Molecules have extremely small absorption cross sections in the terahertz range even under resonant conditions, which severely limit their detectability, often requiring tens of milligrams. We ...demonstrate that nanoantennas tailored for the terahertz range resolves the small molecular cross section problem. The extremely asymmetric electromagnetic environment inside the slot antenna, which finds the electric field being enhanced by thousand times with the magnetic field changed little, forces the molecular cross section to be enhanced by >103 accompanied by a colossal absorption coefficient of ∼170 000 cm–1. Tens of nanograms of small molecules such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and lactose drop-cast over an area of 10 mm2, with only tens of femtograms of molecules inside the single nanoslot, can readily be detected. Our work enables terahertz sensing of chemical and biological molecules in ultrasmall quantities.
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IJS, KILJ, NUK, PNG, UL, UM
Differential cross sections as a function of transverse momentum pT are presented for the production of ϒ(nS) (n = 1, 2, 3) states decaying into a pair of muons. Data corresponding to an integrated ...luminosity of 4.9fb−1 in pp collisions at s=7TeV were collected with the CMS detector at the LHC. The analysis selects events with dimuon rapidity |y|<1.2 and dimuon transverse momentum in the range 10<pT<100GeV. The measurements show a transition from an exponential to a power-law behavior at pT≈20GeV for the three ϒ states. Above that transition, the ϒ(3S) spectrum is significantly harder than that of the ϒ(1S). The ratios of the ϒ(3S) and ϒ(2S) differential cross sections to the ϒ(1S) cross section show a rise as pT increases at low pT, then become flatter at higher pT.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•6Li(d,α)4He, 6Li(d,p)7Li, 6Li(d,p)7Li*, 7Li(d,α)5He, and 7Li(d,nα)4He reactions cross-sections at deuteron energies from 0.3 MeV to 2.2 MeV have been measured.•The data obtained allow us to estimate ...the average neutron energy.•The data obtained are important for many applications, including radiation testing of advanced materials and equipment.
The interaction of a deuteron beam with lithium is characterized by a high yield of neutrons, high energy of neutrons and a large variety of reactions. The reliable data of the reactions cross-sections are important for many applications, including radiation testing of advanced materials and equipment. The experimental data on the cross-sections differ greatly from one author to another; for a number of reactions there is no data on the cross-section in the databases. Measurements of the reactions cross-sections were carried out at the accelerator-based neutron source VITA at Budker Institute of Nuclear Physics (Novosibirsk, Russia) using an α-spectrometer. The 6Li(d,α)4He, 6Li(d,p)7Li, 6Li(d,p)7Li*, 7Li(d,α)5He, and 7Li(d,nα)4He reactions cross-sections at deuteron energies from 0.3 MeV to 2.2 MeV have been measured. The obtained data are presented tabular form.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A significant advance toward the design and fabrication of a novel hierarchical supercapacitor electrode consisting of FeCo2S4‐tubes with well‐defined square cross‐section and intersecting nanosheets ...built porous shells on a 3D porous Ni backbone via controlled sulfidation is reported. This general method allows template‐free synthesis of metal sulfides tubular structures with polygonal cross‐sections and also fine control over the nanostructure leading to both maximized porosity and saturation sulfidation. New insights into concentration and time dependent sulfidation reaction kinetics are proposed. The FeCo2S4 electrode achieves a specific capacitance reaching 2411 F g‐1 at 5 mA cm‐2 and good rate capability, which are superior over those for nanotube arrays of other ternary transition metal sulfides. This is attributed to rich redox reactions, the highly porous but robust architecture as well as high electrical conductivity. Especially such porous shells effectively avoid “dead volume”, thus improve the utilization ratio of the electrode material. Asymmetric solid‐state device applying the FeCo2S4 as positive electrode and N‐doped graphene hydrogel film as negative electrode has a high cell voltage of 1.6 V and thus delivers considerably higher energy density of 76.1 W h kg‐1 (at 755 W kg‐1) than those reported for similar devices.
General controlled sulfidation results in a novel hierarchical supercapacitor electrode consisting of FeCo2S4‐tubes with well‐defined square cross‐section and intersecting nanosheets built porous shells on a 3D porous Ni backbone, which shows high specific capacitances, good rate‐capability and excellent cycling‐stability due to the highly porous but robust architecture, rich redox reactions as well as high conductivity.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A new planar wideband chessboard structure is designed to reduce the radar cross-section (RCS) of an object. This proposed chessboard configuration is composed of two different artificial magnetic ...conductor (AMC) tiles. One of these tiles is formed by saltire arrow unit cells, whereas the other one is formed by four E-shaped ones. A 180° ± 30° phase difference between these tiles achieved by precise design of the AMC unit cells of more than 9.4–23.28 GHz (85%) reduces the RCS by more than 10 dB. The fabricated board results show very good agreement with the simulated ones, which verify the ability and capability of the proposed structure.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A new exact representation for the normalized Mott cross section is obtained. Some earlier exact and approximate methods for its calculation are compared with the method proposed in this work. It is ...demonstrated that applying the suggested rigorous method, along with the approximate method of Lijian et al., is most preferable for the above calculations. Some modifications of Lijian’s method are proposed. Based on these modifications and the Lijian method itself, new analytical expressions are obtained for the Mott corrections to the Bethe stopping formula and the primary displacement cross section by fast electrons. It is shown that the highest fitting accuracy of the displacement cross sections is provided by the twice modified Lijian method.
