The horror of Romantic medicine and its befitting demise

Romantic medicine in continental Europe was practiced from the 1790s until the mid-nineteenth century as part of the greater movement of Romanticism.It reacted to an ongoing foundational crisis in medicine when radically new approaches to healing were essential.Especially in German-speaking countries,Romantic medicine resulted fom anti-science sentiments to Enlightenment ideas favoring scientific progress based 0 materialist and reductionist assumptions.For the Romanticists,these were troublesome fo the individual,nature and the future.However,without understanding disease and by rejecting both the scientific method and mysticism,attention tumed to post-Kantian idealism and Naturphilosophie What distinguished Romantic medicine from existing humoralism was a passion for comprehending the exceptional attribute of life itself,implicitly from which a new medicine could ascend.However,better healthcare was not(achieved).Although anatomy and physiology had made rapid strides,these did not directly benefit patients.News of successive developments in medicine did not appear to circulate to healers.Meantime,since the eighteenth century,recognition of the seat of disease had progressed from the whole-body(humor theory),to organs(Morgagni),to tissues(Bichat)。and eventually to cells(Virchow)where hypotheses could be tested.Possible reasons for the downfall of Romantic medicine include socio-political pressures that demanded better healthcare,Comte's positivism,the successes of cell and germ theories of disease,Virchow's Cellularpathologie,diminishing professional dogmatism and improved medical communications.

Recent theoretical progress in the development of perovskite photovoltaic materials

Since the seminal work by Kojima et al. in 2009, solar cells based on hybrid organic-inorganic perovskites have attracted considerable attention and experienced an exponential growth, with photovoltaic efficiencies as of today reaching above 22%. Despite such an impressive development, some key scientific issues of these materials, including the presence of toxic lead, the poor long-term device stability under heat and humidity conditions, and the anomalous hysteresis of the current-voltage curves shown by various solar cell devices, still remain unsolved and constitute an important focus of experimental and theoretical researchers throughout the world. Density functional theory calculations have been successfully applied to exploring structural and electronic properties of semiconductors, complementing the experimental results in search and discovery of novel functional materials. In this review, we summarize the current progress in perovskite photovoltaic materials from a theoretical perspective. We discuss design of lead-free perovskite materials, humidity-induced degradation mechanisms and possible origins for the observed solar cell hysteresis, and assess future research directions for advanced perovskite solar cells based on computational materials design and theoretical understanding of intrinsic properties.

Thermionic emission theory and diffusion theory applied to CdTe PV devices

In this work, a comprehensive model that takes the phenomenon of carrier thermionic-emission within the frame work of a diffusion theory of current conducting into account in the type Ⅱ hetero-junction Cd Te solar cell is developed. According to this model, it is found that the total current flowing through the Cd Te solar cell is limited by the thermionic process for very thin quasi-neutral regions and limited by the diffusion process for the reverse case. In future research of the Cd Te solar cell, such an approach may enable the determination of the boundary conditions for all doping profiles and computation of the conversion efficiency, etc.