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Observational appearances of hairy black holes in the framework of gravitational decoupling

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Communications in Theoretical Physics 2024年第8期76卷 103-117页

作者： Yizhi Liang xin lyu Jun Tao Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu 610065China

We investigate the observational appearance of static and spherically symmetric hairy black holes in the framework of gravitational decoupling with the weak energy condition(WEC). Two types of thin illumination conditions are studied: spherical accretion and disk accretion. As the hairy parameter increases, the size of the photon sphere and photon rings in both models decreases, and the overall luminosity attenuation becomes more pronounced. In spherical accretion, the luminosity of infalling accretion is significantly lower than that of stationary accretion. In disk accretion the luminosity of the black hole is contributed by direct emission, the lensing ring and the photon ring. Employing four types of astrophysical disk luminosity model,we investigate the appearance of halos and note that their luminosities do not superimpose when the source is on or beyond the innermost stable circular orbit.

关键词： hairy black hole shadow gravitational decoupling accretion disk

Prospects for the transformation and development of carbon storage in abandoned mines of coal enterprises from the perspective ofcarbon neutrality

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International Journal of Coal Science & Technology 2023年第3期10卷 24-40页

作者： xin lyu Tong Zhang Liang Yuan Juejing Fang State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China Institute of Energy Hefei Comprehensive National Science CenterHefei230031China

Under the carbon neutrality goal,coal enterprises must seek breakthroughs from abandoned mines,develop new resources in the new era,turn problems into countermeasures,and participate in the carbon emissions market,for contributing to the accomplishment of the national strategic goal of carbon *** this end,we investigated the relevant national policies and regulations to clarify the boundaries disclosed by the carbon information of enterprises,understood the development direction of carbon storage in abandoned mines,and clarified the transformation and development of carbon storage in aban-doned *** made a few suggestions:(1)China should learn from its past experience and other countries to develop the energy industry with Chinese characteristics and reform the economic system.(2)Coal enterprises must actively respond to the national carbon information disclosure policy,clarify their own responsibilities and carbon emission boundaries.(3)It is necessary to proactively obtain advanced knowledge and plan carbon storage pathways for abandoned mines.(4)Devel-opment problems of coal enterprises should be deduced using ***'dual carbon'goals should be achieved steadily step-by-step.(5)Three measures,*** the existing resource structure,coordinating the information of abandoned mines,and promoting the cultivation of scientific and technological talents.

关键词： Mining engineering Abandoned mines Carbon neutrality Carbon emission rights Carbon tax

Fundamental characteristics of gas hydrate-bearing sediments in the Shenhu area, South China Sea

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Frontiers in Energy 2021年第2期15卷 367-373页

作者： xin lyu Qingping LI Yang GE Junlong ZHU Shouwei ZHOU Qiang FU China National Offshore Oil Corporation Research Institute Co.Ltd Beijing 100028China State Key Laboratory of Natural Gas Hydrate Beijing100028China China National Offshore Oil Corporation Beijing 100021China

The basic physical properties of marine natural gas hydrate deposits are important to the understanding of seabed growth conditions, occurrence regularity, and occurrence environment of natural gas hydrates. A comprehensive analysis of the core samples of drilling pressure-holding hydrate deposits at a depth of 1310 m in the Shenhu area of the South China Sea was conducted. The experimental results indicate that the particle size in the hydrate sediment samples are mainly distributed in the range from 7.81 µm to 21.72 µm, and the average particle size decreases as the depth of the burial increases. The X-ray CT analytical images and surface characteristics SEM scan images suggest that the sediment is mostly silty clay. There are a large number of bioplastics in the sediment, and the crack inside the core may be areas of hydrate formation.

关键词： natural gas hydrate Shenhu area reservoirs characteristics

Assessing the severity of cotton Verticillium wilt disease from in situ canopy images and spectra using convolutional neural networks

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The Crop Journal 2023年第3期11卷 933-940页

作者： Xiaoyan Kang Changping Huang Lifu Zhang Mi Yang Ze Zhang xin lyu National Engineering Research Center of Satellite Remote Sensing Applications Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China xinjiang Production and Construction Corps Oasis Eco-Agriculture Key Laboratory College of AgricultureShihezi UniversityShihezi 832003XinjiangChina

