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Leptin receptor‐positive skeletal progenitors constitute an essential cell population in the bone, yet their heterogeneity remains incompletely understood. In this issue, Mo et al (2021) report a single‐cell RNA sequencing resource that deconvolutes the pool of LEPR+ skeletal cells under homeostatic and various pathologic conditions, uncovering context‐dependent contributions to diverse cell types and functions. [ABSTRACT FROM AUTHOR]

Green and economical self-doped nitrogen-containing fluorescent carbon quantum dots (N-CQDs) were synthesized using a one-pot hydrothermal treatment method. The optical and structural properties of the N-CQDs were investigated in detail by UV-vis and fluorescence spectroscopy, X-ray diffraction (XRD) techniques, transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) spectroscopy, and elemental analysis illustrate the surface function and composition of N-CQDs. N-CQDs emit a broad fluorescence between365 ̴ 465 nm and fluoresce most strongly at the excitation wavelength of 415 nm. Meanwhile, Cr (VI) could significantly burst the fluorescence intensity of N-CQDs. N-CQDs showed an excellent sensitivity and selectivity to Cr (VI), which exhibited good linearity in the range of 0 ̴ 40 µmol/L with a detection limit of 0.16 µmol/L. In addition, the mechanism of Fluorescence quenching of N-CQDs by Cr (VI) was investigated. This work well provides a research idea for the preparation of green carbon quantum dots from biomass and their use for the detection of metal ions. [ABSTRACT FROM AUTHOR]

Backgrounds: Persistent trigeminal artery (PTA) is a rare anastomosis between internal carotid artery (ICA) and basilar artery. In rare conditions, the PTA could be combined with others cerebrovascular anomalies, moyamoya disease (MMD) is one of them. Case presentation: Here, we reported one rare case of MMD associated with PTA, the patient admitted to our department for severe dizziness and headache, imaging examination suggested MMD combined with right PTA, which arising from the ipsilateral cavernous portion of ICA. The patient received phased bilaterral revascularization with no any complication. In the subsequent follow-up, the patient's symptoms and intracranial vascular condition gradually improved. Moreover, we conducted a literature review of coexistence of PTA and MMD, the results of a web of science regarding such condition, and a deep discussion providing brief insight into the status of co-occurrence of PTA and MMD, including its manifestation, treatment and outcome. Conclusions: The coexistence of PTA and MMD was rarely reported, the pathogenesis of such condition remains unknown. We found that the features of the coexistence of PTA and MMD were diverse, revascularization might be a feasible for such patient. [ABSTRACT FROM AUTHOR]

Two new hexa-Ni-substituted polyoxometalates (POMs), [Ni6(μ3-OH)3(en)2(dien)(H2O)5(B-α-PW9O34)]·3H2O (1, en = ethylenediamine, dien = diethylenetriamine) and [Ni6(μ3-OH)3(dap)2(py)6(H2O)(B-α-PW9O34)]·H2O (2, dap = 1,3-diaminopropane, py = pyridine), were successfully isolated under hydrothermal conditions. Compounds 1 and 2 were structurally characterized via single-crystal X-ray diffraction (XRD), infrared (IR) spectrometry, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Single-crystal X-ray structure analyses indicate that the {Ni6PW9} cluster units were modified via different organic ligands through Ni–N bonds, giving rise to the formation of 1 and 2. Interestingly, the formation of 1 involves new in situ ligand reactions under hydrothermal conditions: the intermolecular deamination coupling reactions of en. Compound 2 is a new Z-shaped 1-D chain, which is connected by Ni–O＝W bonds from two adjacent [Ni6(μ3-OH)3(dap)2(py)6(H2O)(B-α-PW9O34)] units. In addition, their photocatalytic activities, and electrochemical and magnetic properties have been investigated. [ABSTRACT FROM AUTHOR]

This paper proposes the shrink Gaussian distribution quantum-behaved optimization (SG-QPSO) algorithm to solve economic dispatch (ED) problems from the power systems area. By shrinking the Gaussian probability distribution near the learning inclination point of each particle iteratively, SG-QPSO maintains a strong global search capability at the beginning and strengthen its local search capability gradually. In this way, SG-QPSO improves the weak local search ability of QPSO and meets the needs of solving the ED optimization problem at different stages. The performance of the SG-QPSO algorithm was obtained by evaluating three different power systems containing many nonlinear features such as the ramp rate limits, prohibited operating zones, and nonsmooth cost functions and compared with other existing optimization algorithms in terms of solution quality, convergence, and robustness. Experimental results show that the SG-QPSO algorithm outperforms any other evaluated optimization algorithms in solving ED problems. [ABSTRACT FROM AUTHOR]

