期刊文献+
共找到465,148篇文章
< 1 2 250 >
每页显示 20 50 100
Seasonal Variation of the Sea Surface Temperature Growth Rate of ENSO
1
作者 Xinyi XING Xianghui FANG +1 位作者 Da PANG Chaopeng JI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第3期465-477,共13页
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
关键词 SST growth rate intertropical convergence zone zonal advective feedback mixed layer depth ENSO seasonal variation
下载PDF
Genetic and Agronomic Parameter Estimates of Growth, Yield and Related Traits of Maize (Zea mays L.) under Different Rates of Nitrogen Fertilization
2
作者 Prince Emmanuel Norman Lansana Kamara +6 位作者 Aloysius Beah Kelvin Sahr Gborie Francess Sia Saquee Sheku Alfred Kanu Fayia Augustine Kassoh Yvonne Sylvia Gloria Ethel Norman Abdul Salaam Kargbo 《American Journal of Plant Sciences》 CAS 2024年第4期274-291,共18页
This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in... This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize. 展开更多
关键词 Nitrogen rates Genetic and Agronomic Estimates Introduced Genotypes Grain Yield Zea mays
下载PDF
TBAB hydrate formation and growth in a microdevice under static and dynamic conditions
3
作者 Xingxun Li Ming Liu +3 位作者 Qingping Li Weixin Pang Guangjin Chen Changyu Sun 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1396-1404,共9页
The natural gas hydrate has become one of the most promising future green energy sources on the earth.The natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydra... The natural gas hydrate has become one of the most promising future green energy sources on the earth.The natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydrate formation and growth processes in the porous medium is of significance for the exploitation of natural gas hydrate. The micro-packed bed device is one of the efficient microfluidic devices in the engineering field, but it has been rarely used for the hydrate-based research. In this study, a transparent micro-packed bed device filled with glass beads was developed to mimic the porous condition of sediments, and used to in-situ visualize the hydrate formation and growth habits in the pore spaces under both static and dynamic conditions. For the static experiment, two types of hydrate growth patterns in porous medium were observed and identified in the micro-packed bed device, which were the graincoating growth and pore-filling growth. For the dynamic condition, the hydrate formation, growth,distribution habits and hydrate blockage phenomena in the pore spaces were in-situ visually captured.The impacts of flowrate and subcooling on the pressure variation of the micro-packed bed and the duration of the hydrate growth under dynamic flow condition in pores were in-situ monitored and analyzed. The higher flowrate could result in the faster hydrate growth and more severe blockage in pores, but the effect of subcooling condition might be less significant at the high flowrate. 展开更多
关键词 Hydrate formation Hydrate growth MICRODEVICE In-situ measurement
下载PDF
Controllable step-flow growth of GaN on patterned freestanding substrate
4
作者 Peng Wu Jianping Liu +7 位作者 Lei Hu Xiaoyu Ren Aiqin Tian Wei Zhou Fan Zhang Xuan Li Masao Ikeda Hui Yang 《Journal of Semiconductors》 EI CAS CSCD 2024年第2期46-50,共5页
A new kind of step-flow growth mode is proposed,which adopts sidewall as step source on patterned GaN substrate.The terrace width of steps originated from the sidewall was found to change with the growth temperature a... A new kind of step-flow growth mode is proposed,which adopts sidewall as step source on patterned GaN substrate.The terrace width of steps originated from the sidewall was found to change with the growth temperature and ammonia flux.The growth mechanism is explained and simulated based on step motion model.This work helps better understand the behaviors of step advancement and puts forward a method of precisely modulating atomic steps. 展开更多
关键词 step-flow growth GAN terrace width step motion
下载PDF
Control of GaN inverted pyramids growth on c-plane patterned sapphire substrates
5
作者 Luming Yu Xun Wang +8 位作者 Zhibiao Hao Yi Luo Changzheng Sun Bing Xiong Yanjun Han Jian Wang Hongtao Li Lin Gan Lai Wang 《Journal of Semiconductors》 EI CAS CSCD 2024年第6期92-96,共5页
Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane... Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane patterned sapphire substrates(PSS)by metal organic vapor phase epitaxy(MOVPE).The influences of growth conditions on the surface morphol-ogy are experimentally studied and explained by Wulff constructions.The competition of growth rate among{0001},{1011},and{1122}facets results in the various surface morphologies of GaN.A higher growth temperature of 985 ℃ and a lowerⅤ/Ⅲratio of 25 can expand the area of{}facets in GaN inverted pyramids.On the other hand,GaN inverted pyramids with almost pure{}facets are obtained by using a lower growth temperature of 930℃,a higherⅤ/Ⅲratio of 100,and PSS with pattern arrangement perpendicular to the substrate primary flat. 展开更多
关键词 inverted pyramids GAN MOVPE crystal growth competition model
下载PDF
Effects of site productivity on individual tree maximum basal area growth rates of Eucalyptus pilularis in subtropical Australia
6
作者 P.W.West 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1659-1668,共10页
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
关键词 growth model Individual tree Maximum growth rate Eucalyptus pilularis Physiological eff ects
下载PDF
Growth rate of CO_(2) hydrate film on water-oil and water-gaseous CO_(2) interface
7
作者 Tatyana P.Adamova Sergey S.Skiba +1 位作者 Andrey Yu.Manakov Sergey Y.Misyura 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第4期266-272,共7页
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
关键词 Gas hydrate OIL Carbon dioxide growth rate Hydrate film
下载PDF
Crack Growth Rate Model Derived from Domain Knowledge-Guided Symbolic Regression
8
作者 Shuwei Zhou Bing Yang +2 位作者 Shoune Xiao Guangwu Yang Tao Zhu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期286-301,共16页
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
关键词 Fatigue crack growth rate Stress intensity factor range Threshold stress intensity factor range R-RATIO Symbolic regression Machine learning
下载PDF
Aqueous extract of Protaetia brevitarsis larvae increases mTOR-mediated growth rate in zebrafish larvae
9
作者 Jayasingha Arachchige Chathuranga Chanaka Jayasingha Kyoung Tae Lee +1 位作者 Yung Hyun Choi Gi-Young Kim 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2023年第8期339-347,共9页
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
关键词 Protaetia brevitarsis growth rate growth hormone Insulin-like growth factor MTOR MC3T3-E1
下载PDF
Relationship of Trace Elements Concentration and Growth Rate in Alsidium triquetrum (Rhodophyta)
10
作者 Arsenio J. Areces Ruben Cabrera +1 位作者 Jhoana Díaz-Larrea Ligia Collado-Vides 《American Journal of Plant Sciences》 CAS 2023年第3期323-338,共16页
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
关键词 Alsidium growth rate MANGANESE Trace Elements
下载PDF
Phytochemical Contents and Antioxidant Properties of Ganoderma lucidum Polysaccharides in Relation to Growth Stage and Culture Substrate 被引量:1
11
作者 Guoying LU Aizhen HE +4 位作者 Jinrong CHEN Zhouwei XU Chaolian HE Jianfei CHEN Zuofa ZHANG 《Medicinal Plant》 CAS 2023年第3期5-8,14,共5页
[Objectives]To determine physicochemical characteristics and antioxidant activity of Ganoderma lucidum polysaccharides(GLP)in different growth stages and culture media.[Methods]Five polysaccharides(GLP1,GLP2,GLP3,GLPW... [Objectives]To determine physicochemical characteristics and antioxidant activity of Ganoderma lucidum polysaccharides(GLP)in different growth stages and culture media.[Methods]Five polysaccharides(GLP1,GLP2,GLP3,GLPW and GLPB)were extracted and purified from the fruiting body of G.lucidum at three growth stages and culture substrates(wood culture and bag culture).The chemical components and antioxidant activity of the five polysaccharides were determined.[Results]GLP1 contained the highest content of neutral sugar(87.65%)and GLP3 had the highest uronic acid content.All the samples mainly comprised glucose,galactose,mannose,xylose and arabose with different ratios.Moreover,their antioxidant activities were investigated on the basis of DPPH radical,ABTS radical,SOD-like activity,and antihaemolytic activity.Results indicated in all three growth stages GLP2 had the greatest antioxidant properties.In addition,the antioxidant activity of GLPW was significantly higher than that of GLPB.[Conclusions]Overall,by comparison,G.lucidum in growth stage two may have potential health benefits,and wood culture may be a superior choice of artificial cultivation due to their abundance of active polysaccharides. 展开更多
关键词 Ganoderma lucidum POLYSACCHARIDES Antioxidant activity growth stage Culture substrate
下载PDF
Probability estimation method for fatigue crack growth rate based on a∼t data from service
12
作者 Niansheng Xi Hongmin Xu 《Railway Sciences》 2023年第3期347-357,共11页
