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Interaction effects of flotation reagents for SAG mill reject of copper sulphide ore using response surface methodology 被引量:7
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作者 Ali AHMADI Mojtaba REZAEI Seyed Mohammad SADEGHIEH 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第3期792-806,共15页
Flotation reagents have a complex behaviour in the beneficiation of base minerals in clayey ores.Interaction effects of reagents on the efficiency of copper flotation for a highly clayey low-grade sulphide ore were in... Flotation reagents have a complex behaviour in the beneficiation of base minerals in clayey ores.Interaction effects of reagents on the efficiency of copper flotation for a highly clayey low-grade sulphide ore were investigated using a central composite design.Preliminary results showed that sodium-isopropyl-xanthate(SIPX)and O-isopropyl-N-ethyl-thionocarbamate(IPETC)were found to be the most efficient collectors in the presence of lime as the pH regulator.The effects of dosage of collectors(SIPX and IPETC)and the dosage of methyl-isobutyl-carbonyl(MIBC)as frother on the separation efficiency were evaluated at different pH levels.Based on the analysis of variance(ANOVA),the interaction effects of the collector−pH and collector−frother were significant for the separation efficiency.At the low level of collector dosage,increasing pH from 9 to 11 enhanced copper separation efficiency from 81%to 86%for IPETC and from 77%to 86%for SIPX.Results of ANOVA showed that the maximum copper separation efficiency(88.7%)was obtained at the dosages of 8.6 g/t SIPX,7 g/t IPETC and 20 g/t MIBC at pH 11.Finally,it was concluded that a mixture of SIPX and IPETC collectors was more suitable to treat highly clayey sulphide ores. 展开更多
关键词 FLOTATION copper sulphide REAGENT interaction effect reject ore
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Analysis on Interaction Effects Between Variety and Site of Silage Maize Regional Test in Guizhou Province 被引量:1
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作者 SHU Zhong-bing GOU Xiao-song +2 位作者 CHEN Lang WANG Chun-mei REN Hong 《Agricultural Science & Technology》 CAS 2022年第1期11-16,共6页
Taking the yield in the second group of Guizhou silage maize regional test in 2019 as data information, 8 experimental sites and 12 silage maize varieties as experimental objects, the interaction effect between gene a... Taking the yield in the second group of Guizhou silage maize regional test in 2019 as data information, 8 experimental sites and 12 silage maize varieties as experimental objects, the interaction effect between gene and environment was analyzed by using AMMI model. The results showed that the average fresh weight yield of each variety was 3 199.5~3 976.6 kg/667m^(2), among them, 5 varieties had an increase in the yield. Variety variation accounted for 10.51% of the total variation;experimental site variation accounted for 63.22% of the total variation;interaction effect variation between gene and environment accounted for 26.28% of the total variation;IPCA1 and IPCA2 variation accounted for 50.7% and 31.2% of the interaction variation, respectively;IPCA3 variation accounted for 7.25% of the interaction variation. g_4, g_8, g_9, g_10, g_11 and g_12 had better adaptability to e_1, e_2, e_6 and e_7;while g_1, g_2, g_3, g_5, g_6 and g_7 had better adaptability to e_3, e_4, e_5 and e_8. In consideration of yield, g_1(Huinongqing 2) and g_9(Xinyu 666) were silage maize varieties with high and stable yield;g_3(Hemuyu 905), g_8(Wuhuayu 3) and g_11(Liangdu 191) had general stability, and their yield was higher than that of the control;g_12(Jinduyu 999) had the worst stability and low yield. 展开更多
关键词 Silage maize AMMI model GENE ENVIRONMENT interaction effect
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Interaction effects on heat conduction and thermal stress in an infinite elastic plane with two circular holes
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作者 Kun SONG Deshun YIN +1 位作者 Haibing YANG P.SCHIAVONE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第2期223-234,共12页
Numerous researches have focused on the physical behavior of an elastic material in the vicinity of a single hole under the assumption that the interaction effects arising from the introduction of multiple holes remai... Numerous researches have focused on the physical behavior of an elastic material in the vicinity of a single hole under the assumption that the interaction effects arising from the introduction of multiple holes remain negligible if the holes are placed sufficiently far from each other.In an effort to understand hole interaction effects on heat conduction and thermal stress,we consider the case when two circular holes are embedded in an infinite elastic material and use complex variable methods together with numerical analysis to obtain solutions describing temperature and elastic fields in the vicinity of the two circular holes.The results indicate that the interaction effects on temperature distribution and stress strongly depend on the relative size of the two holes and the distance placed between them but not on the actual size of the holes. 展开更多
