In response to the challenges presented by the unreliable identity of the master node,high communication overhead,and limited network support size within the Practical Byzantine Fault-Tolerant(PBFT)algorithm for conso...In response to the challenges presented by the unreliable identity of the master node,high communication overhead,and limited network support size within the Practical Byzantine Fault-Tolerant(PBFT)algorithm for consortium chains,we propose an improved PBFT algorithm based on XGBoost grouping called XG-PBFT in this paper.XG-PBFT constructs a dataset by training important parameters that affect node performance,which are used as classification indexes for nodes.The XGBoost algorithm then is employed to train the dataset,and nodes joining the system will be grouped according to the trained grouping model.Among them,the nodes with higher parameter indexes will be assigned to the consensus group to participate in the consensus,and the rest of the nodes will be assigned to the general group to receive the consensus results.In order to reduce the resource waste of the system,XG-PBFT optimizes the consensus protocol for the problem of high complexity of PBFT communication.Finally,we evaluate the performance of XG-PBFT.The experimental results show that XG-PBFT can significantly improve the performance of throughput,consensus delay and communication complexity compared to the original PBFT algorithm,and the performance enhancement is significant compared to other algorithms in the case of a larger number of nodes.The results demonstrate that the XG-PBFT algorithm is more suitable for large-scale consortium chains.展开更多
The rapid development of mega low earth orbit(LEO)satellite networks is expected to have a significant impact on 6G networks.Unlike terrestrial networks,due to the high-speed movement of satellites,users will frequent...The rapid development of mega low earth orbit(LEO)satellite networks is expected to have a significant impact on 6G networks.Unlike terrestrial networks,due to the high-speed movement of satellites,users will frequently hand over between satellites even if their positions remain unchanged.Furthermore,the extensive coverage characteristic of satellites leads to massive users executing handovers simultaneously.To address these challenges,we propose a novel double grouping-based group handover scheme(DGGH)specifically tailored for mega LEO satellite networks.First,we develop a user grouping strategy based on beam-limited hierarchical clustering to divide users into distinct groups.Next,we reframe the challenge of managing multiple users’simultaneous handovers as a single-objective optimization problem,solving it with a satellite grouping strategy that leverages the accuracy of greedy algorithms and the simplicity of dynamic programming.Additionally,we develop a group handover algorithm based on minimal handover waiting time to improve the satellite grouping process further.The detailed steps of the DGGH scheme’s handover procedure are meticulously outlined.Comprehensive simulations show that the proposed DGGH scheme outperforms single-user handover schemes in terms of handover signaling over-head and handover success rate.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divide...Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature.展开更多
The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impac...The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.展开更多
Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic...Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.展开更多
THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’...THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’s long-standing reverence for fire.Originating from the Yi ancestors’worship of fire,the festival was intended to drive away pests and evil spirits,protect crops,and represent prayers for a bountiful harvest.展开更多
The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a su...The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.展开更多
To further explore the human visual system（ HVS）,the perceptual grouping（ PG）, which has been proven to play an important role in the HVS, is adopted to design an effective image quality assessment（ IQA） model. ...To further explore the human visual system（ HVS）,the perceptual grouping（ PG）, which has been proven to play an important role in the HVS, is adopted to design an effective image quality assessment（ IQA） model. Compared with the existing fixed-window-based models, the proposed one is an adaptive window-like model that introduces the perceptual grouping strategy into the IQA model. It works as follows： first,it preprocesses the images by clustering similar pixels into a group to the greatest extent; then the structural similarity is used to compute the similarity of the superpixels between reference and distorted images; finally, it integrates all the similarity of superpixels of an image to yield a quality score. Experimental results on three databases（ LIVE, IVC and MICT） showthat the proposed method yields good performance in terms of correlation with human judgments of visual quality.展开更多
