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Solid-state reaction at 1000 °C produces a series of Li-stuffed Li5+2x(La1-yEuy)3(Ta1-xZrx)2O12 garnet phosphors (x = 0-1, y = 0.05-0.6) that exhibit favorable efficiency and thermal stability for red luminescence under either blue or n-UV light excitation, where the optimal composition was identified to be x = 0.5 and y = 0.4. The concentration quenching of luminescence was determined to occur via electric dipole-dipole interactions. Zr4+ substitution for Ta5+, accompanied by additional Li+ for charge compensation, was found via Rietveld structure refinement and Raman/UV-Vis spectroscopy to profoundly affect the tetrahedral and octahedral occupancies of Li, the symmetry of (La/Eu)O8 dodecahedron, and the bandgap of the host lattice and cation disorder, with which the systematically varying excitation and emission behaviors of Eu3+ were deciphered. The Li6(La0.6Eu0.4)3(Ta0.5Zr0.5)2O12 optimal phosphor showed quantum yields of ∼40 and 48% under 393 and 463 nm excitations, respectively, a fluorescence lifetime of ∼0.66 ms for its main emission at 610 nm, color coordinates of around (0.653, 0.347), and can retain as high as ∼85% of its room-temperature emission intensity at 423 K. The phosphor also exhibited a favorable performance for n-UV excited LED lighting.

Systematic crystallization of KLn(MoO4)2 double molybdate micro/nanocrystals was achieved in this work for the family of lanthanide elements (excluding Pm) and Y via hydrothermal reaction under the optimized conditions of pH = 7, Mo/Ln molar ratio R = 5 and 200 °C, with which the intrinsic influence of lanthanide contraction on phase preference, crystallite morphology (size/shape) and crystal structure was clearly revealed. Extended synthesis also produced KLa1−xEux(MoO4)2 (KLM:xEu) and KY1−yEuy(MoO4)2 (KYM:yEu) red phosphors, and detailed spectral analysis found that the layered structure of orthorhombic KYM allows Eu3+ to have a high quenching content of ∼70 at% (y = 0.7) and higher quantum efficiency and thermal stability of luminescence. Application also indicated that the KYM:0.7Eu optimal phosphor has the potential for optical temperature sensing with the thermally coupled 5D0 and 5D1 energy levels of Eu3+.

The two-dimensional (2D) crystallite morphology and low OH−/Ln3+ molar ratio of Ln2(OH)4SO4·2H2O (Ln = lanthanide) make it an ideal precursor for materials synthesis via phase conversion, which was manifested in this work by the direct generation of well-defined NaLn(WO4)2 phosphor particles via hydrothermal reaction with Na2WO4. Kinetics study showed that pure NaLn(WO4)2 can be produced by reaction at 180 °C for ~24 h or at 200 °C for ~6 h under WO42−/Ln3+ = 10 M ratio. Morphology analysis revealed that, though NaLn(WO4)2 evolved via re-precipitation, the layered crystal structure and 2D crystallite morphology of the precursor could have templated the nucleation/growth of NaLn(WO4)2, leading to uniform particles (~4–5 μm) of a unique microdisc-like morphology. Under 394 nm excitation, the Ln = La0.95Eu0.05 phosphor showed down-conversion luminescence having an absolute quantum yield of ~35.4%, a fluorescence lifetime of ~1.13 ms for its 616 nm main emission, and color coordinates of around (0.63, 0.37). Under 978 nm laser excitation, the Ln = La0.97Yb0.02Ho0.01 and Ln = La0.97Yb0.02Er0.01 phosphors exhibited the strongest up-conversion (UC) luminescence at ~660 nm (the 5F5 → 5I8 transition of Ho3+) and 551 nm (the 4S3/2 → 4I15/2 transition of Er3+), average fluorescence lifetimes of ~178.3 and 82.3 µs for the above emissions, and chromaticity coordinates of around (0.62, 0.38) and (0.25, 0.72), respectively. The two UC phosphors were also analyzed to exhibit UC luminescence through a two-photon mechanism.

