Grain weight is one of the key components of wheat(Triticum aestivum L.)yield.Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(...Grain weight is one of the key components of wheat(Triticum aestivum L.)yield.Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(RIL)population derived from a cross between W7268 and Chuanyu 12(CY12)was employed to detect quantitative trait loci(QTLs)for thousand-grain weight(TGW),grain length(GL),grain width(GW),and the ratio of grain length to width(GLW)in six environments.Seven major QTLs,QGl.cib-2D,QGw.cib-2D,QGw.cib-3B,QGw.cib-4B.1,QGlw.cib-2D.1,QTgw.cib-2D.1 and QTgw.cib-3B.1,were consistently identified in at least four environments and the best linear unbiased estimation(BLUE)datasets,and they explained 2.61 to 34.85%of the phenotypic variance.Significant interactions were detected between the two major TGW QTLs and three major GW loci.In addition,QTgw.cib-3B.1 and QGw.cib-3B were co-located,and the improved TGW at this locus was contributed by GW.Unlike other loci,QTgw.cib-3B.1/QGw.cib-3B had no effect on grain number per spike(GNS).They were further validated in advanced lines using Kompetitive Allele Specific PCR(KASP)markers,and a comparison analysis indicated that QTgw.cib-3B.1/QGw.cib-3B is likely a novel locus.Six haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and cultivars.According to gene annotation,spatial expression patterns,ortholog analysis and sequence variation,the candidate gene of QTgw.cib-3B.1/QGw.cib-3B was predicted.Collectively,the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.展开更多
Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP...Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.展开更多
The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical perfo...The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical performance.Herein,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature selenization.The unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)Se.The density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron mobility.Significantly,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption energy.These findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.展开更多
To facilitate the coordinated and large-scale participation of residential flexible loads in demand response(DR),a load aggregator(LA)can integrate these loads for scheduling.In this study,a residential DR optimizatio...To facilitate the coordinated and large-scale participation of residential flexible loads in demand response(DR),a load aggregator(LA)can integrate these loads for scheduling.In this study,a residential DR optimization scheduling strategy was formulated considering the participation of flexible loads in DR.First,based on the operational characteristics of flexible loads such as electric vehicles,air conditioners,and dishwashers,their DR participation,the base to calculate the compensation price to users,was determined by considering these loads as virtual energy storage.It was quantified based on the state of virtual energy storage during each time slot.Second,flexible loads were clustered using the K-means algorithm,considering the typical operational and behavioral characteristics as the cluster centroid.Finally,the LA scheduling strategy was implemented by introducing a DR mechanism based on the directrix load.The simulation results demonstrate that the proposed DR approach can effectively reduce peak loads and fill valleys,thereby improving the load management performance.展开更多
Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical properties.In this study,the mechanical performance of GA under high-velocity projectil...Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical properties.In this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)simulations.The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading.Specifically,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene sheets.Moreover,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of temperatures.Finally,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile penetration.The research findings of this work demonstrate the significant potential of GA for energy absorption applications.展开更多
Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface a...Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template SiO2. 2-thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%. Comparing with pristine carbon, the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
In plants,WUSCHEL-related homeobox1(WOX1)homologs promote lamina mediolateral outgrowth.However,the downstream components linking WOX1 and lamina development remain unclear.In this study,we revealed the roles of WOX1 ...In plants,WUSCHEL-related homeobox1(WOX1)homologs promote lamina mediolateral outgrowth.However,the downstream components linking WOX1 and lamina development remain unclear.In this study,we revealed the roles of WOX1 in palmate leaf expansion in cucumber(Cucumis sativus).A cucumber mango fruit(mf)mutant,resulting from truncation of a WOX1-type protein(CsWOX1),displayed abnormal lamina growth and defects in the development of secondary and smaller veins.CsWOX1 was expressed in the middle mesophyll and leaf margins and rescued defects of the Arabidopsis wox1 prs double mutant.Transcriptomic analysis revealed that genes involved in auxin polar transport and auxin response were highly associated with leaf development.Analysis of the cucumber mf rl(round leaf)double mutant revealed that CsWOX1 functioned in vein development via PINOID(CsPID1)-controlled auxin transport.Overexpression of CsWOX1 in cucumber(CsWOX1-OE)affected vein patterning and produced‘butterfly-shaped’leaves.CsWOX1 physically interacted with CsTCP4a,which may account for the abnormal lamina development in the mf mutant line and the smaller leaves in the CsWOX1-OE plants.Our findings demonstrated that CsWOX1 regulates cucumber leaf vein development by modulating auxin polar transport;moreover,CsWOX1 regulates leaf size by controlling CIN-TCP genes.展开更多
As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activ...As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.展开更多
