|
|
Springer新书推介:From Multiscale Modeling to Meso-Science |
|
|
A Chemical Engineering Perspective
Principles, Modeling, Simulation, and Application
Li, J., Ge, W., Wang, W., Yang, N., Liu, X., Wang, L., He, X., Wang, X., Wang, J., Kwauk, M.
2013, XXVI, 484 p. 255 illus., 152 in color.
|
What is Meso-Science or Mesoscience?
Meso-science ( mesoscience ) is an emerging science for all meso-scales existing between elemental particles and the observable universe.
A 'science' requires its own common principles and physical and mathematical arguments for different problems. Although meso-science is an emerging field — meaning an exact definition may be premature — it is thought that the following preliminary description of its scope will help to attract or trigger interest from various disciplines and to orient the direction of their efforts to this field [1]:
• Common phenomena: Many meso-scales exist in the spectrum of physical science and engineering [2] which is only one of many branches of the complex world. In fact, meso-scale issues exist everywhere not only in nature but also in society. The universality and importance of meso-scale problems as well as their relationship with complexity and diversity in our world mean that exploring a common and interdisciplinary science — meso-science— to describe all meso-scale phenomena deserves the combined effort of different fields.
• Common challenge: The importance of meso-science is its potential universality for all meso-scale phenomena existing between elemental particles and the observable universe. Meso-scale phenomena and interactions are a common challenge in the entire spectrum of science and engineering [1, 2]. Most difficulties, currently preventing the development of various individual disciplines and their integration, occur at various meso-scales, however, have not been tackled with a unified way. Variety of methods and approaches are currently used in different engineering fields and scientific disciplines to deal with the complexity and diversity occurring at meso-scales, such as coarse grained methods and constitutive equations, without extracting common natures and identifying common principles. If a common principle for all meso-scales can be really confirmed, solutions to these challenges may be significantly facilitated.
• Common principles and arguments: Common principles maybe exist for all meso-scale problems, that is, “compromise in competition between dominant mechanisms with self-coordination of each” in physics and “multi-objective variational formulation” in mathematics [1, 2]. Such universalities in physics and mathematics have been analyzed for the three levels of chemical engineering and can be potentially extended to all meso-scales [3, 4, 5]. In fact, as long as two or more dominant mechanisms are in action in a system, as is usually encountered in our life, research and activities, they must compromise with each other in their competition (usually showing extremum behavior) when none of these mechanisms is able to dominate the others. As a result, each mechanism has to self-coordinate to have collective actions of all corresponding elements related to it (i.e. self-organization) to reach a meso-state. This state features alternate dominance of the different mechanisms with respect to changes in both space and time [6]. It can be predicted that self-organizations all occur at meso-scales, and driven by compromise in competition. Such complex interactions between dominant mechanisms and external influences lead to complexity, diversity and dissipation. This principle could be universal, and therefore, meso-science may provide a way to better understand relationships between concepts such as complexity, diversity, self-assembly, self-organization, linearity and non-linearity, chaos, order and disorder, dissipation and conservation, compromise, competition and coordination, and other terms. Meso-science may act as a bridge between reductionism to understand details at ‘‘elemental’’ or ‘‘small’’ scales and holism to interpret global behavior at ‘‘system’’ or ‘‘large’’ scales; that is, it is a science between small and large scales. Here, ‘‘small’’ and ‘‘large’’ are both relative concepts, spanning the range of size between elemental particles and the universe, giving meso-science an interdisciplinary nature.
• Common angle to view old problems: Meso-science is not something new for all disciplines; instead it involves a different, new angle to view systems where meso-scales and compromise at different levels are focused on. That is, problems to be studied by meso-science could be the same as investigated traditionally, but the philosophy at the origin and principles observed would differ. The focus would be on the physics of compromise, competition and coordination in systems and their formulations. Meso-science implies there are some underlying principles that can unify different disciplines, and all disciplines may be involved in contributing available disciplinarily specific knowledge at corresponding levels to revealing common principles for meso-scales at all levels. A small change in the angle to view old problems could lead to a big progress in sloving them.
