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International Journal of Mining Science and Technology 2024年第6期34卷 799-819页

作者： wei Yao Shuai Wang Bangbiao Wu Ying xu Kaiwen Xia State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300072China China Railway Design Corporation Tianjin 300308China Institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China

Understanding the effects of microwave irradiation and thermal treatment on the dynamic compression and fragmentation properties of rocks is essential to quantify energy consumption in rock *** this study,Fangshan granite(FG)specimens were exposed to microwave irradiation and heat *** damage of FG specimens induced by these two methods was compared using X-ray CT scanning and ultrasonic wave *** temperatures of FG after microwave irradiation and thermal treatment were effectively evaluated using a newly proposed technique.A novelty method for precisely determining the geometric features of fragments is developed to estimate the fragmentation ***,the dynamic uniaxial compressive strength(UCS),the dynamic fragmentation characteristics,and the fragmentation energy of FG after these two pretreatment methods can be reasonably *** noticeable distinction of loading rate effect on the dynamic UCS of FG between these two pretreatment methods is first observed.A relationship is established between the dynamic UCS and the damage induced by microwave irradiation and heat ***,fragmentation energy fan analysis is introduced to accurately compare the fragmentation properties of FG after two pretreatment methods in dynamic compression tests.

关键词： Fangshan granite Dynamic experiments Microwave irradiation Thermal treatment Loading rate Fragmentation

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

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Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng Sheng-Jie wei Guang-Qing Zhang Da-wei Zhou Chuang-Chao xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 10 Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1) this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01%.(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 100 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Intravitreal conbercept injection with panretinal photocoagulation for high-risk proliferative diabetic retinopathy with vitreous hemorrhage

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1066-1072页

作者： Yao xu Qing Ye wei Shen Department of Ophthalmology the Fourth Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Ophthalmology Suzhou Kowloon HospitalShanghai Jiao Tong University School of MedcineSuzhou 215000Jiangsu ProvinceChina Department of Ophthalmology the First Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina

AIM:To assess the clinical efficacy and safety of combining panretinal photocoagulation(PRP)with intravitreal conbercept(IVC)injections for patients with high-risk proliferative diabetic retinopathy(HR-PDR)complicated by mild or moderate vitreous hemorrhage(VH),with or without diabetic macular edema(DME).METHODS:Patients diagnosed with VH with/without DME secondary to HR-PDR and received PRP combined with IVC injections were recruited in this retrospective *** establishing the patient’s diagnosis,an initial IVC was performed,followed by prompt administration of *** cases who significant bleeding persisted and impeded the laser operation,IVC was sustained before supplementing with *** the completion of PRP,patients were meticulously monitored for a minimum of six *** therapy and IVC injections were judiciously adjusted based on fundus fluorescein angiography(FFA)*** effect and the incidence of adverse events were ***:Out of 42 patients(74 eyes),29 were male and 13 were female,with a mean age of 59.17±12.74y(33-84y).The diabetic history was between 1wk and 26y,and the interval between the onset of visual symptoms and diagnosis of HR-PDR was *** affected eye received 2.59±1.87(1-10)IVC injections and underwent 5.5±1.02(4-8)sessions of *** these,68 eyes received PRP following 1 IVC injection,5 eyes after 2 IVC injections,and 1 eye after 3 IVC *** absorption of VH was observed in all 74 eyes 5-50wk after initial treatment,with resolution of DME in 51 eyes 3-48wk after initial treatment.A newly developed epiretinal membrane was noted in one *** acuity significantly improved in 25 *** complications such as glaucoma,retinal detachment,or endophthalmitis were ***:The study suggests that the combination of PRP with IVC injections is an effective and safe modality for treating diabetic VH in patients with HR-PDR.

关键词： conbercept panretinal photocoagulation high-risk proliferative diabetic retinopathy vitreous hemorrhage

Rotating Massive Strangeon Stars and X-Ray Plateau of Short GRBs

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Research in Astronomy and Astrophysics 2024年第3期24卷 47-57页

作者： Xi-Yan Yang Xiao-Yu Lai wei-wei Tan Ren-Xin xu School of Physics and Optoelectronic Engineering Yangtze UniversityJingzhou 434023China Research Center for Astronomy Hubei University of EducationWuhan 4300205China Key Laboratory of Quark and Lepton Physics Central China Normal UniversityMinistry of EducationWuhan 430079China School of Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

Strangeon stars,which are proposed to describe the nature of pulsar-like compact stars,have passed various observational *** maximum mass of a non-rotating strangeon star could be high,which implies that the remnants of binary strangeon star mergers could even be long-lived massive strangeon *** study rigidly rotating strangeon stars in the slowly rotating approximation,using the Lennard-Jones model for the equation of *** can significantly increase the maximum mass of strangeon stars with unchanged baryon numbers,enlarging the mass-range of long-lived strangeon *** spin-down after merger,the decrease of radius of the remnant will lead to the release of gravitational *** into account the efficiency of converting the gravitational energy luminosity to the observed X-ray luminosity,we find that the gravitational energy could provide an alternative energy source for the plateau emission of X-ray *** fitting results of X-ray plateau emission of some short gamma-ray bursts suggest that the magnetic dipole field strength of the remnants can be much smaller than that of expected when the plateau emission is powered only by spin-down luminosity of magnetars.

