This exploratory study examines whether genre has an impact on syntactic complexity and holistic rating in EFL writing. Over 300 sample texts produced by intermediate learners were collected from a test and some regul...This exploratory study examines whether genre has an impact on syntactic complexity and holistic rating in EFL writing. Over 300 sample texts produced by intermediate learners were collected from a test and some regular after-class assignments for English writing courses. Each participant completed two writing tasks, one argumentative and the other narrative. Results show that genre type has a significant impact on L2 syntactic complexity. Genre effect is found stronger with timed writing tasks. L2 holistic ratings show correlation with syntactic complexity on the different measure(s) depending on genre type and planning conditions. Regression analyses reveal that for timed writing tasks, clausal density(clauses per sentence) is a reliable predictor for holistic assessment on intermediate EFL learners’ writing quality. It is found to account for 6% of the score variance for timed writing and 10% for timed argumentative writing. Genre is evidenced to be related to EFL writing holistic ratings. Closer examination indicates that while syntactic complexity is predictive of holistic writing scores for argumentative writing, it does not correlate with holistic scores for narrative writing. Other linguistic features rather than syntactic complexity may be accountable. Overall, the study lends support to genre effect in the relationship between syntactic complexity and L2 writing quality holistic rating.展开更多
Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali serie...Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali series. Petrology and geochemistry data indicate that the volcanic rocks may be formed in a continental rift environment. The volcanic rocks are in conformable contact with the overlying and underlying wall rocks, with such typical sedimentary structures as laminated and striped ones, and the host rocks of the volcanic rocks contain lots of marine fossils such as tentaculite. Many pieces of evidence indicate that the eruption environment of the volcanic rocks is a sea-facies one. The volcanic rocks are of the LREE-enrichment type, with high ratios of light rare-earth elements to heavy rare-earth elements. In addition, they display moderately negative δEu anomalies and moderately negative δCe anomalies with a higher degree of LREE and HREE fractionation. Through the Q-cluster analysis of the REE samples, it is indicated that the ores have a closer relation with the layered volcanic rocks, and also possess a certain inheritance-consistency relationship with the layered volcanic rocks. The source of ore-forming materials may be related with volcanism. It is proposed that the ore deposit in the study area should be genetically explained as the result of marine volcano-sedimentary exhalation of hot water and late superposition-reworking.展开更多
A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/s...A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account.展开更多
AIM: To quantitatively analyze the retinal intermediate and deep capillary plexus(ICP and DCP) in patients with retinal deep vascular complex ischemia(RDVCI), using 3D projection artifacts removal(3D PAR) optical cohe...AIM: To quantitatively analyze the retinal intermediate and deep capillary plexus(ICP and DCP) in patients with retinal deep vascular complex ischemia(RDVCI), using 3D projection artifacts removal(3D PAR) optical coherence tomography angiography(OCTA).METHODS: RDVCI patients and gender-and agematched healthy controls were assessed and underwent OCTA examinations. The parafoveal vessel density(PFVD) of retinal deep vascular complex(DVC), ICP, and DCP were analyzed, and the percentage of reduction(PR) of PFVD was calculated.RESULTS: Twenty-four eyes in 22 RDVCI patients(20 in acute phase and 4 in chronic phase) and 24 eyes of 22 healthy subjects were enrolled as the control group. Significant reduction of PFVD in DVC, ICP, and DCP was observed in comparison with the controls(DVC: acute: 43.59%±6.58% vs 49.92%±5.49%, PR=12.69%;chronic: 43.50%±3.33% vs 51.20%±3.80%, PR=15.04%. ICP: acute: 40.28%±7.91% vs 46.97%±7.14%, PR=14.23%;chronic: 41.48%±2.87% vs 46.43%±3.29%, PR=10.66%. DCP: acute: 45.44%±8.27% vs 51.51%±9.97%, PR=11.79%;chronic: 37.78%±3.48% vs 51.73%±5.17%, PR=26.97%;all P<0.05). No significant PR difference was found among DVC, ICP, and DCP of RDVCI in acute phase(P=0.812), but significant difference in chronic phase(P=0.006, DVC vs DCP, ICP vs DCP). No significant difference in PR between acute and chronic phases in the DVC(P=0.735) or ICP(P=0.681) was found, but significant difference in the DCP(P=0.041).CONCLUSION: The PFVD of DVC, ICP, and DCP in RDVCI is significantly decreased in both acute and chronic phases. ICP impairment is stabilized from acute to chronic phase in RDVCI, whereas subsequent DCP impairment is uncovered and can be explained by ischemia-reperfusion damage.展开更多
