Miracle-dz/UniFAR-FTUs huggingface dataset:
Assessment of detector calibration materials for SANS experiments

The properties of incoherent-scattering samples that are used as calibrants for small-angle neutron scattering (SANS) experiments have been investigated using time-of-flight analysis of the wavelengths of the scattered neutrons. Such samples are employed both as secondary intensity standards and to calibrate the relative efficiency of detectors. The data show that care must be taken to allow for wavelength dependence of the detector efficiency if the measured results are to be understood or compared with respect to different instruments. At ambient temperatures, glassy polymer sheets of poly(methyl methacrylate) or polycarbonate offer better performance as secondary standards than water. The results reveal the limits for the use of transmission measurements to estimate incoherent scattering cross sections. Use of uniform scattering as a basis for a measure of the effective cross section is, in practice, instrument dependent, owing to extensive inelastic multiple scattering.
Sensitivity of the aggregation behaviour of asphaltenes to molecular weight and structure using molecular dynamics

Asphaltenes are heavy crude oil compounds, defined as soluble in toluene and precipitating in alkanes. To understand the relation between asphaltene structure and aggregation, we perform equilibrium molecular dynamics with Large-scale Atomic and Molecular Massively Parallel Software (LAMMPS), using the atomistic force field PCFF+ in the MedeA® environment. The following three molecular models are considered: the continental model (1350 g/mol) that has a large polyaromatic core and long alkyl chains, the island model (780 g/mol) that has a smaller polyaromatic unit and shorter chains and the archipelago model (1350 g/mol) that has three polyaromatic nuclei bridged with alkyl chains. The aggregation in a given solvent is monitored by visualising solvent-free configurations over 15 ns trajectories at 350 K. Nanoaggregates are characterised by stacked polyaromatic units separated by 0.33–0.4 nm. Irreversible aggregation is found with the continental model in both solvents. Aggregation of the island model is significant in n-heptane and low in toluene. The archipelago model does not aggregate significantly. Our results confirm that the island model is a reasonable average model of asphaltenes [Headen TF, Boek ES, Skipper NT. Energy Fuels 2009;23:1220–1229]. The open structure of nanoaggregates and the limited number of stacked molecules are also in agreement with previous interpretations of experimental data [Fenistein D. et al. Langmuir 1998;14:1013–1020].
Hierarchical Cu-Co-Ni nanostructures electrodeposited on carbon nanofiber modified glassy carbon electrode: Application to glucose detection

Hierarchical Cu–Co–Ni nanostructures (Cu–Co–Ni NSs) attached to carbon nanofibers (CNFs) modified glassy carbon electrode (GCE) was prepared by electrodeposition. Scanning electron microscopy results indicated that many hierarchical Cu–Co–Ni NSs were formed and uniformly dispersed on the CNFs/GCE surface. The electrochemical behavior and electrocatalytic performance of the Cu–Co–Ni NSs/CNFs/GCE towards the oxidation of glucose were evaluated by cyclic voltammograms, chronoamperometry and amperometric methods. The results revealed that Cu–Co–Ni NSs/CNFs/GCE has a good electrocatalytic activity for glucose oxidation and could be used as a nonenzymatic glucose sensor. The sensor showed an acceptable linear range from 0.01 to 4.30 mM with a sensitivity of 104.68 μA mM cm−2, and a detection limit of 3.05 μM (S/N = 3). The good catalytic activity, high sensitivity, good selectivity and stability rendered the Cu–Co–Ni NSs/CNFs/GCE to be a promising electrode for constructing a nonenzymatic glucose sensor.
Thickness and Air Gap Dependence of Macrovoid Evolution in Phase-Inversion Asymmetric Hollow Fiber Membranes

We have studied, for the first time, the effects of spinneret dimension and its coupling effect with air gap distance on macrovoid evolution. Spinnerets with different annulus gaps, i.e., from 0.05 to 0.50 mm, were fabricated. Hollow fiber membranes spun from thinner spinneret annulus gaps show only inward-pointed long, teardrop, and elliptical shape macrovoids, while those spun from thicker annulus gaps have both inward- and outward-pointed macrovoids. On the basis of SEM examination, it is concluded that nonsolvent intrusion due to local surface instability and skin rupture accounts for most inward- and outward-pointed long macrovoid formation, while the diffusion mechanism with the aid of solutocapillary convection possibly accounts for the formation of small teardrop and elliptical shape macrovoids. In addition, the number of inward-pointed macrovoids increases, while the number of outward-pointed macrovoids decreases with an increase in air gap distance. Clearly, many forces affecting macrovoid forma.
Measured and simulated electron energy distribution functions in a low‐pressure radio frequency discharge in argon

