[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a sup...[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a super-high yielded region of summer maize, field experiment was conducted to research effects of N fertilizer postponing on key enzymes of N metabolism, yield of maize and N fertilizer use. [Result] After application of N fertilizer was postponed, NR, SPS and GS activities of ear-leaf of summer maize increased by 11.99%-34.87%, 8.25%-10.64% and 10.00%- 16.81% on the 28^th d of silking; content of soluble sugar in leaves enhanced signifi- cantly and accumulated nitrogen increased by 5.00%-9.74% in mature stage. The postponing fertilization of "30% of fertilizer in seedling stage+30% of fertilizer in flare- opening stage+40% of fertilizer in silking stage meets N demands of summer maize in late growth period. Compared with conventional fertilization, the maize yield, agro- nomic efficiency and use of N fertilizer all improved by 5.05%, 1.75 kg/kg and 6.87%, respectively, after application postponed. [Conclusion] Application postponing of N fertilizer maintains activity of NR, GS and SPS higher and coordinates metabolism of C and N in late growth period, to further improve yield of maize.展开更多
The mechanism of high yield of winter wheat in the field at late growth period was investigated by measuring the photosynthetic characteristics of photosystem Ⅱ (PSⅡ) and xanthophylls cycle, which could provide ph...The mechanism of high yield of winter wheat in the field at late growth period was investigated by measuring the photosynthetic characteristics of photosystem Ⅱ (PSⅡ) and xanthophylls cycle, which could provide physiological reference for breeding. Weimai 8 (W8), a super high yield cultivar, and Lumai 14 (L14), a control cultivar were object. The photosynthetic rate (Pn), parameters of chlorophyll fluorescence and chlorophyll content were measured. The Pn, maximum photochemical efficiency of PSII (Fv/Fm), quantum yield of PSII electron transport (ΦPSⅡ), efficiency of excitation energy capture by open PSII reaction centers (Fv'/Fm'), and photochemical quenching coefficient (qP) were higher in Weimai 8 compared to that in Lumai 14, a commercial high yield cultivar. Furthermore, Weirnai 8 showed a lower non- photochemical quenching coefficient and a lower de-epoxidized ratio of the xanthophyll cycle pigments than of Lumai 14 at late growth period. At mature stage, chlorophyll content of different leaves decreased both in Weimai 8 and Lumai 14. Chlorophyll content in flag, second and third leaf from the top of plant decreased more in Lumai 14 than in Weimai 8. These results suggested that Weimai 8 had more antenna pigments to absorb light energy, and had higher photosynthetic capability and photochemical efficiency of PSⅡ. The yield of Weimai 8 was also higher than that of Lumai 14.展开更多
As a structural material with low density and high strength, super-highstrength aluminum alloys have a future for wide application. However, its poor stress corrosionresistance (SCC) restricts further development. In ...As a structural material with low density and high strength, super-highstrength aluminum alloys have a future for wide application. However, its poor stress corrosionresistance (SCC) restricts further development. In present, retrogression and re-ageing (RRA)treatment, which can improve both strength and SCCR of 7XXX series alloy, is a best method to solvethis problem. The effect of RRA treatment on the microstructure evolution of a new type lowfrequency electric-magnetic casting Al-9.OZn-2.45Mg-2.2Cu-0.15Zr alloy was investigated using DSCand TEM technologies. The results show that the typical microstructure of the alloy at T6 conditionis characterized by both fine eta' and GP zone homogeneously distributed in the matrix andcontinuous r) particles occurred on the grain-boundary. After RRA treatment, the matrixprecipitations are mainly fine and dispersed eta' and eta phases, being coarser and more stable thanthat from T6 temper. While, the grain-boundary microstructure is very close to that resulting fromT73 temper. High retrogression temperature and long retrogression time leads to a more stablemicrostructure after re-ageing.展开更多
Super-high sulfur coal resultes in serious coal-derived pollution but might have a particular genesis. Thus,a columnar section of an Early Permian Liangshan Formation coal seam. weight average sulfur content 5.80%,fro...Super-high sulfur coal resultes in serious coal-derived pollution but might have a particular genesis. Thus,a columnar section of an Early Permian Liangshan Formation coal seam. weight average sulfur content 5.80%,from Kaili,eastern Guizhou,was studied using the methods of coal petrology and geochemistry. The results show that the seam was apparently formed in seawater-effected peat bogs that developed in two distinct stages. During the first stage various layers were formed in a supratidal bog and have a composition characteristic of a bog with a gradually decreasing sea-water effect,decreasing water dynamics,and an increasingly reductive environment. Layers in the upper seam formed during a second stage in an intertidal bog. These layers are very high in total and inorganic sulfur,the ratios of or-ganic/inorganic sulfur and V/I drop,they are high in coal ash yield and have a high ash component index,considerable barkinite,oxidized and detrital macerals,have a porphyroclatic micro-structure and are rich in pyrite,all of which indi-cate the coal-forming environment had higher oxidation potential,strong and roiling water dynamics,and intermittent exposure to a sulfur rich environment.展开更多