A new approach was proposed for grouping separation of 14 lanthanide rare-earth ions from their coexisting mixed aqueous solutions, by performing liquid-column elution using the aqueous solution containing 14 lanthani...A new approach was proposed for grouping separation of 14 lanthanide rare-earth ions from their coexisting mixed aqueous solutions, by performing liquid-column elution using the aqueous solution containing 14 lanthanide rare-earth ions as the stationary phase and the dispersed organic oil droplets containing P507 extractant as the mobile phase. It was revealed that 14 lanthanide rare-earth ions could be separated into four groups, according to the lanthanide tetrad effect, respectively eluting out from the liquid column at different time in a certain order. Various effects including the saponification degree of P507, the concentration of P507 in organic phase, the length and inner diameter of the extraction column on the performance of grouping separation of rare-earth ions were discussed. The changes of the mass transfer coefficients were also investigated. The separation efficiency of the four groups of rareearth elements(REEs) was evaluated based on the elution resolution, Rs, of the elution peaks of La(Ⅲ),Gd(Ⅲ), Ho(Ⅲ) and Lu(Ⅲ), the four representative elements respectively from each of the four groups of REEs. Experimental results demonstrated that the separation of REEs by liquid-column elution mainly depended on the competitive adsorption of different rare-earth groups onto the surface of ascending P507 oil droplets. The affinity of different rare-earth groups with P507 extractant and a limited adsorption capacity of P507 molecules at the surface of the oil droplets ascending in liquid column play the important role. The present work highlights a promising technique for grouping separation of multiple lanthanide elements co-existing complex systems.展开更多
Wind loading is one of the most important loads for controlling the design of large-span roof structures. Equivalent static wind loads, which can generally aim at determining a specific response, are widely used by st...Wind loading is one of the most important loads for controlling the design of large-span roof structures. Equivalent static wind loads, which can generally aim at determining a specific response, are widely used by structural designers. A method for equivalent static wind loads applicable to multi-responses is proposed in this paper. A modified load- response-correlation （LRC） method corresponding to a particular peak response is presented, and the similarity algorithm implemented for the group response is described. The main idea of the algorithm is that two responses can be put into one group if the value of one response is close to that of the other response, when the structure is subjected to equivalent static wind loads aiming at the other response. Based on the modified LRC, the grouping response method is put forward to construct equivalent static wind loading. This technique can simultaneously reproduce peak responses for some grouped responses. To verify its computational accuracy, the method is applied to an actual large-span roof structure. Calculation results show that when the similarity of responses in the same group is high, equivalent static wind loads with high accuracy and reasonable magnitude of equivalent static wind distribution can be achieved.展开更多
BACKGROUND:Imaging examination is important for hepatic cirrhosis.But the relationship between magnetic resonance(MR),computed tomography(CT)or ultrasound findings and pathological groups,degree,or reserve function of...BACKGROUND:Imaging examination is important for hepatic cirrhosis.But the relationship between magnetic resonance(MR),computed tomography(CT)or ultrasound findings and pathological groups,degree,or reserve function of the cirrhotic liver is not clear.In this study,we investigated the relationship between the CT groupings of liver cirrhosis and its complications and clinical conditions.METHODS:The CT findings in 357 patients with liver cirrhosis were grouped.The complications were analyzed,included splenomegaly,varicose collateral veins,ascites,pleurorrhea,primary liver carcinoma,gallbladder stone,etc.Blood routine(BRt),and serum usea nitrogen(SUN),creatinine and uric acid were measured and hypersplenia and liver-kidney syndrome were estimated.RESULTS:Three hundred and fifty-seven patients with cirrhosis were divided into homogeneous group(87 patients,24.4%),segmental group(41,11.5%),and nodal group(229,64.2%).The grade of spleen enlargement in the segmental and the nodal groups was significantly greater than that in the homogeneous group(P<0.01 and P<0.001).The patients with varices were shown in a descending order in the segmental group(70.7%),the nodal group(17.0%)and the homogeneous group(2.3%),respectively.Significant difference was observed among the 3 groups(P<0.001).Ascites was seen in 182 patients(79.5%)of the nodal group,in 11 patients(26.8%)of the segmental group and in 9 patients(10.3%)of the homogeneous group(P<0.001).Sixty-eight patients(29.7%)in the nodal group had primary liver carcinoma and 1(2.4%)in the segmental group and 5(5.8%)in the homogeneous group(P<0.001).The number of patients with decreased concentration of hematoglobin in the nodal group was more than that in the homogeneous group(P<0.001).The mean values of hematoglobin and platelet in the nodal group and the segmental group were significantly lower than those in the homogeneous group(P<0.05).The number of patients with increased concentration of SUN in the nodal group and the segmental group was more than that in the homogeneous group(P<0.005).The concentration of SUN in the nodal group was significantly higher than that in the homogeneous group(P<0.002).CONCLUSION:There is a close relationship between the grouping of liver cirrhosis by CT findings and complications caused by the cirrhosis.The grouping is significant for estimating clinical conditions.展开更多
