αDecay in extreme laser fields within a deformed Gamow-like model

In this study, the effect of extreme laser fields on the α decay process of ground-state even–even nuclei was investigated.Using the deformed Gamow-like model, we found that state-of-the-art lasers can cause a slight change in the α decay penetration probability of most nuclei. In addition, we studied the correlation between the rate of change of the α decay penetration probability and angle between the directions of the laser electric field and α particle emission for different nuclei. Based on this correlation, the average effect of extreme laser fields on the half-life of many nuclei with arbitrary α particle emission angles was calculated. The calculations show that the laser suppression and promotion effects on the α decay penetration probability of the nuclei population with completely random α particle-emission directions are not completely canceled.The remainder led to a change in the average penetration probability of the nuclei. Furthermore, the possibility of achieving a higher average rate of change by altering the spatial shape of the laser is explored. We conclude that circularly polarized lasers may be helpful in future experiments to achieve a more significant average rate of change of the α decay half-life of the nuclei population.

Systematic study on the proton radioactivity of spherical proton emitters

In this study, based on a two-potential approach, we systematically investigated the proton radioactivity half-lives of spherical proton emitters with 69≤Z≤81 from the ground and/or isomeric state, choosing the nuclear potential to be a modified Woods–Saxon potential that contains the isospin effect of the daughter nucleus. It was found that the calculated half-lives could reproduce the experimental data well. Furthermore, we extended this model to predict the half-lives of 17 protonemitting candidates whose radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. For comparison, the unified fission model, Coulomb potential and proximity potential model, universal decay law for proton emission, and new Geiger–Nuttall law were also used. All the predicted results are consistent with each other.

Two-proton radioactivity from excited states of proton-rich nuclei within Coulomb and Proximity Potential Model

In the present work,we extend the Coulomb and Proximity Potential Model(CPPM)to study two-proton(2p)radioactivity from excited states while the proximity potential is chosen as AW95 proposed by Aage Withner in 1995.Demonstration reveals that the theoretical results acquired by CPPM exhibit a high level of consistency with prior theoretical models such as the unified fission model(UFM),generalized liquid-drop model(GLDM)and effective liquid-drop model(ELDM).Furthermore,within the CPPM,we predicted the half-lives of potential 2p radioactive nuclei for which experimental data are currently unavailable.The predicted results were then assessed,compared with UFM,ELDM and GLDM models,and examined in detail.

Unfolding analysis of LaBr3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration

With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.

Two-proton radioactivity of the excited state within the Gamow-like and modified Gamow-like models

In this study,we systematically investigated the two-proton(2p)radioactivity half-lives from the excited state of nuclei near the proton drip line within the Gamowlike model(GLM)and modified Gamow-like model(MGLM).The calculated results were highly consistent with the theoretical values obtained using the unified fission model[Chin.Phys.C 45,124105(2021)],effective liquid drop model,and generalized liquid drop model[Acta Phys.Sin 71,062301(2022)].Furthermore,utilizing the GLM and MGLM,we predicted the 2p radioactivity halflives from the excited state for some nuclei that are not yet available experimentally.Simultaneously,by analyzing the calculated results from these theoretical models,it was found that the half-lives are strongly dependent on Qand l.

Effect of Zr Content on Formation and Optical Properties of the Layered PbZrxTi1-xO3 Films

PbZrxTi1-xO3(PZT)fims are fabricated on F-doped tin oxide(FTO)substrates using chemical solutions containing PVP polymer and rapid thermal annealing processing.The dependence of the layered PZT multilayer formation and their optical properties on the Zr content x are examined.It is found that all the PZT films are crystallized and exhibit 110-preferred orientation.When x varies in the region of 0-0.8,the PZT films display lamellar structures,and a high reflection band occurs in each optical reflectance spectrum curve.Especially,those PZT fikms with Zr/Ti atomic ratio of 35/65-65/35 show clearly layered cross-sectional morphologies arranged alternatively by porous and dense PZT layers,and have a peak optical reflectivity of>70%and a band width of>45 nm.To obtain the optimal Bragg reflection performance of the PZT multilayers,the Zr content should be selected in the range of 0.35-0.65.