The‘human-land relationship’has long been a central topic in geography,ecology,and social sciences.And dynamic monit-oring of the land use/cover change(LUCC)and landscape pattern studies of land use provide essentia...The‘human-land relationship’has long been a central topic in geography,ecology,and social sciences.And dynamic monit-oring of the land use/cover change(LUCC)and landscape pattern studies of land use provide essential theoretical support for this field.On the basis of physicogeographical regionalization and landscape ecology theory,this study proposed a method for characterizing land-scape pattern by using the minmium natural complex as the basic evaluation unit,constructing a four-level classification framework that included natural area,landscape region,landscape subregion,and landscape group.The method was tested in the Songhua River Basin,China,and the results revealed that:(1)the landscape pattern characterization in the Songhua River Basin validated the feasibility of the proposed method,and the use of the minimum natural complex as the basic measurement unit for landscape pattern characterization be-nefited research in this field.(2)The multiscale landscape pattern characterization system,which was framed around natural area,land-scape region,landscape subregion,and landscape group,accurately reflected the spatial heterogeneity of the physical geographic envir-onment and the impact of human activities on the landscape pattern in the Songhua River Basin.The nature-dominated landscape region was mainly concentrated in high-altitude mountainous and hilly areas,the human-dominated landscape region was located on plains and platforms,and the human-land interaction landscape region exhibited a landscape pattern that is closely related to natural factors such as temperature,precipitation,and soil.(3)The proposed method not only revealed the complex interactions between the physical geograph-ic environment and human activities but also provided scientific support for land use planning and ecological environment management.Future research should incorporate higher-resolution data and socioeconomic factors to further explore the dynamic changes in land-scape patterns and their impacts on the regional ecological environment.展开更多
The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of...The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of complex system are also given in this paper. Otherwise, the qualitative description of complex system is presented at first. On the basis of analyzing the existing brittleness problems, linguistic description and mathematic description of brittleness are given as well. Three kinds of phenomena to judge brittleness of complex system are also given, based on catastrophe theory. Basic characteristics of brittleness are given on the basis of its mathematic description. Two critical point sets are defined by using catastrophe theory. The definition of brittleness and its related theory can serve the control of complex system, and provide theoretical basis for the design and control of complex system.展开更多
Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica...Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica)has multiple functions,modulating both anthocyanin biosynthesis and cell acidification.Here,we show that MdbHLH3 also regulates ethylene biosynthesis and leaf senescence by promoting the expression of dehydratase-enolasephosphatase complex 1(MdDEP1).Therefore,we propose a model whereby MdbHLH3 acts as a crucial factor that modulates anthocyanin biosynthesis and cell acidification in addition to fruit ripening and leaf senescence by regulating distinct target genes.展开更多
The Assam-Meghalaya Gneissic Complex(AMGC)of northeast India contains numerous Pan-African granitic bodies that have been attributed to post-collisional rift-related magmatism.The present study is concerned with the f...The Assam-Meghalaya Gneissic Complex(AMGC)of northeast India contains numerous Pan-African granitic bodies that have been attributed to post-collisional rift-related magmatism.The present study is concerned with the first appraisal of intermediate magmatism(diorite,monzonite,and monzodiorite)found in the Borjuri Pluton of Mikir Massif,which is the eastern extension of AMGC.The diorites are strongly metaluminous and exhibit enriched LREE([La/Yb]N=1.63–7.37)with respect to HREE([Gd/Yb]N=1.95–2.27).The studied rocks do not show any mineralogical or textural indication of metamorphism.Tectonic discrimination diagrams indicate that these rocks originated in a within-plate tectonic setting.The lower Mg#(33.49–38.69),low Cr(below detection limit),and Ni(27–41 ppm)contents along with elemental ratios such as Rb/Sr(0.32–0.95),La/Nb(0.49–4.21),and Nb/Ce(0.11–0.64)suggest a crustal source for the diorites.Discrimination diagrams coupled with elemental ratios suggest that these rocks originated due to partial melting of mafic components in the crust with possible contribution from mantle materials.The P–T conditions of diorite emplacement(7.4 kbar,688℃)were calculated using the amphibole-plagioclase geothermobarometer.Geochemical and geochronological data of the Pan-African felsic plutons reported from the AMGC indicate that these rocks were emplaced in a post-collisional extensional regime.The Borjuri Pluton is in close proximity with the Kathalguri Pluton,which has been reported as a product of PanAfrican magmatism.In view of the numerous extensional Pan-African felsic magmatism reported from the AMGC and based on the close vicinity of the Borjuri diorites with the Kathalguri granites,we speculate that the Borjuri diorites are products of the Pan-African post-collisional magmatism.展开更多
Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+...Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+, FeO and MgO values are relatively high and the T, M3+, Fe2O3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2+ values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2+ and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2O3 and SiO2 in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure.展开更多