Some super high arch dams ( SHADs), like Xiluodu Arch Dam, after their heights reaching the magnitude of 300 m, confront lots of technical challenges in design and construction. Several crucial technologies of 6 SHA...Some super high arch dams ( SHADs), like Xiluodu Arch Dam, after their heights reaching the magnitude of 300 m, confront lots of technical challenges in design and construction. Several crucial technologies of 6 SHADs will be reviewed and discussed in this and consecutive papers, including Xiluodu, Jinping I in China, Baktiary in Iran, ete. , on the topics of the research method, criterion for evaluation and engineering application of dam safety analysis and evaluation, reasonable dam base interface, dam shape optimization, comprehensive treatments of complex foundation, anti-seismic engineering, dam construction material, concrete placement and temperature control, instrumentation and monitoring of dam operation, etc. This paper will mainly focus on the overall safety of SHADs, reasonable dam base interface analysis and evaluation and their engineering application.展开更多
This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive ...This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.展开更多
In this paper, the feasibility study of chemical flooding is carried out for ultra-high porosity and high permeability heavy oil field with permeability higher than 10 μm<sup>2</sup> and porosity greater ...In this paper, the feasibility study of chemical flooding is carried out for ultra-high porosity and high permeability heavy oil field with permeability higher than 10 μm<sup>2</sup> and porosity greater than 35%. The viscosity-concentration relationship of four kinds of oil flooding systems such as hydrolyzed polyacrylamide, structural polymer A, structural polymer B and gel was studied. The results showed that the viscosity of ordinary polymer and structural polymer B was lower compared with other two types of oil displacement agents, and the viscosity of structural polymer A was higher. The higher the concentration, the higher the viscosity retention rate. The gel system has the highest viscosity and best anti-shear ability. The resistance coefficient and residual resistance coefficient of structural polymer A and gel system were further studied. The results show that permeability, velocity and polymer concentration all affect the resistance coefficient and residual resistance coefficient. From the point of view of resistance establishment ability, it is considered that structural polymer A is not suitable for permeability formation above 10 μm<sup>2</sup>. Gel system has stronger ability to establish resistance coefficient than structural polymer A flooding system, and it is more feasible for formation system with permeability above 10 μm<sup>2</sup>.展开更多
The large current generated by starting directly of super large capacity and high voltage induction motor would have a huge impact on the grid as well as the motor itself.The variation of the power factor and electrom...The large current generated by starting directly of super large capacity and high voltage induction motor would have a huge impact on the grid as well as the motor itself.The variation of the power factor and electromagnetic torque during direct start of motors with different capacity and voltage levels are obtained.Aiming at the problem that the secondary impact of auto-transformer starter is too large and the cost of magnetic control starter is too high,the auto-transformer and magnetic control soft start method of super large capacity and high voltage motor is proposed and the basic working principle is analyzed.The calculation formula of cost for magnetic control soft starter and auto-transformer and magnetic control soft starter is deduced,and specific examples are analyzed and compared.It is concluded that the choice of auto-transformer with appropriate tapping ratio can greatly reduce the cost of auto-transformer and magnetic control soft starter compared with the other one.Finally,the simulation and experiment results show that the start method can effectively avoid secondary current impact and constrain the motor starting current to less than 2.5 times the rated current.展开更多
