检索结果-南通市图书馆

Multiple recollisions in nonsequential double ionization below the recollision-ionization threshold

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第12期30卷 392-398页

作者： xiao-meng ma Ai-Hong Tong Zhuo Wang Chun-Yang Zhai Department of Physics and Mechanical&Electrical Engineering Hubei University of EducationWuhan 430205China Institute of Optoelectronic materials and Components Hubei University of EducationWuhan 430205China College of Physics and Electronic Engineering Xinyang Normal UniversityXinyang 464000China

By using the three-dimensional classical ensemble model,the recollision dynamics in nonsequential double ionization(NSDI)of Ar by 780-nm laser pulses at(6-1.2)×10^(14)W/cm^(2) was extensively *** revealed the picture of multiplerecollision in the double ionization events at the laser intensity region below the recollision-ionization *** tracing the NSDI trajectories,it was found that the contribution of these multiple-recollision events increases as the laser intensity *** this low intensity region,many multiple-recollision induced NSDI trajectories occur through the doubly excited *** decay speed of the doubly excited state decreases with the decreasing laser intensity.

关键词： nonsequential double ionization multiple recollision

Application of radioactive iodine-125 microparticles in hepatocellular carcinoma with portal vein embolus

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第7期16卷 2023-2030页

作者： Peng meng Ji-Peng ma xiao-Fei Huang Kang-Le Zhang The Fourth Department of Oncology Yantai Hospital of Traditional Chinese MedicineYantai 264001Shandong ProvinceChina Department of Medical Services Yantai Hospital of Traditional Chinese MedicineYantai 264001Shandong ProvinceChina Department of Hepatobiliary Surgery The First Affiliated Hospital of Sun Yatsen UniversityGuangzhou 510062Guangdong ProvinceChina The Third Department of Oncology Yantai Hospital of Traditional Chinese MedicineYantai 264001Shandong ProvinceChina

BACKGROUND Radioactive iodine-125(125I)microparticle therapy is a new type of internal radiation therapy that has shown unique advantages in the treatment of malignant tumors,especially hepatocellular *** with hepatocellular carcinoma frequently experience portal vein embolism,which exacerbates the difficulty and complexity of treatment.125I particles,used in local radiotherapy,can directly act on tumor tissue and reduce damage to surrounding healthy *** retrospective analysis,this study discussed the efficacy and safety of radioactive 125I particles in portal vein embolization patients with hepatocellular carcinoma in order to provide more powerful evidence supporting clinical *** To investigate the effect of transcatheter arterial chemoembolization combined with portal vein 125I particle implantation in the treatment of primary liver cancer patients with portal vein tumor thrombus and its influence on liver *** The clinical data of 96 patients with primary liver cancer combined with portal vein tumor thrombus admitted to our hospital between January 2020 and December 2023 were retrospectively ***-two patients received treatment with transcatheter arterial chemoembolization and implantation of 125I particles in the portal vein(combination group),while 44 patients received treatment with transcatheter arterial chemoembolization alone(control group).The therapeutic effects on tumor lesions,primary liver cancer,and portal vein tumor embolisms were compared between the two *** in relevant laboratory indexes before and after treatment were *** t test was used to compare the measurement data between the two groups,and the χ^(2) test was used to compare the counting data between *** The tumor lesion response rate in the combination group(59.62%vs 38.64%)and the response rate of patients with primary liver cancer complicated with portal vein tumor thrombus(80.77%vs 59.09%)were signi

关键词： Radioactive iodine-125 Hepatocellular carcinoma Transcatheter arterial chemoembolization Portal vein embolus Retrospective study

Efficient removal of Cr(VI) by polydopamine-modified lignin from aqueous solution: Batch and XAFS studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water Science and Engineering 2024年第1期17卷 51-61页

作者： xiao-jie Guo Wei-kang Fu Jing-yuan ma Bo-jun Xi Chen Wang meng-yao Guan College of materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China College of Textile and Garment Shaoxing UniversityShaoxing 312000China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

Lignocellulose has the potential to become a bio-based adsorbent due to its biodegradability and *** this study,a novel polydopamine functionalized-lignin(lignin@PDA),prepared via self-polymerization of dopamine(PDA)on lignin,was used as a bio-based adsorbent for rapid scavenging of hexavalent chromium(Cr(VI)).The morphology,functional groups,crystalline structure,and chemical composition of lignin@PDA were characterized with a scanning electron microscope-energy dispersive spectrometer,Fourier transform infrared spectroscopy,X-ray diffraction,and X-ray photoelectron *** Cr(VI)adsorption process of lignin@PDA was studied using batch experiments as a function of pH,ionic strength,adsorbent dose,and contact time at room *** adsorption rate of lignin@PDA was five times greater than that of the unmodified lignin,with a maximum adsorption capacity of 102.6 mg/g in an acidic *** adsorption of Cr(VI)on lignin@PDA fit the pseudo-secondorder equation and the Freundlich model,indicating that the adsorption process was mainly dominated by chemisorption and surface *** thermodynamic parameters showed that adsorption of Cr(VI)on lignin@PDA was an endothermic and spontaneous *** X-ray absorption fine structure results showed that sorption and reduction of Cr(VI)into Cr(II)occurred simultaneously on ***,PDA coating not only improved the reactivity of lignin but also promoted the complete reduction of Cr(VI)by *** to these results,polydopamine functionalized-lignin is a promising bio-based adsorbent for immobilization of Cr(VI)from wastewater.

