To obtain the form error of micro-structured surfaces robustly and accurately, a form er- ror evaluation method was developed based on the real coded genetic algorithm （RCGA）. The meth- od employed the average squar...To obtain the form error of micro-structured surfaces robustly and accurately, a form er- ror evaluation method was developed based on the real coded genetic algorithm （RCGA）. The meth- od employed the average squared distance as the matching criterion. The point to surface distance was achieved by use of iterative method and the modeling of RCGA for the surface matching was also presented in detail. Parameter selection for RCGA including the crossover rate and population size was discussed. Evaluation results of series simulated surfaces without form error show that this method can achieve the accuracy of root mean square deviation （ Sq ） less than 1 nm and surface pro- file error （ St ） less than 4 nm. Evaluation of the surfaces with different simulated errors illustrates that the proposed method can also robustly obtain the form error with nano-meter precision. The e- valuation of actual measured surfaces further indicates that the proposed method is capable of pre- cisely evaluating micro-structured surfaces.展开更多
A real-time non-uniform rational B-spline （NURBS） surface interpolator is proposed and 5-axis machining method with a flat-end cutter is discussed. With the Taylor expansion and the coordinate transformation, the al...A real-time non-uniform rational B-spline （NURBS） surface interpolator is proposed and 5-axis machining method with a flat-end cutter is discussed. With the Taylor expansion and the coordinate transformation, the algorithms of NURBS interpolation, cutter effective machining radius, cutter offsetting and.inverse kinematics are deduced and implemented, respectively. Different from the conventional free-form surface machining, the proposed interpolator can real-time generate the motion commands of computer numerical control （CNC） machines with CC feedrate, rather than that of CL. An example part surface is demonstrated and the results of simulation show that the proposed method can be applied in actual 5-axis surface machining.展开更多
The comparison of Plato's description of the dialectic in his Republic with Marx's analysis of the value form in The Capital reveals certain common features striking to the reader.How is this possible?The pape...The comparison of Plato's description of the dialectic in his Republic with Marx's analysis of the value form in The Capital reveals certain common features striking to the reader.How is this possible?The paper discusses the grounds of possibility of such a comparison focusing on two levels:firstly,a ground of historical comparability and,secondly,a ground of systematic comparability.Based on these two grounds,the argument highlights two of the common features that can be found in both thinkers,namely the dialectic as a process of complete separation of the intellect from sense perception and as a process that supersedes the form of hypothesis of scientific thinking.展开更多
The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells...The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells (MMSC) and fibroblast colony forming units (CFU-F). The aim of this study was to compare the main characteristics of MMSC and CFU-F derived from the bone marrow of 24 healthy donors. Growth and differentiation parameters, as well as relative expression levels of different genes were analyzed in MMSC and CFU-F. MMSC were cultivated for 5 passages. CFU-F concentration was determined for each bone marrow sample. The data obtained demonstrated the heterogeneity and hierarchical organization of both studied populations of stromal precursor cells-MMSC and CFU-F. These two types of stromal precursor cells turned to be different in most parameters studied. Altogether MMSC seemed to be more immature cells than CFU-F and took up the higher position in hierarchical tree of mesenchymal stem cells. The rate of differentiation and proliferative potential decreased with the donor’s age in both populations MMSC and CFU-F.展开更多
So long as economics is regarded as a science,its mission should be to discover and explain the patterns and phenomena of the world as other scientific disciplines do.Economics is also a theoretical paradigm structure...So long as economics is regarded as a science,its mission should be to discover and explain the patterns and phenomena of the world as other scientific disciplines do.Economics is also a theoretical paradigm structure with which humankind comprehends the real world.As far as its identification and discovery functions are concerned,economics aims to identify and appraise the economic value(value of exchange)of the nonmaterial form of material existence(things)in price or various forms of price.The object of economic research can be expanded to the identification and evaluation of nonmaterial existence.Nonmaterial existence also has its material form(physical carrier)and nonmaterial form.Various applied disciplines have derived from economics to form a system of management science.Though having exceeded certain limitations,such applied disciplines are still subject to the commitments of economic paradigms.Most problems of identification and evaluation facing economics are related to“relational existence,”which takes the forms of intra-domain relationship(and realm state),inter-realm relationship(interactions between various realms),and realms within a realm(multi-tier realm).Change in the commitment of economic paradigms,i.e.the commitment to introduce the realm paradigm into the structure of macro-paradigm aims to overcome the isolation and narrowness of traditional economic paradigms,so that economics becomes tolerant of more important factors and more capable of identifying,evaluating,and explaining the real world.By broadening the horizon of economics,the realm paradigm explores a greater“blue ocean”for the academic research of economics.Only a world perceived as consisting of realm economies with different characteristics is a realistic and sustainable one.Economics must develop a logical system of identification and evaluation commensurate with the realm paradigm to discover and explain the economic patterns and complex phenomena in the real world.A historic task of China’s economics community in academic innovation is to transform paradigms,enhance the identification and discovery functions and explanatory power of economics,and restore the scientific nature of economics.展开更多
基金Supported by the Programme of Introducing Talents of Discipline to Universities (B07018)
文摘To obtain the form error of micro-structured surfaces robustly and accurately, a form er- ror evaluation method was developed based on the real coded genetic algorithm （RCGA）. The meth- od employed the average squared distance as the matching criterion. The point to surface distance was achieved by use of iterative method and the modeling of RCGA for the surface matching was also presented in detail. Parameter selection for RCGA including the crossover rate and population size was discussed. Evaluation results of series simulated surfaces without form error show that this method can achieve the accuracy of root mean square deviation （ Sq ） less than 1 nm and surface pro- file error （ St ） less than 4 nm. Evaluation of the surfaces with different simulated errors illustrates that the proposed method can also robustly obtain the form error with nano-meter precision. The e- valuation of actual measured surfaces further indicates that the proposed method is capable of pre- cisely evaluating micro-structured surfaces.
