL,Coil20,and Coil100,validate the effectiveness of the MAS-DSC algorithm.The results show that with its multi-scale network structure and Bayesian hyperparameter optimization,MAS-DSC achieves excellent clustering results on these datasets.Furthermore,tests on a brain tumor dataset demonstrate the robustness of the algorithm and its ability to leverage prior knowledge for efficient feature extraction and enhanced clustering performance within a semi-supervised learning framework. 展开更多
关键词 Deep subspace clustering multiscale network structure automatic hyperparameter tuning SEMI-SUPERVISED medical image clustering
下载PDF
Parameters Optimization and Performance Evaluation of the Tuned Inerter Damper for the Seismic Protection of Adjacent Building Structures
18
作者 Xiaofang Kang Jian Wu +1 位作者 Xinqi Wang Shancheng Lei 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期551-593,共43页
In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in ... In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in serial or in parallel.The dynamic equations of TID adjacent building damping systems were derived,and the H2 norm criterion was used to optimize and adjust them,so that the system had the optimum damping performance under white noise random excitation.Taking TID frequency ratio and damping ratio as optimization parameters,the optimum analytical solutions of the displacement frequency response of the undamped structure under white noise excitation were obtained.The results showed that compared with the classic TMD,TID could obtain a better damping effect in the adjacent buildings.Comparing the TIDs composed of serial or parallel,it was found that the parallel TIDs had more significant advantages in controlling the peak displacement frequency response,while the H2 norm of the displacement frequency response of the damping system under the coupling of serial TID was smaller.Taking the adjacent building composed of two ten-story frame structures as an example,the displacement and energy collection time history analysis of the adjacent building coupled with the optimum design parameter TIDs were carried out.It was found that TID had a better damping effect in the full-time range compared with the classic TMD.This paper also studied the potential power of TID in adjacent buildings,which can be converted into available power resources during earthquakes. 展开更多
关键词 Adjacent buildings tuned inerter damper(TID) H2 norm optimization vibration control energy harvesting
下载PDF
Classification of Conversational Sentences Using an Ensemble Pre-Trained Language Model with the Fine-Tuned Parameter
19
作者 R.Sujatha K.Nimala 《Computers, Materials & Continua》 SCIE EI 2024年第2期1669-1686,共18页
Sentence classification is the process of categorizing a sentence based on the context of the sentence.Sentence categorization requires more semantic highlights than other tasks,such as dependence parsing,which requir... Sentence classification is the process of categorizing a sentence based on the context of the sentence.Sentence categorization requires more semantic highlights than other tasks,such as dependence parsing,which requires more syntactic elements.Most existing strategies focus on the general semantics of a conversation without involving the context of the sentence,recognizing the progress and comparing impacts.An ensemble pre-trained language model was taken up here to classify the conversation sentences from the conversation corpus.The conversational sentences are classified into four categories:information,question,directive,and commission.These classification label sequences are for analyzing the conversation progress and predicting the pecking order of the conversation.Ensemble of Bidirectional Encoder for Representation of Transformer(BERT),Robustly Optimized BERT pretraining Approach(RoBERTa),Generative Pre-Trained Transformer(GPT),DistilBERT and Generalized Autoregressive Pretraining for Language Understanding(XLNet)models are trained on conversation corpus with hyperparameters.Hyperparameter tuning approach is carried out for better performance on sentence classification.This Ensemble of Pre-trained Language Models with a Hyperparameter Tuning(EPLM-HT)system is trained on an annotated conversation dataset.The proposed approach outperformed compared to the base BERT,GPT,DistilBERT and XLNet transformer models.The proposed ensemble model with the fine-tuned parameters achieved an F1_score of 0.88. 展开更多
关键词 Bidirectional encoder for representation of transformer conversation ensemble model fine-tuning generalized autoregressive pretraining for language understanding generative pre-trained transformer hyperparameter tuning natural language processing robustly optimized BERT pretraining approach sentence classification transformer models
下载PDF
Optimizing Enterprise Conversational AI: Accelerating Response Accuracy with Custom Dataset Fine-Tuning
20
作者 Yash Kishore 《Intelligent Information Management》 2024年第2期65-76,共12页
As the realm of enterprise-level conversational AI continues to evolve, it becomes evident that while generalized Large Language Models (LLMs) like GPT-3.5 bring remarkable capabilities, they also bring forth formidab... As the realm of enterprise-level conversational AI continues to evolve, it becomes evident that while generalized Large Language Models (LLMs) like GPT-3.5 bring remarkable capabilities, they also bring forth formidable challenges. These models, honed on vast and diverse datasets, have undoubtedly pushed the boundaries of natural language understanding and generation. However, they often stumble when faced with the intricate demands of nuanced enterprise applications. This research advocates for a strategic paradigm shift, urging enterprises to embrace a fine-tuning approach as a means to optimize conversational AI. While generalized LLMs are linguistic marvels, their inability to cater to the specific needs of businesses across various industries poses a critical challenge. This strategic shift involves empowering enterprises to seamlessly integrate their own datasets into LLMs, a process that extends beyond linguistic enhancement. The core concept of this approach centers on customization, enabling businesses to fine-tune the AI’s functionality to fit precisely within their unique business landscapes. By immersing the LLM in industry-specific documents, customer interaction records, internal reports, and regulatory guidelines, the AI transcends its generic capabilities to become a sophisticated conversational partner aligned with the intricacies of the enterprise’s domain. The transformative potential of this fine-tuning approach cannot be overstated. It enables a transition from a universal AI solution to a highly customizable tool. The AI evolves from being a linguistic powerhouse to a contextually aware, industry-savvy assistant. As a result, it not only responds with linguistic accuracy but also with depth, relevance, and resonance, significantly elevating user experiences and operational efficiency. In the subsequent sections, this paper delves into the intricacies of fine-tuning, exploring the multifaceted challenges and abundant opportunities it presents. It addresses the technical intricacies of data integration, ethical considerations surrounding data usage, and the broader implications for the future of enterprise AI. The journey embarked upon in this research holds the potential to redefine the role of conversational AI in enterprises, ushering in an era where AI becomes a dynamic, deeply relevant, and highly effective tool, empowering businesses to excel in an ever-evolving digital landscape. 展开更多
关键词 Fine-tuning DATASET AI CONVERSATIONAL ENTERPRISE LLM
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部