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Coupling Effect of Water and Fertilizer on Soybean Yield and Nutrient Absorption 被引量:2
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作者 HAO Li ZU Wei +2 位作者 SUN Cong-shu LEI Shu-xia LIU Li-jun 《Journal of Northeast Agricultural University(English Edition)》 CAS 2003年第2期105-114,共10页
Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertili... Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertilizer application,and vice versa;pods per plant,seeds per pod.and 100-seed weight had positive correlations with soybean yield,but the degrees of correlations of different treatments were various;LAI and dry matter accumulation could be significantly increased when watered and applied fertilizer with different levels,but high fertilizer application treatment didn't obtain the highest yield;watering could increase the absolute absorption amount of N,P,K in seeds,but the accumulation rates were various. 展开更多
关键词 coupling effect water fertilizer soybean yield
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Coupling Effect of Water and Phosphate on Economic Traits of Sugarcane 被引量:3
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作者 陆国盈 蒋明明 +4 位作者 韩世健 裴铁雄 汤雪莲 秦洪波 Guo-ying Ming-ming Shi-jian Tie-xiong Xue-lian Hong-bo 《Agricultural Science & Technology》 CAS 2010年第5期62-65,120,共5页
[Objective] The aim was to study the coupling effect of water and phosphate on economic traits of sugarcane. [Method] Taking sugarcane variety ROC22 as tested material,coupling effects of different levels of water sup... [Objective] The aim was to study the coupling effect of water and phosphate on economic traits of sugarcane. [Method] Taking sugarcane variety ROC22 as tested material,coupling effects of different levels of water supply quantity and different levels of phosphorus fertilizer on the yield and quality of sugarcane were studied. Among them,water supply quantity had 3 levels,that was,the water supply quantity per 10 days from the early tillering stage of sugarcane to the end of elongation was 199.5 m3/hm2 (A1),400.5 m3/hm2 (A2) and 600.0 m3/hm2 (A3),respectively; Phosphorus fertilizer as basic fertilizer had 4 levels:P2O5 0 kg/hm2 (B1),120 kg/hm2 (B2),240 kg/hm2 (B3) and 360 kg/hm2 (B4). [Result] Treatment A3B2 in water-fertilizer coupling was more suitable to improve economic traits of sugarcane. [Conclusion] The research results provide theoretical basis for the efficient utilization of water and phosphorus fertilizer in production of Guangxi sugarcane and the cultivation of high-yield and high-glucose sugarcane. 展开更多
关键词 Sugarcane water Phosphorus fertilizer water-phosphate coupling Economic traits
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Effects of Seeding Rate, Water and Fertilizer Coupling on Grass Yield of Forage Millet ( Setaria itlica) in Hebei
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作者 Zhou Hanzhang Liu Huan +4 位作者 Zhou Xinjian Wei Zhimin Yuan Shuhong Hou Shenglin Xia Xueyan 《Animal Husbandry and Feed Science》 CAS 2016年第5期283-290,314,共9页
The paper was to study the effects of seeding rate, water and fertilizer ( N, P, K) coupling on grass yield of forage millet Jigu No. 18 (Setaria itlica). A quadratic regression otthogonal rotation combination wit... The paper was to study the effects of seeding rate, water and fertilizer ( N, P, K) coupling on grass yield of forage millet Jigu No. 18 (Setaria itlica). A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet (Y) and soil moisture content ( x1 ), N fertilizer (x2 ), P fertilizer (x3 ), K fertilizer (x4) and seeding rate (x5 ) was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 + 1. 052x^x2 + 1. 604xIx3 + 12. 953xt x5 - 0. 173x2x3 + 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% ( 3 288.98 yuan/hm^2 ) compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province. 展开更多
关键词 Forage millet Seeding rate water and fertilizer coupling Hay yield
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Effects of water and fertilizer deficit regulation with drip irrigation at different growth stages on fruit quality improvement of kiwifruit in seasonal arid areas of Southwest China
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作者 ZHA Yu-xuan CHEN Fei +2 位作者 WANG Zhi-hui JIANG Shou-zheng CUI Ning-bo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第10期3042-3058,共17页