We report a combined experimental and computational study of a low‐pressure radio frequency discharge in argon. We have determined the electron energy distribution function experimentally using a Langmuir probe system and by simulation using the particle in cell method. A close comparison of these data shows good agreement over pressures from 20 to 200 mTorr. This pressure range encompasses the putative transition from a stochastic to an ohmic electron heating mode [V. A. Godyak and R. B. Piejak, Phys. Rev. Lett. 65, 996 (1990)]. The simulation does show such a transition, and we agree with earlier estimates of the transition pressure.
Vertical GaN-based trench metal oxide semiconductor field-effect transistors on a free-standing GaN substrate with blocking voltage of 1.6 kV

This paper reports the characteristics of vertical GaN-based trench metal–oxide–semiconductor field-effect transistors on a free-standing GaN substrate with a blocking voltage of 1.6 kV. The high blocking voltage was obtained by using field plate edge termination around the isolation mesa of the transistor. To our knowledge, the blocking voltage is the highest ever reported for vertical GaN-based transistors on free-standing GaN substrates. Normally off operation with a threshold voltage of 7 V is also demonstrated.
Design, fabrication and experiment of dataset acquisition apparatus for dual imaging plane

Target tracking plays an important role in monitoring, security, pedestrian recognition and other fields. The imaging system of a single imaging plane is limited by hardware conditions, and sometimes is not competent for increasingly complex image processing tasks. Therefore, it is a natural choice to obtain better tracking effect by multi imaging plane cooperative system. When the target tracking network algorithm is implemented for the dual imaging plane system, the data set acquisition of image is indispensable. According to this requirement, we designed and fabricated an image data acquisition apparatus, which includes a set of optical system, two sets of imaging circuits and structural components. After the apparatus integration is completed, we acquire the image data and implement the target tracking experiment based on correlation filtering method. The experiment shows that the tracking accuracy and tracking success rate of correlation filtering algorithm are significantly improved compared with the method using single imaging plane information after using the dataset constructed by this apparatus.
Gyroid‐Structured 3D ZnO Networks Made by Atomic Layer Deposition

3D continuous ZnO morphologies with characteristic feature sizes on the 10 nm length scale are attractive for electronic device manufacture. However, their synthesis remains a challenge because of the low crystallization temperature of ZnO. Here, we report a method for the robust and reliable synthesis of fully crystalline 3D mesoporous ZnO networks by means of atomic layer deposition (ALD) of ZnO into a self‐assembled block copolymer template. By carefully optimizing the processing conditions we are able to synthesize several‐micrometer‐thick layers of mesoporous ZnO networks with a strut width of 30 nm. Two 3D mesoporous morphologies are manufactured: a periodic gyroid structure and a random worm‐like morphology. Exploiting the ALD property to conformally coat complex surfaces of high aspect ratio, the channel network of a 3D continuous channel network of a self‐assembled block copolymer is replicated into ZnO. X‐ray photoemission spectroscopy and x‐ray diffraction measurements reveal that the chemical composition of the mesoporous structures is uniform and consists of wurtzite‐ZnO throughout the film. Scanning electron microscopy reveals an average pore dimension of 30 nm. The potential of this material for a hybrid photovoltaic application is demonstrated by the manufacture of a poly(3‐hexylthiophene)/ZnO solar cell.
Quantitative analysis of the inelastic background in surface electron spectroscopy

