Shannong 116 is a strong gluten,high yield and multi-resistance wheat variety bred by Shandong Agricultural University,which was approved by the State in 2021 and by Shandong Province in 2022.Shannong 116 combines the...Shannong 116 is a strong gluten,high yield and multi-resistance wheat variety bred by Shandong Agricultural University,which was approved by the State in 2021 and by Shandong Province in 2022.Shannong 116 combines the excellent characteristics of the female parent(strong gluten,disease resistance and early maturity)and the male parent(high yield,water saving and lodging resistance),with a plant height of 76.9 cm,compact plant type,orderly spike layer and good maturity performance,which is suitable for large-scale promotion and market order planting in Huanghuai wheat area.In this paper,the characteristics of Shannong 116 are analyzed,and cultivation technical measures for high yield,high quality and high efficiency are put forward,in order to provide a technical support for the popularization and application of the variety.展开更多
We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnes...We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.展开更多
Objective To evaluate the performance of vaporized hydrogen peroxide (VHP) for the bio-decontamination of the high efficiency particulate air (HEPA) filter unit. Methods Self-made or commercially available bioindi...Objective To evaluate the performance of vaporized hydrogen peroxide (VHP) for the bio-decontamination of the high efficiency particulate air (HEPA) filter unit. Methods Self-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks. Results Due to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H202 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit. Conclusion The HEPA filter unit is more difficult than common enclosure to decontaminate using VHP fumigation. Complete decontamination can be achieved by extending fumigation time. VHP fumigation can be applied for in-situ biodecontamination of the HEPA filter unit as an alternative method to formaldehyde fumigation.展开更多
High temperature air combustion (HTAC) is an attractive technology of saving energy and controlling environment. The mathematical models of turbulent jet flame under the highly preheated air combustion condition are c...High temperature air combustion (HTAC) is an attractive technology of saving energy and controlling environment. The mathematical models of turbulent jet flame under the highly preheated air combustion condition are conducted in the paper. The mixture fraction/probability density function model is employed. The results show that the maximum flame temperature is decreased, the temperature in the HTAC furnace is more uniform than that in the conventional furnace, and the NO x emission is low. The numerical results are partially validated by some experimental measurements.展开更多
The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap...The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite.The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CHNHSnIbased cells greatly.In the paper,we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation.It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM,while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance.By further optimizing the parameters of the doping concentration(1.3 × 10cm~3) and the defect density(1 × 10cm~3) of perovskite absorption layer,and the electron affinity of buffer(4.0 eV) and HTM(2.6 eV),we finally obtain some encouraging results of the Jof 31.59 mA/cm~2,Vof 0.92 V,FF of 79.99%,and PCE of 23.36%.The results show that the lead-free CHNHSnIPSC is a potential environmentally friendly solar cell with high efficiency.Improving the Snstability and reducing the defect density of CHNHSnIare key issues for the future research,which can be solved by improving the fabrication and encapsulation process of the cell.展开更多
A new method of high-gravity combustion synthesis(HGCS)followed by post-treatment(PT)is reported for preparing high-performance high-entropy alloys(HEAs),Cr0.9FeNi2.5V0.2Al0.5 alloy,whereby cheap thermite powder is us...A new method of high-gravity combustion synthesis(HGCS)followed by post-treatment(PT)is reported for preparing high-performance high-entropy alloys(HEAs),Cr0.9FeNi2.5V0.2Al0.5 alloy,whereby cheap thermite powder is used as the raw material.In this process,the HEA melt and the ceramic melt are rapidly formed by a strong exothermic combustion synthesis reaction and completely separated under a high-gravity field.Then,the master alloy is obtained after cooling.Subsequently,the master alloy is sequentially subjected to conventional vacuum arc melting(VAM),homogenization treatment,cold rolling,and annealing treatment to realize a tensile strength,yield strength,and elongation of 1250 MPa,1075 MPa,and 2.9%,respectively.The present method is increasingly attractive due to its low cost of raw materials and the intermediate product obtained without high-temperature heating.Based on the calculation of phase separation kinetics in the high-temperature melt,it is expected that the final alloys with high performance can be prepared directly across master alloys with higher high-gravity coefficients.展开更多
