Study on Quantitative Precipitation Estimation by Polarimetric Radar Using Deep Learning

Accurate radar quantitative precipitation estimation(QPE)plays an essential role in disaster prevention and mitigation.In this paper,two deep learning-based QPE networks including a single-parameter network and a multi-parameter network are designed.Meanwhile,a self-defined loss function(SLF)is proposed during modeling.The dataset includes Shijiazhuang S-band dual polarimetric radar(CINRAD/SAD)data and rain gauge data within the radar’s 100-km detection range during the flood season of 2021 in North China.Considering that the specific propagation phase shift(KDP)has a roughly linear relationship with the precipitation intensity,KDP is set to 0.5°km^(-1 )as a threshold value to divide all the rain data(AR)into a heavy rain(HR)and light rain(LR)dataset.Subsequently,12 deep learning-based QPE models are trained according to the input radar parameters,the precipitation datasets,and whether an SLF was adopted,respectively.The results suggest that the effects of QPE after distinguishing rainfall intensity are better than those without distinguishing,and the effects of using SLF are better than those that used MSE as a loss function.A Z-R relationship and a ZH-KDP-R synthesis method are compared with deep learning-based QPE.The mean relative errors(MRE)of AR models using SLF are improved by 61.90%,51.21%,and 56.34%compared with the Z-R relational method,and by 38.63%,42.55%,and 47.49%compared with the synthesis method.Finally,the models are further evaluated in three precipitation processes,which manifest that the deep learning-based models have significant advantages over the traditional empirical formula methods.

Genomic analysis provides insights into the westward expansion of domesticated peaches in China

Peach, an economically important model plant of the Rosaceae family, has been domesticated and cultivated in China for approximately5 000 years. The Hexi Corridor, an important corridor connecting east-central China and the Tarim Basin, is the starting point of the Silk Road that links China and the Eurasian region. As a globally distributed fruit tree, the spread of peach was accomplished through historical trade routes in the Hexi Corridor and the Tarim Basin. However, knowledge of peach genetic diversity in these regions remains limited. In this study,we examined the relationships and the spread history of domesticated peaches through sequencing and genomic analysis of 161 peach accessions collected from Northwest China, including 43 from the Hexi Corridor and 104 from the Tarim Basin. The results indicate that peach landraces in the Hexi Corridor and the Tarim Basin are derivatives of peaches from the east and south of China (ESC). Notably, the genetic diversity of accessions from both the Hexi Corridor and the Tarim Basin was lower than that of ESC accessions. Reduction of diversity (ROD) and linkage disequilibrium (LD) analyses detected a genetic bottleneck in peaches from these regions. Additionally, these peaches have undergone varying degrees of selection from natural environment. Moreover, genes responsive to biotic and abiotic stresses were under selection, which could be the result of the climate change of Northwest China after the Last Glacial Maximum (LGM). Our findings provide a better understanding of the genetic basis of peach migration in Northwest China. Furthermore, this study expands the available genomic data for peaches and provides critical information for future peach breeding programs.

Peculiarity of transcriptional and H3K27me3 dynamics during peach bud dormancy

Bud dormancy facilitates the survival of meristems under harsh environmental conditions.To elucidate how molecular responses to chilling accumulation controlling dormancy in peach buds,chromatin immunoprecipitation sequencing to identify the H3K27me3 modifications and RNA sequencing of two peach cultivars with pronounced differences in chilling requirement were carried out,the results showed that genes associated with abscisic acid and gibberellic acid signal pathways play key roles in dormancy regulation.The results demonstrated that peach flower bud differentiation occurred continuously in both cultivars during chilling accumulation,which was correlated with the transcript abundance of key genes involved in phytohormone metabolism and flower bud development under adverse conditions.The more increased strength in high chillingrequirement cultivar along with the chilling accumulation at the genome-wide level.The function of the dormancy-associated MADS-box gene PpDAM6 was identified,which is involved in leaf bud break in peach and flower development in transgenic Nicotiana tabacum(NC89).In addition,PpDAM6 was positively regulated by PpCBF,and the genes of putative dormancy-related and associated with metabolic pathways were proposed.Taken together,these results constituted a theoretical basis for elucidating the regulation of peach bud dormancy transition.

