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71.
Separation of Linear and Branched Alkanes Using Host–Guest Complexation of Cyclic and Branched Alkane Vapors by Crystal State Pillar[6]arene 下载免费PDF全文
Prof. Tomoki Ogoshi Kazuki Saito Ryuta Sueto Ryosuke Kojima Yukie Hamada Prof. Shigehisa Akine Dr. Adhitya Mangala Putra Moeljadi Dr. Hajime Hirao Dr. Takahiro Kakuta Prof. Tada‐aki Yamagishi 《Angewandte Chemie (International ed. in English)》2018,57(6):1592-1595
Activated crystals of pillar[6]arene produced by removing the solvent upon heating were able to take up branched and cyclic alkane vapors as a consequence of their gate‐opening behavior. The uptake of branched and cyclic alkane vapors by the activated crystals of pillar[6]arene induced a crystal transformation to form one‐dimensional channel structures. However, the activated crystals of pillar[6]arene hardly took up linear alkane vapors because the cavity size of pillar[6]arene is too large to form stable complexes with linear alkanes. This shape‐selective uptake behavior of pillar[6]arene was further utilized for improving the research octane number of an alkane mixture of isooctane and n‐heptane: interestingly, the research octane number was dramatically improved from a low research octane number (17 %) to a high research octane number (>99 %) using the activated crystals of pillar[6]arene. 相似文献
72.
?smail Y?lmaz Mehmet Kandaz Ali Riza ?zkaya At?f Koca 《Monatshefte für Chemie / Chemical Monthly》2002,21(2):609-622
2,3-Dibromo-6,7,13,14,15,16,22,23-octahydro-14,15-bis-(hydroxyimino)-tribenzo [e,k,q][1,4,7,10,13,16]tetraoxadiazacyclohexadecine (LH4) was prepared by condensation of 1,2-bis-(2′-aminophenoxyethoxy)-4,5-dibromobenzene with cyanogen-di-N-oxide. Mono-, di-, and trinuclear transition metal complexes of this ligand ((LH3)2Ni, (LH3)2Zn, (LH3)2Co, (LH3)2Cu, (LH3)2Fe, (LH3)2(UO2)2(OH)2, (LH)2Cu3, (LH)2Co3) were synthesized under basic conditions. The electrochemical properties of the mono- and dinuclear complexes were studied by cyclic voltammetry in DMSO solution containing TBAP. The results showed that all redox processes are based on the metal center and the oxime ligands stabilize the Ni(III), Fe(III), Co(III), and Cu(III) species formed during oxidation. The Fe(II) and U(VI)O2 complexes displayed a different behaviour: a reduction peak with the corresponding anodic signal during the reverse scan was observed. The oxime moiety also stabilizes U(V)O2 which forms during the reduction process of the uranyl complex. Cu(II) was adsorbed on the electrode surface upon scanning cathodically. 相似文献
73.
Photoelectron spectra of six 8,11-disubstituted pentacycloundecanes (1, 3 - 7) are reported; the results suggest that the through-space interaction betweeen unsaturation centers in 1 and 3 dominates over the through-bond interaction mechanism. 相似文献
74.
Acousto-optic device-based high-speed high-isolation photonic switching fabric for signal processing
Riza NA 《Optics letters》1997,22(13):1003-1005
A high-speed, switched, binary photonic switching fabric based on two acousto-optic devices arranged in a compact self-aligning (by acousto-optic device-based Bragg matching) optical geometry is introduced for photonic signal processing and control. This fabric has the unique capability to provide simultaneously both high switching speeds and high optical isolation, a critical need for advanced low-noise high-speed signal-processing applications. The proof-of-concept experimental fabric demonstrated nearly 60% light throughput, a 39-dB optical isolation level for both states of the switching fabric, and a 138-ns switching time. 相似文献
75.
A binary multichannel photonic delay line (PDL) module is introduced that gives balanced loss switched states and a polarization-insensitive operation via the use of binary operation Digital Micromirror Devices (DMDs). Experimental demonstration of a DMD-based PDL architecture is performed for a 6.84-ns time delay design. Experimental results include a 25-beam feed interchannel crosstalk test indicating a <−60 dB optical interchannel crosstalk level for a 0.381 mm interchannel distance in the multichannel PDL. An average optical signal-to-leakage noise ratio of 35.33 dB is measured for this PDL. A butterfly design PDL optical architecture is proposed for minimizing loss and improving assembly accuracy. These DMD-based variable PDLs can be used in applications ranging from radio frequency (RF) fiber-optic signal processing systems to adaptive optics for astronomical and laser radar arrays. 相似文献
76.
