WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target tracking.First,the steps of extended Kalman filtering(EKF)are introduced.Second,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile target.Finally,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed algorithm.The comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

Circular RNA ciRS-7 promotes the proliferation and metastasis of pancreatic cancer by regulating miR-7-mediated EGFR/STAT3 signaling pathway

Background: Pancreatic ductal adenocarcinoma(PDAC) is the most deadly type of tumor, and its pathogenesis remains unknown. Circular RNAs(circRNAs) may be functional and bind to micro RNAs and consequently, influence the activity of targeted mRNAs. Recent researches indicate that one circRNA, ciRS-7, acts as a sponge of miR-7 and thus, inhibits its activity. It is well known that miR-7 is a cancer suppressor in many cancers. However, the relationship between ciRS-7 and miR-7, and the role of ciRS-7 in PDAC, remains to be elucidated. Methods: miR-7 and ciRS-7 expression in 41 pairs of PDAC tumors and their paracancerous tissues were detected by quantitative reverse transcription polymerase chain reaction(qRT-PCR). The relationships between their expression levels and clinicopathological features in PDAC tissues were assessed. The relationship between miR-7 and ciRS-7 was also assessed by Spearman’s correlation. We also used cell lines to evaluate the role of ciRS-7 in cell line behavior. The ciRS-7 interfere RNA(si RNA) and its empty vector were transfected into PDAC cells. PDAC cells proliferation and invasion abilities were detected by MTT assay and invasion analysis. The expression of proteins was assessed by Western blotting. Results: ciRS-7 expression was significantly higher in PDAC tissues than paracancerous tissues( P = 0.002). However, miR-7 expression showed the opposite trend( P = 0.048). Moreover, ciRS-7 expression was inversely correlated with miR-7 in PDAC( r s =-0.353, P = 0.023). ciRS-7 expression was also significantly elevated in venous invasion(3.72 ± 2.93 vs. 2.14 ± 1.26;P = 0.028) and lymph node metastasis(4.19 ± 2.75 vs. 2.32 ± 1.90;P = 0.016) in PDAC patients. Furthermore, ciRS-7 knockdown suppressed cell proliferation and invasion of PDAC cells( P < 0.05), and the downregulation of ciRS-7 resulted in miR-7 overexpression and subsequent inhibition of epidermal growth factor receptor(EGFR) and signal transducer and activator of transcription 3(STAT3). Conclusions: Circular RNA ciRS-7 plays an oncogene role in PDAC, partly by targeting miR-7 and regulating the EGFR/STAT3 signaling pathway.

Laparoscopic distal pancreatectomy is as safe and feasible as open procedure:A meta-analysis

AIM:To evaluate the feasibility and safety of laparoscopic distal pancreatectomy(LDP) compared with open distal pancreatectomy(ODP).METHODS:Meta-analysis was performed using the databases,including PubMed,the Cochrane Central Register of Controlled Trials,Web of Science and BIOSIS Previews.Articles should contain quantitative data of the comparison of LDP and ODP.Each article was reviewed by two authors.Indices of operative time,spleen-preserving rate,time to fluid intake,ratio of malignant tumors,postoperative hospital stay,incidence rate of pancreatic fistula and overall morbidity rate were analyzed.RESULTS:Nine articles with 1341 patients who underwent pancreatectomy met the inclusion criteria.LDP was performed in 501(37.4%) patients,while ODP was performed in 840(62.6%) patients.There were significant differences in the operative time,time to fluid intake,postoperative hospital stay and spleen-preserving rate between LDP and ODP.There was no difference between the two groups in pancreatic fistula rate [random effects model,risk ratio(RR) 0.996(0.663,1.494),P = 0.983,I2 = 28.4%] and overall morbidity rate [random effects model,RR 0.81(0.596,1.101),P = 0.178,I2 = 55.6%].CONCLUSION:LDP has the advantages of shorter hospital stay and operative time,more rapid recovery and higher spleen-preserving rate as compared with ODP.

