El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and de...El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate.展开更多
BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a pauci...BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese population.AIM To quantify the natural tumor growth pattern of HCC in regional China.METHODS A retrospective analysis was performed on patients from a single institution in Southwest China who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer therapy.Tumor growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced radiologists.Simple univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical factors.RESULTS This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 months.CONCLUSION The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of China.Given the observed heterogeneity in HCC growth,further investigation is warranted.展开更多
It is known that injection of carbon dioxide into the petroleum reservoir(CO_(2) flooding) is one of the effective methods for enhanced oil recovery. CO_(2) flooding may be complicated by formation of CO_(2) hydrate p...It is known that injection of carbon dioxide into the petroleum reservoir(CO_(2) flooding) is one of the effective methods for enhanced oil recovery. CO_(2) flooding may be complicated by formation of CO_(2) hydrate plugs. It makes topical investigation of CO_(2) hydrate formation in the system gaseous CO_(2)-oil-water. In this work, the growth rates of carbon dioxide hydrate films at the water-oil as well as the water-gas interface are studied in the pressure range of 2.30-3.04 MPa and at temperatures between -5.4 and 5.0℃. It is found that the growth rate for the water-oil interface is 3.5 times lower than that for the water-gas interface with carbon dioxide. It is hypothesised that the observed decrease in the growth rate is related to the mechanical resistance of the oil components adsorbed on the interface to the growth of the hydrate film. The growth rate of the film has been shown to depend on the experimental procedure,most likely due to the different initial concentrations of carbon dioxide in the aqueous solutions.展开更多
Inventory data were available from 96 plots of even-aged,monoculture,tall-open forests of Eucalyptus pilularis Smith,aged 2-63 years,growing in sub-tropical regions along the east coast of Australia.A model was develo...Inventory data were available from 96 plots of even-aged,monoculture,tall-open forests of Eucalyptus pilularis Smith,aged 2-63 years,growing in sub-tropical regions along the east coast of Australia.A model was developed relating the maximum possible stem basal area growth rate of individual trees to their stem basal area.For any tree size,this maximum increased as site productivity increased.However,the size at which this maximum occurred decreased as productivity increased.Much research has shown that,at any stand age,trees of a particular stem basal area are taller on more productive sites than on less productive ones.Taller trees incur greater respiratory costs to ensure maintenance of the photo synthetic capacity of their canopies;this reduces their growth rates.It was concluded that trees with larger basal areas will have the maximum possible growth rate on a less productive site,whilst trees with smaller basal areas will have the maximum possible on a more productive site.The model developed may constitute the first stage of a complete individual tree growth model system to predict wood yields from these forests.展开更多
Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of ...Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of growth-related genes in zebrafish and MC3T3-E1 cells were assessed using various molecular techniques.Furthermore,the involvement of the mammalian target of rapamycin(mTOR)pathway in AEPB-induced growth was investigated by employing the mTOR inhibitor rapamycin.Results:AEPB administration led to a significant and dose-dependent increase in zebrafish larvae growth over time.Additionally,AEPB treatment upregulated the expression of growth hormone-1(GH-1),insulin-like growth factor-1(IGF-1),growth hormone receptor-1(GHR-1),and cholecystokinin-a(CCKA)in zebrafish.Similarly,AEPB stimulated the expression and release of IGF-1 and accelerated mTOR expression in MC3T3-E1 cells.In addition,rapamycin hindered AEPB-induced linear growth in zebrafish larvae and suppressed the expression of growth-promoting genes by inhibiting mTOR activation.Conclusions:AEPB shows growth-promoting effects by upregulating growth-related genes and activating the mTOR signaling pathway.Further investigations are warranted to elucidate its mechanisms of action and explore its potential application in the development of growth-enhancing supplements for various purposes.展开更多
Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesiu...Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth.展开更多
Experimental study is performed on the probabilistic models for the long fatigue crack growth rates (da/dN) of LZ50 axle steel. An equation for crack growth rate was derived to consider the trend of stress intensity...Experimental study is performed on the probabilistic models for the long fatigue crack growth rates (da/dN) of LZ50 axle steel. An equation for crack growth rate was derived to consider the trend of stress intensity factor range going down to the threshold and the average stress effect. The probabilistic models were presented on the equation. They consist of the probabilistic da/dN-△K relations, the confidence-based da/dN-△K relations, and the probabilistic- and confidence-based da/dN-△K relations. Efforts were made respectively to characterize the effects of probabilistic assessments due to the scattering regularity of test data, the number of sampling, and both of them. These relations can provide wide selections for practice. Analysis on the test data of LZ50 steel indicates that the present models are available and feasible.展开更多
