Mechano luminescence(ML),which involves the emission of light under mechanical stimuli,shows great potential in various applications such as sensing,imaging,and energy harvesting.Current research suggests that the lum...Mechano luminescence(ML),which involves the emission of light under mechanical stimuli,shows great potential in various applications such as sensing,imaging,and energy harvesting.Current research suggests that the luminescence mechanism of ML is typically connected to specific defects present within the material.In this study,we focus on the investigation of ML defects in Pr^(3+)-doped NaNbO_(3)/LiNbO_(3)heterojunctions,employing a combination of experimental and theoretical approaches.Through experimental analysis,we confirmed the presence of the heterojunction and its influence on ML intensity,and the optimal doping ratio for the heterojunction in ML was established.Furthermore,we examined the influence of varying Pr^(3+)doping concentrations on ML behavior and a proof-of-concept was demonstrated using the X-rays charged heterostructural phosphor as a stress sensor for biological applications.The position and concentration of internal defects in the ML material were scrutinized through thermo luminescence tests employing the variable heating rate method and positron annihilation.Complementing the experimental findings,theoretical simulations were conducted to elucidate the underlying mechanisms responsible for the observed ML defects.Density functional theory calculations were employed to investigate the energy levels,charge transfer processes,and lattice distortions within the heterojunctions under mechanical stress.Theoretical predictions were compared and validated against the experimental results.The integration of experimental and theoretical approaches provides a comprehensive understanding of the ML behavior of Pr^(3+)-doped NaNbO_(3)/LiNbO_(3)heterojunctions.The insights gained from this research contribute to the development of novel ML materials and pave the way for their applications in next-generation sensing and energy conversion devices.展开更多
This paper presents a novel neuro-adaptive cellular immunotherapy control strategy that leverages the high efficiency and applicability of chimeric antigen receptor-engineered T(CAR-T)cells in treating cancer.The prop...This paper presents a novel neuro-adaptive cellular immunotherapy control strategy that leverages the high efficiency and applicability of chimeric antigen receptor-engineered T(CAR-T)cells in treating cancer.The proposed real-time control strategy aims to maximize tumor regression while ensuring the safety of the treatment.A dynamic growth model of cancer cells under the influence of cellular immunotherapy is established for the first time,which aligns with clinical experimental results.Utilizing the backstepping method,a novel consensus reference model is designed to consider the characteristics of cancer cell changes during the treatment process and conform to clinical rules.The model is segmented and continuous,with cancer cells expected to decrease in a step-like manner.Furthermore,a prescribed performance mechanism is constructed to maintain the therapeutic effect of the proposed scheme while ensuring the transient performance of the system.Through the analysis of Lyapunov stability,all signals within the closed-loop system are proven to be semiglobally uniformly ultimately bounded(SGUUB).Simulation results demonstrate the effectiveness of the proposed control strategy,highlighting its potential for clinical application in cancer treatment.展开更多
Purpose–As an important part of the management of railway passenger transport,the rationality and effectiveness of the clearing method of railway passenger transport are directly related to the operating efficiency a...Purpose–As an important part of the management of railway passenger transport,the rationality and effectiveness of the clearing method of railway passenger transport are directly related to the operating efficiency and service quality of railway passenger transport enterprises.This paper aims to comprehensively and deeply discuss the evolution and development process of China’s railway passenger transport clearing method,analyze its characteristics and influences in each stage,identify the main factors affecting its evolution and development and then put forward thoughts on improving the future development of the clearing method.Design/methodology/approach–Through a detailed review of the railway passenger transport clearing methods from the planned economy period to the reform and opening up period and into the new century,the basis,mode,subject and object of clearing in different development stages are systematically compared.Findings–It comprehensively reveals the evolution of the clearing method,sorted out the characteristics and changes of the clearing method at each stage and the adaptability to the development of railway passenger transport at that time.The characteristics of the development of clearing measures for railway passenger transport in different stages and their far-reaching influence on railway passenger transport business are deeply analyzed.Originality/value–This paper summarized the factors influencing the development of China’s railway passenger transportation clearing approach evolution,including the simplified rules of clearing,enhanced the market adaptability,establishing and perfecting the incentive mechanism,strengthening the construction of informatization,etc.This paper puts forward the ways to improve the railway passenger transportation clearing future development thinking.展开更多
Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictiv...Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictive relationship between the workability and mechanical properties of UHPFRC. Specifically, the addition of fibers will affect the workability of fresh UHPFRC, and the workability of fresh UHPFRC will also affect the dispersion and arrangement of fibers, thus significantly influencing the mechanical properties of hardened UHPFRC. This paper first analyzes the research status of UHPFRC and the relationship between its workability and mechanical properties. Subsequently, it outlines the test methods and indicators of UHPFRC workability, including fluidity, slump, V-funnel passing time, and rheology. Then, it reviews the impacts of metal fibers, synthetic fibers, hybrid fibers, and other fibers on the workability and mechanical properties of UHPFRC, and presents a reasonable range of fiber dosage for workability and mechanical properties. Key findings include: (1) Steel fibers within 1%–2% volume optimize workability-mechanical balance, while exceeding 2.5% reduces compressive strength by 7%–30%;(2) Hybrid steel-polypropylene fibers enhance toughness by 65%;(3) Fiber orientation control via rheology-modifying admixtures improves flexural strength by up to 64%. This review establishes a fiber factor (V·L/D) for predictive mix design, advancing beyond empirical approaches in prior studies.展开更多
This article is concerned with a strongly coupled elliptic system modeling the steady state of two or more populations that compete in some regions. We prove the uniqueness of the limiting configuration as the competi...This article is concerned with a strongly coupled elliptic system modeling the steady state of two or more populations that compete in some regions. We prove the uniqueness of the limiting configuration as the competing rate tends to infinity, under suitable conditions. The proof relies on properties of limiting solution and Maximum principle.展开更多