Long-term outcomes after hepatectomy of huge hepatocellular carcinoma: A single-center experience in China

Background: Currently, hepatectomy remains the first-line therapy for hepatocellular carcinoma(HCC). However, surgery for patients with huge( > 10 cm) HCCs is controversial. This retrospective study aimed to explore long-term survival after hepatectomy for patients with huge HCC. Methods: The records of 188 patients with pathologically confirmed HCC who underwent curative hepatectomy between 2007 and 2017 were reviewed;patients were divided into three groups according to tumor size: huge( > 10 cm;n = 84), large(5–10 cm;n = 51) and small( < 5 cm;n = 53) HCC. Kaplan-Meier analysis was used to assess overall survival(OS) and disease-free survival(DFS), and log-rank analysis was performed for pairwise comparisons among the three groups. Risk factors for survival and recurrence were analyzed using the Cox proportional hazard model. Results: The median follow-up period was 20 months. Although the prognosis of small HCC was better than that of huge and large HCC, OS and DFS were not significantly different between huge and large HCC( P = 0.099 and P = 0.831, respectively). A family history of HCC, poor Child-Pugh class, vascular invasion, diolame, pathologically positive margins, and operative time ≥240 min were identified as independent risk factors for OS and DFS in a multivariate model. Tumor size( > 10 cm) had significant effect on OS, and postoperative antiviral therapy and postoperative complications also had significant effects on DFS. Conclusions: Huge HCC is not a contraindication of hepatectomy. Although most of these patients experienced recurrence after surgery, OS and DFS were not significantly different from those of patients with large HCC after resection.

Preliminary study of a new pathological evolution-based clinical hepatolithiasis classification

AIM:To investigate clinical features,treatment strategies and outcomes of patients with hepatolithiasis(HL)undergoing surgical treatment,using a new clinicalclassification.METHODS:Sixty-eight HL patients were hospitalized and treated surgically from August 2011 to December2012 and they were classified into four HL types according to pathological evolution of the disease.These four HL types included typeⅠprimary type(defined as no previous biliary tract surgery),typeⅡinflammatory type(with previous biliary tract surgery and cholangitis),typeⅢmass-forming type(HL complicated by hepatic mass-forming lesion),and typeⅣterminal type(with secondary biliary cirrhosis and resultant portal hypertension).The perioperative data including general information,imaging data,postoperative complications,and immediate and final stone clearance rate were obtained and analyzed.RESULTS:In all 68 patients,the proportion of HL typeⅠ-Ⅳwas 50%(34/68),36.8%(25/68),10.3%(7/68)and 2.8%(2/68),respectively.Abdominal pain was the main clinical manifestation in typeⅠ(88.2%),fever was predominant in typeⅡ(52.0%),the malignancy rate in typeⅢwas high(71.4%),and portal hypertension and spleen enlargement were common in typeⅣ(2/2,100.0%).Liver resection rate for typesⅠ-Ⅲwas 79.4%,72.0%and 71.4%,respectively.The overall incidence of postoperative complications was23.5%(16/68).There were no perioperative deaths.The average length of hospital stay was 12.7±7.3 d.Immediate and final stone clearance rate was 73.5%(50/68)and 89.7%(61/68),respectively.Fifty-nine of68 patients(86.8%)were followed-up for>1 year after surgery,and 96.6%of these patients(57/59)had a good quality of life according to a criterion recommended for postoperative evaluation of quality of life.CONCLUSION:The pathological evolution-based clinical classification of HL has a role in optimizingtreatment strategy,and patients can benefit from thisclassification when it is used properly.

Clinical online nomogram for predicting prognosis in recurrent hepatolithiasis after biliary surgery:A multicenter,retrospective study

BACKGROUND Methods for predicting the prognosis of patients undergoing surgery for recurrent hepatolithiasis after biliary surgery are currently lacking.AIM To establish a nomogram to predict the prognosis of patients with recurrent hepatolithiasis after biliary surgery.METHODS In this multicenter,retrospective study,data of consecutive patients in four large medical centers who underwent surgery for recurrent hepatolithiasis after biliary surgery were retrospectively analyzed.We constructed a nomogram to predict the prognosis of recurrent hepatolithiasis in a training cohort of 299 patients,following which we independently tested the nomogram in an external validation cohort of 142 patients.Finally,we used the concordance index(C-index),calibration,area under curve,decision curve analysis,clinical impact curves,and visual fit indices to evaluate the accuracy of the nomogram.RESULTS Multiple previous surgeries[2 surgeries:Odds ratio(95%confidence interval),1.451(0.719-2.932);3 surgeries:4.573(2.015-10.378);≥4 surgeries:5.741(1.347-24.470)],bilateral hepatolithiasis[1.965(1.039-3.717)],absence of immediate clearance[2.398(1.304-4.409)],neutrophil-to-lymphocyte ratio≥2.462[1.915(1.099-3.337)],and albumin-to-globulin ratio≤1.5[1.949(1.056-3.595)]were found to be independent factors influencing the prognosis.The nomogram constructed on the basis of these variables showed good reliability in the training(C-index:0.748)and validation(C-index:0.743)cohorts.Compared with predictions using traditional classification models,those using our nomogram showed better agreement with actual observations in the calibration curve for the probability of endpoints and the receiver operating characteristic curve.Dichloroacetate and clinical impact curves showed a larger net benefit of the nomogram.CONCLUSION The nomogram developed in this study demonstrated superior performance and discriminative power compared to the three traditional classifications.It is easy to use,highly accurate,and shows excellent calibration.

