We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were use...We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.展开更多
This thesis mainly analyzes the content and form of Robert Morgan's postmodern poem"Mountain Graveyard". With New Criticism's method of close reading, it firstly explores the possible interpretations...This thesis mainly analyzes the content and form of Robert Morgan's postmodern poem"Mountain Graveyard". With New Criticism's method of close reading, it firstly explores the possible interpretations of the poem's content. Then it analyzes the post-modernity due to the poem's form, pointing out that with the unique form breaking traditional poetry's conventions, and the upspring of multiple meanings from the content, this poem presents brilliantly the postmodern spirit, which rejects definite centers and embraces various diversity of meaning.展开更多
In gas metal arc welding(GMAW)process,the short-circuit transition was the most typical transition observed in molten metal droplets.This paper used orthogonal tests to explore the coupling effect law of welding proce...In gas metal arc welding(GMAW)process,the short-circuit transition was the most typical transition observed in molten metal droplets.This paper used orthogonal tests to explore the coupling effect law of welding process parameters on the quality of weld forming under short-circuit transition,the design of 3 factors and 3 levels of a total of 9 groups of orthogonal tests,welding current,welding voltage,welding speed as input parameters:effective area ratio,humps,actual linear power density,aspect ratio,Vickers hardness as output paramet-ers(response targets).Using range analysis and trend charts,we can visually depict the relationship between input parameters and a single output parameter,ultimately determining the optimal process parameters that impact the single output index.Then combined with gray the-ory to transform the three response targets into a single gray relational grade(GRG)for analysis,the optimal combination of the weld mor-phology parameters as follows:welding current 100 A,welding voltage 25 V,welding speed 30 cm/min.Finally,validation experiments were conducted,and the results showed that the error between the gray relational grade and the predicted value was 2.74%.It was observed that the effective area ratio of the response target significantly improved,validating the reliability of the orthogonal gray relational method.展开更多
Whether to adopt the meaning-oriented or form-oriented approach in EFL teaching has been in hot academic debate in the past decades. This paper investigates the literature contribution on these two methods, attempts a...Whether to adopt the meaning-oriented or form-oriented approach in EFL teaching has been in hot academic debate in the past decades. This paper investigates the literature contribution on these two methods, attempts an integration of the two,and introduces a teaching experiment of EFL reading and writing at China Agricultural University.展开更多
For fuzzy systems to be implemented effectively,the fuzzy membership function(MF)is essential.A fuzzy system(FS)that implements precise input and output MFs is presented to enhance the performance and accuracy of sing...For fuzzy systems to be implemented effectively,the fuzzy membership function(MF)is essential.A fuzzy system(FS)that implements precise input and output MFs is presented to enhance the performance and accuracy of single-input single-output(SISO)FSs and introduce the most applicable input and output MFs protocol to linearize the fuzzy system’s output.Utilizing a variety of non-linear techniques,a SISO FS is simulated.The results of FS experiments conducted in comparable conditions are then compared.The simulated results and the results of the experimental setup agree fairly well.The findings of the suggested model demonstrate that the relative error is abated to a sufficient range(≤±10%)and that the mean absolute percentage error(MPAE)is reduced by around 66.2%.The proposed strategy to reduceMAPE using an FS improves the system’s performance and control accuracy.By using the best input and output MFs protocol,the energy and financial efficiency of every SISO FS can be improved with very little tuning of MFs.The proposed fuzzy system performed far better than other modern days approaches available in the literature.展开更多
In this short contribution, a reciprocity relation between mass constituents of the universe was explained governed by Hardy’s maximum entanglement probability of φ5 = 0.09017. While well explainable through a set-t...In this short contribution, a reciprocity relation between mass constituents of the universe was explained governed by Hardy’s maximum entanglement probability of φ5 = 0.09017. While well explainable through a set-theoretical argumentation, the relation may also be a consequence of a coupling factor attributed to the normed dimensions of the universe. Also, very simple expressions for the mass amounts were obtained, when replacing the Golden Mean φ by the Archimedes’ constant π. A brief statement was devoted to the similarity between the E-Infinity Theory of El Naschie and the Information Relativity Theory of Suleiman. In addition, superconductivity was also linked with Hardy’s entanglement probability.展开更多
