Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembl...Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and photoinduced seeded reversible addition-fragmentation chain transfer(RAFT)polymerization to prepare a diverse set of core-shell colloidal particles with a well-defined polymer layer.Chemical compositions,structures,and thicknesses of polymer layers could be conveniently regulated by using different types of monomers and feed[monomer]/[chain transfer agent]ratios during seeded RAFT polymerization.展开更多
Rice direct seeding technology is an appealing alternative to traditional transplanting because it conserves labor and irrigation resources.Nevertheless,there are two main issues,salt stress and alkaline stress,which ...Rice direct seeding technology is an appealing alternative to traditional transplanting because it conserves labor and irrigation resources.Nevertheless,there are two main issues,salt stress and alkaline stress,which contribute to poor emergence and seedling growth,thereby preventing the widespread adoption and application of this technique in the Ningxia Region of China.Therefore,to determine whether germination can be promoted by mixed-oligosaccharide(KP)priming(in which seeds are soaked in a KP solution before sowing)under salt and alkaline stress,a proteomics study was performed.KP-priming significantly mitigated abiotic stress,such as salt and alkaline stress,by inhibiting root elongation,ultimately improving seedling establishment.By comparing the proteomics analyses,we found that energy metabolic pathway was a vital factor in KP-priming,which explains the alleviation of salt and alkaline stress.Key proteins involved in starch mobilization,pyruvate mobilization,and ATP synthesis,were up-regulated by KP-priming,significantly blocking salt and alkaline-triggered starch accumulation while enhancing pyruvate metabolism.KP-priming also up-regulated ATP synthase to improve energy efficiency,thereby improving ATP production.In addition,it enhanced antioxidant enzymatic activities and reduced the accumulation of reactive oxygen species.All of these factors contributed to a better understanding of the energy regulatory pathway enhanced by KP-priming,which mediated the promotion of growth under salt and alkaline conditions.Thus,this study demonstrated that KP-priming can improve rice seed germination under salt and alkaline stress by altering energy metabolism.展开更多
The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pai...The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al（OH）4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na＋Al（OH）4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation.展开更多
High soda content in fine alumina trihydrate（ATH） limits its application and increases the soda consumption. The variation of soda content in the fine ATH by seeded precipitation was determined by detection of elect...High soda content in fine alumina trihydrate（ATH） limits its application and increases the soda consumption. The variation of soda content in the fine ATH by seeded precipitation was determined by detection of electric conductivity of solution, soda content in ATH, measurement of particle size distribution and microscopic analysis. The results show that high concentration of sodium aluminate solution, ground circulative seed, low temperature or fast initial precipitation rate increases the soda content in ATH. Soda mainly exists in lattice soda and less soda in desilication product （DSP） exists in the fine ATH precipitated from sodium aluminate solution with concentration of Al2O3 （ρAl2O3） more than 160 g/L and mass ratio of alumina to silica （μSiO2） of 400, and lattice soda decreases with increasing initial precipitation temperature, aging seed, and low precipitation rate and precipitation time. Results also imply that -＋ 4）Na Al（OH ion-pair influences lattice soda content in ATH on the basis of electric conductivity variation.展开更多
The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa c...The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli （L.） Beauv and other gramineous weed control efficiency with four concentrations of 20% cyhalofop-dutyl WP and 100 g/L cyhalofop-dutyl EC in direct seeded rice fields, and analyzed the yield-increasing effect and safety of rice. The results showed that 20% cyhalofop-butyl WP had a good control efficiency on grass weeds such as Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli（L.） Beauv and other grasses. The effective dosage of 90-150 g/hm2 was over 90.7% on Lep- foch/oa chinensis（L.） Nees and the comprehensive control effect of the grass weeds was above 86.7%, which was basically consistent with 100 g/L cyhalofop-dutyl EC. Furthermore, 20% cyhalofop-dutyl WP was high security for direct seeded rice fields. The yield of rice was increased by 10.18%-11.22% after spraying herbicide. There- fore, 20% of cyhalofop-dutyl WP can be used as a special herbicide for controlling Leptochloa chinensis（L.） Beauv in direct seeded rice fields, and has a good applica- tion prospect.展开更多
