Tai Chi, a Chinese martial art developed based on the laws of nature, emphasises how 'to conquer the unyielding with the yielding.' The recent observation of star formation shows that stars result from the interaction between gravity, turbulence and magnetic fields. This interaction again follows the natural rules that inspired Tai Chi. For example, if self-gravity is the force that dominates, the molecular cloud will collapse isotropically, which compresses magnetic field lines. The density of the yielding field lines increases until magnetic pressure reaches the critical value to support the cloud against the gravitational force in directions perpendicular to the field lines (Lorentz force). Then gravity gives way to Lorentz force, accumulating gas only along the field lines till the gas density achieves the critical value to again compress the field lines. The Tai Chi goes on in a self similar way.

In altering chapers, the novel tells the stories of Sunamei, a young woman from a rural matriarchal community, and Lian Rui, a self-absorbed man who is also weary witness to the Cultural Revolution. Through his two protagonists, the author addresses themes of the repression and freedon of sexuality, the brutality of modernity, and the fluidity of gender roles as the novel moves hypnotically and inevitably toward a collision between two worlds.

Nitrate is one of the major sources of nitrogen taken up by plants. A large proportion of the nitrate acquired by plants is actively transported through nitrate transporters (NRT). To cope with low and high nitrate concentration in the soil, plants have developed high-affinity and low-affinity nitrate uptake systems, respectively. Genes of the NRT1 family are mainly low affinity nitrate transporters, and genes of the NRT2 family are high affinity transporters, whose functioning requires the participation of NRT3. Up to now, the molecular features and the regulation of nitrate transporters have been studied mostly in the model plant Arabidopsis thaliana. The molecular characterization of all NRT family genes has not yet been conducted in poplar, which is a model plant for genetic analysis in tree species. Earlier studies on poplar suggested that the response to N fertilization of poplar growth and wood properties were species-specific traits. We hypothesized that these traits also how intra-specific variation in response to N fertilization, because large differences in plant productivity were found among poplar genotypes. To investigate the role of NRT genes in poplar growth, four questions will be addressed in the present thesis.

This book discusses topics related to power electronics, especially electromagnetic transient analysis and control of high-power electronics conversion. It focuses on the re-evaluation of power electronics, transient analysis and modeling, device-based system-safe operating area, and energy balance-based control methods, and presenting, for the first time, numerous experimental results for the transient process of various real-world converters. The book systematically presents both theoretical analysis and practical applications. The first chapter discusses the structure and attributes of power electronics systems, highlighting the analysis and synthesis, while the second chapter explores the transient process and modeling for power electronics systems. The transient features of power devices at switching-on/off, transient conversion circuit with stray parameters and device-based system-safe operating area are described in the subsequent three chapters. The book also examinesthe measurement of transient processes, electromagnetic pulses and their series, as well as high-performance, closed-loop control, and expounds the basic principles and method of the energy-balanced control strategy. Lastly, it introduces the applications of transient analysis of typical power electronics systems. The book is valuable as a textbook for college students, and as a reference resource for electrical engineers as well as anyone working in the field of high-power electronics system.

In high power, high voltage electronics systems, a strategy to manage short timescale energy imbalances is fundamental to the system reliability. Without a theoretical framework, harmful local convergence of energy can affect the dynamic process of transformation, transmission, and storage which create an unreliable system. With an original approach that encourages understanding of both macroscopic and microscopic factors, the authors offer a solution. They demonstrate the essential theory and methodology for the design, modeling and prototyping of modern power electronics converters to create highly effective systems. Current applications such as renewable energy systems and hybrid electric vehicles are discussed in detail by the authors. Key features: offers a logical guide that is widely applicable to power electronics across power supplies, renewable energy systems, and many other areas analyses the short-scale (nano-micro second) transient phenomena and the transient processes in nearly all major timescales, from device switching processes at the nanoscale level, to thermal and mechanical processes at second level explores transient causes and shows how to correct them by changing the control algorithm or peripheral circuit includes two case studies on power electronics in hybrid electric vehicles and renewable energy systems Practitioners in major power electronic companies will benefit from this reference, especially design engineers aiming for optimal system performance. It will also be of value to faculty staff and graduate students specializing in power electronics within academia.