目的 比较分析不同规格胭脂鱼的营养价值和安全性。方法 以大、中、小3种规格的胭脂鱼为研究对象,采用国家标准方法、高效液相色谱仪、电感耦合等离子质谱仪等测定了基本营养成分、氨基酸组成、重金属含量和兽药残留量,并利用不同的评...目的 比较分析不同规格胭脂鱼的营养价值和安全性。方法 以大、中、小3种规格的胭脂鱼为研究对象,采用国家标准方法、高效液相色谱仪、电感耦合等离子质谱仪等测定了基本营养成分、氨基酸组成、重金属含量和兽药残留量,并利用不同的评价体系比较分析了氨基酸营养和重金属污染情况。结果 胭脂鱼中粗脂肪的含量随重量增大变化显著(P<0.05)(除去最小体重),水分、粗蛋白和粗灰分的变化不明显。不同规格胭脂鱼中均检出17种氨基酸,总量分别为20.70、17.90、20.18 g/100 g,其中谷氨酸平均含量(2.88 g/100 g)最高,其次是天冬氨酸,为1.95 g/100 g,是鲜味氨基酸的主要组成部分,胭脂鱼中富含7种必需氨基酸,含量最高的为赖氨酸,必需氨基酸与非必需氨基酸百分比为64.01%~65.45%,均符合联合国粮农组织和世界卫生组织(Food and Agriculture Organization of the United Nations/World Health Organization, FAO/WHO)推荐的理想蛋白模式;根据氨基酸评分和化学评分结果可知,胭脂鱼第一限制性氨基酸均为甲硫氨酸+胱氨酸;3种规格胭脂鱼的必需氨基酸指数分别为101.99、90.16和98.51。胭脂鱼中Pb、Cd、Cr、无机As和甲基Hg等5种重金属均符合食品安全国家标准,且未检出氯霉素、硝基呋喃等兽药残留。结论 本研究表明胭脂鱼是一种高蛋白低脂肪、氨基酸组成理想、食用安全的高价值鱼类;小规格的胭脂鱼粗蛋白、氨基酸总量和必需氨基酸指数最高,营养价值相对更高,最具食用价值。展开更多
In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the...In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.展开更多
The deoiled asphalt as the carbon source and the ferrocene as the metal source and the catalyst precursor were chosen to synthesize iron-containing carbon microparticles through co-carbonization at the temperature of ...The deoiled asphalt as the carbon source and the ferrocene as the metal source and the catalyst precursor were chosen to synthesize iron-containing carbon microparticles through co-carbonization at the temperature of about 450℃ for 3 h. The resulting products were treated at 2 000 ℃ for 2 h. All samples were examined by high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD）. The results show that the iron particles in the heat-treated material are completely coated by carbon. In addition to the fully filled carbon microparticles as well as hollow carbon ones, also form carbon fibers with hollow centers. The formation mechanism of the as-prepared products was discussed briefly.展开更多
In this paper, we derive the bilinear form for a variable-coefficient Kadomtsev Petviashvili-typed equation. Based on the bilinear form, we obtain the Wronskian determinant solution, which is proved to be indeed an ex...In this paper, we derive the bilinear form for a variable-coefficient Kadomtsev Petviashvili-typed equation. Based on the bilinear form, we obtain the Wronskian determinant solution, which is proved to be indeed an exact solution of this equation through the Wronskian technique. In addition, we testify that this equation can be reduced to a Jacobi identity by considering its solution as a Grammian determinant by means of Pfaffian derivative formulae.展开更多
In this paper, we put our focus on a variable-coe^cient fifth-order Korteweg-de Vries （fKdV） equation, which possesses a great number of excellent properties and is of current importance in physical and engineering ...In this paper, we put our focus on a variable-coe^cient fifth-order Korteweg-de Vries （fKdV） equation, which possesses a great number of excellent properties and is of current importance in physical and engineering fields. Certain constraints are worked out, which make sure the integrability of such an equation. Under those constraints, some integrable properties are derived, such as the Lax pair and Darboux transformation. Via the Darboux transformation, which is an exercisable way to generate solutions in a recursive manner, the one- and two-solitonic solutions are presented and the relevant physical applications of these solitonic structures in some fields are also pointed out.展开更多