[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effect...[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effects were observed 5, 10, 15 and 30 d after drug application, with the remained weeds surveyed 15 and 30 d after drug application. [Result] The test showed pyrazosulfuron-ethyl·quinclorac 50%WP was safe to rice as treatment agent of stem and leaf, and rice yield increased dramatical y, with the growth rate in 2.1%-49.3%. After the drug application, the prevention effects on Echinochloa crusgal i, Ludwimlia prostrata, Monochoria vamli-nalis, and Zong grass were 92.2%, 96.6%, 93.5%, and 94.8%, and the effects on fresh weight were 94.8%, 97.1%, 93.3% and 94.9%, respectively. [Conclusion] Pyra-zosulfuron-ethyl·quinclorac 50% WP can be taken as treatment agents of stem and leaf of dry direct seeded rice.展开更多
Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice （DSR） has been considered as a replacement for traditional transplanted flooded rice （TFR）. However, th...Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice （DSR） has been considered as a replacement for traditional transplanted flooded rice （TFR）. However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.展开更多
Optimum seeding density is necessary to achieve the production potential of a cultivar in all crops. To investigate the performance of different cultivars in direct seeded rice in response to various seeding densities...Optimum seeding density is necessary to achieve the production potential of a cultivar in all crops. To investigate the performance of different cultivars in direct seeded rice in response to various seeding densities, a field experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad during the kharif 2012. Super basmati (fine rice) and KSK-133 (coarse rice) were sown using seeding densities of 30, 45, 60 and 75 kg·ha-1. Results indicated that leaf area index and crop growth rate varied among rice cultivars as well as various seeding densities. The growth of rice at seeding density of 75 kg·ha-1 was higher than rest of treatments. The response of rice yield and its components like number of productive tillers, number of kernels per panicle and 1000-kernal weight differed significantly under the influence of cultivars and various seeding densities. Seeding density of 75 kg·ha-1 remained superior for both rice cultivars regarding final yield. This treatment furnished kernel yields of 3.83 and 5.49 t·ha-1 in fine and coarse rice, respectively which were significantly higher than other treatments. However, Kernel quality was improved in terms of lower number of sterile and chalky kernels at lower seeding densities (30 kg·ha-1). Based on these findings, it is concluded that using seeding density of 75 kg·ha-1 for direct seeded fine and coarse rice cultivars is beneficial in terms of better growth and higher yield but kernel quality is reduced by increasing the seeding density.展开更多
Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated t...Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.展开更多
Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season...Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.展开更多
Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 pha...Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 phase paralleling to the growth direction was found in the final lamellar microstructure.Higher growth rate(>30 mm/h)led to the failure of seeding process.Based on these results,a new mechanism is proposed to describe the seeding process of the hypo-peritectic Ti Al alloys.The peritecticαphase is suggested to directly nucleate from the melt,and then act as nucleus for transformedαphase in the subsequentβtoαtransformation.At the higher growth rate,the appearance ofβphase secondary dendrites and homogeneous nucleation lead to the failure of seeding process.High Nb addition leads to a large amount of residualβphase,and theseβdendrites finally evolve into B2 phase.The room temperature tensile elongation was measured to be 11.9-18.5%for Ti-46 Al-8 Nb PST crystals,which is the highest ever reported value for Ti Al based alloys.展开更多
Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was de...Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was deve- loped. The simulation results indicate that the rate of apparent crystal growth during seeded precipitation exhibits a manifest dependence on the crystal size. In general, there is an obvious increase in the apparent crystal growth rate with the augment in crystal size. The apparent activation energy increases with the increase of characteristic crystal size, which indicates that the growth of small crystals is controlled by surface chemical reaction; it is gradually controlled by both the surface reaction and diffusion with the augment in crystal size.展开更多
Submicron-sized peanut-shaped poly（methyl methacrylate）/polystyrene （PMMA/PS） particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed p...Submicron-sized peanut-shaped poly（methyl methacrylate）/polystyrene （PMMA/PS） particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut- shaped particles showed a novel internal morphology： PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.展开更多
Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images...Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images,and is hard to guarantee security.To solve these problems,steganography using reversible texture synthesis based on seeded region growing and LSB is proposed.Secret information is embedded in the process of synthesizing texture image from the existing natural texture.Firstly,we refine the visual effect.Abnormality of synthetic texture cannot be fully prevented if no approach of controlling visual effect is applied in the process of generating synthetic texture.We use seeded region growing algorithm to ensure texture’s similar local appearance.Secondly,the size and capacity of image can be decreased by introducing the information segmentation,because the capacity of the secret information is proportional to the size of the synthetic texture.Thirdly,enhanced security is also a contribution in this research,because our method does not need to transmit parameters for secret information extraction.LSB is used to embed these parameters in the synthetic texture.展开更多
Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of...Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.展开更多
Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker...Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.展开更多
In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room t...In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room temperature, and the P（St-MAA）/P（St- NaSS） core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） using AIBN as initiator in the presence of N,N^-methylenebisacrylamide （BAA, water-soluble crosslinker）. Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%, the narrow dispersed P（St-MAA） seed particles with the diameter of 150 nm and the P（St-MAA）/P（St-NaSS） core/shell latexes with the particle size of about 200 nm were synthesized. When the 25/75 mole ratio of NaSS/（St ＋ MAA） and 2 tool% of BAA were used in the seeded emulsion polymerization, the resulted P（St-MAA）/P（St-NaSS） latex product showed a low weight loss after water extraction, and the NaSS unit content in the whole particle and in the shell reached 11.7 mol% and 34.6 mol%, resoectivelv.展开更多
The doubly thermo-responsive triblock copolymer nanoparticles of polystyrene-block-poly（N- isopropylacrylamide）-block-poly[N,N-（dimethylamino） ethyl methacrylate] （PS-b-PNIPAM-b-PDMAEMA） are successfully prepare...The doubly thermo-responsive triblock copolymer nanoparticles of polystyrene-block-poly（N- isopropylacrylamide）-block-poly[N,N-（dimethylamino） ethyl methacrylate] （PS-b-PNIPAM-b-PDMAEMA） are successfully prepared through the seeded RAFT polymerization in situ by using the PS-b-PNIPAM-TTC diblock copolymer nanoparticles as the seed. The seeded RAFT polymerization undergoes a pseudo-first-order kinetics procedure, and the molecular weight increases with the monomer conversion linearly. The hydrodynamic diameter （Dh） of the triblock copolymer nanoparticles increases with the extension of the PDMAEMA block. In addition, the double thermo-response behavior of the PS-b-PNIPAM-b-PDMAEMA nanoparticles is detected by turbidity analysis, temperature-dependent 1H-NMR analysis, and DLS analysis. The seeded RAFT polymerization is believed as a valid method to prepare triblock copolymer nanoparticles containing two thermo-responsive blocks.展开更多
A new texture feature-based seeded region growing algorithm is proposed for automated segmentation of organs in abdominal MR images. 2D Co-occurrence texture feature, Gabor texture feature, and both 2D and 3D Semi- va...A new texture feature-based seeded region growing algorithm is proposed for automated segmentation of organs in abdominal MR images. 2D Co-occurrence texture feature, Gabor texture feature, and both 2D and 3D Semi- variogram texture features are extracted from the image and a seeded region growing algorithm is run on these feature spaces. With a given Region of Interest (ROI), a seed point is automatically se-lected based on three homogeneity criteria. A threshold is then obtained by taking a lower value just before the one causing ‘explosion’. This algorithm is tested on 12 series of 3D ab-dominal MR images.展开更多
The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous...The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous feed-stocks. In this work, we show an approach to preparing seeded substrates for layer-transferrable silicon films. The commercial silicon wafers are used as mother substrates, on which periodically patterned silicon rod arrays are fabricated, and all of the surfaces of the wafers and rods are sheathed by thermal silicon oxide. Thermal evaporated aluminum film is used to fill the gaps between the rods and as the stiff mask, while polymethyl methacrylate （PMMA） and photoresist are used as the soft mask to seal the gap between the filled aluminum and the rods. Under the joint resist of the stiff and soft masks, the oxide on the rod head is selectively removed by wet etching and the seed site is formed on the rod head. The seeded substrate is obtained after the removal of the masks. This joint mask technique will promote the endeavor of the exploration of mechanically stable, unlimitedly reusable substrates for the kerfless technology.展开更多
基金support from the Science and Technology Program of Guangzhou(No.2024A04J2821)the National Natural Science Foundation of China(Nos.52222301,22171055)the Guangdong Natural Science Foundation for Distinguished Young Scholar(No.2022B1515020078)。
文摘Core-shell colloidal particles with a polymer layer have broad applications in different areas.Herein,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and photoinduced seeded reversible addition-fragmentation chain transfer(RAFT)polymerization to prepare a diverse set of core-shell colloidal particles with a well-defined polymer layer.Chemical compositions,structures,and thicknesses of polymer layers could be conveniently regulated by using different types of monomers and feed[monomer]/[chain transfer agent]ratios during seeded RAFT polymerization.