•A new exact representation for the normalized Mott cross section is proposed.•The modified and twice modified Lijian−Qing−Zhengming methods are suggested.•Based on these methods, a new analytical expression for Mott’s correction is obtained.•We also get in this way a new expression for the atomic displacement cross section.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Effective thermal and hydraulic parameters in MCHS are investigated.•Different patterns, cross-sections and manifolds of MCHS are analyzed.•PEC is calculated to select the best geometry as paper ...novelty.•Another novelty is commercialized MCHS that introduced and discussed.
With progress in technology and miniaturization of electronic devices, liquid coolants were used increasingly in personal computers, laptops, servers, and supercomputers. Micro heat sinks are widely used for cooling rate enhancement. Geometrical design plays a crucial role in the thermal performance of microchannel heat sinks. This work reviews the researches concerning micro heat sinks via three aspects: (1) Flow passage patterns, (2) Geometry of cross-sections (3) Inlet and outlet manifolds containing header shapes and the manifold position. Main specifications of each feature were tabulated to make it appropriate for comparisons. The main aims of this study are to cover the research gap in a review of cross-section impact on the thermo-hydraulic performance of microchannel heat sinks. Then summarize important data of articles in the table at the end of each section and extract data from some results of articles. Performance evaluation criteria (PEC) is calculated using extracted data to achieve better decision from the perspective of cross-section and pattern of the microchannel heat sink. Furthermore, the commercialized heat sinks for electronics cooling, which follow the outcomes of scientific reports were discussed which has not been reported before.
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Current stainless steel design standards are based on elastic, perfectly plastic material behaviour providing consistency with carbon steel design expressions, but often leading to overly ...conservative results, particularly in the case of stocky elements. More economic design rules in accordance with the actual material response of stainless steel, which shows a rounded stress–strain curve with significant strain hardening, are required. Hence, the continuous strength method (CSM) was developed. The CSM replaces the concept of cross-section classification with a cross-section deformation capacity and replaces the assumed elastic, perfectly plastic material model with one that allows for strain hardening. This paper summarises the evolution of the method and describes its recent simplified form, which is now suitable for code inclusion. Comparison of the predicted capacities with over 140 collected test results shows that the CSM offers improved accuracy and reduced scatter relative to the current design methods. The reliability of the approach has been demonstrated by statistical analyses and the CSM is currently under consideration for inclusion in European and North American design standards for stainless steel structures.
► Development of a new method for the design of stainless steel structures, known as the continuous strength method (CSM). ► Collection of stub column and beam test data from a broad spectrum of existing testing programs. ► Comparison of the predicted capacities with collected experimental results. ► Demonstration of the reliability of the approach by means of codified statistical analyses procedures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This work aims at the calculation of various inelastic cross sections for three pentane isomers, namely normal pentane, isopentane and neopentane. The direct ionisation, positronium formation, total ...ionisation and total inelastic cross section are reported for these targets using modified spherical complex optical potential (mSCOP) and complex scattering potential-ionisation contribution (CSP-ic) method. The cross sections are computed for a wide energy range from their respective thresholds to 5 keV. We have also attempted to probe the isomeric effect in the inelastic scattering of positrons from the pentane isomers. The cross sections for the three isomers were found to overlap for the entire comparative energy range except at the peak region. Hence, in general no appreciable isomeric effect was beheld for the pentane isomers.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
We employ the numerically exact superposition
T-matrix method to perform extensive computations of scattering and absorption properties of soot aggregates with varying state of compactness and size. ...The fractal dimension,
D
f, is used to quantify the geometrical mass dispersion of the clusters. The optical properties of soot aggregates for a given fractal dimension are complex functions of the refractive index of the material
m, the number of monomers
N
S, and the monomer radius
a. It is shown that for smaller values of
a, the absorption cross section tends to be relatively constant when
D
f<2 but increases rapidly when
D
f>2. However, a systematic reduction in light absorption with
D
f is observed for clusters with sufficiently large
N
S,
m, and
a. The scattering cross section and single-scattering albedo increase monotonically as fractals evolve from chain-like to more densely packed morphologies, which is a strong manifestation of the increasing importance of scattering interaction among spherules. Overall, the results for soot fractals differ profoundly from those calculated for the respective volume-equivalent soot spheres as well as for the respective external mixtures of soot monomers under the assumption that there are no electromagnetic interactions between the monomers. The climate-research implications of our results are discussed.
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