A novel salt-assisted combustion process with ethylene glycol as a fuel and nitrate as an oxidant to synthesize high surface area celia nanopowders was reported. The effects of various tunable conditions, such as fuel...A novel salt-assisted combustion process with ethylene glycol as a fuel and nitrate as an oxidant to synthesize high surface area celia nanopowders was reported. The effects of various tunable conditions, such as fuel-to-oxidant ratio, type of salts, and amount of added salts, on the characteristics of the as-prepared powders were investigated by X-ray diffraction, transmission electron microscopy and BET surface area measurement. A mechanism scheme was proposed to illustrate the possible formation processes of well-dispersed ceria nanoparticles in the salt-assisted combustion synthesis. It was verified that the simple introduction of leachable inert inorganic salts as an excellent agglomeration inhibitor into the redox mixture precursor leads to the formation of well-dispersed ceria particles with particle size in the range of 4 ~6 nm and a drastic increase in the surface area. The presence of KCl results in an over ten-fold increment in specific surface area from 14.10 m^2·g^-1 for the produced ceria powders via the conventional combustion synthesis process to 156.74 m^2·g^-1 for the product by the salt-assisted combustion synthesis process at the same molar ratio of ethylene glycol-nitrate.展开更多
High-density linkage maps are essential tools for genome analysis of various biological traits. Our developed compact multi-gel system, HEGS (high efficiency genome scanning) is a high-throughput and high-cost-perfo...High-density linkage maps are essential tools for genome analysis of various biological traits. Our developed compact multi-gel system, HEGS (high efficiency genome scanning) is a high-throughput and high-cost-performance electrophoresis apparatus. Using this system, a high-density (average interval 2.3 cM) map with 1 065 AFLP and 63 SSR markers was constructed from recombinant inbred lines of a japonica and indica hybrid in just two months of electrophoreses by a single person. More than 50% of the mapped AFLP markers were commonly polymorphic for several combinations between japonica and indica rice and 15% were applicable for genetically closer crosses between upland and lowland types of japonica rice. This system can be used for rapid analyses of all kinds of markers.展开更多
The WC/CoCrFeNiAl0.2 high-entropy alloy(HEA)composites were prepared through high-gravity combustion synthesis.The preparation method is presented below.First,using a designed suitable multiphase thermite system,the m...The WC/CoCrFeNiAl0.2 high-entropy alloy(HEA)composites were prepared through high-gravity combustion synthesis.The preparation method is presented below.First,using a designed suitable multiphase thermite system,the molten CoCrFeNiAl0.2 HEA was fabricated using low-cost metal oxides.The molten HEA was subsequently infiltrated into the WC layer to fabricate WC/CoCrFeNiAl0.2 composites in a highgravity field.The porosity of the WC/CoCrFeNiAl0.2 composites was down-regulated,and their compressive yield strength was up-regulated when the high-gravity field was increased from 600g to 1500g because this infiltration process of a HEA melt into the WC layer is driven by centrifugal force.The WC particles in the composites exhibited a gradient distribution along the direction of the centrifugal force,which was attributed to the combined action of the high-gravity field and the temperature gradient field.The Vickers hardness of the sample was down-regulated from 9.53 to 7.41 GPa along the direction of the centrifugal force.展开更多
There are many reports of devices and fuel additives being able to enhance the performance of automobiles and other forms of transportation that rely upon the combustion of gasoline or diesel fuels. The claims extend ...There are many reports of devices and fuel additives being able to enhance the performance of automobiles and other forms of transportation that rely upon the combustion of gasoline or diesel fuels. The claims extend from increased mileage and power to significant reductions in toxic exhaust emissions of carbon monoxide and unburnt hydrocarbons. Progress towards more widespread applications of means of improving fuel efficiency has been impeded by the lack of a coherent explanation of the mechanism of action. Fuel combustion allows for the conversion of much of the available chemical energy in volatile hydrocarbons to mechanical energy, which moves the pistons within an engine. It is proposed that the amount of chemical energy in hydrocarbons can be increased by the absorption of an environmental force termed KELEA (kinetic energy limiting electrostatic attraction). In addition to providing greater mechanical energy with relatively less heat output, the combustion of KELEA activated fuels proceeds further with less toxic emissions of carbon monoxide and unburnt hydrocarbons from incomplete combustion. KELEA activation of fuels should become standard practice in the transportation industry, with potential additional benefits in slowing the rate of global warming.展开更多
A newly designed grating used in terahertz region is proposed, which is composed of the trapezoidal elements repeated successively along one dimension of the substrate, and uniform interval (the grating period) repe...A newly designed grating used in terahertz region is proposed, which is composed of the trapezoidal elements repeated successively along one dimension of the substrate, and uniform interval (the grating period) repeated along the other dimension. The transmission of the grating owns a designable trapezoidal profile dependent on the geometric dimensions of the element. The far-field diffraction patterns of a designed grating at incident broadband terahertz frequencies, with element dimensions of upper, lower side and period of 50, 250, and 300 μm, respectively, are simulated by the scalar diffraction theory. The simulation results indicate that the terahertz grating exhibits a property of single-order diffraction, and the diffraction efficiency of the first order reaches 6.6%, exceeding that of a traditional sinusoidal amplitude grating with identical period and duty cycle. Owing to the regular architecture and the high single-order diffraction efficiency, the grating is easy to fabricate and shows great potential applications in single-shot spectral measurements of weak broadband terahertz pulse.展开更多
