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Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 MeV neutrons with oxygen,phosphorus,and sulfur

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Chinese Physics C 2024年第3期48卷 79-92页

作者： D.n.Grozdanov n.A.Fedorov S.B.Dabylova yu.n.Kopatch I.n.Ruskov V.R.Skoy T.yu.Tretyakova C.Hramco P.I.Kharlamov G.V.Pampushik P.G.Filonchik A.V.Andreev Joint Institute for nuclear Research(JInR) DubnaRussia Institute for nuclear Research and nuclear Energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of Physics Lomonosov Moscow State UniversityMoscowRussia L.n.Gumilyov Eurasian national University AstanaKazakhstan Skobeltsyn Institute of nuclear Physics Moscow State UniversityMoscowRussia Institute of Chemistry of Moldova ChisinauRepublic of Moldova Moscow Institute of Physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 MeV on the nuclei of oxygen,phosphorus,and sulfur was performed at the TAnGRA facility at JInR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPGe)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)Ge_(3)O_(12)(BGO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(31)P,and nine transitions for the reaction with ^(32)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 MeV on ^(31)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering

Assessment of large-scale multiple forest disturbance susceptibilities with AutoML framework: an Izmir Regional Forest Directorate case

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Journal of Forestry Research 2024年第4期35卷 73-88页

作者： Remzi Eker Kamber Can Alkiş Abdurrahim Aydın Department of Forest Engineering Faculty of ForestryIzmir KatipÇelebi University35620 IzmirTurkey Graduate School of natural and Applied Sciences Izmir KatipÇelebi University35620 IzmirTurkey Department of Forest Engineering Faculty of ForestryDüzce University81620 DüzceTurkey

Disturbances such as forest fires,intense winds,and insect damage exert strong impacts on forest ecosystems by shaping their structure and growth dynamics,with contributions from climate ***,there is a need for reliable and operational methods to monitor and map these disturbances for the development of suitable management *** susceptibility assessment using machine learning methods has increased,most studies have focused on a single ***,there has been limited exploration of the use of“Automated Machine Learning(AutoML)”in the *** this study,susceptibility assessment for multiple forest disturbances(fires,insect damage,and wind damage)was conducted using the PyCaret AutoML framework in the Izmir Regional Forest Directorate(RFD)in *** AutoML framework compared 14 machine learning algorithms and ranked the best models based on AUC(area under the curve)*** extra tree classifier(ET)algorithm was selected for modeling the susceptibility of each disturbance due to its good performance(AUC values>0.98).The study evaluated susceptibilities for both individual and multiple disturbances,creating a total of four susceptibility maps using fifteen driving factors in the *** to the results,82.5%of forested areas in the Izmir RFD are susceptible to multiple disturbances at high and very high ***,a potential forest disturbances map was created,revealing that 15.6%of forested areas in the Izmir RFD may experience no damage from the disturbances considered,while 54.2%could face damage from all three *** SHAP(Shapley Additive exPlanations)methodology was applied to evaluate the importance of features on prediction and the nonlinear relationship between explanatory features and susceptibility to disturbance.

关键词： AutoML Forest disturbances Forest fire Insect Susceptibility Wind

Strong gravitational lensing of blazar gamma-radiation and intergalactic magnetic fields

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Chinese Physics C 2024年第1期48卷 184-191页

作者： yu.n.Eroshenko Institute for nuclear Research of the Russian Academy of Sciences 60th October Anniversary Prospect 7a 117312 MoscowRussi

The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is ***,two cases of strong gravitational lensing of blazar gamma-radiation are known,where radiation is deflected by galaxies on the line of sight between the blazars and *** magnetic field can affect the movements of electron-positron pairs generated by primary radiation,thereby changing the directions of secondary gamma *** modifies the equation of the gravitational lens and leads to the dependence of the observed signal in the secondary gamma radiation on the energy of photons and magnetic ***,it is possible,in principle,to estimate the intergalactic magnetic fields from the time delay of signals,from the angular position of images(for future high-resolution gamma-ray telescopes)or from the shape of the observed energy *** method is demonstrated by the example of the blazar B0218+*** this case,however,it is not possible to obtain useful constraints due to the large distances to the blazar and lens *** result is only a lower limit on the magnetic field B>2×10^(−17)G,which is weaker than other existing ***,future discoveries of lensed blazars may provide more favorable opportunities for measuring the magnetic fields,especially with the help of a new generation of gamma-ray telescopes such as e-ASTROGAM,GECAM,and SVOM as well as future gamma-ray telescopes with a high angular resolution,∼0.1″.