文摘A real-time non-uniform rational B-spline （NURBS） surface interpolator is proposed and 5-axis machining method with a flat-end cutter is discussed. With the Taylor expansion and the coordinate transformation, the algorithms of NURBS interpolation, cutter effective machining radius, cutter offsetting and.inverse kinematics are deduced and implemented, respectively. Different from the conventional free-form surface machining, the proposed interpolator can real-time generate the motion commands of computer numerical control （CNC） machines with CC feedrate, rather than that of CL. An example part surface is demonstrated and the results of simulation show that the proposed method can be applied in actual 5-axis surface machining.
文摘The comparison of Plato's description of the dialectic in his Republic with Marx's analysis of the value form in The Capital reveals certain common features striking to the reader.How is this possible?The paper discusses the grounds of possibility of such a comparison focusing on two levels:firstly,a ground of historical comparability and,secondly,a ground of systematic comparability.Based on these two grounds,the argument highlights two of the common features that can be found in both thinkers,namely the dialectic as a process of complete separation of the intellect from sense perception and as a process that supersedes the form of hypothesis of scientific thinking.
文摘The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells (MMSC) and fibroblast colony forming units (CFU-F). The aim of this study was to compare the main characteristics of MMSC and CFU-F derived from the bone marrow of 24 healthy donors. Growth and differentiation parameters, as well as relative expression levels of different genes were analyzed in MMSC and CFU-F. MMSC were cultivated for 5 passages. CFU-F concentration was determined for each bone marrow sample. The data obtained demonstrated the heterogeneity and hierarchical organization of both studied populations of stromal precursor cells-MMSC and CFU-F. These two types of stromal precursor cells turned to be different in most parameters studied. Altogether MMSC seemed to be more immature cells than CFU-F and took up the higher position in hierarchical tree of mesenchymal stem cells. The rate of differentiation and proliferative potential decreased with the donor’s age in both populations MMSC and CFU-F.
基金supported by the key research projects of the National Social Sciences Foundation “Accelerating the Creation of the Academic,Discipline,and Discourse Systems in Philosophical and Social Sciences with Chinese Characteristics”(Grant No.18VXK002)CASS Academician Innovation Project “Theoretical Innovations in Economics and Practical Explorations”(Grant No.SKGJCX2019-2020)
文摘So long as economics is regarded as a science,its mission should be to discover and explain the patterns and phenomena of the world as other scientific disciplines do.Economics is also a theoretical paradigm structure with which humankind comprehends the real world.As far as its identification and discovery functions are concerned,economics aims to identify and appraise the economic value(value of exchange)of the nonmaterial form of material existence(things)in price or various forms of price.The object of economic research can be expanded to the identification and evaluation of nonmaterial existence.Nonmaterial existence also has its material form(physical carrier)and nonmaterial form.Various applied disciplines have derived from economics to form a system of management science.Though having exceeded certain limitations,such applied disciplines are still subject to the commitments of economic paradigms.Most problems of identification and evaluation facing economics are related to“relational existence,”which takes the forms of intra-domain relationship(and realm state),inter-realm relationship(interactions between various realms),and realms within a realm(multi-tier realm).Change in the commitment of economic paradigms,i.e.the commitment to introduce the realm paradigm into the structure of macro-paradigm aims to overcome the isolation and narrowness of traditional economic paradigms,so that economics becomes tolerant of more important factors and more capable of identifying,evaluating,and explaining the real world.By broadening the horizon of economics,the realm paradigm explores a greater“blue ocean”for the academic research of economics.Only a world perceived as consisting of realm economies with different characteristics is a realistic and sustainable one.Economics must develop a logical system of identification and evaluation commensurate with the realm paradigm to discover and explain the economic patterns and complex phenomena in the real world.A historic task of China’s economics community in academic innovation is to transform paradigms,enhance the identification and discovery functions and explanatory power of economics,and restore the scientific nature of economics.