On the basis of the measurement of grains distribution on the grinding wheel surface, many experiential models of the grinding wheel topography were set up. But it is pity that few of them yield practical and valuable...On the basis of the measurement of grains distribution on the grinding wheel surface, many experiential models of the grinding wheel topography were set up. But it is pity that few of them yield practical and valuable achievement as yet. The essential reason is that the common foundation of all these models was based on the actual measurement of specific wheel topography. So it didn’t have universal applicability. Considering that the absolute irregular distribution of grains is not the requirement of the grinding process, contrarily it will bring much negative influence to grinding process. By conversely reasoning, a new conception on the relatively regular and reasonable distribution of grains on the wheel surface in accordance with different machining demands is put forward in this paper, and furthermore a creative idea of optimization design of grinding wheel topography in accordance with machining demands and grinding parameters as well as the optimization of grinding parameters in accordance with machining demands and grinding wheel topography is proposed. In the light of this idea, not only the modeling and simulation of grinding process can be really carried out, but also the optimization of grinding process and the estimation of grinding results can be realized straightway. In conclusion, a superabrasive slotted grinding wheel is designed as a practical application of the optimization model and a creep feed deep grinding experiment is carried out to verify the optimization results.展开更多
Four-hole submerged entry nozzles (SEN) with dif- ferent structures were researched using the water simula- tion test by particle image velocimetry (PIV) and DJSO0 hydraulic measurement system to get suitable SEN ...Four-hole submerged entry nozzles (SEN) with dif- ferent structures were researched using the water simula- tion test by particle image velocimetry (PIV) and DJSO0 hydraulic measurement system to get suitable SEN for high efficiency continuous casting. The influences of the exit area ratio (2: 1:2, 3:2: 3, 1: 1:1 and 1:2: 1), upper guide island angle θ (20°, 40°, 60° and 80°) , and lower guide island angle α (60°, 80°, 100° and 120°) on the vortex position in the mold and fluctuations were researched. The results show that the exit area ratio and the upper and low guide island angles have ob- vious influence on the flow field; the flow field in the mold is suitable at 1:2:1 of the exit area ratio, 80° of upper guide island angle, and 100° of lower guide island angle.展开更多
Measurements of column-averaged dry-air mole fractions of carbon dioxide and carbon monoxide,CO_(2)(XCO_(2))and CO(XCO),were performed throughout 2019 at an urban site in Beijing using a compact Fourier Transform Spec...Measurements of column-averaged dry-air mole fractions of carbon dioxide and carbon monoxide,CO_(2)(XCO_(2))and CO(XCO),were performed throughout 2019 at an urban site in Beijing using a compact Fourier Transform Spectrometer(FTS)EM27/SUN.This data set is used to assess the characteristics of combustion-related CO_(2)emissions of urban Beijing by analyzing the correlated daily anomalies of XCO and XCO_(2)(e.g.,ΔXCO andΔXCO_(2)).The EM27/SUN measurements were calibrated to a 125HR-FTS at the Xianghe station by an extra EM27/SUN instrument transferred between two sites.The ratio ofΔXCO overΔXCO_(2)(ΔXCO:ΔXCO_(2))is used to estimate the combustion efficiency in the Beijing region.A high correlation coefficient(0.86)betweenΔXCO andΔXCO_(2)is observed.The CO:CO_(2)emission ratio estimated from inventories is higher than the observedΔXCO:ΔXCO_(2)(10.46±0.11 ppb ppm^(−1))by 42.54%-101.15%,indicating an underestimation in combustion efficiency in the inventories.DailyΔXCO:ΔXCO_(2)are influenced by transportation governed by weather conditions,except for days in summer when the correlation is low due to the terrestrial biotic activity.By convolving the column footprint[ppm(μmol m-2 s-1)-1]generated by the Weather Research and Forecasting-X-Stochastic Time-Inverted Lagrangian Transport models(WRF-X-STILT)with two fossil-fuel emission inventories(the Multi-resolution Emission Inventory for China(MEIC)and the Peking University(PKU)inventory),the observed enhancements of CO_(2)and CO were used to evaluate the regional emissions.The CO_(2)emissions appear to be underestimated by 11%and 49%for the MEIC and PKU inventories,respectively,while CO emissions were overestimated by MEIC(30%)and PKU(35%)in the Beijing area.展开更多
Diffractive lenses(DLs)can realize high-resolution imaging with light weight and compact size.Conventional DLs suffer large chromatic and off-axis aberrations,which significantly limits their practical applications.Al...Diffractive lenses(DLs)can realize high-resolution imaging with light weight and compact size.Conventional DLs suffer large chromatic and off-axis aberrations,which significantly limits their practical applications.Although many achromatic methods have been proposed,most of them are used for designing small aperture DLs,which have low diffraction efficiencies.In the designing of diffractive achromatic lenses,increasing the aperture and improving the diffraction efficiency have become two of the most important design issues.Here,a novel phase-coded diffractive lens(PCDL)for achromatic imaging with a large aperture and high efficiency is proposed and demonstrated experimentally,and it also possesses wide field-of-view(FOV)imaging at the same time.The phase distribution of the conventional phase-type diffractive lens(DL)is coded with a cubic function to expand both the working bandwidth and the FOV of conventional DL.The proposed phase-type DL is fabricated by using the laser direct writing of grey-scale patterns for a PCDL of a diameter of 10 mm,a focal length of 100 mm,and a cubic phase coding parameter of 30π.Experimental results show that the working bandwidth and the FOV of the PCDL respectively reach 50 nm and 16°with over 8%focusing efficiency,which are in significant contrast to the counterparts of conventional DL and in good agreement with the theoretical predictions.This work provides a novel way for implementing the achromatic,wide FOV,and high-efficiency imaging with large aperture DL.展开更多