关键词： gravitational lensing blazar gamma-astronomy intergalactic magnetic fields

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-yu ZHOU Qiu-Yang ZHEnG yu LI Cong DInG Guang-Jian PEnG Zhong-yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 n loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Developing knn forest data imputation for Catalonia

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Journal of Forestry Research 2024年第4期35卷 142-155页

作者： Timo Pukkala núria Aquilué Ariadna Just Jordi Corbera Antoni Trasobares Forest Science and Technology Centre of Catalonia(CTFC) Crta.de St.Llorençde MorunysKm 225280 SolsonaSpain Cartographic and Geological Institute of Catalonia(ICGC) 08038 BarcelonaSpain

The combined use of LiDAR(Light Detection And Ranging)scanning and field inventories can provide spatially continuous wall-to-wall information on forest *** information can be used in many ways in forest mapping,scenario analyses,and forest manage-ment *** study aimed to find the optimal way to obtain continuous forest data for Catalonia when using knn imputation(knn stands for“k nearest neighbors”).In this method,data are imputed to a certain location from k field-measured sample plots,which are the most similar to the location in terms of LiDAR metrics and topographic *** multidimensional Euclidean distance was used as the similarity *** study tested two different methods to optimize the distance *** first method optimized,in the first step,the set of LiDAR and topographic variables used in the measure,as well as the transformations of these *** weights of the selected variables were optimized in the second *** other method optimized the variable set as well as their transformations and weights in one single *** two-step method that first finds the variables and their transfor-mations and subsequently optimizes their weights resulted in the best imputation *** the study area,the use of three to five nearest neighbors was *** and latitude turned out to be the most important variables when assessing the similarity of two locations of Catalan forests in the context of knn data *** optimal distance measure always included both LiDAR metrics and topographic *** study showed that the optimal similarity measure may be different for different ***,it was suggested that knn data imputation should always be started with the optimization of the measure that is used to select the k nearest neighbors.

关键词： Forest inventory Differential evolution Simulated annealing LiDAR

Recovering noble metals from waste streams using porous organic frameworks for heterogeneous catalysis

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Science China Chemistry 2024年

作者： yu Pan Michelle ?hlén Maria Str?mme Chao Xu Division of nanotechnology and Functional Materials Department of Materials Science and Engineering ?ngstr?m LaboratoryUppsala University State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Recovering noble metals from waste resources and incorporating them into catalysts stands out as a promising strategy for advancing sustainability within the catalysis field. This review provides a comprehensive overview of recent investigations into noble metal recovery from waste streams, specifically employing porous organic frameworks(POFs). Additionally, the study delves into the utilization of the resultant composites, enriched with noble metals, in heterogeneous catalysis. Moreover, we offer insights into the challenges faced and outline prospects for the practical implementation of extracting noble metal catalysts from waste streams using POFs, aiming to develop cost-effective, sustainable, and efficient heterogeneous catalysts.

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Studies on the temporal,structural,and interacting features of the clubroot resistance gene Rcr1 using CRISPR/Cas9-based systems

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Horticultural Plant Journal 2024年第4期10卷 1035-1048页

作者： Hao Hu Fengqun yu Agriculture and Agri-Food Canada Saskatoon Research and Development Centre107 Science PlaceSaskatoonSKS7N OX2Canada