Linear wave theory and Longuet-Higgins and Steward’s (1964) group-induced second-order longweve (GSLW) theory ware used in this study on the grouping effect on wave forces acting on a verticalbreakwater. The calculat...Linear wave theory and Longuet-Higgins and Steward’s (1964) group-induced second-order longweve (GSLW) theory ware used in this study on the grouping effect on wave forces acting on a verticalbreakwater. The calculated variance of total wave pressure on the vertical breakwater was closer tothe measured value if the wave grouping effect was considered.展开更多
Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological ...Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological characteristics, making their morphological identification very difficult. In addition, few of the species diversity in this genus has been described before. In this study, phylogenetic analysis based on rbc L gene sequence was employed to group Grateloupia collected from three locations along Chinese coast. The microsatellites were also used to evaluate their genetic diversity. In total, the tissue parts of 6 putative species were collected from G. asiatica, G. livida, G. lanceolate, G. catenata, G. turuturu and G. filicina. In order to evaluate their genetic diversity and then conserve them better, 40 microsatellites available for Grateloupia were used to evaluate their genetic diversity, and 11 microsatellites were found to be applicable to determine the genetic diversity of G. asiatica. It was found that the genetic diversity of G. asiatica around Qingdao was very rich. We suggested that the species of genus Grateloupia should be identified based on rbc L phylogenetic analysis before the diversity evaluation with microsatellites. The microsatellites should be developed for each species of Grateloupia so that their genetic diversity can be evaluated appropriately.展开更多
The grouping of sensors is a calculation method for partitioning the wireless sensor network into groups, each group consisting of a collection of sensors. A sensor can be an element of multiple groups. In the present...The grouping of sensors is a calculation method for partitioning the wireless sensor network into groups, each group consisting of a collection of sensors. A sensor can be an element of multiple groups. In the present paper, we will show a model to divide the wireless sensor network sensors into groups. These groups could communicate and work together in a cooperative way in order to save the time of routing and energy of WSN. In addition, we will present a way to show how to organize the sensors in groups and provide a combinatorial analysis of some issues related to the performance of the network.展开更多
AIM： To figure out the contributed factors of the hospitalization expenses of senile cataract patients（HECP） and build up an area-specified senile cataract diagnosis related group（DRG） of Shanghai thereby formula...AIM： To figure out the contributed factors of the hospitalization expenses of senile cataract patients（HECP） and build up an area-specified senile cataract diagnosis related group（DRG） of Shanghai thereby formulating the reference range of HECP and providing scientific basis for the fair use and supervision of the health care insurance fund.METHODS： The data was collected from the first page of the medical records of 22 097 hospitalized patients from tertiary hospitals in Shanghai from 2010 to 2012 whose major diagnosis were senile cataract. Firstly, we analyzed the influence factors of HECP using univariate and multivariate analysis. DRG grouping was conducted according to the exhaustive Chi-squared automatic interaction detector（E-CHAID） model, using HECP as target variable. Finally we evaluated the grouping results using non-parametric test such as Kruskal-Wallis H test, RIV, CV, etc.RESULTS： The 6 DRGs were established as well as criterion of HECP, using age, sex, type of surgery and whether complications/comorbidities occurred as the key variables of classification node of senile cataract cases.CONCLUSION： The grouping of senile cataract cases based on E-CHAID algorithm is reasonable. And the criterion of HECP based on DRG can provide a feasible way of management in the fair use and supervision of medical insurance fund.展开更多