High Efficiency Video Coding (HEVC) is the latest international video coding standard, which can provide the similar quality with about half bandwidth compared with its predecessor, H.264/MPEG?4 AVC. To meet the requi...High Efficiency Video Coding (HEVC) is the latest international video coding standard, which can provide the similar quality with about half bandwidth compared with its predecessor, H.264/MPEG?4 AVC. To meet the requirement of higher bit depth coding and more chroma sampling formats, range extensions of HEVC were developed. This paper introduces the coding tools in HEVC range extensions and provides experimental results to compare HEVC range extensions with previous video coding standards. Ex?perimental results show that HEVC range extensions improve coding efficiency much over H.264/MPEG?4 AVC High Predictive profile, especially for 4K sequences.展开更多
High efficiency, stable organic light-emitting diodes (OLEDs) based on 2-pheyl-4'-carbazole-9-H-Thioxanthen-9- one-10, 10-dioxide (TXO-PhCz) with different doping concentration are constructed. The stability of t...High efficiency, stable organic light-emitting diodes (OLEDs) based on 2-pheyl-4'-carbazole-9-H-Thioxanthen-9- one-10, 10-dioxide (TXO-PhCz) with different doping concentration are constructed. The stability of the encap- sulated devices are investigated in detail. The devices with the 10 wt% doped TXO-PhCz emitter layer (EML) show the best performance with a current efficiency of 52.1 cd/A, a power efficiency of 32.71re^W, and an external quantum efficiency (EQE) of 17.7%. The devices based on the lOwt%-doped TXO-PhCz EML show the best operational stability with a half-life time (LTSO) of 8Oh, which is 8 h longer than that of the reference devices based on fac-tris(2-phenylpyridinato)iridium( Ⅲ) (Ir(ppy)a). These indicate excellent stability of TXO-PhCz for redox and oxidation processes under electrical excitation and TXO-PhCz can be potentially used as the emitters for OLEDs with high efficiency and excellent stability. The high-performance device based on TXO-PhCz with high stability can be further improved by the optimization of the encapsulation technology and the development of a new host for TXO-PhCz.展开更多
Through the analysis of the impact of changes in the cotton planting industry on cotton production structure and benefit in Shandong under the national cotton production pattern in past ten years,based on the guarante...Through the analysis of the impact of changes in the cotton planting industry on cotton production structure and benefit in Shandong under the national cotton production pattern in past ten years,based on the guarantee of food security and the overall ecological regional layout of Shandong s agricultural characteristic and advantageous industries,we proposed that through the development of high-quality short-season cotton and the industrial application of high-efficiency technologies,a green and high-efficiency farming system should be established to comprehensively reduce cotton planting costs,improve comparative benefits,and realize green and efficient optimization technologies that unify the stable production of cotton and high-quality cotton supply and the industrial path supported by the new industrial model.It is aimed to speed up the upgrading and transformation of the existing traditional cotton cropping system,reconstruct a ternary structure of grains,economic crops and fodder in the ecological suitable cotton areas and sub-suitable cotton areas in Shandong,and maintain a series of new green and ecological cotton rotation industrial models including the“double security”of the grain and cotton industries,the ecological“double superiority”of "cotton and fodder",and the high-efficiency"double increase"of cotton and garlic,providing a certain foundation for the research on technological integration innovation and industrial structure optimization of the green,efficient and high-quality development and transformation of the cotton industry in Shandong during the"14 th Five-Year Plan"period.展开更多
We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge (1.88 eVil .42 eVil .05 eV/0.67eV) four-junction (4J) solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the...We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge (1.88 eVil .42 eVil .05 eV/0.67eV) four-junction (4J) solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the current limit of the GalnNAs sub cell, we design three kinds of anti-reflection coatings and adjust the base region thickness of the GalnNAs sub cell. Developed by a series of experiments, the external quantum efficiency of the GalnNAs sub cell exceeds 80%, and its current density reaches 11.24 mA/cm2. Therefore the current limit of the 4J solar cell is significantly improved. Moreover, we discuss the difference of test results between 4J and GalnP/GalnAs/Ge solar cells under the 1 sun AMO spectrum.展开更多
基金Supported by Agricultural Improved Variety Engineering Project of Shandong Province"Research on Super Wheat Breeding Technology"(LNLZ[2011]7,[2012]213)National Key Project for the Cultivation of New Varieties of Genetically Modified Organisms"Breeding of New Varieties of Genetically Modified Organisms"(2013ZX08002-003)Science and Technology Innovation Major Project of Tai an City"Breeding and Application of Breakthrough Wheat Varieties with High Yield,Wide Adaptability and Good Quality"(2022NYLZ06).
