Objective Analyzing the nonlinear dynamics of the TCP-RED congestion control system is of great importance. This study will help investigate the loss of stability in Internet and design a proper method for controlling...Objective Analyzing the nonlinear dynamics of the TCP-RED congestion control system is of great importance. This study will help investigate the loss of stability in Internet and design a proper method for controlling bifurcation and chaos in such system. Methods Based on bifurcation diagram, the effect of parameter on system performance is discussed. By using the state feedback and parameter variation strategy, a simple real time control method is proposed to modify the existing RED scheme. Results With our control method, the parametric sensitivity of RED mechanism is attenuated. Moreover, a sufficient condition on the robust stability of the system is also derived to adjust the parameters in TCP-RED system. Conclusion The proposed method has the advantages of simple implementation and unnecessary knowledge of the exact system.展开更多
To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM ...To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM methods,and a novel hydrothermal process based on the conversion principle was finally proposed.The crystal structure simulation shows that the HA with varied silicon saturation coefficients is more stable than HG,and the HA with a high iron substitution coefficient is more difficult to be converted from HG.The(110)plane of Fe_(2)O_(3) is easier to combine with HG to form HA,and the binding energy is 81.93 kJ/mol.The effects of raw material ratio,solution concentration and hydrothermal parameters on the conversion from HG to HA were revealed,and the optimal conditions for the alumina recovery were obtained.The recovery efficiencies of alumina and Na_(2)O from the RM are 63.06%and 97.34%,respectively,and the Na_(2)O content in the treated RM is only 0.13%.展开更多
The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color...The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.展开更多
In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarch...In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.展开更多
To improve the applicability of red mud in subgrade construction,we studied the effects of four traditional retarders,including borax,sodium hexametaphosphate,sodium gluconate,and sucrose,on the setting time,mechanica...To improve the applicability of red mud in subgrade construction,we studied the effects of four traditional retarders,including borax,sodium hexametaphosphate,sodium gluconate,and sucrose,on the setting time,mechanical properties and soil solidification of red mud-based subgrade engineered cementitious material(RCM).The mechanisms of the retarders on the hydration process of RCM were analyzed by hydration microcalorimeter,XRD,TG,and SEM-EDS.The experimental results show that four retarders have retarding effect on RCM,among which sodium gluconate and sucrose have significant retarding effect and do not have adverse effect on 28 d strength.Borax can slightly delay the setting time,and sodium hexametaphosphate has a better retarding effect,but they both reduce the 28 d strength.Microcosmic analysis shows that the retarders do not change the type of RCM hydration products,but mainly slow down the rate of hydration reaction through the adsorption and complexation or reaction of Ca^(2+)in the slurry.All the results show that the retarder has no weakening effect on the unconfined compressive strength,water stability and CBR properties of the stabilized subgrade soil based on RCM.展开更多
Plants constitute nearly 80%of the planet’s total biomass(Bar-On et al.,2018);however,this vital group is experiencing severe threats,and recent evaluations indicate that approximately 45%of the world's described...Plants constitute nearly 80%of the planet’s total biomass(Bar-On et al.,2018);however,this vital group is experiencing severe threats,and recent evaluations indicate that approximately 45%of the world's described plant species are at risk of extinction(Bachman et al.,2024).The number of plant extinctions has increased by 60%in the last 100 years(Di Marco et al.,2017).Over the past 250 years,571 plant species have gone extinct—more than twice the combined total of extinct birds,mammals,and amphibians(217 species)(Briggs,2019).展开更多
Understanding the shakedown behavior of fill material is paramount to estimate the deformation stability of railway subgrade.Especially for red mudstone fill material(RMF),the noticeable overestimation of bearing capa...Understanding the shakedown behavior of fill material is paramount to estimate the deformation stability of railway subgrade.Especially for red mudstone fill material(RMF),the noticeable overestimation of bearing capacity would be encountered if the conventional strength method is used.This paper presents the shakedown analysis on RMF,with a specific emphasis on the effect of water content.A series of cyclic triaxial tests with 50,000 loading cycles was conducted.Two-stage behavior of permanent deformation and dissipated energy responses was clearly characterized,from which an energy-based