The growth rates of bainite plates in an Fe-C-Mn-Si superbainitie steel were investigated by in situ observation. The lengthening rates of ferrite bainite during both cooling and isothermal holding processes were obse...The growth rates of bainite plates in an Fe-C-Mn-Si superbainitie steel were investigated by in situ observation. The lengthening rates of ferrite bainite during both cooling and isothermal holding processes were observed and the growth rates of bainite plates nucleating at grain boundaries, within grains and on preformed bainite were measured. It is indicated that the lengthening rates of bainite plates during the cooling and isothermal processes were different, and that the growth rates of bainite plates nucleating at different types of sites also demon- strated diversity. The bainite plates initiating at [vain boundaries during cooling grew the fastest, while the plates nucleating on preformed bainite did the slowest. However, the growth rate of the bainite plates nucleating at grain boundaries during isothermal transformation de- creased the most, whereas the bainite plates initiating within grains grew the fastest. In addition, the growth rate of ferrite bainite in the study supported the diffusion transformation mechanism of bainite from the viewooint of ~rowth rate.展开更多
Tree competitiveness generally depends on trait plasticity in response to environmental change.The effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’...Tree competitiveness generally depends on trait plasticity in response to environmental change.The effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’s subtropical forests.This study examined the seedling leaf traits and net primary productivity of all trees>5 cm DBH of two dominant species,Schima superba and Castanopsis carlesii,in an evergreen broadleaved forest fertilized with nitrogen(+N),phosphorus(+P),and nitrogen plus phosphorus(N+P).The effect of N on seedling leaf traits was stronger than P,while fertilization in general was species dependent.Leaf mass per unit area decreased with N for S.superba seedlings but not for C.carlesii.Leaf N,P,and N/P ratios changed with N addition for both species.All four N fractions of carboxylation,bioenergetics,cell wall,and other N metabolites in C.carlesii leaves responded significantly to fertilization,while only the cell wall in S.superb a leaves responded.Other leaf functional traits,including light-saturated photosynthetic rates,water,N,and P use efficiencies,chlorophyll and non structural carbohydrate contents increased with N addition in S.superb a and by P addition in C.carlesii.Canopy closure at the stand-level increased due to N.Litter biomass and relative growth rate of S.superb a was not affected by any treatments,while both for C.carlesii significantly decreased with N+P addition.Collectively,nutrient limitation may vary at a small scale among species in a subtropical forest based on their responses of seedling traits and net primary productivity to fertilization.Seedling traits are not correlated with the net primary productivity of larger trees except for N fractions,because low light conditions induced by fertilization reduces the proportion of N allocated to photosynthesis in seedlings.In addition,acclimation differences of tree species may increase the uncertainty of community succession.展开更多
Three types of fatigue tests for an annealed carbon steel containing carbon of 0.42%were carried out on smooth specimens and specimens with a small blind hole in order to investigate the fatigue crack growth law.A sim...Three types of fatigue tests for an annealed carbon steel containing carbon of 0.42%were carried out on smooth specimens and specimens with a small blind hole in order to investigate the fatigue crack growth law.A simple predicting method for crack growth rates has been proposed involving strengthσband the relation between cyclic stress and strain.The validity of proposed method has been confirmed by experiments on several carbon steels with different loadings.展开更多
Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suita...Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.展开更多
Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are diffi...Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are difficult to apply in engineering practice.Symbolic regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for datasets.In this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate model.Three terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate models.Based on the FCG rate test data from other literature,the SR model was constructed using Al-7055-T7511.It was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear regression.Compared with the three semi-empirical FCG rate models,the SR model yielded higher prediction accuracy.This result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.展开更多
