检索结果-南通市图书馆

Chinese Physics B 2021年第7期30卷 289-293页

作者： Jiu-Lin Yang Guo-Ying Feng du-xin qing Ya-Jie Wu Yun Luo Jian-Jun Wang Institute of Laser&Micro/Nano Engineering College of Electronics and Information EngineeringSichuan UniversityChengdu 610064China Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China

High-quality Fe-doped Zn S films have been fabricated by electron beam *** the doping,the fabricated films still maintain the preferential crystalline orientation and phase purity of the host Zn *** to the observation of surface morphology,the root mean-square roughness of the samples increases slightly with the increase of doping *** of the prepared samples are in cubic zinc blende structure of Zn *** spectrum confirms a more obvious dip near 3μm with higher dopant concentration and it can be attributed to the typical^(5)E→^(5)T_(2)transition of Fe^(2+).Fe-doped Zn S film is also successfully used for Q-switched Er:ZBLAN fiber laser.

关键词： Fe-doped ZnS film electron beam evaporation Q-switching Er:ZBLAN

Influences of annealing temperature on properties of Fe^2+:ZnSe thin films deposited by electron beam evaporation and their applications to Q-switched fiber laser

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第5期29卷 282-287页

作者： du-xin qing Shu-Tong Wang Shou-Gui Ning Wei Zhang Xiao-Xu Chen Hong Zhang Guo-Ying Feng Shou-Huan Zhou Institute of Laser&Micro/Nano Engineering College of Electronics&Information EngineeringSichuan UniversityChengdu 610064China North China Research Institute of Electro-Optics Beijing 100015China

Fe^2+:ZnSe thin films are prepared on sapphire substrate at room temperature by electron beam evaporation and then annealed in vacuum(about 1×10^-4 Pa)at different *** influences of thermal annealing on the structural and optical properties of these films such as grain size and optical transmittance are *** x-ray diffraction patterns show that the Fe2+:ZnSe thin film is preferred to be oriented along the(111)plane at different annealing *** the film is annealed,the full-width-at-half-maximum(FWHM)of the x-ray diffraction peak profile(111)of the film decreases and its crystal quality is *** electron microscope images show that the films are more dense after being ***,the sample is used as a saturable absorber in ZBLAN fiber *** annealed Fe^2+:ZnSe thin films can be used to realize stable Q-switching modulation on ZBLAN fiber *** results demonstrate that the Fe2+:ZnSe thin film is a promising material for generating the high-power pulses of mid-infrared Q-switched fiber lasers.

关键词： electron beam evaporation thin film optical materials Q-switching

Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 106-117页

作者： xin Shao qing Liu Zicheng xin Jiangshan Zhang Tao Zhou Shaoshuai Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Engineering Research Center of MES Technology for Iron&Steel Production Ministry of EducationBeijing 100083China Laiwu Iron and Steel Group Yinshan Section Steel Co. Ltd.Jinan 271104China

The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter.

关键词： basic oxygen furnace oxygen consumption oxygen blowing time oxygen balance mechanism deep neural network hybrid model

A Coupled Thermomechanical Crack Propagation Behavior of Brittle Materials by Peridynamic Differential Operator

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 339-361页

作者： Tianyi Li xin Gu qing Zhang College of Architectural Engineering Jiangsu Open UniversityNanjing210036China Department of Engineering Mechanics Hohai UniversityNanjing211100China

This study proposes a comprehensive,coupled thermomechanical model that replaces local spatial derivatives in classical differential thermomechanical equations with nonlocal integral forms derived from the peridynamic differential operator(PDDO),eliminating the need for calibration *** model employs a multi-rate explicit time integration scheme to handle varying time scales in multi-physics *** simulations conducted on granite and ceramic materials,this model demonstrates its *** successfully simulates thermal damage behavior in granite arising from incompatible mineral expansion and accurately calculates thermal crack propagation in ceramic slabs during *** account for material heterogeneity,the model utilizes the Shuffle algorithm andWeibull distribution,yielding results that align with numerical simulations and experimental *** coupled thermomechanical model shows great promise for analyzing intricate thermomechanical phenomena in brittle materials.