criterion was proposed to determine the shakedown limits.The proposed energy-based criterion was validated by examining its performance to various geomaterials including cohesive soils and unbound granular materials(UGMs).By applying the proposed method to RMF,the S-shape evolution curve was obtained in terms of shakedown limits with initial suction.Microfabric difference was believed as the main consequence of the S-shape mode.Demonstration was confirmed by the mercury intrusion porosimetry(MIP)and scanning electron microscope(SEM)analyses.By applying the proposed method to different geomaterials,an extensive comparison was made between the shakedown limits and the static shear strength.The ratio of shakedown limits to the static shear strength for saturated RMF specimen fell within the range of soft clays,while that of unsaturated specimen lies within the range of UGMs.展开更多
Nanoscale red phosphorus(NRP)was synthesized via a phosphorus-amine dissolution method and immobilized onto mesoporous silica nanospheres(MSNs)to obtain hybrid NRP@MSN particles with improved dispersion stability.Epox...Nanoscale red phosphorus(NRP)was synthesized via a phosphorus-amine dissolution method and immobilized onto mesoporous silica nanospheres(MSNs)to obtain hybrid NRP@MSN particles with improved dispersion stability.Epoxy resin(EP)composites containing 2 wt%fillers were prepared to evaluate their thermal and flame-retardant behaviors.Compared with EP,the NRP@MSNs/EP composite significantly enhanced fire safety,resulting in a 52.8%reduction in the peak heat release rate,a 13.9%decrease in total smoke production,and a 165%increase in char yield.Mechanical testing revealed a notable toughening effect under impact loading.The improved flame retardancy originates from the combined nano-barrier effect of MSNs and the catalytic charring and radical-quenching functions of NRP.This work demonstrates an efficient strategy for stabilizing NRP and highlights its strong potential as an environmentally friendly flame retardant for EP systems.展开更多
Optimization is the key to obtaining efficient utilization of resources in structural design.Due to the complex nature of truss systems,this study presents a method based on metaheuristic modelling that minimises stru...Optimization is the key to obtaining efficient utilization of resources in structural design.Due to the complex nature of truss systems,this study presents a method based on metaheuristic modelling that minimises structural weight under stress and frequency constraints.Two new algorithms,the Red Kite Optimization Algorithm(ROA)and Secretary Bird Optimization Algorithm(SBOA),are utilized on five benchmark trusses with 10,18,37,72,and 200-bar trusses.Both algorithms are evaluated against benchmarks in the literature.The results indicate that SBOA always reaches a lighter optimal.Designs with reducing structural weight ranging from 0.02%to 0.15%compared to ROA,and up to 6%–8%as compared to conventional algorithms.In addition,SBOA can achieve 15%–20%faster convergence speed and 10%–18%reduction in computational time with a smaller standard deviation over independent runs,which demonstrates its robustness and reliability.It is indicated that the adaptive exploration mechanism of SBOA,especially its Levy flight–based search strategy,can obviously improve optimization performance for low-and high-dimensional trusses.The research has implications in the context of promoting bio-inspired optimization techniques by demonstrating the viability of SBOA,a reliable model for large-scale structural design that provides significant enhancements in performance and convergence behavior.展开更多
Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream...Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream of Red Mansions and All Men Are Brothers,two masterpieces of Chinese classical literature,have long been central to debates regarding the authorship of their later chapters.Previous studies,often based on word-frequency statistics,function word distributions,entropy measures,and complex network analyses,have provided valuable insights into stylistic differences;however,they remain limited in capturing cross-scale structural features.To address this gap,we apply a multi-scale structural complexity approach based on character-frequency time series to analyze the structural evolution of both novels under various segmentation strategies.Our results reveal significant differences in peak complexity positions,overall complexity levels,and intra-textual variations between the two works,which are closely linked to changes in authorship and stylistic patterns.This study not only provides new quantitative evidence for resolving authorship disputes in classical literature but also demonstrates,from the perspective of structural complexity,the profound depth and unique charm of Chinese literary expression,highlighting the richness of Chinese language and culture.Moreover,it emphasizes the potential of structural complexity analysis as a versatile tool for textual analysis and style attribution.展开更多