关键词 heat conduction temperature field thermal stress interaction effect two circular holes
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Remote electron effects and π-π interactions of α-diimine nickel complexes
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作者 Yizhan Wang Hailong He Dan Peng 《中国科学技术大学学报》 CAS CSCD 北大核心 2024年第9期17-22,68,共7页
The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nick... The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nickel-based catalysts have great application prospects in the industrialization process of olefin coordination polymerization.In this work,various N-aryl substituents with different electronic effects were synthesized and introduced intoα-diimine ligands.The aspreparedα-diimine nickel catalysts showed high polymerization activity(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1))in ethylene polymerization,generating polyethylene products with adjustable molecular weights(Mn values:7.4×10^(4)–146.9×10^(4)g·mol^(−1))and branching densities(31/1000 C–68/1000 C).The resulting polyethylene products showed excellent mechanical properties,with high tensile strength(up to 25.0 MPa)and high strain at break values(up to 3890%).The copolymerization of ethylene and polar monomers can also be achieved by these nicekel complexes,ultimately preparing functionalized polyolefins. 展开更多
关键词 α-diimine nickel catalyst ethylene polymerization π-πinteraction effect electronic effect polar monomer
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Independent and interactive effects of N and P additions on foliar P fractions in evergreen forests of southern China 被引量:1
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作者 Qingquan Meng Zhijuan Shi +3 位作者 Zhengbing Yan Hans Lambers Yan Luo Wenxuan Han 《Forest Ecosystems》 2025年第1期66-73,共8页
Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P... Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P fractions is potentially an adaptive strategy for plants to cope with soil N(P)availability and nutrient-limiting conditions.However,the impact of the interactions between imbalanced anthropogenic N and P inputs on the concentrations and allocation proportions of leaf P fractions in forest woody plants remains elusive.We conducted a metaanalysis of data about the concentrations and allocation proportions of leaf P fractions,specifically associated with individual and combined additions of N and P in evergreen forests,the dominant vegetation type in southern China where the primary productivity is usually considered limited by P.This assessment allowed us to quantitatively evaluate the effects of N and P additions alone and interactively on leaf P allocation and use strategies.Nitrogen addition(exacerbating P limitation)reduced the concentrations of leaf total P and different leaf P fractions.Nitrogen addition reduced the allocation to leaf metabolic P but increased the allocation to other fractions,while P addition showed opposite trends.The simultaneous additions of N and P showed an antagonistic(mutual suppression)effect on the concentrations of leaf P fractions,but an additive(summary)effect on the allocation proportions of leaf P fractions.These results highlight the importance of strategies of leaf P fraction allocation in forest plants under changes in environmental nutrient availability.Importantly,our study identified critical interactions associated with combined N and P inputs that affect leaf P fractions,thus aiding in predicting plant acclimation strategies in the context of intensifying and imbalanced anthropogenic nutrient inputs. 展开更多
关键词 Anthropogenic nutrient inputs Individual and combined effects Interactive effects Leaf phosphorus fractions Nitrogen and phosphorus additions Nutrient-utilization strategies Woody plants
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Analysis of Genetic Effects of Nuclear-Cytoplasmic Interaction on Quantitative Traits:Genetic Model for Diploid Plants
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作者 韩立德 杨剑 朱军 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第6期562-568,共7页