关键词： Peridynamic differential operator thermomechanical coupling heterogeneity numerical simulation

Helmholtz decomposition with a scalar Poisson equation in elastic anisotropic media

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1597-1610页

作者： xin-Yu Fang Gang Yao qing-qing Zheng Ping-Min Zhang Di Wu Feng-Lin Niu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Unconventional Petroleum Research Institute China University of Petroleum(Beijing)Beijing102249China Department of Mathematics College of ScienceChina University of Petroleum(Beijing)Beijing102249China College of Geophysics China University of Petroleum(Beijing)Beijing102249China Department of Earth Environmental and Planetary SciencesRice UniversityHoustonTX77005UA

P-and S-wave separation plays an important role in elastic reverse-time *** can reduce the artifacts caused by crosstalk between different modes and improve image *** addition,P-and Swave separation can also be used to better understand and distinguish wave types in complex *** present,the methods for separating wave modes in anisotropic media mainly include spatial nonstationary filtering,low-rank approximation,and vector Poisson *** of these methods require multiple Fourier transforms or the calculation of large matrices,which require high computational costs for problems with large *** this paper,an efficient method is proposed to separate the wave mode for anisotropic media by using a scalar anisotropic Poisson operator in the spatial *** 2D problems,the computational complexity required by this method is 1/2 of the methods based on solving a vector Poisson ***,compared with existing methods based on pseudoHelmholtz decomposition operators,this method can significantly reduce the computational *** examples also show that the P and S waves decomposed by this method not only have the correct amplitude and phase relative to the input wavefield but also can reduce the computational complexity significantly.

关键词： Anisotropic media Scalar anisotropic Poisson equation Improved elastic wavefield decomposition

Optimal Strategy for Aircraft Pursuit-evasion Games via Self-play Iteration

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第3期21卷 585-596页

作者： xin Wang qing-Lai Wei Tao Li Jie Zhang State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China Institute of Systems Engineering Macao University of Science and TechnologyMacao999078China

In this paper,the pursuit-evasion game with state and control constraints is solved to achieve the Nash equilibrium of both the pursuer and the evader with an iterative self-play *** the condition where the Hamiltonian formed by means of Pontryagin’s maximum principle has the unique solution,it can be proven that the iterative control law converges to the Nash equilibrium ***,the strong nonlinearity of the ordinary differential equations formulated by Pontryagin’s maximum principle makes the control policy difficult to figured *** the system dynamics employed in this manuscript contains a high dimensional state vector with *** practical applications,such as the control of aircraft,the provided overload is ***,in this paper,we consider the optimal strategy of pursuit-evasion games with constant constraint on the control,while some state vectors are restricted by the function of the *** address the challenges,the optimal control problems are transformed into nonlinear programming problems through the direct collocation ***,two numerical cases of the aircraft pursuit-evasion scenario are given to demonstrate the effectiveness of the presented method to obtain the optimal control of both the pursuer and the evader.

关键词： Differential games pursuit-evasion games nonlinear control optimal control Nash equilibrium solution

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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 Iron and Steel Research International 2024年第4期31卷 894-908页

作者： Yan-li xin Zhi-ying Gao Bo Tian qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter

Cetuximab combined with chemotherapy for simultaneous esophageal squamous cell carcinoma and colon adenocarcinoma:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第15期12卷 2649-2654页

作者： xin-xin Luo Yu-Xuan du Qi-qing Zhang Lin Zhang Shu-Ying Zeng Zhi-Hong Yu Peng Shen Zheng-Quan Feng The Second School of Clinical Medicine Zhejiang Chinese Medical UniversityHangzhou310053Zhejiang ProvinceChina Department of Oncology Tongde Hospital of Zhejiang ProvinceHangzhou 310012Zhejiang ProvinceChina Department of Medical Oncology The First Affiliated HospitalMedical College of Zhejiang UniversityHangzhou 310003Zhejiang ProvinceChina