The contribution rate of ecosystem service value variation was used to analyze the effects of land use changes on the changes of ecosystem service value in Xingguo County during 1996-2005.Grey integrated correlation w...The contribution rate of ecosystem service value variation was used to analyze the effects of land use changes on the changes of ecosystem service value in Xingguo County during 1996-2005.Grey integrated correlation was employed to explore the contribution level of the indicators such as total population,urbanization level,proportion of primary industry and investment of social fixed assets on ecosystem service value,and the correlation analysis was also carried out.The results showed that the ecosystem service value in Xingguo County during 1996-2005 mainly was woodland,and the decrease of woodland area was the major reason for the sustained reduction of ecosystem service value.With the further increase of market demand and the incentives of local government,the garden area rapidly increased during 2001-2005,and the influence degree of garden towards the changes of ecosystem service value was only second to woodland,ranking No.2.Four socio-economic indicators had different correlation degree with ecosystem service value during the different research periods.Total population,urbanization level and proportion of primary industry had high correlation degree with ecosystem service value,whereas the influence degree of various socio-economic indicators on ecosystem service value was equal with each other day by day.Urbanization level,investment of social fixed assets and total population had significant negative correlation with ecosystem service value,while the proportion of primary industry had positive correlation with ecosystem service value.展开更多
The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of south...The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br).The ability of different vegetation systems to conserve soil and water was in the order of Ctr ＞ BP ＞ CF ＞ FL ＞ Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP,TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers.However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously.展开更多
The current recovery technique of Sc was complicated and the chemical consumption was high,This was due to the low content of Sc in resources and the difficulty of stripping.In this research,the isooctanol was added i...The current recovery technique of Sc was complicated and the chemical consumption was high,This was due to the low content of Sc in resources and the difficulty of stripping.In this research,the isooctanol was added into the 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester(P507)extraction system to reduce the extraction and improve the stripping of Sc.The maximum stripping ratio of Sc from loaded organic phase by sulfuric acid can increase from 10%(without isooctanol)to 99%(with 15 vol%isooctanol).In the extraction test of the simulated red mud leaching liquor,the separation factors between Sc and Zr,Sc and Ti are 36 and 350,separately.At the same time,other metals are almost not extracted.The high selectivity and stripping of Sc suggest that the P507 with isooctanol extraction system can be applied in the practical Sc recovery process.展开更多
AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, ...AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, Web of Science and Cochrane Library databases to identify clinical studies, followed by using STATA version 12.0 for statistical analysis. Studies that met the following criteria were considered eligible:(1) Studies including EC patients who underwent radical esophagectomy;(2) studies including patients with localized disease without distant metastasis;(3) studies including patients without preoperative neoadjuvant therapy;(4) studies including patients without previous antiinflammatory therapies and with available preoperative laboratory outcomes;(5) studies reporting association between the preoperative RDW and overall survival(OS)/disease-free survival(DFS)/cancer-specific survival(CSS); and(6) studies published in English.RESULTS A total of six articles, published between 2015 and 2017, fulfilled the selection criteria in the end. Statistical analysis showed that RDW was not associated with the prognosis of EC patients, irrespective of OS/CSS [hazard ratio(HR) = 1.27, 95% confidence interval(CI): 0.97-1.57, P = 0.000] or DFS(HR = 1.42, 95%CI: 0.96-1.88, P = 0.000). Subgroup analysis indicated that elevated RDW was significantly associated with worse OS/CSS of EC patients when RDW > 13%(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000), when the patient number ≤ 400(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000) and when the study type was retrospective(HR = 1.42, 95%CI : 1.16-1.69, P = 0.000).CONCLUSION Contrary to our general understanding, this meta-analysis revealed that RDW cannot serve as an indicator of poor prognosis in patients with EC. However, it may still be a useful predictor of unfavorable prognosis using an appropriate cut-off value.展开更多
In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evalu...In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized.展开更多
