Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug deliv...Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.展开更多
The aim of the present work was to show the sustainability of fibrin sealant in releasing dexamethasone and adjust the protocol for clinical application of the novel method in the treatment of Meniere’s disease (MD) ...The aim of the present work was to show the sustainability of fibrin sealant in releasing dexamethasone and adjust the protocol for clinical application of the novel method in the treatment of Meniere’s disease (MD) and sudden sensorineural hearing loss (SSHL).Gelation occurred shortly after mixing dexamethasone-containing fibrinogen with thrombin.Dexamethasone was constantly released for at least 16 d at a stable level after 7d in protocol 1 (low-dose),while it was robustly released within 4 d and slowed afterward until 10 d in protocol 2(high-dose).There were significant differences among the time points in Protocol 2 (p<0.01,ANOVA),and the exponential model with the formula y=15.299*e~(-0.483*t) fits the association.The estimated concentration of dexamethasone released on 7 d in protocol 2 was slightly lower than that observed in protocol 1.The fibrin sealant is capable of constantly releasing dexamethasone with adjustable dynamics.Targeted and minimally invasive administration of the material can be achieved in the clinic by sequential injections of the fluids using a soft-tipped catheter.展开更多
[Objective] This study aimed to explore the effects of continuous application of controlled release nitrogen fertilizer under double rice cropping system. [Method] By modeling three types of paddy soils in Dong-Ting L...[Objective] This study aimed to explore the effects of continuous application of controlled release nitrogen fertilizer under double rice cropping system. [Method] By modeling three types of paddy soils in Dong-Ting Lake area, four treatments as no fertilizer (CK), urea, controlled release nitrogen fertilizer (CRNF) and 70% controlled release nitrogen fertilizer (70% CRNF) were designed in the micro-plot trials from 2005 to 2008. [Result] The rice yield in treatment CRNF at N 150 kg/hm2 was increased by 10.3%, 8.0% and 2.4% compared with treatment of urea, in alluvial sandy loamy paddy soil (ALS), purple calcareous clayey paddy soil (PCS), and reddish yellow loamy paddy soil (RYS), respectively; and the yield in treatment of 70% CRNF was increased by 6.1%, 2.6% and -0.8%, respectively. The ranking order of nitrogen uptake amount by plant in early rice and late rice was CRNF 70% CRNF urea CK in all three types of soil. Nitrogen utilization efficiency of CRNF in above three types of soil was 60.7%, 59.6% and 56.3%, increased by 23.8%, 19.4% and 16.3% compared with that in treatment of urea, respectively. Nitrogen utilization efficiency of CRNF in early rice was increased year by year, and was higher than that of 70% CRNF during the whole experiment stage, while that in late rice was increased first and then decreased from the 3rd year. [Conclusion] Continuous application CRNF could alleviate the decreasing of soil nitrogen fertility and organic carbon especially in ALS, increase rice yield and nitrogen utilization efficiency in double-rice cropping system.展开更多
The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery...The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.展开更多
Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous ca...Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous carbon(BC)was developed to overcome the drawback of Eo.New composite materials were prepared by loading Eo on tea stem porous carbon(BC@Eo),and their controlled-release fungicidal activity against Exobasidium vexans was assessed.BC with a large specific surface area of 1001.6 m2/g and mesoporous structure was fabricated through carbonization tempera-ture of 700℃.The BC@Eo materials were characterized using Fourier-transform infrared spectroscopy and X-ray powder diffraction.The results suggested that chemical and physical interactions occurred in BC@Eo.The Eo release profile suggested a biphasic pattern with an initial fast release on days 1–14 and a subsequent controlled phase on days 14–30.The in vitro cumulative release percentage of Eo from BC@Eo was 51%during one month,and this result was significantly lower than that from free Eo(cumulative release percentage of Eo of 82%in one week).The anti-fungal activities of Eo and BC@Eo against E.vexans were determined using the inhibition zone method.The results indicated that Eo and BC@Eo formed large inhibition zones of 19.66±0.79 and 21.92±0.77 mm,respectively.The influence on the hyphal structure of E.vexans was observed by scanning electron microscopy on day 30.The hyphal structure of E.vexans treated with BC@Eo was more shrunken than that treated with Eo at 30 days,suggesting that BC@Eo prolongs the fungicidal activity against E.vexans.This study demonstrated that the encapsulation of Eo in BC for developing the BC@Eo materials could be a promising strategy to inhibit volatility and maintain the fungicidal activity of Eo and provide a potential alternative for the reuse of abundant tea biomass waste resources.展开更多
Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduce...Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea(CU). However, the crucial factors influencing the responses of NH3and N2O emissions to CRU relative to CU are still unclear. In this study, we evaluated the responses of NH3and N2O emissions to CRU based on collected field data with a meta-analysis. CRU reduced the NH3and N2O emissions by 32.7 and 25.0% compared with CU, respectively. According to subgroup analysis, CRU presented better mitigation of NH3and N2O emissions in soils with pH 6.5–7.5(–47.9 and –23.7%) relative to either pH<6.5(–28.5and –21.4%) or pH>7.5(–29.3 and –17.3%), and in the rice season(–34.8 and –29.1%) relative to the wheat season(–19.8 and –22.8%). The responses of NH3and N2O emissions to CRU increased from rainfed(–30.5 and –17.0%) to irrigated(–32.5 and –22.9%), and then to paddy(–34.8 and –29.1%) systems. In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen(TN);however, soil TN did not significantly affect the response of NH3volatilization. The reduction in NH3emission was greater in sandy-textured soil(–57.7%) relative to loam-textured(–32.9%) and clay-textured(–32.3%) soils, whereas soil texture did not affect N2O emission. Overall, CRU was a good option for reducing the NH3and N2O emissions relative to CU in agricultural production. This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE.展开更多
Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide (NIPAM) with silane-modified halloysite nanot...Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide (NIPAM) with silane-modified halloysite nanotubes (HNT) through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature (LCST), drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.展开更多
[Objectives]To study the effects of different proportions of controlled release urea and ordinary urea on peanut yield.[Methods]A total of 5 treatments were set up according to different proportions of controlled rele...[Objectives]To study the effects of different proportions of controlled release urea and ordinary urea on peanut yield.[Methods]A total of 5 treatments were set up according to different proportions of controlled release urea and ordinary urea,randomly arranged in blocks and repeated 3 times.[Results]The test results of field districts showed that different proportions of controlled release urea and conventional urea had different effects on peanut yield.On the basis of applying 50 kg/666.7 m^(2)of calcium superphosphate and 17 kg/666.7 m^(2)of potassium sulfate,13.34 kg/666.7 m^(2)of pure nitrogen was applied.The optimal ratio of controlled release urea to ordinary urea was 75:25,followed by 50:50.The output was 379.83 and 371.83 kg/666.7 m^(2),separately increased by 6.74%and 4.50%compared to the application of ordinary urea.[Conclusions]The combined application of controlled release urea and ordinary urea in peanuts can significantly increase peanut yield compared to just applying ordinary urea.展开更多
To achieve the controllable release of energy of nitrocellulose-based propellants,this paper combines the cellulose-based nanocomposites aqueous coating(Surelease®-NC)with fluidized bed coating equipment to succe...To achieve the controllable release of energy of nitrocellulose-based propellants,this paper combines the cellulose-based nanocomposites aqueous coating(Surelease®-NC)with fluidized bed coating equipment to successfully prepare the coated spherical propellant for the first time.The effects of fluidized bed coating temperature,air velocity,flow speed and atomization pressure on the adhesion rate,coating integrity and coating uniformity of the coated spherical propellant were investigated,and the preparation of coated spherical propellant with homogeneous size and structural integrity was achieved for the first time.The microscopic morphology,chemical structure,water vapor adsorption behavior,combustion performance,and ageing resistance property of the coated spherical propellant were systematically investigated by,Fourier transforms infrared spectroscopy(FTIR),Micro confocal raman spectrometer,field scanning electron microscopy(SEM),dynamic vapor adsorption techniques,and closed bomb test,confirming the surface core-shell structure and the tightly bonded interfacial structure of coated spherical propellant.Meanwhile,the coated spherical propellant has good hygroscopic,excellent progressive burning and long storage stability.展开更多
By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out...By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out in average speed of about 0.4%/d and 32% totally in 80 d compared with common compound fertUizer. For YZS80, in the vertical downward direction of application points, urea nitrogen content increased significantly (P 〈0.05) in the 45 -80 d and the 30 -60 cm soil layers; nitrate nitrogen content was little change range and in moderate (10 -100 mg/kg) in 0 -80 d and 10 -60 cm soil layers, but increased significantly ( P 〈0.05) 45 -80 d compared to 0 -45 d; ammonium nitrogen content was significant lower (P〈0.05) before 45 d in 10 -30 cm soil layers, but significant higher(P〈0.05) after 45 d in 10 -60 cm soil layers; NO3^- -N/NH4^+ -N meets gradually the needs of the crop with the extension of time. Under the co-situs application mode, the possibility of burning root and salt injury and loss dsk of nitrate leaching is a significant reduction.展开更多
[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei ho...[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei hot pepper(Capsicum frutescens L.)as the experimental material,we studied the fertilization effect and environment-protecting effect of SCRF.[Result] The result showed that SCRF could improve the agronomic characteristics of hot pepper.Compared to singly applied common fertilizers,SCRF increased economic yield by 20.90% and economic benefit by 13 234.35 Yuan/hm2,and the ratio of output to input was improved by 47.93%.In comparison with common straight fertilizers at same NPK proportion and rate,SCRF increased economic yield by 5.26% and economic benefit by 5 554.80 Yuan/hm2,and the ratio of output to input was improved by 9.91%.Under the reduced use of SCRF by 20%,SCRF increased economic yield by 12.38% and economic benefit by 9595.20 Yuan/hm2 compared with singly applied common fertilizers,and the ratio of output to input was improved by 65.95%.SCRF improved nitrogen,phosphorus and potassium use efficiencies by 12.42-17.53,3.35-5.24 and 5.37-14.02 percents respectively.[Conclusion] As the result of much reduced N and P application rates,SCRF would significantly economize fertilizer resources and minimize the pollution caused by the loss of fertilizer nutrients,which is of practical importance for environment protection.展开更多
[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fe...[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fertilizers were applied once at sowing summer maize to explore effects on maize growth, yield, economic profits and environment. [Result] Maize yield reduced a little in the treatment group with 60% CRF, and increased in varying degrees in the rest groups in the range of 1.1%-7.4%, and some showed significant differences. [Conclusion] Controlled-release fertilizers can be applied once at the amount of 80% common fertilizer's, with con- sideration of maize yield, nitrogen use rate and economic profits, which is beneficial for summer maize application and promotion in North China.展开更多
Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRN...Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRNF) on reco very and nitrate leaching on paddy soils. During two early rice cropping seasons (2002 and 2003), a single basal application of CRNF at 90 kg N ha-1 increased grain yields by 7.7%to 11.6%compared with two applications of urea. Estimated by the difference method fertilizer N recovery of CRNF (mean 76.3%) was 38.9 pe rcentage point higher than that of urea (mean 37.4%); estimated by 15N isotope method (mean 49.6%) CRNF (mean 67.1%) was 35.9 percentage point higher than ur ea (mean 31.2%). NO3--N leaching losses were 9.19 and 6.70 kg ha-1 for urea and CRNF, respectively. NO3--N leaching during the early rice cropping season was 27.1 %lower from CRNF than from two applications of urea. These losses repr esent 10.2%and 7.4%of applied urea-N and CRNF-N. Results from this study ind icate that CRNF improves N recovery and reduces NO3--N leaching and increases rice yield.展开更多
[Objective] The aim was to study on effects of controlled release fertilizer on loss of nitrogen and phosphorus from farmland. [Method] Experiment was conducted in fields planted with rice and corn around Chao Lake an...[Objective] The aim was to study on effects of controlled release fertilizer on loss of nitrogen and phosphorus from farmland. [Method] Experiment was conducted in fields planted with rice and corn around Chao Lake and effects of compound fertilizer, controlled release fertilizer and controlled release fertilizer (reduced by 20%) on loss of nitrogen and phosphorus through runoff and leaching were analyzed. [Result] Loss of nitrogen and phosphorus mainly occurred in early stage of fertilizing; loss caused by runoff accounted for over 98% and caused by leaching was lower than 2%, indicating that nutrients of rice and corn mainly lost through runoff. As for controlled release fertilizers with 20% reduced, total loss of N and P decreased by 60% and 63% in rice field and reduced by 27.8% and 34% in corn field, respectively, indicating that controlled release fertilizer would maintain nutrients in soils high in later period of plant growth, improve use efficiency of N and P, reduce N and P loss in rice and corn fields in rainy season, and decrease non-point pollution. [Conclusion] The research suggested that controlled release fertilizer would slow down the loss of nutrients in farmlands, providing scientific references and technological support for extension of controlled release fertilizer and reduction of agricultural non-point pollution.展开更多
Different application rates of controlled release nitrogen fertilizer (CRFN) were designed to evaluate their effects on the growth and root morphology of bitter gourd (Momordica charantia L.) seedlings, and thus d...Different application rates of controlled release nitrogen fertilizer (CRFN) were designed to evaluate their effects on the growth and root morphology of bitter gourd (Momordica charantia L.) seedlings, and thus determine the optimal nitrogen amount and suitable nitrogen content in substrate at seedling transplanting,, in com- parison with conventional fertilizer application. CRFN was applied at five levels, 0, 0.6, 1.2, 2.4 and 4.8 kg N/m3, and conventional fertilizer was applied at 0.6 kg N/m3 as control. Four replicates were included in each treatment. The results showed that 0.6-2.4 kg N/m3 CRFN provided sufficient N nutrient for bitter gourd, with higher shoot and root dry weights, root length and root surface area than control treat- ments. Correspondingly, the total inorganic nitrogen in substrate ranged from 99.3 to 162.5 mg/pot at seedling transplanting in these treatments. 1.2 kg N/m3 was proven to be the optimal CRFN rate. Compared with conventional nitrogen fertilizer applica- tion, 1.2 kg N/m3 CRFN in substrate increased the dry weight, nitrogen uptake and improved root morphology indices of seedlings, and more than 83.3 mg/pot inorgan- ic nitrogen could be carried with substrate at transplanting, revealing a potential to reduce N-deficient risk after rain and basal N input by continuous release of CRFN.展开更多
The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicat...The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.展开更多
[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers (CRFs) on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to i...[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers (CRFs) on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer (CF). [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time (CF1), and 19.6% and 15.4% with CF application at two times (CF2), respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.展开更多
[Objective] Effects of controlled release N fertilizers on wheat growth and yield were studied to provide reference for the application of controlled release fertilizers on wheat. [Method] A field experiment was condu...[Objective] Effects of controlled release N fertilizers on wheat growth and yield were studied to provide reference for the application of controlled release fertilizers on wheat. [Method] A field experiment was conducted to study the effects of different types and levels of controlled release N fertilizers on the growth and yield of wheat. In this experiment, a treatment with the application of common urea and potassium chloride(common fertilizer) was established, and treatments with controlled release N fertilizers A and B with different coating materials were also established. [Result] The results showed that under the condition of the same P and K levels, controlled release N fertilizer A at a proportion of 100%, controlled release N fertilizer A at a proportion of 80% and controlled release N fertilizer B at a proportion of 80% could promote wheat growth, optimize yield components, and increase the amount of dry matter accumulation and grain yield. [Conclusion] One-time application of controlled release N fertilizer could be adopted in wheat production to achieve the purposes of saving fertilizer, saving labor and increasing efficiency.展开更多