This paper proposes the shrink Gaussian distribution quantum-behaved optimization (SG-QPSO) algorithm to solve economic dispatch (ED) problems from the power systems area. By shrinking the Gaussian probability distribution near the learning inclination point of each particle iteratively, SG-QPSO maintains a strong global search capability at the beginning and strengthen its local search capability gradually. In this way, SG-QPSO improves the weak local search ability of QPSO and meets the needs of solving the ED optimization problem at different stages. The performance of the SG-QPSO algorithm was obtained by evaluating three different power systems containing many nonlinear features such as the ramp rate limits, prohibited operating zones, and nonsmooth cost functions and compared with other existing optimization algorithms in terms of solution quality, convergence, and robustness. Experimental results show that the SG-QPSO algorithm outperforms any other evaluated optimization algorithms in solving ED problems. [ABSTRACT FROM AUTHOR]

Although O-arm–based navigation (ON) has been considered a better choice than the conventional freehand (FH) technique for spine surgery, clinical evidence showing the accuracy of ON compared with the FH technique is limited. The purpose of this study was to evaluate the accuracy of pedicle screw insertion under ON compared with the FH technique. The Cochrane Library, Ovid, Web of Science, PubMed, Embase, and CNKI online databases were searched up to January 2020. Because only a few randomized controlled trials were anticipated, prospective and retrospective comparative studies were also evaluated to compare the accuracy of pedicle screw insertion between ON and FH. Statistical analysis was performed using Stata 16.0. The primary outcomes extracted from articles that met the selection criteria were expressed as odds ratios for dichotomous outcomes with a 95% confidence interval. A χ2 test and I 2 statistics were used to evaluate heterogeneity. A total of 20 reviews were included in this meta-analysis without identifying additional studies from the references of published articles. These reviews included 1422 patients and 9982 screws. ON was used to insert 4797 pedicle screws and 5185 pedicle screws were inserted using the conventional FH technique with C-arm assistance. The meta-analysis showed that ON is significantly more accurate than FH pedicle screw insertion (odds ratio, 2.46; 95% confidence interval, 1.92–3.16; I 2 = 43.4%; P = 0.021). I 2 indicates that the studies have a moderate statistical heterogeneity; subgroup analysis decreased heterogeneity significantly. Compared with conventional methods, navigation provides greater accuracy in the placement of pedicle screws, accelerates the insertion, and reduces the complications associated with screw insertion. However, it may increase exposure time to radiation, which may harm the patient's or surgeon's health. [ABSTRACT FROM AUTHOR]

Understanding the scaling between leaf size and leafing intensity (leaf number per stem size) is crucial for comprehending theories about the leaf costs and benefits in the leaf size–twig size spectrum. However, the scaling scope of leaf size versus leafing intensity changes along the twig leaf size variation in different leaf habit species remains elusive. Here, we hypothesize that the numerical value of scaling exponent for leaf mass versus leafing intensity in twig is governed by the minimum leaf mass versus maximum leaf mass (Mmin versus Mmax) and constrained to be ≤−1.0. We tested this hypothesis by analyzing the twigs of 123 species datasets compiled in the subtropical mountain forest. The standardized major axis regression (SMA) analyses showed the Mmin scaled as the 1.19 power of Mmax and the ‐α (−1.19) were not statistically different from the exponents of Mmin versus leafing intensity in whole data. Across leaf habit groups, the Mmax scaled negatively and isometrically with respect to leafing intensity. The pooled data's scaling exponents ranged from −1.14 to −0.96 for Mmin and Mmax versus the leafing intensity based on stem volume (LIV). In the case of Mmin and Mmax versus the leafing intensity based on stem mass (LIM), the scaling exponents ranged from −1.24 to −1.04. Our hypothesis successfully predicts that the scaling relationship between leaf mass and leafing intensity is constrained to be ≤−1.0. More importantly, the lower limit to scaling of leaf mass and leafing intensity may be closely correlated with Mmin versus Mmax. Besides, constrained by the maximum leaf mass expansion, the broad scope range between leaf size and number may be insensitive to leaf habit groups in subtropical mountain forest. [ABSTRACT FROM AUTHOR]

