A theoretical mode for the instability of turbulent boundary layer over compliant surface

A theoretical model for the instability of turbulent boundary layer over compliant surfaces is described. The investigation of instability is carried out from a time-asymptotic space-time perspective that classifies instabilities as either convective or absolute. Results are compared against experimental observations of surface waves on elastic and viscoelastic compliant layers.     

R~n上加权弱Hardy空间中的Calderón-Zygmund型算子

作者引进了某些 Ｃａｌｄｅｒóｎ－Ｚｙｇｍｕｎｄ型算子,并且讨论了它们在加权 Ｌｅｂｅｓｇｕｅ空间、加权弱Ｌｅｂｅｓｇｕｅ空间、加权Ｈａｒｄｙ空间和加权弱Ｈａｒｄｙ空间上的有界性．作者也考察了一些结果的尖锐性．     

Passive micromixer for luminol-peroxide chemiluminescence detection

This paper reports a microchip with an integrated passive micromixer based on chaotic advection. The micromixer with staggered herringbone structures was used for luminol-peroxide chemiluminescence detection. The micromixer was examined to assess its suitability for chemiluminescence reaction. The relationship between the flow rate and the location of maximum chemiluminescence intensity was investigated. The light intensity was detected using an optical fiber attached along the mixing channel and a photon detector. A linear correlation between chemiluminescence intensity and the concentration of cobalt(ii) ions or hydrogen peroxide was observed. This microchip has a potential application in environmental monitoring for industries involved in heavy metals and in medical diagnostics.     

Tunable spin loading and T1 of a silicon spin qubit measured by single-shot readout

We demonstrate single-shot readout of a silicon quantum dot spin qubit, and we measure the spin relaxation time T1. We show that the rate of spin loading can be tuned by an order of magnitude by changing the amplitude of a pulsed-gate voltage, and the fraction of spin-up electrons loaded can also be controlled. This tunability arises because electron spins can be loaded through an orbital excited state. Using a theory that includes excited states of the dot and energy-dependent tunneling, we find that a global fit to the loading rate and spin-up fraction is in good agreement with the data.     

Odd-even behavior of ferroelectricity and antiferroelectricity in two homologous series of bent-core mesogens

Two chiral bent-core mesogens Pn-O-PIMB(n - 2)* (n = 9 and 10) and their oxygen analogues Pn-O-PIMB(n - 2)*-(n - 4)O (n = 8, 9, and 10) with omega-[(S)-amyloxy]alkoxy terminal groups were prepared, and their phase structures were investigated by means of electro-optic, polarization reversal current and second harmonic generation measurements in order to clarify the effect of the interlayer steric interaction on the emergence of polar orderings. The odd-even behavior for the alternative appearance of ferroelectricity and antiferroelectricity was observed in two homologous series; the bent-core mesogens P10-O-PIMB8*, P8-O-PIMB6*-4O, and P10-O-PIMB8*-6O in addition to the previously reported P6-O-PIMB4* and P8-O-PIMB6*, where the length of chains n is even, exhibited ferroelectric phases. On the contrary, the mesogens P7-O-PIMB5*, P9-O-PIMB7*, and P9-O-PIMB7*-5O, where n is odd, showed antiferroelectric phases. It is obvious that the interlayer steric interaction plays a major role for the emergence of a variety of phase structures.     

Influences of Seven Taiwan‐Produced Adulterants on Gas Chromatographic‐Mass Spectrometric (GC‐MS) Urinalysis of Amphetamines

This study was conducted to better understand the influences exerted by seven Taiwan‐produced adulterants on the forensic gas chromatographic‐mass spectrometric (GC‐MS) confirmatory urinalysis of amphetamines. The results verified that, when added at 5‐15% (w/w), chlorine bleach would lower the GC‐MS outcomes of the spiked and case specimens by 36‐63%, and was most likely to cause false negatives. Liquid soap, potassium dichromate, soda water for drinking, and tap water would decrease the GC‐MS outcomes by 9‐29%, 8‐20%, 8‐20%, and 5‐16%, respectively, and also had the risk of negating near‐cutoff initial positives into false confirmatory negatives. The negative‐directing effects were mostly due to degradation of analytes and/or deactivation of the derivatizing agent by oxidizing adulterants and/or dilution of analytes by the added liquid. Alum and table salt added as powder had little impact on the test. Responsible institutions and relevant laboratories should face the facts seriously and include the specimen validity testing (SVT) battery in the routine drug testing procedures.