The elementary task is to calculate the growth rates of disturbances when the e;method in transition prediction is performed. However, there is no unified knowledge to determine the growth rates of disturbances in thr...The elementary task is to calculate the growth rates of disturbances when the e;method in transition prediction is performed. However, there is no unified knowledge to determine the growth rates of disturbances in three-dimensional(3 D) flows. In this paper, we study the relation among the wave parameters of the disturbance in boundary layers in which the imaginary parts of wave parameters are far smaller than the real parts.The generalized growth rate(GGR) in the direction of group velocity is introduced, and the conservation relation of GGR is strictly deduced in theory. This conservation relation manifests that the GGR only depends on the real parts of wave parameters instead of the imaginary parts. Numerical validations for GGR conservation are also provided in the cases of first/second modes and crossflow modes. The application of GGR to the eN method in 3 D flows is discussed, and the puzzle of determining growth rates in 3 D flows is clarified. A convenient method is also proposed to calculate growth rates of disturbances in 3 D flows. Good agreement between this convenient method and existing methods is found except the condition that the angle between the group velocity direction and the x-direction is close to 90?which can be easily avoided in practical application.展开更多
Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and ...Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and duration of their formation are sparse, mainly due to the difficulties extracting datable minerals suited to traditional radiometric dating methods. Hollandite, cryptomelane, coronadite, todorokite, and manjiroite are common manganese oxide minerals in supergene environments. These minerals host potassium of variable amounts from 0.1 wt% to 5.0 wt% in their structural sites. This geochemical property provides possibility to date supergene manganese ores by using K-Ar and 40Ar/ 39Ar methods. In this study, we perform 40Ar/ 39Ar dating on a 7.1-cm-thick botryoidal manganese nodule from an ancient weathering profile at Mount Tabor, central Queensland, Australia. Laser microprobe incremental analyses of distinct growth bands, from the inner core through the intermediate bands to the outermost crusts of the nodule, have yielded high quality 40Ar/ 39Ar ages at 27.3 Ma, 20.9 Ma, 19.2 Ma, and 16.1 Ma, respectively. The age results permit preliminary estimates on the average growth rates of the nodule varying from 4.7×10 -3 mm/ka to 7.6×10 -3 mm/ka to 9.0×10 -3 mm/ka, from the core to the rim. Results of this study are of significance in our understanding of the mode, mechanism, process, and climatic conditions in the formation of supergene manganese ore deposits.展开更多
Growth of fine aerosol particles is investigated during the Aerosol-CCN-Cloud Closure Experiment campaign in June 2013 at an urban site near Beijing. Analyses show a high frequency (- 50%) of fine aerosol particle g...Growth of fine aerosol particles is investigated during the Aerosol-CCN-Cloud Closure Experiment campaign in June 2013 at an urban site near Beijing. Analyses show a high frequency (- 50%) of fine aerosol particle growth events, and show that the growth rates range from 2.1 to 6.5 nm h-1 with a mean value of - 5.1 nm h-1. A review of previous studies indicates that at least four mechanisms can affect the growth of fine aerosol particles: vapor condensation, intramodal coagulation, extramodal coagulation, and multi-phase chemical reaction. At the initial stage of fine aerosol particle growth, condensational growth usually plays a major role and coagulation efficiency generally increases with particle sizes. An overview of previous studies shows higher growth rates over megacity, urban and boreal forest regions than over rural and oceanic regions. This is most likely due to the higher condensational vapor, which can cause strong condensational growth of fine aerosol particles. Associated with these multiple factors of influence, there are large uncertainties for the aerosol particle growth rates, even at the same location.展开更多
Partial sequence of Skeletonema costatum proliferating cell nuclear antigen (PCNA) gene was obtained by reverse transcriptase PCR(RT-PCR) and 3' rapid amplification of cDNA ends (3'-RACE) techniques. Based on ...Partial sequence of Skeletonema costatum proliferating cell nuclear antigen (PCNA) gene was obtained by reverse transcriptase PCR(RT-PCR) and 3' rapid amplification of cDNA ends (3'-RACE) techniques. Based on the obtained PCNA and cytochrome b gene( Cyt b gene) sequences, a real-time fluorescent quantitative PCR (FQ-PCR) method was developed to detect the expression S. costatum PCNA gene, and this method was applied to study the relationship between the growth rate of S. costatum and the average expression amount of PCNA gene in a single cell. The expression amount of PCNA gene had large variation in cells collected at different culture phases, and the trend was well consistent with the growth rate, which suggested that the expression amount of PCNA gene correlated well with the cell division, and the PCNA could be a promising indicator for the S. costatum cell proliferation. Furthermore, using the PCNA gene as the objective gene and the Cyt b gene as the house-keeping gene, a new method for estimating the in situ growth rate of S. costatum was established by analysis of the relative expression quantity (REQ) of the PCNA gene.展开更多
The Monte- Carlo method is used to simulate the surface fatigue crack growth rate for offshore structural steel E36-Z35, and to determine the distributions and relevance of the parameters in the Paris equation. By thi...The Monte- Carlo method is used to simulate the surface fatigue crack growth rate for offshore structural steel E36-Z35, and to determine the distributions and relevance of the parameters in the Paris equation. By this method, the time and cost of fatigue crack propagation testing can be reduced. The application of the method is demonstrated by use of four sets of fatigue crack propagation data for offshore structural steel E36-Z35. A comparison of the test data with the theoretical prediction for surface crack growth rate shows the application of the simulation method to the fatigue crack propagation tests is successful.展开更多