In order to study the effects of controlled release nitrogen fertilizer (CRNF) application on rapeseed, a simulated experiment was carried out with 3 types of paddy soils in Dongting Lake area for 4 consecutive year...In order to study the effects of controlled release nitrogen fertilizer (CRNF) application on rapeseed, a simulated experiment was carried out with 3 types of paddy soils in Dongting Lake area for 4 consecutive years of applying CRNF under double rice cropping system after planting rapeseed crop in the fallow season. The effects of CRNF application on rapeseed yield, agronomic characters and soil fertility were studied in this paper. The results showed that CRNF application improved the growth of rapeseed plant and increased rapeseed yield of CRNF treatments in the purple calcareous clayed paddy soil (PCS) and alluvial loamy paddy soil (ALS) which respectively increased by 12.2% and 9.8% compared with applying urea, re- spectively. The rapeseed yield in 70% CRNF treatment obviously decreased com- pared with urea treatment. The contents of available N and organic carbon in soil increased by 25.0% and 3.2% in CRNF treatment in the ALS after rapeseed crop, respectively; and available N increased by 13.5% in the PCS. Both rapeseed yield and soil fertility in CRNF treatment and 70% CRNF treatment were lower than those in CK treatment in the reddish yellow clayed paddy soil (RYS). The results al- so indicated that the functions of CRNF application on rapeseed yield increase and soil nitrogen fertility improvement were very obvious in the PCS and ALS.展开更多
A light and temperature dual responsive copolymer,poly(7-(4-vinylbenzy-loxyl)-4-methylcoumarin-co-N vinyl caprolactam-co-tri(ethylene glycol)methyl ether methacrylate)(PVNM),was grafted on the surface of dopamine base...A light and temperature dual responsive copolymer,poly(7-(4-vinylbenzy-loxyl)-4-methylcoumarin-co-N vinyl caprolactam-co-tri(ethylene glycol)methyl ether methacrylate)(PVNM),was grafted on the surface of dopamine based mesoporous silica nanoparticles(MSNs).The resulting polymer brush,MSNs-g-PVNM,was characterized by FT-IR,TEM,TGA and XPS.The dual responsive behaviors of MSNs-g-PVNM were systematically studied.With imidacloprid as the model guest pesticide,the loading percentage and loading efficiency of the polymer brush were determined as 9.2%and 40.6%,respectively.The release efficiency of imidacloprid in MSNs-g-PVNM was the lowest value of 5.4%at 20℃ and 365 nm,and it reached the highest value of 52.4%at 50℃ and 254 nm.The loss percentage of imidacloprid on the leaves contained imidacloprid-loaded MSNs-g-PVNM(8.4%)was much less than that contained only imidacloprid(25.2%)after three rinses.It was confirmed that the release process of imidacloprid was well regulated through changing external conditions such as light and temperature.展开更多
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2023MC168the National Natural Science Foundation of China,No.31670989the Key R&D Program of Shandong Province,No.2019GSF107037(all to CS).
文摘Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China(81771006)。
文摘The aim of the present work was to show the sustainability of fibrin sealant in releasing dexamethasone and adjust the protocol for clinical application of the novel method in the treatment of Meniere’s disease (MD) and sudden sensorineural hearing loss (SSHL).Gelation occurred shortly after mixing dexamethasone-containing fibrinogen with thrombin.Dexamethasone was constantly released for at least 16 d at a stable level after 7d in protocol 1 (low-dose),while it was robustly released within 4 d and slowed afterward until 10 d in protocol 2(high-dose).There were significant differences among the time points in Protocol 2 (p<0.01,ANOVA),and the exponential model with the formula y=15.299*e~(-0.483*t) fits the association.The estimated concentration of dexamethasone released on 7 d in protocol 2 was slightly lower than that observed in protocol 1.The fibrin sealant is capable of constantly releasing dexamethasone with adjustable dynamics.Targeted and minimally invasive administration of the material can be achieved in the clinic by sequential injections of the fluids using a soft-tipped catheter.
基金Supported by the National Key Technology Research and Development Program of China during the11th Five-Year Plan Period(2008BADA4B08)Science and Technology Innovation Project of Hunan Academy of Agricultural Sciences(2010hnnkycx56)~~
文摘[Objective] This study aimed to explore the effects of continuous application of controlled release nitrogen fertilizer under double rice cropping system. [Method] By modeling three types of paddy soils in Dong-Ting Lake area, four treatments as no fertilizer (CK), urea, controlled release nitrogen fertilizer (CRNF) and 70% controlled release nitrogen fertilizer (70% CRNF) were designed in the micro-plot trials from 2005 to 2008. [Result] The rice yield in treatment CRNF at N 150 kg/hm2 was increased by 10.3%, 8.0% and 2.4% compared with treatment of urea, in alluvial sandy loamy paddy soil (ALS), purple calcareous clayey paddy soil (PCS), and reddish yellow loamy paddy soil (RYS), respectively; and the yield in treatment of 70% CRNF was increased by 6.1%, 2.6% and -0.8%, respectively. The ranking order of nitrogen uptake amount by plant in early rice and late rice was CRNF 70% CRNF urea CK in all three types of soil. Nitrogen utilization efficiency of CRNF in above three types of soil was 60.7%, 59.6% and 56.3%, increased by 23.8%, 19.4% and 16.3% compared with that in treatment of urea, respectively. Nitrogen utilization efficiency of CRNF in early rice was increased year by year, and was higher than that of 70% CRNF during the whole experiment stage, while that in late rice was increased first and then decreased from the 3rd year. [Conclusion] Continuous application CRNF could alleviate the decreasing of soil nitrogen fertility and organic carbon especially in ALS, increase rice yield and nitrogen utilization efficiency in double-rice cropping system.