A genetic model was proposed for simultaneously analyzing genetic effects of nuclear, cytoplasm, and nuclear-cytoplasmic interaction (NCI) as well as their genotype by environment (GE) interaction for quantitative... A genetic model was proposed for simultaneously analyzing genetic effects of nuclear, cytoplasm, and nuclear-cytoplasmic interaction (NCI) as well as their genotype by environment (GE) interaction for quantitative traits of diploid plants. In the model, the NCI effects were further partitioned into additive and dominance nuclear-cytoplasmic interaction components. Mixed linear model approaches were used for statistical analysis. On the basis of diallel cross designs, Monte Carlo simulations showed that the genetic model was robust for estimating variance components under several situations without specific effects. Random genetic effects were predicted by an adjusted unbiased prediction (AUP) method. Data on four quantitative traits (boll number, lint percentage, fiber length, and micronaire) in Upland cotton (Gossypium hirsutum L.) were analyzed as a worked example to show the effectiveness of the model. 展开更多
关键词 Plants traits genetic model nuclear-cytoplasmic interaction effects GE interaction genetic prediction
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Effects of the Interaction between Hydroxyapatite Nanoparticles and Hepatoma Cells 被引量:1
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作者 尹美珍 XU Weiguo +4 位作者 CUI Bingcun 戴红莲 HAN Yingchao YIN Yixia LI Shipu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第3期635-642,共8页
To gain a better understanding of the anticancer effects of hydroxyapatite (HAP) nanoparticles in vivo and in vitro, the effects of the interaction of HAP nanoparticles with hepatoma cells were explored. HAP nanopar... To gain a better understanding of the anticancer effects of hydroxyapatite (HAP) nanoparticles in vivo and in vitro, the effects of the interaction of HAP nanoparticles with hepatoma cells were explored. HAP nanoparticles were prepared by homogeneous precipitation and characterized by laser particle analysis and transmission electron microscopy (TEM). HAP nanoparticles were observed to be uniformly distributed, with rod-like shapes and diameters in the range of 42.1-87.1 nm. Overnight attached, suspended, and proliferating Bel-7402 cells were incubated with HAP nanoparticles. Inverted microscopy observation revealed that HAP nanoparticles with a cell membrane showed good adsorption. TEM demonstrated that HAP nanoparticles were present on the surface of cells, continuously taken up by cells through endocytosis, and transported in vesicles close to the nucleus. Fluorescence microscopy showed that the concentrations of intracellular Ca2+ labeled with Fluo-3 calcium fluorescent probe were significantly enhanced. In addition, inverted microscopy observation revealed that suspended cells treated with HAP nanoparticles did not adhere to the culture bottle, resulting in cell death. After the overnight attached cells were treated with HAP nanoparticles for 96 h with increasing doses of HAP nanoparticles, inverted microscopy observation revealed that cell proliferation was slowed and ceU-ceU adhesion was weakened. Feulgen staining and image analysis indicated that the nuclear DNA content of the cells was markedly reduced, and argyrophilic nucleolar organizer region (AgNOR) staining and image analysis indicated that the number of AgNORs was significantly decreased. Therefore, hepatoma cells brought about the adsorption, uptake, transport and degradation of HAP nanoparticles. In addition, HAP nanoparticles affected hepatoma cells with regard to cell-cell adhesion, cell and extracellular matrix adhesion, and DNA and protein synthesis; thus inhibiting cell proliferation. This understanding of the effects of interaction between HAP nanoparticles and hepatoma cells is useful for further study of the anticancer mechanisms of HAP nanoparticles. 展开更多
关键词 hydroxyapatite nanoparticles hepatoma cells interaction effects cell adhesion
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A comparison of two wave energy converters’power performance and mooring fatigue characteristics-One WEC vs many WECs in a wave park with interaction effects
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作者 Xinyuan Shao Jonas W.Ringsberg +3 位作者 Hua-Dong Yao Zhiyuan Li Erland Johnson Göran Fredriksson 《Journal of Ocean Engineering and Science》 SCIE 2023年第4期446-460,共15页