Identifying the main factors on spatial diff erences in net growth rate of Yesso scallop(Patinopecten yessoensis)in culture system is the key to eff ective aquaculture management and development.Coupling a 3D ecosyste...Identifying the main factors on spatial diff erences in net growth rate of Yesso scallop(Patinopecten yessoensis)in culture system is the key to eff ective aquaculture management and development.Coupling a 3D ecosystem model(ROMS-CoSiNE)with a dynamic energy budget model for scallops,a Yesso scallop culture ecosystem(YeSCE)model was established with which scallop growth was simulated with real seeding density and juvenile size from local aquaculture experiments from December 1,2012 to November 30,2013.Results show that the YeSCE model has reasonably simulated the environmental variation and scallop net growth rate in the Changhai sea area.The growth of scallops was slow in winter and midsummer and was limited mainly by temperature.Food availability was a key factor that contributed to the fast growth of the scallops during spring to early summer and in autumn.Generally,the scallops cultured in the north part of the Changhai sea area grew faster than those in the south;and the net growth rate for scallops cultured near the island was signifi cantly higher compare to the others,which is probably correlated to the spatial distribution of food availability.Based on the correlation analysis,the spatial diff erences of the net growth rate were largely aff ected by the length of the match timing of temperatures and food availability.The results of this study provide a scientifi c support for optimizing bottom culture planning and adjusting bottom culture methods.展开更多
The 4.2 ka event that occurred during the period from 4 500–3 900 a BP was characterized by cold and dry climates and resulted in the collapse of civilizations around the world. The cause of this climatic event, howe...The 4.2 ka event that occurred during the period from 4 500–3 900 a BP was characterized by cold and dry climates and resulted in the collapse of civilizations around the world. The cause of this climatic event, however, has been under debate. We collected four corals(Porites lutea) from Yongxing Island, Xisha Islands, South China Sea, dated them with the U-series method, and measured the annual coral growth rates using X-ray technology. The dating results showed that the coral growth ages were from 4 500–3 900 a BP, which coincide well with the period of the4.2 ka event. We then reconstructed annual sea surface temperature anomaly(SSTA) variations based on the coral growth rates. The growth rate-based SSTA results showed that the interdecadal SSTA from 4 500–3 900 a BP was lower than that during modern times(1961–2008 AD). A spectral analysis showed that the SSTA variations from4 500–3 900 a BP were under the influence of El Nino-Southern Oscillation(ENSO) activities. From 4 500–4 100 a BP, the climate exhibited La Nina-like conditions with weak ENSO intensity and relatively stable and lower SSTA amplitudes. From 4 100–3 900 a BP, the climate underwent a complicated period of ENSO variability and showed alternating El Nino-or La Nina-like conditions at interdecadal time scales and large SSTA amplitudes. We speculate that during the early and middle stages of the 4.2 ka event, the cold climate caused by weak ENSO activities largely weakened social productivity. Then, during the end stages of the 4.2 ka event, the repeated fluctuations in the ENSO intensity caused frequent extreme weather events, resulting in the collapse of civilizations worldwide. Thus, the new evidence obtained from our coral records suggests that the 4.2 ka event as well as the related collapse of civilizations were very likely driven by ENSO variability.展开更多
A systematic investigation on PA-MBE grown GaN with low growth rates(less than 0.2μm/h)has been conducted in a wide growth temperature range,in order to guide future growth of sophisticated fine structures for quantu...A systematic investigation on PA-MBE grown GaN with low growth rates(less than 0.2μm/h)has been conducted in a wide growth temperature range,in order to guide future growth of sophisticated fine structures for quantum device applications.Similar to usual growths with higher growth rates,three growth regions have been revealed,namely,Ga droplets,slightly Ga-rich and N-rich 3D growth regions.The slightly Ga-rich region is preferred,in which GaN epilayers demonstrate optimal crystalline quality,which has been demonstrated by streaky RHEED patterns,atomic smooth surface morphology,and very low defect related yellow and blue luminescence bands.The growth temperature is a critical parameter to obtain high quality materials and the optimal growth temperature window(~700-760℃)has been identified.The growth rate shows a strong dependence on growth temperatures in the optimal temperature window,and attention must be paid when growing fine structures at a low growth rate.Mg and Si doped GaN were also studied,and both p-and n-type materials were obtained.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 42192564)Guangdong Major Project of Basic and Applied Basic Research (Grant No. 2020B0301030004)the Ministry of Science and Technology of the People's Republic of China (Grant No.2020YFA0608802)。
文摘El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate.
基金Supported by Cultivate Project for the National Natural Science Foundation of China,No.gyfynsfc[2020]-27and National Natural Science Foundation of China,No.81960328.
