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Production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains 被引量:2
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作者 李新社 陆步诗 唐伟 《Journal of Central South University》 SCIE EI CAS 2011年第5期1738-1743,共6页
Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The singl... Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1:1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains is possible. The research provides a new idea for the reuse of Daqu distiller's grains and also provides a new way for the development of microbial oils. 展开更多
关键词 Daqu distiller's grains Trichoderma.koningii Trichosporon cutaneum CO-FERMENTATION microbial oils
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Cereal Grains:Their Impacts on Health and Food Safety
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作者 P Rayas-Duarte J Uriyapongson 《食品科学》 EI CAS CSCD 北大核心 2006年第11期586-591,共6页
Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive ev... Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive evidence suggests the antioxidants that are present in the grains are the likely source of benefits. These activities or properties might protect against coronary heart disease and diabetes. The relationships of complex carbohydrates,whole grain products and the prevention of diseases,including type2 diabetes mellitus and coronary heart disease continue to challenge the scientific community. Though cereal grains contribute to a healthy diet there are some people that can not tolerate the proteins present in the grain. This can lead to food allergies and when severe can be diagnosed as celiac disease. 展开更多
关键词 CHD Cereal grains HIGH
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Atomic-scale simulation of nano-grains:structure and diffusion properties 被引量:1
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作者 WEN Yu-hua CHEN Zheng-zheng +1 位作者 WANG Chong-yu ZHU Ru-zeng 《原子与分子物理学报》 CAS CSCD 北大核心 2003年第2期149-152,共4页
Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of ... Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of grain size on structure and diffusion properties of the nanograins. The results reveal that as the grain size is reduced, the fraction of grain surface increases significantly, and the surface width is approximately constant; the mean atomic energy of the surface increases distinctly, but that of the grain interior varies insignificantly; the diffusion coefficient is increased sharply, and the relation of the diffusion coefficient and the grain size is close to exponential relation below 10 nm. 展开更多
关键词 Nano grain STRUCTURE Diffustion property Molecular dynamics simulation
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Cryogenic forging effects and mechanisms on surface coarse grain microstructure in H-shaped 7050 aluminum forgings
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作者 ZHAO Zi-han YI You-ping +2 位作者 HU Jian-liang HUANG Shi-quan HE Hai-lin 《Journal of Central South University》 2025年第6期2009-2021,共13页