In this paper,a sexually transmitted disease model is proposed on complex networks,where contacts between humans are treated as a scale-free social network.There are three groups in our model,which are dangerous male,...In this paper,a sexually transmitted disease model is proposed on complex networks,where contacts between humans are treated as a scale-free social network.There are three groups in our model,which are dangerous male,non-dangerous male,and female.By mathematical analysis,we obtain the basic reproduction number for the existence of endemic equilibrium and study the effects of various immunization schemes about different groups.Furthermore,numerical simulations are undertaken to verify more conclusions.展开更多
In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image proc...In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.展开更多
Based on the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni（Ⅱ）-NH3-CO2-3-H2O system at ambient temperature were deduced theoretically and the thermody...Based on the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni（Ⅱ）-NH3-CO2-3-H2O system at ambient temperature were deduced theoretically and the thermodynamic diagrams of lg[Ni]T versus pH at different solution compositions were drawn, which was quite effective to explain the formation mechanism of precipitation particles with different microscopic shapes. When pH of the solution is below （7.0,） free nickel ions are dominant and when the precipitant is added, the fast coagulation will take place leading to the loose flocculation particles. While pH is above 7.0, because of the coordination of nickel ion with ammonia, the precipitation proceeds slowly accompanying with the release of Ni2+ from the multi-coordinated Ni（NH3）2+n（n=1, 2, …, 6）, which easily leads to the formation of the dense spherical particles.展开更多
The complexation of Cr^3＋ with F^- undergoes a muhistep reversible process. An approach to research the involved equilibria and kinetics using suitable chemometrics methods to the online measured UV-Vis spectra is pr...The complexation of Cr^3＋ with F^- undergoes a muhistep reversible process. An approach to research the involved equilibria and kinetics using suitable chemometrics methods to the online measured UV-Vis spectra is proposed. By investigating the equilibrium spectra of the complexes at different molar ratios of M to L（ metal to ligand） and 50 ℃, the result of Principal Component Analysis（PCA） shows that three complexes, ML, ML2 and ML3, can be formed under the research conditions. The spectrum of each complex was then analyzed and the accumulated equilibrium constants were calculated by applying Target Testing Factor Analysis（TITA）. Meanwhile, a reactive intermediate was observed before the formation of MLx during the specific kinetic study at 15℃. The equilibrium constant and spectrum of the intermediate as well as the rate constants were all resolved by using TTFA.展开更多
A numerical investigation of thin-walled complex section steel columns with intermediate stiffeners was performed using finite element analysis. An accurate and reliable finite element model was developed and verified...A numerical investigation of thin-walled complex section steel columns with intermediate stiffeners was performed using finite element analysis. An accurate and reliable finite element model was developed and verified against test results. Veri-fication indicates that the model could predict the ultimate strengths and failure modes of the tested columns with reasonable accuracy. Therefore,the developed model was used for the parametric study. In addition,the effect of geometric imperfection on column ultimate strength and the effect of boundary conditions on the elastic distortional buckling of complex section columns were investigated. An equation for the elastic distortional buckling load of fixed-ended columns having different column lengths was proposed. The elastic distortional buckling load obtained from the proposed equation was used in the direct strength method to calculate the column ultimate strength. Generally,it is shown that the proposed design equation conservatively predicted the ultimate strengths of complex section columns with different column lengths.展开更多
文摘This exploratory study examines whether genre has an impact on syntactic complexity and holistic rating in EFL writing. Over 300 sample texts produced by intermediate learners were collected from a test and some regular after-class assignments for English writing courses. Each participant completed two writing tasks, one argumentative and the other narrative. Results show that genre type has a significant impact on L2 syntactic complexity. Genre effect is found stronger with timed writing tasks. L2 holistic ratings show correlation with syntactic complexity on the different measure(s) depending on genre type and planning conditions. Regression analyses reveal that for timed writing tasks, clausal density(clauses per sentence) is a reliable predictor for holistic assessment on intermediate EFL learners’ writing quality. It is found to account for 6% of the score variance for timed writing and 10% for timed argumentative writing. Genre is evidenced to be related to EFL writing holistic ratings. Closer examination indicates that while syntactic complexity is predictive of holistic writing scores for argumentative writing, it does not correlate with holistic scores for narrative writing. Other linguistic features rather than syntactic complexity may be accountable. Overall, the study lends support to genre effect in the relationship between syntactic complexity and L2 writing quality holistic rating.