基金supported by the National Key Research and Development Program of China (Grant No.2019YFE0197100)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences。
文摘Rice direct seeding technology is an appealing alternative to traditional transplanting because it conserves labor and irrigation resources.Nevertheless,there are two main issues,salt stress and alkaline stress,which contribute to poor emergence and seedling growth,thereby preventing the widespread adoption and application of this technique in the Ningxia Region of China.Therefore,to determine whether germination can be promoted by mixed-oligosaccharide(KP)priming(in which seeds are soaked in a KP solution before sowing)under salt and alkaline stress,a proteomics study was performed.KP-priming significantly mitigated abiotic stress,such as salt and alkaline stress,by inhibiting root elongation,ultimately improving seedling establishment.By comparing the proteomics analyses,we found that energy metabolic pathway was a vital factor in KP-priming,which explains the alleviation of salt and alkaline stress.Key proteins involved in starch mobilization,pyruvate mobilization,and ATP synthesis,were up-regulated by KP-priming,significantly blocking salt and alkaline-triggered starch accumulation while enhancing pyruvate metabolism.KP-priming also up-regulated ATP synthase to improve energy efficiency,thereby improving ATP production.In addition,it enhanced antioxidant enzymatic activities and reduced the accumulation of reactive oxygen species.All of these factors contributed to a better understanding of the energy regulatory pathway enhanced by KP-priming,which mediated the promotion of growth under salt and alkaline conditions.Thus,this study demonstrated that KP-priming can improve rice seed germination under salt and alkaline stress by altering energy metabolism.
基金Project(51274242)supported by the National Natural Science Foundation of China
文摘The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al（OH）4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na＋Al（OH）4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation.
基金Project(51274242)supported by the National Natural Science Foundation of China
文摘High soda content in fine alumina trihydrate（ATH） limits its application and increases the soda consumption. The variation of soda content in the fine ATH by seeded precipitation was determined by detection of electric conductivity of solution, soda content in ATH, measurement of particle size distribution and microscopic analysis. The results show that high concentration of sodium aluminate solution, ground circulative seed, low temperature or fast initial precipitation rate increases the soda content in ATH. Soda mainly exists in lattice soda and less soda in desilication product （DSP） exists in the fine ATH precipitated from sodium aluminate solution with concentration of Al2O3 （ρAl2O3） more than 160 g/L and mass ratio of alumina to silica （μSiO2） of 400, and lattice soda decreases with increasing initial precipitation temperature, aging seed, and low precipitation rate and precipitation time. Results also imply that -＋ 4）Na Al（OH ion-pair influences lattice soda content in ATH on the basis of electric conductivity variation.
基金Supported by Natural Science Foundation of Hunan Province(12JJ6026)Innovation Platform in Higher Educational Institutions of Hunan Province(14K053)Hunan Province Higher Educational Institutions Industrialization Program(13CY030)~~
文摘The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli （L.） Beauv and other gramineous weed control efficiency with four concentrations of 20% cyhalofop-dutyl WP and 100 g/L cyhalofop-dutyl EC in direct seeded rice fields, and analyzed the yield-increasing effect and safety of rice. The results showed that 20% cyhalofop-butyl WP had a good control efficiency on grass weeds such as Leptochloa chinensis（L.） Nees, Echinoch/oa crusgalli（L.） Beauv and other grasses. The effective dosage of 90-150 g/hm2 was over 90.7% on Lep- foch/oa chinensis（L.） Nees and the comprehensive control effect of the grass weeds was above 86.7%, which was basically consistent with 100 g/L cyhalofop-dutyl EC. Furthermore, 20% cyhalofop-dutyl WP was high security for direct seeded rice fields. The yield of rice was increased by 10.18%-11.22% after spraying herbicide. There- fore, 20% of cyhalofop-dutyl WP can be used as a special herbicide for controlling Leptochloa chinensis（L.） Beauv in direct seeded rice fields, and has a good applica- tion prospect.