Verticillium wilt(VW)is a common soilborne disease of *** occurs mainly in the seedling and bollopening stages and severely impairs the yield and quality of the *** and accurate identification and evaluation of VW severity(VWS)forms the basis of field cotton VW control,which has great significance to cotton *** VWS values are conventionally measured using in-field observations and laboratory test diagnoses,which require abundant time and professional *** and proximal sensing using imagery and spectrometry have great potential for this *** this study,we performed in situ investigations at three experimental sites in 2019 and 2021 and collected VWS values,in situ images,and spectra of 361 cotton *** estimate cotton VWS values at the canopy scale,we developed two deep learning approaches that use in situ images and spectra,*** the imagery-based method,given the high complexity of the in situ environment,we first transformed the task of healthy and diseased leaf recognition to the task of cotton field scene classification and then built a cotton field scenes(CFS)dataset with over 1000 images for each scene-unit *** performed pretrained convolutional neural networks(CNNs)training and validation using the CFS dataset and then used the networks after training to classify scene units for each *** results showed that the Dark Net-19 model achieved satisfactory performance in CFS classification and VWS values estimation(R^(2)=0.91,root-mean-square error(RMSE)=6.35%).For the spectroscopy-based method,we first designed a one-dimensional regression network(1D CNN)with four convolutional *** dimensionality reduction by sensitive-band selection and principal component analysis,we fitted the 1D CNN with varying numbers of principal components(PCs).The 1D CNN model with the top 20 PCs performed best(R^(2)=0.93,RMSE=5.77%).These deep learning-driven approaches offer the potential of assessing cro

关键词： Canopy scale Cotton verticillium wilt Deep learning Disease assessment In situ imagery In situ spectrometry

Optimization of tracheoesophageal fistula model established with Tshaped magnet system based on magnetic compression technique

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World Journal of Gastroenterology 2024年第16期30卷 2272-2280页

作者： Miao-Miao Zhang Jian-Qi Mao Lin-xin Shen Ai-Hua Shi xin lyu Jia Ma Yi lyu Xiao-Peng Yan Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Shaanxi Provincial Key Laboratory of Magnetic Medicine The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Zonglian College Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina National Local Joint Engineering Research Center for Precision Surgery&Regenerative Medicine The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Department of Pulmonary and Critical Care Medicine The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004Shaanxi ProvinceChina Department of Surgical Oncology Shaanxi Provincial People’s HospitalXi’an 710068Shaanxi ProvinceChina

BACKGROUND The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula(TEF),but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model *** designed a Tshaped magnet system to overcome these problems and verified its effectiveness via animal *** To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle *** Twelve beagles were randomly assigned to groups in which magnets of the Tshaped scheme(study group,n=6)or normal magnets(control group,n=6)were implanted into the trachea and esophagus separately under *** time,operation success rate,and accidental injury were *** operation,the presence and timing of cough and the time of magnet shedding were *** in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing,and gross specimens of TEFs were *** in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery,and gross specimens were *** size was measured in all animals,and then harvested fistula specimens were examined by hematoxylin and eosin(HE)and Masson trichrome *** The operation success rate was 100%for both *** time did not differ between the study group(5.25 min±1.29 min)and the control group(4.75 min±1.70 min;P=0.331).No bleeding,perforation,or unplanned magnet attraction occurred in any animal during the *** the early postoperative period,all dogs ate freely and were generally in good *** in the control group had severe cough after drinking water at 6-9 d after surgery.X-ray indicated that the magnets had entered the stomach,and gastroscopy showed TEF *** specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm±1.29 mm(range,3.52-6.56 mm).HE and Masson trichrome staining showed s

关键词： Magnetic surgery Magnetic compression technique Tracheoesophageal fistula Magnet Animal model Beagles

Local Government Debt,Sectoral Linkage and Resource Allocation Efficiency

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China Finance and Economic Review 2023年第2期12卷 28-48页

作者： xin lyu Wenlin Fu Rui Zhou School of Finance&Public Administration Shanghai Lixin University of Accounting and Finance School of Public Finance and Taxation Zhejiang University of Finance&Economics School of Humanities Shanghai University of Finance and Economics

Increasing the efficiency of resource allocation is the basis and guarantee for boosting high-quality economic *** on the panel data of Chinese industrial enterprises and cities from 2008 to 2013,this paper studies the influence of infrastructure construction demand shocks represented by local government debt expansion on the efficiency of sectoral resource allocation from the perspective of sectoral *** to the empirical findings,local government debt significantly reduces the resource allocation efficiency of manufacturing sector that is highly related to infrastructure *** conclusion is still tenable after the robustness test using the simulated local government debt as an instrumental *** mechanism tests show that there are two reasons for the decline of the efficiency of resource allocation in manufacturing sector that is highly related to infrastructure ***,more product demands and investments brought by the expansion of local government debt flow to less productive enterprises in the ***,resource misallocation reduces the probability of high-productivity enterprises entering the market and low-productivity enterprises exiting the market,and the effect is more prominent in cities with high dependence on state-owned enterprises and high pressure on officials to be *** to this study,the performance management of local government debt should be further strengthened,and particular attention should be paid to the influence of local government debt on enterprise investment and financing crowding out and resource misallocation.