For a long time,seasonal drought occurs frequently in Southwest China,and the management of water and fertilizer in kiwifruit orchards has no quantitative standards,which seriously affects the yield and quality of kiw... For a long time,seasonal drought occurs frequently in Southwest China,and the management of water and fertilizer in kiwifruit orchards has no quantitative standards,which seriously affects the yield and quality of kiwifruit.Therefore,the effects of water and fertilizer deficit regulation with drip irrigation(WFDRDI)on the quality of kiwifruit at different growth stages were explored to achieve water and fertilizer saving,and green and efficient production of kiwifruit.We select‘Jin Yan'kiwifruit and set two water deficit levels(W_(D20%)and W_(D40%))and three fertilizer deficit levels(F_(D15%),F_(D30%)and F_(D45%))at bud burst to leafing stage(stageⅠ),flowering to fruit set stage(stageⅡ),fruit expansion stage(stageⅢ)and fruit maturation stage(stageⅣ),respectively,with a full irrigation and fertilization as the control treatment(CK)in 2017and 2018.Results showed that the WFDRDI at stageⅡandⅢhad significant effect on fruit physical quality of kiwifruit,specifically,theⅢ-WD40%F_(D30%)andⅢ-W_(D20%)F_(D45%)treatments significantly increased fruit firmness by 13.62 and 15.59%(P<0.05),respectively;theⅡ-W_(D40%)F_(D15%)andⅢ-W_(D40%)F_(D15%)treatments significantly increased dry matter by 8.19 and 6.47%(P<0.05),respectively;theⅢ-W_(D20%)F_(D15%)treatment significantly increased single fruit weight and fruit volume by 9.33 and 12.65%(P<0.05),respectively;theⅡ-W_(D20%)F_(D15%)treatment significantly increased fruit water content by 1.99%(P<0.05).The WFDRDI had an obvious effect on fruit chemical quality of kiwifruit.TheⅢ-W_(D20%)F_(D45%),Ⅳ-W_(D40%)F_(D15%)andⅣ-W_(D20%)F_(D30%)treatments significantly increased vitamin C(Vc)content by 69.96,36.96 and 34.31%(P<0.05),respectively;theⅢ-W_(D40%)F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments significantly increased total soluble solid(TSS)content by 3.79 and 17.05%(P<0.05),respectively,and significantly increased soluble sugar content by 28.61 and 34.79%(P<0.05),respectively;the contents of fructose,glucose and sucrose also had a significantly increasing trend,which was increased significantly by 5.58–19.63%,40.55–60.36%and 54.03–54.92%in theⅢ-WD40%F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments(P<0.05),respectively;sugar–acid ratio was increased significantly in theⅣ-W_(D40%)F_(D15%)treatment by 64.65%(P<0.05).The degree and duration of water and fertilizer deficit had a comprehensive effect on fruit quality of kiwifruit.The WFDRDI at stageⅡandⅢcontribute to improving fruit physical quality,and the threshold of water and fertilizer deficit were 20 and 15%,respectively;stageⅢandⅣare the critical periods for improving fruit chemical quality by water and fertilizer coupling effect,and the threshold of water and fertilizer deficit were 40 and 15%,respectively.Therefore,aiming at precise water and fertilizer saving,theⅠ-W_(D20%)F_(D30%),Ⅱ-W_(D40%)F_(D15%),Ⅲ-W_(D40%)F_(D15%)andⅣ-W_(D40%)F_(D15%)treatments under WFDRDI during the whole growth period of kiwifruit were the best mode to improve quality and production of kiwifruit. 展开更多
关键词 water deficit fertilizer deficit water and fertilizer coupling fruit physical quality fruit chemical quality
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Spatiotemporal Coupling of Water and Fertilizer for Double-cropping Grape in Guangxi
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作者 Yongxian LIU Yan ZENG +6 位作者 Yanfei HUANG Liumei XIONG Ying ZHANG Muming CAO Yuyi HUANG Guifen CHEN Xianjin BAI 《Asian Agricultural Research》 2016年第4期25-27,31,共4页
This paper summarizes the research progress and major achievements of the coupling effect of water and fertilizer on grape cultivation in China and abroad in recent years,emphatically analyzes the application status a... This paper summarizes the research progress and major achievements of the coupling effect of water and fertilizer on grape cultivation in China and abroad in recent years,emphatically analyzes the application status and some problems of the coupling effect of water and fertilizer on double-cropping grape cultivation mode in Guangxi Zhuang Autonomous Region,discusses the key problems to be further resolved,and finally makes the relevant recommendations. 展开更多