Objective: To investigate the clinical diagnostic value of peripheral lung cancer using multi-slice CT (MSCT) perfu- sion imaging and the relationship with microvessel density (MVD). Methods: 38 patients with pulmonar...Objective: To investigate the clinical diagnostic value of peripheral lung cancer using multi-slice CT (MSCT) perfu- sion imaging and the relationship with microvessel density (MVD). Methods: 38 patients with pulmonary masses proved by pathology including 25 cases of peripheral lung cancer and 13 cases of benign masses were studied prospectively with GE Lightspeed Qx/I plus 16-slice helical CT perfusion imaging, and 25 patients with lung cancer were comparative studied with its MVD calculated using LSAB. With the CT perfusion 2-body tumor software, the parameters of CT perfusion including blood value (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were analyzed. Results: The four param- eter values in lung cancer were all higher than that in pulmonary benign masses, and there were significant differences among BV, MTT and PS (P<0.05), especially in BV (P<0.01). The MVD value of lung cancer was higher than that of pulmonary benign masses (P<0.05), and the MVD of adenocarcinoma was higher than that of squamous cell carcinoma (P<0.05). In 25 cases with lung cancer, there was positive correlation only between BV and MVD value (r=0.852, P<0.01). Conclusion: It is helpful to diagnose the peripheral lung cancer with MSCT perfusion imaging and to differentiate from pulmonary benign masses, its bases are MVD pathologically.展开更多
As the cyber security has attracted great attention in recent years,and with all kinds of tools’(such as Network Agent,VPN and so on)help,traditional methods of tracking users like log analysis and cookie have been n...As the cyber security has attracted great attention in recent years,and with all kinds of tools’(such as Network Agent,VPN and so on)help,traditional methods of tracking users like log analysis and cookie have been not that effective.Especially for some privacy sensitive users who changed their browser configuration frequently to hide themselves.The Browser Fingerprinting technology proposed by Electronic Frontier Foundation(EFF)gives a new approach of tracking users,and then our team designed an enhanced fingerprint dealing solution based on browser fingerprinting technology.Our enhanced solution plays well in recognizing the similar fingerprints,but it is not that efficient.Nowadays we improve the algorithm and propose a high-performance,efficient Browser Fingerprint Recognition Model.Our new model reforms the fingerprint items set by EFF and propose a Fingerprint Tracking Algorithm(FTA)to deal with collected data.It can associate users with some browser configuration changes in different periods of time quickly and precisely.Through testing with the experimental website built on the public network,we prove the high-performance and efficiency of our algorithm with a 20%time-consuming decrease than ever.展开更多
In this paper,we give a systematic description of the 1st Wireless Communication Artificial Intelligence(AI)Competition(WAIC)which is hosted by IMT-2020(5G)Promotion Group 5G+AI Work Group.Firstly,the framework of ful...In this paper,we give a systematic description of the 1st Wireless Communication Artificial Intelligence(AI)Competition(WAIC)which is hosted by IMT-2020(5G)Promotion Group 5G+AI Work Group.Firstly,the framework of full channel state information(F-CSI)feedback problem and its corresponding channel dataset are provided.Then the enhancing schemes for DL-based F-CSI feedback including i)channel data analysis and preprocessing,ii)neural network design and iii)quantization enhancement are elaborated.The final competition results composed of different enhancing schemes are presented.Based on the valuable experience of 1stWAIC,we also list some challenges and potential study areas for the design of AI-based wireless communication systems.展开更多
Fruit shape and size are important appearance and yield traits in cucumber,but the underlying genes and their regulatory mechanisms remain poorly understood.Here we identified a mutant with spherical fruits from an Et...Fruit shape and size are important appearance and yield traits in cucumber,but the underlying genes and their regulatory mechanisms remain poorly understood.Here we identified a mutant with spherical fruits from an Ethyl Methane Sulfonate(EMS)-mutagenized library,named the qiu mutant.Compared with the cylindrical fruit shape in 32X(wild type),the fruit shape in qiu was round due to reduced fruit length and increased fruit diameter.MutMap analysis narrowed the candidate gene in the 6.47 MB range on Chr2,harboring the FS2.1 locus reported previously.A single-nucleotide polymorphism(SNP)(11359603)causing a truncated protein of CsaV3_2G013800,the homolog of tomato fruit shape gene SlTRM5,may underlie the fruit shape variation in the qiu mutant.Knockout of CsTRM5 by the CRISPR-Cas9 system confirmed that CsaV3_2G013800/CsTRM5 was the causal gene responsible for qiu.Sectioning analysis showed that the spherical fruit in qiu resulted mainly from increased and reduced cell division along the transverse and longitudinal directions,respectively.Meanwhile,the repressed cell expansion contributed to the decreased fruit length in qiu.Transcriptome profiling showed that the expression levels of cell-wall-related genes and abscisic acid(ABA)pathway genes were significantly upregulated in qiu.Hormone measurements indicated that ABA content was greatly increased in the qiu mutant.Exogenous ABA application reduced fruit elongation by inhibiting cell expansion in cucumber.Taken together,these data suggest that CsTRM5 regulates fruit shape by affecting cell division direction and cell expansion,and that ABA participates in the CsTRM5-mediated cell expansion during fruit elongation in cucumber.展开更多