A series of garnet-structured Li6Ca(La0.99-xYbxEr0.01)2Nb2O12 (0≤x≤0.05) phosphors were originally synthesized and examined for upconversion (UC) luminescence and optical temperature sensing under 978 nm laser excitation. It was identified that the optimal content of Yb3+ sensitizer is x=0.04 for Er3+ emission and the non-thermally coupled 2H11/2/4F9/2 energy levels of Er3+ possess a superior capability of optical thermometry, whose maximum absolute sensitivity (~15.20 × 10−3 K−1 at 523 K) is generally ~1.7-6.1 times the values reported to date for most of other UC systems.

Systematic crystallization of KLn(MoO

Solid-state reaction at 1000 °C produces a series of Li-stuffed Li5+2x(La1-yEuy)3(Ta1-xZrx)2O12 garnet phosphors (x = 0-1, y = 0.05-0.6) that exhibit favorable efficiency and thermal stability for red luminescence under either blue or n-UV light excitation, where the optimal composition was identified to be x = 0.5 and y = 0.4. The concentration quenching of luminescence was determined to occur via electric dipole-dipole interactions. Zr4+ substitution for Ta5+, accompanied by additional Li+ for charge compensation, was found via Rietveld structure refinement and Raman/UV-Vis spectroscopy to profoundly affect the tetrahedral and octahedral occupancies of Li, the symmetry of (La/Eu)O8 dodecahedron, and the bandgap of the host lattice and cation disorder, with which the systematically varying excitation and emission behaviors of Eu3+ were deciphered. The Li6(La0.6Eu0.4)3(Ta0.5Zr0.5)2O12 optimal phosphor showed quantum yields of ∼40 and 48% under 393 and 463 nm excitations, respectively, a fluorescence lifetime of ∼0.66 ms for its main emission at 610 nm, color coordinates of around (0.653, 0.347), and can retain as high as ∼85% of its room-temperature emission intensity at 423 K. The phosphor also exhibited a favorable performance for n-UV excited LED lighting.

According to the basic structure model of speech recognition system, this paper introduces the basic technology of digital signal processing and pattern recognition involved in preprocessing, feature parameter extraction and model matching. Using feature parameter extraction, forced association and dynamic time warping, speech scoring based on feature comparison and HMM is studied respectively. At the same time, Viterbi alignment algorithm, process pruning and model storage optimization are also improved, which makes the speed of speech recognition in the platform faster and it provides users better response. Finally, the performance and accuracy of the system are tested compared with the scoring algorithm based on continuous hidden Markov model. The experiment results show that the recognition speed is significantly improved. The model can basically reflect the learners' English pronunciation level, correct most of the learners' errors, and it is helpful to the training of English pronunciation level.

This paper focuses on the research of diversified e-commerce activities in e-commerce platform, mapping various business activities into the framework of resource allocation. When a certain number of users access the platform concurrently, the system allocates resources. This paper abandons the traditional simple filtering mode to analyze the historical data of e-commerce platform, abstracts the user commodity binary network and divides the user communities according to the attribute information of users and commodities and the purchase logs of users. By analyzing the community of users, we can allocate resources reasonably. In the binary network of users and goods, there are still many problems in user based clustering. For example, the sparseness of user attribute information, the proportion of intersection between users' purchasing goods is too small and so on. According to the characteristics of data and the existing problems, this paper selects the SimRank algorithm and improves it. In this paper, a combined similarity index based on user attributes and network structure is proposed to improve the accuracy of user clustering, and a reasonable scheme of resource allocation is proposed by using the community division of users, which increases the accuracy of user clustering, achieves the expected design goals, and improves work efficiency.

