A DFT study of sulforaphane adsorption on the group III nitrides (B12N12, Al12N12 and Ga12N12) nanocages.

In this paper, the adsorption behavior of group III nitrides (B12N12, Al12N12, and Ga12N12) nanocages to sulforaphane (SF) anticancer medicine were studied by density functional theory (DFT). The adsorption energy, solvation energy, desorption time and related quantum molecular descriptors were calculated in neutral and acidic solutions. When the drugs were adsorbed to nanocages, the structure of nanocages and drugs changed after adsorption, indicating that the process was effective adsorption.

Time-bin phase-encoding quantum key distribution using Sagnac-based optics and compatible electronics.

In this work, we present a new time-bin phase-encoding quantum key distribution (QKD), where the transmitter utilizes an inherently stable Sagnac-type interferometer, and has comparable electrical requirements to existing polarization or phase encoding schemes. This approach does not require intensity calibration and is insensitive to environmental disturbances, making it both flexible and high-performing. We conducted experiments with a compact QKD system to demonstrate the stability and secure key rate performance of the presented scheme.

Field test of quantum key distribution over aerial fiber based on simple and stable modulation.

We have developed a simple time-bin phase encoding quantum key distribution system, using the optical injection locking technique. This setup incorporates both the merits of simplicity and stability in encoding, and immunity to channel disturbance. We have demonstrated the field implementation of quantum key distribution over long-distance deployed aerial fiber automatically.

Effect of hydrostatic pressure on the structural, elastic, and optoelectronic properties of vacancy-ordered double perovskite CsPdBr.

The vacancy-ordered double perovskite CsPdBr has the advantages of good optoelectronic properties, environmental friendliness, and high stability. It has been experimentally confirmed by researchers as an optoelectronic material with broad application prospects and research value, and is regarded as a potential substitute for lead halide perovskites. In this paper, based on the first-principles calculations in the framework of density functional theory, the crystal structure, elastic, electronic, and optical properties of CsPdBr under hydrostatic pressure of 0-6 GPa have been investigated with a step size of 0.

Theoretical exploration of mechanical, electronic structure and optical properties of aluminium based double halide perovskite.

The mechanical, electronic structure and optical properties of aluminium based double halide perovskite were calculated by density functional theory. The formation energy and elastic constant confirm the stability of the cubic perovskite materials. The materials are all ductile and suitable for flexible photovoltaic and optoelectronic devices.

Theoretical Study on the Carrier Mobility and Optical Properties of CsPbI by DFT.

The advantages of organic-inorganic hybrid halide perovskites and related materials, such as high absorption coefficient, appropriate band gap, excellent carrier mobility, and long carrier life, provide the possibility for the preparation of low-cost and high-efficiency solar cell materials. Among the inorganic materials, CsPbI is paid more attention to by researchers as CsPbI has incomparable advantages. In this paper, based on density functional theory (DFT), we first analyze the crystal structure, electronic properties, and work function of two common bulk structures of CsPbI and their slices, and then, we study the carrier mobility, exciton binding energy, and light absorption coefficient.

Study on the properties of perovskite materials under light and different temperatures and electric fields based on DFT.

The photoelectric conversion efficiency of perovskite solar cells has improved rapidly, but their stability is poor, which is an important factor that restricts their commercial production. This paper studies the physical and chemical stability of perovskite solar cells based on first principles. It is well known that methylamido lead iodide compounds and methylamino lead iodide compounds are easily degraded into NHCH[double bond, length as m-dash]NHI, CHNHI and PbI.

Long-distance transmission of quantum key distribution coexisting with classical optical communication over a weakly-coupled few-mode fiber.

Quantum key distribution (QKD) is one of the most practical applications in quantum information processing, which can generate information-theoretical secure keys between remote parties. With the help of the wavelength-division multiplexing technique, QKD has been integrated with the classical optical communication networks. The wavelength-division multiplexing can be further improved by the mode-wavelength dual multiplexing technique with few-mode fiber (FMF), which has additional modal isolation and large effective core area of mode, and particularly is practical in fabrication and splicing technology compared with the multi-core fiber.