Cucumber(Cucumis sativus L.)is an important vegetable crop species with great economic value.Shoot architecture determines the visual appearance of plants and has a strong impact on crop management and yield.Unlike mo...Cucumber(Cucumis sativus L.)is an important vegetable crop species with great economic value.Shoot architecture determines the visual appearance of plants and has a strong impact on crop management and yield.Unlike most model plant species,cucumber undergoes vegetative growth and reproductive growth simultaneously,in which leaves are produced from the shoot apical meristem and flowers are generated from leaf axils,during the majority of its life,a feature representative of the Cucurbitaceae family.Despite substantial advances achieved in understanding the regulation of plant form in Arabidopsis thaliana,rice,and maize,our understanding of the mechanisms controlling shoot architecture in Cucurbitaceae crop species is still limited.In this review,we focus on recent progress on elucidating the genetic regulatory pathways underlying the determinant/indeterminant growth habit,leaf shape,branch outgrowth,tendril identity,and vine length determination in cucumber.We also discuss the potential of applying biotechnology tools and resources for the generation of ideal plant types with desired architectural features to improve cucumber productivity and cultivation efficiency.展开更多
Recently,electrospinning(ESP)has been widely used as a synthetic technology to prepare nanofibers with unique properties from various raw materials.The applications of functionalized nanofibers have gradually develope...Recently,electrospinning(ESP)has been widely used as a synthetic technology to prepare nanofibers with unique properties from various raw materials.The applications of functionalized nanofibers have gradually developed into one of the most exciting topics in the field of materials science.In this review,we focus on the preparation of multi-structure fibrous nanomaterials by means of multi-fluidic ESP and review the applications of multi-structure nanofibers in energy,catalysis,and biology.First,the working principle and process of ESP are introduced;then,we demonstrate how the microfluidic concept is com-bined with the ESP technique to the multi-fluidic ESP technique.Subsequently,the applications of multi-structure nanofibers in energy(Li^(+)/Na^(+)batteries and Li–S batteries),hetero-catalysis,and biology(drug delivery and tissue engineering)are introduced.Finally,challenges and future directions in this emerging field are summarized.展开更多
Variable geometry truss manipulator (VGTM) has potential to work in the future space applications, of which a dynamic model is important to dynamic analysis and control of the system. In this paper, an approach is p...Variable geometry truss manipulator (VGTM) has potential to work in the future space applications, of which a dynamic model is important to dynamic analysis and control of the system. In this paper, an approach is presented to model the dynamic equations of a VGTM by independent variables, which consists of two double-octahedral truss units and a 3-revolute-prismatic-spherical (3-RPS) parallel manipulator. In this ap- proach, the kinematic recursive relations of two adjacent bodies and geometric constrains are used to deduce the kinematic equations of the VGTM, and Jourdain's velocity varia- tion principle is adopted to establish the dynamic equations of the system. The validity of the proposed dynamic model is verified by comparison of numerical simulations with the software ADAMS. Besides, an active controller for trajectory tracking of the system is designed by the computed torque method. The effectiveness of the controller is numer- ically proved.展开更多
Corolla opening is essential for the propagation of unisexual flowering plants,meanwhile commodity fruits with opening corolla have higher commodity value in cucumber fresh food market.Until now,there is little resear...Corolla opening is essential for the propagation of unisexual flowering plants,meanwhile commodity fruits with opening corolla have higher commodity value in cucumber fresh food market.Until now,there is little research on the mechanism of corolla opening in cucumber.In a previous paper,we identified a unique cucumber(Cucumis sativus)line(‘6457’)that possesses super ovaries and shows delayed corolla opening when nutrient supplies are abundant.We also previously showed that the expression of CsIPT1b(isopentenyl transferase)and CsUGT85A2(cytokinin glycosyltransferase)is correlated with the delayed opening of the female corolla.Here,we investigated the mechanism of delayed female corolla opening in cucumber by conducting transgenic experiments,hormone assays,and yeast one-hybrid assays.CsIPT1b and CsUGT85A2 positively and negatively regulated delayed female corolla opening,respectively.In CsIPT1b-overexpressing plants and CsUGT85A2 knockout plants,the content of the trans-zeatin riboside,trans-zeatin,and N6-isopentenyladenosine was increased.Overall,our findings indicate that CsIPT1b and CsUGT85A2 were important regulators of the timing of female corolla opening.These genes could thus be targets to cucumber molecular breeding of fruit with flowers remaining on the tip.展开更多
Objective: To test the expression of mutant p73, p53, ER and PR proteins in the esophageal normal mucosa, hyperplasia, dysplasia and squamous cell carcinoma, and research the clinically pathological significance and ...Objective: To test the expression of mutant p73, p53, ER and PR proteins in the esophageal normal mucosa, hyperplasia, dysplasia and squamous cell carcinoma, and research the clinically pathological significance and the correlation, for the early diagnosis, prognostic measure and therapy in clinic. Methods: With Immunohistochemistry, it was examined to show these tumor markers' expression in different epithelial lesions of 40 esophageal squamous cell carcinomas, 14 dysplasias, 14 hyperplasias and 14 normal mucosas. Results: The expression of p73 was 55%, 21%, 0% and 0% in the esophageal carcinoma, dysplasia, hyperplasia and normal mucosa, respectively. The significant difference in expression of p73 (P〈0.001) was observed between the esophageal normal mucosia, hyperplasia, dysplasia and esophageal squamous cell carcinoma with Fisher's exact test. Difference in expression of p73 (P〈0.05) was observed between the esophageal squamous cell carcinoma and dysplasia with X^2 test. The expression of p73 showed non-correlation with the patient's age, sex, tumor's grade, lymph-node metastasis and invasive depth (P〉0.05); Similarly, the expression of mutant p53 was 67.5%, 35.7%, 7% and 0%, respectively; In like manner, the expression of ER was 55%, 21.4%, 14.2% and 0%, respectively; The expression of PR was 57.5%,14.28%, 0% and 0%, respectively. The significant difference in expression of PR (P〈0.001) was observed with Fisher's exact test. Difference in expression of PR (P〈0.05) was observed between the esophageal squamous cell carcinoma and dysplasia with x2 test. The expression of PR (P〈0.05) was correlated with lymph-node metastasis, and showed non-correlation with the patient's age, sex, tumor's grade, and invasive depth (P〉0.05). Moreover, over-expression of mutant p53 and p73 showed significant correlation with ER and PR protein's positive expression (P〈0.05). Conclusion: P73 protein may become a new tumor's marker to diagnose esophageal squarnous celt carcinoma. Because the expression of p73 protein was closely correlated with ER and PR, they could be simultaneously examined to help to early diagnose, prognosticate and cure esophageal carcinoma.展开更多