Superelevation design can basically be regarded as an important part of highway route design system.In the specific design process,designers need to strictly comply with the requirements of superelevation design speci...Superelevation design can basically be regarded as an important part of highway route design system.In the specific design process,designers need to strictly comply with the requirements of superelevation design specifications to ensure the driving stability of curved road section.However,due to the differences of road operation conditions in different regions of China,there are many uncertain factors in the design of super elevation,resulting in design errors.In order to reduce design errors as much as possible,this paper mainly based on the highway route design,highway route design problems and key measures are summarized for reference.展开更多
This article reviews the history and progress of hybrid rice development. Hybrid rice research was initiated back in 1964, and commercialized in 1976. Three-line and two-line system hybrid rice were developed in 1974 ...This article reviews the history and progress of hybrid rice development. Hybrid rice research was initiated back in 1964, and commercialized in 1976. Three-line and two-line system hybrid rice were developed in 1974 and 1995, respectively. Research on super hybrid rice, which was first launched by Ministry of Agriculture, China in 1996, is discussed, and the great progress of super hybrid rice had been achieved with a new yield record by 15.4 t ha^-1 in the 6.84 ha demonstration location in Xupu, Hunan Province, China in 2014. And the mechanism of heterosis, the techniques of hybrid seed production and the modern field managements in hybrid rice over the past decades are also discussed. Additionally, this article dealt with the intellectual property protection(IPR) and development of hybrid rice seed industry in China. Major factors that constrain hybrid rice development are analyzed and possible solutions to this problems are proposed. Finally, the authors present methods to further increase production yield, and propose an improvement for breeding super high-yielding hybrid rice based on these methods.展开更多
We have developed 32-fiber and 60-fiber super high density multi fiber connector. This 32-fiber connector can be applicable for single-mode fiber and 60-fiber connector for multi-mode fiber. We have also established P...We have developed 32-fiber and 60-fiber super high density multi fiber connector. This 32-fiber connector can be applicable for single-mode fiber and 60-fiber connector for multi-mode fiber. We have also established PC (physical contact) connection technology by optimizing polishing condition and clamping force.展开更多
Background:To evaluate the long-term safety,efficacy,predictability,and stability of implantable collamer lens with a central hole(EVO ICL)implantation for correcting high myopia(HM)and super high myopia(SHM).Methods:...Background:To evaluate the long-term safety,efficacy,predictability,and stability of implantable collamer lens with a central hole(EVO ICL)implantation for correcting high myopia(HM)and super high myopia(SHM).Methods:This prospective study evaluated 83 eyes of 46 patients who were divided into groups based on their spherical equivalent refractive error(SE):HM group(−12 D≤SE<−6 D)and SHM group(SE<−12 D).They were followed up for 5 years after ICL implantation;assessments of uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),manifest refractive error,axial length,intraocular pressure,corneal endothelial cell density,and vault were conducted,and a questionnaire was administered.ResuIts:At 5 years postoperatively,the safety indices of the HM and SHM groups were 1.03±0.10 and 1.32±0.39,and the efficacy indices were 0.83±0.25 and 0.86±0.32,respectively.In the HM group,60.47%and 79.07%of the eyes were within±0.50 D and±1.00 D of the attempted correction,while it was achieved for 22.50%and 47.50%of the eyes in the SHM group,respectively.The SE of the HM group decreased from−9.72±1.41 D preoperatively to 0.04±0.39 D 1 month postoperatively and−0.67±0.57 D 5 years postoperatively,while in the SHM group,it decreased from−15.78±3.06 D preoperatively to−0.69±0.97 D 1 month postoperatively and−1.74±1.19 D 5 years postoperatively.Conclusion:EVO ICL implantation is safe,effective,and predictable for correcting HM and SHM.CDVA improved more after surgery for SHM,but the growth of axial length still needs attention.展开更多
The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthe...The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.展开更多
An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel comput...An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.展开更多
In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in ...In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in which the sound speed could reduce sharply depending on concentration of air, and the shock wave could be caused somewhere in super high flow while the flow velocity reaches or exceeds the sound speed in it. Besides bubble collapse, the correlation between shock wave and cavitation bubble collapse should be considered as the main mechanism of serious damage on discharge structures of super high dams.展开更多
Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars(Oryza sativa L. ssp. japonica) in ...Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars(Oryza sativa L. ssp. japonica) in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms(SNPs) and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant's branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.展开更多
In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approac...In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approach to ICF,powerful beams of laser light are focused on a small spherical pellet containing micrograms of deuterium and tritium.The rapid heating caused by the laser“driver”makes the outer layer of the target explode.In keeping with Isaac Newton’s Third Law“For every action,there is an equal and opposite reaction”,the remaining portion of the target is driven inwards in a rocket-like implosion,causing compression of the fuel inside the capsule and the formation of a shock wave,which further heats the fuel in the very center and results in a self-sustaining burn.The fusion burn propagates outward through the cooler,outer regions of the capsule much more rapidly than the capsule can expand.Instead of magnetic fields,the plasma is confined by the inertia of its own mass—hence the term inertial confinement fusion.A similar process can be observed on an astrophysical scale in stars and the terrestrial uber world,that have exhausted their nuclear fuel,hence inertially or gravitationally collapsing and generating a supernova explosion,where the results can easily be converted to induction of energy in control forms for a peaceful purpose(i.e.,inertial fusion reaction)by means of thermal physics and statistical mechanics behavior of an ideal Fermi gas,utilizing Fermi-Degeneracy and Thomas-Fermi theory.The fundamental understanding of thermal physics and statistical mechanics enables us to have a better understanding of Fermi-Degeneracy as well as Thomas-Fermi theory of ideal gas,which results in laser compressing matter to a super high density for purpose of producing thermonuclear energy in way of controlled form for peaceful shape and form i.e.CTR(Controlled Thermonuclear Reaction).In this short review,we have concentrated on Fundamental of State Equations by driving them as it was evaluated in book Statistical Mechanics written by Mayer,J.and Mayer,M.in this article.展开更多
The compressible characteristics in aerated flows at the high velocity ofabout 50m/s were analyzed. Based on the theory of compressible the relations between the sonic speedand shock wave in high-velocity aerated flow...The compressible characteristics in aerated flows at the high velocity ofabout 50m/s were analyzed. Based on the theory of compressible the relations between the sonic speedand shock wave in high-velocity aerated flow were theoretically deduced. And comparisons withmeasured data were made. The theoretical and experimental results show the sonic speed in aeratedflow is merely of the order of several-dozen meters per second, and its minimum value is only 20m/s, which is far much less than that in water or air alone. So high subsonic flow, supersonic flowand transonic flow as well as compression wave, shock wave and expansion wave similarly toaerodnamics may be produced in high velocity aerated flow at the speed of the order of 50m/s. Hencethe influences of these compressible characteristics on high head discharge structures can not beneglected, especially on super high dams over 200m high.展开更多
基金Crop Harvest Technology and Engineering in the Twelfth Five-year Plan (2011BAD16B15-2)Special Foundation of National Modern Maize Industrial Technology System(nycytx-02-17)Cooperation Project of China-International Plant Nutrition Research Institute (NMBF-HenanAU-2009)~~
文摘[Objective] The aim was to explore effects of application postponing of N fertilizer and the mechanism of yield increase in order to provide references for N fertilizer application in a rational way. [Method] In a super-high yielded region of summer maize, field experiment was conducted to research effects of N fertilizer postponing on key enzymes of N metabolism, yield of maize and N fertilizer use. [Result] After application of N fertilizer was postponed, NR, SPS and GS activities of ear-leaf of summer maize increased by 11.99%-34.87%, 8.25%-10.64% and 10.00%- 16.81% on the 28^th d of silking; content of soluble sugar in leaves enhanced signifi- cantly and accumulated nitrogen increased by 5.00%-9.74% in mature stage. The postponing fertilization of "30% of fertilizer in seedling stage+30% of fertilizer in flare- opening stage+40% of fertilizer in silking stage meets N demands of summer maize in late growth period. Compared with conventional fertilization, the maize yield, agro- nomic efficiency and use of N fertilizer all improved by 5.05%, 1.75 kg/kg and 6.87%, respectively, after application postponed. [Conclusion] Application postponing of N fertilizer maintains activity of NR, GS and SPS higher and coordinates metabolism of C and N in late growth period, to further improve yield of maize.