Clubroot disease is a severe threat to Brassica crops globally,particularly in western *** resistance,achieved through pyramiding clubroot resistance(CR)genes with different modes of action,is the most important strategy for managing the ***,studies on the CR gene functions are quite *** this study,we have conducted investigations into the temporal,structural,and interacting features of a newly cloned CR gene,Rcr1,using CRISPR/Cas9 *** temporal functionality,we developed a novel CRISPR/Cas9-based binary vector,pHHIGR-Hsp18.2,to deliver Rcr1 into a susceptible canola line(DH12075)and observed that early expression of Rcr1 is critical for conferring *** structural functionality,several independent mutations in specific domains of Rcr1 resulted in loss-offunction,highlighting their importance for CR *** the study of the interacting features of Rcr1,a cysteine protease gene and its homologous allele in canola were successfully disrupted via CRISPR/Cas9 as an interacting component with Rcr1 protein,resulting in the conversion from clubroot resistant to susceptible in plants carrying intact *** results indicated an indispensable role of these two cysteine proteases in Rcr1-mediated resistance *** study,the first of its kind,provides valuable insights into the functionality of ***,the new vector p HHIGR-Hsp18.2 demonstrated an inducible feature on the removal of add-on traits,which should be useful for functional genomics and other similar research in brassica crops.

关键词： Clubroot resistance Brassica crops Canola Rcr1 CRISPR/Cas9 system Gene knock-out Timing control non-synonymous mutation Protein-protein interaction

Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests

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Journal of Forestry Research 2024年第2期35卷 70-80页

作者： Aleksey S.Ilintsev Elena n.nakvasina Alexander P.Bogdanov northern Research Institute of Forestry 13 Nikitova Str.Arkhangelsk 163062Russian Federation Department of Silviculture and Forest Management Northern(Arctic)Federal University Named After M.V.LomonosovSevernoy Dviny Emb.17Arkhangelsk 163002Russian Federation

This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of *** study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess *** the rooting layer,240 soil samples were taken to determine physical *** study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina ***,reduced soil moisture was noted,particularly in mounds,resulting in increased *** Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the *** treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration *** the Myrtillus and Polytrichum sites,patch scarification had no effects on physical *** Polytrichum sites,survival rates,heights,and heigh increments of bareroot norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to *** Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil *** conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.

关键词： Boreal forests Mechanical site preparation Patch scarification Mounding Soil properties Containerised seedlings Bareroot seedlings

new model of linkage evolution for the transtensional fault systems in the nanpu Sag of Bohai Bay Basin: Insight from seismic interpretation and analogue modelling

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Petroleum Science 2024年第4期21卷 2287-2310页

作者： yu-Heng Wang Fu-Sheng yu Bao-Yin Zhao Ling-Jian Meng College of Geosciences China University of Petroleum (Beijing) State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Jidong oilfield Company PetroChina Limited Company

The evolution of faults within the same stress field is frequently influenced by numerous factors,involving the reactivation of pre-existing structures, stress transmission through ductile detachment layers, and the growth, interaction, as well as linkage of new fault segments. This study analyses a complex multi-phase oblique extension fault system in the nanpu Sag(nPS) of the Bohai Bay Basin(BBB),China. High-resolution three-dimensional(3D) seismic data and analogue modelling indicate that the oblique extensional reactivation of pre-existing structures governs the sequential arrangement of fault segments in the caprock, and they dip synthetically to the reactivated fault at depth. During the nW-SE extension in the Eocene, the predominant movement of the pre-existing fault is strike-slip. Subsequently,during the n-S extension since the Oligocene, inclined at *** the pre-existing fault, forming splay fault segments and ultimately creating large en-echelon arcuate faults linked by relay ramps. Using fault throw-distance(T-D) and laser scanning, we reconstructed the fault evolution model of oblique extension reactivation in the presence of a ductile detachment basement. Our study illustrates that the arcuate faults can be categorized into linear master fault segments controlled by pre-existing structures, bending splay faults in the termination zone, and normal fault segments responding to the regional stress *** interaction between faults occurs among normal faults and strike-slip faults, and the kinematic unification of the two fault systems is accomplished in the intersection zone. As the faults continue to evolve, the new fault segments tend to relinquish the control of pre-existing structures and concentrate more on the development of planar and continuous major faults. The ductile detachment layer significantly contributes to the uniform distribution of strain, resulting in narrow shear zones and discontinuous normal faults in its absence.

关键词： Analogue modelling Transtensional deformation Fault linkage Fault intersection zone nanpu Sag of Bohai Bay basin