An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological ExperimentStation of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28° 15′ 30″ N, 116° 55′ 30...An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological ExperimentStation of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28° 15′ 30″ N, 116° 55′ 30″E), Jiangxi Province. The results show that the major ways of nutrient loss are leaching and nitrogenvolatilization. Rationalizing crop distribution, stimulating nutrient recycling, and improving internal nutrientflow are effective measures to decrease nutrient loss and to promote nutrient utilization efficiency. Theimportant ways of regulating nutrient cycling and balance in the agroecosystem of the red soil are to establishoptimal eco-agricultural models, practice balanced fertilization and combine the cropping system with thelivestock system.展开更多
This study on the distribution of phosphate and its relation to phytoplankton biomass in Western Xiamen Harbor using marine ecosystem enclosures to isolate the culture water from the tidal currents and salinity change...This study on the distribution of phosphate and its relation to phytoplankton biomass in Western Xiamen Harbor using marine ecosystem enclosures to isolate the culture water from the tidal currents and salinity changes outside indicated that the phytoplankton biomass variation closely related to dissolved inorganic phosphorus (DIP) in the seawater as described by the equation: [Chl a]=A×e -B[PO4] . The biomass changes lagged by about two days the corresponding DIP. The research also dealt with the minimal DIP concentration for stopping diatom bloom and the possible maximal diatom biomass was estimated from the DIP external concentration in the seawater. The threshold of DIP initiating Skeletonema costatum red tide was calculated for use as an index to forecast its red tides. In addition, the relationships between a dinoflagellate red tide and nutrients are discussed. The results showed that the multiplication of dinoflagellate was not entirely dependent on the nutrients in the seawater.展开更多
A series of enclosed ecosystem experiments were conducted in a land based tank near the seaside of West Xiamen Harbor.The results of experiments conducted in different seasons and years showed a repeatble phytoplankto...A series of enclosed ecosystem experiments were conducted in a land based tank near the seaside of West Xiamen Harbor.The results of experiments conducted in different seasons and years showed a repeatble phytoplankton succession. In this relatively stable ecosystem with added nutrients and trace metals,diatoms dominated initially,dinoflagellates dominated in the later stage,and dinoflagellate red tides eventually occurred.Vitamin B 12 enrichment may speed up this succession process. Stirring the water column could stop this process. Soluble Mn at a level of 3-4 μg/L in seawater,which also is the existing concentration of solu ble Mn in Xiamen Harbor seawater,is sufficient for the multiplication of algae and occurrence of red tide.The present study showed that excessive soluble Mn in Xiamen Harbor cannot cause red tide,and that Fe was one of the important factors causing diatom red tide in this present study..展开更多
Red soil is a very important soil resource in southern China. However, due to being simultaneously of high productive potentialities and severely degraded, it needs harnessing urgently. Red Soil Resource Information S...Red soil is a very important soil resource in southern China. However, due to being simultaneously of high productive potentialities and severely degraded, it needs harnessing urgently. Red Soil Resource Information System (RSRIS) based on remote sensing and geographic information system (GIS) plays an important role in survey, evaluation, utilization and management of red soil resource. RSRIS of Quzhou City) Zhejiang Province (1:250000) and RSRIS of Longyou County, Zhejiang Province (1:50000) have been made respectively on SUN SPARC station and using ARC/INFO. This paper introduces the system design,database creation and system functions, and it particularly focuses on developing applied models, such as red soil resource division and mapping, suitability evaluation, erosion risk evaluation, plant utilization zone etc. The problems on study of RSRIS and its developing strategy are also discussed.展开更多
文摘Objective Analyzing the nonlinear dynamics of the TCP-RED congestion control system is of great importance. This study will help investigate the loss of stability in Internet and design a proper method for controlling bifurcation and chaos in such system. Methods Based on bifurcation diagram, the effect of parameter on system performance is discussed. By using the state feedback and parameter variation strategy, a simple real time control method is proposed to modify the existing RED scheme. Results With our control method, the parametric sensitivity of RED mechanism is attenuated. Moreover, a sufficient condition on the robust stability of the system is also derived to adjust the parameters in TCP-RED system. Conclusion The proposed method has the advantages of simple implementation and unnecessary knowledge of the exact system.
