다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

where A represents the magnetic vector potential, is an integral of the hydromagnetic equations. This -integral made it possible to formulate a variational principle for the force-free magnetic fields. The integral expresses the fact that motions cannot transform a given field in an entirely arbitrary different field, if the conductivity of the medium isconsidered infinite. In this paper we shall show that the full set of hydromagnetic equations admit five more integrals, besides the energy integral, if dissipative processes are absent. These integrals, as we shall presently verify, are I2 =fbHvdV, (2)

Proceedings of the National Academy of Sciences

The photovoltaics of organic–inorganic lead halide perovskite materials have shown rapid improvements in solar cell performance, surpassing the top efficiency of semiconductor compounds such as CdTe and CIGS (copper indium gallium selenide) used in solar cells in just about a decade. Perovskite preparation via simple and inexpensive solution processes demonstrates the immense potential of this thin-film solar cell technology to become a low-cost alternative to the presently commercially available photovoltaic technologies. Significant developments in almost all aspects of perovskite solar cells and discoveries of some fascinating properties of such hybrid perovskites have been made recently. This Review describes the fundamentals, recent research progress, present status, and our views on future prospects of perovskite-based photovoltaics, with discussions focused on strategies to improve both intrinsic and extrinsic (environmental) stabilities of high-efficiency devices. Strategies and challenges regardi...

Halide Perovskite Photovoltaics: Background, Status, and Future Prospects

Chemical methods developed over the past two decades enable preparation of colloidal nanocrystals with uniform size and shape. These Brownian objects readily order into superlattices. Recently, the range of accessible inorganic cores and tunable surface chemistries dramatically increased, expanding the set of nanocrystal arrangements experimentally attainable. In this review, we discuss efforts to create next-generation materials via bottom-up organization of nanocrystals with preprogrammed functionality and self-assembly instructions. This process is often driven by both interparticle interactions and the influence of the assembly environment. The introduction provides the reader with a practical overview of nanocrystal synthesis, self-assembly, and superlattice characterization. We then summarize the theory of nanocrystal interactions and examine fundamental principles governing nanocrystal self-assembly from hard and soft particle perspectives borrowed from the comparatively established fields of micro...

Self-Assembly of Colloidal Nanocrystals: From Intricate Structures to Functional Materials

National Natural Science Foundation (China) (Grants 11204205, 60976018, 61274056 and 60990320)

Optical Curtain Effect: Extraordinary Optical Transmission Enhanced by Antireflection

We have designed a patterned OSC based on 2-D arrayed dielectric nanospheres loaded on the indium tin oxide anode with other functional layers conformally embossed in the same profile as the nanosphere array. This design shows an integrated light absorption efficiency of 76.6% in the PSBTBT:PC71BM active layer over the wavelength range from 400 to 900 nm at normal incidence, outperforming the structurally identical planar control cell by 21.6%. Detailed investigations reveal that the excitation of photonic modes including the hybridization of cavity modes and Bloch modes, plasmonic modes, and their mutual coupling are responsible for the observed broadband enhancement in light absorption. Among them, the photonic modes are confirmed to be main contributor at most of the absorption band of PSBTBT:PC71BM, whereas at the absorption band edge of PSBTBT:PC71BM, the plasmonic resonance joins with the photonic resonances, collaboratively producing an enhancement factor as high as 110%. Moreover, the broadband absorption enhancement of our proposal is insensitive to the incident angle, favoring the practical application. This work provides a low cost and efficient route for achieving high-performance OSCs in experiment.

Efficient Light Absorption in Organic Solar Cells Based on Two-Dimensional Arrayed Dielectric Nanospheres

A series of low band gap terpolymers (PBDT–DFBx–DPPy) incorporating various ratios of two acceptor units, difluorobenzene (DFB) and diketopyrrolo[3,4-c]pyrrole (DPP), were synthesized by Pd-catalyzed Stille polymerization. The effects of the DFB and DPP units on UV–Vis absorption, highest occupied molecular orbital (HOMO) energy levels, and terpolymer: PC60BM solar cell performance, especially the short-circuit current (J
 sc), were investigated. The polymer films exhibited broad and intense absorption spectra, covering the spectral range from 300 nm up to 900 nm. The optical properties of these random terpolymers can be easily controlled by tuning the ratio between DFB and DPP; an increase in DFB induced increased absorption between 300 and 550 nm and a lower HOMO energy level. The terpolymer PBDT–DFB50–DPP50 with the percentage of DFB up to 50 % in the bulk heterojunction polymer solar cell showed a high open-circuit voltage of 0.74 V and a J
 sc of 7.83 mA cm−2. This study demonstrated that significant changes in polymer electronic properties can be tuned by the strategic combination of simple electron-deficient monomers and their composition in the random terpolymers.

Fine tuning of terpolymer properties by incorporating electron-accepting difluorobenzene and diketopyrrolopyrrole units

The present invention belongs to the efficient electromagnetic wave absorber field, and concretely provides a flexible wide-angle wide spectrum efficient absorber and a manufacturing method thereof. About the flexible wide-angle wide spectrum efficient absorber, structures, namely of moth eye structures, being similar to micro-nano bulges on moth 's eyes in periodic arrangement mode are uniformly distributed at the upper surface of a substrate made by a flexible polymer, the height of each moth eye structure is 210-230 nm from the top to the bottom, the distance between adjacent moth eye structures is 390-410 nm, a metal reflecting layer, a dielectric layer and a metal nanoparticle layer are deposited on the moth eye structures in order, the metal of the metal reflecting layer is metal with high reflectivity, and the metal of the metal nanoparticle layer is precious metal. The present invention provides a simple and economical method for preparation of the flexible wide-angle wide spectrum efficient absorber on the patterning substrate.

Flexible wide-angle wide spectrum efficient absorber and manufacturing method thereof

A Conjugated Random Copolymer of Benzodithiophene-Difluorobenzene-Diketopyrrolopyrrole with Full Visible-Light Absorption for Bulk-Heterojunction Solar Cells

Yanxia Cui

Papers

Optical Curtain Effect: Extraordinary Optical Transmission Enhanced by Antireflection

Efficient Light Absorption in Organic Solar Cells Based on Two-Dimensional Arrayed Dielectric Nanospheres

Fine tuning of terpolymer properties by incorporating electron-accepting difluorobenzene and diketopyrrolopyrrole units

Flexible wide-angle wide spectrum efficient absorber and manufacturing method thereof

A Conjugated Random Copolymer of Benzodithiophene-Difluorobenzene-Diketopyrrolopyrrole with Full Visible-Light Absorption for Bulk-Heterojunction Solar Cells