关键词 GRAPE Double CROPPING water and fertilizer coupling Research status
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Study on the Influence of Sowing Rate,Water and Fertilizer Coupling on Water Use Efficiency of Fodder Millet
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作者 Hanzhang ZHOU Huan LIU +4 位作者 Xinjian ZHOU Zhimin WEI Shuhong YUAN Shenglin HOU Xueyan XIA 《Asian Agricultural Research》 2016年第10期77-87,96,共12页
To study the influence of sowing rate,water and fertilizer( N,P and K) coupling on water use efficiency of fodder millet grown in autumn fallow field,taking " Jigu 18" as the tested material,a orthogonal rot... To study the influence of sowing rate,water and fertilizer( N,P and K) coupling on water use efficiency of fodder millet grown in autumn fallow field,taking " Jigu 18" as the tested material,a orthogonal rotation combination with five factors was designed in pot experiment. Results showed that both water and phosphate fertilizer had important impacts on water use efficiency,in which water had the maximum impact,followed by phosphate fertilizer,and nitrogen fertilizer,potassium fertilizer and sowing rate all had no obvious impact. Significant item of sowing rate,water and fertilizer coupling had the below sequence: potassium fertilizer + sowing rate > nitrogen fertilizer + phosphate fertilizer > water + phosphate fertilizer > water + sowing rate > water + potassium fertilizer,and other items had no obvious impact. Mathematical model was established: y = 44. 26- 1. 311x1- 2. 298x2- 3. 682x3- 6. 401x4- 34. 540x5+ 0. 273x1x3+ 0. 118x1x4+ 0. 843x1x5- 1. 948x2x3+ 6. 631x4x5. The optimal scheme taking economic benefit as the examining index was cleared,that is,soil water content maintained 10%,and sowing rate of fodder millet was 15 kg / hm2. By the scheme,water use efficiency was 26. 24 g / kg,and hay yield was13980. 90 kg / hm2,with economic benefit of 13830. 90 yuan/hm2,which was 3063. 73 yuan/hm2 more than the optimized combination with the highest hay yield,with increase magnitude of 22. 15%,and was 6215. 15 yuan / hm2 more than the optimized combination with the highest water use efficiency,with increase magnitude of 44. 94%. The research could provide theoretic basis and technical support for production practice of fodder millet grown in autumn fallow field. 展开更多
关键词 Fodder millet Sowing rate water and fertilizer coupling water use efficiency
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Effect of Fertilizer Diammonium Phosphate on Liver,Kidney and Muscle 5-Nucleotidase Activity of Fresh Water Teleost Fish Clarias batrachus
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作者 T.S.NAQVI M.S.NAQVI R.K.SINGH 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1993年第4期385-388,共4页
The toxic effect of fertilizer Diammonium phosphate resulted in alterations of 5'-Nucleotidase activity of tissues liver, kidney and muscles offish C. batrachus at varying intervals and exposures. Alterations in 5... The toxic effect of fertilizer Diammonium phosphate resulted in alterations of 5'-Nucleotidase activity of tissues liver, kidney and muscles offish C. batrachus at varying intervals and exposures. Alterations in 5'-Nuclcotidase activity of body organs gave an idea of the toxicity caused by the fertilizer. Thus the enzyme 5'-Nucleotidase can be used to monitor the pollution in aquatic ecosystem. 展开更多
关键词 effect of fertilizer Diammonium Phosphate on Liver Kidney and Muscle 5-Nucleotidase Activity of Fresh water Teleost Fish Clarias batrachus
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Combined effects of obstacle and fine water mist on gas explosion characteristics 被引量:5
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作者 Xiaoping Wen Mengming Wang +2 位作者 Fahui Wang Minggao Yu Haoxin Deng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第12期131-140,共10页
Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles... Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles was considered.The results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without obstacles.In the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was significant.The inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles. 展开更多
