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101.
We show that any embedding of the level k diamond graph of
Newman and Rabinovich [NR] into Lp, 1 < p 2, requires distortion at
least
. An immediate corollary is that there exist arbitrarily
large n-point sets
such that any D-embedding of X into
requires
. This gives a simple proof of a recent result of Brinkman
and Charikar [BrC] which settles the long standing question of whether
there is an L1 analogue of the Johnson-Lindenstrauss dimension reduction
lemma [JL]. 相似文献
102.
Shiri Artstein Keith M. Ball Franck Barthe Assaf Naor 《Journal of the American Mathematical Society》2004,17(4):975-982
It is shown that if are independent and identically distributed square-integrable random variables, then the entropy of the normalized sum
is an increasing function of .
is an increasing function of .
The result also has a version for non-identically distributed random variables or random vectors.
103.
Proton transfer along 1D chains of water molecules inside carbon nanotubes is studied by simulations. Ab initio molecular dynamics and an empirical valence bond model yield similar structures and time scales. The proton mobility along 1D water chains exceeds that in bulk water by a factor of 40, but is reduced if orientational defects are present. Excess protons interact with hydrogen-bonding defects through long-range electrostatics, resulting in coupled motion of protons and defects. 相似文献
104.
Zohar Shuali Alexander Berg Haim Levanon Emanuel Vogel Martin Brring Jonathan L. Sessler Chris Fowler Steven J. Weghorn 《Chemical physics letters》1999,300(5-6)
The photoexcited triplet state of the two new porphyrin isomers, octaethylhemiporphycene (OEHPC) and octaethylcorrphycene (OECPC), embedded in isotropic (toluene) and an anisotropic liquid crystal matrices was studied by time-resolved electron paramagnetic resonance (EPR) spectroscopy in the temperature range of 150–300 K. The magnetic, kinetic and orientation parameters were determined and interpreted in terms of structure, symmetry and dynamic. Analysis of the results suggests that at T250 K, the orientation and packing of the chromophores result from a discrete solid-like jumps mechanism, which is more efficient for OECPC. This difference is rationalized in terms of differences in the symmetry of the two chromophores. 相似文献
105.
Aviram Avital Noy Sadot Muzika Zohar Persky Gili Bar Yuval Michaeli Yulia Fridman Avishai Karny Jeny Shklover Janna Shainsky Sigal Savaldi-Goldstein Haim Weissman Oded Shoseyov Avi Schroeder 《Advanced functional materials》2021,31(44):2101003
Grapevine leafroll disease (GLD) is a globally spreading viral infection that causes major economic losses by reducing crop yield, plant longevity, and berry quality, with no effective treatment. Grapevine leafroll associated virus-3 (GLRaV-3) is the most severe, prevalent GLD strain affecting wine production. Here, the ability of RNA interference (RNAi), a non-GMO gene-silencing pathway, to treat GLRaV-3 in infected Cabernet Sauvignon grapevines is evaluated. Lipid-modified polyethylenimine (lmPEI) is synthesized as the carrier for long double-stranded RNA (dsRNA, 250-bp-long) that targets RNA polymerase and coat protein is a gene target that are conserved in the GLRaV-3 genome. Self-assembled dsRNA–lmPEI particles, 220 nm in diameter, display inner ordered domains spaced 7.3 ± 2 nm from one another, correlating to lmPEI wrapping spirally around the dsRNA. The particles effectively protect RNA from degradation by ribonucleases and show to increase uptake rate into plant cells as a result of the lipid component comprising the RNA carrier. In three field experiments, a single dose of foliar sprayed treatment of the RNA-particles knocks down GLRaV-3 titer, and multiple doses of the treatment keep the viral titer at baseline and trigger recovery of the vine and berries. This study demonstrates RNAi as a promising platform for treating viral diseases in agriculture. 相似文献
106.
107.
108.
Using an atomic force microscope we measure the interaction between two identically charged silica surfaces in the presence of a saline solution. For pure NaCl the interaction is always repulsive. Upon addition of cobalt hexamine ions, Co(NH(3))(6)(+3), the repulsion is gradually suppressed and a pronounced attraction develops at distances much shorter than the screening length. Higher concentrations of cobalt hexamine turn the attraction back into repulsion. Measurements of surface charge renormalization by the trivalent cations provide their surface density and their association constant to the negatively charged silica surface. These estimates tend to exclude interaction between two condensed Wigner crystals as an explanation for the attraction. 相似文献
109.
Zohar Shpilt Rajesh Manne Mostofa Ataur Rohman Sivaprasad Mitra Edward R.T. Tiekink Tushar S. Basu Baul Edit Y. Tshuva 《应用有机金属化学》2020,34(1):e5309
Six homoleptic Ti (IV) compounds of dianionic tridentate ONO Schiff base ligands with various substitutions were prepared from chiral amino acids, 2-hydroxybenzaldehyde, which were generated in situ, and Ti (OiPr)4. The compounds were spectroscopically characterized and the molecular geometries of five complexes were established by X-ray crystallography; for two structures, two independent molecules compose the asymmetric units. The di-anionic, tridentate ligands coordinate the titanium centers via the carboxylate-O-, imine-N- and phenoxide-O atoms to form five- and six-membered chelate rings. The molecules are based on a trans-N2O4 donor with each carboxylate-O atom trans to a phenoxide-O atom. For the smallest derivative with Me substitution, racemization occurs during repeated recrystallization. Photophysical profiles of the titanium compounds in the solid phase and in solution are discussed. Marked cytotoxicities were recorded toward human ovarian A2780 and colon HT-29 cancer cells with IC50 values ranging between 23 ± 2 and 103 ± 3 μM. Comparative hydrolytic stability of the complexes were studied by NMR in 10% D2O solutions which provided t1/2 values of up to 15 ± 2 hr. 相似文献
110.