Genetic Resources,Breeding Programs in China,and Gene Mining of Peach:A Review

Research on peach genetic resources and breeding has achieved remarkable progress in recent decades,especially in China.In this review,we first described the geographic distribution,ecology,phenotypes,and genetic diversity of peach landraces and wild relatives in China.We also discussed the almond.Subsequently,breeding programs of peaches in China are summarized,including breeding history,breeding targets,breeding institutes,elite breeding materials,breeding solutions,and domestically bred representative cultivars.Furthermore,we reviewed the genes or loci that have been mined using both linkage mapping and genome wide association study(GWAS)as well as the evolutionary genetics and domestication history of the peach.Finally,we gave our perspectives and suggestions for future breeding in terms of breeding material selection and breeding technology innovation.

Effects of complement inhibition on the ABC phenomenon in rats

Researchers reported that intravenously injected PEGylated colloidal drug carriers lose their long-circulating characteristic and accumulated extensively in liver when they are administrated twice in the same animal with certain intervals. This phenomenon was referred to as the 'accelerated blood clearance(ABC) phenomenon'. Some former studies had found that complement-mediated phagocytosis, activated by antigen–antibody complex, was responsible for inducing the phenomenon. According to the theory, we have used cobra venom factor to deplete complement in vivo and to investigate the effect of complement inhibition on the ABC phenomenon. Rats were administered by injection of cobra venom factor solution to build up the model of complement exhaustion/inhibition, and the effect of the inhibition of complement on ABC phenomenon was carried out. It seemed that inhibition of complement didn’t affect the pharmacokinetic of the first infection. By contrast, in rats of which complement had been depleted, the second dose of PEGylated nanoemulsions showed enhanced circulation time compared with normal rats in a complement inhibition-independent manner, but the ABC phenomenon was not completely eliminated. It indicated that complement inhibition could certainly weaken the accelerated clearance;meanwhile, there were other factors causing the ABC effect.These findings provide novel insights into the attenuating of ABC phenomenon and lay foundation for further study of immune mechanism.

Optimization of Ultrasonic Extraction Conditions of Polyphenols from the Needles of Black Pine (Pinus thunbergii) Using Response Surface Methodology (RSM)

Ultrasonic extraction conditions of polyphenols from the needles of black pine(Pinus thunbergii) were optimized by single factors analysis and Box-Behnken experiment design. The results showed that both of ethanol concentration and ultrasonic time had a significant effect on polyphenol extraction, and there was significant interaction between any two variables in the three parameters of ethanol concentration, ultrasonic temperature and ultrasonic time. The optimal parameters for polyphenol extraction were the ethanol concentration of 52.67%, ultrasonic temperature at 49.21 ℃and ultrasonic time of 30.76 min. Under these conditions, the actual content of polyphenols was close to the predicted value. Therefore, the process can be used to extract polyphenols from black pine needles.

The accelerated blood clearance phenomenon of PEGylated nanoemulsion upon cross administration with nanoemulsions modified with polyglycerin

For investigating the accelerated blood clearance(ABC) phenomenon of polyglycerin modified nanoemulsions upon cross administration with polyethylene glycol(PEG) covered nanoemulsion, we used the 1,2-distea-royl-sn-glycero-3-phosphoethanolamine-npolyglycerine-610 and the 1,2-distearoyl-n-glycero-3-phosphoethanolamine-n-[methoxy(polyethylene glycol)-2000] as modify materials, the dialkylcarbocyanines as fluorescence indicator. Exhausted macrophages rat model was established and new material containing polycarboxyl structure was synthesized. The microplate reader and the in vivo optical imaging system were applied to measure the concentration of nanoemulsions in tissues.The results show that the first dose of polyglycerin modified nanoemulsion can induce the ABC phenomenon of the second dose of PEGylated nanoemulsion. With the increase in the amount of the surface polyglycerin, the extent of the ABC phenomenon decreases. Liver accumulation has positive relationship with the ABC phenomenon. Furthermore, kupffer cells in liver can get more immune information from polyhydroxy structure than polycarboxyl group in the modify compound. The results of our work imply that the polycarboxyl structure has advantages to eliminate the ABC phenomenon.

High-precision three-dimensional Rydberg atom localization in a four-level atomic system

Rydberg atoms have been widely investigated due to their large size,long radiative lifetime,huge polarizability and strong dipole-dipole interactions.The position information of Rydberg atoms provides more possibilities for quantum optics research,which can be obtained under the localization method.We study the behavior of three-dimensional(3D)Rydberg atom localization in a four-level configuration with the measurement of the spatial optical absorption.The atomic localization precision depends strongly on the detuning and Rabi frequency of the involved laser fields.A 100%probability of finding the Rydberg atom at a specific 3D position is achieved with precision of~0.031λ.This work demonstrates the possibility for achieving the 3D atom localization of the Rydberg atom in the experiment.

