Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and frag...Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.展开更多
[Objectives]This study was conducted to investigate the scientific application of silicon fertilizer in rice cultivation,one of the staple crops.[Methods]In 2022,Yandu District carried out a special experiment and fie...[Objectives]This study was conducted to investigate the scientific application of silicon fertilizer in rice cultivation,one of the staple crops.[Methods]In 2022,Yandu District carried out a special experiment and field demonstration study on the effects of foliar application of Zhengda water-soluble silicon fertilizer on rice production.[Results]The preliminary results showed that①Zhengda water-soluble silicon fertilizer could effectively improve the growth and development of rice and improve the population quality.The peak number of tillers,productive tiller percentage,number of effective panicles and number of effective grains per panicle increased by 6.7%,5.8%,5.5%,and 1.2%,respectively.②The yield and processing quality were improved.After applying silicon fertilizer,the yield per unit area increased by about 6.8%,and the unpolished rice yield,milled rice yield and head rice yield increased by 0.7%,1.94%and 2.15%respectively.[Conclusions]The demonstration application of silicon fertilizer in field cultivation of rice in Yandu District further proves previous research conclusions and has important practical significance.展开更多
Based on the skills of initializing weight distribution, adding an impulse in a neural network and expanding the ideal of plural weights, an artificial neural network model with three connection weights between one an...Based on the skills of initializing weight distribution, adding an impulse in a neural network and expanding the ideal of plural weights, an artificial neural network model with three connection weights between one and another neural unit was established to predict silicon content of blast furnace hot metal. After the neural network was trained in the off-line state on the basis of a large number of practical data of a commercial blast furnace and making many learning patterns, satisfactory testing and simulating results of the model were obtained.展开更多
Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in indu...Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in industrial reheating furnaces for the production of hot-rolled strips. Our results show that when the heating temperature was greater than the melting point of Fe_2SiO_4, the oxidation rates of steels with different silicon contents were the same; the total mass gain decreased with increasing silicon content, whereas it increased with increasing oxygen content. The oxidation rates for steels with different silicon contents were constant with respect to time under isothermal conditions. In addition, the starting oxidation temperature, the intense oxidation temperature, and the finishing oxidation temperature increased with increasing silicon content; the intense oxidation temperature had no correlation with the melting of Fe_2SiO_4. Moreover, the silicon distributed in two forms: as Fe_2SiO_4 at the interface between the innermost layer of oxide scale and the iron matrix, and as particles containing silicon in grains and grain boundaries in the iron matrix.展开更多
The effects of phenyl content and group distribution on the refractive index of phenyl silicone oil were investigated by synthesis and characterization of silicone oils of different molecular structures.A group contri...The effects of phenyl content and group distribution on the refractive index of phenyl silicone oil were investigated by synthesis and characterization of silicone oils of different molecular structures.A group contribution function model was established to predict the refractive index. The results showed that refractive index of phenyl silicone oil increased as its phenyl content increased. A linear equation had been established to describe the quantitative relationship between the refractive index and phenyl content.Refractive index values from the group contribution function model showed good consistency with experimental results.展开更多
A method for rapid determination of silicon content in rice was introduced. The reliability of this method was verified byusing a recombinant inbred line (RIL) population of rice cross Zhenshan 97B / Milyang 46. Two h...A method for rapid determination of silicon content in rice was introduced. The reliability of this method was verified byusing a recombinant inbred line (RIL) population of rice cross Zhenshan 97B / Milyang 46. Two hundred and forty-nine RILs weretransplanted in two replications. Simple correlation coefficients on the silicon content in the hull, flag leaf and stem in rice betweenduplicate samples of 498 rice materials were 0.97954, 0.97026 and 0.98848, respectively. Ten representative samples wereselected for measurement using the high-temperature alkaline fusion method. Simple correlation coefficient between the siliconcontents determined by the high-temperature alkaline fusion method and by the present method is 0.9993.展开更多