基金supported by the Key Project of Shandong Agriculture: Breeding Technology Research of Super Wheat for High Yield and High Qulity, China([2006]6), the Opening Foundation of the State Key Laboratory of Crop Biology, China (2008KF03)the Postdoctor Innovative Foundation of Shandong Province, China (200802009)+2 种基金the National Basic Re-search of China (973 Program, 2009CB118500)the National Natural Science Foundation of China(30871458)the Program for Changjiang Scholarsand Innovative Research Team in University, China(IRT0635)
文摘The mechanism of high yield of winter wheat in the field at late growth period was investigated by measuring the photosynthetic characteristics of photosystem Ⅱ (PSⅡ) and xanthophylls cycle, which could provide physiological reference for breeding. Weimai 8 (W8), a super high yield cultivar, and Lumai 14 (L14), a control cultivar were object. The photosynthetic rate (Pn), parameters of chlorophyll fluorescence and chlorophyll content were measured. The Pn, maximum photochemical efficiency of PSII (Fv/Fm), quantum yield of PSII electron transport (ΦPSⅡ), efficiency of excitation energy capture by open PSII reaction centers (Fv'/Fm'), and photochemical quenching coefficient (qP) were higher in Weimai 8 compared to that in Lumai 14, a commercial high yield cultivar. Furthermore, Weirnai 8 showed a lower non- photochemical quenching coefficient and a lower de-epoxidized ratio of the xanthophyll cycle pigments than of Lumai 14 at late growth period. At mature stage, chlorophyll content of different leaves decreased both in Weimai 8 and Lumai 14. Chlorophyll content in flag, second and third leaf from the top of plant decreased more in Lumai 14 than in Weimai 8. These results suggested that Weimai 8 had more antenna pigments to absorb light energy, and had higher photosynthetic capability and photochemical efficiency of PSⅡ. The yield of Weimai 8 was also higher than that of Lumai 14.
文摘As a structural material with low density and high strength, super-highstrength aluminum alloys have a future for wide application. However, its poor stress corrosionresistance (SCC) restricts further development. In present, retrogression and re-ageing (RRA)treatment, which can improve both strength and SCCR of 7XXX series alloy, is a best method to solvethis problem. The effect of RRA treatment on the microstructure evolution of a new type lowfrequency electric-magnetic casting Al-9.OZn-2.45Mg-2.2Cu-0.15Zr alloy was investigated using DSCand TEM technologies. The results show that the typical microstructure of the alloy at T6 conditionis characterized by both fine eta' and GP zone homogeneously distributed in the matrix andcontinuous r) particles occurred on the grain-boundary. After RRA treatment, the matrixprecipitations are mainly fine and dispersed eta' and eta phases, being coarser and more stable thanthat from T6 temper. While, the grain-boundary microstructure is very close to that resulting fromT73 temper. High retrogression temperature and long retrogression time leads to a more stablemicrostructure after re-ageing.
基金Projects 40572095 supported by NSFC and 20060290503 by China Ministry of Education
文摘Super-high sulfur coal resultes in serious coal-derived pollution but might have a particular genesis. Thus,a columnar section of an Early Permian Liangshan Formation coal seam. weight average sulfur content 5.80%,from Kaili,eastern Guizhou,was studied using the methods of coal petrology and geochemistry. The results show that the seam was apparently formed in seawater-effected peat bogs that developed in two distinct stages. During the first stage various layers were formed in a supratidal bog and have a composition characteristic of a bog with a gradually decreasing sea-water effect,decreasing water dynamics,and an increasingly reductive environment. Layers in the upper seam formed during a second stage in an intertidal bog. These layers are very high in total and inorganic sulfur,the ratios of or-ganic/inorganic sulfur and V/I drop,they are high in coal ash yield and have a high ash component index,considerable barkinite,oxidized and detrital macerals,have a porphyroclatic micro-structure and are rich in pyrite,all of which indi-cate the coal-forming environment had higher oxidation potential,strong and roiling water dynamics,and intermittent exposure to a sulfur rich environment.
文摘Some super high arch dams ( SHADs), like Xiluodu Arch Dam, after their heights reaching the magnitude of 300 m, confront lots of technical challenges in design and construction. Several crucial technologies of 6 SHADs will be reviewed and discussed in this and consecutive papers, including Xiluodu, Jinping I in China, Baktiary in Iran, ete. , on the topics of the research method, criterion for evaluation and engineering application of dam safety analysis and evaluation, reasonable dam base interface, dam shape optimization, comprehensive treatments of complex foundation, anti-seismic engineering, dam construction material, concrete placement and temperature control, instrumentation and monitoring of dam operation, etc. This paper will mainly focus on the overall safety of SHADs, reasonable dam base interface analysis and evaluation and their engineering application.
文摘This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.