文摘Shannong 116 is a strong gluten,high yield and multi-resistance wheat variety bred by Shandong Agricultural University,which was approved by the State in 2021 and by Shandong Province in 2022.Shannong 116 combines the excellent characteristics of the female parent(strong gluten,disease resistance and early maturity)and the male parent(high yield,water saving and lodging resistance),with a plant height of 76.9 cm,compact plant type,orderly spike layer and good maturity performance,which is suitable for large-scale promotion and market order planting in Huanghuai wheat area.In this paper,the characteristics of Shannong 116 are analyzed,and cultivation technical measures for high yield,high quality and high efficiency are put forward,in order to provide a technical support for the popularization and application of the variety.
基金Project supported by the Young Scientist Fund of the National Natural Science Foundation of China(Grant No.51006118)
文摘We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.
基金supported by the Research Fund from the Ministry of Science and Technology of the People’s Republic of China, 2009ZX10004-502 and 2009ZX10004-709
文摘Objective To evaluate the performance of vaporized hydrogen peroxide (VHP) for the bio-decontamination of the high efficiency particulate air (HEPA) filter unit. Methods Self-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks. Results Due to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H202 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit. Conclusion The HEPA filter unit is more difficult than common enclosure to decontaminate using VHP fumigation. Complete decontamination can be achieved by extending fumigation time. VHP fumigation can be applied for in-situ biodecontamination of the HEPA filter unit as an alternative method to formaldehyde fumigation.
文摘High temperature air combustion (HTAC) is an attractive technology of saving energy and controlling environment. The mathematical models of turbulent jet flame under the highly preheated air combustion condition are conducted in the paper. The mixture fraction/probability density function model is employed. The results show that the maximum flame temperature is decreased, the temperature in the HTAC furnace is more uniform than that in the conventional furnace, and the NO x emission is low. The numerical results are partially validated by some experimental measurements.
基金supported by the Graduate Student Education Teaching Reform Project,China(Grant No.JG201512)the Young Teachers Research Project of Yanshan University,China(Grant No.13LGB028)
文摘The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite.The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CHNHSnIbased cells greatly.In the paper,we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation.It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM,while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance.By further optimizing the parameters of the doping concentration(1.3 × 10cm~3) and the defect density(1 × 10cm~3) of perovskite absorption layer,and the electron affinity of buffer(4.0 eV) and HTM(2.6 eV),we finally obtain some encouraging results of the Jof 31.59 mA/cm~2,Vof 0.92 V,FF of 79.99%,and PCE of 23.36%.The results show that the lead-free CHNHSnIPSC is a potential environmentally friendly solar cell with high efficiency.Improving the Snstability and reducing the defect density of CHNHSnIare key issues for the future research,which can be solved by improving the fabrication and encapsulation process of the cell.
基金the National Natural Science Foundation of China(No.51702332)the Key Research Projects in Gansu Province(No.17YF1GA020)the CAS Key Laboratory of Cryogenics,Technical Institute of Physics and Chemistry(Youth Innovation Fund No.CRYOQN201705).
文摘A new method of high-gravity combustion synthesis(HGCS)followed by post-treatment(PT)is reported for preparing high-performance high-entropy alloys(HEAs),Cr0.9FeNi2.5V0.2Al0.5 alloy,whereby cheap thermite powder is used as the raw material.In this process,the HEA melt and the ceramic melt are rapidly formed by a strong exothermic combustion synthesis reaction and completely separated under a high-gravity field.Then,the master alloy is obtained after cooling.Subsequently,the master alloy is sequentially subjected to conventional vacuum arc melting(VAM),homogenization treatment,cold rolling,and annealing treatment to realize a tensile strength,yield strength,and elongation of 1250 MPa,1075 MPa,and 2.9%,respectively.The present method is increasingly attractive due to its low cost of raw materials and the intermediate product obtained without high-temperature heating.Based on the calculation of phase separation kinetics in the high-temperature melt,it is expected that the final alloys with high performance can be prepared directly across master alloys with higher high-gravity coefficients.
