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991.
The acoustic and visual factors influencing the construction of tranquil space in urban and rural environments tranquil spaces-quiet places? 总被引:1,自引:0,他引:1
Pheasant R Horoshenkov K Watts G Barrett B 《The Journal of the Acoustical Society of America》2008,123(3):1446-1457
Prior to this work no structured mechanism existed in the UK to evaluate the tranquillity of open spaces with respect to the characteristics of both acoustic and visual stimuli. This is largely due to the fact that within the context of "tranquil" environments, little is known about the interaction of the audio-visual modalities and how they combine to lead to the perception of tranquillity. This paper presents the findings of a study in which visual and acoustic data, captured from 11 English rural and urban landscapes, were used by 44 volunteers to make subjective assessments of both their perceived tranquillity of a location, and the loudness of five generic soundscape components. The results were then analyzed alongside objective measurements taken in the laboratory. It was found that the maximum sound pressure level (L(Amax)) and the percentage of natural features present at a location were the key factors influencing tranquillity. Engineering formulas for the tranquillity as a function of the noise level and proportion of the natural features are proposed. 相似文献
992.
Wun-Chang Pan Dr. Carina Mützel Dr. Soumyajyoti Haldar Hendrik Hohmann Prof. Dr. Stefan Heinze Prof. Dr. Jeffrey M. Farrell Prof. Dr. Ronny Thomale Prof. Dr. Matthias Bode Prof. Dr. Frank Würthner Dr. Jing Qi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(15):e202400313
Replacement of sp2-hybridized carbon in polycyclic aromatic hydrocarbons (PAHs) by boron affords electron-deficient π-scaffolds due to the vacant pz-orbital of three-coordinate boron with the potential for pronounced electronic interactions with electron-rich metal surfaces. Using a diboraperylene diborinic acid derivative as precursor and a controlled on-surface non-covalent synthesis approach, we report on a self-assembled chiral supramolecular kagome network on an Ag(111) surface stabilized by intermolecular hydrogen-bonding interactions at low temperature. Scanning tunneling microscopy (STM) and spectroscopy (STS) reveal a flat band at ca. 0.33 eV above the Fermi level which is localized at the molecule center, in good agreement with tight-binding model calculations of flat bands characteristic for kagome lattices. 相似文献
993.
Davide Ranieri Dr. Alberto Privitera Dr. Fabio Santanni Dr. Karolina Urbanska Dr. Grant J. Strachan Dr. Brendan Twamley Prof. Dr. Enrico Salvadori Dr. Yu-Kai Liao Prof. Dr. Mario Chiesa Prof. Dr. Mathias O. Senge Prof. Dr. Federico Totti Prof. Dr. Lorenzo Sorace Prof. Dr. Roberta Sessoli 《Angewandte Chemie (International ed. in English)》2023,62(48):e202312936
In the development of two-qubit quantum gates, precise control over the intramolecular spin-spin interaction between molecular spin units plays a pivotal role. A weak but measurable exchange coupling is especially important for achieving selective spin addressability that allows controlled manipulation of the computational basis states |00⟩ |01⟩ |10⟩ |11⟩ by microwave pulses. Here, we report the synthesis and Electron Paramagnetic Resonance (EPR) study of a heterometallic meso-meso (m-m) singly-linked VIVO−CuII porphyrin dimer. X-band continuous wave EPR measurements in frozen solutions suggest a ferromagnetic exchange coupling of ca. 8 ⋅ 10−3 cm−1. This estimation is supported by Density Functional Theory calculations, which also allow disentangling the ferro- and antiferromagnetic contributions to the exchange. Pulsed EPR experiments show that the dimer maintains relaxation times similar to the monometallic CuII porphyrins. The addressability of the two individual spins is made possible by the different g -tensors of VIV and CuII-ions, in contrast to homometallic dimers where tilting of the porphyrin planes plays a key role. Therefore, single-spin addressability in the heterometallic dimer can be maintained even with small tilting angles, as expected when deposited on surface, unlocking the full potential of molecular quantum gates for practical applications. 相似文献
994.