基金This work was funded by the National Natural Science Foundation of China(31871573)the Key Research and Development Program of Jiangsu Province,China(BE2017369)the Jiangsu Agriculture Science and Technology Innovation Fund,China(JASTIF)(CX(18)1002).
文摘The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive,time consuming and laborious.The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings(TLMS)are necessary for the resource-efficient cultivation of rice.In the present study,a controlled-release fertilizer(CRF)-polymer-coated compound fertilizer with 3 months release period(PCCF-3M)was applied as seedling fertilizer(SF),and five different dosages of SF(SF-0,SF-10,SF-20,SF-30,and SF-40)were compared with an organic substrate as the control(CK).Among all SF treatments,the best results were obtained with the application of 20 g/tray of SF(SF-20),as the seedling quality and machine transplanting quality were comparable to those of CK.In contrast,the lower dosages(SF-0 and SF-10)resulted in low nitrogen content and reduced shoot growth,while the higher dosages(SF-30 and SF-40)resulted in toxicity(increased malondialdehyde accumulation)and inhibited the root growth.Similarly,SF-20 increased panicle number(5.6-7.0%)and yield(4.3-5.3%)compared with CK,which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field.Moreover,SF-20 reduced the seedling block weight(53.1%)and cost of seedling production(23.5%)but increased the gross margin,indicating that it was easy to handle and economical.Taken together,our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings.To our knowledge,this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.
基金Supported by National Modern Agricultural Industry Technology System,Youth Science and Technology Fund of Guizhou Academy of Agricultural Sciences No.[2020]02,Guiding Project of Guizhou Academy of Agricultural Sciences No.[2018]01.
文摘Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous carbon(BC)was developed to overcome the drawback of Eo.New composite materials were prepared by loading Eo on tea stem porous carbon(BC@Eo),and their controlled-release fungicidal activity against Exobasidium vexans was assessed.BC with a large specific surface area of 1001.6 m2/g and mesoporous structure was fabricated through carbonization tempera-ture of 700℃.The BC@Eo materials were characterized using Fourier-transform infrared spectroscopy and X-ray powder diffraction.The results suggested that chemical and physical interactions occurred in BC@Eo.The Eo release profile suggested a biphasic pattern with an initial fast release on days 1–14 and a subsequent controlled phase on days 14–30.The in vitro cumulative release percentage of Eo from BC@Eo was 51%during one month,and this result was significantly lower than that from free Eo(cumulative release percentage of Eo of 82%in one week).The anti-fungal activities of Eo and BC@Eo against E.vexans were determined using the inhibition zone method.The results indicated that Eo and BC@Eo formed large inhibition zones of 19.66±0.79 and 21.92±0.77 mm,respectively.The influence on the hyphal structure of E.vexans was observed by scanning electron microscopy on day 30.The hyphal structure of E.vexans treated with BC@Eo was more shrunken than that treated with Eo at 30 days,suggesting that BC@Eo prolongs the fungicidal activity against E.vexans.This study demonstrated that the encapsulation of Eo in BC for developing the BC@Eo materials could be a promising strategy to inhibit volatility and maintain the fungicidal activity of Eo and provide a potential alternative for the reuse of abundant tea biomass waste resources.
基金financially supported by the Smart Fertilization Project (05)the National Key Research & Development Program of China (2022YFD1700605)。
文摘Reducing ammonia(NH3) and nitrous oxide(N2O) emissions have great effects on mitigating nitrogen(N) nutrient loss and greenhouse gas emissions. Controlled release urea(CRU) can control the N release rate, which reduces reactive N loss and increases nitrogen use efficiency relative to conventional urea(CU). However, the crucial factors influencing the responses of NH3and N2O emissions to CRU relative to CU are still unclear. In this study, we evaluated the responses of NH3and N2O emissions to CRU based on collected field data with a meta-analysis. CRU reduced the NH3and N2O emissions by 32.7 and 25.0% compared with CU, respectively. According to subgroup analysis, CRU presented better mitigation of NH3and N2O emissions in soils with pH 6.5–7.5(–47.9 and –23.7%) relative to either pH<6.5(–28.5and –21.4%) or pH>7.5(–29.3 and –17.3%), and in the rice season(–34.8 and –29.1%) relative to the wheat season(–19.8 and –22.8%). The responses of NH3and N2O emissions to CRU increased from rainfed(–30.5 and –17.0%) to irrigated(–32.5 and –22.9%), and then to paddy(–34.8 and –29.1%) systems. In addition, the response of N2O emission mitigation increased with increases in soil total nitrogen(TN);however, soil TN did not significantly affect the response of NH3volatilization. The reduction in NH3emission was greater in sandy-textured soil(–57.7%) relative to loam-textured(–32.9%) and clay-textured(–32.3%) soils, whereas soil texture did not affect N2O emission. Overall, CRU was a good option for reducing the NH3and N2O emissions relative to CU in agricultural production. This analysis improves our understanding of the crucial environmental and management factors influencing the mitigation of NH3and N2O emissions under CRU application, and these site-specific factors should be considered when applying CRU to reduce reactive N loss and increase NUE.