Aims: The abnormal increase of bile acid is found in intrahepatic cholestasis of pregnancy (ICP). It also can be observed the damage of placental tissue in ICP. The aim of this study was to find the associations of th...Aims: The abnormal increase of bile acid is found in intrahepatic cholestasis of pregnancy (ICP). It also can be observed the damage of placental tissue in ICP. The aim of this study was to find the associations of the bile acid in umbilical vein and the damage of placental tissue. Methods: Thirty women diagnosed with ICP and fifty normal pregnant women between September 2015 and September 2017 at Nanshan District Maternity & Child Healthcare Hospital of Shenzhen were included in this study. The glycocholic acid (GA), total bile acids (TBA), total bilirubin (TB), direct bilirubin (DB) and albumin level in umbilical vein were measured by cycle enzyme method in ICP and control group. The placental damage was analyzed by morphologic study using hematoxylin dyes in two groups. The correlation between the level of the bile acid in the umbilical vein and the damage of the placenta was assessed using SPSS software. Results: The GA, TBA, TB, DB and albumin level in umbilical vein were significantly higher in ICP than those of pregnant women, respectively. The placental villis were expanded and the structure was destroyed in ICP. The vessel was damaged and the cell trophoblast hyperplasia in ICP. It also can be seen that there was obvious nodules and a typical fibrous necrotic substance in ICP but not in control group. There is a positive correlation between the level of the TBA in the umbilical vein and the damage of the placenta in ICP. Conclusion: The TBAs were significantly higher in umbilical vein and were related to the placental damage in ICP.展开更多
The reconstruction of sea surface temperature(SST) is a key issue in research on paleoceanography. The recently related studies are mainly concentrated on the Quaternary. The skeletons of a typical species of benthoni...The reconstruction of sea surface temperature(SST) is a key issue in research on paleoceanography. The recently related studies are mainly concentrated on the Quaternary. The skeletons of a typical species of benthonic foraminifer(Amphistegina radiata) in the top 0–375.30 m interval of Well "Xike-1" reef core, Shidao Island, the Xisha Islands, are uniformly selected. The ratios of magnesium to calcium concentrations and other indicators are analyzed by an electron microprobe analysis(EMPA) with the purpose of estimating the paleo-SSTs since the Pliocene and further investigating the periodic change law of paleoclimate in the South China Sea(SCS).Meanwhile, the geologic significance of paleoclimatic events in the SCS is discussed with global perspectives. The results indicate that the paleo-SSTs reconstructed by the ratios of magnesium to calcium concentrations in the SCS show a general periodic trend of "high–low–high–low" in values changes since the Pliocene. By comparison,the fluctuations of reconstructed paleo-SSTs are much stronger in the Quaternary. Moreover, the variations of the ratios of magnesium to calcium concentrations in the A. radiata skeletons have recorded a series of major paleoclimatic events since the Pliocene, of which the Quaternary glaciation events and the Arctic ice cap forming events during the late Pliocene are more significant. Thus, using the changes of the ratios of magnesium to calcium concentrations in the A. radiata skeletons from Well "Xike-1" reef core to reflect the relative changes of paleo-SSTs is a relatively feasible and reliable way in the SCS, which is also proved by the correlation of drilling cores characteristics in this area.展开更多
基金supported by the Major Program of National Agricultural Science and Technology of China(NK20220607)the West Light Foundation of the Chinese Academy of Sciences(2022XBZG_XBQNXZ_A_001)the Sichuan Science and Technology Program,China(2022ZDZX0014)。
文摘Grain weight is one of the key components of wheat(Triticum aestivum L.)yield.Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(RIL)population derived from a cross between W7268 and Chuanyu 12(CY12)was employed to detect quantitative trait loci(QTLs)for thousand-grain weight(TGW),grain length(GL),grain width(GW),and the ratio of grain length to width(GLW)in six environments.Seven major QTLs,QGl.cib-2D,QGw.cib-2D,QGw.cib-3B,QGw.cib-4B.1,QGlw.cib-2D.1,QTgw.cib-2D.1 and QTgw.cib-3B.1,were consistently identified in at least four environments and the best linear unbiased estimation(BLUE)datasets,and they explained 2.61 to 34.85%of the phenotypic variance.Significant interactions were detected between the two major TGW QTLs and three major GW loci.In addition,QTgw.cib-3B.1 and QGw.cib-3B were co-located,and the improved TGW at this locus was contributed by GW.Unlike other loci,QTgw.cib-3B.1/QGw.cib-3B had no effect on grain number per spike(GNS).They were further validated in advanced lines using Kompetitive Allele Specific PCR(KASP)markers,and a comparison analysis indicated that QTgw.cib-3B.1/QGw.cib-3B is likely a novel locus.Six haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and cultivars.According to gene annotation,spatial expression patterns,ortholog analysis and sequence variation,the candidate gene of QTgw.cib-3B.1/QGw.cib-3B was predicted.Collectively,the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.
