检索结果-南通市图书馆

Phonon-phonon interaction and parametric down-conversion generation in multimode optomechanical systems

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第3期75卷 20-28页

作者： zhen-Yang peng Ying-Dan Wang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We studied the process of polariton conversion in a 3-mode nonlinear optomechanical *** with the standard 2-mode optomechanical system,we find a much larger conversion rate of polariton modes can be achieved under typical dissipation *** obtain a transparent understanding of the relevant physical process,we show that in the large detuned case,the cavity can be eliminated adiabatically,resulting in a parametric down-conversion(PDC)interaction between two phononic polariton *** tuning cavity detuning,the nonlinear interaction can be enhanced with the frequency-matching *** from analytical treatment based on the effective PDC model agree with the numerical *** a system provides potential applications in nonlinear phononics.

关键词： nonlinear optomechanical system parametric down-conversion adiabatic elimination

Reaction mechanisms between molten CaF2-based slags and molten 9CrMoCoB steel

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第5期27卷 611-619页

作者： Lei-zhen peng Zhou-hua Jiang Xin Geng School of Metallurgy Northeastern UniversityShenyang 110819China

Investigating the reaction mechanism between slag and 9CrMoCoB steel is important to develop the proper slag and produce qualified ingots in the electroslag remelting(ESR) process. Equilibrium reaction experiments between molten 9CrMoCoB steel and the slags of 55 wt%CaF2–20 wt%CaO–3 wt%MgO–22 wt%Al2O3–xwt%B2O3(x = 0.0, 0.5, 1.0, 1.5, 2.0, 3.0) were conducted. The reaction mechanisms between molten 9 CrMoCoB steel and the slags with different B2O3 contents were deduced based on the composition of the steel and slag samples at different reaction times. Results show that B content in the steel can be controlled within the target range when the B2O3 content is 0.5 wt% and the FeO content ranges from 0.18 wt% to 0.22 wt% in the slag. When the B2O3 content is ≥1 wt%, the reaction between Si and B2O3 leads to the increase of the B content of steel. The additions of SiO2 and B2O3 to the slag should accord to the mass ratio of [B]/[Si] in the electrode, and SiO2 addition inhibits the reaction between Si and Al2O3.

关键词： 9CrMoCoB electroslag remelting B2O3 thermodynamic calculation reaction mechanism

Second-order Optimality Conditions for Cone-subarcwise Connected Set-valued Optimization Problems

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2018年第1期34卷 183-196页

作者： zhen-hua peng Yi-hong XU Department of Mathematics Nanchang University

The concept of a cone subarcwise connected set-valued map is introduced. Several examples are given to illustrate that the cone subarcwise connected set-valued map is a proper generalization of the cone arcwise connected set-valued map, as well as the arcwise connected set is a proper generalization of the convex set,respectively. Then, by virtue of the generalized second-order contingent epiderivative, second-order necessary optimality conditions are established for a point pair to be a local global proper efficient element of set-valued optimization problems. When objective function is cone subarcwise connected, a second-order sufficient optimality condition is also obtained for a point pair to be a global proper efficient element of set-valued optimization problems.

关键词： cone subarcwise connected set-valued map generalized contingent epiderivative global proper efficiency optimality condition

Short-Term Wind Power Prediction Based on WVMD and Spatio-Temporal Dual-Stream Network

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第10期81卷 549-566页

作者： Yingnan Zhao Yuyuan Ruan zhen peng School of Computer and Science Nanjing University of Information Science and TechnologyNanjing210044China

As the penetration ratio of wind power in active distribution networks continues to increase,the system exhibits some characteristics such as randomness and *** and accurate short-term wind power prediction is essential for algorithms like scheduling and optimization *** on the spatio-temporal features of Numerical Weather Prediction(NWP)data,it proposes the WVMD_DSN(Whale Optimization Algorithm,Variational Mode Decomposition,Dual Stream Network)*** model first applies Pearson correlation coefficient(PCC)to choose some NWP features with strong correlation to wind power to form the feature ***,it decomposes the feature set using Variational Mode Decomposition(VMD)to eliminate the nonstationarity and obtains Intrinsic Mode Functions(IMFs).Here Whale Optimization Algorithm(WOA)is applied to optimise the key parameters of VMD,namely the number of mode components K and penalty factor ***,incorporating attention mechanism(AM),Squeeze-Excitation Network(SENet),and Bidirectional Gated Recurrent Unit(BiGRU),it constructs the dual-stream network(DSN)for short-term wind power *** experiments demonstrate that the WVMD_DSN model outperforms existing baseline algorithms and exhibits good generalization *** relevant code is available at https://***/ruanyuyuan/***(accessed on 20 August 2024).