Study on the Property of Electron-Transport Layer in the Doped Formamidinium Lead Iodide Perovskite Based on DFT.

The electron-transport layer in planar perovskite solar cells plays an important role in improving photoelectric conversion efficiency. At present, the main electronic transmission materials in perovskite solar cells include TiO, ZnO, WO, ZrO, SnO, ZnO, etc. This work mainly studies the electron-transport characteristics of six different electron-transport layers in perovskite solar cells.

Identification of tea based on CARS-SWR variable optimization of visible/near-infrared spectrum.

Background: The identification of tea varieties is essential to obtain high-quality tea that can command a high price. To identify tea varieties quickly and non-destructively, and to fight against counterfeit and inferior products in the tea market, a new method of visible / near-infrared spectrum processing based on competitive adaptive reweighting algorithms-stepwise regression analysis (CARS-SWR) variable optimization is proposed in this paper.

Results: The spectral data of five different tea varieties were obtained by visible / near-infrared spectrometry.

[Study on the frontier orbital and Raman spectra of Aflatoxin B1 and isomer].

Through computation, this paper obtained Aflatoxin B1 and its trans-isomer molecules stable structure which was rarely reported by the density functional theory(DFT) with B3LYP complex function and 6-311 + g(d, p) basis set. Through a single point calculations and geometry analysis, we know that the cis-structure is more stable than trans-structure. On the basis of this, Raman spectra of two molecules are calculated by the same method and basis set.

Measurement-device-independent quantum key distribution over 200 km.

Measurement-device-independent quantum key distribution (MDIQKD) protocol is immune to all attacks on detection and guarantees the information-theoretical security even with imperfect single-photon detectors. Recently, several proof-of-principle demonstrations of MDIQKD have been achieved. Those experiments, although novel, are implemented through limited distance with a key rate less than 0.

[The self intensification of the pure spectrum in the mixed spectrum].

In the present paper, the influence of the pure spectrum contained in the mixed spectrum was centralized at the origin, and in this way, the influence of the pure spectrum in the result curve reached the maximum value. This process is called the self intensification of the pure spectrum. Farther, considering that the center of the Gaussian function contained in the impure spectrum is much different from that of the pure spectrum, it can be accepted that the influence of the impure spectrum at the origin is approximately the minimum.

[Prediction of total nitrogen in flue-cured tobacco with UV spectrometry].

Ultraviolet (UV) spectrum method was used to measure the spectra of flue-cured tobacco, and the spectra of different grades of flue-cured tobacco were compared. The samples were scanned in 210-360 nm with UV spectrometer. Further, the UV predicting models of total nitrogen of tobacco leaves were established by stepwise multiple regression method, principal components analytic method and partial least squares method.

Nitrogen contents of rice panicle and paddy by hyperspectral remote sensing.

The nitrogen content or crude protein content in rice grains is one of the important indices to evaluate the nutrition and taste quality of rice. Normal determination of their contents by chemical methods is highly expensive and time consuming. The hyperspectral reflectances of the canopy, flag leaf and panicle of 5 rice varieties are measured by a ASD FieldSpec Pro FR in field under 3 nitrogen support levels in maturing process.

[Estimation of rice LAI by using NDVI at different spectral bandwidths].

The canopy hyperspectral reflectance data of rice at its different development stages were collected from field measurement, and the corresponding NDVIs as well as the correlation coefficients of NDVIs and LAI were computed at extending bandwidth of TM red and near-infrared (NIR) spectra. According to the variation characteristics of best fitted R2 with spectral bandwidth, the optimal bandwidth was determined. The results showed that the correlation coefficients of LAI and ND-VI and the maximum R2 of the best fitted functions at different spectral bandwidths had the same variation trend, i.