Assigning virtual machines to appropriate physical machines has becoming a hot issue in the field of cloud computing. This paper combines ant colony optimization algorithm with virtual machine scheduling idea, and proposes a virtual machine scheduling algorithm based on ant colony model. By analyzing the historical memory consumption of each physical machine, the algorithm can predict the future memory consumption of each physical machine, thus realizing the effective allocation of virtual machine resources on cloud infrastructure. In order to verify the effectiveness of the proposed algorithm, simulation experiments are carried out under homogeneous and heterogeneous modes with the current representative algorithms, respectively. The results show that the proposed algorithm has remarked supercities.

A series of garnet-type Li6CaLa2(1-x)Nb2O12:xRE phosphors (LCLN:xRE, RE = Pr, Sm, Tb and Dy) were prepared via sol-gel processing and subsequent calcination for the first time, with the course of phase evolution and the characteristics of the LCLN host and RE3+ luminescence being investigated in detail. It was found that ∼900–1000 °C is a suitable temperature for precursor calcination to produce the garnet phase and LCLN has a relatively low phonon energy (∼725 cm−1) and a relatively wide bandgap (∼4.53 eV) for luminescence. The LCLN:0.012Pr, LCLN:0.04Sm, LCLN:0.06 Tb and LCLN:0.06Dy typical phosphors were analyzed to have dominant excitation/emission bands at ∼278/489, 265/614, 268/549 and 264/581 nm, emission colors of white, orange, green and yellowish white, and fluorescence lifetimes of ∼0.43, 0.74, 0.90 and 0.44 ms, respectively. Temperature-dependent photoluminescence found that the four phosphors maintained ∼28, 37, 45 and 56% of their room-temperature intensities at 423 K, with activation energies for thermal quenching of ∼0.37, 0.29, 0.34 and 0.25 eV, respectively. The results demonstrated that the Li-stuffed LCLN garnet could be a suitable host for UV excitable multicolor phosphors.

Sc 2 O 3 -Y 2 O 3 solid solution (SYSS) ceramics with novel nanocrystalline structures have been successfully fabricated by spark plasma sintering (SPS) method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR and indentation techniques. The SYSS ceramics can possess high hardness by keeping their excellent infrared transmission performance. Especially, the transmittance of as-obtained SYSS ceramics can exceed as high as 80% in the infrared region of 2–6 µm. Moreover, the Vickers hardness is increased to 9.18 GPa by increasing the addition ratio of Sc 2 O 3 to 20 at%. Here, it is very important to point out that the mechanical strength of yttria ceramics can be evidently enhanced without deteriorating their optical transmission performance by the addition of Sc 2 O 3 as well as the application of SPS technique, where the solid solution strengthening and fine grain strengthening are involved during the synthesis process, respectively.

To improve the level of automation and intelligence of English language transformation in machine translation, a method of machine translation error elimination based on deep learning and feature extraction of language transformation error is proposed. The semantic correlation detection model of error exclusion in English language conversion translation is constructed by using the differentiated semantic modification method, and the semantic tree of error exclusion in English language transformation translation is built by means of grammar analysis. The semantic similarity feature of English language transformation is extracted. According to the different combinations of semantic similarity, the semantic allocation and machine translation error feature analysis in English language transformation are carried out. The tree topic word list of English language conversion is established by means of deep learning method, and the sentence structure of English language transformation is adjusted according to the semantic modification target in the tree topic word list. In order to eliminate the errors in translation of English language conversion and the registration of topic words, the optimal semantic correlation feature of each clause is calculated, and the deep learning algorithm is used to automatically optimize the errors in translation of English language conversion. The simulation results show that the accuracy of the proposed approach is high and the relevance of translation calibration is strong.

In a wireless sensor network, the signal received by the terminal processor is usually a complex single channel hybrid chaotic signal. The engineering needs to separate the useful signal from the mixed signal to perform the next transmission analysis. Since chaotic signals are nonlinear and unpredictable, traditional blind separation algorithms cannot effectively separate chaotic signals. Aiming to correct these problems—based on the particle filter estimation algorithm—an extended Kalman particle filter algorithm (EPF) and an unscented Kalman particle filter algorithm (UPF) are proposed to solve the single channel blind separation problem of chaotic signals. Mixing chaotic signals of different intensities performs blind source separation. Using different evaluation indexes carries out the experiment and performance can be analyzed. The results show that the proposed algorithm effectively separates the mixed chaotic signals.