基金Project supported bythe National Natural Science Foundation of China (50306008) andthefundfromthe Preli minary ResearchProject of General Equipment Ministry (41328030507)
文摘A novel salt-assisted combustion process with ethylene glycol as a fuel and nitrate as an oxidant to synthesize high surface area celia nanopowders was reported. The effects of various tunable conditions, such as fuel-to-oxidant ratio, type of salts, and amount of added salts, on the characteristics of the as-prepared powders were investigated by X-ray diffraction, transmission electron microscopy and BET surface area measurement. A mechanism scheme was proposed to illustrate the possible formation processes of well-dispersed ceria nanoparticles in the salt-assisted combustion synthesis. It was verified that the simple introduction of leachable inert inorganic salts as an excellent agglomeration inhibitor into the redox mixture precursor leads to the formation of well-dispersed ceria particles with particle size in the range of 4 ~6 nm and a drastic increase in the surface area. The presence of KCl results in an over ten-fold increment in specific surface area from 14.10 m^2·g^-1 for the produced ceria powders via the conventional combustion synthesis process to 156.74 m^2·g^-1 for the product by the salt-assisted combustion synthesis process at the same molar ratio of ethylene glycol-nitrate.
文摘High-density linkage maps are essential tools for genome analysis of various biological traits. Our developed compact multi-gel system, HEGS (high efficiency genome scanning) is a high-throughput and high-cost-performance electrophoresis apparatus. Using this system, a high-density (average interval 2.3 cM) map with 1 065 AFLP and 63 SSR markers was constructed from recombinant inbred lines of a japonica and indica hybrid in just two months of electrophoreses by a single person. More than 50% of the mapped AFLP markers were commonly polymorphic for several combinations between japonica and indica rice and 15% were applicable for genetically closer crosses between upland and lowland types of japonica rice. This system can be used for rapid analyses of all kinds of markers.
基金financially supported by the National Key R&D Program of China (No. 2017YFB0310303)the National Natural Science Foundation of China (No. 51702332)the Key Laboratory of Cryogenics, TIPC, CAS (Nos. CRYOQN201705 and CRYOQN201507)
文摘The WC/CoCrFeNiAl0.2 high-entropy alloy(HEA)composites were prepared through high-gravity combustion synthesis.The preparation method is presented below.First,using a designed suitable multiphase thermite system,the molten CoCrFeNiAl0.2 HEA was fabricated using low-cost metal oxides.The molten HEA was subsequently infiltrated into the WC layer to fabricate WC/CoCrFeNiAl0.2 composites in a highgravity field.The porosity of the WC/CoCrFeNiAl0.2 composites was down-regulated,and their compressive yield strength was up-regulated when the high-gravity field was increased from 600g to 1500g because this infiltration process of a HEA melt into the WC layer is driven by centrifugal force.The WC particles in the composites exhibited a gradient distribution along the direction of the centrifugal force,which was attributed to the combined action of the high-gravity field and the temperature gradient field.The Vickers hardness of the sample was down-regulated from 9.53 to 7.41 GPa along the direction of the centrifugal force.
文摘There are many reports of devices and fuel additives being able to enhance the performance of automobiles and other forms of transportation that rely upon the combustion of gasoline or diesel fuels. The claims extend from increased mileage and power to significant reductions in toxic exhaust emissions of carbon monoxide and unburnt hydrocarbons. Progress towards more widespread applications of means of improving fuel efficiency has been impeded by the lack of a coherent explanation of the mechanism of action. Fuel combustion allows for the conversion of much of the available chemical energy in volatile hydrocarbons to mechanical energy, which moves the pistons within an engine. It is proposed that the amount of chemical energy in hydrocarbons can be increased by the absorption of an environmental force termed KELEA (kinetic energy limiting electrostatic attraction). In addition to providing greater mechanical energy with relatively less heat output, the combustion of KELEA activated fuels proceeds further with less toxic emissions of carbon monoxide and unburnt hydrocarbons from incomplete combustion. KELEA activation of fuels should become standard practice in the transportation industry, with potential additional benefits in slowing the rate of global warming.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFB05033)the National Science Instruments Major Project of China(Grant No.2012YQ130125)
文摘A newly designed grating used in terahertz region is proposed, which is composed of the trapezoidal elements repeated successively along one dimension of the substrate, and uniform interval (the grating period) repeated along the other dimension. The transmission of the grating owns a designable trapezoidal profile dependent on the geometric dimensions of the element. The far-field diffraction patterns of a designed grating at incident broadband terahertz frequencies, with element dimensions of upper, lower side and period of 50, 250, and 300 μm, respectively, are simulated by the scalar diffraction theory. The simulation results indicate that the terahertz grating exhibits a property of single-order diffraction, and the diffraction efficiency of the first order reaches 6.6%, exceeding that of a traditional sinusoidal amplitude grating with identical period and duty cycle. Owing to the regular architecture and the high single-order diffraction efficiency, the grating is easy to fabricate and shows great potential applications in single-shot spectral measurements of weak broadband terahertz pulse.