基金Supported by the National ]qatural Science Foundation of China (20906064), the National Basic Research Program of China (2009CB623407), the Program for Changjiang Scholars and Innovative Research Team in University (IRTl163), and the Foundation for the Author of National Excellent Doctoral Dissertation of China (201163).
文摘Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide (NIPAM) with silane-modified halloysite nanotubes (HNT) through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature (LCST), drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.
基金Peanut Innovation Team Project of Shandong Province Modern Agricultural Industry Technology System(SDAIT-05-022)Special Fund Project of Shandong Province Agricultural Technology Promotion(SDTG-2016-08).
文摘[Objectives]To study the effects of different proportions of controlled release urea and ordinary urea on peanut yield.[Methods]A total of 5 treatments were set up according to different proportions of controlled release urea and ordinary urea,randomly arranged in blocks and repeated 3 times.[Results]The test results of field districts showed that different proportions of controlled release urea and conventional urea had different effects on peanut yield.On the basis of applying 50 kg/666.7 m^(2)of calcium superphosphate and 17 kg/666.7 m^(2)of potassium sulfate,13.34 kg/666.7 m^(2)of pure nitrogen was applied.The optimal ratio of controlled release urea to ordinary urea was 75:25,followed by 50:50.The output was 379.83 and 371.83 kg/666.7 m^(2),separately increased by 6.74%and 4.50%compared to the application of ordinary urea.[Conclusions]The combined application of controlled release urea and ordinary urea in peanuts can significantly increase peanut yield compared to just applying ordinary urea.
基金supported by the National Natural Science Foundation of China (Grant No.22005143)Young Elite Scientists Sponsorship Program by CAST (Grant No.2022QNRC001)。
文摘To achieve the controllable release of energy of nitrocellulose-based propellants,this paper combines the cellulose-based nanocomposites aqueous coating(Surelease®-NC)with fluidized bed coating equipment to successfully prepare the coated spherical propellant for the first time.The effects of fluidized bed coating temperature,air velocity,flow speed and atomization pressure on the adhesion rate,coating integrity and coating uniformity of the coated spherical propellant were investigated,and the preparation of coated spherical propellant with homogeneous size and structural integrity was achieved for the first time.The microscopic morphology,chemical structure,water vapor adsorption behavior,combustion performance,and ageing resistance property of the coated spherical propellant were systematically investigated by,Fourier transforms infrared spectroscopy(FTIR),Micro confocal raman spectrometer,field scanning electron microscopy(SEM),dynamic vapor adsorption techniques,and closed bomb test,confirming the surface core-shell structure and the tightly bonded interfacial structure of coated spherical propellant.Meanwhile,the coated spherical propellant has good hygroscopic,excellent progressive burning and long storage stability.
基金Supported by Beijing Science Committee Project"Science & TechnologyNew Star"(2008B38)"The Research and Establishmentof Agrochemical Service System for New Type of Fertilizer"(d0706004040431)The Foundation for Youth Scholars of BeijingAcademy of Agriculture and Forestry Sciences"The Developmentand Evaluation of Micro Water-soluble Cementation Coated Slow-releaseFertilizers Suitable for Semiand Areas"~~
文摘By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out in average speed of about 0.4%/d and 32% totally in 80 d compared with common compound fertUizer. For YZS80, in the vertical downward direction of application points, urea nitrogen content increased significantly (P 〈0.05) in the 45 -80 d and the 30 -60 cm soil layers; nitrate nitrogen content was little change range and in moderate (10 -100 mg/kg) in 0 -80 d and 10 -60 cm soil layers, but increased significantly ( P 〈0.05) 45 -80 d compared to 0 -45 d; ammonium nitrogen content was significant lower (P〈0.05) before 45 d in 10 -30 cm soil layers, but significant higher(P〈0.05) after 45 d in 10 -60 cm soil layers; NO3^- -N/NH4^+ -N meets gradually the needs of the crop with the extension of time. Under the co-situs application mode, the possibility of burning root and salt injury and loss dsk of nitrate leaching is a significant reduction.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest from Ministry of Agriculture(200903025-05)Fund from Kunming Municipal Science and Technology Committee(08S010201)~~
文摘[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei hot pepper(Capsicum frutescens L.)as the experimental material,we studied the fertilization effect and environment-protecting effect of SCRF.[Result] The result showed that SCRF could improve the agronomic characteristics of hot pepper.Compared to singly applied common fertilizers,SCRF increased economic yield by 20.90% and economic benefit by 13 234.35 Yuan/hm2,and the ratio of output to input was improved by 47.93%.In comparison with common straight fertilizers at same NPK proportion and rate,SCRF increased economic yield by 5.26% and economic benefit by 5 554.80 Yuan/hm2,and the ratio of output to input was improved by 9.91%.Under the reduced use of SCRF by 20%,SCRF increased economic yield by 12.38% and economic benefit by 9595.20 Yuan/hm2 compared with singly applied common fertilizers,and the ratio of output to input was improved by 65.95%.SCRF improved nitrogen,phosphorus and potassium use efficiencies by 12.42-17.53,3.35-5.24 and 5.37-14.02 percents respectively.[Conclusion] As the result of much reduced N and P application rates,SCRF would significantly economize fertilizer resources and minimize the pollution caused by the loss of fertilizer nutrients,which is of practical importance for environment protection.