The parameter estimation of communication signal is a key problem in noncooperative communication signal processing. The traditional algorithm which uses cyclic spectrum to estimate signal's parameters could not achieve the desired results in alpha-stable distribution noise environment. Therefore, in this paper, a joint estimation algorithm based on the generalized cyclic spectrum is proposed. Firstly, this paper defines the generalized cyclic spectrum through the nonlinear transformation. Then the carrier frequency and the symbol rate are estimated by detecting spectral peak of different sections of the generalized cyclic spectrum. In the end, the algorithm is simulated by the BPSK modulation signal, and the experimental results are analyzed with the normalized mean square error and the deviation. Compared with the performance of the traditional cyclic spectrum algorithm in Gaussian noise, it can be seen that the joint estimation algorithm is feasible in alpha-stable distribution noise.

Rheological experiments of cetyltrimethylammonium salicylate (C16TASal) solution were carried out on the micellar solutions as a function of surfactant concentration and temperature. This system forms short, rod-like micelles at concentrations of 1–15% as determined by transmission electron microscopy. Rheological behavior at low concentration displays gel-like behavior up to 3%, while it follows Maxwell fluid behavior with a single stress relaxation time above 3%. By the single crystal diffraction experiment, it can be found that the gel-like and Maxwell-like viscoelasticities originate in a three-dimensional network formed by hydrogen bond linkages between short rod-like micelles, connecting carboxyl groups of salicylate anions and water molecules. The high viscosity is from the linkages between short rod-like micelles rather than from entangled long micelles. The electronic conductivities of C16TASal solution of dilute solution and semi-dilute solution have been studied. The conductivity–concentration curves of dilute solution show two breaks which correspond to two characteristic concentrations of C16TASal solution. The first break point corresponds to the critical micelle concentration (cmc). The second break point corresponds to the transition concentration (Ct), where the system begins to form rod-like micelles. The conductivity of semi-dilute solution slightly decreases with the increasing temperature.

Li6CaLa2Nb2O12 garnet is known as an electrolyte for Li+-batteries. The sol–gel processing of this work yielded a series of phase pure Li6CaLa2(1−x)Nb2O12:xEu3+ garnet phosphors (LCLNG:xEu; x = 0–0.40) that are efficiently excitable with either near-ultraviolet (NUV, ~350–400 nm) or blue (~450–475 nm) light to produce dominantly strong 610 nm red emission. Increasing Eu3+ substitution for La3+ (larger x) led to smaller cell constant and lower symmetry of the (La/Ca)O8 dodecahedron, as revealed via Rietveld structure refinement, and meanwhile narrower bandgap. The excitation/emission behaviors and high quenching concentration of Eu3+ (x = 0.35) were interpreted for the phosphor series by considering bandgap energy, (La/Ca)O8 distortion and local arrangement of atoms. The LCLNG:0.35Eu optimal phosphor was analyzed to have absolute quantum yields of ~51% (λex = 393 nm) and 65% (λex = 463 nm), fluorescence lifetime of ~0.70 ms and color coordinates of around (0.65, 0.35) at room temperature and to be able to retain as high as ~85% of its room-temperature intensity at 423 K for the 610 nm emission. Application of LCLNG:0.35Eu further indicated that this phosphor has the potential to be used in NUV-excited LEDs.