As teachers of EFL (English as a Foreign Language) in the Kingdom of Saudi Arabia, we are sometimes flabbergasted by the errors that the/earners make in their English scripts. Apparently, there was no pattern to the...As teachers of EFL (English as a Foreign Language) in the Kingdom of Saudi Arabia, we are sometimes flabbergasted by the errors that the/earners make in their English scripts. Apparently, there was no pattern to these errors. However, when the researcher observed the frequency of similar error over a few years of her experience as an EFL faculty for Saudi learners, the theory of Lexical Relations appeared to offer an answer. Therein also lies the genesis of the current study. In a positive development, the study did bring to light certain factors that directly played a role in the Saudi EFL learners' English errors. These have been presented in this paper with the hope that with the diagnosis in hand, it will be easier for the EFL teachers to find a solution to the dearth of English proficiency among the Saudi EFL learners.展开更多
It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this...It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this paper we propose a new inefficiency of the least squares estimator with the measure of generalized variance and obtain its bound.展开更多
Some fundamental physical quantities need an alternative description. We derive the word average value of interaction coupling constant α<sub>s</sub>(m<sub>z</sub>) from the observed maximum g...Some fundamental physical quantities need an alternative description. We derive the word average value of interaction coupling constant α<sub>s</sub>(m<sub>z</sub>) from the observed maximum galactic rotation velocity by the simple relation , where is the velocity, at which the difference between galactic rotation velocity and Thomas precession is equal, and α is Sommerfeld’s constant. The result is in excellent agreement with the value of α<sub>s</sub> = 0.1170 ± 0.0019, recently measured and verified via QCE analysis by CERN researchers. One can formulate a reciprocity relation, connecting α<sub>s</sub> with the circle constant: . It is the merit of Preston Guynn to derive the Milky Way maximum value of the galactic rotation velocity β<sub>g</sub>, pointing to its “extremely important role in all physics”. The mass (energy) constituents of the Universe follow a golden mean hierarchy and can simply be related to the maximum of Guynn’s difference velocity respectively to α<sub>s</sub>(m<sub>z</sub>), therewith excellently confirming Bouchet’s WMAP data analysis. We conclude once more that the golden mean concept is the leading one of nature.展开更多
When you mention lexicology,absolutely it is a branch of linguistics,inquiring into the origins and meanings of words.The lexicologist Mc Carthy(1990)have given us his opinion about it.He said,grammar is important,and...When you mention lexicology,absolutely it is a branch of linguistics,inquiring into the origins and meanings of words.The lexicologist Mc Carthy(1990)have given us his opinion about it.He said,grammar is important,and it indeed plays a vital rolein English study,but that is not all.In fact,tar from this.From this we can see,vocabulary and the study and learning of vocabularytake an outstanding place in the study of language,it will improve his skills of using reference books and raise his problem-solvingability and efficiency of individual study.And it will make you much more receptive and productive in language processing and lan-guage production.Knowledge of English Lexicology can offer a great help to the work of the teachers of English.Armed with thisknowledge,they can better control the teaching materials,especially the concerning words.They can also select and organize mate-rials to teach in a more effective way.What is more,they can make use of the different sense relations to group vocabulary,inter-pret words and explain meanings to the students;At last,their teaching will prove better if they have the knowledge of dictionaries.In my thesis,I will talk about how to deal with new words in material.展开更多