Objective: To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety,Methods: Acute toxicity was determined by oral administration of a single dose of 18 100 mg/kg forsythin in NIH mic...Objective: To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety,Methods: Acute toxicity was determined by oral administration of a single dose of 18 100 mg/kg forsythin in NIH mice,Sub-chronic toxicity was evaluated by oral administration of several doses of forsythin for 30 days at does of 0,540,1 620,and 6 480 mg/kg in SD rats.Results: In the acute toxicity study,mortality was not observed after 14 days,In addition,clinically relevant adverse effects,or variations in body weight or food consumption were not observed,Similarly,after 30 days in the sub-chronic toxicity study,no mortality or significant toxicological effects such as decreased food consumption,body weight,biochemical parameters and vital organs etc,were noticed,Conclusion: The results revealed that the forsythin from Forsythia suspensa leaves has low or no toxicity via oral administration,and therefore is suitable for further development and applications.展开更多
This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated...This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated glucogalactan,with a hypothetical backbone structure of→4)Gα(1→6)G4 Sβ(1→4)Glc(1→and a side chain of Man(1→6)Glc.PHP2 had an irregular spherical chain conformation.The 16 S r RNA sequence analysis revealed that PHP2 modulated the rat fecal micro-flora composition,with a similar effect to inulin,changing the dominant genus(Lactobacillus and Escherichia-Shigella)and promoting the growth of organisms that degrade sulfur-containing polysaccharides,such as Desulfovibrio,Ruminococcaceae_UCG-005,and Ruminococcus_2.PHP2 can promote production of acetic,propionic and butyric acid by rat fecal micro-flora.Prediction of metabolic function suggested that PHP2 could modulate cholesterol metabolism.The sulfated glucogalactan fermentation behavior may be associated with its monosaccharide composition,chain branching and chain conformation.PHP2 appeared to have considerable potential as functional food,and was associated with sulfur-containing polysaccharides in general.展开更多
Recently, the online social networks have emerged as one of the important platforms for social users. Among millions of users, famous person from entertainment circle arouse our interest. They promote social relations...Recently, the online social networks have emerged as one of the important platforms for social users. Among millions of users, famous person from entertainment circle arouse our interest. They promote social relationship and establish their reputation via these platforms. To analyze the social influence of entertainment stars we propose and implement a public cloud based framework to crawl celebrities' social messages from Sina Weibo, store the gathered messages and conduct various analysis to assess the socia influence. It consist of three key components: task generation, resource management and task scheduling, and influence analysis. The task generation is responsible of acquiring celebrities' socia accounts and issue crawling tasks. We propose a cross-media method to extract social accounts from webpages. The resource management and task scheduling will dynamic adjust the rented resource to minimize the total computing cost while keeping Qo S. We propose a dynamic instance provisioning strategy based on the large deviation principle. The influence analysis will undertake various types of analysis, such as fan count, posting frequency, textual analysis, and so on. More than 10,000 celebrities' microblogs have been gathered so far, and some related gainers, such as celebrities and ad agencies can gain the illumination brought by our analysis.展开更多
Background:Lung cancer is one of the most lethal cancers worldwide,but studies have shown that the higher the expression of programmed cell death protein 1 ligand 1(PD-L1)in non-small cell lung cancer(NSCLC),the more ...Background:Lung cancer is one of the most lethal cancers worldwide,but studies have shown that the higher the expression of programmed cell death protein 1 ligand 1(PD-L1)in non-small cell lung cancer(NSCLC),the more likely it will benefit from anti-PD-L1 immunotherapy.The purpose of our study was to collect and analyze abundant clinical samples in order to provide evidence for clinicians and patients who might consider anti-PD-L1 immunotherapy while jointly formulating treatment plans.Methods:On the one hand,we obtained cases from The Cancer Genome Atlas(TCGA)database,including 498 lung squamous cell cancer(LUSC)patients and 515 lung adenocarcinoma(LUAD)patients.We studied the lung caner driver gene in LUSC and LUAD.On the other hand,PD-L1 expression was detected in lung cancer tissues of 1,008 NSCLC patients with immunohistochemistry staining(IHC),and we studied the correlation between PD-L1 protein expression and clinicopathological characteristics.Results:PD-L1 expression was higher in LUSC than in LUAD at the mRNA level.In univariate analysis,PD-L1 expression at the protein level was higher in patients who were males,were LUSC,were smokers,had a tumor diameter>3 cm,had poor differentiation,or had stages Ⅲ-Ⅳ disease.In multivariate analysis,PD-L1 expression was higher in patients who were LUSC or in poor differentiation.Conclusion:In term of protein level,PD-L1 expression was higher in NSCLC patients who were LUSC or in poor differentiation.We recommend that PD-L1 IHC detection can be routinely performed in such populations that are likely to benefit most from PD-L1 immunotherapy.展开更多
A three-dimensional transformed Eulerian-mean(3D TEM) equation under a non-hydrostatic and non-geostrophic assumption is deduced in this study. The vertical component of the 3D wave activity flux deduced here is the p...A three-dimensional transformed Eulerian-mean(3D TEM) equation under a non-hydrostatic and non-geostrophic assumption is deduced in this study. The vertical component of the 3D wave activity flux deduced here is the primary difference from previous studies, which is suitable to mesoscale systems. Using the 3D TEM equation, the energy propagation of the inertia–gravity waves and how the generation and dissipation of the inertia–gravity waves drive the mean flow can be examined. During the mature stage of a heavy precipitation event, the maximum of the Eliassen–Palm(EP) flux divergence is primarily concentrated at the height of 10–14 km, where the energy of the inertia–gravity waves propagates forward(eastward) and upward. Examining the contribution of each term of the 3D TEM equation shows that the EP flux divergence is the primary contributor to the mean flow tendency. The EP flux divergence decelerates the zonal wind above and below the high-level jet at the height of 10 km and 15 km, and accelerates the high-level jet at the height of 12–14 km. This structure enhances the vertical wind shear of the environment and promotes the development of the rainstorm.展开更多