基金the financial support from the National Key R&D Program of China(No.2022YFC2904405)the National Natural Science Foundation of China(Nos.22078055,51774079)。
文摘To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM methods,and a novel hydrothermal process based on the conversion principle was finally proposed.The crystal structure simulation shows that the HA with varied silicon saturation coefficients is more stable than HG,and the HA with a high iron substitution coefficient is more difficult to be converted from HG.The(110)plane of Fe_(2)O_(3) is easier to combine with HG to form HA,and the binding energy is 81.93 kJ/mol.The effects of raw material ratio,solution concentration and hydrothermal parameters on the conversion from HG to HA were revealed,and the optimal conditions for the alumina recovery were obtained.The recovery efficiencies of alumina and Na_(2)O from the RM are 63.06%and 97.34%,respectively,and the Na_(2)O content in the treated RM is only 0.13%.
基金supported by the Key R&D Program of Shaanxi Province,China(2024NC-YBXM-146)the Xi’an Agricultural Technology Research and Development Project,China(24NYGG0048)+1 种基金the Key R&D Program of Xianyang,China(L2024-ZDYF-ZDYF-NY-0028)the National Foreign Expert Project of China(G2023172002L)。
文摘The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.
基金Supported by the Humanities and Social Science Research Project of Jiangxi Provincial Universities(YS23104).
文摘In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.
基金Funded by the Shandong Province Key R&D Program(Major Technological Innovation Project(Nos.2023ZLGX01 and 2021CXGC010301)the Youth Project of National Natural Science Foundation(No.52309136)+1 种基金the Competitive Innovation Platform Project of Shandong Province(No.2023CXPT-080)the Postdoctoral Innovation Project(No.SDCX-ZG-202203037)。
文摘To improve the applicability of red mud in subgrade construction,we studied the effects of four traditional retarders,including borax,sodium hexametaphosphate,sodium gluconate,and sucrose,on the setting time,mechanical properties and soil solidification of red mud-based subgrade engineered cementitious material(RCM).The mechanisms of the retarders on the hydration process of RCM were analyzed by hydration microcalorimeter,XRD,TG,and SEM-EDS.The experimental results show that four retarders have retarding effect on RCM,among which sodium gluconate and sucrose have significant retarding effect and do not have adverse effect on 28 d strength.Borax can slightly delay the setting time,and sodium hexametaphosphate has a better retarding effect,but they both reduce the 28 d strength.Microcosmic analysis shows that the retarders do not change the type of RCM hydration products,but mainly slow down the rate of hydration reaction through the adsorption and complexation or reaction of Ca^(2+)in the slurry.All the results show that the retarder has no weakening effect on the unconfined compressive strength,water stability and CBR properties of the stabilized subgrade soil based on RCM.
基金support of the ORG.one project of Oxford Nanopore Technologies(ONT),the Rufford Grants(45249-1)the Idea Wild Grants(Project ID-KJOSINDI0125-00)the Mohamed Bin Zyed Species Conservation(MBZ)(GEF Grant no-240535253)Funds in our efforts to conserve threatened trees in the Western Ghats Biodiversity Hotspot Forest regions.
文摘Plants constitute nearly 80%of the planet’s total biomass(Bar-On et al.,2018);however,this vital group is experiencing severe threats,and recent evaluations indicate that approximately 45%of the world's described plant species are at risk of extinction(Bachman et al.,2024).The number of plant extinctions has increased by 60%in the last 100 years(Di Marco et al.,2017).Over the past 250 years,571 plant species have gone extinct—more than twice the combined total of extinct birds,mammals,and amphibians(217 species)(Briggs,2019).
基金support from the National Natural Science Foundation of China(Grant Nos.52278432 and 52478475)the Science and Technology Research and Development Plan of China National Railway Group Co.,Ltd.(Grant No.K2023G033)were greatly appreciated.