文摘On the basis of the measurement of grains distribution on the grinding wheel surface, many experiential models of the grinding wheel topography were set up. But it is pity that few of them yield practical and valuable achievement as yet. The essential reason is that the common foundation of all these models was based on the actual measurement of specific wheel topography. So it didn’t have universal applicability. Considering that the absolute irregular distribution of grains is not the requirement of the grinding process, contrarily it will bring much negative influence to grinding process. By conversely reasoning, a new conception on the relatively regular and reasonable distribution of grains on the wheel surface in accordance with different machining demands is put forward in this paper, and furthermore a creative idea of optimization design of grinding wheel topography in accordance with machining demands and grinding parameters as well as the optimization of grinding parameters in accordance with machining demands and grinding wheel topography is proposed. In the light of this idea, not only the modeling and simulation of grinding process can be really carried out, but also the optimization of grinding process and the estimation of grinding results can be realized straightway. In conclusion, a superabrasive slotted grinding wheel is designed as a practical application of the optimization model and a creep feed deep grinding experiment is carried out to verify the optimization results.
基金The National Natrual Science Foundation of China(Grant No.51372231)
文摘Four-hole submerged entry nozzles (SEN) with dif- ferent structures were researched using the water simula- tion test by particle image velocimetry (PIV) and DJSO0 hydraulic measurement system to get suitable SEN for high efficiency continuous casting. The influences of the exit area ratio (2: 1:2, 3:2: 3, 1: 1:1 and 1:2: 1), upper guide island angle θ (20°, 40°, 60° and 80°) , and lower guide island angle α (60°, 80°, 100° and 120°) on the vortex position in the mold and fluctuations were researched. The results show that the exit area ratio and the upper and low guide island angles have ob- vious influence on the flow field; the flow field in the mold is suitable at 1:2:1 of the exit area ratio, 80° of upper guide island angle, and 100° of lower guide island angle.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2017YFB0504000)National Natural Science Foundation of China(Grant No.41875043)+2 种基金the Strategic Priority Research 275 Program of the Chinese Academy of Sciences(Grant No.XDA17010102)External Cooperation Program of the Chinese Academy of Science(Grant No.GJHZ1802)Youth Innovation Promotion Association,CAS.
文摘Measurements of column-averaged dry-air mole fractions of carbon dioxide and carbon monoxide,CO_(2)(XCO_(2))and CO(XCO),were performed throughout 2019 at an urban site in Beijing using a compact Fourier Transform Spectrometer(FTS)EM27/SUN.This data set is used to assess the characteristics of combustion-related CO_(2)emissions of urban Beijing by analyzing the correlated daily anomalies of XCO and XCO_(2)(e.g.,ΔXCO andΔXCO_(2)).The EM27/SUN measurements were calibrated to a 125HR-FTS at the Xianghe station by an extra EM27/SUN instrument transferred between two sites.The ratio ofΔXCO overΔXCO_(2)(ΔXCO:ΔXCO_(2))is used to estimate the combustion efficiency in the Beijing region.A high correlation coefficient(0.86)betweenΔXCO andΔXCO_(2)is observed.The CO:CO_(2)emission ratio estimated from inventories is higher than the observedΔXCO:ΔXCO_(2)(10.46±0.11 ppb ppm^(−1))by 42.54%-101.15%,indicating an underestimation in combustion efficiency in the inventories.DailyΔXCO:ΔXCO_(2)are influenced by transportation governed by weather conditions,except for days in summer when the correlation is low due to the terrestrial biotic activity.By convolving the column footprint[ppm(μmol m-2 s-1)-1]generated by the Weather Research and Forecasting-X-Stochastic Time-Inverted Lagrangian Transport models(WRF-X-STILT)with two fossil-fuel emission inventories(the Multi-resolution Emission Inventory for China(MEIC)and the Peking University(PKU)inventory),the observed enhancements of CO_(2)and CO were used to evaluate the regional emissions.The CO_(2)emissions appear to be underestimated by 11%and 49%for the MEIC and PKU inventories,respectively,while CO emissions were overestimated by MEIC(30%)and PKU(35%)in the Beijing area.