NCEP-NCAR reanalysis data were used to analyze the characteristics and evolution mechanism of convective and symmetric instability before and during a heavy rainfall event that occurred in Beijing on 21 July 2012.Appr...NCEP-NCAR reanalysis data were used to analyze the characteristics and evolution mechanism of convective and symmetric instability before and during a heavy rainfall event that occurred in Beijing on 21 July 2012.Approximately twelve hours before the rainstorm,the atmosphere was mainly dominated by convective instability in the lower level of 900-800 hPa.The strong southwesterly low-level jet conveyed the moist and warm airflow continuously to the area of torrential rain,maintaining and enhancing the unstable energy.When the precipitation occurred,unstable energy was released and the convective instability weakened.Meanwhile,due to the baroclinicity enhancement in the atmosphere,the symmetric instability strengthened,maintaining and promoting the subsequent torrential rain.Deriving the convective instability tendency equation demonstrated that the barotropic component of potential divergence and the advection term played a major role in enhancing the convective instability before the rainstorm.Analysis of the tendency equation of moist potential vorticity showed that the coupled term of vertical vorticity and the baroclinic component of potential divergence was the primary factor influencing the development of symmetric instability during the precipitation.Comparing the effects of these factors on convective instability and symmetric instability showed some correlation.展开更多
The use of traditional finite element method(FEM)in occlusal stress analysis is limited due to the complexity of musculature simulation.The present purpose was to develop a displacement boundary condition(DBC)-FEM,whi...The use of traditional finite element method(FEM)in occlusal stress analysis is limited due to the complexity of musculature simulation.The present purpose was to develop a displacement boundary condition(DBC)-FEM,which evaded the muscle factor,to predict the dynamic occlusal stress.The geometry of the DBC-FEM was developed based on the scanned plastic casts obtained from a volunteer.The electrognathographic and video recorded jaw positional messages were adopted to analyze the dynamic occlusal stress.The volunteer exhibited asymmetrical lateral movements,so that the occlusal stress was further analyzed by using the parameters obtained from the right-side eccentric movement,which was 6.9 mm long,in the stress task of the left-side eccentric movement,which was 4.1 mm long.Further,virtual occlusion modification was performed by using the carving tool software aiming to improve the occlusal morphology at the loading sites.T-Scan Occlusal System was used as a control of the in vivo detection for the location and strength of the occlusal contacts.Data obtained from the calculation using the present developed DBC-FEM indicated that the stress distribution on the dental surface changed dynamically with the occlusal contacts.Consistent with the T-Scan recordings,the right-side molars always showed contacts and higher levels of stress.Replacing the leftside eccentric movement trace by the right-side one enhanced the simulated stress on the right-side molars while modification of the right-side molars reduced the simulated stress.The present DBC-FEM offers a creative approach for pragmatic occlusion stress prediction.展开更多
Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods C...Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods Cancellous bone were extracted from rabbit femoral head and cut into I-ram-thick and 8-ram-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000 με respectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase （AKP） and tartrate-resistant acid phosphatase （TRAP） were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection. Results After being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000 με were significantly lower than those in the unstressed bone tissues （all P〈0.05）. DNA ladders were seen in the bone tissue under 3000 and 4000με mechanical load. Moreover, there was significant enhancement in the activities of caspase-3/8/9 in the mechanical stress group of 3000 and 4000 με （all P〈0.05）. Conclusions The cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteobiasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000 με.展开更多
The design and fabrication of rare earth ions incorporated into the inorganic/organic hybrid materials have attracted growing attention for seeking improved optical properties and photofunctional performances.In this ...The design and fabrication of rare earth ions incorporated into the inorganic/organic hybrid materials have attracted growing attention for seeking improved optical properties and photofunctional performances.In this paper,a novel hybrid composite based on the layered rare earth hydroxides was successfully prepared by the ion-exchange and intercalation chemical process.The rare earth elements in the composite contain gadolinium(Gd)and europium(Eu)and the molar ratio of Gd to Eu is kept constant at 1.9:0.1.Organic sodium dodecyl sulfonate and dye coumarin-3-carboxyllc acid are simultaneously incorporated into the layered rare earth hydroxides as supporting agent and light-harvesting antenna,respectively.The resulting hybrid layered rare earth hydroxides exhibit the enlarged interlayer distance with about 2.60 nm,and the chemical composition was confirmed through X-ray diffraction,carbon,hydrogen and nitrogen(CHN)elemental analysis,infrared spectroscopy,and thermogravimetric analysis.The layered solid compound shows the characteristic red emission corresponding to the^(5)D_(0)→^(7)F_(2)transition of Eu^(3+)ion,and the luminescence intensity of the optimized compound is greatly enhanced as compared to its corresponding nitrate and the hybrid composite without the introduction of dye molecule.The hybrid layered rare earth hydroxides can be exfoliated into bright colloidal solution,which show superior recognition capability to Cu^(2+)ion with the distinct luminescence quenching.The large quenching constant(1.4×10^(4)L/mol)and low detection limit(0.35μmol/L)are achieved for Cu^(2+)ion,implying a"turn-off"fluorescent sensor for Cu^(2+)detection.Moreover,a transparent film was prepared based on the colloidal solution and displays the typical red emission in folded shape.The new hybrid compound with enhanced luminescence and excellent photofunctional performances is expected to be applied in the fields of fluorescent sensing and flexible optical devices.展开更多
Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to ...Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to 2019.The research fully considers the system’s internal and external inputs and outputs and proposes an evaluation index system for regional EECE coupling and coordinated development.Then,using the difference in system weight allocation to improve the coupling and coordination model,the study explores the dynamic system’s coupling and coordination.The results show that(1)The development of the system structure is relatively stable,but the overall development status is not ideal;(2)The downstream of China’s main river basins has obvious economic advantages,while the energy system fluctuates greatly.The efficiency of the carbon emission system will decrease in areas with rapid economic development.The coupling and coordination level of the EECE system is better in the Yangtze River Basin than in the Yellow River Basin;(3)From the perspective of dynamic coordinated development,the main river basins have been divided into two states since 2012,but it is relatively stable overall.Regional dynamic coordination is often at a disadvantage in regions with rapid economic and energy development;(4)The coupling coordination degree of the two river basins has significant positive spatial autocorrelation.Most provinces’significant spatial clustering characteristics of the coupling coordination degree are High-High type.Low-Low type provinces are mainly concentrated downstream.The research process has certain reference significance for the collaborative governance of complex regional systems.展开更多