For unacceptable computational efficiency and accuracy on the probabilistic analysis of multi-component system with multi-failure modes,this paper proposed multi-extremum response surface method(MERSM).MERSM model was...For unacceptable computational efficiency and accuracy on the probabilistic analysis of multi-component system with multi-failure modes,this paper proposed multi-extremum response surface method(MERSM).MERSM model was established based on quadratic polynomial function by taking extremum response surface model as the sub-model of multi-response surface method.The dynamic probabilistic analysis of an aeroengine turbine blisk with two components,and their reliability of deformation and stress failures was obtained,based on thermal-structural coupling technique,by considering the nonlinearity of material parameters and the transients of gas flow,gas temperature and rotational speed.The results show that the comprehensive reliability of structure is 0.9904 when the allowable deformations and stresses of blade and disk are 4.78×10–3 m and 1.41×109 Pa,and 1.64×10–3 m and 1.04×109 Pa,respectively.Besides,gas temperature and rotating speed severely influence the comprehensive reliability of system.Through the comparison of methods,it is shown that the MERSM holds higher computational precision and speed in the probabilistic analysis of turbine blisk,and MERSM computational precision satisfies the requirement of engineering design.The efforts of this study address the difficulties on transients and multiple models coupling for the dynamic probabilistic analysis of multi-component system with multi-failure modes.展开更多
In this paper, under the Painleve-integrable condition, the auto-Biicklund transformations in different forms for a variable-coefficient Korteweg-de Vries model with physical interests are obtained through various met...In this paper, under the Painleve-integrable condition, the auto-Biicklund transformations in different forms for a variable-coefficient Korteweg-de Vries model with physical interests are obtained through various methods including the Hirota method, truncated Painleve expansion method, extendedvariable-coefficient balancing-act method, and Lax pair. Additionally, the compatibility for the truncated Painleve expansion method and extended variable-coetfficient balancing-act method is testified.展开更多
Rotation is a method to effectively regulate the soil microbial community structure and alleviate the obstacles of continuous planting of eggplant in facilities.High-throughput sequencing technology was used to study ...Rotation is a method to effectively regulate the soil microbial community structure and alleviate the obstacles of continuous planting of eggplant in facilities.High-throughput sequencing technology was used to study the change of beneficial bacteria diversity and structure at the first fruit stage of continuous eggplant rhizosphere soil affected by rotation combined with Bacillus subtilis fertilizer.The result showed that beneficial bacteria in the rhizosphere soil samples of eggplant at the phylum classification level included Actinobacteria,Chloroflexi,Acidobacteria,Planctomycetes and Cyanobacteria.At the level of genus classification,the beneficial bacteria in the rhizosphere soil samples of eggplant were Bacillus,Arthrobacter,Sphingomonas and Streptomyces.The significantly differences were observed in the abundance of soil dominant bacteria and beneficial bacteria at phylum level and genus classification among different treatments.At the phylum level,compared with CK treatment,the relative abundances of Acidobacteria and Proteobacteria in BB treatment were increased by 34.4%and 20.2%,respectively.At the level of genus classification,the beneficial bacterial Arthrobacter abundance in BB treatment was 1.44 times than that of CK treatment and was significantly higher than that in CF treatment.Moreover,the total uptake of N,P and K by eggplants in BB treatment and BFN treatment were 1.68 and 1.35 times than those of CK treatment,respectively.The above results showed that the combined treatment of microbial fertilizer and rotation could increased the soil bacterial community diversity and the abundance of beneficial bacteria in the first fruit stage of eggplant,which indeed enhanced the absorption of N,P and K by continuous eggplant plants,thereby alleviating the obstacles of continuous cropping of eggplant.展开更多