Allelopathic Effect of Black Pine( Pinus thunbergii) Needles and Litter on Four Cover Plants

Black pine( Pinus thunbergii) is one of the main afforestation species in the sandy coast and the preferred tree species for landscape green in northern China.Allelopathic activity could be one of the reasons of the sparse vegetation under black pine forests.To explore the allelopathic potential of P.thunbergii,the effects of litter and fresh needles were evaluated against the common cover plants seeds and seedlings,i.e.Tateges erecta,Orychophragmus violaceus,Ophiopogon japonicas and Trifolium repens.The results showed that P.thunbergii possessed allelopathic potential to the accompanying plants.Increasing concentrations of aqueous extracts of needles and litter affected target plant development in different levels.Growth and germination inhibition were directly related to the extract concentrations of needles or litters.Fresh needles played a more important role in the inhibition to target plants than litter because of the less germination rate and biomass in the same concentration.In addition,the adaptability of cover plants to the allelopathic effects of P.thunbergii is obviously different.The sensitivities of the four cover plants to the allelopathic effects of P.thunbergii were in order of T.repens > O.japonicas > O.violaceus > T.erecta.Therefore,T.repens is least suitable for concomitant planting with P.thunbergii,and T.erecta is the most suitable,with other two plants in between in landscape configuration.

High Proportion Renewable Energy Supply and Demand Structure Model and Grid Impaction

In considering of high proportion of renewable energy supply in 2050, the accelerating of energy consumption gross, source and environment can affect the energy system restrict affection are stronger. Add wind and solar to electricity energy with large amount of energy source exploitation. The energy source amount per person is lower. Considering the renewable energy amount and supply, primary energy storage and structure problem is standing out. Before the wide spread of renewable energy, Using the high-carbon energy in China can pollute seriously. Chinese energy supply and demand problem is research key point. This paper researches Chinese energy supply and demand pattern system and evaluation methodology, gives out the inner and outer influencing elements. And evaluate Chinese energy supply and demand pattern from energy gross, structure, distribution and transportation. Use energy supply synthesize radar comparison chart in certain time period. From energy security, economy, clean and efficiency, analyze the benefit comparisons of Chinese energy supply and demand pattern. This energy supply and demand pattern model will give one certain theoretical analysis and practice reference to the further high proportion of renewable energy.

二维磁性拓扑材料:基础理论、材料实现及应用前景

在二维材料的研究中,二维磁性和非平庸拓扑能带成为研究焦点.最近,涌现出一类新型材料体系,被称为二维磁性拓扑材料.它们巧妙地将二维磁性与非平庸拓扑特性相结合,引起人们的广泛研究兴趣.特别是在二维尺度上已推出几种新型磁性拓扑态,如反铁磁拓扑绝缘体/半金属、磁性二阶拓扑绝缘体等.本综述全面分析了目前二维磁性拓扑材料领域的研究进展,包括各类二维磁性拓扑绝缘体、二维磁性拓扑半金属以及完全自旋极化二维拓扑半金属等;系统性地剖析了基础拓扑理论、发展历程、材料实现以及潜在应用.最后,讨论了该领域所面临的挑战与前景,强调了未来在这一引人注目的领域取得更大突破的可能途径.

Jigsaw-like mini-pillar platform for multi-mode biosensing

The multiple sensing provides booming options to eliminate interference and ensure the accuracy of detection by mutually coupling and validating multiple data sets.Here,we integrate the jigsaw-like multifunctional mini-pillar platform to perform multi-mode(electrochemical,fluorescence,surface-enhanced Raman scattering(SERS)and colorimetric)sensing in individual microdroplets.Each mini-pillar connector can parallelize together by specific concave-convex interface to form integrated jigsaw-like platform for multi-mode sensing,and each specific mini-pillar can be modified into the individual sensing unit to read the prescribed signals.We successfully implemented electrochemical,fluorescence,SERS and colorimetric detection by multiple signals coupling to reduce the false positive analysis.Such platform brings a promising clue of in-situ analysis and point-of-care testing for disease diagnosis and health monitoring.