Purpose–The study aims to provide a basis for the effective use of safety-related information data and a quantitative assessment way for the occurrence probability of the safety risk such as the fatigue fracture of t... Purpose–The study aims to provide a basis for the effective use of safety-related information data and a quantitative assessment way for the occurrence probability of the safety risk such as the fatigue fracture of the key components.Design/methodology/approach–The fatigue crack growth rate is of dispersion,which is often used to accurately describe with probability density.In view of the external dispersion caused by the load,a simple and applicable probability expression of fatigue crack growth rate is adopted based on the fatigue growth theory.Considering the isolation among the pairs of crack length a and crack formation time t(a∼t data)obtained from same kind of structural parts,a statistical analysis approach of t distribution is proposed,which divides the crack length in several segments.Furthermore,according to the compatibility criterion of crack growth,that is,there is statistical development correspondence among a∼t data,the probability model of crack growth rate is established.Findings–The results show that the crack growth rate in the stable growth stage can be approximately expressed by the crack growth control curve da/dt=5 Q•a,and the probability density of the crack growth parameter Q represents the external dispersion;t follows two-parameter Weibull distribution in certain a values.Originality/value–The probability density f(Q)can be estimated by using the probability model of crack growth rate,and a calculation example shows that the estimation method is effective and practical. 展开更多
关键词 Crack growth a∼t data growth rate Probability estimation
下载PDF
基于FP-growth的老年行人交通事故损伤致因研究
13
作者 刘永涛 张慧臣 +3 位作者 袁诗泉 高隆鑫 王鹏 赵晨 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第6期176-182,共7页
为研究老年行人交通事故相关因素及其对损伤程度的影响,以中国交通事故深度调查数据库中2013—2023年710起机动车-老年行人事故为分析对象,利用FP-growth算法挖掘出4类影响因素28个类型变量共5594项关联规则。研究结果表明:行人年龄、... 为研究老年行人交通事故相关因素及其对损伤程度的影响,以中国交通事故深度调查数据库中2013—2023年710起机动车-老年行人事故为分析对象,利用FP-growth算法挖掘出4类影响因素28个类型变量共5594项关联规则。研究结果表明:行人年龄、碰撞速度、事故时间段及事故地点是影响老年行人事故死亡率的显著因素。特别是,行人年龄和碰撞速度对死亡率有显著影响,随着碰撞速度的增加,死亡率显著上升;60岁及以上老年行人年龄每增加1岁,其死亡率提升0.037倍。此外,事故发生在夜间、郊区或村庄的死亡率更高。研究结果可为提高老年行人交通安全,制定相关安全措施提供一定参考。 展开更多
关键词 FP-growth算法 逻辑回归模型 老年行人安全 交通事故数据分析
下载PDF
Dynamic changes of rumen microbiota and serum metabolome revealed increases in meat quality and growth performances of sheep fed bio‑fermented rice straw
14
作者 Yin Yin Kyawt Min Aung +6 位作者 Yao Xu Zhanying Sun Yaqi Zhou Weiyun Zhu Varijakshapanicker Padmakumar Zhankun Tan Yanfen Cheng 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第3期1207-1226,共20页
Background Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed.Our previous study showed that feeding bio-fermented rice straw(BF)improv... Background Providing high-quality roughage is crucial for improvement of ruminant production because it is an essential component of their feed.Our previous study showed that feeding bio-fermented rice straw(BF)improved the feed intake and weight gain of sheep.However,it remains unclear why feeding BF to sheep increased their feed intake and weight gain.Therefore,the purposes of this research were to investigate how the rumen micro-biota and serum metabolome are dynamically changing after feeding BF,as well as how their changes influence the feed intake,digestibility,nutrient transport,meat quality and growth performances of sheep.Twelve growing Hu sheep were allocated into 3 groups:alfalfa hay fed group(AH:positive control),rice straw fed group(RS:negative control)and BF fed group(BF:treatment).Samples of rumen content,blood,rumen epithelium,muscle,feed offered and refusals were collected for the subsequent analysis.Results Feeding BF changed the microbial community and rumen fermentation,particularly increasing(P<0.05)relative abundance of Prevotella and propionate production,and decreasing(P<0.05)enteric methane yield.The histomorphology(height,width,area and thickness)of rumen papillae and gene expression for carbohydrate trans-port(MCT1),tight junction(claudin-1,claudin-4),and cell proliferation(CDK4,Cyclin A2,Cyclin E1)were improved(P<0.05)in sheep fed BF.Additionally,serum metabolome was also dynamically changed,which led to up-regulating(P<0.05)the primary bile acid biosynthesis and biosynthesis of unsaturated fatty acid in sheep fed BF.As a result,the higher(P<0.05)feed intake,digestibility,growth rate,feed efficiency,meat quality and mono-unsaturated fatty acid concentration in muscle,and the lower(P<0.05)feed cost per kg of live weight were achieved by feeding BF.Conclusions Feeding BF improved the growth performances and meat quality of sheep and reduced their feed cost.Therefore,bio-fermentation of rice straw could be an innovative way for improving ruminant production with mini-mizing production costs. 展开更多