Systematic calculations of cluster radioactivity half-lives with a screened electrostatic barrier

In this study,based on Wentzel-Kramers-Brillouin theory,we systematically investigate the cluster radioactivity half-lives of 22 nuclei ranging from^(221)Fr to^(242)Cm using a phenomenological model that considers the screened electrostatic effect of the Coulomb potential.In this model,there are two adjustable parameters,t and g,which are related to the screened electrostatic barrier and the strength of the spectroscopic factor,respectively.The calculated results indicate that this model can effectively reproduce the experimental data,with a corresponding rootmean-square deviation of 0.660.In addition,we extend this model to predict the half-lives of possible cluster radioactive candidates whose cluster radioactivities are energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2020.The predicted results are consistent with those obtained using other theoretical models and/or empirical formulas,including the universal decay law proposed by Qi et al.[Phys.Rev.C 80,044326(2009)],a semi-empirical model for bothαdecay and cluster radioactivity proposed by Santhosh et al.[J.Phys.G 35,085102(2008)],and a unified formula for the half-lives ofαdecay and cluster radioactivity proposed by Ni et al.[Phys.Rev.C 78,044310(2008)].

ATP50 Hypo-crotonylation Caused by HDAC2 Hyper-Phosphorylation Is a Primary Detrimental Factor for Downregulated Phospholipid Metabolism under Chronic Stress

Objective.Chronic stress(CS)-induced abnormal metabolism and other subsequent aspects of abnormality are threatening human health.Little is known regarding whether and how protein post-translational-modifications(PTMs)correlate with abnormal metabolism under CS.The aim of this study was to address this issue and also identify novel key protein PTM.Methods.First,we screened which pan-PTM had significant change between control and CS female mice and whether clinical CS females had similar pan-PTM change.Second,we performed quantitative PTM-omics and metabolomics to verify the correlation between abnormal protein PTMs and atypical metabolism.Third,we performed quantitative phospho-omics to identify the key PTM-regulating enzyme and investigate the interaction between PTM protein and PTM-regulating enzyme.Fourth,we attempted to rectify the abnormal metabolism by correcting the activity of the PTM-regulating enzyme.Finally,we examined whether the selected key protein was also correlated with stress scores and atypical metabolism in clinical women.Results.We initially found that multiple tissues of CS female mice have downregulated pan-crotonylation,and verified that the plasma of clinical CS females also had downregulated pan-crotonylation.Then we determined that ATP5O-K51 crotonylation decreased the most and also caused gross ATP5O decrement,whereas the plasma of CS mice had downregulated phospholipids.Next,downregulating ATP5O crotonylation partially recapitulated the downregulated phospholipid metabolism in CS mice.Next,we verified that HDAC2-S424 phosphorylation determined its decrotonylation activity on ATP5O-K51.Furthermore,correcting HDAC2 hyper-phosphorylation recovered the gross ATP5O level and partially rescued the downregulated phospholipid metabolism in CS mice.Finally,the ATP5O level was also significantly iower and correlated with high stress scores and downregulated phospholipid metabolism in clinical female plasma.Conclusion.This study discovered a novel PTM mechanism involving two distinct types of PTM in CS and provided a novel reference for the clinical precautions and treatments of CS.

Estimating the prevalence of Echinococcus in domestic dogs in highly endemic for echinococcosis