关键词： dense matter-(stars) pulsars general-(stars) gamma-ray burst general

Molecular dynamics simulation study of nitrogen vacancy color centers prepared by carbon ion implantation into diamond

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Nanotechnology and Precision Engineering 2024年第3期7卷 71-78页

作者： wei Zhao Zongwei xu Pengfei Wang Hanyi Chen State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

Nitrogen vacancy(NV)color centers in diamond have useful applications in quantum sensing andﬂuorescent *** can be gen-erated experimentally by ion implantation,femtosecond lasers,and chemical vapor ***,there is a lack of studies of the yield of NV color centers at the atomic *** the molecular dynamics simulations described in this paper,NV color centers are pre-pared by ion implantation in diamond with pre-doped nitrogen and subsequent *** differences between the yields of NV color centers produced by implantation of carbon(C)and nitrogen(N)ions,respectively,are *** is found that C-ion implantation gives a greater yield of NV color centers and superior location *** effects of different pre-doping concentrations(400–1500 ppm)and implantation energies(1.0–3.0 keV)on the NV color center yield are analyzed,and it is shown that a pre-doping concentra-tion of 1000 ppm with 2 keV C-ion implantation can produce a 13%yield of NV color centers after 1600 K annealing for 7.4 ***,a brief comparison of the NV color center identiﬁcation methods is presented,and it is found that the error rate of an analysis utiliz-ing the identify diamond structure coordination analysis method is reduced by about 7%compared with conventional identiﬁcation+methods.

关键词： NV color center Ion implantation Molecular dynamics(MD)simulation Yield enhancement

Adaptive Resource Allocation Algorithm for 5G Vehicular Cloud Communication

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Computers, Materials & Continua 2024年第8期80卷 2199-2219页

作者： Huanhuan Li Hongchang wei Zheliang Chen Yue xu School of Mathematics and Computer Sciences Nanchang UniversityNanchang330031China Department of Electrical Engineering Jiangxi Vocational College of Mechanical&Electrical TechnologyNanchang330013China Kehua Data Co. Ltd.Xiamen361006China

The current resource allocation in 5G vehicular networks for mobile cloud communication faces several challenges,such as low user utilization,unbalanced resource allocation,and extended adaptive allocation *** propose an adaptive allocation algorithm for mobile cloud communication resources in 5G vehicular networks to address these *** study analyzes the components of the 5G vehicular network architecture to determine the performance of different *** is ascertained that the communication modes in 5G vehicular networks for mobile cloud communication include in-band and out-of-band ***,this study analyzes the single-hop and multi-hop modes in mobile cloud communication and calculates the resource transmission rate and bandwidth in different communication *** study also determines the scenario of one-way and two-way vehicle lane cloud communication network connectivity,calculates the probability of vehicle network connectivity under different mobile cloud communication radii,and determines the amount of cloud communication resources required by vehicles in different lane *** on the communication status of users in 5G vehicular networks,this study calculates the bandwidth and transmission rate of the allocated channels using Shannon’s *** determines the adaptive allocation of cloud communication resources,introduces an objective function to obtain the optimal solution after allocation,and completes the adaptive allocation *** experimental results demonstrate that,with the application of the proposed method,the maximum utilization of user communication resources reaches approximately 99%.The balance coefficient curve approaches 1,and the allocation time remains under 2 *** indicates that the proposed method has higher adaptive allocation efficiency.

关键词： 5G vehicular networks mobile cloud communication resource allocation channel capacity network connectivity communication radius objective function

Mapping multiple phases in curcumin binary solid dispersions by fluorescence contrasting

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Chinese Chemical Letters 2024年第9期35卷 266-272页

作者： Ying xu Chengying Shen Hailong Yuan wei Wu Key Laboratory of Smart Drug Delivery of MOE School of PharmacyFudan UniversityShanghai 201203China Center for Medical Research and Innovation Shanghai Pudong HospitalFudan University Pudong Medical CenterShanghai 201399China Department of Pharmacy Air Force Medical CenterPLABeijing 100142China Jiangxi Provincial People’s Hospital The First Affiliated Hospital of Nanchang Medical CollegeNanchang 330006China