Bitcoin is a cryptocurrency based on blockchain.All historical Bitcoin transactions are stored in the Bitcoin blockchain,but Bitcoin owners are generally unknown.This is the reason for Bitcoin's pseudo-anonymity,t...Bitcoin is a cryptocurrency based on blockchain.All historical Bitcoin transactions are stored in the Bitcoin blockchain,but Bitcoin owners are generally unknown.This is the reason for Bitcoin's pseudo-anonymity,therefore it is often used for illegal transactions.Bitcoin addresses are related to Bitcoin users'identities.Some Bitcoin addresses have the potential to be analyzed due to the behavior patterns of Bitcoin transactions.However,existing Bitcoin analysis methods do not consider the fusion of new blocks'data,resulting in low efficiency of Bitcoin address analysis.In order to address this problem,this paper proposes an incremental Bitcoin address cluster method to avoid re-clustering when new block data is added.Besides,a heuristic Bitcoin address clustering algorithm is developed to improve clustering accuracy for the Bitcoin Blockchain.Experimental results show that the proposed method increases Bitcoin address cluster efficiency and accuracy.展开更多
To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Vv＇uhan during November 2015. Fifteen fog water samples were collected by using a three-st...To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Vv＇uhan during November 2015. Fifteen fog water samples were collected by using a three-stage Caltech Active Strand Cloud water Collector （CASCC）. The three-stage CASCC was mounted on the board of a ship. PH, electrical conductivity （EC）, H202, HCHO, S（ll0, ten inorganic ions, seven organicacids and sixteen trace metal elements were measured in this study. The pH of fog water samples ranged from weakly acidic （pH 4.3） to weakly alkaline （pH 7.05） and the EC ranged from 32.4 to 436.3 μS/cm. The main cations in fog water were NH^4＋ and Ca2＋, accounting for 12.35% and 29.07% of those inorganic ions, respectively. In addition, SO24- and NO^-3 contributed to 25.52% and 12.93% to total anion concentrations respectively. Moreover, the dominant kinds of organicacids were formate and oxalate, occupying 45.28% and 28.03% of the total organicacids, respectively. For trace metal elements in fog samples, Al, Fe, Zn, and Ba revealed 34.6%, 16.4%, 19.3%, and 20.9% contributions to these sixteen trace element concentrations, respectively. The results indicated that pollutants were mainly from human activities, including fossil fuel combustion, biomass burning, steel-making, stone quarrying and sand digging. Besides, natural sources including natural background levels and long-range transport of sea salt particles also aggravated the pollution levels in the fog events along the Yangtze River.展开更多
Pyrylium salts are a type of representative and convincing example of versatility and variety not only as a nodal point in organic transformations but also as an attractive building block in functional organic materia...Pyrylium salts are a type of representative and convincing example of versatility and variety not only as a nodal point in organic transformations but also as an attractive building block in functional organic materials. Herein, we report an effective synthetic protocol to fabricate a new pyrylium-containing porous organic polymers(POPs), named TMP-P, via Knoevenagel condensation with 2,4,6-trimethylpyrylium salt(TMP) as the key building block and 1,4-phthalaldehyde as the linker. The resulting ionic polymer TMPP exhibited efficient visible-light-driven heterogeneous photodegradation of Rhodamine B, owing to the presence of wide visible light absorption and a narrow optical band gap triggered pyrylium core in the framework.展开更多
The waters near the Antarctic Peninsula have always been a study hot spot because of their variable and unique oceanographic conditions.To determine the distribution and possible influencing factors on phytoplankton s...The waters near the Antarctic Peninsula have always been a study hot spot because of their variable and unique oceanographic conditions.To determine the distribution and possible influencing factors on phytoplankton size and abundance near the Antarctic Peninsula,a large-scale survey was conducted during the austral summer of2018.Samples were collected in 27 stations located in the Drake Passage(DP),South Shetland Islands(SSI),and South Orkney Islands(SOI).Phytoplankton communities were described using chlorophyll a(Chl a),flow cytometry and light microscopy to cover a size range from pico-to microphytoplankton.Nanophytoplankton,especially small nanophytoplankton(2-6μm)with abundance ranging from 0.66×10^(3) cells/mL to 8.46×10^(3) cells/mL,was predominant throughout the study area.Among different regions,there was an obvious size shift.The proportion of picophytoplankton near the Elephant Island(EI)and DP was higher than other regions,and larger cells were found mainly in east of SOI.The distribution of phytoplankton abundance detected by flow cytometry was not completely consistent with Chl a concentrations due to the contribution of larger cells to Chl a.Possible influencing factors on the phytoplankton size distribution were discussed.The properties of water masses such as temperature and salinity can influence the phytoplankton size distribution.Correlation analysis revealed that only picophytoplankton is significantly correlated with salinity.Light and Fe availability might affect phytoplankton abundance and size distribution especially near the waters of SSI and EI in this study.It was also speculated that the abundance of cryptophytes is possibly related to ice melting.展开更多
基金supported by the National Natural Science Foundation of China(52201008,52372003)Natural Science Foundation of Heilongjiang Province of China(ZD2023E004)+1 种基金Fundamental Research Funds for the Central Universities(3072020CF2515,3072022CFJ2504)the State Key Laboratory of Particle Detection and Electronics(SKLPDE-KF-202311)。
文摘Mechano luminescence(ML),which involves the emission of light under mechanical stimuli,shows great potential in various applications such as sensing,imaging,and energy harvesting.Current research suggests that the luminescence mechanism of ML is typically connected to specific defects present within the material.In this study,we focus on the investigation of ML defects in Pr^(3+)-doped NaNbO_(3)/LiNbO_(3)heterojunctions,employing a combination of experimental and theoretical approaches.Through experimental analysis,we confirmed the presence of the heterojunction and its influence on ML intensity,and the optimal doping ratio for the heterojunction in ML was established.Furthermore,we examined the influence of varying Pr^(3+)doping concentrations on ML behavior and a proof-of-concept was demonstrated using the X-rays charged heterostructural phosphor as a stress sensor for biological applications.The position and concentration of internal defects in the ML material were scrutinized through thermo luminescence tests employing the variable heating rate method and positron annihilation.Complementing the experimental findings,theoretical simulations were conducted to elucidate the underlying mechanisms responsible for the observed ML defects.Density functional theory calculations were employed to investigate the energy levels,charge transfer processes,and lattice distortions within the heterojunctions under mechanical stress.Theoretical predictions were compared and validated against the experimental results.The integration of experimental and theoretical approaches provides a comprehensive understanding of the ML behavior of Pr^(3+)-doped NaNbO_(3)/LiNbO_(3)heterojunctions.The insights gained from this research contribute to the development of novel ML materials and pave the way for their applications in next-generation sensing and energy conversion devices.