文摘In this paper, the feasibility study of chemical flooding is carried out for ultra-high porosity and high permeability heavy oil field with permeability higher than 10 μm<sup>2</sup> and porosity greater than 35%. The viscosity-concentration relationship of four kinds of oil flooding systems such as hydrolyzed polyacrylamide, structural polymer A, structural polymer B and gel was studied. The results showed that the viscosity of ordinary polymer and structural polymer B was lower compared with other two types of oil displacement agents, and the viscosity of structural polymer A was higher. The higher the concentration, the higher the viscosity retention rate. The gel system has the highest viscosity and best anti-shear ability. The resistance coefficient and residual resistance coefficient of structural polymer A and gel system were further studied. The results show that permeability, velocity and polymer concentration all affect the resistance coefficient and residual resistance coefficient. From the point of view of resistance establishment ability, it is considered that structural polymer A is not suitable for permeability formation above 10 μm<sup>2</sup>. Gel system has stronger ability to establish resistance coefficient than structural polymer A flooding system, and it is more feasible for formation system with permeability above 10 μm<sup>2</sup>.
基金This work was supported in part by the National Key Research and Development Program of China under Grant 2017YFB0902904,in part by the Natural Science Foundation of Hubei Province under Grant 2016CFB448,and in part by the Shenzhen City Science and Technology Innovation Plan under Grant JCYJ20170306170937861,and in part by Wuhan City Science and Technology Program under Grant 2016070204020165.
文摘The large current generated by starting directly of super large capacity and high voltage induction motor would have a huge impact on the grid as well as the motor itself.The variation of the power factor and electromagnetic torque during direct start of motors with different capacity and voltage levels are obtained.Aiming at the problem that the secondary impact of auto-transformer starter is too large and the cost of magnetic control starter is too high,the auto-transformer and magnetic control soft start method of super large capacity and high voltage motor is proposed and the basic working principle is analyzed.The calculation formula of cost for magnetic control soft starter and auto-transformer and magnetic control soft starter is deduced,and specific examples are analyzed and compared.It is concluded that the choice of auto-transformer with appropriate tapping ratio can greatly reduce the cost of auto-transformer and magnetic control soft starter compared with the other one.Finally,the simulation and experiment results show that the start method can effectively avoid secondary current impact and constrain the motor starting current to less than 2.5 times the rated current.
文摘Superelevation design can basically be regarded as an important part of highway route design system.In the specific design process,designers need to strictly comply with the requirements of superelevation design specifications to ensure the driving stability of curved road section.However,due to the differences of road operation conditions in different regions of China,there are many uncertain factors in the design of super elevation,resulting in design errors.In order to reduce design errors as much as possible,this paper mainly based on the highway route design,highway route design problems and key measures are summarized for reference.
基金supported by the National Natural Science Foundation of China(31271659)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD04B10 2011BAD16B01, 2013BAD07B14)
文摘This article reviews the history and progress of hybrid rice development. Hybrid rice research was initiated back in 1964, and commercialized in 1976. Three-line and two-line system hybrid rice were developed in 1974 and 1995, respectively. Research on super hybrid rice, which was first launched by Ministry of Agriculture, China in 1996, is discussed, and the great progress of super hybrid rice had been achieved with a new yield record by 15.4 t ha^-1 in the 6.84 ha demonstration location in Xupu, Hunan Province, China in 2014. And the mechanism of heterosis, the techniques of hybrid seed production and the modern field managements in hybrid rice over the past decades are also discussed. Additionally, this article dealt with the intellectual property protection(IPR) and development of hybrid rice seed industry in China. Major factors that constrain hybrid rice development are analyzed and possible solutions to this problems are proposed. Finally, the authors present methods to further increase production yield, and propose an improvement for breeding super high-yielding hybrid rice based on these methods.
文摘We have developed 32-fiber and 60-fiber super high density multi fiber connector. This 32-fiber connector can be applicable for single-mode fiber and 60-fiber connector for multi-mode fiber. We have also established PC (physical contact) connection technology by optimizing polishing condition and clamping force.
基金supported by National Natural Science Foundation of China(Grant No.81770955)Joint Research Project of New Frontier Technology in municipal hospitals(Grant No.SHDC12018103)+3 种基金Project of Shanghai Science and Technology(Grant No.20410710100)Major Clinical Research Project of Shanghai Shenkang Hospital Development Center(Grant No.SHDC-2020CR1043B)Project of Shanghai Xuhui District Science and Technology(Grant No.2020-015)Shanghai Science and Technology Commission(Grant No.19140900700).