A pulsed Nd:YAG (yttrium aluminum garnet) laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, pha...A pulsed Nd:YAG (yttrium aluminum garnet) laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution, within the obtained cladding coatings, were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), with associated energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The microhardness was also measured along the depth direction of the specimens. A crack-and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized sin-gle-track and multi-track laser cladding. The phases of the coating are α-Fe, γ-Fe, and FeSi. The high microhardness of the la-ser-cladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt/ in the single-track cladding and 6.5wt/ in the multi-track cladding, respectively.展开更多
The time series data of silicon content in hot metal were identified to have the chaotic feature because of the positive maximum Lyapunov exponent, and then the time scales to predict future were estimated. Finally a ...The time series data of silicon content in hot metal were identified to have the chaotic feature because of the positive maximum Lyapunov exponent, and then the time scales to predict future were estimated. Finally a chaotic local-region model was constructed to predict silicon content in hot metal with good performance due to high hitting rate.展开更多
Some key operation variables influencing hot metal silicon content were selected, and time lag of each of them was obtained. A standardized fuzzy system model was developed to approach the random nonlinear dynamic sys...Some key operation variables influencing hot metal silicon content were selected, and time lag of each of them was obtained. A standardized fuzzy system model was developed to approach the random nonlinear dynamic system of the change of silicon content, forecast the change of silicon content and calculate silicon content. The prediction of hot metal silicon content is very successful with the data collected online from BF No.1 at Laiwu Iron and Steel Group Co.展开更多
A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diam...A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diameter of silicone oil emulsion was discussed.The experimental results showed that the emulsification method,including the quantity of the emulsifier,the time and temperature of emulsification,the emulsifying water dosage,and the stirring speed,had significant impact on the droplet size.The optimal conditions were identified to achieve a smallest droplet diameter of the emulsion at an emulsifier dosage of 6%,an emulsification temperature of 70 ℃,an emulsification time of 30 min,and a stirring speed of 1100 r/min,with water added in two portions at a ratio of 1:1.The high-solid content silicone oil emulsion with a mean droplet diameter of 2.731 μm was prepared under these conditions that could ensure absence of stratification and floating oil under centrifuging at a speed of 3000 r/min for 30 min.展开更多
A genetic algorithm based on the nested intervals chaos search (NICGA) has been given. Because the nested intervalschaos search is introduced into the NICGA to initialize the population and to lead the evolution of th...A genetic algorithm based on the nested intervals chaos search (NICGA) has been given. Because the nested intervalschaos search is introduced into the NICGA to initialize the population and to lead the evolution of the population, the NICGA has theadvantages of decreasing the population size, enhancing the local search ability, and improving the computational efficiency and op-timization precision. In a multi-layer feed forward neural network model for predicting the silicon content in hot metal, the NICGAwas used to optimize the connection weights and threshold values of the neural network to improve the prediction precision. The ap-plication results show that the precision of predicting the silicon content has been increased.展开更多
Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 （high surface area, narrow pore size dis...Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 （high surface area, narrow pore size distribution and good order）, but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal （amorphous）.展开更多
By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus add...By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus additions. The effect of phosphorus addition on hydrogen content in the melt was also studied. It was observed that the phosphorus addition made hydrogen content in alloy melts present a “see-saw" tendency.In addition to primary silicon refinement,the phosphorus promoted gas porosity formed not only in slowly cooled sections, but also in rapidly cooled sections. There was a small difference in density of full dense sample between P-refined and unrefined castings, with a larger density associated with phosphorous addition. The change of the surface tension seemed more reasonable to explain the mechanism of porosity behavior.展开更多