文摘目的 比较分析不同规格胭脂鱼的营养价值和安全性。方法 以大、中、小3种规格的胭脂鱼为研究对象,采用国家标准方法、高效液相色谱仪、电感耦合等离子质谱仪等测定了基本营养成分、氨基酸组成、重金属含量和兽药残留量,并利用不同的评价体系比较分析了氨基酸营养和重金属污染情况。结果 胭脂鱼中粗脂肪的含量随重量增大变化显著(P<0.05)(除去最小体重),水分、粗蛋白和粗灰分的变化不明显。不同规格胭脂鱼中均检出17种氨基酸,总量分别为20.70、17.90、20.18 g/100 g,其中谷氨酸平均含量(2.88 g/100 g)最高,其次是天冬氨酸,为1.95 g/100 g,是鲜味氨基酸的主要组成部分,胭脂鱼中富含7种必需氨基酸,含量最高的为赖氨酸,必需氨基酸与非必需氨基酸百分比为64.01%~65.45%,均符合联合国粮农组织和世界卫生组织(Food and Agriculture Organization of the United Nations/World Health Organization, FAO/WHO)推荐的理想蛋白模式;根据氨基酸评分和化学评分结果可知,胭脂鱼第一限制性氨基酸均为甲硫氨酸+胱氨酸;3种规格胭脂鱼的必需氨基酸指数分别为101.99、90.16和98.51。胭脂鱼中Pb、Cd、Cr、无机As和甲基Hg等5种重金属均符合食品安全国家标准,且未检出氯霉素、硝基呋喃等兽药残留。结论 本研究表明胭脂鱼是一种高蛋白低脂肪、氨基酸组成理想、食用安全的高价值鱼类;小规格的胭脂鱼粗蛋白、氨基酸总量和必需氨基酸指数最高,营养价值相对更高,最具食用价值。
基金Project(2006AA04Z405) supported by the National High Technology Research and Development Program of ChinaProject(3102019) supported by Beijing Municipal Natural Science Foundation,China
文摘In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.
基金National Basic Research Program of China (2004CB217808)National Natural Science Foundation of China (20471041, 90306014)+1 种基金Natural Science Foundation of Shanxi Province (20051018)Shanxi Research Fund for Returned Scholars (200428)
文摘The deoiled asphalt as the carbon source and the ferrocene as the metal source and the catalyst precursor were chosen to synthesize iron-containing carbon microparticles through co-carbonization at the temperature of about 450℃ for 3 h. The resulting products were treated at 2 000 ℃ for 2 h. All samples were examined by high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD）. The results show that the iron particles in the heat-treated material are completely coated by carbon. In addition to the fully filled carbon microparticles as well as hollow carbon ones, also form carbon fibers with hollow centers. The formation mechanism of the as-prepared products was discussed briefly.
基金The project supported by the Key Project of the Ministry of Education under Grant No.106033the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20060006024+2 种基金National Natural Science Foundation of China under Grant Nos.60372095 and 60772023the Open Fund of the State Key Laboratory of Software Development Environment under Grant No.SKLSDE07-001Beijing University of Aeronautics and Astronautics,and the National Basic Research Program of China(973 Program)under Grant No.2005CB321901
文摘In this paper, we derive the bilinear form for a variable-coefficient Kadomtsev Petviashvili-typed equation. Based on the bilinear form, we obtain the Wronskian determinant solution, which is proved to be indeed an exact solution of this equation through the Wronskian technique. In addition, we testify that this equation can be reduced to a Jacobi identity by considering its solution as a Grammian determinant by means of Pfaffian derivative formulae.
基金The project supported by the Key Project of the Chinese Ministry of Education under Grant No.106033the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20060006024+2 种基金Chinese Ministry of Education,the National Natural Science Foundation of China under Grant Nos.60772023 and 60372095the Open Fund of the State Key Laboratory of Software Development Environment under Grant No.SKLSDE-07-001Beijing University of Aeronautics and Astronautics,and by the National Basic Research Program of China(973 Program)under Grant No.2005CB321901
文摘In this paper, we put our focus on a variable-coe^cient fifth-order Korteweg-de Vries （fKdV） equation, which possesses a great number of excellent properties and is of current importance in physical and engineering fields. Certain constraints are worked out, which make sure the integrability of such an equation. Under those constraints, some integrable properties are derived, such as the Lax pair and Darboux transformation. Via the Darboux transformation, which is an exercisable way to generate solutions in a recursive manner, the one- and two-solitonic solutions are presented and the relevant physical applications of these solitonic structures in some fields are also pointed out.