Nomogram based on inflammation-related markers for predicting survival of patients undergoing hepatectomy for hepatocellular carcinoma

BACKGROUND Previous nomograms for hepatocellular carcinoma(HCC)did not include the neutrophil-to-lymphocyte ratio(NLR)or platelet-to-lymphocyte ratio(PLR).This study aimed to establish an effective nomogram capable of estimating the association between preoperative inflammatory factors and overall survival(OS)of HCC patients after hepatectomy.AIM To analyse the factors affecting the prognosis of HCC and establish a nomogram.METHODS A total of 626 HCC patients(410 training set patients from the First Affiliated Hospital of Anhui Medical University and 216 validation set patients from the First Affiliated Hospital of University of Science and Technology of China)underwent hepatectomy from January 2014 to December 2017 and were followed up every 3–6 mo.The nomogram was based on OS-related independent risk factors identified by Cox regression analysis.The C-index,calibration curve,and area under the curve(AUC)were used to evaluate the nomogram’s accuracy.RESULTS The 1-,2-and 3-year OS rates were 79.0%,68.0%and 45.4%in the training cohort(median OS=34 mo)and 92.1%,73.9%and 51.2%in the validation cohort(median OS=38 mo).Higherα-fetoprotein[hazard ratio(HR)=1.812,95%confidence interval(CI):1.343–2.444],NLR(HR=2.480,95%CI:1.856–3.312)and PLR(HR=1.974,95%CI:1.490–2.616),tumour size≥5 cm(HR=1.323,95%CI:1.002–1.747),and poor differentiation(HR=3.207,95%CI:1.944–5.290)were significantly associated with shortened OS.The developed nomogram integrating these variables showed good reliability in both the training(C-index=0.71)and validation cohorts(C-index=0.75).For predicting 1-,2-and 3-year OS,the nomogram had AUCs of 0.781,0.743 and 0.706 in the training cohort and 0.789,0.815 and 0.813 in the validation cohort.The nomogram was more accurate in predicting prognosis than the AJCC TNM staging system.CONCLUSION The prognostic nomogram combining pathological characteristics and inflammation indicators could provide a more accurate individualized risk estimate for the OS of HCC patients with hepatectomy.

High-Dimensional Spatial Standardization Algorithm for Diffusion Tensor Image Registration

Three high dimensional spatial standardization algorithms are used for diffusion tensor image(DTI)registration,and seven kinds of methods are used to evaluate their performances.Firstly,the template used in this paper was obtained by spatial transformation of 16 subjects by means of tensor-based standardization.Then,high dimensional standardization algorithms for diffusion tensor images,including fractional anisotropy(FA)based diffeomorphic registration algorithm,FA based elastic registration algorithm and tensor-based registration algorithm,were performed.Finally,7 kinds of evaluation methods,including normalized standard deviation,dyadic coherence,diffusion cross-correlation,overlap of eigenvalue-eigenvector pairs,Euclidean distance of diffusion tensor,and Euclidean distance of the deviatoric tensor and deviatoric of tensors,were used to qualitatively compare and summarize the above standardization algorithms.Experimental results revealed that the high-dimensional tensor-based standardization algorithms perform well and can maintain the consistency of anatomical structures.