基金financially supported by the Applied Basic Research Projects(General Program)of Yunnan Province(2011FB015)
文摘Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali series. Petrology and geochemistry data indicate that the volcanic rocks may be formed in a continental rift environment. The volcanic rocks are in conformable contact with the overlying and underlying wall rocks, with such typical sedimentary structures as laminated and striped ones, and the host rocks of the volcanic rocks contain lots of marine fossils such as tentaculite. Many pieces of evidence indicate that the eruption environment of the volcanic rocks is a sea-facies one. The volcanic rocks are of the LREE-enrichment type, with high ratios of light rare-earth elements to heavy rare-earth elements. In addition, they display moderately negative δEu anomalies and moderately negative δCe anomalies with a higher degree of LREE and HREE fractionation. Through the Q-cluster analysis of the REE samples, it is indicated that the ores have a closer relation with the layered volcanic rocks, and also possess a certain inheritance-consistency relationship with the layered volcanic rocks. The source of ore-forming materials may be related with volcanism. It is proposed that the ore deposit in the study area should be genetically explained as the result of marine volcano-sedimentary exhalation of hot water and late superposition-reworking.
基金Projects(41172276,51279155)supported by the National Natural Science Foundation of ChinaProjects(106-00X101,106-5X1205)supported by the Central Financial Funds for the Development of Characteristic Key Disciplines in Local University,China
文摘A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account.
基金Supported by the National Natural Science Foundation of China (No.81900911)the National Key R&D Program of China (No.2016YFC0904800,No.2019YFC0840607)+1 种基金the National Science and Technology Major Project of China (No.2017ZX09304010)the Interdisciplinary Program of Shanghai Jiao Tong University (No.YG2019QN66)。
文摘AIM: To quantitatively analyze the retinal intermediate and deep capillary plexus(ICP and DCP) in patients with retinal deep vascular complex ischemia(RDVCI), using 3D projection artifacts removal(3D PAR) optical coherence tomography angiography(OCTA).METHODS: RDVCI patients and gender-and agematched healthy controls were assessed and underwent OCTA examinations. The parafoveal vessel density(PFVD) of retinal deep vascular complex(DVC), ICP, and DCP were analyzed, and the percentage of reduction(PR) of PFVD was calculated.RESULTS: Twenty-four eyes in 22 RDVCI patients(20 in acute phase and 4 in chronic phase) and 24 eyes of 22 healthy subjects were enrolled as the control group. Significant reduction of PFVD in DVC, ICP, and DCP was observed in comparison with the controls(DVC: acute: 43.59%±6.58% vs 49.92%±5.49%, PR=12.69%;chronic: 43.50%±3.33% vs 51.20%±3.80%, PR=15.04%. ICP: acute: 40.28%±7.91% vs 46.97%±7.14%, PR=14.23%;chronic: 41.48%±2.87% vs 46.43%±3.29%, PR=10.66%. DCP: acute: 45.44%±8.27% vs 51.51%±9.97%, PR=11.79%;chronic: 37.78%±3.48% vs 51.73%±5.17%, PR=26.97%;all P<0.05). No significant PR difference was found among DVC, ICP, and DCP of RDVCI in acute phase(P=0.812), but significant difference in chronic phase(P=0.006, DVC vs DCP, ICP vs DCP). No significant difference in PR between acute and chronic phases in the DVC(P=0.735) or ICP(P=0.681) was found, but significant difference in the DCP(P=0.041).CONCLUSION: The PFVD of DVC, ICP, and DCP in RDVCI is significantly decreased in both acute and chronic phases. ICP impairment is stabilized from acute to chronic phase in RDVCI, whereas subsequent DCP impairment is uncovered and can be explained by ischemia-reperfusion damage.