The phase behavior and microstructures of the aqueous two-phase systems (ATPS) composed of a cationic/an anionic surfactant (3-p-nonylphenoxy-2-hydroxypropyltrimethylammonium bromide, NPTAB/sodium dodecylbenzenesulfonate, SDBS) and an ionic liquid (1-hexyl-3-methylimidazolium tetrafluoroborate, [Hmim][BF4]) were studied by using cryogenic transmission electron microscopy (Cryo-TEM) observations, nuclear magnetic resonance (NMR) experiments and electric conductivity. The concentration effects of the surfactants and the ionic liquid on the phase separation were systematically investigated. The experimental outcomes indicated that the formation of ATPS can be attributed to the coexistence of different micelles in the upper and lower phases. The ATPS here investigated were further characterized for the first time through their application to the extractive potential for amino acids, where l -tryptophan was selected as a model biomolecule.

In recent years, the research on implantable medical devices has become a hot scientific topic, and the power supply of these devices are especially concerned. Generally, these devices are usually powered by disposable batteries. However, for some of the long-term human implant devices, such as pacemakers, once the battery has been exhausted after several years, the patient has to replace the battery by surgery, which increases the patient's economic burden and pain. Wireless power transfer technology, using non-contact way for power transfer, can be a good solution to this problem. In this paper, a micro induction coil was designed, and the transfer efficiency in the air and human tissue model of two-layers were simulated by Ansoft HFSS. The results showed that the system could achieve the energy transfer in both cases, meanwhile, it indicated that the transfer efficiency was lower in a relative larger permittivity of transmission medium.

CPA audit is a very important but comparative difficult content of the professional courses in the CPA teaching orientation in Accounting major. At present, in the professional teaching process of CPA, what has been instructed is the audit related theories with the teacher as the class subject and students passively as the knowledge receiver. Also, the specific teaching methods are very limited. Teachers pay attention to blindly instilling knowledge and the teaching procedure of examples in the class has been restrained in partial aspects of auditing. This kind of teaching method has prevented the students' learning initiative and motivation to be developed so that their own abilities cannot be improved. Therefore, traditional teaching methods should be reformed and innovated by actively using task-driven teaching method so as to promote the realization of teaching objectives of CPA audit.

Aqueous two-phase systems (ATPS) were obtained in the aqueous mixtures of a cationic surfactant and a series of ionic liquids (ILs). The effects of IL structure, temperature and additives on the phase separation were systematically investigated. The microstructures of some ATPS were observed by freeze-fracture replication technique. Lyotropic liquid crystal was found in the bottom phase besides micelles under different conditions. Remarkably, both IL structure and additives profoundly affected the formation and properties of the ATPSs. The phase separation can be attributed to the existence of different aggregates and the cation-π interactions of the cationic surfactant with the ILs, which has a significant role in the formation of ATPS. The extraction capacity of the studied ATPS was also evaluated through their application in the extraction of two biosubstances. The results indicate that the ILs with BF 4 − as anion show much better extraction efficiencies than the corresponding ILs with Br − as anion do under the same conditions. l -Tryptophan was mainly distributed into the NPTAB-rich phase, while methylene blue and capsochrome were mainly in the IL-rich phase.

Hypertension, as one of diseases with the highest incidence in the world at present, is an important cause of stroke, coronary heart disease, renal insufficiency and other serious diseases. Based on pseudo Wigner-Ville distribution, this paper makes an analysis on the relevant pulse characteristics by measuring time range of the energy concentration circle. In view of the present situation, that is, about half of the high-normal blood pressure persons are likely to develop hypertension, we explored the pulse characteristics to find the pathological changes in subjects with prehypertension, in order to solve the problems that there are no obvious clinical significant features in prehypertension. The results showed that the duration of high energy circle in signal with hypertension pathological changes was shorter than the duration of healthy signal. Hence, healthy signal and hypertension pathological signal can be effectively distinguished by this method, and this provides a new basis to identify the lesion signal when blood pressure is in critical period.

This paper carries out the multi-scale decomposition of pulse signals on different frequency bands by wavelet transform, and the analysis of power spectral density shows that the detailed signal energy of the fourth layer mainly concentrates on the 3-5 Hz, while the energy of the fifth layer concentrating on the 1-3 Hz. Through calculating the energy, the experimental results show that: the hypertension signal energy of 3-5 Hz band increases significantly, compared with the normal signals.