基金Supported by S&T Development Plan Program of Shandong Province(2014GNC113001)State Key Laboratory for Biology of Crops(2014KF11)S&T Development Plan Program of Tai'an City~~
文摘[Objective] The aim was to select the optimal amount of controlled-release fertilizer and provide theoretical references for controlled-release fertilizers use in summer maize. [Method] Long-term controlled-release fertilizers were applied once at sowing summer maize to explore effects on maize growth, yield, economic profits and environment. [Result] Maize yield reduced a little in the treatment group with 60% CRF, and increased in varying degrees in the rest groups in the range of 1.1%-7.4%, and some showed significant differences. [Conclusion] Controlled-release fertilizers can be applied once at the amount of 80% common fertilizer's, with con- sideration of maize yield, nitrogen use rate and economic profits, which is beneficial for summer maize application and promotion in North China.
文摘Ordinary high nitrogen fertilizer often results in nitrate (NO3--N) leaching and low recovery. Microplot and field plot experiments were conducted to determine the effect of controlled release nitrogen fertilizer (CRNF) on reco very and nitrate leaching on paddy soils. During two early rice cropping seasons (2002 and 2003), a single basal application of CRNF at 90 kg N ha-1 increased grain yields by 7.7%to 11.6%compared with two applications of urea. Estimated by the difference method fertilizer N recovery of CRNF (mean 76.3%) was 38.9 pe rcentage point higher than that of urea (mean 37.4%); estimated by 15N isotope method (mean 49.6%) CRNF (mean 67.1%) was 35.9 percentage point higher than ur ea (mean 31.2%). NO3--N leaching losses were 9.19 and 6.70 kg ha-1 for urea and CRNF, respectively. NO3--N leaching during the early rice cropping season was 27.1 %lower from CRNF than from two applications of urea. These losses repr esent 10.2%and 7.4%of applied urea-N and CRNF-N. Results from this study ind icate that CRNF improves N recovery and reduces NO3--N leaching and increases rice yield.
基金Supported by Major Project of Control and Treatment on Domestic Water Pollution(2012ZX07103003)National 973 Project(2008CB418006)Science and Technology Foundation for Distinguished Young Schlors in Anhui Province(10040606Y30)~~
文摘[Objective] The aim was to study on effects of controlled release fertilizer on loss of nitrogen and phosphorus from farmland. [Method] Experiment was conducted in fields planted with rice and corn around Chao Lake and effects of compound fertilizer, controlled release fertilizer and controlled release fertilizer (reduced by 20%) on loss of nitrogen and phosphorus through runoff and leaching were analyzed. [Result] Loss of nitrogen and phosphorus mainly occurred in early stage of fertilizing; loss caused by runoff accounted for over 98% and caused by leaching was lower than 2%, indicating that nutrients of rice and corn mainly lost through runoff. As for controlled release fertilizers with 20% reduced, total loss of N and P decreased by 60% and 63% in rice field and reduced by 27.8% and 34% in corn field, respectively, indicating that controlled release fertilizer would maintain nutrients in soils high in later period of plant growth, improve use efficiency of N and P, reduce N and P loss in rice and corn fields in rainy season, and decrease non-point pollution. [Conclusion] The research suggested that controlled release fertilizer would slow down the loss of nutrients in farmlands, providing scientific references and technological support for extension of controlled release fertilizer and reduction of agricultural non-point pollution.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest of China(201503106,201103003)Earmarked Fund for China Agriculture Research System(CARS-25-G-36)~~
文摘Different application rates of controlled release nitrogen fertilizer (CRFN) were designed to evaluate their effects on the growth and root morphology of bitter gourd (Momordica charantia L.) seedlings, and thus determine the optimal nitrogen amount and suitable nitrogen content in substrate at seedling transplanting,, in com- parison with conventional fertilizer application. CRFN was applied at five levels, 0, 0.6, 1.2, 2.4 and 4.8 kg N/m3, and conventional fertilizer was applied at 0.6 kg N/m3 as control. Four replicates were included in each treatment. The results showed that 0.6-2.4 kg N/m3 CRFN provided sufficient N nutrient for bitter gourd, with higher shoot and root dry weights, root length and root surface area than control treat- ments. Correspondingly, the total inorganic nitrogen in substrate ranged from 99.3 to 162.5 mg/pot at seedling transplanting in these treatments. 1.2 kg N/m3 was proven to be the optimal CRFN rate. Compared with conventional nitrogen fertilizer applica- tion, 1.2 kg N/m3 CRFN in substrate increased the dry weight, nitrogen uptake and improved root morphology indices of seedlings, and more than 83.3 mg/pot inorgan- ic nitrogen could be carried with substrate at transplanting, revealing a potential to reduce N-deficient risk after rain and basal N input by continuous release of CRFN.