关键词： Lignin Polydopamine Hexavalent chromium EXAFS Adsorption mechanism

Research on casing deformation prevention technology based on cementing slurry system 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

Petroleum Science 2024年第2期21卷 1231-1240页

作者： Yan Yan meng Cai Wen-Hai ma xiao-Chuan Zhang Li-Hong Han Yong-Hong Liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi meng Zhi-Ming ma Academy of mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

A new method for evaluating wedges of steel plates and strips

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1719-1735页

作者： xiao-bao ma xiao-xin ma Tao Wang Zhong-kai Ren Yu-cheng Ren College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Ministry of Education Engineering Research Center of Advanced Metal Composite Forming Technology and Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina China National Heavy machinery Research Institute Co. Ltd.Xi'an 710018ShaanxiChina Faculty of Mechanical Engineering Hebei University of ArchitectureZhangjiakou 075000HebeiChina

To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was ***,an integral model for the discrete thickness values of the cross-section profiles was *** discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of *** three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and *** results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.

关键词： Steel plate and strip Wedge Two-point method Double-centroid method Reliability

Two-stage aging treatment to accelerate aging kinetics without impairing strength in B_4C/7A04Al composite

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(Technological Sciences) 2024年第8期67卷 2485-2492页

作者： CHEN YunTao ma GuoNan ZHU ShiZe WANG Dong xiao BoLv ma ZongYi Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Centre of Excellence for Advanced materials Dongguan 523808China

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage(SS) aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃ + 160℃ two-stage(TS) aging treatment was proposed on a B_4C/7A04Al composite fabricated via powder metallurgy(PM) technology, which could acquire similar peak-aging strength but only took about 15% of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′ phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B_4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B_4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B_4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

关键词： aluminum matrix composites aging treatment powder metallurgy mechanical properties precipitation

Insulation Design Rule for a Spacer in SF_(6)/N_(2)-filled DC Gas Insulated Apparatus

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 727-735页

作者： Hongyang Zhou Guoming ma meng Zhang Cong Wang Youping Tu Chengrong Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

A recurring challenge of a DC SF_(6)/N_(2)-filled GIS/GIL apparatus is the charge accumulation at DC *** conventional design rules and knowledge of AC spacers may not be applicable for this new type of apparatus.A novel design rule is proposed considering the effect of accumulated charge on the threshold of electric field strength being resistant to the superposed voltage.A surface charge accumulation simulation model is introduced,and the key parameters in the simulation model are *** addition,an experimental platform for a 100 kV spacer flashover test is *** flashover tests under superimposed voltage with opposing polarities are carried out,and the withstanding voltage of the spacer is ***,based on the proposed model,the threshold of the surface electric field strength(tangential component)on the DC spacer in SF_(6)/N_(2) mixed gases is *** a reliable insulation design of a DC GIS/GIL apparatus filled with 0.7 MPa SF_(6)/N_(2),the threshold of surface electric field strength on the DC spacer is 12 kV/*** insulation design rule can be referenced in the design of a high-voltage DC SF_(6)/N_(2)-filled GIS/GIL apparatus.

关键词： Charge accumulation DC spacer flashover voltage SF_(6)/N_(2) threshold of surface electric field strength

Optimal search path planning of UUV in battlefeld ambush scene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 541-552页

作者： Wei Feng Yan ma Heng Li Haixiao Liu Xiangyao meng Mo Zhou Naval Research Institute Beijing100161China

Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean ***,by establishing these mathematical models of ocean current environment,target movement,and sonar detection,the probability calculation methods of single UUV searching target and multiple UUV cooperatively searching target are given ***,based on the Hybrid Quantum-behaved Particle Swarm Optimization(HQPSO)algorithm,the path with the highest target search probability is ***,through simulation calculations,the influence of different UUV parameters and target parameters on the target search probability is analyzed,and the minimum number of UUVs that need to be deployed to complete the ambush task is demonstrated,and the optimal search path scheme is *** method proposed in this paper provides a theoretical basis for the practical application of UUV in the future combat.

关键词： Battlefield ambush Optimal search path planning UUV path Planning Probability of cooperative search