基金supported by the Scientific and Innovative Action Plan of Shanghai(21N31900800)Shanghai Rising-Star Program(23QB1403500)+4 种基金the Shanghai Sailing Program(20YF1443000)Shanghai Science and Technology Commission,the Belt and Road Project(20310750500)Talent Project of SAAS(2023-2025)Runup Plan of SAAS(ZP22211)the SAAS Program for Excellent Research Team(2022(B-16))。
文摘Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.
基金The Natural Science Foundation of Henan Province(222300420083)the Opening Foundation of State Key Laboratory of Chemistry and Utilization of Carbon-based Energy Resource of Xinjiang University(KFKT2021004)。
文摘The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical performance.Herein,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature selenization.The unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)Se.The density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron mobility.Significantly,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption energy.These findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.
基金supported by the Basic Science(Natural Science)Research Project of Jiangsu Higher Education Institutions(No.23KJB470020)the Natural Science Foundation of Jiangsu Province(Youth Fund)(No.BK20230384)。
文摘To facilitate the coordinated and large-scale participation of residential flexible loads in demand response(DR),a load aggregator(LA)can integrate these loads for scheduling.In this study,a residential DR optimization scheduling strategy was formulated considering the participation of flexible loads in DR.First,based on the operational characteristics of flexible loads such as electric vehicles,air conditioners,and dishwashers,their DR participation,the base to calculate the compensation price to users,was determined by considering these loads as virtual energy storage.It was quantified based on the state of virtual energy storage during each time slot.Second,flexible loads were clustered using the K-means algorithm,considering the typical operational and behavioral characteristics as the cluster centroid.Finally,the LA scheduling strategy was implemented by introducing a DR mechanism based on the directrix load.The simulation results demonstrate that the proposed DR approach can effectively reduce peak loads and fill valleys,thereby improving the load management performance.
基金supported by the National Natural Science Foundation of China(No.12102256).
文摘Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical properties.In this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)simulations.The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading.Specifically,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene sheets.Moreover,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of temperatures.Finally,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile penetration.The research findings of this work demonstrate the significant potential of GA for energy absorption applications.
基金supported by the University of Electronic Science and Technology of China(Y02002010301080)the National Science Foundation of China(51502032)the financial support from Natural Science Foundation of Zhejiang Province(No.LQ14E020003)
文摘Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template SiO2. 2-thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%. Comparing with pristine carbon, the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金supported by the National Key Research and Development Program of China(2019YFD1000300)the National Natural Science Foundation of China(Nos.31672150 and 31872111).
文摘In plants,WUSCHEL-related homeobox1(WOX1)homologs promote lamina mediolateral outgrowth.However,the downstream components linking WOX1 and lamina development remain unclear.In this study,we revealed the roles of WOX1 in palmate leaf expansion in cucumber(Cucumis sativus).A cucumber mango fruit(mf)mutant,resulting from truncation of a WOX1-type protein(CsWOX1),displayed abnormal lamina growth and defects in the development of secondary and smaller veins.CsWOX1 was expressed in the middle mesophyll and leaf margins and rescued defects of the Arabidopsis wox1 prs double mutant.Transcriptomic analysis revealed that genes involved in auxin polar transport and auxin response were highly associated with leaf development.Analysis of the cucumber mf rl(round leaf)double mutant revealed that CsWOX1 functioned in vein development via PINOID(CsPID1)-controlled auxin transport.Overexpression of CsWOX1 in cucumber(CsWOX1-OE)affected vein patterning and produced‘butterfly-shaped’leaves.CsWOX1 physically interacted with CsTCP4a,which may account for the abnormal lamina development in the mf mutant line and the smaller leaves in the CsWOX1-OE plants.Our findings demonstrated that CsWOX1 regulates cucumber leaf vein development by modulating auxin polar transport;moreover,CsWOX1 regulates leaf size by controlling CIN-TCP genes.