文摘[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effects were observed 5, 10, 15 and 30 d after drug application, with the remained weeds surveyed 15 and 30 d after drug application. [Result] The test showed pyrazosulfuron-ethyl·quinclorac 50%WP was safe to rice as treatment agent of stem and leaf, and rice yield increased dramatical y, with the growth rate in 2.1%-49.3%. After the drug application, the prevention effects on Echinochloa crusgal i, Ludwimlia prostrata, Monochoria vamli-nalis, and Zong grass were 92.2%, 96.6%, 93.5%, and 94.8%, and the effects on fresh weight were 94.8%, 97.1%, 93.3% and 94.9%, respectively. [Conclusion] Pyra-zosulfuron-ethyl·quinclorac 50% WP can be taken as treatment agents of stem and leaf of dry direct seeded rice.
基金supported by the National Natural Science Foundation of China(Grant No.31371571)the National High Technology Research and Development Program of China(863 Program)(Grant No.2014AA10A605)the Fundamental Research Funds for the Central Universities(Grant No.2662017JC001)
文摘Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice （DSR） has been considered as a replacement for traditional transplanted flooded rice （TFR）. However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.
文摘Optimum seeding density is necessary to achieve the production potential of a cultivar in all crops. To investigate the performance of different cultivars in direct seeded rice in response to various seeding densities, a field experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad during the kharif 2012. Super basmati (fine rice) and KSK-133 (coarse rice) were sown using seeding densities of 30, 45, 60 and 75 kg·ha-1. Results indicated that leaf area index and crop growth rate varied among rice cultivars as well as various seeding densities. The growth of rice at seeding density of 75 kg·ha-1 was higher than rest of treatments. The response of rice yield and its components like number of productive tillers, number of kernels per panicle and 1000-kernal weight differed significantly under the influence of cultivars and various seeding densities. Seeding density of 75 kg·ha-1 remained superior for both rice cultivars regarding final yield. This treatment furnished kernel yields of 3.83 and 5.49 t·ha-1 in fine and coarse rice, respectively which were significantly higher than other treatments. However, Kernel quality was improved in terms of lower number of sterile and chalky kernels at lower seeding densities (30 kg·ha-1). Based on these findings, it is concluded that using seeding density of 75 kg·ha-1 for direct seeded fine and coarse rice cultivars is beneficial in terms of better growth and higher yield but kernel quality is reduced by increasing the seeding density.
文摘Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.
基金supported by the National Natural Science Foundation of China(31971845 and 32101819)the earmarked fund for China Agriculture Research System(CARS-01-20)the China Postdoctoral Science Foundation(2021M691179)。
文摘Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.
基金National Natural Science Foundation of China(No.51701209)National Key Research and Development Program of China(Nos.2016YFB0701304)。
文摘Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 phase paralleling to the growth direction was found in the final lamellar microstructure.Higher growth rate(>30 mm/h)led to the failure of seeding process.Based on these results,a new mechanism is proposed to describe the seeding process of the hypo-peritectic Ti Al alloys.The peritecticαphase is suggested to directly nucleate from the melt,and then act as nucleus for transformedαphase in the subsequentβtoαtransformation.At the higher growth rate,the appearance ofβphase secondary dendrites and homogeneous nucleation lead to the failure of seeding process.High Nb addition leads to a large amount of residualβphase,and theseβdendrites finally evolve into B2 phase.The room temperature tensile elongation was measured to be 11.9-18.5%for Ti-46 Al-8 Nb PST crystals,which is the highest ever reported value for Ti Al based alloys.
文摘Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was deve- loped. The simulation results indicate that the rate of apparent crystal growth during seeded precipitation exhibits a manifest dependence on the crystal size. In general, there is an obvious increase in the apparent crystal growth rate with the augment in crystal size. The apparent activation energy increases with the increase of characteristic crystal size, which indicates that the growth of small crystals is controlled by surface chemical reaction; it is gradually controlled by both the surface reaction and diffusion with the augment in crystal size.
基金supported by National Natural Science Foundation of China(No.50943028)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Submicron-sized peanut-shaped poly（methyl methacrylate）/polystyrene （PMMA/PS） particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut- shaped particles showed a novel internal morphology： PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.