BACKGROUND In 2018,the diagnosis-related groups prospective payment system(DRGs-PPS)was introduced in a trial operation in Beijing according to the requirements of medical and health reform.The implementation of the s...BACKGROUND In 2018,the diagnosis-related groups prospective payment system(DRGs-PPS)was introduced in a trial operation in Beijing according to the requirements of medical and health reform.The implementation of the system requires that more than 300 disease types pay through the DRGs-PPS for medical insurance.Colorectal cancer(CRC),as a common malignant tumor with high prevalence in recent years,was among the 300 disease types.AIM To investigate the composition and factors related to inpatient medical expenditure in CRC patients based on disease DRGs,and to provide a basis for the rational economic control of hospitalization expenses for the diagnosis and treatment of CRC.METHODS The basic material and cost data for 1026 CRC inpatients in a Grade-A tertiary hospital in Beijing during 2014-2018 were collected using the medical record system.A variance analysis of the composition of medical expenditure was carried out,and a multivariate linear regression model was used to select influencing factors with the greatest statistical significance.A decision tree model based on the exhaustiveχ^2 automatic interaction detector(E-CHAID)algorithm for DRG grouping was built by setting chosen factors as separation nodes,and the payment standard of each diagnostic group and upper limit cost were calculated.The correctness and rationality of the data were re-evaluated and verified by clinical practice.RESULTS The average hospital stay of the 1026 CRC patients investigated was 18.5 d,and the average hospitalization cost was 57872.4 RMB yuan.Factors including age,gender,length of hospital stay,diagnosis and treatment,as well as clinical operations had significant influence on inpatient expenditure(P<0.05).By adopting age,diagnosis,treatment,and surgery as the grouping nodes,a decision tree model based on the E-CHAID algorithm was established,and the CRC patients were divided into 12 DRG cost groups.Among these 12 groups,the number of patients aged≤67 years,and underwent surgery and chemotherapy or radiotherapy was largest;while patients aged>67 years,and underwent surgery and chemotherapy or radiotherapy had the highest medical cost.In addition,the standard cost and upper limit cost in the 12 groups were calculated and re-evaluated.CONCLUSION It is important to strengthen the control over the use of drugs and management of the hospitalization process,surgery,diagnosis and treatment to reduce the economic burden on patients.Tailored adjustments to medical payment standards should be made according to the characteristics and treatment of disease types to improve the comprehensiveness and practicability of the DRGs-PPS.展开更多
The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E...The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E) and its adjacent area up to 1991 were analyzed systematically.These earthquakes are called as strong earthquakes and those of the east before and after 1600,and those of the west before and after 1900, are called respectively as former ones and latter ones.Most of these events were divided into 45 sets of which the each relatively concentrated in both time and space and took the form of group.In the grouping form,the probability of occurrence of a strong earthquake higher than the average appeared simultaneously in time and space.The grouping occurrences of the strong earthquakes of Chinese mainland has been determined as a fundamental feature of the seismicity.展开更多
文摘In response to the challenges presented by the unreliable identity of the master node,high communication overhead,and limited network support size within the Practical Byzantine Fault-Tolerant(PBFT)algorithm for consortium chains,we propose an improved PBFT algorithm based on XGBoost grouping called XG-PBFT in this paper.XG-PBFT constructs a dataset by training important parameters that affect node performance,which are used as classification indexes for nodes.The XGBoost algorithm then is employed to train the dataset,and nodes joining the system will be grouped according to the trained grouping model.Among them,the nodes with higher parameter indexes will be assigned to the consensus group to participate in the consensus,and the rest of the nodes will be assigned to the general group to receive the consensus results.In order to reduce the resource waste of the system,XG-PBFT optimizes the consensus protocol for the problem of high complexity of PBFT communication.Finally,we evaluate the performance of XG-PBFT.The experimental results show that XG-PBFT can significantly improve the performance of throughput,consensus delay and communication complexity compared to the original PBFT algorithm,and the performance enhancement is significant compared to other algorithms in the case of a larger number of nodes.The results demonstrate that the XG-PBFT algorithm is more suitable for large-scale consortium chains.
基金supported in part by the State Key Laboratory of Micro-Spacecraft Rapid Design and Intelligent Cluster(No.MS01240103)the National Natural Science Foundation of China(No.62071146,No.62431009)+1 种基金the National 2011 Collaborative Innovation Center of Wireless Communication Technologies(No.2242022k60006)the Research Project Fund of Songjiang Laboratory(No.SL20230104).