关键词 Bio-fermentation growth rate Meat quality METABOLOME MICROBIOTA Rice straw
下载PDF
RMB Exchange Rate,Overseas Education,and High-Quality Economic Growth
15
作者 Sun Yuchen Sun Xianchao 《Contemporary Social Sciences》 2023年第6期97-118,共22页
China is transitioning its industrial structure from labor-and resource-intensive industries that previously contributed significantly to the country’s GDP growth to technology-intensive industries emphasizing a high... China is transitioning its industrial structure from labor-and resource-intensive industries that previously contributed significantly to the country’s GDP growth to technology-intensive industries emphasizing a highly-skilled workforce and sustainability to achieve high-quality economic growth.This paper examines the impact of the RMB exchange rate on high-quality economic growth through theoretical modeling and empirical analysis and discusses the variable of overseas education to explore the mechanism of how the RMB exchange rate and overseas education jointly impact high-quality economic growth.The research sample includes the National Bureau of Statistics data on education from 1995 to 2015,the Bank for International Settlements(BIS)data on the RMB exchange rate,and the added value of China’s high-quality economic growth estimated based on the national economy data.An empirical analysis of theoretical expectations was conducted,finding that RMB appreciation could make a positive contribution to China’s high-quality economic growth;RMB exchange rate fluctuations would impact the relative cost of overseas education and overseas returnees could have a positive impact on domestic resource utilization efficiency and domestic capacity to make sci-tech innovations,thereby injecting vitality to high-quality economic growth.This study focuses on both the RMB exchange rate and the population studying abroad,providing additional observation dimensions to existing research. 展开更多
关键词 RMB exchange rate overseas education high-quality economic growth
下载PDF
The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation 被引量:2
16
作者 Lei ZHU Chunsong LU +5 位作者 Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期173-187,共15页
The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameteri... The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization. 展开更多
关键词 large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution
下载PDF
Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei 被引量:1
17
作者 Shicheng Su Nianqing Jin Xiaoli Wei 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期12-28,共17页
Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in... Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted. 展开更多
关键词 THINNING Understory light environment Phoebe bournei Photosynthetic performance growth performance
下载PDF
Chicken chromatin accessibility atlas accelerates epigenetic annotation of birds and gene fine-mapping associated with growth traits
18
作者 Xiao-Ning Zhu Yu-Zhe Wang +3 位作者 Chong Li Han-Yu Wu Ran Zhang Xiao-Xiang Hu 《Zoological Research》 SCIE CAS CSCD 2023年第1期53-62,共10页
The development of epigenetic maps, such as the ENCODE project in humans, provides resources for gene regulation studies and a reference for research of disease-related regulatory elements. However,epigenetic informat... The development of epigenetic maps, such as the ENCODE project in humans, provides resources for gene regulation studies and a reference for research of disease-related regulatory elements. However,epigenetic information, such as a bird-specific chromatin accessibility atlas, is currently lacking for the thousands of bird species currently described.The major genomic difference between birds and mammals is their shorter introns and intergenic distances, which seriously hinders the use of humans and mice as a reference for studying the function of important regulatory regions in birds. In this study, using chicken as a model bird species, we systematically compiled a chicken chromatin accessibility atlas using 53 Assay of Transposase Accessible Chromatin sequencing(ATAC-seq)samples across 11 tissues. An average of 50 ?796open chromatin regions were identified per sample,cumulatively accounting for 20.36% of the chicken genome. Tissue specificity was largely reflected by differences in intergenic and intronic