This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace appl... This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace applications.The PCF process,utilizing cryogenic deformation,significantly refines the coarse grains at the surface of the forgings,resulting in a finer and more uniform microstructure,thereby effectively addressing the issue of surface coarse grains associated with traditional methods.The findings indicate that the PCF process can accumulate higher stored energy,facilitating static recrystallization(SRX)during subsequent heat treatment and enhancing the microstructural uniformity.Utilizing various analytical techniques,including optical microscopy(OM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).This study reveals the superiority of the PCF process in terms of strain accumulation,dislocation density,and grain refinement.In conclusion,this method offers advantages in enhancing the performance and microstructural uniformity of 7050 aluminum forgings,presenting new opportunities for applications in the aluminum forging industry. 展开更多
关键词 7050 aluminum alloy cryogenic forging coarse grains dislocation density stored energy
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Effect of grain refinement on the corrosion behavior of Zr alloys in fluorinated nitric acid
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作者 XIE Yu-fei WANG Yan-fei +4 位作者 SONG Gui-kang YU Qi-fan LU Xiao-peng LI Jin-shan WANG Xian-zong 《Journal of Central South University》 2025年第5期1614-1629,共16页
The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exp... The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exposure time,F−concentration,and solution temperatures,of Zr alloys with different grain sizes is ascertained.The results confirm that refining the grain size can effectively enhance the short-time corrosion properties of Zr alloy in HNO_(3) with F−.The fine grained Zr alloy(~10μm in diameter)consistently exhibits a lower corrosion current density,ranging from 18%to 46%lower than that of the coarse-grained Zr alloy(~44μm).The enhanced corrosion resistance is attributed to the high density grain boundaries,which promote oxide stability,and accelerate the creation of the protective layer.The high corrosion rate and pseudo-passivation behavior of Zr alloys in fluorinated nitric acid originate from the accelerated“dissolution-passivation”of the oxide film.However,the grain refinement does not provide enduring anti-corrosion for Zr alloys.To meet the operation of spent fuel reprocessing,additional systematic efforts are required to evaluate the long term effect of grain refinement. 展开更多
关键词 zirconium alloys CORROSION grain size fluoride ions nitric acid
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Grain boundary precipitate induced PFZ formation to improve the ductility of extruded Mg-Gd-Y-Nd-Zr alloy after ageing
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作者 GAO Ze-xi LIU Chu-ming +4 位作者 JIANG Shu-nong YANG Da-ling WAN Ying-chun GAO Yong-hao CHEN Zhi-yong 《Journal of Central South University》 2025年第3期693-705,共13页
An increase in RE element content in Mg alloys promotes the grain boundary precipitate,which affects the mechanical properties.However,the influence of grain boundary precipitates on microstructure of Mg-RE alloys dur... An increase in RE element content in Mg alloys promotes the grain boundary precipitate,which affects the mechanical properties.However,the influence of grain boundary precipitates on microstructure of Mg-RE alloys during ageing and their role on ductility of the aged alloy is unclear.In this work,hot extrusion and ageing treatment were performed for Mg-9Gd-2Y-xNd-0.2Zr(x=1 wt.%and 3 wt.