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991.
Formation of a Macrocycles‐in‐a‐Macrocycle Superstructure with All‐gauche Conformation by Reversible Radical Association
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Dr. Liu Yuan Yi Han Prof. Tao Tao Dr. Hoa Phan Prof. Chunyan Chi 《Angewandte Chemie (International ed. in English)》2018,57(29):9023-9027
The formation of an unprecedented macrocycles‐in‐a‐macrocycle (MIM) superstructure by reversible radical–radical association of a triphenylamine based monomer terminated with three dicyanomethyl radicals is presented. The reaction yield is nearly quantitative and the obtained macrocycle contains three small dimeric macrocycles according to X‐ray crystallographic analysis. The six monomer molecules are linked by nine long dynamic covalent C(sp3)?C(sp3) bonds that all adopt a gauche conformation. Such a conformation favors the formation of a MIM structure rather than a 2D network with an all‐anti conformation. Two enantiomers with left‐/ right‐handed chirality exist in the single crystals of the superstructure. 相似文献
992.
Back Cover: Single‐Nanoparticle Cell Barcoding by Tunable FRET from Lanthanides to Quantum Dots (Angew. Chem. Int. Ed. 41/2018)
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993.
Hua Xiao Chi Chung Wong G. K. Reeves 《Journal of Thermal Analysis and Calorimetry》1997,48(6):1293-1298
This paper describes the thermal modelling results for a thin film resistor array which can have applications in infrared scene projection. In this design, the array consists of two parallel rows of resistor elements. A central aluminium busbar which forms a common electrical connection for all resistor elements, also provides thermal isolation between the two rows through thermal connection to the array substrate. It is shown that the thickness of the aluminium busbar of the order of 2 m is sufficient to provide good thermal isolation, thus allowing an increase in the pixel fill factor. 相似文献
994.
Patrick Chiu 《Proceedings of the American Mathematical Society》1997,125(3):723-730
Relations between the height and the determinant of the Laplacian on the space of -dimensional flat tori and the classical formulas of Kronecker and Epstein are established. Extrema of the height are shown to exist, and results for a global minimum for 2-d tori and a local minimum for 3-d tori are given, along with more general conjectures of Sarnak and Rankin.
995.
We present a noiseless optical amplifier comprising a signal-amplifying feed-forward loop and a power-amplifying injection-locked laser. We demonstrate that the signal amplifier can attain a signal-transfer coefficient limited solely by the quantum efficiency of our in-loop photodetector and that we can independently amplify the optical power while leaving the normalized intensity-noise spectral density of the input field unchanged. 相似文献
996.
Chen-Tsung Shih Tang-Jung Huang Ying-Zi Luo San-Min Lan Kuan-Cheng Chiu 《Journal of Crystal Growth》2005,280(3-4):442-447
This work investigates the growth of polycrystalline α-HgI2 thick films from physical vapor deposition. By varying the growth conditions, the as-deposited thick films are characterized by scanning electron microscopy, X-ray diffraction, current–voltage and photoconductivity measurements. The growth mechanism and its effects to the properties of these polycrystalline α-HgI2 thick films are then discussed. Finally, the best deposition conditions for polycrystalline α-HgI2 thick films compactly formed by separated columnar monocrystallines with uniform orientation along c-direction and with good crystallinity are reported. 相似文献
997.
Fragmentation of protonated RVYIHPF and RVYIHPF-OMe and the corresponding radical cations was studied using time- and collision energy-resolved surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially equipped to perform SID experiments. Peptide radical cations were produced by gas-phase fragmentation of Co (III)(salen)-peptide complexes. Both the energetics and the mechanisms of dissociation of even-electron and odd-electron angiotensin III ions are quite different. Protonated molecules are much more stable toward fragmentation than the corresponding radical cations. RRKM modeling of the experimental data suggests that this stability is largely attributed to differences in threshold energies for dissociation, while activation entropies are very similar. Detailed analysis of the experimental data obtained for radical cations demonstrated the presence of two distinct structures separated by a high free-energy barrier. The two families of structures were ascribed to the canonical and zwitterionic forms of the radical cations produced in our experiments. 相似文献
998.
Biological assays at the single molecule level are crucial to fundamental studies of DNA-protein mechanisms. In order to cater
for high throughput applications, one area of immense research potential is single-molecule bioassays where miniaturized devices
are developed to perform rapid and effective biological reactions and analyses. With the success of various emerging technologies
for engineering miniaturized structures down to the nanoscale level, supported by specialized equipment for detection, many
investigations in the field of life science that were once thought impossible can now be actively explored. In this review,
the significance of downscaling to the single-molecule level is firstly presented in selected examples, with the focus placed
on restriction enzyme assays. To determine the effectiveness of single-molecule restriction enzyme reactions, simple and direct
analytical methods based on DNA stretching have often been reliably employed. DNA stretching can be realized based on a number
of working principles related to the physical forces exerted on the DNA samples. We then discuss two examples of a nanochannel
system and a microchamber system where single-molecule restriction enzyme digestion and DNA stretching have been integrated,
which possess prospective capabilities of developing into highly sensitive and high-throughput restriction enzyme assays.
Finally, we take a brief look at the general trends in technological development in this field by comparing the advantages
and disadvantages of performing assays at bulk, microscale and single-molecule levels.
Figure Minaturization of Restriction Enzyme Assays and DNA Stretching 相似文献
999.
Bc(G) denotes the cyclic bandwidth of graph G. In this paper, we obtain the maximum cyclic bandwidth of graphs of order p with adding an edge as follows:
1000.