关键词： Wind power prediction dual-stream network variational mode decomposition(VMD) whale optimization algorithm(WOA)

Electric transport mechanism and magnetoresistance of La_(0.80)Sr_(0.15)Ag_(0.05)MnO_3/x(CuO)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2015年第5期34卷 329-333页

作者： peng Liu Gui-Ying Wang Qiang Mao Ning Liu zhen-Sheng peng Anhui Key Laboratory of Spintronic and Nano-metric Materials School of Mechanics of Electronic Engineering Suzhou University School of Electrical Engineering Anhui Engineering University

The samples of La0.80Sr0.15Ag0.05MnO3/x（CuO）（x = 0, 0.05, 0.10, 0.15, 0.20） were prepared by the solid-state reaction method, and the structure of the sampies was detected by X-ray diffraction （XRD）, scanning electron microscope （SEM） equipped with energy dispersive spectroscopy （EDS）, electric transport mechanism, and magnetoresistance enhancement, and the temperature stability of magnetoresistance of the samples was studied through resistivity-temperature （ρ-T） curves, ρ-T fitted curves, and magnetoresistance-temperature （MR-T） curves. The results indicate that ρ-T data can be fitted by the formula ρ = ρ0 ＋ AT^2 very well, and the electric transport mechanism of all the samples in metal-like area is the scattering of single magneton upon spin electron; the magnetoresistance of composite samples is far larger than that of the original material, and the MR peak value of the sample with x = 0.20 is nearly 4 times as large as that of the sample with x = 0; composite samples have comparatively good temperature stability of magnetoresistance in the temperature range of 200-260 K, and the magnetoresistance of the sample with x = 0.15 almost does not change with temperature and keeps at （5.03 ± 0.20） % in the temperature range of 210-260 K.

关键词： Temperature stability of magnetoresistance Magnetoresistance enhancement Electric transport mechanism Two-phase composite

HSH-carbon: A novel sp^(2)–sp^(3) carbon allotrope with an ultrawide energy gap

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2022年第6期17卷 79-84页

作者： Jia-Qi Liu Qian Gao zhen-peng Hu School of Physics Nankai UniversityTianjin 300071China

An sp^(2)-sp^(3) hybrid carbon allotrope named HSH-carbon is proposed by the first-principles *** structure of HSH-carbon can be regarded as a template polymerization of[1.1.1]propellane molecules in a hexagonal lattice,as well as,an AA stacking of recently reported HSH-C10 consisting of carbon trigonal *** on calculations,the stability of this structure is demonstrated in terms of the cohesive energy,phonon dispersion,Born–Huang stability criteria,and ab initio molecular *** is predicted to be a semiconductor with an indirect energy gap of 3.56 eV at the PBE level or 4.80 eV at the HSE06 *** is larger than the gap of Si and close to the gap of c-diamond,which indicates HSH-carbon is potentially an ultrawide bandgap *** effective masses of carriers in the VB and CB edge are comparable with wide bandgap semiconductors such as GaN and *** elastic behavior of HSH-carbon such as bulk modulus,Young’s modulus and shear modulus is comparable with that of T-carbon and much smaller than that of c-diamond,which suggests that HSH-carbon would be much easier to be processed than c-diamond in practice.