文摘Understanding the shakedown behavior of fill material is paramount to estimate the deformation stability of railway subgrade.Especially for red mudstone fill material(RMF),the noticeable overestimation of bearing capacity would be encountered if the conventional strength method is used.This paper presents the shakedown analysis on RMF,with a specific emphasis on the effect of water content.A series of cyclic triaxial tests with 50,000 loading cycles was conducted.Two-stage behavior of permanent deformation and dissipated energy responses was clearly characterized,from which an energy-based criterion was proposed to determine the shakedown limits.The proposed energy-based criterion was validated by examining its performance to various geomaterials including cohesive soils and unbound granular materials(UGMs).By applying the proposed method to RMF,the S-shape evolution curve was obtained in terms of shakedown limits with initial suction.Microfabric difference was believed as the main consequence of the S-shape mode.Demonstration was confirmed by the mercury intrusion porosimetry(MIP)and scanning electron microscope(SEM)analyses.By applying the proposed method to different geomaterials,an extensive comparison was made between the shakedown limits and the static shear strength.The ratio of shakedown limits to the static shear strength for saturated RMF specimen fell within the range of soft clays,while that of unsaturated specimen lies within the range of UGMs.
基金financially supported by the National Natural Science Foundation of China(Nos.22175167 and 22375195)the Science Fund for Distinguished Young Scholars of Anhui Province(No.2308085J05)This work was also partially carried out at the Instruments Center for Physical Science,University of Science and Technology of China,and partially performed using the services from Scientific Compass(www.shiyanjia.com).
文摘Nanoscale red phosphorus(NRP)was synthesized via a phosphorus-amine dissolution method and immobilized onto mesoporous silica nanospheres(MSNs)to obtain hybrid NRP@MSN particles with improved dispersion stability.Epoxy resin(EP)composites containing 2 wt%fillers were prepared to evaluate their thermal and flame-retardant behaviors.Compared with EP,the NRP@MSNs/EP composite significantly enhanced fire safety,resulting in a 52.8%reduction in the peak heat release rate,a 13.9%decrease in total smoke production,and a 165%increase in char yield.Mechanical testing revealed a notable toughening effect under impact loading.The improved flame retardancy originates from the combined nano-barrier effect of MSNs and the catalytic charring and radical-quenching functions of NRP.This work demonstrates an efficient strategy for stabilizing NRP and highlights its strong potential as an environmentally friendly flame retardant for EP systems.
文摘Optimization is the key to obtaining efficient utilization of resources in structural design.Due to the complex nature of truss systems,this study presents a method based on metaheuristic modelling that minimises structural weight under stress and frequency constraints.Two new algorithms,the Red Kite Optimization Algorithm(ROA)and Secretary Bird Optimization Algorithm(SBOA),are utilized on five benchmark trusses with 10,18,37,72,and 200-bar trusses.Both algorithms are evaluated against benchmarks in the literature.The results indicate that SBOA always reaches a lighter optimal.Designs with reducing structural weight ranging from 0.02%to 0.15%compared to ROA,and up to 6%–8%as compared to conventional algorithms.In addition,SBOA can achieve 15%–20%faster convergence speed and 10%–18%reduction in computational time with a smaller standard deviation over independent runs,which demonstrates its robustness and reliability.It is indicated that the adaptive exploration mechanism of SBOA,especially its Levy flight–based search strategy,can obviously improve optimization performance for low-and high-dimensional trusses.The research has implications in the context of promoting bio-inspired optimization techniques by demonstrating the viability of SBOA,a reliable model for large-scale structural design that provides significant enhancements in performance and convergence behavior.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275179,11875042,and12150410309)the Natural Science Foundation of Shanghai(Grant No.21ZR1443900)。
文摘Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream of Red Mansions and All Men Are Brothers,two masterpieces of Chinese classical literature,have long been central to debates regarding the authorship of their later chapters.Previous studies,often based on word-frequency statistics,function word distributions,entropy measures,and complex network analyses,have provided valuable insights into stylistic differences;however,they remain limited in capturing cross-scale structural features.To address this gap,we apply a multi-scale structural complexity approach based on character-frequency time series to analyze the structural evolution of both novels under various segmentation strategies.Our results reveal significant differences in peak complexity positions,overall complexity levels,and intra-textual variations between the two works,which are closely linked to changes in authorship and stylistic patterns.This study not only provides new quantitative evidence for resolving authorship disputes in classical literature but also demonstrates,from the perspective of structural complexity,the profound depth and unique charm of Chinese literary expression,highlighting the richness of Chinese language and culture.Moreover,it emphasizes the potential of structural complexity analysis as a versatile tool for textual analysis and style attribution.