Ten studied steels including different carbon content, silicon content, and manganese content were deformed in compression over a temperature range of 600 ?C to 1 000 ?C at the strain rate of 1 s-1. The curves of the ...Ten studied steels including different carbon content, silicon content, and manganese content were deformed in compression over a temperature range of 600 ?C to 1 000 ?C at the strain rate of 1 s-1. The curves of the mean flow stressdeformation temperature were drawn up. The mean flow stresses of higher carbon content steels decreased continuously as the applied deformation temperature increased in the whole temperature range, while the mean flow stress of lowest carbon steel displayed an abrupt drop near the two phases region. The reason for the abrupt drop phenomena was explained as the result of phase transformation. The mean flow stresses of steels with high silicon content and low manganese content also have this phenomena.展开更多
The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6.By using an F2:3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background...The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6.By using an F2:3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background,two QTLs for hull silicon content were detected,of which qHUS6-1 was located in the distal region and qHUS6-2 in the region proximal to the centromere.Three rice plants carrying small heterozygous segments in the target region were selected,of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region.Three F2:3 populations were derived from the selfed seeds of the three plants,respectively.QTL mapping was performed using the two populations segregating in the qHUS6-1 region,and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417.Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2:3 population.Two QTLs were separated with two-way ANOVA,of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.展开更多
The properties of cast iron grade GL 250 are dependent on the microstructures developed during casting. These microstructures are in turn dependent on the composition of the alloy, type of mould and other numerous cas...The properties of cast iron grade GL 250 are dependent on the microstructures developed during casting. These microstructures are in turn dependent on the composition of the alloy, type of mould and other numerous casting practice variables such as shake-out time, pouring temperature, mould ambient conditions and inoculating technique. In this work, the effect of silicon content and shake-out time on the grain size (GS) and hardness properties of GL 250 cast iron was studied using a pouring temperature of 1400℃ and sand mould casting. Using charge materials consisting of pig iron and other additives, GL 250 castings containing silicon contents of 1.7, 2.1 and 2.7% were casted using a constant pouring temperature of 1400℃, molding sand of specified properties and ambient mould temperature of 32℃. Results showed that type A flake type was obtained at 30mins shakeout time for all samples for the C.I composition under study. Increasing shake-out time decreased hardness and increased carbide grain size. Increasing silicon content was observed to increase grain size and reduce free graphite but with resultant decrease in hardness. Two mathematical relationships were derived. One related grain-size to silicon content and shakeout time while the second related Brinnel Hardness to Silicon content and shake-out time. They are: Grain Size=0.40 Si+0.17Shake-out Time-0.15 and BHN=-60.53Si-7.15Shake-out Time+329.35 at 1400℃ pouring temperature in a molding sand of specified properties and sand mould ambient temperature of 32℃.展开更多
The inductively coupled plasma chemical vapor deposition(ICP-CVD) deposited silicon nitride(SiN_(x)) thin film was evaluated for its application as the electrical insulating film for a capacitor device.In order to ach...The inductively coupled plasma chemical vapor deposition(ICP-CVD) deposited silicon nitride(SiN_(x)) thin film was evaluated for its application as the electrical insulating film for a capacitor device.In order to achieve highest possible dielectric strength of SiN_(x),the process parameters of ICP-CVD were carefully tuned to control hydrogen in SiN_(x) films by means of tuning N_(2)/SiH_(4) ratio and radio frequency(RF) power.Besides electrical measurements,the hydrogen content in the films was measured by dynamic secondary ion mass spectrometry(D-SIMS).Fourier transform infrared spectroscopy(FTIR) and micro Raman spectroscopy were used to characterize the SiN_(x) films by measuring Si-H and N-H bonds’ intensities.It was found that the more Si-H bonds lead to the higher dielectric strength.展开更多
There are some problems in steelmaking with hot metal containing low silicon content such as difficulty in slag formation, less slag for dephosphorization and slag adhesion on oxygen lance and hood. To overcome these ...There are some problems in steelmaking with hot metal containing low silicon content such as difficulty in slag formation, less slag for dephosphorization and slag adhesion on oxygen lance and hood. To overcome these problems, experiments were conducted and some improvements were obtained, such as adding appropriate flux, increasing the lance position slightly during steelmaking and using effective multi-outlet nozzle. Moreover, to keep normal heating rate, the ore and scrap charge should be reduced due to less chemical heat input in steelmaking.展开更多