关键词： local government debt infrastructure construction sectoral linkage resource misallocation

Enhancing thermoelectric performance of p-type SnTe through manipulating energy band structures and decreasing electronic thermal conductivity

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Rare Metals 2024年第7期43卷 3232-3241页

作者： xin Qian Hao-Ran Guo Jia-xin lyu Bang-Fu Ding xing-Yuan San Xiao Zhang Jiang-Long Wang Shu-Fang Wang Hebei Key Lab of Optic-Electronic Information and Materials College of Physics Science and TechnologyHebei UniversityBaoding 071002China College of Electron and Information Engineering Hebei UniversityBaoding 071002China Research Institute for Frontier Science Beihang UniversityBeijing100191China

SnTe has received considerable attention as an environmentally friendly alternative to the representative thermoelectric material of ***,excessive hole carrier concentration in SnTe results in an extremely low Seebeck coefficient and high thermal conductivity,which makes it exhibit relatively inferior thermoelectric *** this work,the thermoelectric performance of p-type SnTe is enhanced through regulating its energy band structures and reducing its electronic thermal conductivity by combining Bi doping with CdSe ***,the carrier concentration of SnTe is successfully suppressed via Bi doping,which significantly decreases the electronic thermal ***,the convergence and flattening of the valence bands by alloying CdSe effectively improves the effective mass of SnTe while restraining its carrier ***,a maximum figure of merit(ZT) of~ 0.87 at 823 K and an average ZT of~ 0.51 at 300-823 K have been achieved in Sn_(0.96)Bi_(0.04)Te-5%*** results indicate that decreasing the electronic thermal conductivity is an effective means of improving the performance of thermoelectric materials with a high carrier concentration.

关键词： Thermoelectric materials SnTe Energy band structure Electronic thermal conductivity ZT value

Analysis of physical properties of gas hydrate-bearing unconsolidated sediment samples from the ultra-deepwater area in the South China Sea

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Frontiers in Energy 2022年第3期16卷 509-520页

作者： xin lyu Qingping Li Yang Ge Min Ouyang Hexing Liu Qiang Fu Junlong Zhu Shouwei Zhou China National Offshore Oil Corporation Research Institute Co.Ltd. Beijing 100028China State Key Laboratory of Natural Gas Hydrate Beijing100028China Zhanjiang Branch of China National Offshore Oil Corporation(CNOOC)Limited Zhanjiang524057China China National Offshore Oil Corporation(CNOOC) Beijing100021China

Marine natural gas hydrate has recently attracted global attention as a potential new clean energy source. Laboratory measurements of various physical properties of gas hydrate-bearing marine sediments can provide valuable information for developing efficient and safe extraction technology of natural gas hydrates. This study presents comprehensive measurement results and analysis of drilled hydrate-bearing sediments samples recovered from Qiongdongnan Basin in the South China Sea. The results show that the gas hydrate in the core samples is mainly methane hydrate with a methane content of approximately 95%, and the other components are ethane and carbon dioxide. The saturation of the samples fluctuates from 2%–60%, the porosity is approximately 38%–43%, and the water content is approximately 30%–50%, which indicate that high water saturation means that timely drainage should be paid attention to during hydrate extraction. In addition, the median diameter of the sediment samples is mainly distributed in the range of 15 to 34 µm, and attention should be paid to the prevention and control of sand production in the mining process. Moreover, the thermal conductivity is distributed in the range of 0.75 to 0.96 W/(m·K) as measured by the flat plate heat source method. The relatively low thermal conductivity of hydrates at this study site indicates that a combined approach is encouraged for natural gas production technologies. It is also found that clay flakes and fine particles are attached to the surface of large particles in large numbers. Such characteristics will lead to insufficient permeability during the production process.

关键词： natural gas hydrates physical properties analysis hydrate-bearing sediments

Design and Realization of Schottky Barrier Didoes in 130nm CMOS Process

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Journal of Beijing Institute of Technology 2017年第2期26卷 223-227页

作者： Junyu Shi Dasheng Cui Haidong Hao Haixia Wu xin lyu School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

A polysilicon separated CMOS Schottky barrier diode is designed and tested in this *** replacing the shallow trench isolation（STI）of a ploy ring,the series resistances of Schottky diodes are reduced,leading to an improvement in cut-off *** device structure is detailed and a device model is *** analysis on the device shows that the cut-off frequency increases with the decreasing of the Schottky contact *** on this observation,the Schottky contact area is set to0.38×0.38μm^2,which is the minimum contact diffusion area allowed by the process *** distance between the anode and the cathode is also *** with different dimensions are fabricated and *** extensive measurements,the optimum dimensions are *** with a reduced area are used to improve the measurement *** measurement results show that these diodes can achieve a cut-off frequency of 1.5 ***,it is possible to use these diodes in THz detection.

关键词： Schottky barrier diodes cut-off frequency silicon THz detection