The microphases and miscibility in binary curcumin(Cur)solid dispersions(SDs)with amorphous polyvinylpyrrolidone K30(PVP K30)and semi-crystalline poloxamer(P407)and poly(ethylene glycol)6000(PEG6000)as carriers were investigated by fluorescence contrasting utilizing confocal laser scanning microscopy.A super sensitive fluorophore P4 with typical aggregation-caused quenching properties was employed to stain the continuous polymer phases and contrasted with the autofluorescence of the model drug *** addition,differential scanning calorimetry(DSC)and powder X-ray diffraction(PXRD)were utilized to assist in explanation of the fluorescence *** all three SD systems,there is always a homogenous polymer phase stained by P4 and it is difficult to adulterate Cur crystals by ***-enriched rather than polymer-enriched domains could be *** the Cur-PVP K30 system,Cur exists in an amorphous form at a Cur loading level of 50%and below,while Cur crystallines phase out and continuously grow with the increase of Cur loading from 60%to 90%.The phase behaviors in the Cur-P407 and Cur-PEG 6000 systems are similar but with minor *** both systems,Cur phases out as clusters of drug-enriched domains at a loading level of 20%and below,which however cannot be correlated with crystallization,as evidenced by both DSC and *** is a transition from an amorphous to a crystalline state from 20%to 30%Cur loading,above which Cur crystallines can be *** is interesting that a co-mix phase of both Cur-and PEG 6000-enriched domains can be identified at Cur loading levels of 10%and *** together,it is concluded that contrasting Cur autofluorescence with the signals of P4 proves to be a functional strategy to reveal multiple phases in the binary SD systems investigated.

关键词： Solid dispersion Curcumin PEG PVP Poloxamer Fluorescence Environment-responsive Confocal laser scanning microscopy

Charge-asymmetry Fe_(1)Cu single-atom alloy catalyst for efficient oxygen reduction reaction

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Nano Research 2024年第6期17卷 4702-4710页

作者： xudong Niu Jian wei Dongyao xu Jiajing Pei Rui Sui School of Chemical&Environmental Engineering China University of Mining and TechnologyBeijing 100083China Institute of Water Ecology and Environment Chinese Research Academy of Environmental SciencesBeijing 100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China

The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air *** promising way is to develop Fe single-atom ***,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR ***,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was *** characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast ***,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V *** hydrogen electrode(RHE),outperforming its counterparts in the ***,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent *** work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.

关键词： Fe_(1)Cu single-atom alloy(SAA) electrocatalysis oxygen reduction reaction charge-asymmetry

Surface roughness classification using light scattering matrix and deep learning

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Science China(Technological Sciences) 2024年第2期67卷 520-535页

作者： SUN Hao TAN wei RUAN YiXiao BAI Long xu JianFeng State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Wuhan Digital Design and Manufacturing Innovation Center Co. LtdWuhan 430074China

High-quality optical components have been widely used in various applications;thus,extremely high beam quality is ***,surface roughness is a key indicator of the surface *** this study,the angular distribution of light scattering field intensity was obtained for surfaces having different roughness profiles based on the finite difference time domain(FDTD)method,and the results were compared with those obtained using the generalized Harvey-Shack(GHS)*** was shown that the FDTD approach can be used for an accurate simulation of the scattered field of a rough surface,and the superposition of results obtained from many surfaces that have the same roughness level was in good agreement with the result given by the analytic GHS model.A light scattering matrix(LSM)method was proposed based on the FDTD simulation results that could obtain rich surface roughness *** classification effect of LSM was compared with that of the single-incidence scattering distribution(SISD)based on a ResNet-50 deep learning *** classification accuracy of the model trained with the LSM dataset was obtained as 95.74%,which was 23.40%higher than that trained using the SISD ***,the effects of different noise types and filtering methods on the classification performance were analyzed,and the LSM was also shown to improve the robustness and generalizability of the trained surface roughness ***,the proposed LSM method has important implications for improving the data acquisition scheme of current light scattering measurement systems,and it also has the potential to be used for detection and characterization of surface defects of optical components.

关键词： surface roughness FDTD simulation GHS theory deep learning light scattering matrix

Review on the recent progress of nearly zero energy building frontiers in China

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Science China(Technological Sciences) 2024年第9期67卷 2620-2636页

作者： LYU YanJie xu wei ZHANG ShiCong SUN DeYu HOU YueBin China Academy of Building Research Beijing 100013China

Energy efficiency improvement in Chinese construction has progressed rapidly over the past two *** zero energy buildings(NZEBs),as an integrated solution for energy-efficient construction,have gained significant attention during China's 13th Five-Year Plan period,with continuous maturation of the technical *** this study,a research framework built upon the accomplishments of China's National Key Research and Development Program is developed,and an in-depth analysis of the most cutting-edge research is provided by thoroughly reviewing the work conducted *** NZEB in China has been categorized into three stages based on the characteristics of technological development:(1)definition and standards,(2)demonstration and promotion,and(3)cross-domain *** study discerns four noteworthy development trends by examining comprehensive data spanning the last decade from 100 NZEB and zero energy ***,a comprehensive analysis of essential technology advancements in line with these identified trends is *** issues and challenges arising from the increased application of renewable energy in the context of China's carbon peak and carbon neutrality goals have also been ***,based on this analysis,the challenges and corresponding suggestions for future research directions were proposed to help guide future studies exploring emerging trends in the NZEB field.

关键词： nearly zero energy building energy efficiency load flexibility heat pump renewable energy