A modified Swift type flow stress—strain relation was presented in order to describe the uniaxial tension test curve reasonably. The FLD-strain (forming limit diagram made up of limit strain) of 5754O aluminum allo...A modified Swift type flow stress—strain relation was presented in order to describe the uniaxial tension test curve reasonably. The FLD-strain (forming limit diagram made up of limit strain) of 5754O aluminum alloy sheet was calculated based on the two flow stress—strain relations using Yld2000-2d yield function. By comparing the theoretical and experimental results, it is found that the calculated FLD-strain based on the modified Swift flow stress—strain relation can reasonably describe the experimental results. However, though the common Voce flow stress—strain relation can describe the deformation behavior during homogenous deformation phase accurately, the FLD-strain calculated based on it is obviously lower than the experimental result. It is concluded that the higher the hardening rate of sheet metal is, the higher the forming limit is. A method for determining the reasonable flow stress—strain relation is recommended for describing the material behavior during inhomogenous phase and the forming limit of sheet metal.展开更多
An orthorhombic polycrystal is an orthorhombic aggregate of tiny crystallites. In this paper, we study the effect of the crystalline mean shape on the constitutive relation of the orthorhombic polycrystal. The crystal...An orthorhombic polycrystal is an orthorhombic aggregate of tiny crystallites. In this paper, we study the effect of the crystalline mean shape on the constitutive relation of the orthorhombic polycrystal. The crystalline mean shape and the crystalline orientation arrangement are described by the crystalline shape function (CSF) and the orientation distribution function (ODF), respectively. The CSF and the ODF are expanded as an infinite series in terms of the Wigner D-functions. The expanded coefficients of the CSF and the ODF are called the shape coefficients s^lm0 and the texture coefficients c^lmn respectively. Assuming that Ceff in the constitutive relation depends on the shape coefficients s^lm0 and the texture coefficients c^lmn by the principle of material frame-indifference we derive an analytical expression for C^eff up to terms linear in s^lmo and c^lmn and the expression would be applicable to the polycrystal whose texture is weak and whose crystalline mean shape has weak anisotropy. C^cff contains six unspecified material constants (λ, μ, c, s1, s2, s3), five shape coefficients (s^2 00, s^2 20, s^4 00, s^4 20, s^4 40), and three texture coefficients (c^4 99,c^4 20, c^4 40), The results based on the perturbation approach are used to determine the five material constants approximately. We also find that the shape coefficients 2 and a s^2mo and s^4m0 are all zero if the crystalline mean shape is a cuboid. Some examples are given to compare our computational results.展开更多
Light is crucial to the uniform production of high-quality fruit since it is the driving force for leaf photosynthesis and hence overall plant nutrition.The objective of this study was to evaluate the relationship bet...Light is crucial to the uniform production of high-quality fruit since it is the driving force for leaf photosynthesis and hence overall plant nutrition.The objective of this study was to evaluate the relationship between the distribution of relative light intensity in the peach tree(Prunus persica)canopy and the yield and texture of peach fruits.The canopy of 7-year-old‘Qiuyan’was divided into cubical volumes and the relative light intensity distribution was measured for each cube,along with yield distribution and fruit textural properties at different growing times.The relative light intensity decreased gradually from outside to inside the canopy and from top to bottom.The yield distribution and the relative light intensity were clearly correlated.The percentage of the canopy receiving<30%relative light intensity was 49.07%in May,56.02%in June,and 58.95%in July,whereas the percentage receiving>80%relative light intensity was 32.72%,17.28%,and 10.96%,respectively.Consistent with this,peaches were found in the upper and middle portions of the canopy,within 1.5-3.0 m of the top.The regression equation showed that fruit texture index correlated significantly with relative light intensity.Relative light intensity is the main factor affecting peach yield and texture and must be above 41.83%for good peach quality.Orchardists should carefully plan summer pruning strategies to adjust the number and spatial distribution of branches accordingly.展开更多
The essence of prose lies in expressing meaning and feeling of the prose, describing things and reasoning in real,plain and direct way, which is referred as its natural character. What the prose requires is to strive ...The essence of prose lies in expressing meaning and feeling of the prose, describing things and reasoning in real,plain and direct way, which is referred as its natural character. What the prose requires is to strive to make equivalence in the meaning, forms, taste, style and other aspects with the original text. What the prose express is not only the thematic meaning but also the stylistic meaning, in other words, the meaning that was contained in the content and forms. Hilaire Belloc, a famous prolific writer and historian, have formulated the six principles in translation of prose, in which he believes that the essence of translating is the resurrection of an alien thing in a native body.展开更多