By combining a silicon-based lithium niobate modulator and a silicon-based Si3N4resonator with silicon-based photonics technology,a highly systematic design of a hybrid integrated optical gyroscope with enhanced recip...By combining a silicon-based lithium niobate modulator and a silicon-based Si3N4resonator with silicon-based photonics technology,a highly systematic design of a hybrid integrated optical gyroscope with enhanced reciprocity sensitivity and a dual micro-ring structure is proposed for the first time in this paper.The relationship between the device's structural parameters and optical performance is also analyzed by constructing a complete simulation link,which provides a theoretical design reference to improve the system's sensitivity.When the wavelength is 1550 nm,the conversion frequency of the dual-ring optical path is 50 MHz,the coupling coefficient is 0.2,and the radius R is 1000μm,the quality factor of the silicon-based Si_(3)N_(4)resonator is 2.58×10^(5),which is 1.58 times that of the silicon-on-insulator resonator.Moreover,the effective number of times the light travels around the ring before leaving the micro-ring is 5.93,which is 1.62 times that of the silicon-on-insulator resonator.The work fits the gyro dynamic output diagram,and solves the problem of low sensitivity at low speed by setting the phase offset.This results provide a basis for the further optimization of design and chip processing of the integrated optical gyroscope.展开更多
The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new meth...The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new method to estimate the UWC of saturated sandstones at low temperature by using the ultrasonic velocity.Ultrasonic velocity variations can be divided into the normal temperature stage(20 to 0℃),quick phase transition stage(0 to-5℃)and slow phase transition stage(-5 to-25℃).Most increment of ultrasonic velocity is completed in the quick phase transition stage and then turns to be almost a constant in the slow phase transition stage.In addition,the UWC is also measured by using nuclear magnetic resonance(NMR)technology.It is validated that the ultrasonic velocity and UWC have a similar change law against freezing and thawing temperatures.The WE(weighted equation)model is appropriate to estimate the UWC of saturated sandstones,in which the parameters have been accurately determined rather than by data fitting.In addition,a linear relationship between UWC and ultrasonic velocity is built based on pore ice crystallization theory.It is evidenced that this linear function can be adopted to estimate the UWC at any freezing temperature by using P-wave velocity,which is simple,practical,and accurate enough compared with the WE model.展开更多
基金This project was financially supported by the National Natural Science Foundation of China(31601244 and 31971843)the Guangdong Provincial Key Field Research and Development Plan Project,China(2019B020221003)the Modern Agricultural Industrial Technology System of Guangdong Province,China(2020KJ105).
文摘Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.
文摘[Objectives]This study was conducted to investigate the scientific application of silicon fertilizer in rice cultivation,one of the staple crops.[Methods]In 2022,Yandu District carried out a special experiment and field demonstration study on the effects of foliar application of Zhengda water-soluble silicon fertilizer on rice production.[Results]The preliminary results showed that①Zhengda water-soluble silicon fertilizer could effectively improve the growth and development of rice and improve the population quality.The peak number of tillers,productive tiller percentage,number of effective panicles and number of effective grains per panicle increased by 6.7%,5.8%,5.5%,and 1.2%,respectively.②The yield and processing quality were improved.After applying silicon fertilizer,the yield per unit area increased by about 6.8%,and the unpolished rice yield,milled rice yield and head rice yield increased by 0.7%,1.94%and 2.15%respectively.[Conclusions]The demonstration application of silicon fertilizer in field cultivation of rice in Yandu District further proves previous research conclusions and has important practical significance.
文摘Based on the skills of initializing weight distribution, adding an impulse in a neural network and expanding the ideal of plural weights, an artificial neural network model with three connection weights between one and another neural unit was established to predict silicon content of blast furnace hot metal. After the neural network was trained in the off-line state on the basis of a large number of practical data of a commercial blast furnace and making many learning patterns, satisfactory testing and simulating results of the model were obtained.