基金supported by the National Natural Science Foundation of China(Grant No.21701144)。
文摘As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.
基金Supported by a grant from the Scientific Research Foundation of the Educational Department of Liaoning province (No. 20272277).
文摘Objective: To investigate the clinical diagnostic value of peripheral lung cancer using multi-slice CT (MSCT) perfu- sion imaging and the relationship with microvessel density (MVD). Methods: 38 patients with pulmonary masses proved by pathology including 25 cases of peripheral lung cancer and 13 cases of benign masses were studied prospectively with GE Lightspeed Qx/I plus 16-slice helical CT perfusion imaging, and 25 patients with lung cancer were comparative studied with its MVD calculated using LSAB. With the CT perfusion 2-body tumor software, the parameters of CT perfusion including blood value (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were analyzed. Results: The four param- eter values in lung cancer were all higher than that in pulmonary benign masses, and there were significant differences among BV, MTT and PS (P<0.05), especially in BV (P<0.01). The MVD value of lung cancer was higher than that of pulmonary benign masses (P<0.05), and the MVD of adenocarcinoma was higher than that of squamous cell carcinoma (P<0.05). In 25 cases with lung cancer, there was positive correlation only between BV and MVD value (r=0.852, P<0.01). Conclusion: It is helpful to diagnose the peripheral lung cancer with MSCT perfusion imaging and to differentiate from pulmonary benign masses, its bases are MVD pathologically.
基金supported by the Beijing Municipal Natural Science Foundation(No.4172006)Humanity and Social Science Youth foundation of Ministry of Education of China under Grant No. 13YJCZH065+2 种基金General Program of Science and Technology Development Project of Beijing Municipal Education Commission of China under Grant No. km201410005012Open Research Fund of Beijing Key Laboratory of Trusted ComputingOpen Research Fund of Key Laboratory of Trustworthy Distributed Computing and Service (BUPT), Ministry of Education..
文摘As the cyber security has attracted great attention in recent years,and with all kinds of tools’(such as Network Agent,VPN and so on)help,traditional methods of tracking users like log analysis and cookie have been not that effective.Especially for some privacy sensitive users who changed their browser configuration frequently to hide themselves.The Browser Fingerprinting technology proposed by Electronic Frontier Foundation(EFF)gives a new approach of tracking users,and then our team designed an enhanced fingerprint dealing solution based on browser fingerprinting technology.Our enhanced solution plays well in recognizing the similar fingerprints,but it is not that efficient.Nowadays we improve the algorithm and propose a high-performance,efficient Browser Fingerprint Recognition Model.Our new model reforms the fingerprint items set by EFF and propose a Fingerprint Tracking Algorithm(FTA)to deal with collected data.It can associate users with some browser configuration changes in different periods of time quickly and precisely.Through testing with the experimental website built on the public network,we prove the high-performance and efficiency of our algorithm with a 20%time-consuming decrease than ever.
文摘In this paper,we give a systematic description of the 1st Wireless Communication Artificial Intelligence(AI)Competition(WAIC)which is hosted by IMT-2020(5G)Promotion Group 5G+AI Work Group.Firstly,the framework of full channel state information(F-CSI)feedback problem and its corresponding channel dataset are provided.Then the enhancing schemes for DL-based F-CSI feedback including i)channel data analysis and preprocessing,ii)neural network design and iii)quantization enhancement are elaborated.The final competition results composed of different enhancing schemes are presented.Based on the valuable experience of 1stWAIC,we also list some challenges and potential study areas for the design of AI-based wireless communication systems.
基金supported by the National Natural Science Foundation of China(31772327 and 32025033)the Key R&D Program of Hebei Province(21326309D)+1 种基金the Scientific Research Foundation of Hebei Normal University of Science and Technology(2019YB015 and 2020JK004)the Natural Science Foundation of Hebei Province(C2020407015).
文摘Fruit shape and size are important appearance and yield traits in cucumber,but the underlying genes and their regulatory mechanisms remain poorly understood.Here we identified a mutant with spherical fruits from an Ethyl Methane Sulfonate(EMS)-mutagenized library,named the qiu mutant.Compared with the cylindrical fruit shape in 32X(wild type),the fruit shape in qiu was round due to reduced fruit length and increased fruit diameter.MutMap analysis narrowed the candidate gene in the 6.47 MB range on Chr2,harboring the FS2.1 locus reported previously.A single-nucleotide polymorphism(SNP)(11359603)causing a truncated protein of CsaV3_2G013800,the homolog of tomato fruit shape gene SlTRM5,may underlie the fruit shape variation in the qiu mutant.Knockout of CsTRM5 by the CRISPR-Cas9 system confirmed that CsaV3_2G013800/CsTRM5 was the causal gene responsible for qiu.Sectioning analysis showed that the spherical fruit in qiu resulted mainly from increased and reduced cell division along the transverse and longitudinal directions,respectively.Meanwhile,the repressed cell expansion contributed to the decreased fruit length in qiu.Transcriptome profiling showed that the expression levels of cell-wall-related genes and abscisic acid(ABA)pathway genes were significantly upregulated in qiu.Hormone measurements indicated that ABA content was greatly increased in the qiu mutant.Exogenous ABA application reduced fruit elongation by inhibiting cell expansion in cucumber.Taken together,these data suggest that CsTRM5 regulates fruit shape by affecting cell division direction and cell expansion,and that ABA participates in the CsTRM5-mediated cell expansion during fruit elongation in cucumber.