Background:Cystic echinococcosis(CE)and alveolar echinococcosis(AE)are highly endemic in Xiji County of Ningxia Hui Autonomous Region(NHAR)in China where the control campaign based on dog de-worming with praziquantel has been undertaken over preceding decades.This study is to determine the current prevalence of Echinococcus granulosus and E.multilocularis in domestic dogs and monitor the echinococcosis transmission dynamics.Methods:Study villages were selected using landscape patterns(Geographic Information System,GIS)for Echinococcus transmission“hot spots”,combined with hospital records identifying risk areas for AE and CE.A survey of 750 domestic dogs,including copro-sampling and owner questionnaires,from 25 selected villages,was undertaken in 2012.A copro-multiplex PCR assay was used for the specific diagnosis of E.granulosus and E.multilocularis in the dogs.Data analysis,using IBM SPSS Statistics,was undertaken,to compare the prevalence of the two Echinococcus spp.in dogs between four geographical areas of Xiji by theχ^(2)test.Univariate analysis of the combinations of outcomes from the questionnaire and copro-PCR assay data was carried out to determine the significant risk factors for dog infection.Results:The highest de-worming rate of 84.0%was found in the northwest area of Xiji County,and significant differences(P<0.05)in the de-worming rates among dogs from the four geographical areas of Xiji were detected.The highest prevalence(19.7%,59/300)of E.multilocularis occurred in northwest Xiji,though the highest prevalence(18.1%,38/210)of E.granulosus occurred in southwest Xiji.There was no significant difference(P>0.05)in the prevalence of E.granulosus in dogs from the northwest,southwest,northeast,and southeast of Xiji,but there were significant differences(P<0.05)between dogs infected with E.multilocularis from the four areas.None of the other independent variables was statistically significant.Conclusions:The results from this study indicate a high prevalence of both E.granulosus and E.muiltilocularis in dogs in Xiji County,NHAR.Transmission of E.multilocularis was more impacted by geographical risk-factors in Xiji County than that of E.granulosus.Dogs have the potential to maintain the transmission of both species of Echinococcus within local Xiji communities,and the current praziquantel dosing of dogs appears to be ineffective or poorly implemented in this area.

Randomized Primal–Dual Proximal Block Coordinate Updates

In this paper,we propose a randomized primal–dual proximal block coordinate updating framework for a general multi-block convex optimization model with coupled objective function and linear constraints.Assuming mere convexity,we establish its O(1/t)convergence rate in terms of the objective value and feasibility measure.The framework includes several existing algorithms as special cases such as a primal–dual method for bilinear saddle-point problems(PD-S),the proximal Jacobian alternating direction method of multipliers(Prox-JADMM)and a randomized variant of the ADMM for multi-block convex optimization.Our analysis recovers and/or strengthens the convergence properties of several existing algorithms.For example,for PD-S our result leads to the same order of convergence rate without the previously assumed boundedness condition on the constraint sets,and for Prox-JADMM the new result provides convergence rate in terms of the objective value and the feasibility violation.It is well known that the original ADMM may fail to converge when the number of blocks exceeds two.Our result shows that if an appropriate randomization procedure is invoked to select the updating blocks,then a sublinear rate of convergence in expectation can be guaranteed for multi-block ADMM,without assuming any strong convexity.The new approach is also extended to solve problems where only a stochastic approximation of the subgradient of the objective is available,and we establish an O(1/√t)convergence rate of the extended approach for solving stochastic programming.

A Variant of Multi-task n-vehicle Exploration Problem: Maximizing Every Processor's Average Profit

We discuss a variant of the multi-task n-vehicle exploration problem. Instead of requiring an optimal permutation of vehicles in every group, the new problem requires all vehicles in a group to arrive at the same destination. Given n tasks with assigned consume-time and profit, it may also be viewed as a maximization of every processor＇s average profit. Further, we propose a new kind of partition problem in fractional form and analyze its computational complexity. By regarding fractional partition as a special case, we prove that the average profit maximization problem is NP-hard when the number of processors is fixed and it is strongly NP- hard in general. At last, a pseudo-polynomial time algorithm for the average profit maximization problem and the fractional partition problem is presented, using the idea of the pseudo-polynomial time algorithm for the classical partition problem.

Early Research on COVID-19: A Bibliometric Analysis

In December 2019,an outbreak of pneumonia,which was named COVID-2019,emerged as a global health crisis.Scientists worldwide are engaged in attempts to elucidate the transmission and pathogenic mechanisms of the causative coronavirus.COVID-19 was declared a pandemic by the World Health Organization in March 2020,making it critical to track and review the state of research on COVID-19 to provide guidance for further investigations.Here,bibliometric and knowledge mapping analyses of studies on COVID-19 were performed,including more than 1,500 papers on COVID-19 available in the PubMed and China National Knowledge Infrastructure databases from January 1,2020 to March 8,2020.In this review,we found that because of the rapid response of researchers worldwide,the number of COVID-19-related publications showed a high growth trend in the first 10 days of February;among these,the largest number of studies originated in China,the country most affected by pandemic in its early stages.Our findings revealed that the epidemic situation and data accessibility of different research teams have caused obvious difference in emphases of the publications.Besides,there was an unprecedented level of close cooperation and information sharing within the global scientific community relative to previous coronavirus research.We combed and drew the knowledge map of the SARS-CoV-2 literature,explored early status of research on etiology,pathology,epidemiology,treatment,prevention,and control,and discussed knowledge gaps that remain to be urgently addressed.Future perspectives on treatment,prevention,and control are also presented to provide fundamental references for current and future coronavirus research.