基金Under the auspices of Strategic Priority Research Program(A)of the Chinese Academy of Sciences(No.XDA28080503)National Natural Science Foundation of China(No.42071025)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2023240)。
文摘The‘human-land relationship’has long been a central topic in geography,ecology,and social sciences.And dynamic monit-oring of the land use/cover change(LUCC)and landscape pattern studies of land use provide essential theoretical support for this field.On the basis of physicogeographical regionalization and landscape ecology theory,this study proposed a method for characterizing land-scape pattern by using the minmium natural complex as the basic evaluation unit,constructing a four-level classification framework that included natural area,landscape region,landscape subregion,and landscape group.The method was tested in the Songhua River Basin,China,and the results revealed that:(1)the landscape pattern characterization in the Songhua River Basin validated the feasibility of the proposed method,and the use of the minimum natural complex as the basic measurement unit for landscape pattern characterization be-nefited research in this field.(2)The multiscale landscape pattern characterization system,which was framed around natural area,land-scape region,landscape subregion,and landscape group,accurately reflected the spatial heterogeneity of the physical geographic envir-onment and the impact of human activities on the landscape pattern in the Songhua River Basin.The nature-dominated landscape region was mainly concentrated in high-altitude mountainous and hilly areas,the human-dominated landscape region was located on plains and platforms,and the human-land interaction landscape region exhibited a landscape pattern that is closely related to natural factors such as temperature,precipitation,and soil.(3)The proposed method not only revealed the complex interactions between the physical geograph-ic environment and human activities but also provided scientific support for land use planning and ecological environment management.Future research should incorporate higher-resolution data and socioeconomic factors to further explore the dynamic changes in land-scape patterns and their impacts on the regional ecological environment.
基金Supported by the Commission of Science Technology and Industry for National Defense (J1600B001)
文摘The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of complex system are also given in this paper. Otherwise, the qualitative description of complex system is presented at first. On the basis of analyzing the existing brittleness problems, linguistic description and mathematic description of brittleness are given as well. Three kinds of phenomena to judge brittleness of complex system are also given, based on catastrophe theory. Basic characteristics of brittleness are given on the basis of its mathematic description. Two critical point sets are defined by using catastrophe theory. The definition of brittleness and its related theory can serve the control of complex system, and provide theoretical basis for the design and control of complex system.
基金supported by grants from the National Key Research and Development Program of China(2018YFD1000200)the National Natural Science Foundation of China(31972375)+2 种基金the Ministry of Agriculture of China(CARS-28)Shandong Province(SDAIT-06-03)Nanjing Agricultural University(ZW201805).
文摘Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica)has multiple functions,modulating both anthocyanin biosynthesis and cell acidification.Here,we show that MdbHLH3 also regulates ethylene biosynthesis and leaf senescence by promoting the expression of dehydratase-enolasephosphatase complex 1(MdDEP1).Therefore,we propose a model whereby MdbHLH3 acts as a crucial factor that modulates anthocyanin biosynthesis and cell acidification in addition to fruit ripening and leaf senescence by regulating distinct target genes.