文摘Background:To evaluate the long-term safety,efficacy,predictability,and stability of implantable collamer lens with a central hole(EVO ICL)implantation for correcting high myopia(HM)and super high myopia(SHM).Methods:This prospective study evaluated 83 eyes of 46 patients who were divided into groups based on their spherical equivalent refractive error(SE):HM group(−12 D≤SE<−6 D)and SHM group(SE<−12 D).They were followed up for 5 years after ICL implantation;assessments of uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),manifest refractive error,axial length,intraocular pressure,corneal endothelial cell density,and vault were conducted,and a questionnaire was administered.ResuIts:At 5 years postoperatively,the safety indices of the HM and SHM groups were 1.03±0.10 and 1.32±0.39,and the efficacy indices were 0.83±0.25 and 0.86±0.32,respectively.In the HM group,60.47%and 79.07%of the eyes were within±0.50 D and±1.00 D of the attempted correction,while it was achieved for 22.50%and 47.50%of the eyes in the SHM group,respectively.The SE of the HM group decreased from−9.72±1.41 D preoperatively to 0.04±0.39 D 1 month postoperatively and−0.67±0.57 D 5 years postoperatively,while in the SHM group,it decreased from−15.78±3.06 D preoperatively to−0.69±0.97 D 1 month postoperatively and−1.74±1.19 D 5 years postoperatively.Conclusion:EVO ICL implantation is safe,effective,and predictable for correcting HM and SHM.CDVA improved more after surgery for SHM,but the growth of axial length still needs attention.
文摘The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.
文摘An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.
基金Project supported by the National Natural Science Foundation of China.(No.59479009)
文摘In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in which the sound speed could reduce sharply depending on concentration of air, and the shock wave could be caused somewhere in super high flow while the flow velocity reaches or exceeds the sound speed in it. Besides bubble collapse, the correlation between shock wave and cavitation bubble collapse should be considered as the main mechanism of serious damage on discharge structures of super high dams.
基金supported by the National Natural Science Foundation of China (31371587 and 31430062)the Cultivation Plan for Youth Agricultural Science and Technology Innovative Talents of Liaoning Province (2014046)+1 种基金the China Postdoctoral Science Foundation Grant (2014M560221)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT), China
文摘Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars(Oryza sativa L. ssp. japonica) in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms(SNPs) and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant's branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.
文摘In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approach to ICF,powerful beams of laser light are focused on a small spherical pellet containing micrograms of deuterium and tritium.The rapid heating caused by the laser“driver”makes the outer layer of the target explode.In keeping with Isaac Newton’s Third Law“For every action,there is an equal and opposite reaction”,the remaining portion of the target is driven inwards in a rocket-like implosion,causing compression of the fuel inside the capsule and the formation of a shock wave,which further heats the fuel in the very center and results in a self-sustaining burn.The fusion burn propagates outward through the cooler,outer regions of the capsule much more rapidly than the capsule can expand.Instead of magnetic fields,the plasma is confined by the inertia of its own mass—hence the term inertial confinement fusion.A similar process can be observed on an astrophysical scale in stars and the terrestrial uber world,that have exhausted their nuclear fuel,hence inertially or gravitationally collapsing and generating a supernova explosion,where the results can easily be converted to induction of energy in control forms for a peaceful purpose(i.e.,inertial fusion reaction)by means of thermal physics and statistical mechanics behavior of an ideal Fermi gas,utilizing Fermi-Degeneracy and Thomas-Fermi theory.The fundamental understanding of thermal physics and statistical mechanics enables us to have a better understanding of Fermi-Degeneracy as well as Thomas-Fermi theory of ideal gas,which results in laser compressing matter to a super high density for purpose of producing thermonuclear energy in way of controlled form for peaceful shape and form i.e.CTR(Controlled Thermonuclear Reaction).In this short review,we have concentrated on Fundamental of State Equations by driving them as it was evaluated in book Statistical Mechanics written by Mayer,J.and Mayer,M.in this article.
基金This work was supported by the State-Key Laboratory of High-Speed Hydraulics at Sichuan University.
文摘The compressible characteristics in aerated flows at the high velocity ofabout 50m/s were analyzed. Based on the theory of compressible the relations between the sonic speedand shock wave in high-velocity aerated flow were theoretically deduced. And comparisons withmeasured data were made. The theoretical and experimental results show the sonic speed in aeratedflow is merely of the order of several-dozen meters per second, and its minimum value is only 20m/s, which is far much less than that in water or air alone. So high subsonic flow, supersonic flowand transonic flow as well as compression wave, shock wave and expansion wave similarly toaerodnamics may be produced in high velocity aerated flow at the speed of the order of 50m/s. Hencethe influences of these compressible characteristics on high head discharge structures can not beneglected, especially on super high dams over 200m high.