Chen Cao Xin-Ran Xue Qiu-Yi Li Min-Jie Zhang Prof. Brendan F. Abrahams Prof. Jian-Ping Lang 《Angewandte Chemie (International ed. in English)》2023,62(41):e202306048
Molecular crystals with the ability to transform light energy into macroscopic mechanical motions are a promising class of materials with potential applications in actuating and photonic devices. In regard to such materials, coordination polymers that exhibit dynamic photomechanical motion, associated with a phase transition, are unknown. Herein, we report an intriguing photoactive, one-dimensional ZnII coordination polymer, 1 , derived from 1,3,5-tri-4-pyridyl-1,2-ethenylbenzene and 3,5-difluorobenzoate. Single crystals of 1 under UV light irradiation exhibit rapid shrinking and bending, violent bursting-jumping, splitting, and cracking behavior. Single-crystal X-ray diffraction analysis and 1H NMR spectroscopy reveal an unusual photoinduced phase transition involving a single-crystal-to-single-crystal [2+2] cycloaddition reaction that results in photomechanical responses. Interestingly, crystals of 1 , which are triclinic with space group , are transformed into a higher symmetry, monoclinic cell with space group C2/c. This process represents a rare example of symmetry enhancement upon photoirradiation. The photomechanical activity is likely due to the sudden release of stress associated with strained molecular geometries and significant solid-state molecular movement arising from cleavage and formation of chemical bonds. A composite membrane fabricated from 1 and polyvinyl alcohol (PVA) also displays interesting photomechanical behavior under UV light illumination, indicating the material's potential as a photoactuator. 相似文献
995.
Zhan-Yong Yang Xiao Sang Prof. Dong Liu Qiu-Yi Li Feifan Lang Prof. Brendan F. Abrahams Prof. Hongwei Hou Prof. Pierre Braunstein Prof. Jian-Ping Lang 《Angewandte Chemie (International ed. in English)》2023,62(20):e202302429
We report a unique vinyl coordination polymer (CP), [Zn(4-Fb)2(tkpvb)]n ( 1 , 4-HFb=4-fluorobenzoic acid, tkpvb=1,2,4,5-tetrakis(4-pyridylvinyl)benzene) that undergoes a rare photopolymerization reaction to form a two-dimensional CP integrated with a one-dimensional linear organic polymer. Upon light irradiation at different wavelengths, 1 exhibits an unprecedented phenomenon of photoinduced nonlinear lattice expansion. 1 can be uniformly dispersed in polyvinyl alcohol (PVA) to form the composite film of 1-PVA . When this film is exposed to UV light, internal minute stresses within crystallites are released by lattice expansion, resulting in a variety of photopolymerization-driven macroscopic mechanical motions. The findings provide new insights into the conversion of small lattice expansions of CPs into macroscopic mechanical motions based on photopolymerization reactions, which can promote the development of CPs-based smart photoactuators in the burgeoning field of microrobotics. 相似文献
996.
997.
Materials for polymer electronics applications – semiconducting polymer thin films and nanoparticles
U. Asawapirom F. Bulut T. Farrell C. Gadermaier S. Gamerith R. Güntner T. Kietzke S. Patil T. Piok R. Montenegro B. Stiller B. Tiersch K. Landfester E.J.W. List D. Neher C. Sotomayor Torres U. Scherf 《Macromolecular Symposia》2004,212(1):83-92
The paper presents two different approaches to nanostructured semiconducting polymer materials: (i) the generation of aqueous semiconducting polymer dispersions (semiconducting polymer nanospheres SPNs) and their processing into dense films and layers, and (ii) the synthesis of novel semiconducting polyfluorene-block-polyaniline (PF-b-PANI) block copolymers composed of conjugated blocks of different redox potentials which form nanosized morphologies in the solid state. 相似文献