In current researches on the lubrication of engine piston ring, some were based on a hypothesis that the piston ring is on a flooded lubrication status. Although some others belong to the starved lubrication analysis, the one‐dimensional model, a certain form of starved lubrication status or simplified manner were used. In this paper, on the basis of the equations about the lubricating oil flow‐rate and control volume, a flow model of lubricating oil in the piston ring‐cylinder liner conjunction is established, and the influence of the situation of supplied lubricating oil film at the piston ring inlet on the two‐dimensional starved lubrication characteristics of piston ring for a four‐stroke engine is studied. The results indicate that the lubrication condition at the piston ring inlet has significant impact on the lubrication characteristics of piston ring. When the supplied lubricating oil at the piston ring inlet increases, the minimum film thickness of piston ring will increase, meanwhile the maximum film pressure, asperity contact force, friction force and power loss will decrease. If the film thickness at the piston ring inlet is smaller, the increase of the supplied film thickness can improve obviously the lubrication characteristics of piston ring. [ABSTRACT FROM AUTHOR]

PREMISE: Leaves are traditionally classified into microphylls and megaphylls, and recently have been regarded as independently originating in lycophytes, ferns, and seed plants. The developmental genetics of leaf dorsoventrality, a synapomorphy in vascular plants, has been extensively studied in flowering plants. AUXIN RESPONSE FACTOR4 (ARF4) genes are key to leaf abaxial identity in flowering plants, but whether they exist in ferns is still an open question. METHODS: ARF4 genes from Ceratopteris pteridoides, Cyrtomium guizhouense, and Parathelypteris nipponica were mined from transcriptomes and investigated in terms of evolutionary phylogeny and sequence motifs, with a focus on the tasiR‐ARF binding site. In situ hybridization was used to localize expression of CpARF4 in Ceratopteris pteridoides. 5′RNA ligase‐mediated‐RACE was employed to verify whether CpARF4 transcripts were sliced by tasiR‐ARF. RESULTS: ARF4 genes exist in ferns, and this lineage originates from a gene duplication in the common ancestor of ferns and seed plants. ARF4 genes are of a single copy in the ferns studied here, and they contain divergent and, at most, one tasiR‐ARF binding site. CpARF4 is expressed in the abaxial but not the adaxial domain of leaf primordia at various developmental stages. Transcript slicing guided by tasiR‐ARF is active in C. pteridoides, but CpARF4 probably has not been affected by it. CONCLUSIONS: Fern ARF4 genes differ in copy number and tasiR‐ARF regulation relative to flowering plants, though they can be similarly expressed in the abaxial domain of leaves, revealing a key role for ARF4 genes in the evolution of leaf dorsoventrality of vascular plants. [ABSTRACT FROM AUTHOR]

Although intensive efforts have been devoted to investigating latent tuberculosis (LTB) and active tuberculosis (PTB) infections, the similarities and differences in the host responses to these two closely associated stages remain elusive, probably due to the difficulty in identifying informative genes related to LTB using traditional methods. Herein, we developed a framework known as the consistently differential expression network to identify tuberculosis (TB)-related gene pairs by combining microarray profiles and protein–protein interactions. We thus obtained 774 and 693 pairs corresponding to the PTB and LTB stages, respectively. The PTB-specific genes showed higher expression values and fold-changes than the LTB-specific genes. Furthermore, the PTB-related pairs generally had higher expression correlations and would be more activated compared to their LTB-related counterparts. The module analysis implied that the detected gene pairs tended to cluster in the topological and functional modules. Functional analysis indicated that the LTB- and PTB-specific genes were enriched in different pathways and had remarkably different locations in the NF-κB signaling pathway. Finally, we showed that the identified genes and gene pairs had the potential to distinguish TB patients in different disease stages and could be considered as drug targets for the specific treatment of patients with LTB or PTB. [ABSTRACT FROM AUTHOR]

Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplastic disease associated with mutations in the gene encoding the Runt-related transcription factor 2 (RUNX2). CCD is characterized by hypoplastic clavicles and patent cranial sutures. Management is essential to prevent complications during growth of the patient. Herein, we report a sporadic case of an infant with hypoplastic skull and clavicles at birth, which correlated with clinical findings of CCD. A heterozygous mutation was identified in the RUNX2 gene, which confirmed the diagnosis of CCD. [ABSTRACT FROM AUTHOR]