Recent progress, in the quantitative analysis of the distortion of surface electron spectra, resulting from inelastic electron scattering, is reviewed. A physical model for the problem is formulated and based on this, basic deconvolution formulae are found. In the formulae, detailed information on the differential inelastic electron scattering cross-section K is essential. Methods to determine,K are studied and developed. One method is based on a dielectric response calculation. Furthermore, it is found that for the noble and transition metals, K is sufficiently similar that a simple ‘universal’ cross-section can be defined. In addition, methods for experimental determination of cross-sections are found and in particular a formula is derived which allows the extraction of direct quantitative cross-section information through a simple analysis of REELS spectra. The importance of proper background correction is investigated for model electron spectra. Experimental XPS spectra are also studied and it is found that for both the simple and the noble metals, the primary excitation spectra extend 2–3 inelastic scattering events, i.e. ∼50 eV, below the peak energy. Beyond this energy, the spectra are of zero intensity over a wide energy range. Besides, experimental spectra are analysed on the basis of experimentally determined cross-sections and the results are discussed, in relation to the analysis based on theoretical cross-sections. The importance of defining simple procedures for routine analysis of spectra is stressed and it is demonstrated that the proposed ‘universal’ cross-section provides a very simple method for approximate spectral analysis. Finally, some important issues to be considered in the near future are pointed out.
Synthesis of colloidal crystals of controllable thickness through the Langmuir-Blodgett technique

Colloidal crystals of various thicknesses were obtained using silica particles as basic units and the Langmuir−Blodgett technique as a tool for controlling the thickness. Submicronic silica particles are first synthesized via a sol−gel process and then functionalized with an appropriate coupling agent. After compression at the surface of a Langmuir trough to form a well-organized two-dimensional array, silica particles are transferred onto solid substrates. While repeating the transfer several times, we formed colloidal crystals that were characterized by scanning electron microscopy and UV−visible−NIR spectroscopies. Both techniques show that the sample thickness can be controlled at the layer level whereas the overall crystal quality should be good enough for use in several applications.
Loss of cell components during rehydration of dried Rhodotorula glutinis and its implications for lead uptake

Microbial cells are routinely dried and ground before they are used in metal biosorption studies. In this work, a metal biosorbent was prepared by drying biomass of the yeast Rhodotorula glutinis in an oven at 70°C for 24 h followed by grinding. Two forms of the prepared biosorbent particles, washed and unwashed, were examined for their ability to remove lead from solution. It was found that the unwashed biosorbent exhibited higher lead uptake than the washed biosorbent. Analysis of the supernatant of washed cells incubated in water and that of unwashed cells incubated in lead solution revealed the presence of protein, carbohydrates, organic acids and inorganic phosphate. Overall, the washed and unwashed cells leached, respectively, 14.5 and 13.4% of their initial dry weight (100 mg). Acid‐base titration data revealed that the leached components contained several potential binding sites for metal cations with carboxyl and phosphoryl groups being particularly important. The higher level of lead uptake exhibited by the unwashed biomass was attributed to the fact that it leached smaller amounts of cell constituents with proton binding sites relative to the washed cells.
Methods of Loading and Releasing Low Molecular Weight Cationic Molecules in Weak Polyelectrolyte Multilayer Films

This work studied the loading capabilities and release behavior of poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) multilayer films, using methylene blue dye (MB) as an indicator. PAA/PAH multilayers assembled at pH = 2.5/2.5 loaded MB throughout the multilayers due to available binding sites and a permeable structure. The amount of MB loaded increased linearly with increasing film thickness. Use of buffered MB solutions enabled faster and more uniform MB loading into the multilayers, because ions within the MB solution caused further swelling of the multilayer film. Release studies demonstrated a pH-sensitive release mechanism, where lower pH environments increased the release rate. Buffered environments also increased the release rate of MB from the multilayer films. By assembling capping layers of PAA/PAH at pH 6.5/6.5 on top of 2.5/2.5 PAA/PAH multilayers, the diffusion of MB through the multilayers was better controlled under nonbuffered conditions. Under buffered conditions, howeve.
Investigating Radio Frequency Plasmas Used for the Modification of Polymer Surfaces

By use of Langmuir probes and energy-resolved mass spectrometry, the properties of a cold plasma suitable for the surface treatment of polymers are investigated. The 13.56 MHz radio frequency (rf) excitation is provided by an external coil, and we demonstrate that a plasma of Ar gas is capacitively coupled to the source coil. The spatial distributions of plasma and floating (self-bias) potentials, electron temperature Te, and plasma density ne have been investigated for a range of input powers (1−50 W) and gas pressures (10-3−10-1 Torr) using compensated Langmuir probes. Estimates of the rf potential amplitudes are also given. The energy distribution of plasma ions at plasma boundaries has also been measured, and the effect of the perturbation to the plasma parameters due to the presence of the polymer sample and the spectrometer has been quantified. A feature of these plasmas is the presence of large rf potentials (up to about 25Te) and high self-bias potentials (up to 80 V). We show that the presence of.
Optimization of CdTe Quantum Dots Synthesis Using Capillary Zone Electrophoresis