关键词 Fine water mist Gas explosion suppression OBSTACLE Couple effects
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Coupled hydro-mechanical effect of a fractured rock mass under high water pressure 被引量:2
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作者 Zhongming Jiang Shurong Feng Sheng Fu 《Journal of Rock Mechanics and Geotechnical Engineering》 2012年第1期88-96,共9页
To explore the variation of permeability and deformation behaviors of a fractured rock mass in high water pressure,a high pressure permeability test(HPPT),including measuring sensors of pore water pressure and displ... To explore the variation of permeability and deformation behaviors of a fractured rock mass in high water pressure,a high pressure permeability test(HPPT),including measuring sensors of pore water pressure and displacement of the rock mass,was designed according to the hydrogeological condition of Heimifeng pumped storage power station.With the assumption of radial water flow pattern in the rock mass during the HPPT,a theoretical formula was presented to estimate the coefficient of permeability of the rock mass using water pressures in injection and measuring boreholes.The variation in permeability of the rock mass with the injected water pressure was studied according to the suggested formula.By fitting the relationship between the coefficient of permeability and the injected water pressure,a mathematical expression was obtained and used in the numerical simulations.For a better understanding of the relationship between the pore water pressure and the displacement of the rock mass,a 3D numerical method based on a coupled hydro-mechanical theory was employed to simulate the response of the rock mass during the test.By comparison of the calculated and measured data of pore water pressure and displacement,the deformation behaviors of the rock mass were analyzed.It is shown that the variation of displacement in the fractured rock mass is caused by water flow passing through it under high water pressure,and the rock deformation during the test could be calculated by using the coupled hydro-mechanical model. 展开更多
关键词 fractured rock mass permeability under the condition of high water head hydro-mechanical coupling effect
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Corn Leaf Water Retention as Affected by OrganicFertilizations and Effective Microbes Applications
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作者 XU HUILIAN N. AJIKI +1 位作者 WANG XIAOJU C. SAKAKIBARA and H. UMEMURA (International Nature Farming Research Center, Hata-machi, Nagano 390-14 (Japan)) 《Pedosphere》 SCIE CAS CSCD 1998年第1期1-8,共8页
Effects of organic fertilizers and effective microbes on leaf water retention of sweet corn (Zea mays L. cv.Honey-Bantam) were studied. Sweet corns were grown with organic or chemical fertilizers with or without effec... Effects of organic fertilizers and effective microbes on leaf water retention of sweet corn (Zea mays L. cv.Honey-Bantam) were studied. Sweet corns were grown with organic or chemical fertilizers with or without effective microbes (EM). A water retention curve was obtained by drying the excised leaves under a light of 500 μmol (m2·s)-1. The curve shows two distinct phases. The initial steep slope indicates the water loss speed by stomatal transpiration (Est) and the gentle slope of the second phase indicates water loss speed by cuticular transpiration (Ecu). Both Est and Ecu were lower for leaves of plants grown with organic materials than for those with chemical fertilizers. Addition of EM to both organic and chemical fertilizers decreased Est but showed no effect on Ecu. The water retention ability of the excised leaves was proportional to photosynthetic maintenance ability under soil water deficit conditions as well as the solute concentration in leaves. The results suggested that organic fertilization and EM application increased water stress resistance both under in situ conditions and in excised leaves of sweet corn plants. 展开更多
关键词 cuticular transpiration effective microorganism organic fertilizer water stress Zea mays
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A review of nanocarbons in energy electrocatalysis: Multifunctional substrates and highly active sites 被引量:16
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作者 Cheng Tang Maria-Magdalena Titirici Qiang Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第6期1077-1093,共17页
Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based... Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based electrocatalysts have been revealed to potentially have effective activity and remarkable durability, which is promising to replace precious metals in some important energy technologies,such as fuel cells, metal–air batteries, and water splitting. In this review, rather than overviewing recent progress completely, we aim to give an in-depth digestion of present achievements, focusing on the different roles of nanocarbons and material design principles. The multifunctionalities of nanocarbon substrates(accelerating the electron and mass transport, regulating the incorporation of active components,manipulating electron structures, generating confinement effects, assembly into 3 D free-standing electrodes) and the intrinsic activity of nanocarbon catalysts(multi-heteroatom doping, hierarchical structure,topological defects) are discussed systematically, with perspectives on the further research in this rising research field. This review is inspiring for more insights and methodical research in mechanism understanding, material design, and device optimization, leading to a targeted and high-efficiency development of energy electrocatalysis. 展开更多
关键词 NANOCARBON Energy electrocatalysis Oxygen reduction Oxygen evolution Hydrogen evolution CO_2 reduction Electron structure Strong coupling effect Hierarchical structure DOPING Defect Metal–air battery Fuel cell water splitting
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Amorphous CoOx coupled carbon dots as a spongy porous bifunctional catalyst for efficient photocatalytic water oxidation and CO2 reduction 被引量:4
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作者 Wanjun Sun Xiangyu Meng +5 位作者 Chunjiang Xu Junyi Yang Xiangming Liang Yinjuan Dong Congzhao Dong Yong Ding 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第12期1826-1836,共11页
Cobalt-based oxides,with high abundance,good stability and excellent catalytic performance,are regarded as promising photocatalysts for artificial photosynthetic systems to alleviate foreseeable energy shortages and g... Cobalt-based oxides,with high abundance,good stability and excellent catalytic performance,are regarded as promising photocatalysts for artificial photosynthetic systems to alleviate foreseeable energy shortages and global warming.Herein,for the first time,a series of novel spongy porous CDs@CoOx materials were synthesized to act as an efficient and stable bifunctional photocatalyst for water oxidation and CO2 reduction.Notably,the preparation temperatures visibly influence the morphologies and photocatalytic performances of the CDs@CoOx.Under the optimal conditions,a maximum O2 yield of 40.4% and pretty apparent quantum efficiency(AQE)of 58.6% at 460 nm were obtained over CDs@CoOx-300 for water oxidation.Similarly,the optimized sample CDs@CoOx-300 manifests significant enhancement on the CO2-to-CO conversion with a high selectivity of 89.3% and CO generation rate of 8.1μmol/h,which is superior to most previous cobalt-based catalysts for CO2 reduction.The composite CDs@CoOx-300 not only exposes more active sites but also facilitates electron transport,which results in excellent photocatalytic activity.In addition,the boosted photocatalytic behavior is attributed to the synergistic effect between CoOx and CDs,which was verified by the photocatalytic activity control experiments and electrochemical characterization.The work offers a novel strategy to fabricate a high performance bifunctional photocatalyst for water oxidation and CO2 reduction. 展开更多
关键词 Carbon dots coupled CoOx Bifunctional photocatalyst water oxidation CO2 reduction Synergistic effect
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Optimizing water and nitrogen inputs for winter wheat cropping system on the Loess Plateau,China 被引量:8
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作者 QiuPing FU QuanJiu WANG +1 位作者 XinLei SHEN Jun FAN 《Journal of Arid Land》 SCIE CSCD 2014年第2期230-242,共13页