Background: Primary hepatic sarcomatous carcinoma (PHSC) and primary hepatic sarcoma (PHS) are rare malignancies with frequent overlap in both the clinic and radiology. No comparative study of these tumors for the restricted cases has previously been undertaken. The purpose of our study was to analyze the clinical and imaging features of PHSCs and PHSs, with an emphasis on particularities and similarities through a comparison of the two tumors.Methods: We retrospectively analyzed the clinical and imaging features of 39 patients with pathologically proven PHSCs (n = 23) and PHSs (n = 16) from four university centers over a 9-year period from 2010 to 2019. Univariate analyses were performed to determine the consistent and distinctive features.Results: The background of chronic hepatitis or cirrhosis was observed with a high frequency in both of PHSCs (73.7%) and PHSs (62.5%). Tumors with a diameter greater than 10 cm were significantly more common in PHSs than PHSCs (p = 0.043) and cystic masses were more detected in PHSs (P = 0.041). Both PHSCs and PHSs mainly presented hypovascularity (78.3% vs 81.3%). The ring hyper enhancement on the arterial phase (AP) and wash out were more frequently seen in PHSCs and the iso-hypo enhancement on the AP followed persistent or progressive enhancement was more commonly detected in PHSs (all, p < 0.05).Conclusion: PHSC and PHS generally present as mass lesions with hypovascularity. The ring hyper enhancement on the AP and wash out favor the diagnosis of PHSC. The large size greater than 10 cm, cystic lesion, iso-hypo persistent or progressive enhancement pattern might suggest the possibility of PHSs. [ABSTRACT FROM AUTHOR]

Relativistic backward wave oscillator (RBWO) is a promising high-power microwave (HPM) generator. In past decades, many efforts have been devoted to improving its practicality, in which the repetitively operating RBWO has drawn much attention. However, two bottlenecks once limited its development. One is the generation of massive anode plasmas or even damage of the collector, and the other is the RF breakdown of electrodynamic structures. This article describes an RBWO which can operate repetitively with 3-GW microwave power by mitigating these two problems. First, a titanium collector, which shows better performance in resisting electron beam bombardment than the conventional stainless steel collector, is adopted. Meanwhile, water-cooling technology is applied to expedite heat dissipation of the collector. Second, since our investigations demonstrate that an anodic mechanism, not the conventional cathodic mechanism, is the main cause for RF breakdown of electrodynamic structures under strong guiding magnetic field, the titanium material is also used to manufacture the electrodynamic structures of the RBWO in order to increase its power capacity. The advantage of the titanium RBWO is verified in experiments. The application of these techniques, as well as some important surface treatment techniques such as polishing, ultrasonic washing, and vacuum baking, leads to the stable repetitive operation of the RBWO with 3-GW output power and 25-ns microwave duration under a repetition rate of 50 Hz. The successive operation time of the device is up to 20 s. [ABSTRACT FROM AUTHOR]

Conventional AlexNet has the problems of slow training speed, single characteristic scale and low recognition accuracy. To solve these problems, a convolutional neural network identification model based on Inception module and dilated convolution is proposed in this study. The inception module combined with dilated convolution, could extract disease characteristics at different scales and increase the receptive field. By setting different parameters, six improved models were obtained. They were trained to identify 26 diseases of 14 different crops; then the authors selected optimal recognition model. On this basis, the segmented dataset and the grey‐scaled dataset were trained as comparative experiments to explore the influence of background and colour features on the recognition results. After only two training epochs, the improved optimal model could achieve an accuracy of over 95%. Moreover, the final average identification accuracy reached 99.37%. Contrast experiments indicate that colour and background features may influence the recognition effect. The improved model can extract disease information from different scales in the feature map to identify diverse diseases of different crops. The proposed model has faster training speed and higher recognition accuracy than the traditional model, and thus it can provide a reference for crop disease identification in actual production. [ABSTRACT FROM AUTHOR]

Background and Objective: Both periodontal disease and inflammatory bowel disease (IBD), are chronic inflammatory conditions, which are mediated by a complex interplay among a dysbiotic microbiota, dysregulated host immune-inflammatory responses, and lifestyle factors. Despite substantial differences in physical and chemical environments, rather strong correlations have been detected between microbial compositions of the oral cavity and stool. In this study, we tested the hypothesis that oral health conditions are affected by the presence of IBD. Materials and Methods: We analyzed the data from 73,621 women who were enrolled in the Women's Health Initiative observational cohort study and completed a follow-up questionnaire that surveyed oral health status specifically at year 5. Among these, 880 reported IBD at the baseline, including 47% who were symptomatic cases and 27% who were on immunosuppressive treatment. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association of IBD and medication status for self-reported oral health outcomes, using logistic regression models, adjusted for selected covariates. Results: IBD was not associated with periodontal disease history itself in a multivariable model; however, poorer self-rated oral health was modestly associated with the presence of IBD (OR = 1.15, 95% CI: 1.01–1.30). Likewise, more frequent eating limitations due to teeth were associated with the presence of IBD history (OR = 1.22, 95% CI: 1.07–1.39). When IBD cases were limited to those who were symptomatic, the associations with these two self-rated oral health outcomes were more pronounced with ORs of 1.28 (95% CI: 1.07–1.54) and 1.36 (95% CI: 1.07–1.54), respectively. Immunosuppressive treatment had little effect on these risk estimates. Conclusions: Among this nation-wide cohort of women 50–79 years of age, history of IBD was associated with poorer perceived oral health status. [ABSTRACT FROM AUTHOR]