The production of renewable energy is key to satisfying the increasing demand for energy without further increasing pollution.Harnessing ocean energy from waves has attracted attention due to its high energy density.T... The production of renewable energy is key to satisfying the increasing demand for energy without further increasing pollution.Harnessing ocean energy from waves has attracted attention due to its high energy density.This study compares two generations of floating heaving point absorber WEC,WaveEL 3.0 and WaveEL 4.0,regarding their power performance and mooring line fatigue characteristics,which are essen-tial in,e.g.,LCoE calculations.The main differences between the two WECs are the principal dimensions and minor differences in their geometries.The DNV software SESAM was used for simulations and anal-yses of these WECs in terms of buoy heave motion resonances for maximising energy harvesting,motion characteristics,mooring line forces,fatigue of mooring lines,and hydrodynamic power production.The first part of the study presents results from simulations of unit WEC in the frequency domain and in the time domain for regular wave and irregular sea state conditions.A verification of the two WECs’motion responses and axial mooring line forces is made against measurement data from a full-scale installation.In the second part of the study,the influence of interaction effects is investigated when the WECs are installed in wave parks.The wave park simulations used a fully-coupled non-linear method in SESAM that calculates the motions of the WECs and the mooring line forces simultaneously in the time domain.The amount of fatigue damage accumulated in the mooring lines was calculated using a relative tension-based fatigue analysis method and the rainflow counting method.Several factors that influence the power performance of the wave park and the accumulated fatigue damage of the mooring lines,for example,the WEC distance of the wave park,the sea state conditions,and the direction of incoming waves,are simulated and discussed.The study’s main conclusion is that WaveEL 4.0,which has a longer tube than WaveEL 3.0,absorbs more hydrodynamic energy due to larger heave motions and more efficient power production.At the same time,the accumulated fatigue damage in the moorings is lower compared to WaveEL 3.0 if the distance between the WECs in the wave park is not too short.Its motions in the hor-izontal plane are larger,which may require a larger distance between the WEC units in a wave park to avoid losing efficiency due to hydrodynamic interaction effects. 展开更多
关键词 Heaving point absorber interaction effects Mooring fatigue Power performance analysis Wave energy
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Coupling effects of depletion interactions in a three-sphere colloidal system
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作者 陈泽顺 戴刚 +1 位作者 高海峡 肖长明 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第5期587-590,共4页
In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result ... In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result in a strengthened depletion force. So the difference of the depletion forces of the three-sphere system and its corresponding two two-sphere systems is introduced to describe the coupling effect of the depletion interactions. The numerical results obtained by Monte- Carlo simulations show that this coupling effect is affected by both the concentration of small spheres and the geometrical confinement. Meanwhile, it is also found that the mechanisms of the coupling effect and the effect on the depletion force from the ~eometry factor are the same. 展开更多
关键词 three-sphere system coupling effect of depletion interactions
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Effects of Pure Dzyaloshinskii-Moriya Interaction with Magnetic Field on Entanglement in Intrinsic Decoherence
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作者 李大创 王先萍 +3 位作者 李虎 李小曼 杨名 曹卓良 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第5期1-4,共4页
We investigate the effects of pure Dzyaloshinskii Moriya (DM) interaction with magnetic field on entanglement in intrinsic decoherence, assuming that the system is initially in four Bell states |φ±〉 = (|00... We investigate the effects of pure Dzyaloshinskii Moriya (DM) interaction with magnetic field on entanglement in intrinsic decoherence, assuming that the system is initially in four Bell states |φ±〉 = (|00) ± |11〉)/√2 and |ψ±〉 = (|01) ±|10〉)/√2, respectively. It is found that if the system is initially in the state p1(0) = |φ+〉〈φ+1, the entanglement can obtain its maximum when the DM interaction vector D is in the plane of XOZ and magnetic field B = By with the infinite time t, moreover the entanglement is independent of By and t when By is perpendicular to D. In addition, we obtain similar results when the system is initially in the states p2(0) = |φ-〉〈φ-| or p3 (0) = |ψ+〉〈ψ+1. However, we find that if the system is initially in the state P4 (0) = |ψ-〉〈ψ-l, the entanglement can obtain its maximum for infinite t, when the DM vector is in the plane ofYOZ, XOZ, or XOY, with the magnetic field parallel to X, Y, or Z axis, respectively. Moreover, when the axial B is perpendicular to D for the initial state p4(O), the negativity oscillates with time t and reaches a stable value, the larger the value of B is, the greater the stable value is, and the shorter the oscillation time of the negativity is. Thus we can adjust the direction and value of the external magnetic field to obtain the maximal entanglement, and avoid the adverse effects of external environment in some initial state. This is feasible within the cun'ent experimental technology. 展开更多