基金This work is supported by grants from the National Natural Science Foundation of China(32025033 and 31930097)the National Key Research and Development Program(2018YFD1000800).
文摘Cucumber(Cucumis sativus L.)is an important vegetable crop species with great economic value.Shoot architecture determines the visual appearance of plants and has a strong impact on crop management and yield.Unlike most model plant species,cucumber undergoes vegetative growth and reproductive growth simultaneously,in which leaves are produced from the shoot apical meristem and flowers are generated from leaf axils,during the majority of its life,a feature representative of the Cucurbitaceae family.Despite substantial advances achieved in understanding the regulation of plant form in Arabidopsis thaliana,rice,and maize,our understanding of the mechanisms controlling shoot architecture in Cucurbitaceae crop species is still limited.In this review,we focus on recent progress on elucidating the genetic regulatory pathways underlying the determinant/indeterminant growth habit,leaf shape,branch outgrowth,tendril identity,and vine length determination in cucumber.We also discuss the potential of applying biotechnology tools and resources for the generation of ideal plant types with desired architectural features to improve cucumber productivity and cultivation efficiency.
基金the National Natural Science Foundation of China (22175007, 21975007, 21774005, and21433012)the National Natural Science Foundation for Outstanding Youth Foundation+4 种基金the Fundamental Research Funds for the Central Universitiesthe National Program for Support of Top-Notch Young Professionalsthe 111 project (B14009)the National Postdoctoral Program for Innovative Talents (BX20190027)the China Postdoctoral Science Foundation Funded Project (2019M650431)
文摘Recently,electrospinning(ESP)has been widely used as a synthetic technology to prepare nanofibers with unique properties from various raw materials.The applications of functionalized nanofibers have gradually developed into one of the most exciting topics in the field of materials science.In this review,we focus on the preparation of multi-structure fibrous nanomaterials by means of multi-fluidic ESP and review the applications of multi-structure nanofibers in energy,catalysis,and biology.First,the working principle and process of ESP are introduced;then,we demonstrate how the microfluidic concept is com-bined with the ESP technique to the multi-fluidic ESP technique.Subsequently,the applications of multi-structure nanofibers in energy(Li^(+)/Na^(+)batteries and Li–S batteries),hetero-catalysis,and biology(drug delivery and tissue engineering)are introduced.Finally,challenges and future directions in this emerging field are summarized.
基金Project supported by the National Natural Science Foundation of China(Nos.11132001,11272202,and 11472171)the Key Scientific Project of Shanghai Municipal Education Commission(No.14ZZ021)the Natural Science Foundation of Shanghai(No.14ZR1421000)
文摘Variable geometry truss manipulator (VGTM) has potential to work in the future space applications, of which a dynamic model is important to dynamic analysis and control of the system. In this paper, an approach is presented to model the dynamic equations of a VGTM by independent variables, which consists of two double-octahedral truss units and a 3-revolute-prismatic-spherical (3-RPS) parallel manipulator. In this ap- proach, the kinematic recursive relations of two adjacent bodies and geometric constrains are used to deduce the kinematic equations of the VGTM, and Jourdain's velocity varia- tion principle is adopted to establish the dynamic equations of the system. The validity of the proposed dynamic model is verified by comparison of numerical simulations with the software ADAMS. Besides, an active controller for trajectory tracking of the system is designed by the computed torque method. The effectiveness of the controller is numer- ically proved.
基金supported by the National Natural Science Foundation of China(Grant No.31772327)S&T Program of Hebei(Grant No.21326309D).
文摘Corolla opening is essential for the propagation of unisexual flowering plants,meanwhile commodity fruits with opening corolla have higher commodity value in cucumber fresh food market.Until now,there is little research on the mechanism of corolla opening in cucumber.In a previous paper,we identified a unique cucumber(Cucumis sativus)line(‘6457’)that possesses super ovaries and shows delayed corolla opening when nutrient supplies are abundant.We also previously showed that the expression of CsIPT1b(isopentenyl transferase)and CsUGT85A2(cytokinin glycosyltransferase)is correlated with the delayed opening of the female corolla.Here,we investigated the mechanism of delayed female corolla opening in cucumber by conducting transgenic experiments,hormone assays,and yeast one-hybrid assays.CsIPT1b and CsUGT85A2 positively and negatively regulated delayed female corolla opening,respectively.In CsIPT1b-overexpressing plants and CsUGT85A2 knockout plants,the content of the trans-zeatin riboside,trans-zeatin,and N6-isopentenyladenosine was increased.Overall,our findings indicate that CsIPT1b and CsUGT85A2 were important regulators of the timing of female corolla opening.These genes could thus be targets to cucumber molecular breeding of fruit with flowers remaining on the tip.