文摘BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese population.AIM To quantify the natural tumor growth pattern of HCC in regional China.METHODS A retrospective analysis was performed on patients from a single institution in Southwest China who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer therapy.Tumor growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced radiologists.Simple univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical factors.RESULTS This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 months.CONCLUSION The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of China.Given the observed heterogeneity in HCC growth,further investigation is warranted.
基金supported by a grant from the Ministry of Science and Higher Education of Russia, Agreement No. 075-152020-806 (Contract No. 13.1902.21.0014)。
文摘It is known that injection of carbon dioxide into the petroleum reservoir(CO_(2) flooding) is one of the effective methods for enhanced oil recovery. CO_(2) flooding may be complicated by formation of CO_(2) hydrate plugs. It makes topical investigation of CO_(2) hydrate formation in the system gaseous CO_(2)-oil-water. In this work, the growth rates of carbon dioxide hydrate films at the water-oil as well as the water-gas interface are studied in the pressure range of 2.30-3.04 MPa and at temperatures between -5.4 and 5.0℃. It is found that the growth rate for the water-oil interface is 3.5 times lower than that for the water-gas interface with carbon dioxide. It is hypothesised that the observed decrease in the growth rate is related to the mechanical resistance of the oil components adsorbed on the interface to the growth of the hydrate film. The growth rate of the film has been shown to depend on the experimental procedure,most likely due to the different initial concentrations of carbon dioxide in the aqueous solutions.
文摘Inventory data were available from 96 plots of even-aged,monoculture,tall-open forests of Eucalyptus pilularis Smith,aged 2-63 years,growing in sub-tropical regions along the east coast of Australia.A model was developed relating the maximum possible stem basal area growth rate of individual trees to their stem basal area.For any tree size,this maximum increased as site productivity increased.However,the size at which this maximum occurred decreased as productivity increased.Much research has shown that,at any stand age,trees of a particular stem basal area are taller on more productive sites than on less productive ones.Taller trees incur greater respiratory costs to ensure maintenance of the photo synthetic capacity of their canopies;this reduces their growth rates.It was concluded that trees with larger basal areas will have the maximum possible growth rate on a less productive site,whilst trees with smaller basal areas will have the maximum possible on a more productive site.The model developed may constitute the first stage of a complete individual tree growth model system to predict wood yields from these forests.
基金supported by the 2023 scientific promotion program funded by Jeju National University.
文摘Objective:To evaluate the effects of an aqueous extract of Protaetia brevitarsis(AEPB)on the growth of zebrafish and preosteoblast MC3T3-E1 cells.Methods:The effects of AEPB on the linear growth and the expression of growth-related genes in zebrafish and MC3T3-E1 cells were assessed using various molecular techniques.Furthermore,the involvement of the mammalian target of rapamycin(mTOR)pathway in AEPB-induced growth was investigated by employing the mTOR inhibitor rapamycin.Results:AEPB administration led to a significant and dose-dependent increase in zebrafish larvae growth over time.Additionally,AEPB treatment upregulated the expression of growth hormone-1(GH-1),insulin-like growth factor-1(IGF-1),growth hormone receptor-1(GHR-1),and cholecystokinin-a(CCKA)in zebrafish.Similarly,AEPB stimulated the expression and release of IGF-1 and accelerated mTOR expression in MC3T3-E1 cells.In addition,rapamycin hindered AEPB-induced linear growth in zebrafish larvae and suppressed the expression of growth-promoting genes by inhibiting mTOR activation.Conclusions:AEPB shows growth-promoting effects by upregulating growth-related genes and activating the mTOR signaling pathway.Further investigations are warranted to elucidate its mechanisms of action and explore its potential application in the development of growth-enhancing supplements for various purposes.
文摘Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth.
基金国家自然科学基金,Special Foundation of National Excellent Ph.D.Thesis,Outstanding Young Teachers of Ministry of Education of China
文摘Experimental study is performed on the probabilistic models for the long fatigue crack growth rates (da/dN) of LZ50 axle steel. An equation for crack growth rate was derived to consider the trend of stress intensity factor range going down to the threshold and the average stress effect. The probabilistic models were presented on the equation. They consist of the probabilistic da/dN-△K relations, the confidence-based da/dN-△K relations, and the probabilistic- and confidence-based da/dN-△K relations. Efforts were made respectively to characterize the effects of probabilistic assessments due to the scattering regularity of test data, the number of sampling, and both of them. These relations can provide wide selections for practice. Analysis on the test data of LZ50 steel indicates that the present models are available and feasible.