Online calculator for predicting the risk of malignancy in patients with pancreatic cystic neoplasms: A multicenter, retrospective study

BACKGROUND Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms(PCNs)are lacking.AIM To establish a nomogram-based online calculator for predicting the risk of malignancy in patients with PCNs.METHODS In this study,the clinicopathological data of target patients in three medical centers were analyzed.The independent sample t-test,Mann–Whitney U test or chi-squared test were used as appropriate for statistical analysis.After univariable and multivariable logistic regression analysis,five independent factors were screened and incorporated to develop a calculator for predicting the risk of malignancy.Finally,the concordance index(C-index),calibration,area under the curve,decision curve analysis and clinical impact curves were used to evaluate the performance of the calculator.RESULTS Enhanced mural nodules[odds ratio(OR):4.314;95%confidence interval(CI):1.618–11.503,P=0.003],tumor diameter≥40 mm(OR:3.514;95%CI:1.138–10.849,P=0.029),main pancreatic duct dilatation(OR:3.267;95%CI:1.230–8.678,P=0.018),preoperative neutrophil-to-lymphocyte ratio≥2.288(OR:2.702;95%CI:1.008–7.244,P=0.048],and preoperative serum CA19-9 concentration≥34 U/mL(OR:3.267;95%CI:1.274–13.007,P=0.018)were independent risk factors for a high risk of malignancy in patients with PCNs.In the training cohort,the nomogram achieved a C-index of 0.824 for predicting the risk of malignancy.The predictive ability of the model was then validated in an external cohort(C-index:0.893).Compared with the risk factors identified in the relevant guidelines,the current model showed better predictive performance and clinical utility.CONCLUSION The calculator demonstrates optimal predictive performance for identifying the risk of malignancy,potentially yielding a personalized method for patient selection and decision-making in clinical practice.

A VMIMO-Based Cooperative Routing Algorithm for Maximizing Network Lifetime

Energy efficiency is an important criterion for routing algorithms in the wireless sensor network. Cooperative routing can reduce energy consumption effectively stemming from its diversity gain advantage. To solve the energy consumption problem and maximize the network lifetime, this paper proposes a Virtual Multiple Input Multiple Output based Cooperative Routing algorithm(VMIMOCR). VMIMOCR chooses cooperative relay nodes based on Virtual Multiple Input Multiple Output Model, and balances energy consumption by reasonable power allocation among transmitters, and decides the forwarding path finally. The experimental results show that VMIMOCR can improve network lifetime from 37% to 348% in the medium node density, compared with existing routing algorithms.

Learning discriminative representation with global and fine-grained features for cross-view gait recognition

In this study,we examine the cross-view gait recognition problem.Many existing methods establish global feature representation based on the whole human body shape.However,they ignore some important details of different parts of the human body.In the latest literature,positioning partial regions to learn fine-grained features has been verified to be effective in human identification.But they only consider coarse fine-grained fea-tures and ignore the relationship between neighboring regions.Taken the above insights together,we propose a novel model called GaitGP,which learns both important details through fine-grained features and the relationship between neighboring regions through global features.Our GaitGP model mainly consists of the following two aspects.First,we propose a Channel-Attention Feature Extractor(CAFE)to extract the global features,which aggregates the channel-level attention to enhance the spatial information in a novel convolutional component.Second,we present the Global and Partial Feature Combiner(GPFC)to learn different fine-grained features,and combine them with the global fea-tures extracted by the CAFE to obtain the relevant information between neighboring regions.Experimental results on the CASIA gait recognition dataset B(CASIA-B),The OU-ISIR gait database,multi-view large population dataset,and The OU-ISIR gait database gait datasets show that our method is superior to the state-of-the-art cross-view gait recognition methods.

Certrust:An SDN-Based Framework for the Trust of Certificates against Crossfire Attacks in IoT Scenarios

The low-intensity attack flows used by Crossfire attacks are hard to distinguish from legitimate flows.Traditional methods to identify the malicious flows in Crossfire attacks are rerouting,which is based on statistics.In these existing mechanisms,the identification of malicious flows depends on the IP address.However,the IP address is easy to be changed by attacks.Comparedwith the IP address,the certificate ismore challenging to be tampered with or forged.Moreover,the traffic trend in the network is towards encryption.The certificates are popularly utilized by IoT devices for authentication in encryption protocols.DTLShps proposed a new way to verify certificates for resource-constrained IoT devices by using the SDN controller.Based on DTLShps,the SDN controller can collect statistics on certificates.In this paper,we proposeCertrust,a framework based on the trust of certificates,tomitigate the Crossfire attack by using SDN for IoT.Our goal is threefold.First,the trust model is built based on the Bayesian trust system with the statistics on the participation of certificates in each Crossfire attack.Moreover,the forgetting curve is utilized instead of the traditional decay method in the Bayesian trust system for achieving a moderate decay rate.Second,for detecting the Crossfire attack accurately,a method based on graph connectivity is proposed.Third,several trust-based routing principles are proposed tomitigate the Crossfire attack.These principles can also encourage users to use certificates in communication.The performance evaluation shows that Certrust is more effective in mitigating the Crossfire attack than the traditional rerouting schemes.Moreover,our trust model has a more appropriate decay rate than the traditional methods.