Optimal use of water and fertilizers can enhance winter wheat yield and increase the efficiencies of water and fertilizer usage in dryland agricultural systems. In order to optimize water and nitrogen (N) management... Optimal use of water and fertilizers can enhance winter wheat yield and increase the efficiencies of water and fertilizer usage in dryland agricultural systems. In order to optimize water and nitrogen (N) management for winter wheat, we conducted field experiments from 2006 to 2008 at the Changwu Agro-ecological Experimental Station of the Chinese Academy of Sciences on the Loess Plateau, China. Regression models of wheat yield and evapotranspiration (ET) were established in this study to evaluate the water and fertilizer coupling effects and to determine the optimal coupling domain. The results showed that there was a positive effect of water and N fertilizer on crop yield, and optimal irrigation and N inputs can significantly increase the yield of winter wheat. In the drought year (2006-2007), the maximum yield (Yma~) of winter wheat was 9.211 t/hm2 for the treatment with 324 mm irriga- tion and 310 kg/hm2 N input, and the highest water use efficiency (WUE) of 16.335 kg/(hm2.mm) was achieved with 198 mm irrigation and 274 kg/hm2 N input. While in the normal year (2007-2008), the maximum winter wheat yield of 10.715 t/hm2 was achieved by applying 318 mm irrigation and 291 kg/hm2 N, and the highest WUE was 18.69 kg/(hm2.mm) with 107 mm irrigation and 256 kg/hm2 N input. Crop yield and ET response to irrigation and N inputs followed a quadratic and a line function, respectively. The optimal coupling domain was determined using the elas- ticity index (El) and its expression in the water-N dimensions, and was represented by an ellipse, such that the global maximum WUE (WUErnax) and Ymax values corresponded to the left and right end points of the long axis, respectively. Considering the aim to get the greatest profit in practice, the optimal coupling domain was represented by the lower half of the ellipse, with the Yma~ and WUE^ax on the two end points of the long axis. Overall, we found that the total amount of irrigation for winter wheat should not exceed 324 ram. In addition, our optimal coupling domain visually reflects the optimal range of water and N inputs for the maximum winter wheat yield on the Loess Plateau, and it may also provide a useful reference for identifying appropriate water and N inputs in agricultural applications. 展开更多
关键词 water-fertilizer coupling water use efficiency optimal coupling domain yield winter wheat
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Experimental Investigation on Vortex-Induced Vibration of Deep-Sea Risers of Different Excitation Water Depths
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作者 LI Peng DONG Zheng-kai +4 位作者 LIU Yu WANG Yu CONG Ai-jun GUO Haiyan FU Qiang 《China Ocean Engineering》 SCIE EI CSCD 2021年第2期215-227,共13页
The vortex-induced vibration test of the deep-sea riser was carried out with different excitation water depths in the wave-current combined water flume.By dimensionally changing the multi-stage water depth and hydrody... The vortex-induced vibration test of the deep-sea riser was carried out with different excitation water depths in the wave-current combined water flume.By dimensionally changing the multi-stage water depth and hydrodynamic parameters such as outflow velocity at various water depths,the dynamic response parameters such as dominant frequency,dimensionless displacement and vibration trajectory evolution process of the riser under different excitation water depths were explored to reveal the sensitive characteristics of the dynamic response of vortexinduced vibration of the risers under different excitation water depths.The results show that different excitation water depths will change the additional mass of the riser and the fluid damping and other parameters,which will affect the spatial correlation and stability of the vortex shedding behind the riser.In the lock-in region,the distribution range of the characteristic frequency becomes narrow and centered on the lock-in frequency.The increase of the excitation water depth gradually advances the starting point of the lock-in region of the riser,and at the same time promotes the excitation of the higher-order vibration frequency of the riser structure.Within the dimensionless excitation water depth,the dominant frequency and dimensionless displacement are highly insensitive to the excitation water depth at high flow velocity.The change of the excitation water depth will interfere with the correlation of the non-linear coupling of the riser.The“8-shaped”gradually becomes irregular,and the vibration trajectories of the riser show“O-shape”,“X-shape”and“Crescent-shape”. 展开更多
