检索结果-南通市图书馆

Conceptual design of a 714-MHz RFQ for compact proton injectors and development of a new tuning algorithm on its aluminium prototype

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 45-58页

作者： Yi-Xing Lu wen-Cheng Fang Yu-Sen Guo Zhen-Tang zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800China University of Chinese Academy of Sciences Beijing 101408China Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204China Shanghai Key Laboratory of Cryogenics&Superconducting RF Technology Shanghai 201800China ShanghaiTech University Shanghai 201210China

Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator *** RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this *** 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 *** develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a *** 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 ***,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 *** 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.

关键词： Compact proton injector RFQ IH-DTL High gradient Tuning

Numerical investigation of the coupled aero-hydrodynamic performances of a semi-submersible floating offshore wind turbine with inclined columns

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 316-330页

作者： Ying-jie Xue Xiao-long Yang Wei-wen zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Offshore Oil Engineering Co.Ltd. Tianjin300461China

Numerical investigations of floating platforms with different outer column inclined angles under two operating conditions of regular wave and irregular wave are presented in this paper.A coupled aero-hydrodynamic computational fluid dynamics in-house solver FOWT-UALM-SJTU is applied for the ***,the validation for wave and wind generation are conducted to determine mesh distribution *** on these,the hydrodynamic motion response,aerodynamic performance and wake flow are analyzed to explore the impact of inclined *** spectral analysis on the motion response under wave action,discuss the aerodynamic attack angle and inflow wind velocity along the blade spanwise direction in detail,reveal different trends in wake development and *** results show that for the regular wave condition with the increase of inclined angles,the equilibrium position of surge motion is constantly rising,while pitch is *** maximum root mean square(rms)value occurs at angle=30°,compared with the original OC4 FOWT,the rms in power and thrust increase 0.35%,0.71%.And there are two low regions of attack angle and high regions of axial inflow velocity,corresponding to aerodynamic *** spectral analysis indicates that the natural frequency of pitch motion will increase with inclined ***,from the middle to far region of wake flow,the velocity recovery of FOWT with inclined angle will become faster,which is beneficial for downstream turbines to enhance more wind energy.

关键词： Floating offshore wind turbine numerical simulation aero-hydrodynamic coupled analysis floating platform with inclinedcolumns wake flow recovery

Distributed Stochastic Scheduling of Massive Backup Batteries in Cellular Networks for Operational Reserve and Frequency Support Ancillary Services

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 393-404页

作者： Kun Li Jiakun Fang Xiaomeng Ai Shichang Cui Rongkang zhao Jinyu wen State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China IEEE

Base station(BS)backup batteries(BSBBs),with their dispatchable capacity,are potential demand-side resources for future power *** enhance the power supply reliability and post-contingency frequency security of power systems,we propose a two-stage stochastic unit commitment(UC)model incorporating operational reserve and post-contingency frequency support provisions from massive BSBBs in cellular networks,in which the minimum backup energy demand is considered to ensure BS power supply *** energy,operational reserve,and frequency support ancillary services are co-optimized to handle the power balance and post-contingency frequency security in both forecasted and stochastic variable renewable energy(VRE)***,we propose a dedicated and scalable distributed optimization framework to enable autonomous optimizations for both dispatching center(DC)and *** BS model parameters are stored and processed locally,while only the values of BS decision variables are required to upload to DC under the proposed distributed optimization framework,which safeguards BS privacy *** studies on a modified IEEE 14-bus system demonstrate the effectiveness of the proposed method in promoting VRE accommodation,ensuring post-contingency frequency security,enhancing operational economics,and fully utilizing BSBBs'energy and power ***,the proposed distributed optimization framework has been validated to converge to a feasible solution with near-optimal performance within limited ***,numerical results on the Guangdong 500 kV provincial power system in China verify the scalability and practicality of the proposed distributed optimization framework.