Based on the theoretical presentations of a contemporary development in grammar instruction named focus on form as well as the analysis of the need for such grammar instructional approach utilized in Chinese college c...Based on the theoretical presentations of a contemporary development in grammar instruction named focus on form as well as the analysis of the need for such grammar instructional approach utilized in Chinese college classrooms, this paper attempts to make a tentative proposal to apply focus on form approach to grammar teaching in colleges through recommending practicable instructional reflections.展开更多
An important question that arises is which surfaces in three-space admit a mean curvature preserving isometry which is not an isometry of the whole space. This leads to a class of surface known as a Bonnet surface in ...An important question that arises is which surfaces in three-space admit a mean curvature preserving isometry which is not an isometry of the whole space. This leads to a class of surface known as a Bonnet surface in which the number of noncongruent immersions is two or infinity. The intention here is to present a proof of a theorem using an approach which is based on differential forms and moving frames and states that helicoidal surfaces necessarily fall into the class of Bonnet surfaces. Some other results are developed in the same manner.展开更多
We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubes...We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubescens, the intemode number was assigned from base to tip and the length for each internode was directly measured. The result indicated that the intemode length should be cumulated from base to tip, and then the cumulated internode length should be relativized by the total culm length. It was inappropriate to relativize the internode length by the maximum intenode length. In addition, the relationship between the relative internode number (the intemode number relativized by the total number of intemodes) and the relative cumulated internode length should be described not by a power function but by a sigmoid function such as the third-order function. The determined function enabled us to estimate the actual internode length, with the root mean squared error being 4 cm. In conclusion, the mathematical expression presented here, i.e., the relativization of the cumulated internode length by the total culm length and the application of the sigmoid function, will be useful in describing the relationship between internode number and internode length for P. pubescens.展开更多
In this work, we derive the nuclear form factor for the spin-independent collision between the WIMPs and nucleus in terms of the relativistic mean field (RMF) theory. Comparison with the traditional form factors whi...In this work, we derive the nuclear form factor for the spin-independent collision between the WIMPs and nucleus in terms of the relativistic mean field (RMF) theory. Comparison with the traditional form factors which are commonly used in literature is given and it is found that our results are slightly above that of the 2PF model by 4% to 8%, but deviate from the Helm form factor by 15% to 25% for the whole recoil energy spectrum of 0 -100 keV. Moreover, taking Xe and Ge as examples, we show the dependence of the form Factor on the recoil energy.展开更多
In this paper,we study the proximal relation,regionally proximal relation and Banach proximal relation of a topological dynamical system for amenable group actions.A useful tool is the support of a topological dynamic...In this paper,we study the proximal relation,regionally proximal relation and Banach proximal relation of a topological dynamical system for amenable group actions.A useful tool is the support of a topological dynamical system which is used to study the structure of the Banach proximal relation,and we prove that above three relations all coincide on a Banach mean equicontinuous system generated by an amenable group action.展开更多
文摘We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.
文摘This thesis mainly analyzes the content and form of Robert Morgan's postmodern poem"Mountain Graveyard". With New Criticism's method of close reading, it firstly explores the possible interpretations of the poem's content. Then it analyzes the post-modernity due to the poem's form, pointing out that with the unique form breaking traditional poetry's conventions, and the upspring of multiple meanings from the content, this poem presents brilliantly the postmodern spirit, which rejects definite centers and embraces various diversity of meaning.
基金supported by Major Special Projects of Science and Technology in Fujian Province,(Grant No.2020HZ03018)Natural Science Foundation of Fujian Province(Grant No.2020J01873).