关键词 of in DM effects of Pure Dzyaloshinskii-Moriya interaction with Magnetic Field on Entanglement in Intrinsic Decoherence IS with on
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Bootstrap inference of the skew-normal two-way classification random effects model with interaction
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作者 YE Ren-dao AN Na +1 位作者 LUO Kun LIN Ya 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2022年第3期435-452,共18页
In this paper,we consider the statistical inference problems for the fixed effect and variance component functions in the two-way classification random effects model with skewnormal errors.Firstly,the exact test stati... In this paper,we consider the statistical inference problems for the fixed effect and variance component functions in the two-way classification random effects model with skewnormal errors.Firstly,the exact test statistic for the fixed effect is constructed.Secondly,using the Bootstrap approach and generalized approach,the one-sided hypothesis testing and interval estimation problems for the single variance component,the sum and ratio of variance components are discussed respectively.Further,the Monte Carlo simulation results indicate that the exact test statistic performs well in the one-sided hypothesis testing problem for the fixed effect.And the Bootstrap approach is better than the generalized approach in the one-sided hypothesis testing problems for variance component functions in most cases.Finally,the above approaches are applied to the real data examples of the consumer price index and value-added index of three industries to verify their rationality and effectiveness. 展开更多
关键词 skew-normal two-way classification random effects model with interaction fixed effect variance component functions BOOTSTRAP generalized approach
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Neuroimmune actions in the brain and interactions with the effects of alcohol
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作者 Donna L.Gruol 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第9期1791-1792,共2页
The neuroimmune system of the brain:Early studies(1990’s)on the neurological consequences of human immunodeficiency virus-1(HIV-1)infection in the brain were instrumental in establishing that specific brain cell type... The neuroimmune system of the brain:Early studies(1990’s)on the neurological consequences of human immunodeficiency virus-1(HIV-1)infection in the brain were instrumental in establishing that specific brain cell types can function as an innate immune system within the brain and in that role influence cognitive function(Kaul et al.,2005). 展开更多
关键词 Neuroimmune actions in the brain and interactions with the effects of alcohol
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Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of MnZn Ferrites
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作者 M.M.Abou Sekkina(Chem. Dept., Faculty of Science, Tanta University, Tanta, Egypt)A.M.El-Sayed(Inorganic Chemistry Dept., National Research Centre, Dokki, Cairo, Egypt) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1997年第6期467-470,共4页
Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spi... Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism. 展开更多
关键词 effects of Hyperfine and Dopant Cation interactions on theDC-Electrical Conductivity of MnZn Ferrites
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QTL Mapping and Q×E Interactions of Grain Cooking and Nutrient Qualities in Rice Under Upland and Lowland Environments 被引量:2
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作者 郭咏梅 穆平 +2 位作者 刘家富 卢义宣 李自超 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第5期420-428,共9页
Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the pheno... Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the phenotypic values and potential QTLs for the quality traits. The cooking and nutrient quality traits, including the amylose content (AC), the gel consistency (CJC), the gelatinization temperature (GT), and the protein content (PC), in rice grown under upland and lowland environments were evaluated. Significant differences for AC, GC, GT, and PC between upland and lowland environments were detected. The phenotypic values of all four traits were higher under upland environment than lowland environment. The value of PC under upland environment was significantly higher (by 37.9%) than that under lowland environment. This suggests that upland cultivation had large effect on both cooking and nutrient qualifies. A total of seven QTLs and twelve pairs of QTLs were detected to have significant additive and epistatic effects for the four traits. Significant Q x E interaction effects of two QTLs and two pairs of QTLs were also discovered. The general contribution of additive QTLs ranged from 1.91% to 19.77%. The Q × E interactions of QTLs QGt3 and QAc6 accounted for 8.99% and 47.86% of the phenotypic variation, respectively, whereas those of the 2 pairs of epistatic QTLs, QAc6-QAcllb and QAc8-QAc9, accounted for 32.54% and 11.82%, respectively. Five QTLs QGt6b, QGt8, QGt11, QGcl, and QPc2, which had relatively high general contribution and no Q x E interactions, were selected to facilitate the upland rice grain quality breeding. 展开更多
关键词 upland rice cooking quality nutrient quality QTL mapping Q × E interaction effects
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Joint Effects and Spatiotemporal Characteristics of the Driving Factors of Landslides in Earthquake Areas 被引量:6
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作者 Jintao Yang Chong Xu Xu Jin 《Journal of Earth Science》 SCIE CAS CSCD 2023年第2期330-338,共9页
Understanding the joint effects of earthquakes and driving factors on the spatial distribution of landslides is helpful for targeted disaster prevention and mitigation in earthquake-prone areas.By far,little work has ... Understanding the joint effects of earthquakes and driving factors on the spatial distribution of landslides is helpful for targeted disaster prevention and mitigation in earthquake-prone areas.By far,little work has been done on this issue.This study analyzed the co-seismic landslide of the Ms8.0 Wenchuan earthquake in 2008 and 2014.The joint effects and spatiotemporal characteristics of the driving factors in seismic regions were revealed.Results show that(a)between 2008 and 2014,the dominant driving-factor for landslides has changed from earthquake to rock mass;(b)driving factors with weak driving force have a significant enhancement under the joint effects of other factors;(c)the joint effects of driving factors and earthquake decays with time.The study concluded that the strong vibration of the Wenchuan earthquake and the rock mass strength are the biggest contributors to the spatial distribution of landslides in 2008 and 2014,respectively.It means that the driving force of the earthquake is weaker than that of the rock mass after six years of the Wenchuan earthquake.Moreover,the landslide spatial distribution can be attributed to the joint effects of the Wenchuan earthquake and driving factors,and the earthquake has an enhanced effect on other factors. 展开更多
关键词 geodetector co-seismic landslide spatial pattern triggering factors interaction effects driving force engineering geology
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Comparative study between crack closure model and Willenborg model for fatigue prediction under overload effects
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作者 Jiang Shan Zhang Wei +1 位作者 He Jingjing Wang Zili 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第6期1618-1625,共8页
A comparative study is performed between a crack closure model and the Willenborg model, which can calculate the fatigue crack growth rate under the overload effects. The modified virtual crack annealing(VCA) model is... A comparative study is performed between a crack closure model and the Willenborg model, which can calculate the fatigue crack growth rate under the overload effects. The modified virtual crack annealing(VCA) model is briefly reviewed, which is based on the equivalent plastic zone concept. In this method, the retardation phenomenon is explained by the crack closure level variation, which is derived from the interactions between forward and reverse plastic zones ahead of the crack tip. As a comparison, the Forman equation in conjunction with the Willenborg model is also reviewed. The retardation phenomenon is described by directly modifying the stress intensity factor. It is known that the large plastic zone created by the overload can decelerate the fatigue crack growth rate until the crack grows beyond this region. A relationship between the plastic zone and the modified stress intensity factor is developed, which is a mathematical fitting equation instead of physical-based formulation. The experimental data in aluminum alloys are used to validate these two models. Overall, good agreement is observed between the model predictions and the testing data. It is noted that the approach based on modified VCA model can give more accurate prediction curves than the Willenborg model. 展开更多