基金Supported by Natural Science Foundation of Jiangxi Province"Research on Optimization Model of Land Use in Southern Hilly Region with Red Soil in Jiangxi Province based on Ecological Security Evaluation"(2008GQH0057)Educational Commission of Jiangxi Province"Research on Scenario Simulation of Land Use Security Pattern in Southern Hilly Region with Red Soil in Jiangxi Province" (GJJ09557)Innovative Experimental Projects of National University Students"Research on Land Use Ecological Security Assessment in Hilly Region with Red Soil based on GIS-Xingguo County in Jiangxi Province as an Example"(101042124)~~
文摘The contribution rate of ecosystem service value variation was used to analyze the effects of land use changes on the changes of ecosystem service value in Xingguo County during 1996-2005.Grey integrated correlation was employed to explore the contribution level of the indicators such as total population,urbanization level,proportion of primary industry and investment of social fixed assets on ecosystem service value,and the correlation analysis was also carried out.The results showed that the ecosystem service value in Xingguo County during 1996-2005 mainly was woodland,and the decrease of woodland area was the major reason for the sustained reduction of ecosystem service value.With the further increase of market demand and the incentives of local government,the garden area rapidly increased during 2001-2005,and the influence degree of garden towards the changes of ecosystem service value was only second to woodland,ranking No.2.Four socio-economic indicators had different correlation degree with ecosystem service value during the different research periods.Total population,urbanization level and proportion of primary industry had high correlation degree with ecosystem service value,whereas the influence degree of various socio-economic indicators on ecosystem service value was equal with each other day by day.Urbanization level,investment of social fixed assets and total population had significant negative correlation with ecosystem service value,while the proportion of primary industry had positive correlation with ecosystem service value.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No.2002CB410807).
文摘The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br).The ability of different vegetation systems to conserve soil and water was in the order of Ctr ＞ BP ＞ CF ＞ FL ＞ Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP,TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers.However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously.
基金Project supported by the National Basic Research Program of China(2012CBA01202)the National Natural Science Foundation of China(51174184)
文摘The current recovery technique of Sc was complicated and the chemical consumption was high,This was due to the low content of Sc in resources and the difficulty of stripping.In this research,the isooctanol was added into the 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester(P507)extraction system to reduce the extraction and improve the stripping of Sc.The maximum stripping ratio of Sc from loaded organic phase by sulfuric acid can increase from 10%(without isooctanol)to 99%(with 15 vol%isooctanol).In the extraction test of the simulated red mud leaching liquor,the separation factors between Sc and Zr,Sc and Ti are 36 and 350,separately.At the same time,other metals are almost not extracted.The high selectivity and stripping of Sc suggest that the P507 with isooctanol extraction system can be applied in the practical Sc recovery process.