关键词： Base station backup battery operational reserve frequency security distributed optimization privacy

Topology optimization of chiral metamaterials with application to underwater sound insulation

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1119-1138页

作者： Chao WANG Honggang zhao Yang WANG Jie ZHONG Dianlong YU Jihong wen Laboratory of Science and Technology on Integrated Logistics Support National University of Defense TechnologyChangsha410073China

Chiral metamaterials have been proven to possess many appealing mechanical phenomena,such as negative Poisson's ratio,high-impact resistance,and energy *** work extends the applications of chiral metamaterials to underwater sound *** chiral metamaterials with low acoustic impedance and proper stiffness are inversely designed using the topology optimization *** acoustic impedance enables the metamaterials to have a high and broadband sound transmission loss(STL),while proper stiffness guarantees its robust acoustic performance under a hydrostatic *** proof-of-concept demonstrations,two specimens are fabricated and tested in a water-filled impedance *** results show that,on average,over 95%incident sound energy can be isolated by the specimens in a broad frequency range from 1 k Hz to 5 k Hz,while the sound insulation performance keeps stable under a certain hydrostatic *** work may provide new insights for chiral metamaterials into the underwater applications with sound insulation.

关键词： chiral metamaterial topology optimization underwater sound insulation low acoustic impedance sound transmission loss(STL)

Overview of ferroptosis and pyroptosis in acute liver failure

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第34期30卷 3856-3861页

作者： Ya-wen Sun Bo-wen zhao Hai-Fang Li Guang-Xiao Zhang College of Life Sciences Shandong Agricultural UniversityTai’an 271018Shandong ProvinceChina

In this editorial,we comment on the article by Zhou et al published in a recent *** specifically focus on the crucial roles of ferroptosis and pyroptosis in acute liver failure(ALF),a disease with high mortality *** is the result of increased intracellular reactive oxygen species due to iron accumulation,glutathione(GSH)depletion,and decreased GSH peroxidase 4 activity,while pyroptosis is a procedural cell death mediated by gasdermin D which initiates a sustained inflammatory *** this review,we describe the characteristics of ferroptosis and pyroptosis,and discuss the involvement of the two cell death modes in the onset and development of ***,we summarize several interfering methods from the perspective of ferroptosis and pyroptosis for the alleviation of *** observations might provide new targets and a theoretical basis for the treatment of ALF,which are also crucial for improving the prognosis of patients with ALF.

关键词： Acute liver failure Ferroptosis Pyroptosis Glutathione peroxidase 4 Gasdermin D

Few-shot skin cancer detection based on many-objective optimization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Kongzhi yu Juece/Control and Decision 2024年第11期39卷 3597-3606页

作者： zhao, Jia-Hui wen, Jie Cai, Xing-Juan Cui, zhi-Hua Shanxi Key Laboratory of Big Data Analysis and Parallel Taiyuan University of Science and Technology Taiyuan 030024 China Shanxi Key Laboratory of Advanced Control and Equipment Ⅰntelligence Taiyuan University of Science and Technology Taiyuan 030024 China

Due to the long-tailed distribution characteristics of skin cancer data, quickly identifying rare skin disease samples with small amounts of data becomes a challenging few-shot problem. The detection method based on meta-learning can quickly learn meta-knowledge from the majority of common classes skin disease classes and use prior knowledge to improve the model’s ability to detect rare skin diseases. However, the bias in the quality and distribution of public skin cancer categories leads to the risk of overfitting in the pre-training phase of meta-learning, and meta-learning models based on traditional networks struggle to handle fine-grained skin disease problems. Affronting this issue, a many-objective meta-learning skin cancer detection model is proposed. The proposed model optimizes the distribution of common classes (base classes) by considering various classification performances of the skin cancer detection model, thus obtaining quality-enhanced training samples. And it adopts the ResNet12 network structure integrated with the CCNet attention model, which can significantly enhance the ability to identify fine-grained skin lesion images. Additionally,an improved many-objective optimization algorithm with discrete grouping strategy is designed to efficiently solve the proposed model. Some experiments are conducted on two public medical datasets, ⅠSCⅠ2018 and Derm7pt. The proposed many-objective skin detection model achieves detection accuracies of 67 %, 79 %, and 82 % respectively on binary classification tasks with 1-shot, 3-shot, and 5-shot learning,which validates the effectiveness of the model. © 2024 Northeast University. All rights reserved.