关键词 deep-sea riser excitation water depth vortex-induced vibration(VIV) dynamic response coupling effect
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Effects of water and nitrogen coupling on growth,physiology and yield of rice 被引量:2
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作者 Yuanyuan Li Xiaohou Shao +3 位作者 Daoxi Li Menghua Xiao Xiujun Hu Jing He 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2019年第3期60-66,共7页
Water and nitrogen fertilizer are two essential factors for quality and yield formation of rice.Experimental study was carried out to investigate the effects of water and nitrogen fertilizer coupling on yield-related ... Water and nitrogen fertilizer are two essential factors for quality and yield formation of rice.Experimental study was carried out to investigate the effects of water and nitrogen fertilizer coupling on yield-related factors,such as growth(height),physiological indicators(chlorophyll and leaf area index(LAI))and yield composition indicators(productive panicles,thousand grain weight and total grains per panicle).Results showed that,the height difference under two irrigation regimes was not significant,and it showed no difference until the tillering stage(p>0.05).The water control method for controlled and mid-gathering irrigation(CMI)was favorable for nutrients converting to rice grain.Meanwhile the height difference for CMI and conventional irrigation(CVI)was the biggest at 80 d after rice transplantation.Variance analysis showed the effect of fertilization on height was significant(p<0.05).With organic fertilizer application,it could control plant growth and promote the nutrients converting to the panicle.The change curve of LAI was similar to chlorophyll content.Organic fertilizer application could not only promote chlorophyll content and LAI,but also delay leaf fading and promote yield.Nitrogen fertilizer factors showed significant difference on rice yield,compared to irrigation regimes showing no significance.Considering the irrigation and fertilizer factors together,the interaction was significant.The descending orders for the effects of water and nitrogen on rice yield were fertilizer,water and fertilizer,water.Regression analysis showed that the productive panicles and total grains per panicle of rice were extremely significant on rice yield,and the direct effect of total grains per panicle on yield was greater than that of productive panicle.This study results could provide theoretical basis for water and nitrogen management to improve rice production. 展开更多
关键词 water and nitrogen coupling controlled and mid-gathering irrigation(CMI) organic fertilizer growth and physiology regression and path analysis rice yield
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Tidal effects on temperature iront in the Yellow Sea 被引量:6
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作者 马建 乔方利 +1 位作者 夏长水 杨永增 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第3期314-321,共8页
Temperature front (TF) is one of the important features in the Yellow Sea, which forms in spring,thrives in summer, and fades in autumn as thermocline declines. TF intensity |ST| is defined to describe the distributio... Temperature front (TF) is one of the important features in the Yellow Sea, which forms in spring,thrives in summer, and fades in autumn as thermocline declines. TF intensity |ST| is defined to describe the distribution of TF. Based on the MASNUM wave-tide-circulation coupled model, temperature distribution in the Yellow Sea was simulated with and without tidal effects. Along 36°N, distribution of TF from the simulated results are compared with the observations, and a quantitative analysis is introduced to evaluate the tidal effects on the forming and maintaining processes of the TF. Tidal mixing and the circulation structure adapting to it are the main causes of the TF. 展开更多
关键词 temperature front tidal effects tidal mixing wave-tide-circulation coupled model Yellow Sea Cold water Mass
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g-C3N4/SnS2 Heterostructure: a Promising Water Splitting Photocatalyst