B. Budič 《Analytical and bioanalytical chemistry》2000,368(4):371-377
The use of inductively coupled plasma atomic emission spectrometry with ultrasonic nebulization (USN-ICP-AES) for determining
Ag, Al, As, Ba, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sb, Sr, V and Zn in complex matrices of Ca, Na, K and P in waste
waters is described. Generally, depressions in the analyte emission intensity occur in the presence of concomitants. Matrix
interferences can be minimized by increasing the operating power and lowering the carrier gas flow rate. However, the enhancement
of the signal-to-background ratios (SBRs) shows an opposite trend. Therefore, routine analyses were performed at a compromise
power setting of 1350 W, a carrier gas flow rate of 0.8 L min–1 and an observation height of 14 mm above the load coil and using a matrix matched calibration procedure. Limits of detection
(LODs) at chosen operating conditions were at μg L–1 levels for most of the elements studied, including mercury when KBr is added to the analyte solution to enhance sensitivity.
LODs were not significantly changed in the presence of matrix elements. Recoveries for the majority of added elements from
spiked waste water samples are between 93 and 105% using a matrix matched calibration.
Received: 13 January 2000 / Revised: 10 April 2000 / Accepted: 18 April 2000 相似文献
77.
Vignesh Sekar Se Yong Eh Noum Azma Putra Sivakumar Sivanesan Kok Chun Chin Yi San Wong Dg Hafizah Kassim 《声与振动》2021,55(4):343-352
This paper presents the development and performance of micro-perforated panels (MPP) from natural fiber reinforced composites. The MPP is made of Polylactic Acid (PLA) reinforced with Oil Palm Empty Fruit Bunch Fiber (OPEFBF). The investigation was made by varying the fiber density, air gap, and perforation ratio to observe the effect on the Sound Absorption Coefficient (SAC) through the experiment in an impedance tube. It is found that the peak level of SAC is not affected, but the peak frequency shifts to lower frequency when the fiber density is increased. This phenomenon might be due to the presence of porosity in the inner wall of the holes. Increasing or decreasing the air gap and perforation ratio shifts the peaks of acoustic absorption either way. 相似文献
78.
The unsteady shock wave diffraction over a 90° sharp corner in gases of arbitrary particle statistics is simulated using an
accurate and direct algorithm for solving the semiclassical Boltzmann equation with relaxation time approximation in phase
space. The numerical method is based on the usage of discrete ordinate method for discretizing the velocity space of the distribution
function; whereas a second order accurate TVD scheme (Harten in J. Comput. Phys. 49(3):357–393, 1983) with Van Leer’s limiter (J. Comput. Phys. 32(1):101–136, 1979) is used for evolving the solution in physical space and time. The specular reflection surface boundary condition is assumed.
The complete diffraction patterns are recorded using various flow property contours. Different range of relaxation times approximately
corresponding to continuum, slip and transitional regimes are considered and the equilibrium Euler limit solution is also
computed for comparison. The effects of gas particles that obey the Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac statistics
are examined and depicted. 相似文献
79.
Spectral hole burning (SHB) effects in a gain-flattened erbium-doped fiber amplifier (EDFA) are demonstrated to be significant in the presence of large signal power around the 1530-1532-nm wavelength range. These are the first effects reported in a setup employing equivalent power level distribution of 40 channels ranging from 1530 to 1561 nm. To explain this, the introduction of a new local population variable into the laser equation is required to support the original inversion ratio that is determined by the pump lasers. In the analysis section, spectroscopic parameters and high signal powers are considered to be other contributing parameters to the change in the gain characteristics. An improvement to this theoretical basis is suggested by implementing mathematical modeling to validate similarities between the gain shape of simulation to that obtained in the experiment. 相似文献
80.
Fauzia Izzati Mega Ferdina Warsito Asep Bayu Anggia Prasetyoputri Akhirta Atikana Linda Sukmarini Siti Irma Rahmawati Masteria Yunovilsa Putra 《Molecules (Basel, Switzerland)》2021,26(7)
Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007–2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates. 相似文献