Immersion/Electroless Deposition of Cu on Ta

Continuous Cu films are deposited on Ta by a two-step process; galvanic displacement of Ta by Cu from ammonium fluoride solutions and subsequent electroless Cu deposition from a formaldehyde-containing bath. The conditions necessary for good adhesion are discussed. The extent of oxide film removal in the HF pretreatment solution is studied by electrochemical impedance spectroscopy. The charge-transfer resistance of about 57 Ω-cm2 is several orders of magnitude lower than that measured for the Ta native oxide. These results are consistent with the removal of the Ta2O5 portion of the native oxide

Fluorescence lifetime estimation method for incomplete decay

A new incomplete decay signal model is proposed to describe the incomplete decay effects in a time- correlated single-photon counting (TCSPC) based fluorescence lifetime imaging (FLIM) system. Based on this model, we modified a MUltiple SIgnal Classification (MUSIC) algorithm to eliminate the incomplete decay effects. Monte Carlo simulations were carried out to demonstrate the performances of the proposed approach. Simulations show that the proposed method is insensitive to the laser pulse rate and has a larger lifetime dynamic range compared with previously reported approaches. As far as we know, this new method is the first non-fitting method that can resolve incomplete decay effects for multi-exponential decays

3,3′,5,5′-Tetra­bromo-2,2′-bithio­phene

The title compound, C8H2Br4S2, was prepared by bromination of 2,2′-bithio­phene with bromine. The mol­ecule is located on a crystallographic twofold rotation axis, thereby imposing equal geometry of the two thio­phene rings. Each five-membered ring is planar [maximum deviation 0.011 (9) Å] and the dihedral angle between the planes through the rings is 47.2 (4)°. The mol­ecules are arranged to minimize intramolecular contacts between the 3-3′ and 5-5′-bromine atoms

The Tractor and Semitrailer Routing Considering Carbon Dioxide Emissions

The incorporation of the minimization of carbon dioxide (CO2) emissions in the VRP is important to logistics companies. The paper deals with the tractor and semitrailer routing problem with full truckload between any two depots of the network; an integer programming model with the objective of minimizing CO2 emissions per ton-kilometer is proposed. A two-stage approach with the same core steps of the simulated annealing (SA) in both stages is designed. The number of tractors is provided in the first stage and the CO2 emissions per ton-kilometer are then optimized in the second stage. Computational experiments on small-scale randomly generated instances supported the feasibility and validity of the heuristic algorithm. To a practical-scale problem, the SA algorithm can provide advice on the number of tractors, the routes, and the location of the central depot to realize CO2 emissions decrease

The Effects of the Tractor and Semitrailer Routing Problem on Mitigation of Carbon Dioxide Emissions

The incorporation of CO2 emissions minimization in the vehicle routing problem (VRP) is of critical importance to enterprise practice. Focusing on the tractor and semitrailer routing problem with full truckloads between any two terminals of the network, this paper proposes a mathematical programming model with the objective of minimizing CO2 emissions per ton-kilometer. A simulated annealing (SA) algorithm is given to solve practical-scale problems. To evaluate the performance of the proposed algorithm, a lower bound is developed. Computational experiments on various problems generated randomly and a realistic instance are conducted. The results show that the proposed methods are effective and the algorithm can provide reasonable solutions within an acceptable computational time

Methyl 3,4-O-isopropyl­idene-2-O-[(methyl­sulfan­yl)thio­carbon­yl]-β-l-arabinoside

In the title compound, C11H18O5S2, the six- and five-membered rings adopt a chair and an approximately planar conformation, respectively

Half-Integer Shapiro Steps in a Short Ballistic InAs Nanowire Josephson Junction

We report on half-integer Shapiro steps observed in an InAs nanowire Josephson junction. We observed the Shapiro steps of the short ballistic InAs nanowire Josephson junction and found anomalous half-integer steps in addition to the conventional integer steps. The half-integer steps disappear as the temperature increases or transmission of the junction decreases. These experimental results agree closely with numerical calculation of the Shapiro response for the skewed current phase relation in a short ballistic Josephson junction

Estimation of fluorescence lifetimes via rotational invariance techniques

Estimation of signal parameters via rotational invariance techniques is a classical algorithm widely used in array signal processing for direction-of-arrival estimation of emitters. Inspired by this method, a new signal model and a new fluorescence lifetime estimation via rotational invariance techniques (FLERIT) were developed for multi-exponential fluorescence lifetime imaging (FLIM) experiments. The FLERIT only requires a few time bins of a histogram generated by a time-correlated single photon counting FLIM system, greatly reducing the data throughput from the imager to the signal processing units. As a non-iterative method, the FLERIT does not require initial conditions, prior information nor model selection that are usually required by widely used traditional fitting methods, including nonlinear least square methods or maximum likelihood methods. Moreover, its simplicity means it is suitable for implementations in embedded systems for real-time applications. FLERIT was tested on synthesized and experimental fluorescent cell data showing the potentials to be widely applied in FLIM data analysis

17α-Ethynyl-3-methoxy­estra-1,3,5(10),9(11)-tetraen-17-ol

In the title compound, C21H24O2, rings B, C and D adopt half-chair, distorted half-chair and envelope conformations, respectively. In the crystal structure, there is an inter­molecular O—H⋯O hydrogen bond. The mol­ecules are arranged in a head-to-tail fashion, with the meth­oxy and hydr­oxy groups forming a two-dimensional hydrogen-bond network