基金the financial support from the National Natural Science Foundation of China(NSFC)(No.51274154)the State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel Group)
文摘Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in industrial reheating furnaces for the production of hot-rolled strips. Our results show that when the heating temperature was greater than the melting point of Fe_2SiO_4, the oxidation rates of steels with different silicon contents were the same; the total mass gain decreased with increasing silicon content, whereas it increased with increasing oxygen content. The oxidation rates for steels with different silicon contents were constant with respect to time under isothermal conditions. In addition, the starting oxidation temperature, the intense oxidation temperature, and the finishing oxidation temperature increased with increasing silicon content; the intense oxidation temperature had no correlation with the melting of Fe_2SiO_4. Moreover, the silicon distributed in two forms: as Fe_2SiO_4 at the interface between the innermost layer of oxide scale and the iron matrix, and as particles containing silicon in grains and grain boundaries in the iron matrix.
基金National Natural Science Foundation of China(No.11304048)Special Fund Project for Technology Development of Guangdong Province,China(No.2016B070701023)Funds of Applied Science and Technology Research in Guangdong Province,China(Nos.2017A070701024,2017A070702020)
文摘The effects of phenyl content and group distribution on the refractive index of phenyl silicone oil were investigated by synthesis and characterization of silicone oils of different molecular structures.A group contribution function model was established to predict the refractive index. The results showed that refractive index of phenyl silicone oil increased as its phenyl content increased. A linear equation had been established to describe the quantitative relationship between the refractive index and phenyl content.Refractive index values from the group contribution function model showed good consistency with experimental results.
文摘A method for rapid determination of silicon content in rice was introduced. The reliability of this method was verified byusing a recombinant inbred line (RIL) population of rice cross Zhenshan 97B / Milyang 46. Two hundred and forty-nine RILs weretransplanted in two replications. Simple correlation coefficients on the silicon content in the hull, flag leaf and stem in rice betweenduplicate samples of 498 rice materials were 0.97954, 0.97026 and 0.98848, respectively. Ten representative samples wereselected for measurement using the high-temperature alkaline fusion method. Simple correlation coefficient between the siliconcontents determined by the high-temperature alkaline fusion method and by the present method is 0.9993.
基金the National Natural Science Foundation of China (No.50474084).
文摘A pulsed Nd:YAG (yttrium aluminum garnet) laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution, within the obtained cladding coatings, were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), with associated energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The microhardness was also measured along the depth direction of the specimens. A crack-and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized sin-gle-track and multi-track laser cladding. The phases of the coating are α-Fe, γ-Fe, and FeSi. The high microhardness of the la-ser-cladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt/ in the single-track cladding and 6.5wt/ in the multi-track cladding, respectively.
文摘The time series data of silicon content in hot metal were identified to have the chaotic feature because of the positive maximum Lyapunov exponent, and then the time scales to predict future were estimated. Finally a chaotic local-region model was constructed to predict silicon content in hot metal with good performance due to high hitting rate.
文摘Some key operation variables influencing hot metal silicon content were selected, and time lag of each of them was obtained. A standardized fuzzy system model was developed to approach the random nonlinear dynamic system of the change of silicon content, forecast the change of silicon content and calculate silicon content. The prediction of hot metal silicon content is very successful with the data collected online from BF No.1 at Laiwu Iron and Steel Group Co.
文摘A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diameter of silicone oil emulsion was discussed.The experimental results showed that the emulsification method,including the quantity of the emulsifier,the time and temperature of emulsification,the emulsifying water dosage,and the stirring speed,had significant impact on the droplet size.The optimal conditions were identified to achieve a smallest droplet diameter of the emulsion at an emulsifier dosage of 6%,an emulsification temperature of 70 ℃,an emulsification time of 30 min,and a stirring speed of 1100 r/min,with water added in two portions at a ratio of 1:1.The high-solid content silicone oil emulsion with a mean droplet diameter of 2.731 μm was prepared under these conditions that could ensure absence of stratification and floating oil under centrifuging at a speed of 3000 r/min for 30 min.
文摘A genetic algorithm based on the nested intervals chaos search (NICGA) has been given. Because the nested intervalschaos search is introduced into the NICGA to initialize the population and to lead the evolution of the population, the NICGA has theadvantages of decreasing the population size, enhancing the local search ability, and improving the computational efficiency and op-timization precision. In a multi-layer feed forward neural network model for predicting the silicon content in hot metal, the NICGAwas used to optimize the connection weights and threshold values of the neural network to improve the prediction precision. The ap-plication results show that the precision of predicting the silicon content has been increased.