关键词 Crack closure Fatigue crack growth interaction effects OVERLOADS Plastic zone
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Paired nitrogen management for improving wheat yields while minimizing nitrogen losses
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作者 Xiaotian Mi Wanyi Xie +3 位作者 Lei Fan Tianli Zhang Yaru Liu Gang He 《Journal of Integrative Agriculture》 2025年第9期3626-3640,共15页
Excellent nitrogen(N)management techniques can improve crop yields while mitigating reactive N(Nr)losses.The synergistic effects of applying paired N management techniques have important implications for designing exc... Excellent nitrogen(N)management techniques can improve crop yields while mitigating reactive N(Nr)losses.The synergistic effects of applying paired N management techniques have important implications for designing excellent N management strategies,but the interaction effects remain poorly known.Here,a meta-analysis was conducted to quantify the effects of optimized N management techniques(optimized N application rate,optimized topdressing,and applying enhanced-efficiency fertilizers)on wheat yield,N use efficiency(NUE),and Nr losses,as well as the interactive effects of paired N management techniques(combining an optimized N rate with topdressing or enhanced-effciency fertilizers).The results demonstrated that an optimized N fertilizer rate reduced Nr losses by 28-31%while the wheat yield declined by 2%;however,the wheat yield increased by 2%when the reduction of N fertilizer was less than 20%.The adoption of topdressing and enhancedeffciency fertilizers signifcantly increased wheat yields by 4-8%and NUE by 8-14%,while reducing Nr losses by 28-40%,and high topdressing frequency and nitrifcation inhibitors showed stronger positive effects on wheat yield.Paired N management techniques increased wheat yields by 3-4%and NUE by 37-38%,with additive or synergistic effects;and they also reduced Nr losses by 5-66%but showed an antagonistic effect.Such nonadditive interactions amplifed the positive effects on wheat production,but the benefts in terms of environmental risk reduction were weakened.Overall,this study highlights the importance of synergistic effects in innovative N management to address the trade-off between crop yield and Nr losses. 展开更多
关键词 crop productivity N application rate optimized topdressing enhanced-efficiency fertilizers interaction effect
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Impact of warming and nitrogen addition on soil greenhouse gas fluxes:A global perspective
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作者 Hongze Ma Xiaoyu Jia +6 位作者 Weiguang Chen Jingyi Yang Jin Liu Xiaoshan Zhang Ke Cui Zhouping Shangguan Weiming Yan 《Journal of Environmental Sciences》 2025年第5期88-99,共12页
Global warming and nitrogen(N)deposition have a profound impact on greenhouse gas(GHG)fluxes and consequently,they also affect climate change.However,the global combined effects of warming and N addition on GHG fluxes... Global warming and nitrogen(N)deposition have a profound impact on greenhouse gas(GHG)fluxes and consequently,they also affect climate change.However,the global combined effects of warming and N addition on GHG fluxes remain to be fully understood.To address this knowledge gap,a globalmeta-analysis of 197 datasets was performed to assess the response of GHG fluxes to warming and N addition and their interactions under various climate and experimental conditions.The results indicate that warming significantly increased CO_(2)emissions,while N addition and the combined warming and N addition treatments had no impact on CO_(2)emissions.Moreover,both warming and N addition and their interactions exhibited positive effects on N_(2)O emissions.Under the combined warming and N addition treatments,warming was observed to exert a positive main effect on CO_(2)emissions,while N addition had a positive main effect on N_(2)O emissions.The interactive effects of warming and N addition exhibited antagonistic effects on CO_(2),N_(2)O,and CH_(4)emissions,with CH_(4)uptake dominated by additive effects.Furthermore,we identified biome and climate factors as the two treatments.These findings indicate that both warming and N addition substantially impact soil GHG fluxes and highlight the urgent need to investigate the influence of the combination of warming and N addition on terrestrial carbon and N cycling under ongoing global change. 展开更多
关键词 WARMING Nitrogen(N)addition Greenhouse gas(GHG)fluxes Interactive effects BIOME
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Stress disturbance induced by twin-tunneling in sandy ground considering soil arching effect