基金supported in part by the National Natural Science Foundation of China(62203097)the National High-Level Talents Special Support Program(Youth Talent of Technological Innovation of TenThousands Talents Program)(QNBJ-2023-12)the Fundamental Research Funds for the Central Universities(N2404018)
文摘This paper presents a novel neuro-adaptive cellular immunotherapy control strategy that leverages the high efficiency and applicability of chimeric antigen receptor-engineered T(CAR-T)cells in treating cancer.The proposed real-time control strategy aims to maximize tumor regression while ensuring the safety of the treatment.A dynamic growth model of cancer cells under the influence of cellular immunotherapy is established for the first time,which aligns with clinical experimental results.Utilizing the backstepping method,a novel consensus reference model is designed to consider the characteristics of cancer cell changes during the treatment process and conform to clinical rules.The model is segmented and continuous,with cancer cells expected to decrease in a step-like manner.Furthermore,a prescribed performance mechanism is constructed to maintain the therapeutic effect of the proposed scheme while ensuring the transient performance of the system.Through the analysis of Lyapunov stability,all signals within the closed-loop system are proven to be semiglobally uniformly ultimately bounded(SGUUB).Simulation results demonstrate the effectiveness of the proposed control strategy,highlighting its potential for clinical application in cancer treatment.
基金supported by the Research and Development Plan Project of China State Railway Group Co.,Ltd.(Project No.P2023X029).
文摘Purpose–As an important part of the management of railway passenger transport,the rationality and effectiveness of the clearing method of railway passenger transport are directly related to the operating efficiency and service quality of railway passenger transport enterprises.This paper aims to comprehensively and deeply discuss the evolution and development process of China’s railway passenger transport clearing method,analyze its characteristics and influences in each stage,identify the main factors affecting its evolution and development and then put forward thoughts on improving the future development of the clearing method.Design/methodology/approach–Through a detailed review of the railway passenger transport clearing methods from the planned economy period to the reform and opening up period and into the new century,the basis,mode,subject and object of clearing in different development stages are systematically compared.Findings–It comprehensively reveals the evolution of the clearing method,sorted out the characteristics and changes of the clearing method at each stage and the adaptability to the development of railway passenger transport at that time.The characteristics of the development of clearing measures for railway passenger transport in different stages and their far-reaching influence on railway passenger transport business are deeply analyzed.Originality/value–This paper summarized the factors influencing the development of China’s railway passenger transportation clearing approach evolution,including the simplified rules of clearing,enhanced the market adaptability,establishing and perfecting the incentive mechanism,strengthening the construction of informatization,etc.This paper puts forward the ways to improve the railway passenger transportation clearing future development thinking.
基金financed by Guangxi Transportation Science and Technology Achievement Promotion Project(GXJT-YFZX-2024-01-01):Intelligent Detection and Data Application R&D Center for Guangxi Transportation Industry.
文摘Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictive relationship between the workability and mechanical properties of UHPFRC. Specifically, the addition of fibers will affect the workability of fresh UHPFRC, and the workability of fresh UHPFRC will also affect the dispersion and arrangement of fibers, thus significantly influencing the mechanical properties of hardened UHPFRC. This paper first analyzes the research status of UHPFRC and the relationship between its workability and mechanical properties. Subsequently, it outlines the test methods and indicators of UHPFRC workability, including fluidity, slump, V-funnel passing time, and rheology. Then, it reviews the impacts of metal fibers, synthetic fibers, hybrid fibers, and other fibers on the workability and mechanical properties of UHPFRC, and presents a reasonable range of fiber dosage for workability and mechanical properties. Key findings include: (1) Steel fibers within 1%–2% volume optimize workability-mechanical balance, while exceeding 2.5% reduces compressive strength by 7%–30%;(2) Hybrid steel-polypropylene fibers enhance toughness by 65%;(3) Fiber orientation control via rheology-modifying admixtures improves flexural strength by up to 64%. This review establishes a fiber factor (V·L/D) for predictive mix design, advancing beyond empirical approaches in prior studies.
文摘This article is concerned with a strongly coupled elliptic system modeling the steady state of two or more populations that compete in some regions. We prove the uniqueness of the limiting configuration as the competing rate tends to infinity, under suitable conditions. The proof relies on properties of limiting solution and Maximum principle.