文摘The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.
基金Supported by the Effect and Mechanism of Gel-based Controlled Release Fertilizers on Controlling the Nutrient Loss in Soil Erosion (10501-291)Research and Demonstration of New Special Fertilizer for Seawater Fishes and Shellfish (2012-931)+1 种基金Key Techniques and Demonstration of Tobacco Controlled Release Fertilizer Industrialization (2012-045)Research and Application of Gel-based Controlled Release Fertilizers (2002N002)~~
文摘[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers (CRFs) on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer (CF). [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time (CF1), and 19.6% and 15.4% with CF application at two times (CF2), respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201203079,201503130)Science and Technology Development Project of Shandong Province(2014GNC113001,2014GNC112003)Science and Technology Development Project of Taian City(201440774-19B)~~
文摘[Objective] Effects of controlled release N fertilizers on wheat growth and yield were studied to provide reference for the application of controlled release fertilizers on wheat. [Method] A field experiment was conducted to study the effects of different types and levels of controlled release N fertilizers on the growth and yield of wheat. In this experiment, a treatment with the application of common urea and potassium chloride(common fertilizer) was established, and treatments with controlled release N fertilizers A and B with different coating materials were also established. [Result] The results showed that under the condition of the same P and K levels, controlled release N fertilizer A at a proportion of 100%, controlled release N fertilizer A at a proportion of 80% and controlled release N fertilizer B at a proportion of 80% could promote wheat growth, optimize yield components, and increase the amount of dry matter accumulation and grain yield. [Conclusion] One-time application of controlled release N fertilizer could be adopted in wheat production to achieve the purposes of saving fertilizer, saving labor and increasing efficiency.
基金Supported by National Key Technology R&D Program Project in the 12~(th) Five-Year Plan:The 3~(rd) Hunan Special Project of Grain Bumper Science and Technology "The Integration and Demonstration of High-yield,Water-saving and Fertilizer-saving Techniques in the South Rice Area of Middle Reaches of Yangtze"(2013BAD07B11)Agro-scientific Research Programs in Public Interest "Study on the Change of Soil Fertility and Fertility Techniques in the Major Grain Producing Areas and the Demonstration"(201203030)International Cooperation Project"Study on the Efficient Nutrient Management Technology of Modern Double Cropping Rice in Hunan Province"(IPNI Hunan-18)~~
文摘In order to study the effects of controlled release nitrogen fertilizer (CRNF) application on rapeseed, a simulated experiment was carried out with 3 types of paddy soils in Dongting Lake area for 4 consecutive years of applying CRNF under double rice cropping system after planting rapeseed crop in the fallow season. The effects of CRNF application on rapeseed yield, agronomic characters and soil fertility were studied in this paper. The results showed that CRNF application improved the growth of rapeseed plant and increased rapeseed yield of CRNF treatments in the purple calcareous clayed paddy soil (PCS) and alluvial loamy paddy soil (ALS) which respectively increased by 12.2% and 9.8% compared with applying urea, re- spectively. The rapeseed yield in 70% CRNF treatment obviously decreased com- pared with urea treatment. The contents of available N and organic carbon in soil increased by 25.0% and 3.2% in CRNF treatment in the ALS after rapeseed crop, respectively; and available N increased by 13.5% in the PCS. Both rapeseed yield and soil fertility in CRNF treatment and 70% CRNF treatment were lower than those in CK treatment in the reddish yellow clayed paddy soil (RYS). The results al- so indicated that the functions of CRNF application on rapeseed yield increase and soil nitrogen fertility improvement were very obvious in the PCS and ALS.
基金Project(21376271)supported by the National Natural Science Foundation of ChinaProject(2016TP1007)supported by the Hunan Provincial Science and Technology Plan Project,ChinaProjects(201810533078,S2020105330395)supported by the Undergraduates Innovative Training Foundation of Central South University,China。
文摘A light and temperature dual responsive copolymer,poly(7-(4-vinylbenzy-loxyl)-4-methylcoumarin-co-N vinyl caprolactam-co-tri(ethylene glycol)methyl ether methacrylate)(PVNM),was grafted on the surface of dopamine based mesoporous silica nanoparticles(MSNs).The resulting polymer brush,MSNs-g-PVNM,was characterized by FT-IR,TEM,TGA and XPS.The dual responsive behaviors of MSNs-g-PVNM were systematically studied.With imidacloprid as the model guest pesticide,the loading percentage and loading efficiency of the polymer brush were determined as 9.2%and 40.6%,respectively.The release efficiency of imidacloprid in MSNs-g-PVNM was the lowest value of 5.4%at 20℃ and 365 nm,and it reached the highest value of 52.4%at 50℃ and 254 nm.The loss percentage of imidacloprid on the leaves contained imidacloprid-loaded MSNs-g-PVNM(8.4%)was much less than that contained only imidacloprid(25.2%)after three rinses.It was confirmed that the release process of imidacloprid was well regulated through changing external conditions such as light and temperature.