文摘In gas metal arc welding(GMAW)process,the short-circuit transition was the most typical transition observed in molten metal droplets.This paper used orthogonal tests to explore the coupling effect law of welding process parameters on the quality of weld forming under short-circuit transition,the design of 3 factors and 3 levels of a total of 9 groups of orthogonal tests,welding current,welding voltage,welding speed as input parameters:effective area ratio,humps,actual linear power density,aspect ratio,Vickers hardness as output paramet-ers(response targets).Using range analysis and trend charts,we can visually depict the relationship between input parameters and a single output parameter,ultimately determining the optimal process parameters that impact the single output index.Then combined with gray the-ory to transform the three response targets into a single gray relational grade(GRG)for analysis,the optimal combination of the weld mor-phology parameters as follows:welding current 100 A,welding voltage 25 V,welding speed 30 cm/min.Finally,validation experiments were conducted,and the results showed that the error between the gray relational grade and the predicted value was 2.74%.It was observed that the effective area ratio of the response target significantly improved,validating the reliability of the orthogonal gray relational method.
文摘Whether to adopt the meaning-oriented or form-oriented approach in EFL teaching has been in hot academic debate in the past decades. This paper investigates the literature contribution on these two methods, attempts an integration of the two,and introduces a teaching experiment of EFL reading and writing at China Agricultural University.
文摘For fuzzy systems to be implemented effectively,the fuzzy membership function(MF)is essential.A fuzzy system(FS)that implements precise input and output MFs is presented to enhance the performance and accuracy of single-input single-output(SISO)FSs and introduce the most applicable input and output MFs protocol to linearize the fuzzy system’s output.Utilizing a variety of non-linear techniques,a SISO FS is simulated.The results of FS experiments conducted in comparable conditions are then compared.The simulated results and the results of the experimental setup agree fairly well.The findings of the suggested model demonstrate that the relative error is abated to a sufficient range(≤±10%)and that the mean absolute percentage error(MPAE)is reduced by around 66.2%.The proposed strategy to reduceMAPE using an FS improves the system’s performance and control accuracy.By using the best input and output MFs protocol,the energy and financial efficiency of every SISO FS can be improved with very little tuning of MFs.The proposed fuzzy system performed far better than other modern days approaches available in the literature.
文摘In this short contribution, a reciprocity relation between mass constituents of the universe was explained governed by Hardy’s maximum entanglement probability of φ5 = 0.09017. While well explainable through a set-theoretical argumentation, the relation may also be a consequence of a coupling factor attributed to the normed dimensions of the universe. Also, very simple expressions for the mass amounts were obtained, when replacing the Golden Mean φ by the Archimedes’ constant π. A brief statement was devoted to the similarity between the E-Infinity Theory of El Naschie and the Information Relativity Theory of Suleiman. In addition, superconductivity was also linked with Hardy’s entanglement probability.
文摘As teachers of EFL (English as a Foreign Language) in the Kingdom of Saudi Arabia, we are sometimes flabbergasted by the errors that the/earners make in their English scripts. Apparently, there was no pattern to these errors. However, when the researcher observed the frequency of similar error over a few years of her experience as an EFL faculty for Saudi learners, the theory of Lexical Relations appeared to offer an answer. Therein also lies the genesis of the current study. In a positive development, the study did bring to light certain factors that directly played a role in the Saudi EFL learners' English errors. These have been presented in this paper with the hope that with the diagnosis in hand, it will be easier for the EFL teachers to find a solution to the dearth of English proficiency among the Saudi EFL learners.
文摘It was suggested by Pantanen that the mean squared error may be used to measure the inefficiency of the least squares estimator. Styan[2] and Rao[3] et al. discussed this inefficiency and it's bound later. In this paper we propose a new inefficiency of the least squares estimator with the measure of generalized variance and obtain its bound.
文摘Some fundamental physical quantities need an alternative description. We derive the word average value of interaction coupling constant α<sub>s</sub>(m<sub>z</sub>) from the observed maximum galactic rotation velocity by the simple relation , where is the velocity, at which the difference between galactic rotation velocity and Thomas precession is equal, and α is Sommerfeld’s constant. The result is in excellent agreement with the value of α<sub>s</sub> = 0.1170 ± 0.0019, recently measured and verified via QCE analysis by CERN researchers. One can formulate a reciprocity relation, connecting α<sub>s</sub> with the circle constant: . It is the merit of Preston Guynn to derive the Milky Way maximum value of the galactic rotation velocity β<sub>g</sub>, pointing to its “extremely important role in all physics”. The mass (energy) constituents of the Universe follow a golden mean hierarchy and can simply be related to the maximum of Guynn’s difference velocity respectively to α<sub>s</sub>(m<sub>z</sub>), therewith excellently confirming Bouchet’s WMAP data analysis. We conclude once more that the golden mean concept is the leading one of nature.