关键词： Contrastive Learning

Radical Mechanism of IrⅢ/NiⅡ-Metallaphotoredox Catalyzed C(sp3)-H Functionalization Triggered by Single-Electron Transfer:Theoretical Insight

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Radical Mechanism of IrⅢ/NiⅡ-Metallaphotoredox Catalyzed C...

Microphase Separation of Semiflexible Ring Diblock Copolymers

中国化学会·第十三届全国物理有机化学学术会议

作者： Yu-Jiao Dong Bo Zhu zhi-wen zhao Wei Guan Faculty of Chemistry Northeast Normal University

Photoredox-mediated iridium/nickel dual catalysis as a powerful strategy has been widely used to develop challenging C-H functionalization reactions. Photoredox catalysis can be induced to activate organic substrates ...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 267-276,I0011页

作者： Dan-Yan Qin Sheng-Da zhao zhi-Xin Liu Jing Zhang Xing-Hua Zhang School of Physical Science and Engineering Beijing Jiaotong UniversityBeijing100044China

Aiming at the difficult problem of solving the conformation statistics of complex polymers, this study presents a novel and concise conformation statistics theoretical approach based on Monte Carlo and Neural Network method. This method offers a new research idea for investigating the conformation statistics of complex polymers, characterized by its simplicity and practicality. It can be applied to more complex topological structure, more higher degree of freedom polymer systems with higher dimensions, theory research on dynamic self-consistent field theory and polymer field theory, as well as the analysis of scattering experimental data. The conformation statistics of complex polymers determine the structure and response properties of the system. Using the new method proposed in this study, taking the semiflexible ring diblock copolymer as an example, Monte Carlo simulation is used to sample this ring conformation to construct the dataset of polymer. The structure factor describing conformation statistics are expressed as continuous functions of structure parameters by neural network supervised learning. This is the innovation of this work. As an application, the structure factors represented by neural networks were introduced into the random phase approximation theory to study the microphase separation of semiflexible ring diblock copolymers. The influence of the ring's topological properties on the phase transition behavior was pointed out.

关键词： Ring copolymer Diblock copolymers Semiflexible The order-disorder transition

Strip flatness prediction of cold rolling based on ensemble methods

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 237-251页

作者： Wu-quan Yang zhi-ting zhao Liang-yu Zhu Xun-yang Gao Li Wang School of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang110142LiaoningChina

Aiming at the problem of insufficient prediction accuracy of strip flatness at the outlet of cold tandem rolling,the prediction performance of strip flatness based on different ensemble methods was studied and a high-precision prediction ensemble model of strip flatness at the outlet was ***,based on linear regression(LR),K nearest neighbors(KNN),support vector regression,regression trees(RT),and backpropagation neural network(BPN),bagging,boosting,and stacking ensemble methods were used for ensemble ***,three existing ensemble models,i.e.,random forest,extreme random tree(ET)and extreme gradient boosting,were used to conduct experiments and compare the *** research shows that bagging,boosting,and stacking three ensemble methods have the most significant improvement in the prediction accuracy of the regression trees model,which is increased by 5.28%,6.51%,and 5.32%,*** the same time,the stacking ensemble method improves both the simple model and the complex model,and the improvement effect on the simple base model is the greatest,which is 4.69%higher than that of the base model *** all of the ensemble models,the stacking ensemble model of level-1(ET,AdaBoost-RT,LR,BPN)paired with level-2(LR)was discovered to be the best model(EALB-LR)and can be further studied for industrial applications.

关键词： Tandem cold rolling Flatness prediction Machine learning Ensemble method