Effects of atomic corrugations on electronic structures in Pb_(1-x)Bi_(x) thin films

We carried out experimental investigations of the geometric effect on the electronic behavior in Pb_(1-x)Bi_(x) thin films by scanning tunneling microscopy and spectroscopy.Single crystal monolayer Pb_(0.74)Bi_(0.26) and two-monolayer Pb_(0.75)Bi_(0.25)Pb_(1-x)Bi_(x) thin films were fabricated by molecular beam epitaxy,where large surface corrugations were observed.Combined with tunneling spectroscopic measurements,it is found that atomic corrugations can widely change the electronic behaviors.These findings show that the Pb_(1-x)Bi_(x) system can be a promising platform to further explore geometry-decorated electronic behavior in two-dimensional metallic thin films.

Two-dimensional Sb cluster superlattice on Si substrate fabricated by a two-step method

Nanoclusters consisting of a few atoms have attracted a lot of research interests due to their exotic size-dependent properties. Here, well-ordered two-dimensional Sb cluster superlattice was fabricated on Si substrate by a two-step method and characterized by scanning tunneling microscopy. High resolution scanning tunneling microscope measurements revealed the fine structures of the Sb clusters, which consist of several Sb atoms ranging from 2 to 7. Furthermore, the electronic structure of the nanocluster displays the quantized energy-level which is due to the single-electron tunneling effects. We believe that the fabrication of Sb cluster superlattice broadens the species of the cluster superlattice and provides a promising candidate to further explore the novel physical and chemical properties of the semimetal nanocluster.

Primary renal small cell carcinoma:A case report

BACKGROUND Small cell carcinoma(SCC)is a malignant tumour that is frequently accompanied by extensive metastasis.Primary renal SCC has typical characteristics related to SCC and is extremely rare,with no uniform treatment standard.Clinical treatment is mainly based on the literature.Here we report the diagnosis and treatment of an interesting case of primary renal SCC.CASE SUMMARY We report a tortuous course of treatment for a 68-year-old man.Four years before diagnosis,the patient developed continuous gross haematuria,during which he underwent several ureteral biopsies,ureteral stricture relief,and urine exfoliated cell examinations;however,SCC was not confirmed.One month before radical resection of the renal pelvic carcinoma,the severe haematuria recurred.Computed tomography revealed transitional cell carcinoma in the right kidney and right upper ureter.A preoperative examination exluded the possibility of a pulmonary origin of the tumour,and primary renal SCC was diagnosed.The postoperative pathology findings were suggestive of SCC.The patient was treated with combined chemotherapy but died of tumour progression at 7 mo postoperative.CONCLUSION Our patient's disease onset in the context of a succession of regular testing and the fact that it occurred so quickly with perirenal encroachment immediately after diagnosis reveals the cruel and unforgiving side of the disease.Furthermore,patients with poor comprehensive treatment results require new treatment regimens.

Thyroid follicular renal cell carcinoma excluding thyroid metastases:A case report

BACKGROUND Thyroid follicular renal cell carcinoma is a special type of renal cell carcinoma newly recognized in recent years.It has attracted attention because of its unique histology,immunophenotype,and clinical characteristics.It has a very low incidence,and the number of case reports available for review is limited.Moreover,a thyroid mass with type of tumour is rare.CASE SUMMARY We report a case of a renal mass with a bilateral thyroid mass that was accidentally discovered in a 60-year-old man during physical examination.B-mode ultrasound showed a hypoechoic mass in the middle and lower parenchyma of the right kidney,and computed tomography showed an iso-density shadow tumour in the right kidney.Contrast agents had a significant continuous enhancement effect on the tumour,and the enhancement was not uniform.After partial nephrectomy,pathological analysis was performed to rule out the possibility that the renal tumour was caused by thyroid tumour metastasis.Needle biopsy of the thyroid tumour confirmed that the renal cell carcinoma was not related to the thyroid tumour.The patient was alive at the last postoperative follow-up.CONCLUSION This is the third published case in which thyroid tumour biopsy was performed to confirm that thyroid follicular renal cell carcinoma is not thyroid related.