文摘Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 （high surface area, narrow pore size distribution and good order）, but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal （amorphous）.
文摘By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus additions. The effect of phosphorus addition on hydrogen content in the melt was also studied. It was observed that the phosphorus addition made hydrogen content in alloy melts present a “see-saw" tendency.In addition to primary silicon refinement,the phosphorus promoted gas porosity formed not only in slowly cooled sections, but also in rapidly cooled sections. There was a small difference in density of full dense sample between P-refined and unrefined castings, with a larger density associated with phosphorous addition. The change of the surface tension seemed more reasonable to explain the mechanism of porosity behavior.
基金Funded by Shanghai Pujiang Program(No.16PJ1430200)
文摘Ten studied steels including different carbon content, silicon content, and manganese content were deformed in compression over a temperature range of 600 ?C to 1 000 ?C at the strain rate of 1 s-1. The curves of the mean flow stressdeformation temperature were drawn up. The mean flow stresses of higher carbon content steels decreased continuously as the applied deformation temperature increased in the whole temperature range, while the mean flow stress of lowest carbon steel displayed an abrupt drop near the two phases region. The reason for the abrupt drop phenomena was explained as the result of phase transformation. The mean flow stresses of steels with high silicon content and low manganese content also have this phenomena.
基金supported by the National Natural Science Foundation of China(GrantNo.30571062)National Hi-Tech Research and Development Program of China(Grant No.2006AA10Z1E8)the Program of Super Rice from Chinese Agricultural Ministry(Grant No.200906)
文摘The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6.By using an F2:3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background,two QTLs for hull silicon content were detected,of which qHUS6-1 was located in the distal region and qHUS6-2 in the region proximal to the centromere.Three rice plants carrying small heterozygous segments in the target region were selected,of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region.Three F2:3 populations were derived from the selfed seeds of the three plants,respectively.QTL mapping was performed using the two populations segregating in the qHUS6-1 region,and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417.Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2:3 population.Two QTLs were separated with two-way ANOVA,of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.
文摘The properties of cast iron grade GL 250 are dependent on the microstructures developed during casting. These microstructures are in turn dependent on the composition of the alloy, type of mould and other numerous casting practice variables such as shake-out time, pouring temperature, mould ambient conditions and inoculating technique. In this work, the effect of silicon content and shake-out time on the grain size (GS) and hardness properties of GL 250 cast iron was studied using a pouring temperature of 1400℃ and sand mould casting. Using charge materials consisting of pig iron and other additives, GL 250 castings containing silicon contents of 1.7, 2.1 and 2.7% were casted using a constant pouring temperature of 1400℃, molding sand of specified properties and ambient mould temperature of 32℃. Results showed that type A flake type was obtained at 30mins shakeout time for all samples for the C.I composition under study. Increasing shake-out time decreased hardness and increased carbide grain size. Increasing silicon content was observed to increase grain size and reduce free graphite but with resultant decrease in hardness. Two mathematical relationships were derived. One related grain-size to silicon content and shakeout time while the second related Brinnel Hardness to Silicon content and shake-out time. They are: Grain Size=0.40 Si+0.17Shake-out Time-0.15 and BHN=-60.53Si-7.15Shake-out Time+329.35 at 1400℃ pouring temperature in a molding sand of specified properties and sand mould ambient temperature of 32℃.