基金financially supported by the National Natural Science Foundation of China(No.51274154)the National High-Tech Research and Development Program of China(No.2012AA03A504)+1 种基金the State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel Group)the Key Project of Hubei Education Committee,China(No.20121101)
文摘The growth rates of bainite plates in an Fe-C-Mn-Si superbainitie steel were investigated by in situ observation. The lengthening rates of ferrite bainite during both cooling and isothermal holding processes were observed and the growth rates of bainite plates nucleating at grain boundaries, within grains and on preformed bainite were measured. It is indicated that the lengthening rates of bainite plates during the cooling and isothermal processes were different, and that the growth rates of bainite plates nucleating at different types of sites also demon- strated diversity. The bainite plates initiating at [vain boundaries during cooling grew the fastest, while the plates nucleating on preformed bainite did the slowest. However, the growth rate of the bainite plates nucleating at grain boundaries during isothermal transformation de- creased the most, whereas the bainite plates initiating within grains grew the fastest. In addition, the growth rate of ferrite bainite in the study supported the diffusion transformation mechanism of bainite from the viewooint of ~rowth rate.
基金National Natural Science Foundation of China(grant numbers 31870427&31730014)by Jiangxi Province 2019 Graduate Innovation Fund Project(grant number YC2019-b061)。
文摘Tree competitiveness generally depends on trait plasticity in response to environmental change.The effects of nitrogen(N)and phosphorus(P)on leaf trait variability by species is poorly understood,especially in China’s subtropical forests.This study examined the seedling leaf traits and net primary productivity of all trees>5 cm DBH of two dominant species,Schima superba and Castanopsis carlesii,in an evergreen broadleaved forest fertilized with nitrogen(+N),phosphorus(+P),and nitrogen plus phosphorus(N+P).The effect of N on seedling leaf traits was stronger than P,while fertilization in general was species dependent.Leaf mass per unit area decreased with N for S.superba seedlings but not for C.carlesii.Leaf N,P,and N/P ratios changed with N addition for both species.All four N fractions of carboxylation,bioenergetics,cell wall,and other N metabolites in C.carlesii leaves responded significantly to fertilization,while only the cell wall in S.superb a leaves responded.Other leaf functional traits,including light-saturated photosynthetic rates,water,N,and P use efficiencies,chlorophyll and non structural carbohydrate contents increased with N addition in S.superb a and by P addition in C.carlesii.Canopy closure at the stand-level increased due to N.Litter biomass and relative growth rate of S.superb a was not affected by any treatments,while both for C.carlesii significantly decreased with N+P addition.Collectively,nutrient limitation may vary at a small scale among species in a subtropical forest based on their responses of seedling traits and net primary productivity to fertilization.Seedling traits are not correlated with the net primary productivity of larger trees except for N fractions,because low light conditions induced by fertilization reduces the proportion of N allocated to photosynthesis in seedlings.In addition,acclimation differences of tree species may increase the uncertainty of community succession.
基金the supports from the Research Foundation for Visiting Scholars of Key Laboratory of Solid Mechanics and FML of Education Ministry,P R Chinathe supports from Japan Society for Promotion of Science
文摘Three types of fatigue tests for an annealed carbon steel containing carbon of 0.42%were carried out on smooth specimens and specimens with a small blind hole in order to investigate the fatigue crack growth law.A simple predicting method for crack growth rates has been proposed involving strengthσband the relation between cyclic stress and strain.The validity of proposed method has been confirmed by experiments on several carbon steels with different loadings.
基金supported by the Government of Malaysia under the 10th and 11th Malaysia Plan.
文摘Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.
基金Supported by Sichuan Provincial Science and Technology Program(Grant No.2022YFH0075)Opening Project of State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure(Grant No.HJGZ2021113)Independent Research Project of State Key Laboratory of Traction Power(Grant No.2022TPL_T03).
文摘Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are difficult to apply in engineering practice.Symbolic regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for datasets.In this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate model.Three terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate models.Based on the FCG rate test data from other literature,the SR model was constructed using Al-7055-T7511.It was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear regression.Compared with the three semi-empirical FCG rate models,the SR model yielded higher prediction accuracy.This result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.
基金Project supported by the National Natural Science Foundation of China(Nos.11672351 and11332007)the National Key R&D Plan(No.2016YFA0401200)the FengLei Youth Innovation Fund of China Aerodynamics Research and Development Center(No.KT-FLJJ-201803)
文摘The elementary task is to calculate the growth rates of disturbances when the e;method in transition prediction is performed. However, there is no unified knowledge to determine the growth rates of disturbances in three-dimensional(3 D) flows. In this paper, we study the relation among the wave parameters of the disturbance in boundary layers in which the imaginary parts of wave parameters are far smaller than the real parts.The generalized growth rate(GGR) in the direction of group velocity is introduced, and the conservation relation of GGR is strictly deduced in theory. This conservation relation manifests that the GGR only depends on the real parts of wave parameters instead of the imaginary parts. Numerical validations for GGR conservation are also provided in the cases of first/second modes and crossflow modes. The application of GGR to the eN method in 3 D flows is discussed, and the puzzle of determining growth rates in 3 D flows is clarified. A convenient method is also proposed to calculate growth rates of disturbances in 3 D flows. Good agreement between this convenient method and existing methods is found except the condition that the angle between the group velocity direction and the x-direction is close to 90?which can be easily avoided in practical application.