基金the National Natural Science Foundation of China(Grant No.61775154)the Natural Science Foundation of the Jiangsu Higher Education Institutions,China(Grant No.18KJB140015)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe Open Research Fund of CAS Key Laboratory of Space Precision Measurement Technology,China(Grant No.SPMT2021001)。
文摘Diffractive lenses(DLs)can realize high-resolution imaging with light weight and compact size.Conventional DLs suffer large chromatic and off-axis aberrations,which significantly limits their practical applications.Although many achromatic methods have been proposed,most of them are used for designing small aperture DLs,which have low diffraction efficiencies.In the designing of diffractive achromatic lenses,increasing the aperture and improving the diffraction efficiency have become two of the most important design issues.Here,a novel phase-coded diffractive lens(PCDL)for achromatic imaging with a large aperture and high efficiency is proposed and demonstrated experimentally,and it also possesses wide field-of-view(FOV)imaging at the same time.The phase distribution of the conventional phase-type diffractive lens(DL)is coded with a cubic function to expand both the working bandwidth and the FOV of conventional DL.The proposed phase-type DL is fabricated by using the laser direct writing of grey-scale patterns for a PCDL of a diameter of 10 mm,a focal length of 100 mm,and a cubic phase coding parameter of 30π.Experimental results show that the working bandwidth and the FOV of the PCDL respectively reach 50 nm and 16°with over 8%focusing efficiency,which are in significant contrast to the counterparts of conventional DL and in good agreement with the theoretical predictions.This work provides a novel way for implementing the achromatic,wide FOV,and high-efficiency imaging with large aperture DL.
文摘High Efficiency Video Coding (HEVC) is the latest international video coding standard, which can provide the similar quality with about half bandwidth compared with its predecessor, H.264/MPEG?4 AVC. To meet the requirement of higher bit depth coding and more chroma sampling formats, range extensions of HEVC were developed. This paper introduces the coding tools in HEVC range extensions and provides experimental results to compare HEVC range extensions with previous video coding standards. Ex?perimental results show that HEVC range extensions improve coding efficiency much over H.264/MPEG?4 AVC High Predictive profile, especially for 4K sequences.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61420106002,51373189,61178061,and 61227008the Hundred Talents Program of the Chinese Academy of Sciences,the National Basic Research Program of China under Grant No 2014CB932600the Start-Up Fund of the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences
文摘High efficiency, stable organic light-emitting diodes (OLEDs) based on 2-pheyl-4'-carbazole-9-H-Thioxanthen-9- one-10, 10-dioxide (TXO-PhCz) with different doping concentration are constructed. The stability of the encap- sulated devices are investigated in detail. The devices with the 10 wt% doped TXO-PhCz emitter layer (EML) show the best performance with a current efficiency of 52.1 cd/A, a power efficiency of 32.71re^W, and an external quantum efficiency (EQE) of 17.7%. The devices based on the lOwt%-doped TXO-PhCz EML show the best operational stability with a half-life time (LTSO) of 8Oh, which is 8 h longer than that of the reference devices based on fac-tris(2-phenylpyridinato)iridium( Ⅲ) (Ir(ppy)a). These indicate excellent stability of TXO-PhCz for redox and oxidation processes under electrical excitation and TXO-PhCz can be potentially used as the emitters for OLEDs with high efficiency and excellent stability. The high-performance device based on TXO-PhCz with high stability can be further improved by the optimization of the encapsulation technology and the development of a new host for TXO-PhCz.
基金Shandong Provincial Cotton Green,High-yield and Efficient Creation Project(LNMZ[2017]5).
文摘Through the analysis of the impact of changes in the cotton planting industry on cotton production structure and benefit in Shandong under the national cotton production pattern in past ten years,based on the guarantee of food security and the overall ecological regional layout of Shandong s agricultural characteristic and advantageous industries,we proposed that through the development of high-quality short-season cotton and the industrial application of high-efficiency technologies,a green and high-efficiency farming system should be established to comprehensively reduce cotton planting costs,improve comparative benefits,and realize green and efficient optimization technologies that unify the stable production of cotton and high-quality cotton supply and the industrial path supported by the new industrial model.It is aimed to speed up the upgrading and transformation of the existing traditional cotton cropping system,reconstruct a ternary structure of grains,economic crops and fodder in the ecological suitable cotton areas and sub-suitable cotton areas in Shandong,and maintain a series of new green and ecological cotton rotation industrial models including the“double security”of the grain and cotton industries,the ecological“double superiority”of "cotton and fodder",and the high-efficiency"double increase"of cotton and garlic,providing a certain foundation for the research on technological integration innovation and industrial structure optimization of the green,efficient and high-quality development and transformation of the cotton industry in Shandong during the"14 th Five-Year Plan"period.
文摘We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge (1.88 eVil .42 eVil .05 eV/0.67eV) four-junction (4J) solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the current limit of the GalnNAs sub cell, we design three kinds of anti-reflection coatings and adjust the base region thickness of the GalnNAs sub cell. Developed by a series of experiments, the external quantum efficiency of the GalnNAs sub cell exceeds 80%, and its current density reaches 11.24 mA/cm2. Therefore the current limit of the 4J solar cell is significantly improved. Moreover, we discuss the difference of test results between 4J and GalnP/GalnAs/Ge solar cells under the 1 sun AMO spectrum.