检索结果-南通市图书馆

同方期刊数据库

Long-term Evolution of Solar Activity and Prediction of the Following Solar Cycles

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第3期24卷 194-204页

作者： pei-xin Luo Bao-Lin Tan National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

Solar activities have a great impact on modern high-tech systems,such as human aerospace activities,satellite communication and navigation,deep space exploration,and related scientific ***,studying the long-term evolution trend of solar activity and accurately predicting the future solar cycles are highly *** on the wavelet transform and empirical function fitting of the longest recorded data of the annual average relative sunspot number(ASN)series of 323 yr to date,this work decisively verifies the existence of the solar century cycles and confirms that its length is about 104.0 yr,and the magnitude has a slightly increasing trend on the timescale of several hundred *** on this long-term evolutionary trend,we predict solar cycles 25 and26 by using phase similar prediction *** for solar cycle 25,its maximum ASN will be about146.7±33.40,obviously stronger than solar cycle *** peak year will occur approximately in 2024,and the period will be about 11±1 *** for solar cycle 26,it will start around 2030,and reach its maximum between2035 and 2036,with maximum ASN of about 133.0±3.200,and period of about 10 yr.

关键词： Sun activity-Sun evolution-(Sun) sunspots-methods data analysis

Spacelike Framed Curves with Lightlike Components and Singularities of Their Evolutes and Focal Surfaces in Minkowski 3-space

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第6期40卷 1521-1532页

作者： Peng Cheng LI Dong He pei xin ZHAO School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024P.R.China Department of Mathematics Harbin Institute of TechnologyWeihai 264209P.R.China School of Mathematics and Statistics Qingdao UniversityQingdao 266071P.R.China

In this paper,we define the evolute and focal surface of a spacelike framed curve with lightlike components in Minkowski *** is a generalization of the previous results of regular spacelike curves,since singularities are allowed in the original spacelike curves studied by spacelike framed curves with lightlike ***,we show a new geometric invariant to characterise singularities of the focal ***,the classification theorem and recognition theorem for the singularities of the focal surface in generic are also given.

关键词： Evolutes focal surfaces spacelike framed curves singularities

Principal components of nuclear mass models

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： xin-Hui wu Pengwei Zhao Department of Physics Fuzhou UniversityFuzhou 350108China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

Graph neural network-based scheduling for multi-UAV-enabled communications in D2D networks

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 45-52页

作者： pei Li Lingyi Wang Wei wu Fuhui Zhou Baoyun Wang Qihui wu Nanjing University of Posts and Telecommunications Nanjing210023China Nanjing University of Aeronautics and Astronautics Nanjing210016China

In this paper,we jointly design the power control and position dispatch for Multi-Unmanned Aerial Vehicle(UAV)-enabled communication in Device-to-Device(D2D)*** objective is to maximize the total transmission rate of Downlink Users(DUs).Meanwhile,the Quality of Service(QoS)of all D2D users must be *** comprehensively considered the interference among D2D communications and downlink *** original problem is strongly non-convex,which requires high computational complexity for traditional optimization *** to make matters worse,the results are not necessarily globally *** this paper,we propose a novel Graph Neural Networks(GNN)based approach that can map the considered system into a specific graph structure and achieve the optimal solution in a low complexity ***,we first construct a GNN-based model for the proposed network,in which the transmission links and interference links are formulated as vertexes and edges,***,by taking the channel state information and the coordinates of ground users as the inputs,as well as the location of UAVs and the transmission power of all transmitters as outputs,we obtain the mapping from inputs to outputs through training the parameters of *** results verified that the way to maximize the total transmission rate of DUs can be extracted effectively via the training on ***,it also shows that the performance of proposed GNN-based method is better than that of traditional means.

关键词： Unmanned aerial vehicle D2 Dcommunication Graph neural network Power control Position planning

Polarization engineering in porous organic polymers for charge separation efficiency and its applications in photocatalytic aerobic oxidations

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

Science China Chemistry 2024年第3期67卷 1000-1007页

作者： Kun wu pei-Wen Cheng xin-Yi Liu Ji Zheng Xiao-Wei Zhu Mo Xie Puxin Weng Weigang Lu Dan Li College of Chemistry and Materials Science Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou 510632China Guangdong Rare Earth Photofunctional Materials Engineering Technology Research Center School of Chemistry and EnvironmentJiaying UniversityMeizhou 514015China

Photocatalytic aerobic oxidation reactions are largely governed by the efficiency of charge separation and subsequent reactive oxygen species(ROS) generation. Herein, we report a polarization engineering strategy to promote the charge separation and ROS generation efficiency by substituting the benzene unit with furan/thiophene in porous organic polymers(POPs). Benefiting from the extent of local polarization, the thiophene-containing POP(JNU-218) exhibits the best photocatalytic performance in aerobic oxidation reactions, with a yield much higher than those for the furan-containing POP(JNU-217) and the benzenecontaining POP(JNU-216). Experimental studies and theoretical calculations reveal that the increase of local polarization can indeed reduce the exciton binding energy, and therefore facilitate the separation of electron-hole pairs. This work demonstrates a viable strategy to tune charge separation and ROS generation efficiency by modulating the dipole moments of the building blocks in porous polymeric organic semiconductors.