文摘The rapid development of mega low earth orbit(LEO)satellite networks is expected to have a significant impact on 6G networks.Unlike terrestrial networks,due to the high-speed movement of satellites,users will frequently hand over between satellites even if their positions remain unchanged.Furthermore,the extensive coverage characteristic of satellites leads to massive users executing handovers simultaneously.To address these challenges,we propose a novel double grouping-based group handover scheme(DGGH)specifically tailored for mega LEO satellite networks.First,we develop a user grouping strategy based on beam-limited hierarchical clustering to divide users into distinct groups.Next,we reframe the challenge of managing multiple users’simultaneous handovers as a single-objective optimization problem,solving it with a satellite grouping strategy that leverages the accuracy of greedy algorithms and the simplicity of dynamic programming.Additionally,we develop a group handover algorithm based on minimal handover waiting time to improve the satellite grouping process further.The detailed steps of the DGGH scheme’s handover procedure are meticulously outlined.Comprehensive simulations show that the proposed DGGH scheme outperforms single-user handover schemes in terms of handover signaling over-head and handover success rate.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金Supported by the National Natural Science Foundation of China(Grant No.12071092)Guangdong Basic and Applied Basic Research Foundation(Grant No.2025A1515012072)+1 种基金the Natural Science Research Project of Anhui Educational Committee(Grant No.2024AH051298)the Scientific Research Foundation of Bozhou University(Grant No.BYKQ202419).
文摘Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature.
基金financially supported by the National Natural Science Foundation of China (Nos.22375024,21975031,51933001,and 21734009)。
文摘The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.
文摘Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.
文摘THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’s long-standing reverence for fire.Originating from the Yi ancestors’worship of fire,the festival was intended to drive away pests and evil spirits,protect crops,and represent prayers for a bountiful harvest.
基金supported by the National Natural Science Foundation of China(42372250,42102262 and 41972235)National Key Research and Development Program Project(2023YFF0803701)+1 种基金Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP206)the program of China Scholarship Council。
文摘The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.
基金The National Natural Science Foundation of China(No.81272501)the National Basic Research Program of China(973Program)(No.2011CB707904)Taishan Scholars Program of Shandong Province,China(No.ts20120505)
文摘To further explore the human visual system（ HVS）,the perceptual grouping（ PG）, which has been proven to play an important role in the HVS, is adopted to design an effective image quality assessment（ IQA） model. Compared with the existing fixed-window-based models, the proposed one is an adaptive window-like model that introduces the perceptual grouping strategy into the IQA model. It works as follows： first,it preprocesses the images by clustering similar pixels into a group to the greatest extent; then the structural similarity is used to compute the similarity of the superpixels between reference and distorted images; finally, it integrates all the similarity of superpixels of an image to yield a quality score. Experimental results on three databases（ LIVE, IVC and MICT） showthat the proposed method yields good performance in terms of correlation with human judgments of visual quality.
基金Supported by the National Natural Science Foundation of China(51574213,51074150)the Key Project of Chinese National Programs for Fundamental Research and Development(2012CBA01203)
文摘A new approach was proposed for grouping separation of 14 lanthanide rare-earth ions from their coexisting mixed aqueous solutions, by performing liquid-column elution using the aqueous solution containing 14 lanthanide rare-earth ions as the stationary phase and the dispersed organic oil droplets containing P507 extractant as the mobile phase. It was revealed that 14 lanthanide rare-earth ions could be separated into four groups, according to the lanthanide tetrad effect, respectively eluting out from the liquid column at different time in a certain order. Various effects including the saponification degree of P507, the concentration of P507 in organic phase, the length and inner diameter of the extraction column on the performance of grouping separation of rare-earth ions were discussed. The changes of the mass transfer coefficients were also investigated. The separation efficiency of the four groups of rareearth elements(REEs) was evaluated based on the elution resolution, Rs, of the elution peaks of La(Ⅲ),Gd(Ⅲ), Ho(Ⅲ) and Lu(Ⅲ), the four representative elements respectively from each of the four groups of REEs. Experimental results demonstrated that the separation of REEs by liquid-column elution mainly depended on the competitive adsorption of different rare-earth groups onto the surface of ascending P507 oil droplets. The affinity of different rare-earth groups with P507 extractant and a limited adsorption capacity of P507 molecules at the surface of the oil droplets ascending in liquid column play the important role. The present work highlights a promising technique for grouping separation of multiple lanthanide elements co-existing complex systems.