%)alloys,and grain boundary precipitates were formed in the extruded Mg-9Gd-2Y-3Nd-0.2Zr alloy due to the increase of Nd content.The extruded alloys exhibit a complete dynamic recrystallization(DRX)microstructure and a texture with the<0001>orientation parallel to the extrusion direction(ED).In addition,a large amount of fiber microstructures distributed by the second phase along the ED were formed in the Mg-9Gd-2Y-3Nd-0.2Zr alloy,while only a small amount of the second phase was observed in the Mg-9Gd-2Y-1Nd-0.2Zr alloy.After ageing treatment,a large amount ofβ'phase precipitated inside the grains.The strength of the Mg-9Gd-2Y-1Nd-0.2Zr alloy increased from 202 MPa to 275 MPa but the elongation decreased from 12.8%to 2.6%,and the strength of the Mg-9Gd-2Y-3Nd-0.2Zr alloy increased from 212 MPa to 281 MPa but the elongation decreased from 13.7%to 6.2%.Among them,the Mg-9Gd-2Y-3Nd-0.2Zr alloy showed good overall mechanical properties,especially the elongation of the aged alloy was 58%higher than that of the Mg-9Gd-2Y-1Nd-0.2Zr alloy.The increase in ductility of the aged Mg-9Gd-2Y-3Nd-0.2Zr alloy attributed to the grain boundary precipitate promotes the formation of a large number of precipitation free zones(PFZs)with widths of 130-150 nm during ageing treatment. 展开更多
关键词 Mg alloy grain boundary precipitate precipitation free zone DUCTILITY
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Reverse design of solid propellant grain based on deep learning:Imaging internal ballistic data
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作者 Lin Sun Xiangyu Peng +4 位作者 Yang Liu Shu Long Weihua Hui Ran Wei Futing Bao 《Defence Technology(防务技术)》 2025年第8期374-385,共12页
The reverse design of solid rocket motor(SRM)propellant grain involves determining the grain geometry to closely match a predefined internal ballistic curve.While existing reverse design methods are feasible,they ofte... The reverse design of solid rocket motor(SRM)propellant grain involves determining the grain geometry to closely match a predefined internal ballistic curve.While existing reverse design methods are feasible,they often face challenges such as lengthy computation times and limited accuracy.To achieve rapid and accurate matching between the targeted ballistic curve and complex grain shape,this paper proposes a novel reverse design method for SRM propellant grain based on time-series data imaging and convolutional neural network(CNN).First,a finocyl grain shape-internal ballistic curve dataset is created using parametric modeling techniques to comprehensively cover the design space.Next,the internal ballistic time-series data is encoded into three-channel images,establishing a potential relationship between the ballistic curves and their image representations.A CNN is then constructed and trained using these encoded images.Once trained,the model enables efficient inference of propellant grain dimensions from a target internal ballistic curve.This paper conducts comparative experiments across various neural network models,validating the effectiveness of the feature extraction method that transforms internal ballistic time-series data into images,as well as its generalization capability across different CNN architectures.Ignition tests were performed based on the predicted propellant grain.The results demonstrate that the relative error between the experimental internal ballistic curves and the target curves is less than 5%,confirming the validity and feasibility of the proposed reverse design methodology. 展开更多
关键词 SRM Propellant grain reverse design Time-series data imaging CNN
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Effect of post weld heat treatment on grain boundary character distribution and corrosion resistance of friction stir welded armourgrade nickel and molybdenum-free high-nitrogen austenitic stainless steel