基金supported by the Basic Science Research Program of Guangdong Province Science and Technology Plan Projects Fund[grant numbers:2016A010119136]the High-level Leading Talent Introduction Program of GDAS[grant numbers:2016GDASRC-0104]
文摘Objective: To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety,Methods: Acute toxicity was determined by oral administration of a single dose of 18 100 mg/kg forsythin in NIH mice,Sub-chronic toxicity was evaluated by oral administration of several doses of forsythin for 30 days at does of 0,540,1 620,and 6 480 mg/kg in SD rats.Results: In the acute toxicity study,mortality was not observed after 14 days,In addition,clinically relevant adverse effects,or variations in body weight or food consumption were not observed,Similarly,after 30 days in the sub-chronic toxicity study,no mortality or significant toxicological effects such as decreased food consumption,body weight,biochemical parameters and vital organs etc,were noticed,Conclusion: The results revealed that the forsythin from Forsythia suspensa leaves has low or no toxicity via oral administration,and therefore is suitable for further development and applications.
基金supported by the Scientific Research Foundation of Graduate School of Fujian Agriculture and Forestry University(1122yb065)the Program for Leading Talent in Fujian Provincial University(660160190)。
文摘This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated glucogalactan,with a hypothetical backbone structure of→4)Gα(1→6)G4 Sβ(1→4)Glc(1→and a side chain of Man(1→6)Glc.PHP2 had an irregular spherical chain conformation.The 16 S r RNA sequence analysis revealed that PHP2 modulated the rat fecal micro-flora composition,with a similar effect to inulin,changing the dominant genus(Lactobacillus and Escherichia-Shigella)and promoting the growth of organisms that degrade sulfur-containing polysaccharides,such as Desulfovibrio,Ruminococcaceae_UCG-005,and Ruminococcus_2.PHP2 can promote production of acetic,propionic and butyric acid by rat fecal micro-flora.Prediction of metabolic function suggested that PHP2 could modulate cholesterol metabolism.The sulfated glucogalactan fermentation behavior may be associated with its monosaccharide composition,chain branching and chain conformation.PHP2 appeared to have considerable potential as functional food,and was associated with sulfur-containing polysaccharides in general.
基金supported by the Soft Science Research Program of Science&Technology Department of Sichuan Province(2016ZR0097)
文摘Recently, the online social networks have emerged as one of the important platforms for social users. Among millions of users, famous person from entertainment circle arouse our interest. They promote social relationship and establish their reputation via these platforms. To analyze the social influence of entertainment stars we propose and implement a public cloud based framework to crawl celebrities' social messages from Sina Weibo, store the gathered messages and conduct various analysis to assess the socia influence. It consist of three key components: task generation, resource management and task scheduling, and influence analysis. The task generation is responsible of acquiring celebrities' socia accounts and issue crawling tasks. We propose a cross-media method to extract social accounts from webpages. The resource management and task scheduling will dynamic adjust the rented resource to minimize the total computing cost while keeping Qo S. We propose a dynamic instance provisioning strategy based on the large deviation principle. The influence analysis will undertake various types of analysis, such as fan count, posting frequency, textual analysis, and so on. More than 10,000 celebrities' microblogs have been gathered so far, and some related gainers, such as celebrities and ad agencies can gain the illumination brought by our analysis.
基金supported by the Fundamental Research Funds for the Central Universities of Central South University(Grant 2021zzts1026).
文摘Background:Lung cancer is one of the most lethal cancers worldwide,but studies have shown that the higher the expression of programmed cell death protein 1 ligand 1(PD-L1)in non-small cell lung cancer(NSCLC),the more likely it will benefit from anti-PD-L1 immunotherapy.The purpose of our study was to collect and analyze abundant clinical samples in order to provide evidence for clinicians and patients who might consider anti-PD-L1 immunotherapy while jointly formulating treatment plans.Methods:On the one hand,we obtained cases from The Cancer Genome Atlas(TCGA)database,including 498 lung squamous cell cancer(LUSC)patients and 515 lung adenocarcinoma(LUAD)patients.We studied the lung caner driver gene in LUSC and LUAD.On the other hand,PD-L1 expression was detected in lung cancer tissues of 1,008 NSCLC patients with immunohistochemistry staining(IHC),and we studied the correlation between PD-L1 protein expression and clinicopathological characteristics.Results:PD-L1 expression was higher in LUSC than in LUAD at the mRNA level.In univariate analysis,PD-L1 expression at the protein level was higher in patients who were males,were LUSC,were smokers,had a tumor diameter>3 cm,had poor differentiation,or had stages Ⅲ-Ⅳ disease.In multivariate analysis,PD-L1 expression was higher in patients who were LUSC or in poor differentiation.Conclusion:In term of protein level,PD-L1 expression was higher in NSCLC patients who were LUSC or in poor differentiation.We recommend that PD-L1 IHC detection can be routinely performed in such populations that are likely to benefit most from PD-L1 immunotherapy.
文摘A three-dimensional transformed Eulerian-mean(3D TEM) equation under a non-hydrostatic and non-geostrophic assumption is deduced in this study. The vertical component of the 3D wave activity flux deduced here is the primary difference from previous studies, which is suitable to mesoscale systems. Using the 3D TEM equation, the energy propagation of the inertia–gravity waves and how the generation and dissipation of the inertia–gravity waves drive the mean flow can be examined. During the mature stage of a heavy precipitation event, the maximum of the Eliassen–Palm(EP) flux divergence is primarily concentrated at the height of 10–14 km, where the energy of the inertia–gravity waves propagates forward(eastward) and upward. Examining the contribution of each term of the 3D TEM equation shows that the EP flux divergence is the primary contributor to the mean flow tendency. The EP flux divergence decelerates the zonal wind above and below the high-level jet at the height of 10 km and 15 km, and accelerates the high-level jet at the height of 12–14 km. This structure enhances the vertical wind shear of the environment and promotes the development of the rainstorm.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41175060 and 41375052)the Key Program of the Chinese Academy of Sciences (Grant No. KZZD-EW-05)+1 种基金the National Basic Research Program of China (Grant No. 2013CB430105)the State Key Laboratory of Severe Weather (LASW),Chinese Academy of Meteorological Sciences (Grant No. 2013LASW-A06)
文摘NCEP-NCAR reanalysis data were used to analyze the characteristics and evolution mechanism of convective and symmetric instability before and during a heavy rainfall event that occurred in Beijing on 21 July 2012.Approximately twelve hours before the rainstorm,the atmosphere was mainly dominated by convective instability in the lower level of 900-800 hPa.The strong southwesterly low-level jet conveyed the moist and warm airflow continuously to the area of torrential rain,maintaining and enhancing the unstable energy.When the precipitation occurred,unstable energy was released and the convective instability weakened.Meanwhile,due to the baroclinicity enhancement in the atmosphere,the symmetric instability strengthened,maintaining and promoting the subsequent torrential rain.Deriving the convective instability tendency equation demonstrated that the barotropic component of potential divergence and the advection term played a major role in enhancing the convective instability before the rainstorm.Analysis of the tendency equation of moist potential vorticity showed that the coupled term of vertical vorticity and the baroclinic component of potential divergence was the primary factor influencing the development of symmetric instability during the precipitation.Comparing the effects of these factors on convective instability and symmetric instability showed some correlation.