基金This work was mainly supported by National Natural Science Foundation of China(No.61370218)Public Welfare Technology and Industry Project of Zhejiang Provincial Science Technology Department(No.2016C31081,No.LGG18F020013)。
文摘Steganography technology has been widely used in data transmission with secret information.However,the existing steganography has the disadvantages of low hidden information capacity,poor visual effect of cover images,and is hard to guarantee security.To solve these problems,steganography using reversible texture synthesis based on seeded region growing and LSB is proposed.Secret information is embedded in the process of synthesizing texture image from the existing natural texture.Firstly,we refine the visual effect.Abnormality of synthetic texture cannot be fully prevented if no approach of controlling visual effect is applied in the process of generating synthetic texture.We use seeded region growing algorithm to ensure texture’s similar local appearance.Secondly,the size and capacity of image can be decreased by introducing the information segmentation,because the capacity of the secret information is proportional to the size of the synthetic texture.Thirdly,enhanced security is also a contribution in this research,because our method does not need to transmit parameters for secret information extraction.LSB is used to embed these parameters in the synthetic texture.
基金Project(20476107) supported by the National Natural Science Foundation of ChinaProject(2005CB623702) supported by the National Basic Research Program of China
文摘Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.
基金partially supported by the National Natural Science Foundation of China(No.50943028)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.
文摘In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room temperature, and the P（St-MAA）/P（St- NaSS） core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） using AIBN as initiator in the presence of N,N^-methylenebisacrylamide （BAA, water-soluble crosslinker）. Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%, the narrow dispersed P（St-MAA） seed particles with the diameter of 150 nm and the P（St-MAA）/P（St-NaSS） core/shell latexes with the particle size of about 200 nm were synthesized. When the 25/75 mole ratio of NaSS/（St ＋ MAA） and 2 tool% of BAA were used in the seeded emulsion polymerization, the resulted P（St-MAA）/P（St-NaSS） latex product showed a low weight loss after water extraction, and the NaSS unit content in the whole particle and in the shell reached 11.7 mol% and 34.6 mol%, resoectivelv.
基金financially supported by 973 Program of China,under the contract(No.2015CB655105)the National Science Fund for Distinguished Young Scholars(No.51225801)+1 种基金the National Natural Science Foundation of China(No.51408275)the Provincial Science and Technology Cooperation Project of Jiangsu-Guangxi cooperation project(No.BM2014050)
文摘The doubly thermo-responsive triblock copolymer nanoparticles of polystyrene-block-poly（N- isopropylacrylamide）-block-poly[N,N-（dimethylamino） ethyl methacrylate] （PS-b-PNIPAM-b-PDMAEMA） are successfully prepared through the seeded RAFT polymerization in situ by using the PS-b-PNIPAM-TTC diblock copolymer nanoparticles as the seed. The seeded RAFT polymerization undergoes a pseudo-first-order kinetics procedure, and the molecular weight increases with the monomer conversion linearly. The hydrodynamic diameter （Dh） of the triblock copolymer nanoparticles increases with the extension of the PDMAEMA block. In addition, the double thermo-response behavior of the PS-b-PNIPAM-b-PDMAEMA nanoparticles is detected by turbidity analysis, temperature-dependent 1H-NMR analysis, and DLS analysis. The seeded RAFT polymerization is believed as a valid method to prepare triblock copolymer nanoparticles containing two thermo-responsive blocks.
文摘A new texture feature-based seeded region growing algorithm is proposed for automated segmentation of organs in abdominal MR images. 2D Co-occurrence texture feature, Gabor texture feature, and both 2D and 3D Semi- variogram texture features are extracted from the image and a seeded region growing algorithm is run on these feature spaces. With a given Region of Interest (ROI), a seed point is automatically se-lected based on three homogeneity criteria. A threshold is then obtained by taking a lower value just before the one causing ‘explosion’. This algorithm is tested on 12 series of 3D ab-dominal MR images.
基金Project supported by the National Natural Science Foundation of China(Grant No.11374313)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11504392)
文摘The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous feed-stocks. In this work, we show an approach to preparing seeded substrates for layer-transferrable silicon films. The commercial silicon wafers are used as mother substrates, on which periodically patterned silicon rod arrays are fabricated, and all of the surfaces of the wafers and rods are sheathed by thermal silicon oxide. Thermal evaporated aluminum film is used to fill the gaps between the rods and as the stiff mask, while polymethyl methacrylate （PMMA） and photoresist are used as the soft mask to seal the gap between the filled aluminum and the rods. Under the joint resist of the stiff and soft masks, the oxide on the rod head is selectively removed by wet etching and the seed site is formed on the rod head. The seeded substrate is obtained after the removal of the masks. This joint mask technique will promote the endeavor of the exploration of mechanically stable, unlimitedly reusable substrates for the kerfless technology.