Based on necroptosis identifying the immunological features and prognostic signatures of lung adenocarcinoma

Background:Lung adenocarcinoma is one of the most common pathological types of lung malignant tumor with high morbidity and mortality.Long non-coding RNAs are gradually recognized to play crucial roles in tumor occurrence and development.Necroptosis is a newly established way for cell programmed death,undertaking essential roles in anti-tumor.Therefore,identifying necroptosis-related l ong non-coding RNAs and based on them to evaluate the signatures of l ung adenocarcinoma is essential for patients’survival prediction and therapy.Methods:We collected data from the public database and performed the least absolute shrinkage to construct a 13-lncRNAs prognostic model.Based on the Consensus Clustering,ESTIMATE,CIRERSORT,and weighted gene co-expression network analysis to identify the immune signatures.Results:This study identified a 13-lncRNAs prognostic model.The model’s prediction accuracy was evaluated by receiver operating characteristic and independent-prognosis analysis;besides,a Gene Expression Omnibus dataset was applied for external validation.Furthermore,we analyzed the immune features of subgroups in multiple dimensions.A consensus clustering analysis based on the 41 genes was implemented to separate lung adenocarcinoma patients into two subgroups.We compared the features of subgroups in multiple dimensions,including survival,immune microenvironment,immune cells infiltration and gene co-expression network analysis.Conclusion:W e established a prognosis necroptosis-related risk model to predict lung adenocarcinoma patients’prognosis and systematically understood the correlation between immune and necroptosis.This study can applicate in clinical to predict the prognosis of lung adenocarcinoma patients and provide new insight into lung adenocarcinoma immune therapy.

A complete reference genome assembly for foxtail millet and Setaria-db, a comprehensive database for Setaria

Dear Editor,,Foxtail millet(Setaria italica)and its wild ancestor green foxtail(S.viridis),are two C4 genetic model plants known for their desirable traits,such as small size,short life cycle,ease of transformation,and a compact genome size(~420 Mb)(He et al.,2023).Foxtail millet stands out as the only cultivated species within the Setaria genus.As a foundational crop for ancient east Asian agriculture civilization,it possesses remarkable drought and soil-nutrient deficiency tolerance.

过渡金属化合物表界面调控对超级电容的增强机制

开发效率高、稳定性好的超级电容器对于缓解能源危机和环境污染问题具有重要意义。过渡金属化合物通过法拉第氧化还原反应存储电荷,具有更高的比容量。然而,其面临导电性差、反应动力学缓慢和暴露的电活性位点少等问题,在实践应用中存在一定的困难。本文针对过渡金属化合物存在的问题,总结了形貌调控、异质结构、元素掺杂、空位工程等表界面调控策略在提升超级电容器电化学性能方面的研究进展。重点从几何结构和电子结构调控角度探讨上述方法对活性材料物理和化学性质的作用机理,进一步揭示超级电容器性能的增强机制,为研制高性能、高稳定性超级电容器提供理论基础。最后,总结结构设计和电子调控提高超级电容器性能的原因,展望了结构设计和电子调控在构筑高性能超级电容器方面面临的挑战。

Interplay between the atomic structures and superconductivity of two-monolayer Pb films

Superconductors with reduced dimensionality have been widely explored for their exotic superconducting behaviors.Especially,at the two-dimensional limit,two-monolayer Pb films with two types of structures provide an ideal platform to unveil the underlying superconducting mechanism[Science 324,1314(2009)].Here,by combining scanning tunneling microscopy(STM)with the first-principle calculations,we successfully identify that these two types have different atomic lattice structures with varying stacking phases,which further enables us to calculate the phonon spectrum and electron phonon coupling strength of each type.The theoretical calculations are in good agreement with tunneling spectroscopy measurements of the superconducting transition temperatures(T_(c)),which established a correlation between atomic structures and superconductivity.Moreover,it was observed that the higher T_(c)of these two types also possess higher out-of-plane upper critical magnetic fields(Hc2).These findings will provide important new insights into two-dimensional superconductivity at the atomic level.