文摘Objective: To test the expression of mutant p73, p53, ER and PR proteins in the esophageal normal mucosa, hyperplasia, dysplasia and squamous cell carcinoma, and research the clinically pathological significance and the correlation, for the early diagnosis, prognostic measure and therapy in clinic. Methods: With Immunohistochemistry, it was examined to show these tumor markers' expression in different epithelial lesions of 40 esophageal squamous cell carcinomas, 14 dysplasias, 14 hyperplasias and 14 normal mucosas. Results: The expression of p73 was 55%, 21%, 0% and 0% in the esophageal carcinoma, dysplasia, hyperplasia and normal mucosa, respectively. The significant difference in expression of p73 (P〈0.001) was observed between the esophageal normal mucosia, hyperplasia, dysplasia and esophageal squamous cell carcinoma with Fisher's exact test. Difference in expression of p73 (P〈0.05) was observed between the esophageal squamous cell carcinoma and dysplasia with X^2 test. The expression of p73 showed non-correlation with the patient's age, sex, tumor's grade, lymph-node metastasis and invasive depth (P〉0.05); Similarly, the expression of mutant p53 was 67.5%, 35.7%, 7% and 0%, respectively; In like manner, the expression of ER was 55%, 21.4%, 14.2% and 0%, respectively; The expression of PR was 57.5%,14.28%, 0% and 0%, respectively. The significant difference in expression of PR (P〈0.001) was observed with Fisher's exact test. Difference in expression of PR (P〈0.05) was observed between the esophageal squamous cell carcinoma and dysplasia with x2 test. The expression of PR (P〈0.05) was correlated with lymph-node metastasis, and showed non-correlation with the patient's age, sex, tumor's grade, and invasive depth (P〉0.05). Moreover, over-expression of mutant p53 and p73 showed significant correlation with ER and PR protein's positive expression (P〈0.05). Conclusion: P73 protein may become a new tumor's marker to diagnose esophageal squarnous celt carcinoma. Because the expression of p73 protein was closely correlated with ER and PR, they could be simultaneously examined to help to early diagnose, prognosticate and cure esophageal carcinoma.
文摘Aims: The abnormal increase of bile acid is found in intrahepatic cholestasis of pregnancy (ICP). It also can be observed the damage of placental tissue in ICP. The aim of this study was to find the associations of the bile acid in umbilical vein and the damage of placental tissue. Methods: Thirty women diagnosed with ICP and fifty normal pregnant women between September 2015 and September 2017 at Nanshan District Maternity & Child Healthcare Hospital of Shenzhen were included in this study. The glycocholic acid (GA), total bile acids (TBA), total bilirubin (TB), direct bilirubin (DB) and albumin level in umbilical vein were measured by cycle enzyme method in ICP and control group. The placental damage was analyzed by morphologic study using hematoxylin dyes in two groups. The correlation between the level of the bile acid in the umbilical vein and the damage of the placenta was assessed using SPSS software. Results: The GA, TBA, TB, DB and albumin level in umbilical vein were significantly higher in ICP than those of pregnant women, respectively. The placental villis were expanded and the structure was destroyed in ICP. The vessel was damaged and the cell trophoblast hyperplasia in ICP. It also can be seen that there was obvious nodules and a typical fibrous necrotic substance in ICP but not in control group. There is a positive correlation between the level of the TBA in the umbilical vein and the damage of the placenta in ICP. Conclusion: The TBAs were significantly higher in umbilical vein and were related to the placental damage in ICP.
基金The National Science and Technology Major Project of China under contract No.2011ZX05025-002-03the Project of China National Offshore Oil Corporation(CNOOC)Limited under contract No.CCL2013ZJFNO729the National Natural Science Foundation of China under contract No.41530963
文摘The reconstruction of sea surface temperature(SST) is a key issue in research on paleoceanography. The recently related studies are mainly concentrated on the Quaternary. The skeletons of a typical species of benthonic foraminifer(Amphistegina radiata) in the top 0–375.30 m interval of Well "Xike-1" reef core, Shidao Island, the Xisha Islands, are uniformly selected. The ratios of magnesium to calcium concentrations and other indicators are analyzed by an electron microprobe analysis(EMPA) with the purpose of estimating the paleo-SSTs since the Pliocene and further investigating the periodic change law of paleoclimate in the South China Sea(SCS).Meanwhile, the geologic significance of paleoclimatic events in the SCS is discussed with global perspectives. The results indicate that the paleo-SSTs reconstructed by the ratios of magnesium to calcium concentrations in the SCS show a general periodic trend of "high–low–high–low" in values changes since the Pliocene. By comparison,the fluctuations of reconstructed paleo-SSTs are much stronger in the Quaternary. Moreover, the variations of the ratios of magnesium to calcium concentrations in the A. radiata skeletons have recorded a series of major paleoclimatic events since the Pliocene, of which the Quaternary glaciation events and the Arctic ice cap forming events during the late Pliocene are more significant. Thus, using the changes of the ratios of magnesium to calcium concentrations in the A. radiata skeletons from Well "Xike-1" reef core to reflect the relative changes of paleo-SSTs is a relatively feasible and reliable way in the SCS, which is also proved by the correlation of drilling cores characteristics in this area.