Enhanced nonlinearity for filamentation in gold-nanoparticle-doped water

We report a universal approach based on the surface plasmon resonances(SPRs) attained in filamentation in water doped with gold nanoparticles for enhancing the nonlinear refractive index. The filament-induced supercontinuum spectrum in water overlaps with SPRs of gold nanospheres, which further leads to a modification on the Kerr nonlinear refractive index. In our experiment, the measured nonlinear refractive index(n_2) in water doped with gold nanoparticles increases by six times, as compared with that in pure water. Such enhancement may be useful for filament-induced nonlinear applications with modest incident intensity.

Photonic graphene with reconfigurable geometric structures in coherent atomic ensembles

Photonic graphene,possesses a honeycomb-like geometric structure,provides a superior platform for simulating photonic bandgap,Dirac physics,and topological photonics.Here,the photonic graphene with reconfigurable geometric structures is demonstrated in a 5S_(1/2)–5P_(3/2)–5D_(5/2) cascade-type 85Rb atomic ensembles.A strong hexagonal-coupling field,formed by the interference of three identical coupling beams,is responsible for optically inducing photonic graphene in atomic vapor.The incident weak probe beam experiences discrete diffraction,and the observed pattern at the output plane of vapor cell exhibits a clear hexagonal intensity distribution.The complete photonic graphene geometries from transversely stretched to longitudinally stretched are conveniently constructed by varying the spatial arrangement of three coupling beams,and the corresponding diffraction patterns are implemented theoretically and experimentally to map these distorted geometric structures.Moreover,the distribution of lattice sites intensity in photonic graphene is further dynamically adjusted by two-photon detuning and the coupling beams power.This work paves the way for further investigation of light transport and graphene dynamics.

The commercial antibiotics with inherent AIE feature: In situ visualization of antibiotic metabolism and specifically differentiation of bacterial species and broad-spectrum therapy

The research on pharmacology usually focuses on the structure-activity relationships of drugs,such as antibiotics,to enhance their activity,but often ignores their optical properties.However,investigating the photophysical properties of drugs is of great significance because they could be used to in situ visualize their positions and help us to understand their working metabolism.In this work,we identified a class of commercialized antibiotics,such as levofloxacin,norfloxacin,and moxifloxacin(MXF)hydrochloride,featuring the unique aggregation-induced emission(AIE)characteristics.By taking advantage of their AIE feature,antibiotic metabolism in cells could be in situ visualized,which clearly shows that the luminescent aggregates accumulate in the lysosomes.Moreover,after a structure-activity relationship study,we found an ideal site of MXF to be modified with a triphenylphosphonium and an antibiotic derivative MXF-P was prepared,which is able to specifically differentiate bacterial species after only 10 min of treatment.Moreover,MXF-P shows highly effective broad-spectrum antibacterial activity,excellent therapeutic effects and biosafety for S.aureus-infected wound recovery.Thus,this work not only discovers the multifunctionalities of the antibiotics but also provides a feasible strategy to make the commercialized drugs more powerful.

A novel histone deacetylase inhibitor exerts promising anti-breast cancer activity via triggering AIFM1-dependent programmed necrosis

Dear Editor,Breast cancer is one of the most lethal cancers in women,with many patients still succumbing to this dis-ease[1].Accumulating evidence demonstrates that histone deacetylase inhibitors(HDACIs)are a promising therapeu-tic intervention for breast cancer[2],and many of them have shown favorable anti-cancer activities in both pre-clinical and clinical settings[3].However,most current HDACIs only exhibit limited efficacy against solid tumors with toxic side effects and readily produce drug resistance[4].Therefore,it is necessary to develop new HDACIs with improved anti-tumor activities and decreased toxic-ities for breast cancer therapeutics and investigate their mechanism of action.

Determination of hyperfine structure constants of 5D_(5/2) and 7S_(1/2) states of rubidium in cascade atomic system

We present a method to precisely determine the hyperfine structure constants of the rubidium 5D（5/2） and 7S（1/2） states in a cascade atomic system. The probe laser is coupled to the 5S（1/2）→ 5P（3/2） hyperfine transition, while the coupling laser is scanned over the 5P（3/2）→ 5D（5/2）（7S（1/2）） transition. The high-resolution double-resonance optical pumping spectra are obtained with two counter-propagating laser beams acting on rubidium vapor. The hyperfine splitting structures are accurately measured by an optical frequency ruler based on the acousto-optic modulator, thus, the magnetic dipole hyperfine coupling constant A and quadrupole coupling constant B are determined. It is of great significance for the atomic hyperfine structure and fundamental physics research.