peaks, with specific functional regulation achieved by two mechanisms: recruitment of several sequence-specific transcription factors and direct regulation of adjacent functional genes. By integrating data from genome-wide association studies, our results suggest that chicken body weight is driven by different regulatory variants active in growth-relevant tissues. We propose CAB39L(active in the duodenum), RCBTB1(muscle and liver), and novel long non-coding RNA ENSGALG00000053256(bone) as candidate genes regulating chicken body weight. Overall, this study demonstrates the value of epigenetic data in fine-mapping functional variants and provides a compendium of resources for further research on the epigenetics and evolution of birds and mammals. 展开更多
关键词 CHICKEN Chromatin accessibility atlas ATAC-seq Tissue-specific OCRs GWAS growth traits
下载PDF
Effects of Different Levels of Garlic Powder Incorporated in the Feed Enriched with Stylosanthes guianensis on Reproduction and Pre-Weaning Growth Performances of Cavies (Cavia porcellus)
19
作者 Martin Vidal Tatang Emile Miégoué +6 位作者 Margaret Mary Momo Chongsi Wouafo David Fokom Nyah Cédric Kwayep Paulette Ntsafack Tobou France-Gina Djoumessi Mathieu Duclos Fogang Fernand Tendonkeng 《Open Journal of Animal Sciences》 2023年第4期574-589,共16页
In order to increase the productivity of the local cavies as a meat animal, a study was carried out between November 2021 and March 2022 at the Research and Experimental Farm, Animal Nutrition and Production Research ... In order to increase the productivity of the local cavies as a meat animal, a study was carried out between November 2021 and March 2022 at the Research and Experimental Farm, Animal Nutrition and Production Research Unit of the Faculty of Agronomy and Agricultural Sciences (FAAS) and the Microbiology and Anti-Microbial Research Unite of the University of Dschang on 72 cavies aged between 4 and 5 months and weighing an average of 450 ± 50 g produced on the farm, including 60 females and 12 males. The females were distributed according to a completely randomized factorial design in twelve (12) rearing boxes numbered G1 to G12, with 15 females per group distributed in 03 boxes and receiving iso-nitrogenated experimental diet (18% protein) R0 enriched with 20% of Stylosanthes guianensis (0% garlic powder), R0.25 (0.25% garlic powder), R0.50 (0.50% garlic powder) and R0.75 (0.75% garlic powder). Females were identified by numbered ear tags and mated with a sex ratio of 5 females for 1 male. Drinking water enriched with vitamin C (01 tablet of 240 mg in 1.5 liters of water) was served ad libitum and renewed daily. The males were removed after 31 days. A form was established to record the weight of each pregnant female, any abortions during gestation, the date of parturition and the date of birth of each newborn, as well as the number of live-born or stillborn pups. After parturition, the weights of female and newborn cavies were recorded weekly until the 3<sup>rd</sup> week. The number of cavies that died before weaning and the number of live weaned cavies were also recorded. Reproductive performance significantly increased (p 0.05) fertility rate and net fertility rate, litter size, birth viability rate, and pre-weaning viability rate with rations containing garlic powder, compared to the control ration, especially with the R0.50 ration. In addition, birth mortality and pre-weaning mortality were significantly lower (p 0.05) with rations containing the additive, compared to those of the control ration (R0). However, the R0.50 ration showed the lowest rates, followed by the R0.25 ration, and finally the R0.75 ration. Weight development of young cavies increased with all rations but was more marked with the R0.50 ration. Only total weight gain (TG) and average daily weight gain (ADG) in the pre-weaning phase were significantly increased (p < 0.05) with rations R0.25 and R0.50. 展开更多
关键词 Cavy Garlic Powder Pre-Weaning growth REPRODUCTION Stylosanthes guianensis
下载PDF
Construction of a Computational Scheme for the Fuzzy HIV/AIDS Epidemic Model with a Nonlinear Saturated Incidence Rate 被引量:1
20
作者 Muhammad Shoaib Arif Kamaleldin Abodayeh Yasir Nawaz 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1405-1425,共21页
This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemi... This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters. 展开更多
关键词 Epidemic model fuzzy rate parameters next generation matrix local stability proposed numerical scheme
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部