关键词： porous organic polymer local polarization photocatalytic aerobic oxidation charge separation reactive oxygen species exciton binding energy

同方期刊数据库

Successful management of severe hypoglycemia induced by total parenteral nutrition in patients with hepatocellular injury: Three cases reports

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第1期12卷 157-162页

作者： Ling-Zhi Fang Hui-xin Jin Na Zhao Yu-pei wu Ying-Qin Shi Department of Pharmacy Hebei Key Laboratory of Clinical PharmacyHebei General HospitalShijiazhuang 050051Hebei ProvinceChina

BACKGROUND Glucose imbalance is common in total parenteral nutrition(TPN).Hypoglycemia seems to be less frequent than hyperglycemia,but it influences the clinical outcome to a greater ***,it should be effectively prevented and ***,there is no relevant report on how to treat hypoglycemia caused by TPN in patients with liver cell *** SUMMARY We present three patients with liver cell injury who developed severe hypo-glycemia during or after TPN *** causes of severe hypoglycemia and glucose-raising strategies were *** to the physiological charac-teristics of the hepatocellular injury,the ratio of nutrition components prescribed in TPN was appropriately adjusted for the three *** simultaneously reduced the dose of insulin and fat emulsion,and increased the dose of glucose in *** blood glucose level was restored to normal range and clinical symptoms were *** When hypoglycemia occurs during or after TPN in patients with hepatocellular injury,physicians need to simultaneously reduce insulin and fat emulsion,and increase glucose,and correct severe hypoglycemia in time to reduce its adverse consequences.

关键词： Total parenteral nutrition Hepatocellular injury Severe hypoglycemia Treatment Causes Case report

Generalized load graphical forecasting method based on modal decomposition

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

Global Energy Interconnection 2024年第2期7卷 166-178页

作者： Lizhen wu peixin Chang Wei Chen Tingting pei College of Electrical and Information Engineering Lanzhou University of TechnologyLanzhou 730050P.R.China School of Electrical Data Engineering University of Technology SydneyNSW2007Australia

In a“low-carbon”context,the power load is affected by the coupling of multiple factors,which gradually evolves from the traditional“pure load”to the generalized load with the dual characteristics of“load+power supply.”Traditional time-series forecasting methods are no longer suitable owing to the complexity and uncertainty associated with generalized *** the perspective of image processing,this study proposes a graphical short-term prediction method for generalized loads based on modal ***,the datasets are normalized and feature-filtered by comparing the results of Xtreme gradient boosting,gradient boosted decision tree,and random forest ***,the generalized load data are decomposed into three sets of modalities by modal decomposition,and red,green,and blue(RGB)images are generated using them as the pixel values of the R,G,and B *** generated images are diversified,and an optimized DenseNet neural network was used for training and ***,the base load,wind power,and photovoltaic power generation data are selected,and the characteristic curves of the generalized load scenarios under different permeabilities of wind power and photovoltaic power generation are obtained using the density-based spatial clustering of applications with noise *** on the proposed graphical forecasting method,the feasibility of the generalized load graphical forecasting method is verified by comparing it with the traditional time-series forecasting method.

关键词： Load forecasting Generalized load Image processing DenseNet Modal decomposition

Iron-Catalyzed Reductive C(aryl)—Si Cross-Coupling of Diaryl Ethers with Chlorosilanes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第6期42卷 578-584页

作者： pei Liu Baowei wu Xuefeng Cong Jie Kong School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi'anShaanxi710072 China Institute of Molecular Plus Department of Chemistry and Haihe Laboratory of Sustainable Chemical TransformationsTianjin University92 Weijin RoadTianjin300072 China

The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great ***,we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis,which constitutes an efficient protocol for the synthesis of a range of functionalized *** combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes,allowing their cross-coupling in a reductive *** low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed,which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o-amide auxiliary.

关键词： Cross-coupling Diaryl ethers Chlorosilanes C—O bond cleavage Iron catalyst 3d transition metals Selectivity Regioselectivity

Dissipation-Driven Superradiant Phase Transition of a Two-Dimensional Bose-Einstein Condensate in a Double Cavity

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

Chinese Physics Letters 2024年第6期41卷 44-48页

作者： Bo-Hao wu xin-xin Yang Yu Chen Wei Zhang Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China Graduate School of China Academy of Engineering Physics Beijing 100193China Beijing Academy of Quantum Information Sciences Beijing 100193China

We study superradiant phase transitions in a hybrid system of a two-dimensional Bose–Einstein condensate of atoms and two cavities arranged with a tilt *** adjusting the loss rate of cavities,we map out the phase diagram of steady states within a mean field *** is found that when the loss rates of the two cavities are different,superradiant transitions may not occur at the same time in the two cavities.A first-order phase transition is observed between the states with only one cavity in superradiance and both in *** the case that both cavities are superradiant,a net photon current is observed flowing from the cavity with small decay rate to the one with large decay *** photon current shows a non-monotonic dependence on the loss rate difference,owing to the competition of photon number difference and cavity field phase *** findings can be realized and detected in experiments.

关键词： Einstein transitions decay