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作者 Arun Kumar Gurrala Raffi Mohammed G Madhusudhan Reddy 《Defence Technology(防务技术)》 2025年第9期246-261,共16页
This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-... This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications. 展开更多
关键词 Nickel and molybdenum free high-nitrogen austenitic stainless steel Friction stir welding Post-weld heat treatment Electron backscattered diffraction Microstructural gradients Pitting corrosion resistance Coincident site lattice Grain boundary characteristic distribution
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流密码算法Grain的立方攻击 被引量:12
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作者 宋海欣 范修斌 +1 位作者 武传坤 冯登国 《软件学报》 EI CSCD 北大核心 2012年第1期171-176,共6页
Dinur和Shamir在2009年欧洲密码年会上提出了立方攻击的密码分析方法.Grain算法是欧洲序列密码工程eSTREAM最终入选的3个面向硬件实现的流密码算法之一,该算法密钥长度为80比特,初始向量(initialvector,简称IV)长度为64比特,算法分为初... Dinur和Shamir在2009年欧洲密码年会上提出了立方攻击的密码分析方法.Grain算法是欧洲序列密码工程eSTREAM最终入选的3个面向硬件实现的流密码算法之一,该算法密钥长度为80比特,初始向量(initialvector,简称IV)长度为64比特,算法分为初始化过程和密钥流产生过程,初始化过程空跑160拍.利用立方攻击方法对Grain算法进行了分析,在选择IV攻击条件下,若算法初始化过程空跑70拍,则可恢复15比特密钥,并找到了关于另外23比特密钥的4个线性表达式;若算法初始化过程空跑75拍,则可恢复1比特密钥. 展开更多
关键词 eSTREAM工程 流密码算法 GRAIN 立方攻击 密钥恢复
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1Cr18Ni9Ti不锈钢焊接熔池的组织模拟 被引量:4
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作者 赵玉珍 赵海燕 史耀武 《焊接学报》 EI CAS CSCD 北大核心 2008年第12期13-16,共4页
运用晶界演化Grain boundary evolution模型,利用PHOENICS软件计算在不同焊接参数下1Cr18Ni9Ti不锈钢TIG焊接温度场,采用VB语言编制程序模拟了焊缝中柱状晶的生长。结果表明,熔池形状和尺寸影响了柱状晶的生长方向,熔池长宽比越大,晶粒... 运用晶界演化Grain boundary evolution模型,利用PHOENICS软件计算在不同焊接参数下1Cr18Ni9Ti不锈钢TIG焊接温度场,采用VB语言编制程序模拟了焊缝中柱状晶的生长。结果表明,熔池形状和尺寸影响了柱状晶的生长方向,熔池长宽比越大,晶粒的生长方向越垂直于焊缝中心,晶粒短而直;长宽比越小,熔池形状越接近圆形,晶粒的弯曲程度越大,晶粒长而弯。Grain boundary evolution模型能准确地模拟不锈钢焊缝中柱状晶的生长形态,与试验结果中的柱状晶的生长形态吻合较好。 展开更多
关键词 GRAIN BOUNDARY evolution模型 组织模拟 焊缝凝固 不锈钢
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一种针对Grain-v1的新差分错误攻击 被引量:3
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作者 王璐 胡予濮 张振广 《计算机科学》 CSCD 北大核心 2011年第8期80-82,共3页
通过分析流密码算法Grain-v1,提出了一种针对密钥流生成器的差分错误攻击。该攻击利用了前17轮密钥流次数较低的弱点,向LFSR的指定位置引入错误,通过差分得到17个线性无关的线性方程和80个内部状态,只需要猜测62bits的初始内部状态变量... 通过分析流密码算法Grain-v1,提出了一种针对密钥流生成器的差分错误攻击。该攻击利用了前17轮密钥流次数较低的弱点,向LFSR的指定位置引入错误,通过差分得到17个线性无关的线性方程和80个内部状态,只需要猜测62bits的初始内部状态变量就可得到密钥种子。整个过程的计算复杂度为O(274.26)。结果表明,Grain-v1抗差分错误攻击的计算复杂度低于设计者宣称的O(280),也就是说,算法存在安全漏洞。 展开更多
关键词 流密码 GRAIN 差分错误攻击 密钥流
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Hall-Petch relationship in selective laser melting additively manufactured metals:using grain or cell size? 被引量:26
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作者 WANG Yin WANG Yue-ting +4 位作者 LI Rui-di NIU Peng-da WANG Min-bo YUAN Tie-chui LI Kun 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第4期1043-1057,共15页
The mechanical properties of many materials prepared by additive manufacturing technology have been greatly improved.High strength is attributed to grain refinement,formation of high density dislocation and existence ... The mechanical properties of many materials prepared by additive manufacturing technology have been greatly improved.High strength is attributed to grain refinement,formation of high density dislocation and existence of cellular structures with nanoscale during manufacturing.In addition,the super-saturated solid solution of elements in the matrix and the solid solution segregation along the wall of the cellular structures also promote the improvement of strength by enhancing dislocation pinning.Hence,the existence of cellular structure in grains leads to differences in the prediction of material strength by Hall-Petch relationship,and there is no