Abstract: Water-soluble, thiol protected cadmium telluride CdTe quantum dots (QDs) exhibit size dependent excitation/emission wave-length tunability. The heating period ensuring the growth of CdTe nanocrystals capped with thioglycolic acid (CdTe@TGA) in aqueous solution is critical to reach a required/desirable diameter. Thus, reaction medium was monitored using a capillary zone electrophoresis (CZE) technique in order to select an appropriate heating time. QDs migrate as anionic species in a borate buffer pH 8.5 used as back-ground electrolyte and they were separated according to their size (larger ones have shorter migration times), as confirmed by measuring their maximum wavelength of absorption, with on-line diode array detection. A relationship between electrophoretic mobilities and  max was tentatively proposed. Efficiency of the purification process of crude QDs using multiple step alcohol precipitation was also con-firmed with the developed CZE technique. Keywords: quantum dots, synthesis, size-selective precipitation, capillary zone electrophoresis, diode array detection, size-dependent migra-tion.
Novel Condensed Ring Carboxylic Hydroxamic Acid Studied in the Flotation Behavior of Diaspore and Aluminosilicates

Flotation reagents are the critical technique in the flotation separation process for desilication. Aimed at the highly selective reagent for direct flotation of diasporic bauxite, a novel compound, dibenzo-1-(7-carboxyl-4-hydroxyl bicycle [2.2.2] octan-7,8-diyl) carboxamic acid (DBCA) with two functional groups carboxyl and hydroxamate in the same molecule, was synthesized through Diels-Alder reaction followed by oximation reaction. Subsequently, the floatability of diaspore, kaolinite, and illite was measured by using DBCA as a collector, the interaction mechanism between minerals and DBCA was investigated through zeta potential measurements and FT-IR spectrum, and the structure and property relationship of the collector were also discussed. The flotation experimental results showed that DBCA had a very strong collecting ability for diaspore, while poor activity was observed for kaolinite and illite. The interaction of DBCA on diaspore surfaces may be mainly dominated by chemical bonding as the formation of three chelation rings; however, those on the surfaces of kaolinite and illite are mainly hydrogen bonding or physical adsorption. Consequently, it is possible to separate diaspore from such aluminosilicates as kaolinte and illite employing DBCA as a collector.
Synthesis and properties of sulfur dioxide adducts of organophosphinecopper(I) iodides. Structures of the dinuclear compounds tetrakis(methyldiphenylphosphine)di-.mu.-iodo-dicopper(I)-sulfur dioxide and tris(triphenylphosphine)di-.mu.-iodo-dicopper(I)