基金Projects (51275138,51605016) supported by the National Natural Science Foundation of ChinaProject (12531109) supported by the Science Foundation of Heilongjiang Provincial Department of Education,ChinaProject supported by Research Start-up Funding of Fudan University,China
文摘For unacceptable computational efficiency and accuracy on the probabilistic analysis of multi-component system with multi-failure modes,this paper proposed multi-extremum response surface method(MERSM).MERSM model was established based on quadratic polynomial function by taking extremum response surface model as the sub-model of multi-response surface method.The dynamic probabilistic analysis of an aeroengine turbine blisk with two components,and their reliability of deformation and stress failures was obtained,based on thermal-structural coupling technique,by considering the nonlinearity of material parameters and the transients of gas flow,gas temperature and rotational speed.The results show that the comprehensive reliability of structure is 0.9904 when the allowable deformations and stresses of blade and disk are 4.78×10–3 m and 1.41×109 Pa,and 1.64×10–3 m and 1.04×109 Pa,respectively.Besides,gas temperature and rotating speed severely influence the comprehensive reliability of system.Through the comparison of methods,it is shown that the MERSM holds higher computational precision and speed in the probabilistic analysis of turbine blisk,and MERSM computational precision satisfies the requirement of engineering design.The efforts of this study address the difficulties on transients and multiple models coupling for the dynamic probabilistic analysis of multi-component system with multi-failure modes.
基金supported by the Key Project of the Ministry of Education under Grant No.106033Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20060006024+2 种基金Ministry of Education,National Natural Science Foundation of China under Grant Nos.60372095 and 60772023Open Fund of the State Key Laboratory of Software Development Environment under Grant No.SKLSDE-07-001Beijing University of Aeronautics and Astronautics,and National Basic Research Program of China (973 Program) under Grant No.2005CB321901
文摘In this paper, under the Painleve-integrable condition, the auto-Biicklund transformations in different forms for a variable-coefficient Korteweg-de Vries model with physical interests are obtained through various methods including the Hirota method, truncated Painleve expansion method, extendedvariable-coefficient balancing-act method, and Lax pair. Additionally, the compatibility for the truncated Painleve expansion method and extended variable-coetfficient balancing-act method is testified.
基金Supported by the Natural Science Joint Guidance Foundation of Heilongjiang Province,China(LH2019C041)Special Fund for Agro-scientific Research in Public Interest,China(201503109)Heilongjiang Natural Science Foundation,China(C2015016)。
文摘Rotation is a method to effectively regulate the soil microbial community structure and alleviate the obstacles of continuous planting of eggplant in facilities.High-throughput sequencing technology was used to study the change of beneficial bacteria diversity and structure at the first fruit stage of continuous eggplant rhizosphere soil affected by rotation combined with Bacillus subtilis fertilizer.The result showed that beneficial bacteria in the rhizosphere soil samples of eggplant at the phylum classification level included Actinobacteria,Chloroflexi,Acidobacteria,Planctomycetes and Cyanobacteria.At the level of genus classification,the beneficial bacteria in the rhizosphere soil samples of eggplant were Bacillus,Arthrobacter,Sphingomonas and Streptomyces.The significantly differences were observed in the abundance of soil dominant bacteria and beneficial bacteria at phylum level and genus classification among different treatments.At the phylum level,compared with CK treatment,the relative abundances of Acidobacteria and Proteobacteria in BB treatment were increased by 34.4%and 20.2%,respectively.At the level of genus classification,the beneficial bacterial Arthrobacter abundance in BB treatment was 1.44 times than that of CK treatment and was significantly higher than that in CF treatment.Moreover,the total uptake of N,P and K by eggplants in BB treatment and BFN treatment were 1.68 and 1.35 times than those of CK treatment,respectively.The above results showed that the combined treatment of microbial fertilizer and rotation could increased the soil bacterial community diversity and the abundance of beneficial bacteria in the first fruit stage of eggplant,which indeed enhanced the absorption of N,P and K by continuous eggplant plants,thereby alleviating the obstacles of continuous cropping of eggplant.