unified calculation method to determine the d value as grain size or cell size.In this work,representative materials including austenite 316L SS were printed by selective laser melting(SLM),and the strength was predicted.The values of cell size and grain size were substituted into Hall-Petch formula,and the results showed that the calculation error for 316L is increased from 4.1%to 11.9%.Therefore,it is concluded that the strength predicted by grain size is more accurate than that predicted by cell size in additive manufacturing materials.When calculating the yield strength of laser additive manufacturing metal materials through the Hall-Petch formula,the grain size should be used as the basis for calculation. 展开更多
关键词 additive manufacturing Hall-Petch relationship grains cellular structures mechanical property
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同步辐射白光形貌术观察LiTaO_3晶体中的小角晶界 被引量:2
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作者 魏景谦 胡小波 +6 位作者 王继扬 尹鑫 郭明 刘宏 刘耀岗 饶晓方 田玉莲 《人工晶体学报》 EI CAS CSCD 北大核心 2000年第S1期250-,共1页
关键词 LiTaO 3 crystal white beam synchrotron radiation topography sub grain bound ary MISORIENTATION
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Grain型级联反馈移存器的非奇异性判定 被引量:2
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作者 王秋艳 金晨辉 《计算机工程》 CAS CSCD 2014年第3期167-170,174,共5页
Grain算法是欧洲序列密码工程eSTREAM最终入选的面向硬件实现的3个序列密码算法之一,它由2个反馈移存器和前馈函数组成,能有效抵御基于线性反馈移存器的序列密码攻击。针对以Grain算法为特例的Grain型级联反馈移存器的非奇异性判定问题... Grain算法是欧洲序列密码工程eSTREAM最终入选的面向硬件实现的3个序列密码算法之一,它由2个反馈移存器和前馈函数组成,能有效抵御基于线性反馈移存器的序列密码攻击。针对以Grain算法为特例的Grain型级联反馈移存器的非奇异性判定问题,给出Grain型级联反馈移存器在初始化过程和密钥流生成过程中,状态刷新变换均构成双射的充分条件,并通过反例说明对于有限域上的Grain型级联反馈移存器,即使所使用的2个移存器都是非奇异的,并且前馈函数满足相应性质,其状态刷新变换仍可能不构成双射。利用Grain v1算法验证了该非奇异性判定结果的正确性。 展开更多
关键词 序列密码 Grain算法 非线性反馈移存器 非奇异性 状态刷新变换 双射性
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流密码Grain v1的密钥恢复攻击及其改进 被引量:1
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作者 杨文峰 胡予濮 高军涛 《西南交通大学学报》 EI CSCD 北大核心 2010年第5期745-750,共6页
为探讨流密码Grain v1的安全性,通过研究Grain v1密钥流生成器的结构,指出了Grain v1密钥流生成器设计的3个弱点,在此基础上提出了一种基于中间状态的流密码Grain v1的密钥恢复攻击.该攻击的计算复杂度和空间复杂度分别等价于Grain v1... 为探讨流密码Grain v1的安全性,通过研究Grain v1密钥流生成器的结构,指出了Grain v1密钥流生成器设计的3个弱点,在此基础上提出了一种基于中间状态的流密码Grain v1的密钥恢复攻击.该攻击的计算复杂度和空间复杂度分别等价于Grain v1密钥流生成器的计算复杂度和空间复杂度.为了抵抗所提出的攻击,对Grain v1密钥流生成器的设计进行了改进.安全性分析表明,改进设计能够抵抗所提出的密钥恢复攻击. 展开更多
关键词 密码分析 线性移位寄存器 布尔函数 流密码Grain
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Effect of low-frequency rotary electromagnetic-field on solidification structure of continuous casting austenitic stainless steel 被引量:3
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作者 周书才 白晨光 +3 位作者 雷亚 任正德 曹鹏军 杨治立 《Journal of Central South University》 SCIE EI CAS 2009年第3期360-364,共5页
To understand the solidification behavior of austenitic stainless steel in rotary electromagnetic-field, the influence of low-frequency rotary electromagnetic-field on solidification structure of austenitic stainless ... To understand the solidification behavior of austenitic stainless steel in rotary electromagnetic-field, the influence of low-frequency rotary electromagnetic-field on solidification structure of austenitic stainless steel in horizontal continuous casting was investigated based on industrial experiments. The results show that the solidification structure of austenitic stainless steel can be remarkably refined, the central porosity and shrinkage cavity can be remarkably decreased, and the equiaxed grains zone are enlarged by means of application of appropriate low-frequency electromagnetic-field parameters. The industrial trials verify that the stirring intensity of austenitic stainless steel should be higher compared with that of plain carbon steel. Electromagnetic stirring affects the macrostructure even if the average magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT) with the frequency of 3-4 Hz. Due to a higher viscosity, rotating speed of molten stainless steel is 20%-30% lower than that of molten carbon steel in the same magnetic flux density. 展开更多