文摘When you mention lexicology,absolutely it is a branch of linguistics,inquiring into the origins and meanings of words.The lexicologist Mc Carthy(1990)have given us his opinion about it.He said,grammar is important,and it indeed plays a vital rolein English study,but that is not all.In fact,tar from this.From this we can see,vocabulary and the study and learning of vocabularytake an outstanding place in the study of language,it will improve his skills of using reference books and raise his problem-solvingability and efficiency of individual study.And it will make you much more receptive and productive in language processing and lan-guage production.Knowledge of English Lexicology can offer a great help to the work of the teachers of English.Armed with thisknowledge,they can better control the teaching materials,especially the concerning words.They can also select and organize mate-rials to teach in a more effective way.What is more,they can make use of the different sense relations to group vocabulary,inter-pret words and explain meanings to the students;At last,their teaching will prove better if they have the knowledge of dictionaries.In my thesis,I will talk about how to deal with new words in material.
基金Project(51005010)supported by the National Natural Science Foundation of China
文摘A modified Swift type flow stress—strain relation was presented in order to describe the uniaxial tension test curve reasonably. The FLD-strain (forming limit diagram made up of limit strain) of 5754O aluminum alloy sheet was calculated based on the two flow stress—strain relations using Yld2000-2d yield function. By comparing the theoretical and experimental results, it is found that the calculated FLD-strain based on the modified Swift flow stress—strain relation can reasonably describe the experimental results. However, though the common Voce flow stress—strain relation can describe the deformation behavior during homogenous deformation phase accurately, the FLD-strain calculated based on it is obviously lower than the experimental result. It is concluded that the higher the hardening rate of sheet metal is, the higher the forming limit is. A method for determining the reasonable flow stress—strain relation is recommended for describing the material behavior during inhomogenous phase and the forming limit of sheet metal.
基金The project supported by the National Natural Science Foundation of China(10562004)the Oversea Returning Grant of China.
文摘An orthorhombic polycrystal is an orthorhombic aggregate of tiny crystallites. In this paper, we study the effect of the crystalline mean shape on the constitutive relation of the orthorhombic polycrystal. The crystalline mean shape and the crystalline orientation arrangement are described by the crystalline shape function (CSF) and the orientation distribution function (ODF), respectively. The CSF and the ODF are expanded as an infinite series in terms of the Wigner D-functions. The expanded coefficients of the CSF and the ODF are called the shape coefficients s^lm0 and the texture coefficients c^lmn respectively. Assuming that Ceff in the constitutive relation depends on the shape coefficients s^lm0 and the texture coefficients c^lmn by the principle of material frame-indifference we derive an analytical expression for C^eff up to terms linear in s^lmo and c^lmn and the expression would be applicable to the polycrystal whose texture is weak and whose crystalline mean shape has weak anisotropy. C^cff contains six unspecified material constants (λ, μ, c, s1, s2, s3), five shape coefficients (s^2 00, s^2 20, s^4 00, s^4 20, s^4 40), and three texture coefficients (c^4 99,c^4 20, c^4 40), The results based on the perturbation approach are used to determine the five material constants approximately. We also find that the shape coefficients 2 and a s^2mo and s^4m0 are all zero if the crystalline mean shape is a cuboid. Some examples are given to compare our computational results.
基金China Agriculture Research System(Nos.2019-3-5-1-02,2019-3-4-4,F18R06001-1)China Agriculture Research System of MOF and MARA(No.CARS-30-Z-02)Hebei Province Key Research and Development Project(No.17226341).