文摘Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and duration of their formation are sparse, mainly due to the difficulties extracting datable minerals suited to traditional radiometric dating methods. Hollandite, cryptomelane, coronadite, todorokite, and manjiroite are common manganese oxide minerals in supergene environments. These minerals host potassium of variable amounts from 0.1 wt% to 5.0 wt% in their structural sites. This geochemical property provides possibility to date supergene manganese ores by using K-Ar and 40Ar/ 39Ar methods. In this study, we perform 40Ar/ 39Ar dating on a 7.1-cm-thick botryoidal manganese nodule from an ancient weathering profile at Mount Tabor, central Queensland, Australia. Laser microprobe incremental analyses of distinct growth bands, from the inner core through the intermediate bands to the outermost crusts of the nodule, have yielded high quality 40Ar/ 39Ar ages at 27.3 Ma, 20.9 Ma, 19.2 Ma, and 16.1 Ma, respectively. The age results permit preliminary estimates on the average growth rates of the nodule varying from 4.7×10 -3 mm/ka to 7.6×10 -3 mm/ka to 9.0×10 -3 mm/ka, from the core to the rim. Results of this study are of significance in our understanding of the mode, mechanism, process, and climatic conditions in the formation of supergene manganese ore deposits.
基金supported by the Ministry of Science and Technology of China (Grant No. 2017YFC1501403)the National Natural Science Foundation of China (Grant No. 41575143)+2 种基金the China “1000 Plan” Young Scholar Programthe State Key Laboratory of Earth Surface Processes and Resource Ecology,and the Fundamental Research Funds for the Central Universitiessupported by the Ministry of Science and Technology of China
文摘Growth of fine aerosol particles is investigated during the Aerosol-CCN-Cloud Closure Experiment campaign in June 2013 at an urban site near Beijing. Analyses show a high frequency (- 50%) of fine aerosol particle growth events, and show that the growth rates range from 2.1 to 6.5 nm h-1 with a mean value of - 5.1 nm h-1. A review of previous studies indicates that at least four mechanisms can affect the growth of fine aerosol particles: vapor condensation, intramodal coagulation, extramodal coagulation, and multi-phase chemical reaction. At the initial stage of fine aerosol particle growth, condensational growth usually plays a major role and coagulation efficiency generally increases with particle sizes. An overview of previous studies shows higher growth rates over megacity, urban and boreal forest regions than over rural and oceanic regions. This is most likely due to the higher condensational vapor, which can cause strong condensational growth of fine aerosol particles. Associated with these multiple factors of influence, there are large uncertainties for the aerosol particle growth rates, even at the same location.
基金The Zhejiang Provincial Natural Science Foundation of China under contract No.Y5080149 the National Natural Scientifie Foundation of China under contract No.40406028
文摘Partial sequence of Skeletonema costatum proliferating cell nuclear antigen (PCNA) gene was obtained by reverse transcriptase PCR(RT-PCR) and 3' rapid amplification of cDNA ends (3'-RACE) techniques. Based on the obtained PCNA and cytochrome b gene( Cyt b gene) sequences, a real-time fluorescent quantitative PCR (FQ-PCR) method was developed to detect the expression S. costatum PCNA gene, and this method was applied to study the relationship between the growth rate of S. costatum and the average expression amount of PCNA gene in a single cell. The expression amount of PCNA gene had large variation in cells collected at different culture phases, and the trend was well consistent with the growth rate, which suggested that the expression amount of PCNA gene correlated well with the cell division, and the PCNA could be a promising indicator for the S. costatum cell proliferation. Furthermore, using the PCNA gene as the objective gene and the Cyt b gene as the house-keeping gene, a new method for estimating the in situ growth rate of S. costatum was established by analysis of the relative expression quantity (REQ) of the PCNA gene.
文摘The Monte- Carlo method is used to simulate the surface fatigue crack growth rate for offshore structural steel E36-Z35, and to determine the distributions and relevance of the parameters in the Paris equation. By this method, the time and cost of fatigue crack propagation testing can be reduced. The application of the method is demonstrated by use of four sets of fatigue crack propagation data for offshore structural steel E36-Z35. A comparison of the test data with the theoretical prediction for surface crack growth rate shows the application of the simulation method to the fatigue crack propagation tests is successful.