基金supported by the National Natural Science Foundation of China(No.81530033,81920108013)。
文摘The use of traditional finite element method(FEM)in occlusal stress analysis is limited due to the complexity of musculature simulation.The present purpose was to develop a displacement boundary condition(DBC)-FEM,which evaded the muscle factor,to predict the dynamic occlusal stress.The geometry of the DBC-FEM was developed based on the scanned plastic casts obtained from a volunteer.The electrognathographic and video recorded jaw positional messages were adopted to analyze the dynamic occlusal stress.The volunteer exhibited asymmetrical lateral movements,so that the occlusal stress was further analyzed by using the parameters obtained from the right-side eccentric movement,which was 6.9 mm long,in the stress task of the left-side eccentric movement,which was 4.1 mm long.Further,virtual occlusion modification was performed by using the carving tool software aiming to improve the occlusal morphology at the loading sites.T-Scan Occlusal System was used as a control of the in vivo detection for the location and strength of the occlusal contacts.Data obtained from the calculation using the present developed DBC-FEM indicated that the stress distribution on the dental surface changed dynamically with the occlusal contacts.Consistent with the T-Scan recordings,the right-side molars always showed contacts and higher levels of stress.Replacing the leftside eccentric movement trace by the right-side one enhanced the simulated stress on the right-side molars while modification of the right-side molars reduced the simulated stress.The present DBC-FEM offers a creative approach for pragmatic occlusion stress prediction.
基金Supported by grants from the National Natural Science Foundation Key Project of China(10832012)the National Natural Science Foundation of China(31370942 and 11072266)
文摘Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods Cancellous bone were extracted from rabbit femoral head and cut into I-ram-thick and 8-ram-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000 με respectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase （AKP） and tartrate-resistant acid phosphatase （TRAP） were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection. Results After being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000 με were significantly lower than those in the unstressed bone tissues （all P〈0.05）. DNA ladders were seen in the bone tissue under 3000 and 4000με mechanical load. Moreover, there was significant enhancement in the activities of caspase-3/8/9 in the mechanical stress group of 3000 and 4000 με （all P〈0.05）. Conclusions The cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteobiasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000 με.
基金Project supported by the National Natural Science Foundation of China(51972097)。
文摘The design and fabrication of rare earth ions incorporated into the inorganic/organic hybrid materials have attracted growing attention for seeking improved optical properties and photofunctional performances.In this paper,a novel hybrid composite based on the layered rare earth hydroxides was successfully prepared by the ion-exchange and intercalation chemical process.The rare earth elements in the composite contain gadolinium(Gd)and europium(Eu)and the molar ratio of Gd to Eu is kept constant at 1.9:0.1.Organic sodium dodecyl sulfonate and dye coumarin-3-carboxyllc acid are simultaneously incorporated into the layered rare earth hydroxides as supporting agent and light-harvesting antenna,respectively.The resulting hybrid layered rare earth hydroxides exhibit the enlarged interlayer distance with about 2.60 nm,and the chemical composition was confirmed through X-ray diffraction,carbon,hydrogen and nitrogen(CHN)elemental analysis,infrared spectroscopy,and thermogravimetric analysis.The layered solid compound shows the characteristic red emission corresponding to the^(5)D_(0)→^(7)F_(2)transition of Eu^(3+)ion,and the luminescence intensity of the optimized compound is greatly enhanced as compared to its corresponding nitrate and the hybrid composite without the introduction of dye molecule.The hybrid layered rare earth hydroxides can be exfoliated into bright colloidal solution,which show superior recognition capability to Cu^(2+)ion with the distinct luminescence quenching.The large quenching constant(1.4×10^(4)L/mol)and low detection limit(0.35μmol/L)are achieved for Cu^(2+)ion,implying a"turn-off"fluorescent sensor for Cu^(2+)detection.Moreover,a transparent film was prepared based on the colloidal solution and displays the typical red emission in folded shape.The new hybrid compound with enhanced luminescence and excellent photofunctional performances is expected to be applied in the fields of fluorescent sensing and flexible optical devices.
基金supported by the Chengdu University of Technology“Double First-Class”initiative Construction Philosophy and Social Sciences Key Construction Project(No.ZDJS202202)the Research on the realization path and strategy of strategic mineral resources supply security under the new road of Chinese modernization(No.SCKCZY2023-ZD002)The Second Tibetan Plateau Scientific Expedition and Research(No.2021QZKK0305)。
文摘Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to 2019.The research fully considers the system’s internal and external inputs and outputs and proposes an evaluation index system for regional EECE coupling and coordinated development.Then,using the difference in system weight allocation to improve the coupling and coordination model,the study explores the dynamic system’s coupling and coordination.The results show that(1)The development of the system structure is relatively stable,but the overall development status is not ideal;(2)The downstream of China’s main river basins has obvious economic advantages,while the energy system fluctuates greatly.The efficiency of the carbon emission system will decrease in areas with rapid economic development.The coupling and coordination level of the EECE system is better in the Yangtze River Basin than in the Yellow River Basin;(3)From the perspective of dynamic coordinated development,the main river basins have been divided into two states since 2012,but it is relatively stable overall.Regional dynamic coordination is often at a disadvantage in regions with rapid economic and energy development;(4)The coupling coordination degree of the two river basins has significant positive spatial autocorrelation.Most provinces’significant spatial clustering characteristics of the coupling coordination degree are High-High type.Low-Low type provinces are mainly concentrated downstream.The research process has certain reference significance for the collaborative governance of complex regional systems.