文摘Light is crucial to the uniform production of high-quality fruit since it is the driving force for leaf photosynthesis and hence overall plant nutrition.The objective of this study was to evaluate the relationship between the distribution of relative light intensity in the peach tree(Prunus persica)canopy and the yield and texture of peach fruits.The canopy of 7-year-old‘Qiuyan’was divided into cubical volumes and the relative light intensity distribution was measured for each cube,along with yield distribution and fruit textural properties at different growing times.The relative light intensity decreased gradually from outside to inside the canopy and from top to bottom.The yield distribution and the relative light intensity were clearly correlated.The percentage of the canopy receiving<30%relative light intensity was 49.07%in May,56.02%in June,and 58.95%in July,whereas the percentage receiving>80%relative light intensity was 32.72%,17.28%,and 10.96%,respectively.Consistent with this,peaches were found in the upper and middle portions of the canopy,within 1.5-3.0 m of the top.The regression equation showed that fruit texture index correlated significantly with relative light intensity.Relative light intensity is the main factor affecting peach yield and texture and must be above 41.83%for good peach quality.Orchardists should carefully plan summer pruning strategies to adjust the number and spatial distribution of branches accordingly.
文摘The essence of prose lies in expressing meaning and feeling of the prose, describing things and reasoning in real,plain and direct way, which is referred as its natural character. What the prose requires is to strive to make equivalence in the meaning, forms, taste, style and other aspects with the original text. What the prose express is not only the thematic meaning but also the stylistic meaning, in other words, the meaning that was contained in the content and forms. Hilaire Belloc, a famous prolific writer and historian, have formulated the six principles in translation of prose, in which he believes that the essence of translating is the resurrection of an alien thing in a native body.
文摘Based on the theoretical presentations of a contemporary development in grammar instruction named focus on form as well as the analysis of the need for such grammar instructional approach utilized in Chinese college classrooms, this paper attempts to make a tentative proposal to apply focus on form approach to grammar teaching in colleges through recommending practicable instructional reflections.
文摘An important question that arises is which surfaces in three-space admit a mean curvature preserving isometry which is not an isometry of the whole space. This leads to a class of surface known as a Bonnet surface in which the number of noncongruent immersions is two or infinity. The intention here is to present a proof of a theorem using an approach which is based on differential forms and moving frames and states that helicoidal surfaces necessarily fall into the class of Bonnet surfaces. Some other results are developed in the same manner.
基金supported in part by the fiscal 2010 special grant from the president of the Prefectural University of Kumamoto
文摘We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubescens, the intemode number was assigned from base to tip and the length for each internode was directly measured. The result indicated that the intemode length should be cumulated from base to tip, and then the cumulated internode length should be relativized by the total culm length. It was inappropriate to relativize the internode length by the maximum intenode length. In addition, the relationship between the relative internode number (the intemode number relativized by the total number of intemodes) and the relative cumulated internode length should be described not by a power function but by a sigmoid function such as the third-order function. The determined function enabled us to estimate the actual internode length, with the root mean squared error being 4 cm. In conclusion, the mathematical expression presented here, i.e., the relativization of the cumulated internode length by the total culm length and the application of the sigmoid function, will be useful in describing the relationship between internode number and internode length for P. pubescens.
基金Supported by the National Natural Science Foundation of China under Grant No.11075079
文摘In this work, we derive the nuclear form factor for the spin-independent collision between the WIMPs and nucleus in terms of the relativistic mean field (RMF) theory. Comparison with the traditional form factors which are commonly used in literature is given and it is found that our results are slightly above that of the 2PF model by 4% to 8%, but deviate from the Helm form factor by 15% to 25% for the whole recoil energy spectrum of 0 -100 keV. Moreover, taking Xe and Ge as examples, we show the dependence of the form Factor on the recoil energy.
基金supported by NSF of China(11671057)NSF of Chongqing(cstc2020jcyj-msxm X0694)the Fundamental Research Funds for the Central Universities(2018CDQYST0023)。
文摘In this paper,we study the proximal relation,regionally proximal relation and Banach proximal relation of a topological dynamical system for amenable group actions.A useful tool is the support of a topological dynamical system which is used to study the structure of the Banach proximal relation,and we prove that above three relations all coincide on a Banach mean equicontinuous system generated by an amenable group action.