Compounds of the general formula Cu/sub m/I/sub m/(PR/sub 3/)/sub n/ . xSO/sub 2/, where PR/sub 3/ = PPh/sub 3/, PPh/sub 2/Me, PBzl/sub 3/, and PCy/sub 3/ (Bzl = benzyl; Cy = cyclohexyl), are formed by direct reaction of SO/sub 2/ with organophosphine copper (I) iodide complexes. The nature of the reaction solutions and isolated products has been elucidated by spectroscopic, tensimetric, and x-ray diffraction methods. Sulfur dioxide complexation occurs only at the coordinated halogen, even when three-coordinate copper (I) apparently is present in the complex. The strength of interaction is a strong function of both the specific phosphine and stoichiometry, and the bright yellow to orange crystalline complexes have SO/sub 2/ dissociation pressures of 2 to 70 Torr at ambient temperature. The crystal structure analysis of Cu/sub 2/I/sub 2/(PPh/sub 2/Me)/sub 4/ . SO/sub 2/ reveals a dimeric, di-. mu. -iodo-bridged structure involving pseudotetrahedral copper atoms and an SO/sub 2/ group bound weakly as a Lewis acid to one of the bridging iodides (I--S = 3.407 (5) A and I--S--O = 98.1 (6), 114.5 (8)/sup 0/). Additionally, we report the structure of the compound Cu/sub 2/I/sub 2/(PPh/sub 3/)/sub 3/ and its interaction with sulfur dioxide. X-ray structure determination reveals a dinuclear unit similarmore » to that found in Cu/sub 2/Cl/sub 2/(PPh/sub 3/)/sub 3/ with . mu. -iodide bridges and both three-coordinate copper and four-coordinate copper. Pertinent crystallographic data are as follows: Cu/sub 2/I/sub 2/(PPh/sub 3/)/sub 3/, space group P2/sub 1/, a = 11.763 (4) A, b = 20.682 (4) A, c = 10.527 (3) A, . beta. = 105.66 (2)/sup 0/, Z = 2, R = 0.047 for 4139 diffractometric reflections (with I greater than or equal to 3sigma(I) and 2theta less than or equal to 60/sup 0/); Cu/sub 2/I/sub 2/(PPh/sub 2/Me)/sub 4/SO/sub 2/, space group P anti l, a = 20.02 (2) A, b = 12.062 (6) A, c = 14.898 (7) A, . cap alpha. = 116.30 (3)/sup 0/, . beta. = 68.44 (3)/sup 0/, . gamma. = 124.89 (2)/sup 0/, Z = 2, R = 0.052 for 7112 diffractometric reflections (with I greater than or equal to 3sigma(I) and 2sigma less than or equal to 50/sup 0/). « less
A third polymorph of (2-thiazolidinethionato)-(triphenylphosphine)gold(I)

The title compound, [Au(C3H4NS2)(C18H15P)], is a third polymorphic form of a compound previously reported by Grant, Forward & Fackler Jr [Z. Kristallogr. (1996). 211, 483–484]. At 100 K, the present polymorph shows triclinic symmetry, as do the other two polymorphs.
What drives Bitcoin fees? Using SegWit to assess Bitcoin’s long-run sustainability

We use block level data from the Bitcoin blockchain to estimate the impact of congestion and the USD price on average fee rates. The introduction and adoption of the Segwit protocol allows us to identify an aggregate demand curve for bitcoin transactions. We nd that Segwit has reduced fee revenue by about 80%. Fee revenue could be maximized at a blocksize of about 0.6 MB when Segwit adoption remains at 40%. At this blocksize, maximum fee revenue would be roughly 1/8 of the current block reward { or the equivalent of 1.6375 BTC as a reward in the long run given current prices and demand for Bitcoin.
Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.
Adsorption of Pd(II), Pt(IV), and Rh(III) on a Ligand Encapsulated Polymer Resin Assisted by Thermal Heating or Microwave Irradiation

A new chelating resin (R-N resin) was prepared through the encapsulation of linear poly(octadecylvinyl−maleic anhydride) into a porous polyacrylate support (Amberlite XAD−7) with subsequent grafting of 2−aminomethylpyridine. Adsorption characteristics of the chelating resin for platinum group metals (Pd(II), Pt(IV), Rh(III)) were examined with respect to the adsorption rate and dependence on pH and temperature. The adsorption reaction of Pd(II) and Pt(IV) at pH 2 in the presence of Cl− ion (0.1 M) was exothermic, whereas that of Rh(III) was endothermic. Ion exchange reaction by electrostatic attraction between the protonated ligand with [PdCl4]2− and [PtCl6]2− is predominant for the adsorption of Pd(II) and Pt(IV) at pH 2.0. While Rh(III) was retained by a complex formation from pH 2.0 to pH 6.5, adsorption of Rh(III) was remarkably accelerated by microwave irradiation: more than 91% of Rh(III) was retained for 1 h, while it was less than 50% by conventional heating. Repeated use of resin after regeneration was also demonstrated.
Shock compression of liquid hydrogen

High explosives have been used to shock liquid hydrogen to 39 500 bars, 5·2 cm3/g and an estimated temperature of 1100°k from an initial state near the normal boiling point, 20·5°k and 14·1 cm3/g. How far the melting curve and the equation of state can be pursued by shock wave experiments is discussed. The derived intermolecular potential between two hydrogen molecules is shown to be inadequately represented by the previously postulated Lennard-Jones 6–12 potential in the repulsive region between 2·0 and 2·7 A. The power of the inverse intermolecular distance is shown instead to be 8·5 in that region if a purely repulsive potential is used.