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作者 Zhiyong Liu Xuanda Wu +2 位作者 Junhua Xiao Jinghui Yang Ying Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6530-6547,共18页
Due to space constraints in urban areas,metro tunnels are typically constructed in pairs,with a small clearance.The interaction between twin tunnels leads to a significantly more complex ground deformation and stress ... Due to space constraints in urban areas,metro tunnels are typically constructed in pairs,with a small clearance.The interaction between twin tunnels leads to a significantly more complex ground deformation and stress distribution than that observed in a single tunnel scenario,particularly if the tunnels are excavated in sequence.A series of physical model tests were conducted to investigate soil deformation and stress disturbances caused by the excavation of twin tunnels.The test results indicate that the interaction between the twin tunnels was observed.Due to the soil arching effect,the excavation of Tunnel 2 increases the soil stress acting on Tunnel 1.An analytical method was proposed to determine soil stress considering the soil arching effect and the interaction between twin tunnels.The method categorized the relative locations between twin tunnels into non-influenced,partially influenced,and fully influenced scenarios.For non-influenced and fully influenced scenarios,the soil stresses above twin tunnels were calculated based on a symmetric major principal stress trace.For the partially influenced scenario,however,the soil arch above Tunnel 2 was asymmetric due to the interaction,and the stress distribution was obtained based on a new asymmetric major principal stress trace.The soil stress on Tunnel 1 was influenced by the load transferred from Tunnel 2 and calculated based on the force equilibrium.A comparison of the analytical and test results indicates that the proposed method effectively predicts the soil stress in the cover layer above twin tunnels excavated sequentially,considering the interaction and soil arching effects. 展开更多
关键词 Physical model tests Analytical method Soil stress Twin tunnels in sandy ground interaction and soil arching effect
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A proposal for the theoretical analysis of the interactive coupled effects between urbanization and the eco-environment in mega-urban agglomerations 被引量:43
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作者 FANG Chuanglin ZHOU Chenghu +2 位作者 GU Chaolin CHEN Liding LI Shuangcheng 《Journal of Geographical Sciences》 SCIE CSCD 2017年第12期1431-1449,共19页
Mega-urban agglomerations are strategic core areas for national economic development and the main regions of new urbanization. They also have important roles in shifting the global economic center of gravity to China.... Mega-urban agglomerations are strategic core areas for national economic development and the main regions of new urbanization. They also have important roles in shifting the global economic center of gravity to China. However, the development of mega-urban agglomerations has triggered the interactive coercion between resources and the eco-envi- ronment. The interactive coupled effects between urbanization and the eco-environment in mega-urban agglomerations represent frontier and high-priority research topics in the field of Earth system science over the next decade. In this paper, we carried out systematic theo- retical analysis of the interactive coupling mechanisms and coercing effects between ur- banization and the eco-environment in mega-urban agglomerations. In detail, we analyzed the nonlinear-coupled relationships and the coupling characteristics between natural and human elements in mega-urban agglomerations. We also investigated the interactive coercion intensities between internal and external elements, and the mechanisms and patterns of local couplings and telecouplings in mega-urban agglomeration systems, which are affected by key internal and external control elements. In addition, we proposed the interactive coupling theory on urbanization and the eco-environment in mega-urban agglomerations. Furthermore we established a spatiotemporal dynamic coupling model with multi-element, multi-scale, multi-scenario, multi-module and multi-agent integrations, which can be used to develop an intelligent decision support system for sustainable development of mega-urban agglomera- tions. In general, our research may provide theoretical guidance and method support to solve problems related to mega-urban agglomerations and maintain their sustainable development. 展开更多
关键词 mega-urban agglomeration URBANIZATION ECO-ENVIRONMENT interactive coupled effects coupling theory process of theoretical analysis
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