BACKGROUND Multiple primary carcinomas(MPCs)are defined as two or more independent primary cancers that occur simultaneously or sequentially in the same *** MPCs are rarer than solitary cancers or metachronous *** diagnoses of synchronous MPCs and the choice of treatment are critical for successful outcomes in these *** SUMMARY A 64-year-old patient presented with dysphagia,without obvious cause.A diagnosis of synchronous esophageal squamous cell carcinoma and colon adenocarcinoma with liver metastasis was confirmed based on examination and laboratory *** multi-disciplinary consultations,combination chemotherapy(a 3-wk cycle with oxaliplatin 212 mg administered on day 1 and capecitabine 1.5 g twice daily on days 1-14)and esophageal cancer radiotherapy were *** on the results of genetic testing,we switched to a regimen of leucovorin+fluorouracil+oxaliplatin and cetuximab regimen for 8 ***,capecitabine and bevacizumab were administered until the most recent follow-up,at which the tumor remained *** Successful cetuximab chemotherapy treatment provides a reference for the nonoperative and homogeneous treatment of different pathological types of synchronous MCPs.

关键词： Synchronous multiple primary carcinoma Esophageal squamous cell carcinoma Colon adenocarcinoma Cetuximab Chemotherapy Case report

A Comparative Study on the Post-Buckling Behavior of Reinforced Thermoplastic Pipes(RTPs)Under External Pressure Considering Progressive Failure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第2期38卷 233-246页

作者： DING xin-dong WANG Shu-qing LIU Wen-cheng YE Xiao-han College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China Department of Marine Technology Norwegian University of Science and Technology(NTNU)Trondheim NO-7491Norway

The collapse pressure is a key parameter when RTPs are applied in harsh deep-water *** investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are *** the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary *** for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with *** has been observed that the cross-section of the middle part collapses when it reaches the maximum *** collapse pressure obtained from the numerical simulations agrees well with that in the ***,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also *** has a relatively greater difference because of the ignorance of the progressive failure of *** the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.

关键词： reinforced thermoplastic pipes post-buckling behavior progressive failure of composites debonding initial ovality

The effects of various factors on spontaneous imbibition in tight oil reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 315-326页

作者： Cheng Liu Tian-Ru Wang qing You Yue-Chun du Guang Zhao Cai-Li Dai School of Energy Resources China University of GeosciencesBeijing100083PR China School of Petroleum Engineering China University of PetroleumQingdao266580ShandongPR China

Slickwater fracturing fluids have gained widespread application in the development of tight oil reservoirs. After the fracturing process, the active components present in slickwater can directly induce spontaneous imbibition within the reservoir. Several variables influence the eventual recovery rate within this procedure, including slickwater composition, formation temperature, degree of reservoir fracture development, and the reservoir characteristics. Nonetheless, the underlying mechanisms governing these influences remain relatively understudied. In this investigation, using the Chang-7 block of the Changqing Oilfield as the study site, we employ EM-30 slickwater fracturing fluid to explore the effects of the drag-reducing agent concentration, imbibition temperature, core permeability, and core fracture development on spontaneous imbibition. An elevated drag-reducing agent concentration is observed to diminish the degree of medium and small pore utilization. Furthermore, higher temperatures and an augmented permeability enhance the fluid flow properties, thereby contributing to an increased utilization rate across all pore sizes. Reduced fracture development results in a lower fluid utilization across diverse pore types. This study deepens our understanding of the pivotal factors affecting spontaneous imbibition in tight reservoirs following fracturing. The findings act as theoretical, technical, and scientific foundations for optimizing fracturing strategies in tight oil reservoir transformations.

关键词： Tight oil reservoir Spontaneous imbibition Nuclear magnetic resonance Slickwater fracturing fluid Fluid utilization degree