关键词 horizontal continuous casting austenitic stainless steel electromagnetic stirring equiaxed grains central porosity
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Genetic Analysis of Notched Grain in Rice水稻腹缺米的遗传分析 被引量:1
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作者 熊振民 闵绍楷 +1 位作者 孔繁林 朱旭东 《中国水稻科学》 CAS 1986年第1期26-34,共9页
调查了1366份水稻品种和品系,腹缺米的发生频率为5.63%,腹缺米频率与粒重的相关r=+0.6195。1978、1979和1981年,用腹缺米和饱满米配制了17个组合,F_1、F_2和 BF的分析发现,腹缺米受两对显性互补基因控制,环境条件只影响腹缺米的程度。... 调查了1366份水稻品种和品系,腹缺米的发生频率为5.63%,腹缺米频率与粒重的相关r=+0.6195。1978、1979和1981年,用腹缺米和饱满米配制了17个组合,F_1、F_2和 BF的分析发现,腹缺米受两对显性互补基因控制,环境条件只影响腹缺米的程度。这种障碍在早期世代进行连续选择即可消除。 展开更多
关键词 In Genetic Analysis of Notched Grain in Rice
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立方攻击成功率分析
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作者 宋海欣 范修斌 +1 位作者 武传坤 冯登国 《通信学报》 EI CSCD 北大核心 2012年第10期143-148,共6页
在一般随机布尔函数及布尔函数的代数次数或代数标准型项数受限情况下,从理论上分析了立方攻击的成功概率,对立方攻击密码分析方法提供了理论支持。理论结果与对流密码算法Trivium及Grain v1的实验结果是相吻合的。
关键词 立方攻击 成功概率 密钥恢复 GRAIN V1 布尔函数
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MBR处理造纸废水时膜污染的缓解因素 被引量:4
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作者 唐吴晓 李卫星 邢卫红 《膜科学与技术》 CAS CSCD 北大核心 2016年第2期102-107,共6页
随着造纸废水用量的增加,对传统工艺进行改进已经迫在眉睫.膜生物反应器(MBR)作为一种新型高效的处理工艺,能很好地解决这一难题.但是减轻膜污染问题是MBR在造纸废水中广泛应用的关键,本文旨在研究缓解膜污染方法.结果表明,空气效应和... 随着造纸废水用量的增加,对传统工艺进行改进已经迫在眉睫.膜生物反应器(MBR)作为一种新型高效的处理工艺,能很好地解决这一难题.但是减轻膜污染问题是MBR在造纸废水中广泛应用的关键,本文旨在研究缓解膜污染方法.结果表明,空气效应和机械擦洗能有效地缓解膜污染.曝气强度为1 800L/(m^2·h)时能充分实现对膜表面的冲刷,可缓解膜污染.通过向反应器添加支撑介质(颗粒活性炭,GAC),可在低曝气强度下保证跨膜压差(TMP)的变化趋势,进一步减小膜污染和降低能耗. 展开更多
关键词 膜生物反应器 造纸废水 曝气量 GAC(grain active carbon) 膜污染
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Effects of ultrasonic treatment on structure of roll casting aluminum strip 被引量:12
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作者 毛大恒 张云芳 +2 位作者 聂朝辉 刘巧红 钟掘 《Journal of Central South University of Technology》 EI 2007年第3期363-369,共7页
The experiment of ultrasonic treatment of roll casting aluminum strip on plane twin-roll cast-roller with double-heads ultrasonic tools was carried out, and the metallographic structure of the roll casting aluminum st... The experiment of ultrasonic treatment of roll casting aluminum strip on plane twin-roll cast-roller with double-heads ultrasonic tools was carried out, and the metallographic structure of the roll casting aluminum strip treated by ultrasonic was studied. The results show that ultrasonic treatment can refine the grain of the roll casting aluminum strips and make the structure of the strips more homogeneous. The effect is the best when the power of ultrasonic is 300 W and the incident angle of the guide rod is 45、. The mechanism of acoustic cavitations and acoustic flow on grain refinement was also discussed. The heat effect of intensity ultrasonic was studied. The present problems during ultrasonic roll casting process, such as the imperfect cooling system, the inaccurate calculation of ultrasonic energy, and the shape and position of the guide rod to be improved were pointed out. 展开更多
关键词 ULTRASONIC ALUMINUM roll casting metallographic structure grain refinement
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