基金DST-SERB grant vide Project No.CRG/2020/002635CSIR-JRF fellowship No.09/1236(11154)/2021-EMR-I。
文摘The Assam-Meghalaya Gneissic Complex(AMGC)of northeast India contains numerous Pan-African granitic bodies that have been attributed to post-collisional rift-related magmatism.The present study is concerned with the first appraisal of intermediate magmatism(diorite,monzonite,and monzodiorite)found in the Borjuri Pluton of Mikir Massif,which is the eastern extension of AMGC.The diorites are strongly metaluminous and exhibit enriched LREE([La/Yb]N=1.63–7.37)with respect to HREE([Gd/Yb]N=1.95–2.27).The studied rocks do not show any mineralogical or textural indication of metamorphism.Tectonic discrimination diagrams indicate that these rocks originated in a within-plate tectonic setting.The lower Mg#(33.49–38.69),low Cr(below detection limit),and Ni(27–41 ppm)contents along with elemental ratios such as Rb/Sr(0.32–0.95),La/Nb(0.49–4.21),and Nb/Ce(0.11–0.64)suggest a crustal source for the diorites.Discrimination diagrams coupled with elemental ratios suggest that these rocks originated due to partial melting of mafic components in the crust with possible contribution from mantle materials.The P–T conditions of diorite emplacement(7.4 kbar,688℃)were calculated using the amphibole-plagioclase geothermobarometer.Geochemical and geochronological data of the Pan-African felsic plutons reported from the AMGC indicate that these rocks were emplaced in a post-collisional extensional regime.The Borjuri Pluton is in close proximity with the Kathalguri Pluton,which has been reported as a product of PanAfrican magmatism.In view of the numerous extensional Pan-African felsic magmatism reported from the AMGC and based on the close vicinity of the Borjuri diorites with the Kathalguri granites,we speculate that the Borjuri diorites are products of the Pan-African post-collisional magmatism.
文摘Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+, FeO and MgO values are relatively high and the T, M3+, Fe2O3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2+ values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2+ and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2O3 and SiO2 in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10901145)the Natural Science Foundation of Shanxi Province,China(Grant Nos. 2009011005-1 and 2012011002-1)the Top Young Academic Leaders of Higher Learning Institutions of Shanxi Province,China
文摘In this paper,a sexually transmitted disease model is proposed on complex networks,where contacts between humans are treated as a scale-free social network.There are three groups in our model,which are dangerous male,non-dangerous male,and female.By mathematical analysis,we obtain the basic reproduction number for the existence of endemic equilibrium and study the effects of various immunization schemes about different groups.Furthermore,numerical simulations are undertaken to verify more conclusions.
文摘In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.
文摘Based on the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni（Ⅱ）-NH3-CO2-3-H2O system at ambient temperature were deduced theoretically and the thermodynamic diagrams of lg[Ni]T versus pH at different solution compositions were drawn, which was quite effective to explain the formation mechanism of precipitation particles with different microscopic shapes. When pH of the solution is below （7.0,） free nickel ions are dominant and when the precipitant is added, the fast coagulation will take place leading to the loose flocculation particles. While pH is above 7.0, because of the coordination of nickel ion with ammonia, the precipitation proceeds slowly accompanying with the release of Ni2+ from the multi-coordinated Ni（NH3）2+n（n=1, 2, …, 6）, which easily leads to the formation of the dense spherical particles.
基金Supported by the National Natural Science Foundation of China(No. 50478106)
文摘The complexation of Cr^3＋ with F^- undergoes a muhistep reversible process. An approach to research the involved equilibria and kinetics using suitable chemometrics methods to the online measured UV-Vis spectra is proposed. By investigating the equilibrium spectra of the complexes at different molar ratios of M to L（ metal to ligand） and 50 ℃, the result of Principal Component Analysis（PCA） shows that three complexes, ML, ML2 and ML3, can be formed under the research conditions. The spectrum of each complex was then analyzed and the accumulated equilibrium constants were calculated by applying Target Testing Factor Analysis（TITA）. Meanwhile, a reactive intermediate was observed before the formation of MLx during the specific kinetic study at 15℃. The equilibrium constant and spectrum of the intermediate as well as the rate constants were all resolved by using TTFA.
基金Project supported by the Department of Education of Zhejiang Province (No.Y200804537)the Zhejiang University Zijin Project,and the Zhejiang College of Construction (No.200914), China
文摘A numerical investigation of thin-walled complex section steel columns with intermediate stiffeners was performed using finite element analysis. An accurate and reliable finite element model was developed and verified against test results. Veri-fication indicates that the model could predict the ultimate strengths and failure modes of the tested columns with reasonable accuracy. Therefore,the developed model was used for the parametric study. In addition,the effect of geometric imperfection on column ultimate strength and the effect of boundary conditions on the elastic distortional buckling of complex section columns were investigated. An equation for the elastic distortional buckling load of fixed-ended columns having different column lengths was proposed. The elastic distortional buckling load obtained from the proposed equation was used in the direct strength method to calculate the column ultimate strength. Generally,it is shown that the proposed design equation conservatively predicted the ultimate strengths of complex section columns with different column lengths.
