Event vertex and time reconstruction in large-volume liquid scintillator detectors

Large-volume liquid scintillator detectors with ultra-low background levels have been widely used to study neutrino physics and search for dark matter.Event vertex and event time are not only useful for event selection but also essential for the reconstruction of event energy.In this study,four event vertex and event time reconstruction algorithms using charge and time information collected by photomultiplier tubes were analyzed comprehensively.The effects of photomultiplier tube properties were also investigated.The results indicate that the transit time spread is the main effect degrading the vertex reconstruction,while the effect of dark noise is limited.In addition,when the event is close to the detector boundary,the charge information provides better performance for vertex reconstruction than the time information.

Improvement of machine learning-based vertex reconstruction for large liquid scintillator detectors with multiple types of PMTs

The precise vertex reconstruction for large liquid scintillator detectors is essential.A novel machine learning-based method was successfully developed to reconstruct an event vertex in JUNO.In this study,the performance of machine learning-based vertex reconstruction was further improved by optimizing the input images of neural networks.By separating the information of different types of PMTs and adding the information of the second hit of PMTs,the vertex resolution was improved by approximately 9.4% at 1 MeV and 9.8% at 11 MeV.

Amethod for sharing dynamic geometry information in studies on liquid-based detectors

Liquid-based detectors are widely used in particle and nuclear physics experiments.Because fixed method is used to construct the geometry in detector simulations such as Geant4,it is usually difficult to describe the non-uniformity of the liquid in a detector.We propose a method based on geometry description markup language and a tessellated detector description to share the detector geometry information between computational fluid dynamics simulation software and detector simulation software.This method makes it possible to study the impact of a liquid flow and non-uniformity on the key performance of a liquid-based detector,such as the event vertex reconstruction resolution.This will also be helpful in the detector design and performance optimization.

Interfacial defect engineering and photocatalysis properties of hBN/MX_(2)(M=Mo,W,and X=S,Se)heterostructures

Van der Waals(VDW)heterostructures have attracted significant research interest due to their tunable interfacial properties and potential applications in many areas such as electronics,optoelectronic,and heterocatalysis.In this work,the influences of interfacial defects on the electronic structures and photocatalytic properties of hBN/MX_(2)(M=Mo,W,and X=S,Se)are studied using density functional theory calculations.The results reveal that the band alignment of hBN/MX_(2) can be adjusted by introducing vacancies and atomic doping.The type-Ⅰband alignment of the host structure is maintained in the heterostructure with n-type doping in the hBN sublayer.Interestingly,the band alignment changed into the type-Ⅱheterostructrue due to V_(B) defect and p-type doping is introduced into the hBN sublayer.This can conduce to the separation of photo-generated electron-hole pairs at the interfaces,which is highly desired for heterostructure photocatalysis.In addition,two Z-type heterostructures including h BN(BeB)/MoS_(2),hBN(Be_(B))/MoSe_(2),and hBN(V_(N))/MoSe_(2)are achieved,showing the decreasing of band gap and ideal redox potential for water splitting.Our results reveal the possibility of engineering the interfacial and photocatalysis properties of hBN/MX_(2) heterostructures via interfacial defects.

High-order harmonic generations in tilted Weyl semimetals

We investigate high-order harmonic generations(HHGs)under comparison of Weyl cones in two types.Due to the hyperboloidal electron pocket structure,strong noncentrosymmetrical generations in high orders are observed around a single type-ⅡWeyl point,especially at zero frequency.Such a remarkable DC signal is proved to have attributions from the intraband transition after spectral decomposition.Under weak pulse electric field,the linear optical response of a nontilted Weyl cone is consistent with the Kubo theory.With extensive numerical simulations,we conclude that the non-zero chemical potential can enhance the even-order generations,from the slightly tilted system to the over-tilted systems.In consideration of dynamical symmetries,type-Ⅰand type-ⅡWeyl cones also show different selective responses under the circularly polarized light.Finally,using a more realistic model containing two pairs of Weyl points,we demonstrate that paired Weyl points with opposite chirality can suppress the overall even-order generations.

Solid-Cystic Hidradenoma

Histopathology Solid-cystic hidradenoma (SCH) is located in the dermis and can be attached to the epidermis or extend into the subcutaneous tissue.The lesion is well circumscribed with clear edge.It can be encapsulated or unencapsulated.There were both a large cavity and a solid component in the tumor.The cyst is lined by flattened or cubic secretory cells,while the cystic wall is more often constituted by tumor cells.Therefore,the cystic cavity may be caused by the necrosis of tumor cell.The cysts consist of uniformly eosinophilic materials.The tumor cells were characteristic of slightly basophilic cytoplasm and round nuclei.Most SCH have a duct-like structure,which consists of a monolayer of cubical cells with eosinophilic walls (Fig.1A-1C).Tumor lobules are surrounded by collagen fibers,blood vessels,and other interstitium,which sometimes have transparent degeneration.

Chronic erythematous condition of legs

Histopathology A histopathological examination of skin lesions in mild cases of erythrocyanosis only show lymphocytic infiltration in the upper dermis. In severe cases, dilation of shallow capillaries, endothelial swelling, extravasation of erythrocytes, and occasionally throm-bosis in capillaries can also be found. In this case we described here, the epidermis did not show any abnormal features. The dermis showed dilatation of capillaries and perivascular lymphocytic infiltration (Figure 1).