基金Ministry of Science and Technology of China Under Grant No.SLDRCE10-B-04the National Natural Science Foundation Under Grant No.50621062
文摘Wind loading is one of the most important loads for controlling the design of large-span roof structures. Equivalent static wind loads, which can generally aim at determining a specific response, are widely used by structural designers. A method for equivalent static wind loads applicable to multi-responses is proposed in this paper. A modified load- response-correlation （LRC） method corresponding to a particular peak response is presented, and the similarity algorithm implemented for the group response is described. The main idea of the algorithm is that two responses can be put into one group if the value of one response is close to that of the other response, when the structure is subjected to equivalent static wind loads aiming at the other response. Based on the modified LRC, the grouping response method is put forward to construct equivalent static wind loading. This technique can simultaneously reproduce peak responses for some grouped responses. To verify its computational accuracy, the method is applied to an actual large-span roof structure. Calculation results show that when the similarity of responses in the same group is high, equivalent static wind loads with high accuracy and reasonable magnitude of equivalent static wind distribution can be achieved.
文摘BACKGROUND:Imaging examination is important for hepatic cirrhosis.But the relationship between magnetic resonance(MR),computed tomography(CT)or ultrasound findings and pathological groups,degree,or reserve function of the cirrhotic liver is not clear.In this study,we investigated the relationship between the CT groupings of liver cirrhosis and its complications and clinical conditions.METHODS:The CT findings in 357 patients with liver cirrhosis were grouped.The complications were analyzed,included splenomegaly,varicose collateral veins,ascites,pleurorrhea,primary liver carcinoma,gallbladder stone,etc.Blood routine(BRt),and serum usea nitrogen(SUN),creatinine and uric acid were measured and hypersplenia and liver-kidney syndrome were estimated.RESULTS:Three hundred and fifty-seven patients with cirrhosis were divided into homogeneous group(87 patients,24.4%),segmental group(41,11.5%),and nodal group(229,64.2%).The grade of spleen enlargement in the segmental and the nodal groups was significantly greater than that in the homogeneous group(P<0.01 and P<0.001).The patients with varices were shown in a descending order in the segmental group(70.7%),the nodal group(17.0%)and the homogeneous group(2.3%),respectively.Significant difference was observed among the 3 groups(P<0.001).Ascites was seen in 182 patients(79.5%)of the nodal group,in 11 patients(26.8%)of the segmental group and in 9 patients(10.3%)of the homogeneous group(P<0.001).Sixty-eight patients(29.7%)in the nodal group had primary liver carcinoma and 1(2.4%)in the segmental group and 5(5.8%)in the homogeneous group(P<0.001).The number of patients with decreased concentration of hematoglobin in the nodal group was more than that in the homogeneous group(P<0.001).The mean values of hematoglobin and platelet in the nodal group and the segmental group were significantly lower than those in the homogeneous group(P<0.05).The number of patients with increased concentration of SUN in the nodal group and the segmental group was more than that in the homogeneous group(P<0.005).The concentration of SUN in the nodal group was significantly higher than that in the homogeneous group(P<0.002).CONCLUSION:There is a close relationship between the grouping of liver cirrhosis by CT findings and complications caused by the cirrhosis.The grouping is significant for estimating clinical conditions.
文摘Linear wave theory and Longuet-Higgins and Steward’s (1964) group-induced second-order longweve (GSLW) theory ware used in this study on the grouping effect on wave forces acting on a verticalbreakwater. The calculated variance of total wave pressure on the vertical breakwater was closer tothe measured value if the wave grouping effect was considered.
基金supported by the Marine Industry Research Special Funds for Public Welfare Projects(No.201205024)
文摘Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological characteristics, making their morphological identification very difficult. In addition, few of the species diversity in this genus has been described before. In this study, phylogenetic analysis based on rbc L gene sequence was employed to group Grateloupia collected from three locations along Chinese coast. The microsatellites were also used to evaluate their genetic diversity. In total, the tissue parts of 6 putative species were collected from G. asiatica, G. livida, G. lanceolate, G. catenata, G. turuturu and G. filicina. In order to evaluate their genetic diversity and then conserve them better, 40 microsatellites available for Grateloupia were used to evaluate their genetic diversity, and 11 microsatellites were found to be applicable to determine the genetic diversity of G. asiatica. It was found that the genetic diversity of G. asiatica around Qingdao was very rich. We suggested that the species of genus Grateloupia should be identified based on rbc L phylogenetic analysis before the diversity evaluation with microsatellites. The microsatellites should be developed for each species of Grateloupia so that their genetic diversity can be evaluated appropriately.