基金Project supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Grant Nos.19KJD140002 and 19KJB140008)the Key Projects of Ministry of Science and Technology of China(Grant No.SQ2020YFF0407077)+3 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant Nos.2020XKT786 and KYCX202337)the National Foreign Experts Bureau High-end Foreign Experts Project,China(Grant No.G20190114003)the Key Research and Development Program of Jiangsu Province,China(Grant No.BE2018063)the Scientific Research Program for Doctoral Teachers of JSNU(Grant No.9212218113)。
文摘The inductively coupled plasma chemical vapor deposition(ICP-CVD) deposited silicon nitride(SiN_(x)) thin film was evaluated for its application as the electrical insulating film for a capacitor device.In order to achieve highest possible dielectric strength of SiN_(x),the process parameters of ICP-CVD were carefully tuned to control hydrogen in SiN_(x) films by means of tuning N_(2)/SiH_(4) ratio and radio frequency(RF) power.Besides electrical measurements,the hydrogen content in the films was measured by dynamic secondary ion mass spectrometry(D-SIMS).Fourier transform infrared spectroscopy(FTIR) and micro Raman spectroscopy were used to characterize the SiN_(x) films by measuring Si-H and N-H bonds’ intensities.It was found that the more Si-H bonds lead to the higher dielectric strength.
文摘There are some problems in steelmaking with hot metal containing low silicon content such as difficulty in slag formation, less slag for dephosphorization and slag adhesion on oxygen lance and hood. To overcome these problems, experiments were conducted and some improvements were obtained, such as adding appropriate flux, increasing the lance position slightly during steelmaking and using effective multi-outlet nozzle. Moreover, to keep normal heating rate, the ore and scrap charge should be reduced due to less chemical heat input in steelmaking.
基金Project supported by the science and technology general project of Beijing Municipal Education Commission(Grant No.KM202111232019)Beijing Municipal Natural Science Foundation(Grant No.2214058)+4 种基金the Discipline Innovation Program of Higher Education(Grant No.D17021)the Open Project of the State Key Laboratory of Integrated Optoelectronics(Grant No.IOSKL2020KF22)Beijing Great Wall Scholars Program(Grant No.CIT&TCD20190323)the National Natural Science Foundation of China(Grant No.61875237)Beijing Youth Talent Support Program(Grant No.Z2019042)。
文摘By combining a silicon-based lithium niobate modulator and a silicon-based Si3N4resonator with silicon-based photonics technology,a highly systematic design of a hybrid integrated optical gyroscope with enhanced reciprocity sensitivity and a dual micro-ring structure is proposed for the first time in this paper.The relationship between the device's structural parameters and optical performance is also analyzed by constructing a complete simulation link,which provides a theoretical design reference to improve the system's sensitivity.When the wavelength is 1550 nm,the conversion frequency of the dual-ring optical path is 50 MHz,the coupling coefficient is 0.2,and the radius R is 1000μm,the quality factor of the silicon-based Si_(3)N_(4)resonator is 2.58×10^(5),which is 1.58 times that of the silicon-on-insulator resonator.Moreover,the effective number of times the light travels around the ring before leaving the micro-ring is 5.93,which is 1.62 times that of the silicon-on-insulator resonator.The work fits the gyro dynamic output diagram,and solves the problem of low sensitivity at low speed by setting the phase offset.This results provide a basis for the further optimization of design and chip processing of the integrated optical gyroscope.
基金National Natural Science Foundation of China(Nos.42072300 and 41702291)the Project of Natural Science Foundation of Hubei Province(No.2021CFA094).
文摘The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new method to estimate the UWC of saturated sandstones at low temperature by using the ultrasonic velocity.Ultrasonic velocity variations can be divided into the normal temperature stage(20 to 0℃),quick phase transition stage(0 to-5℃)and slow phase transition stage(-5 to-25℃).Most increment of ultrasonic velocity is completed in the quick phase transition stage and then turns to be almost a constant in the slow phase transition stage.In addition,the UWC is also measured by using nuclear magnetic resonance(NMR)technology.It is validated that the ultrasonic velocity and UWC have a similar change law against freezing and thawing temperatures.The WE(weighted equation)model is appropriate to estimate the UWC of saturated sandstones,in which the parameters have been accurately determined rather than by data fitting.In addition,a linear relationship between UWC and ultrasonic velocity is built based on pore ice crystallization theory.It is evidenced that this linear function can be adopted to estimate the UWC at any freezing temperature by using P-wave velocity,which is simple,practical,and accurate enough compared with the WE model.