关键词： first-principles calculation novel carbon allotropes pentagonal ring

不同厂家热电池FeS_(2)-CoS_(2)复合正极材料的比较研究

在线全文

学校读者我要写书评

暂无评论

火工品 2025年第1期 77-82页

作者：冯帅张纯彭振国孙现忠刘岁鹏史紫阳杨军中国人民解放军93170部队西安710000 西安北方庆华机电有限公司陕西西安710025

为了加快热电池FeS_(2)-CoS_(2)复合正极材料的优化及应用,采用两种不同厂家生产的CoS_(2)作为导电剂添加到FeS_(2)中,制备出FeS_(2)-CoS_(2)复合正极材料及其单体电池,并对两种CoS_(2)原材料、FeS_(2)-CoS_(2)复合正极材料的微观形貌... 详细信息

为了加快热电池FeS_(2)-CoS_(2)复合正极材料的优化及应用,采用两种不同厂家生产的CoS_(2)作为导电剂添加到FeS_(2)中,制备出FeS_(2)-CoS_(2)复合正极材料及其单体电池,并对两种CoS_(2)原材料、FeS_(2)-CoS_(2)复合正极材料的微观形貌、粒度分布、X射线衍射分析以及单体电池的放电性能进行了研究。结果表明,广东产的FeS_(2)-CoS_(2)正极材料具有更均匀的微观分布和较少的小粒度粒子,湖南产的FeS_(2)-CoS_(2)正极材料更适合小电流放电应用,而广东产的FeS_(2)-CoS_(2)正极材料更适合于高功率放电。此外,将两种FeS_(2)-CoS_(2)正极材料应用于某型号热电池并进行高低温放电测试,结果表明广东产的FeS_(2)-CoS_(2)正极材料在放电性能上优于湖南产的FeS_(2)-CoS_(2)正极材料。

关键词：热电池正极材料 FeS_(2) CoS_(2) 微观形貌放电性能

同方期刊数据库

SAR target detection based on the optimal fractional Gabor spectrum feature

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2023年第2期21卷 55-64页

作者： Ling-Bing peng Yu-Qing Wang Ying-Pin Chen zhen-Ming peng School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu611731China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun130033China Institute of Optics and Electronics Chinese Academy of SciencesChengdu610209China School of Mathematical Sciences University of Electronic Science and Technology of ChinaChengdu611731China School of Physics and Information Engineering Minnan Normal UniversityZhangzhou363000China

In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target *** extending the fractional Gabor transform(FrGT)into two dimensions,the fractional time-frequency spectrum feature of an image can be *** the achievement process,we search for the optimal order and design the optimal window function to accomplish the two-dimensional optimal ***,the energy attenuation gradient(EAG)feature of the optimal time-frequency spectrum is extracted for high-frequency *** simulation results show the proposed algorithm has a good performance in SAR target detection and lays the foundation for recognition.

关键词： Optimal fractional Gabor transform(FrGT) Optimal order Synthetic aperture radar(SAR)target detection Time-frequency spectrum analysis

Assessment of the Biospheric Contribution to Surface Atmospheric CO2 Concentrations over East Asia with a Regional Chemical Transport Model

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2015年第3期32卷 287-300页

作者： KOU Xingxia ZHANG Meigen peng zhen WANG Yinghong State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences School of Atmospheric Sciences Nanjing University

A regional chemical transport model, RAMS-CMAQ, was employed to assess the impacts of biosphere–atmosphere CO2 exchange on seasonal variations in atmospheric CO2 concentrations over East Asia. Simulated CO2 concentrations were compared with observations at 12 surface stations and the comparison showed they were generally in good agreement. Both observations and simulations suggested that surface CO2 over East Asia features a summertime trough due to biospheric absorption, while in some urban areas surface CO2 has a distinct summer peak, which could be attributed to the strong impact from anthropogenic emissions. Analysis of the model results indicated that biospheric fluxes and fossil-fuel emissions are comparably important in shaping spatial distributions of CO2 near the surface over East Asia. Biospheric flux plays an important role in the prevailing spatial pattern of CO2 enhancement and reduction on the synoptic scale due to the strong seasonality of biospheric CO2 flux. The elevation of CO2 levels by the biosphere during winter was found to be larger than 5ppm in North China and Southeast China, and during summertime a significant depletion( 7 ppm) occurred in most areas,except for the Indo-China Peninsula where positive bioflux values were found.

关键词： CO2 regional transport modeling seasonal variation biospheric flux