文摘The grouping of sensors is a calculation method for partitioning the wireless sensor network into groups, each group consisting of a collection of sensors. A sensor can be an element of multiple groups. In the present paper, we will show a model to divide the wireless sensor network sensors into groups. These groups could communicate and work together in a cooperative way in order to save the time of routing and energy of WSN. In addition, we will present a way to show how to organize the sensors in groups and provide a combinatorial analysis of some issues related to the performance of the network.
基金Supported by the Key Research and Development Program of Hunan Province(No.2017SK2011)
文摘AIM： To figure out the contributed factors of the hospitalization expenses of senile cataract patients（HECP） and build up an area-specified senile cataract diagnosis related group（DRG） of Shanghai thereby formulating the reference range of HECP and providing scientific basis for the fair use and supervision of the health care insurance fund.METHODS： The data was collected from the first page of the medical records of 22 097 hospitalized patients from tertiary hospitals in Shanghai from 2010 to 2012 whose major diagnosis were senile cataract. Firstly, we analyzed the influence factors of HECP using univariate and multivariate analysis. DRG grouping was conducted according to the exhaustive Chi-squared automatic interaction detector（E-CHAID） model, using HECP as target variable. Finally we evaluated the grouping results using non-parametric test such as Kruskal-Wallis H test, RIV, CV, etc.RESULTS： The 6 DRGs were established as well as criterion of HECP, using age, sex, type of surgery and whether complications/comorbidities occurred as the key variables of classification node of senile cataract cases.CONCLUSION： The grouping of senile cataract cases based on E-CHAID algorithm is reasonable. And the criterion of HECP based on DRG can provide a feasible way of management in the fair use and supervision of medical insurance fund.
文摘BACKGROUND In 2018,the diagnosis-related groups prospective payment system(DRGs-PPS)was introduced in a trial operation in Beijing according to the requirements of medical and health reform.The implementation of the system requires that more than 300 disease types pay through the DRGs-PPS for medical insurance.Colorectal cancer(CRC),as a common malignant tumor with high prevalence in recent years,was among the 300 disease types.AIM To investigate the composition and factors related to inpatient medical expenditure in CRC patients based on disease DRGs,and to provide a basis for the rational economic control of hospitalization expenses for the diagnosis and treatment of CRC.METHODS The basic material and cost data for 1026 CRC inpatients in a Grade-A tertiary hospital in Beijing during 2014-2018 were collected using the medical record system.A variance analysis of the composition of medical expenditure was carried out,and a multivariate linear regression model was used to select influencing factors with the greatest statistical significance.A decision tree model based on the exhaustiveχ^2 automatic interaction detector(E-CHAID)algorithm for DRG grouping was built by setting chosen factors as separation nodes,and the payment standard of each diagnostic group and upper limit cost were calculated.The correctness and rationality of the data were re-evaluated and verified by clinical practice.RESULTS The average hospital stay of the 1026 CRC patients investigated was 18.5 d,and the average hospitalization cost was 57872.4 RMB yuan.Factors including age,gender,length of hospital stay,diagnosis and treatment,as well as clinical operations had significant influence on inpatient expenditure(P<0.05).By adopting age,diagnosis,treatment,and surgery as the grouping nodes,a decision tree model based on the E-CHAID algorithm was established,and the CRC patients were divided into 12 DRG cost groups.Among these 12 groups,the number of patients aged≤67 years,and underwent surgery and chemotherapy or radiotherapy was largest;while patients aged>67 years,and underwent surgery and chemotherapy or radiotherapy had the highest medical cost.In addition,the standard cost and upper limit cost in the 12 groups were calculated and re-evaluated.CONCLUSION It is important to strengthen the control over the use of drugs and management of the hospitalization process,surgery,diagnosis and treatment to reduce the economic burden on patients.Tailored adjustments to medical payment standards should be made according to the characteristics and treatment of disease types to improve the comprehensiveness and practicability of the DRGs-PPS.
文摘The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E) and its adjacent area up to 1991 were analyzed systematically.These earthquakes are called as strong earthquakes and those of the east before and after 1600,and those of the west before and after 1900, are called respectively as former ones and latter ones.Most of these events were divided into 45 sets of which the each relatively concentrated in both time and space and took the form of group.In the grouping form,the probability of occurrence of a strong earthquake higher than the average appeared simultaneously in time and space.The grouping occurrences of the strong earthquakes of Chinese mainland has been determined as a fundamental feature of the seismicity.