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作者 Shao-hua Chen Jia-jun Wang +1 位作者 Jing Huang Qun-xiang Li 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第1期36-42,I0001,共8页
Graphite-like carbon nitride (g-C3N4) based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic str... Graphite-like carbon nitride (g-C3N4) based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic structures and optical absorption of the proposed g-CaN4/SnS2 heterostructure through performing extensive hybrid functional calculations. The obtained geometric structure, band structures, band edge positions and optical absorptions clearly reveal that the g-C3N4 monolayer weakly couples to SnS2 sheet, and forms a typical van der Waals heterojunction. The g-C3N4/SnS2 heterostructure can effectively harvest visible light, and its valence band maximum and conduction band minimum locate in energetically favorable positions for both water oxidation and reduction reactions. Remarkably, the charge transfer from the g-C3N4 monolayer to SnS2 sheet leads to the built-in interface polarized electric field, which is desirable for the photogenerated carrier separation. The built-in interface polarized electric field as well as the nice band edge alignment implys that the g-CaN4/SnS2 heterostructure is a promising g-CaN4 based water splitting photocatalyst with good performance. 展开更多
关键词 First-principles calculation coupling effect Optical absorption Band edge alignment water splitting
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水肥耦合对娃娃菜叶球养分吸收和土壤理化性质的影响
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作者 马彦霞 陈静茹 +4 位作者 王晓巍 张玉鑫 蒯佳琳 张莉 任亚丽 《干旱地区农业研究》 CSCD 北大核心 2024年第6期131-139,共9页
为探明河西冷凉灌区秋茬娃娃菜节水节肥、高产高效的科学灌溉施肥制度,以‘金皇后’为试材,研究了膜下滴灌条件下3个灌溉水平:60%θ_(f)(低水,H1)、70%θ_(f)(中水,H2)、80%θ_(f)(高水,H3)和3个施肥水平:N 281-P_(2)O_(5)166-K_(2)O 38... 为探明河西冷凉灌区秋茬娃娃菜节水节肥、高产高效的科学灌溉施肥制度,以‘金皇后’为试材,研究了膜下滴灌条件下3个灌溉水平:60%θ_(f)(低水,H1)、70%θ_(f)(中水,H2)、80%θ_(f)(高水,H3)和3个施肥水平:N 281-P_(2)O_(5)166-K_(2)O 383 kg·hm^(-2)(低肥,F1)、N 330-P_(2)O_(5)195-K_(2)O 450 kg·hm^(-2)(中肥,F2)、N 380-P_(2)O_(5)224-K_(2)O 518 kg·hm^(-2)(高肥,F3)组合对娃娃菜叶球养分吸收和土壤理化性质的影响。结果表明:水肥用量与娃娃菜田土壤理化性质和叶球氮磷钾吸收量关系密切,H2F2处理可在一定程度上改善娃娃菜田土壤的理化性质,维持土壤酸碱平衡,提高叶球养分含量,增加养分累积量。水肥耦合模式下,H2F2处理较H3F3处理娃娃菜叶球氮、磷、钾吸收量分别提高4.72%、3.26%、3.22%。H2F2处理水平下基于隶属函数与标准差系数权重法取得的水肥耦合效应综合得分最高,且较H3F3处理提高7.13%。综合考虑娃娃菜田土壤理化性质和叶球氮磷钾吸收量,灌水下限控制在70%θf、施肥量N 330-P_(2)O_(5)195-K_(2)O 450 kg·hm^(-2)是适合甘肃河西走廊冷凉灌区露地膜下滴灌秋茬娃娃菜最优的水肥管理模式。 展开更多
关键词 娃娃菜 水肥耦合 养分吸收 土壤理化性质
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保水剂和蒸腾抑制剂对玉米生长和水肥耦合的影响
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作者 佟长福 侯洪飞 +4 位作者 李瑞平 郑和祥 田小强 高海波 苗怀仁 《节水灌溉》 北大核心 2024年第6期63-68,76,共7页
保水剂和蒸腾抑制剂的应用对玉米高效生产发挥着重要作用。为探究保水剂和蒸腾抑制剂对玉米生长和土壤水肥耦合的影响,在内蒙古自治区鄂尔多斯市乌审旗河南乡小石砭村进行田间试验。试验共设置4个处理,分别为灌水定额为30 mm并且施加保... 保水剂和蒸腾抑制剂的应用对玉米高效生产发挥着重要作用。为探究保水剂和蒸腾抑制剂对玉米生长和土壤水肥耦合的影响,在内蒙古自治区鄂尔多斯市乌审旗河南乡小石砭村进行田间试验。试验共设置4个处理,分别为灌水定额为30 mm并且施加保水剂(C1)、灌水定额为37.5 mm并且施加保水剂(C2)、灌水定额为45 mm并且施加蒸腾抑制剂(C3)和灌水定额为45 mm并且不施加试剂(CK)。结果表明:①保水剂和蒸腾抑制剂能有效提升土壤保水能力,与CK相比,C1、C2和C3处理下玉米生育期平均土壤含水率分别提升6.61%、11.94%和4.05%。②保水剂和蒸腾抑制剂能有效提升玉米株高,其中拔节期玉米株高提升率最高,C1、C2和C3较CK分别提升9.40%、17.45%和6.04%。③玉米的茎粗随着生育期的推进呈现出先快速增长后缓慢增长再略微减小的趋势,快速增长期为拔节期,拔节期相比于苗期茎粗平均增长率为60.21%。④保水剂的施加可以增加土壤肥力和土壤水肥之间的协同关系,C2相比于CK土壤全氮、有效磷、速效钾、缓效钾和有机质含量分别增加37.57%、82.76%、88.66%、1.31%和37.83%;土壤水肥耦合度和耦合协调度分别增加77.74%和52.79%。综上所述,施加保水剂和蒸腾抑制剂可有效改善土壤水分状况,促进玉米生长发育,较不施加任何试剂的处理有明显优势。 展开更多
关键词 保水剂 蒸腾抑制剂 玉米生长 水肥耦合 协同 土壤含水率
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生物质缓释土壤保水增肥剂对宁夏盐池县土壤及其作物的影响
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作者 武金龙 李郝琪 +5 位作者 马锋茂 韩凤兰 黄家和 刘燕华 邵自强 江成云 《中国土壤与肥料》 CAS CSCD 北大核心 2024年第7期129-134,共6页
为探讨生物质缓释土壤保水增肥剂对农田土壤水温环境、土壤养分吸收和作物产量的影响,在宁夏回族自治区吴忠市盐池县以玉米、马铃薯、燕麦等为供试作物,生物质缓释土壤保水增肥剂为供试材料,采用田间试验,设置生物质缓释土壤保水增肥剂... 为探讨生物质缓释土壤保水增肥剂对农田土壤水温环境、土壤养分吸收和作物产量的影响,在宁夏回族自治区吴忠市盐池县以玉米、马铃薯、燕麦等为供试作物,生物质缓释土壤保水增肥剂为供试材料,采用田间试验,设置生物质缓释土壤保水增肥剂不同梯度的施用量,测定土壤含水量、酸碱度、电导率、容重和土壤养分等,研究其对试验地区土壤理化性质、土壤养分以及不同作物产量的影响。结果表明:在施用量不同的情况下,所种植的作物总体上产量都有所增加。苏丹草和燕麦草增产率最高,分别达到36.26%和24.35%。荞麦在生物质缓释土壤保水增肥剂施用量为120kg/hm^(2)时产量增产率达到23.19%,而马铃薯在生物质缓释土壤保水增肥剂施用量为120kg/hm^(2)时产量增产率最高,达到了77.78%,增产效果显著。但玉米产量变化趋势有所不同,在生物质缓释土壤保水增肥剂施用量为60kg/hm^(2)时产量反而有所下降,当施用量增加至120kg/hm^(2)时产量有所上升,但增产率只有0.69%,主要是由于地块所处位置、地势以及土壤组分存在一定程度的差异性,导致生物质缓释土壤保水增肥剂施用量对玉米产量影响不大。 展开更多
关键词 羧甲基纤维素 农作物 产量 土壤性质 保水增肥作用
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