• Practice at meso-scales of different levels: It is critical to recognize that mesoscale issues may be correctly analyzed only when ‘‘levels’’ are reasonably identified. It is evident that the common principle of compromise cannot be extracted without distinguishing specified levels and scales in each level. It is thought that none of the sciences was an exception, or at least, excludes the principle of compromise [4], manifesting that different meso-scales are governed by the same underlying principle.
What discussed above imply some important natures required for being a science — meso-science, that is, common principles and common physical and mathematical arguments, from which a preliminary definition of meso-science could be ‘the science of the universality of meso-scale phenomena’, or ‘the science of compromise, competition and coordination’, or in short, ‘the science of compromise’, which involves searching for the common physical principles and their mathematical formulation. Of course, this does not refer to concrete formulation, but to a general framework to describe the complexity and diversity of systems. That is, customized formulations are needed for different meso-scale problems because of the disparity of dominant mechanisms involved in them. However, these mechanisms all follow the identical principle of compromise and the same framework of multi-objective variational formulation.
The establishment of meso-science will hopefully cause a substantial upgrade of the knowledge base of science and technology. The following objectives are the initial focus of meso-science:
1. Understanding meso-scales in different fields to extract common principles of compromise in the competition between dominant mechanisms. This may be a starting point for meso-science, and can easily involve all areas;
2. Revealing the detailed processes of compromise in competition between dominant mechanisms and self-coordination of each mechanism in jointly stabilizing various meso-scale phenomena and generating complexity and diversity. This will show the potential of meso-science to solve complicated problems from a new angle;
3. Formulating the extremum tendencies of dominant mechanisms. This should be done even following traditional approaches, and may also lead to new knowledge in apparently well established disciplines;
4. Understanding and/or modifying the formulation of the multi-objective variational problem to establish a unified mathematical tool to solve it. This is a challenge even for mathematicians, but could be simplified in many cases. Simplified solutions to many problems have worked well while waiting for a general mathematical tool to be established;
5. Determining an effective way to realize structural consistency between problem, model, software and hardware, giving powerful computational capability for meso-scale problems [7]. Contribution from computer scientists is required to realize this objective. Experiment technologies are to be developed to observe meso-scale phenomena which usually call for high resolutions both in space and in time;
6. Correlating two or more meso-scales at different levels, or hopefully even over a whole spectrum, will enable two or more disciplines to be integrated or unified. This may be a way to understand the relationship between microscopic and macroscopic phenomena, as expected by complexity science.
If meso-science as discussed here becomes a reality, it will facilitate the seamless correlation between different disciplines, which will provide great benefits. With increasing knowledge on meso-scale phenomena, its definition will be more and more accurate. Currently, above descriptions will be helpful to stimulate and to trigger interests and attention in this emerging science!
References:
1. Li J et al. (2013) From multiscale modeling to meso-science : A chemical engineering perspective, Springer, 2013
2. Li J, Huang W, Edwards P, Kwauk M, Houghton J, Slocombe D (2013) On universality of mesoscience: science of ‘the in-between’. http://arxiv.org/abs/1302.5861
3. Ge et al. (2011) Mesoscale oriented simulation towards virtual process engineering (VPE)—the EMMS paradigm. Chem Eng Sci 66(19):4426–4458
4.Li J, Ge W, Kwauk M (2009) Meso-scale phenomena from compromise—a common challenge, not only for chemical engineering. Arxiv preprint arXiv:0912.5407
5. Li J, Ge W, Wang W, Yang N (2010) Focusing on the meso-scales of multiscale phenomena-In search for a new paradigm in chemical engineering. Particuology 8(6):634–639
6. Li, J., Zhang, J., Ge, W. & Liu, X (2004). Multi-scale methodology for complex systems. Chem. Eng. Sci. 59, 1687-1700
7. Chen F, Ge W, Guo L, He X, Li B, Li J, Li X, Wang X, Yuan X (2009) Multi-scale HPC system for multi-scale discrete simulation—development and application of a supercomputer with 1 Petaflops peak performance in single precision. Particuology 7:332–335