基金Supported by the National Key Research and Development Program of China(Nos.2017YFC1404403,2016YFC1401602)the National Natural Science Foundation of China(No.41806018)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050502)。
文摘Identifying the main factors on spatial diff erences in net growth rate of Yesso scallop(Patinopecten yessoensis)in culture system is the key to eff ective aquaculture management and development.Coupling a 3D ecosystem model(ROMS-CoSiNE)with a dynamic energy budget model for scallops,a Yesso scallop culture ecosystem(YeSCE)model was established with which scallop growth was simulated with real seeding density and juvenile size from local aquaculture experiments from December 1,2012 to November 30,2013.Results show that the YeSCE model has reasonably simulated the environmental variation and scallop net growth rate in the Changhai sea area.The growth of scallops was slow in winter and midsummer and was limited mainly by temperature.Food availability was a key factor that contributed to the fast growth of the scallops during spring to early summer and in autumn.Generally,the scallops cultured in the north part of the Changhai sea area grew faster than those in the south;and the net growth rate for scallops cultured near the island was signifi cantly higher compare to the others,which is probably correlated to the spatial distribution of food availability.Based on the correlation analysis,the spatial diff erences of the net growth rate were largely aff ected by the length of the match timing of temperatures and food availability.The results of this study provide a scientifi c support for optimizing bottom culture planning and adjusting bottom culture methods.
基金The National Natural Science Foundation of China under contract No.91428203the Guangxi Scientific Projects under contract Nos AD17129063 and AA17204074the Bagui Fellowship from Guangxi of China
文摘The 4.2 ka event that occurred during the period from 4 500–3 900 a BP was characterized by cold and dry climates and resulted in the collapse of civilizations around the world. The cause of this climatic event, however, has been under debate. We collected four corals(Porites lutea) from Yongxing Island, Xisha Islands, South China Sea, dated them with the U-series method, and measured the annual coral growth rates using X-ray technology. The dating results showed that the coral growth ages were from 4 500–3 900 a BP, which coincide well with the period of the4.2 ka event. We then reconstructed annual sea surface temperature anomaly(SSTA) variations based on the coral growth rates. The growth rate-based SSTA results showed that the interdecadal SSTA from 4 500–3 900 a BP was lower than that during modern times(1961–2008 AD). A spectral analysis showed that the SSTA variations from4 500–3 900 a BP were under the influence of El Nino-Southern Oscillation(ENSO) activities. From 4 500–4 100 a BP, the climate exhibited La Nina-like conditions with weak ENSO intensity and relatively stable and lower SSTA amplitudes. From 4 100–3 900 a BP, the climate underwent a complicated period of ENSO variability and showed alternating El Nino-or La Nina-like conditions at interdecadal time scales and large SSTA amplitudes. We speculate that during the early and middle stages of the 4.2 ka event, the cold climate caused by weak ENSO activities largely weakened social productivity. Then, during the end stages of the 4.2 ka event, the repeated fluctuations in the ENSO intensity caused frequent extreme weather events, resulting in the collapse of civilizations worldwide. Thus, the new evidence obtained from our coral records suggests that the 4.2 ka event as well as the related collapse of civilizations were very likely driven by ENSO variability.
基金the National Natural Science Foundation of China(Grant Nos.62074077,61921005,61974062,and 61974065)the Fundamental Research Funds for the Central Universities,China(Grant No.14380166)+3 种基金Key R&D Program of Jiangsu Province,China(Grant No.BE2020004-3)the National Key R&D Program of China(Grant No.2017YFB0404101)Nature Science Foundation of Jiangsu Province,China(Grant No.BE2015111)Collaborative Innovation Center of Solid State Lighting and Energysaving Electronics.
文摘A systematic investigation on PA-MBE grown GaN with low growth rates(less than 0.2μm/h)has been conducted in a wide growth temperature range,in order to guide future growth of sophisticated fine structures for quantum device applications.Similar to usual growths with higher growth rates,three growth regions have been revealed,namely,Ga droplets,slightly Ga-rich and N-rich 3D growth regions.The slightly Ga-rich region is preferred,in which GaN epilayers demonstrate optimal crystalline quality,which has been demonstrated by streaky RHEED patterns,atomic smooth surface morphology,and very low defect related yellow and blue luminescence bands.The growth temperature is a critical parameter to obtain high quality materials and the optimal growth temperature window(~700-760℃)has been identified.The growth rate shows a strong dependence on growth temperatures in the optimal temperature window,and attention must be paid when growing fine structures at a low growth rate.Mg and Si doped GaN were also studied,and both p-and n-type materials were obtained.