基金The work reported in this paper has been partially supported by the National Key Research and Development Project(2020YFB1005503)the NSFC Projects(61502209 and U1836116)+2 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation(BK20202001)the NSFC of Jiangsu Province Project(BK20201415)the UK-Jiangsu 20-20 World Class University Initiative programme,and the Natural Science Foundation of the Jiangsu Higher Education Institutions(Grant number:22KJB520016).
文摘Bitcoin is a cryptocurrency based on blockchain.All historical Bitcoin transactions are stored in the Bitcoin blockchain,but Bitcoin owners are generally unknown.This is the reason for Bitcoin's pseudo-anonymity,therefore it is often used for illegal transactions.Bitcoin addresses are related to Bitcoin users'identities.Some Bitcoin addresses have the potential to be analyzed due to the behavior patterns of Bitcoin transactions.However,existing Bitcoin analysis methods do not consider the fusion of new blocks'data,resulting in low efficiency of Bitcoin address analysis.In order to address this problem,this paper proposes an incremental Bitcoin address cluster method to avoid re-clustering when new block data is added.Besides,a heuristic Bitcoin address clustering algorithm is developed to improve clustering accuracy for the Bitcoin Blockchain.Experimental results show that the proposed method increases Bitcoin address cluster efficiency and accuracy.
基金supported by the National Natural Science Foundation of China (Nos. 41605113, 41375126)the Taishan Scholar Grand (No. ts20120552)
文摘To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Vv＇uhan during November 2015. Fifteen fog water samples were collected by using a three-stage Caltech Active Strand Cloud water Collector （CASCC）. The three-stage CASCC was mounted on the board of a ship. PH, electrical conductivity （EC）, H202, HCHO, S（ll0, ten inorganic ions, seven organicacids and sixteen trace metal elements were measured in this study. The pH of fog water samples ranged from weakly acidic （pH 4.3） to weakly alkaline （pH 7.05） and the EC ranged from 32.4 to 436.3 μS/cm. The main cations in fog water were NH^4＋ and Ca2＋, accounting for 12.35% and 29.07% of those inorganic ions, respectively. In addition, SO24- and NO^-3 contributed to 25.52% and 12.93% to total anion concentrations respectively. Moreover, the dominant kinds of organicacids were formate and oxalate, occupying 45.28% and 28.03% of the total organicacids, respectively. For trace metal elements in fog samples, Al, Fe, Zn, and Ba revealed 34.6%, 16.4%, 19.3%, and 20.9% contributions to these sixteen trace element concentrations, respectively. The results indicated that pollutants were mainly from human activities, including fossil fuel combustion, biomass burning, steel-making, stone quarrying and sand digging. Besides, natural sources including natural background levels and long-range transport of sea salt particles also aggravated the pollution levels in the fog events along the Yangtze River.
基金financial support from the Natural Science Foundation of Liaoning Province (No. 2019-MS-046)。
文摘Pyrylium salts are a type of representative and convincing example of versatility and variety not only as a nodal point in organic transformations but also as an attractive building block in functional organic materials. Herein, we report an effective synthetic protocol to fabricate a new pyrylium-containing porous organic polymers(POPs), named TMP-P, via Knoevenagel condensation with 2,4,6-trimethylpyrylium salt(TMP) as the key building block and 1,4-phthalaldehyde as the linker. The resulting ionic polymer TMPP exhibited efficient visible-light-driven heterogeneous photodegradation of Rhodamine B, owing to the presence of wide visible light absorption and a narrow optical band gap triggered pyrylium core in the framework.
基金The Foundation of China Ocean Mineral Resources R&D Association under contract No.DY135-E2-4the Basic Scientific Fund for National Public Research Institutes of China under contract Nos 2018Q09,2018S02the National Natural Science Foundation of China under contract Nos 41706190,41876231。
文摘The waters near the Antarctic Peninsula have always been a study hot spot because of their variable and unique oceanographic conditions.To determine the distribution and possible influencing factors on phytoplankton size and abundance near the Antarctic Peninsula,a large-scale survey was conducted during the austral summer of2018.Samples were collected in 27 stations located in the Drake Passage(DP),South Shetland Islands(SSI),and South Orkney Islands(SOI).Phytoplankton communities were described using chlorophyll a(Chl a),flow cytometry and light microscopy to cover a size range from pico-to microphytoplankton.Nanophytoplankton,especially small nanophytoplankton(2-6μm)with abundance ranging from 0.66×10^(3) cells/mL to 8.46×10^(3) cells/mL,was predominant throughout the study area.Among different regions,there was an obvious size shift.The proportion of picophytoplankton near the Elephant Island(EI)and DP was higher than other regions,and larger cells were found mainly in east of SOI.The distribution of phytoplankton abundance detected by flow cytometry was not completely consistent with Chl a concentrations due to the contribution of larger cells to Chl a.Possible influencing factors on the phytoplankton size distribution were discussed.The properties of water masses such as temperature and salinity can influence the phytoplankton size distribution.Correlation analysis revealed that only picophytoplankton is significantly correlated with salinity.Light and Fe availability might affect phytoplankton abundance and size distribution especially near the waters of SSI and EI in this study.It was also speculated that the abundance of cryptophytes is possibly related to ice melting.