基金Supported by CAMS Innovation Fund for Medical Science(CIFMS),No.2017-12M-4-003International Science and technology Cooperation Projects,No.2015DFA30650 and No.2016yFE0107100+1 种基金Capital Special Research Project for Health Development,No.2014-2-4012Beijing Natural Science Foundation,No.L172055
文摘AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, Web of Science and Cochrane Library databases to identify clinical studies, followed by using STATA version 12.0 for statistical analysis. Studies that met the following criteria were considered eligible:(1) Studies including EC patients who underwent radical esophagectomy;(2) studies including patients with localized disease without distant metastasis;(3) studies including patients without preoperative neoadjuvant therapy;(4) studies including patients without previous antiinflammatory therapies and with available preoperative laboratory outcomes;(5) studies reporting association between the preoperative RDW and overall survival(OS)/disease-free survival(DFS)/cancer-specific survival(CSS); and(6) studies published in English.RESULTS A total of six articles, published between 2015 and 2017, fulfilled the selection criteria in the end. Statistical analysis showed that RDW was not associated with the prognosis of EC patients, irrespective of OS/CSS [hazard ratio(HR) = 1.27, 95% confidence interval(CI): 0.97-1.57, P = 0.000] or DFS(HR = 1.42, 95%CI: 0.96-1.88, P = 0.000). Subgroup analysis indicated that elevated RDW was significantly associated with worse OS/CSS of EC patients when RDW > 13%(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000), when the patient number ≤ 400(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000) and when the study type was retrospective(HR = 1.42, 95%CI : 1.16-1.69, P = 0.000).CONCLUSION Contrary to our general understanding, this meta-analysis revealed that RDW cannot serve as an indicator of poor prognosis in patients with EC. However, it may still be a useful predictor of unfavorable prognosis using an appropriate cut-off value.
文摘In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized.
文摘An experiment was conducted in a red soil derived from Quaternary red clay in the Ecological ExperimentStation of Red Soil, the Chinese Academy of Sciences, located in Yingtan (28° 15′ 30″ N, 116° 55′ 30″E), Jiangxi Province. The results show that the major ways of nutrient loss are leaching and nitrogenvolatilization. Rationalizing crop distribution, stimulating nutrient recycling, and improving internal nutrientflow are effective measures to decrease nutrient loss and to promote nutrient utilization efficiency. Theimportant ways of regulating nutrient cycling and balance in the agroecosystem of the red soil are to establishoptimal eco-agricultural models, practice balanced fertilization and combine the cropping system with thelivestock system.
文摘This study on the distribution of phosphate and its relation to phytoplankton biomass in Western Xiamen Harbor using marine ecosystem enclosures to isolate the culture water from the tidal currents and salinity changes outside indicated that the phytoplankton biomass variation closely related to dissolved inorganic phosphorus (DIP) in the seawater as described by the equation: [Chl a]=A×e -B[PO4] . The biomass changes lagged by about two days the corresponding DIP. The research also dealt with the minimal DIP concentration for stopping diatom bloom and the possible maximal diatom biomass was estimated from the DIP external concentration in the seawater. The threshold of DIP initiating Skeletonema costatum red tide was calculated for use as an index to forecast its red tides. In addition, the relationships between a dinoflagellate red tide and nutrients are discussed. The results showed that the multiplication of dinoflagellate was not entirely dependent on the nutrients in the seawater.
文摘A series of enclosed ecosystem experiments were conducted in a land based tank near the seaside of West Xiamen Harbor.The results of experiments conducted in different seasons and years showed a repeatble phytoplankton succession. In this relatively stable ecosystem with added nutrients and trace metals,diatoms dominated initially,dinoflagellates dominated in the later stage,and dinoflagellate red tides eventually occurred.Vitamin B 12 enrichment may speed up this succession process. Stirring the water column could stop this process. Soluble Mn at a level of 3-4 μg/L in seawater,which also is the existing concentration of solu ble Mn in Xiamen Harbor seawater,is sufficient for the multiplication of algae and occurrence of red tide.The present study showed that excessive soluble Mn in Xiamen Harbor cannot cause red tide,and that Fe was one of the important factors causing diatom red tide in this present study..
文摘Red soil is a very important soil resource in southern China. However, due to being simultaneously of high productive potentialities and severely degraded, it needs harnessing urgently. Red Soil Resource Information System (RSRIS) based on remote sensing and geographic information system (GIS) plays an important role in survey, evaluation, utilization and management of red soil resource. RSRIS of Quzhou City) Zhejiang Province (1:250000) and RSRIS of Longyou County, Zhejiang Province (1:50000) have been made respectively on SUN SPARC station and using ARC/INFO. This paper introduces the system design,database creation and system functions, and it particularly focuses on developing applied models, such as red soil resource division and mapping, suitability evaluation, erosion risk evaluation, plant utilization zone etc. The problems on study of RSRIS and its developing strategy are also discussed.