Systematic study on α-decay half-lives of uranium isotopes with a screened electrostatic barrier

In the present work,we systematically study the α-decay half-lives of uranium(Z=92) isotopes based on the Gamow model with a screened electrostatic barrier.There are only two adjustable parameters in our model i.e.the parameter g and the screening parameter t in the Hulthen potential for considering the screened electrostatic effect of the Coulomb potential.The calculated results are in good agreement with experimental data,and the corresponding root-mean-square(rms) deviations of uranium isotopes with α transition orbital angular momentum l=0 and l=2 are 0.141 and 0.340,respectively.Moreover,we extend this model to predict α-decay half-lives of uranium isotopes whose a decay is energetically allowed or observed but not yet quantified in NUBASE2020.For comparison,the modified Hatsukawa formula(XLZ),the unified Royer formula(DZR),the universal decay law(UDL) and the Viola-Seaborg-Sobiczewski formula(VSS) are also used.The predictions are basically consistent with each other.Meanwhile,the results also indicate that N=126 shell closure is still robust at Z=92 and the spectroscopic factor S_(α) is almost the same for uranium isotopes with the same l.

Two-proton radioactivity within Coulomb and proximity potential model

Considering the preformation probability of the two emitted protons in the parent nucleus,we extend the Coulomb and proximity potential model(CPPM)to systematically study two-proton(2p)radioactivity half-lives of the nuclei close to proton drip line.The proximity potential chosen is Prox.81 proposed by Blocki et al.in 1981.Furthermore,we apply this model to predict the half-lives of possible 2p radioactive candidates whose 2p radioactivity is energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2016.The predicted results are in good agreement with those from other theoretical models and empirical formulas,namely the effective liquid drop model(ELDM),generalized liquid drop model(GLDM),Gamow-like model,Sreeja formula and Liu formula.

Comparative transcriptome and co-expression analysis reveal key genes involved in leaf margin serration in Perilla frutescens

Objective:In this study,we aimed to identify the genes involved in leaf margin serration in Perilla frutescens.P.frutescens(Family:Lamiaceae)is widely grown in Asian countries.Perilla leaf is the medicinal part stipulated in the Chinese Pharmacopoeia.There are mainly two types of perilla leaves:one with serrated leaf margin which is the phenotype described in the pharmacopoeia and the other with smooth leaf margin.Methods:Transcriptome sequencing,co-expression analysis,and qRT-PCR analysis of six perilla tissues sampled from two different phenotypes(serrated and smooth leaves)were performed.Results:Forty-three differentially expressed genes(DEGs),which may potentially regulate leaf shape,were identified through de novo transcriptome sequencing between the two groups.Genes involved in leaf shape regulation were identified.Simultaneously,we validated five DEGs by qRT-PCR,and the results were consistent with the transcriptome data.In addition,1186 transcription factors(TFs)belonging to 45 TF families were identified.Moreover,the co-expression network of DEGs was constructed.Conclusion:The study identified the key genes that control leaf shape by comparing the transcriptomes.Our findings also provide basic data for further exploring P.frutescens,which can help study the mechanism of leaf shape development and molecular breeding.

异核双金属协同催化环氧环己烷与邻苯二甲酸酐无规共聚

设计、合成了一种新型异核双金属配合物,用于催化环氧环己烷(CHO)和邻苯二甲酸酐(PA)的共聚反应,以制备聚(醚-酯)材料.分别通过核磁共振波谱和电喷雾质谱对聚合物及其水解后产物结构进行分析,证明所得共聚物为醚酯单元呈无规分布的聚(醚-酯).重点考察了配体结构、金属离子、反应温度和催化剂浓度对聚合反应的影响.最后,对所得聚(醚-酯)无规共聚物热性能进行研究,表明聚醚链段的引入可以调变其玻璃化转变温度,丰富了此类聚酯材料的应用场景.