A new 3 D polyoxometalate, H7K3[Na2Cu3(H2O)(B-α-SbW9O33)2]·8H2O (1), has been hydrothermally made and characterized by IR spectroscopy, thermogravimetric analyses, powder X-ray diffraction and single crystal X-ray diffraction analysis. 1 crystallizes in the tetragonal system, space group P-421m, with a = 16.7532(7) Å, b = 16.7532(7) Å, c = 13.8335(11) Å and Z = 2. Structure analysis reveals that the polyanion in 1 consists of two B-α-SbW9O33 ({SbW9}) units sandwiched by a U-shaped {Na2Cu3} cluster made by two Na+ and three Cu2+ ions. The most prominent structural feature of 1 is that the [Na2Cu3(H2O)(B-α-SbW9O33)2]10– ({Na2Cu3(SbW9)2}) units are connected to construct a 2 D network through Cu–O = W bridges. To the best of our knowledge, 1 represents the first sample with an unclosed central belt between two {SbW9} fragments. Furthermore, neighboring 2 D networks connect by K+ cations to form a 3 D framework. The semiconductor behavior, electrochemical properties and photocatalytic activities have been investigated, showing excellent photocatalytic and electrocatalytic activities for the photodegradation of MB/RhB and bromate reduction. [ABSTRACT FROM AUTHOR]

The breakdown problem in the relativistic backward wave oscillator (RBWO) limits the microwave pulse energy and should be solved. The slow wave structure (SWS) is the most key component of the RBWO. The breakdown of SWS may be triggered by field-induced electron emission and electron bombardment on the wall. This paper demonstrates that the space charge field of the relativistic electron beam (REB) can enhance the electric field forbidding field-induced electron emission and decrease the electric field igniting the RF breakdown, and therefore, the RF breakdown can be significantly suppressed. However, the enhanced electric field will enlarge the radial displacements of electrons, especially the high-energy electrons. When the RBWO operates with a low guiding magnetic field or a long-pulse REB, this situation will worsen and some electrons may possess large enough radial displacements and bombard on the SWS surface with the help of radial oscillation of REB and radial expansion of cathode plasmas. This may aggravate the breakdown of SWS. [ABSTRACT FROM AUTHOR]

The high-temperature gas-cooled reactor pebble-bed module (HTR-PM) nuclear power plant consists of two nuclear steam supply system modules, each of which drives the steam turbine by the superheated steam flow and is fed by the heated-up water flow. The shared steam/water system induces mutual effects on normal operation conditions and transients of the nuclear power plant, which is worthy of safety concerns and intensive study. In this paper, a coupling code package was developed with the TINTE and vPower codes to understand how the HTR-PM operated. The TINTE code was used to analyze the reactor core and primary circuit, while the vPower code simulated the steam/water flow in the conventional island. Two TINTE models were built and coupled to one vPower model through the data exchange in the steam generator models. Using this code package, two typical transients were simulated by decreasing the primary flow rate or introducing the negative reactivity of one module. Important parameters, including the reactor power, the fuel temperature, and the reactor inlet and outlet helium temperatures of two modules, had been studied. The calculation results preliminarily proved that this code package can be further used to evaluate working performance of the HTR-PM. [ABSTRACT FROM AUTHOR]

Nonnegative sparsity-constrained optimization problem arises in many fields, such as the linear compressing sensing problem and the regularized logistic regression cost function. In this paper, we introduce a new stepsize rule and establish a gradient projection algorithm. We also obtain some convergence results under milder conditions. [ABSTRACT FROM AUTHOR]

To compare the clinical outcome between bilateral percutaneous endoscopic debridement and lavage (PEDL) and unilateral PEDL treatment for lumbar spine tuberculosis (LST). A total of 40 patients with LST who underwent either bilateral PEDL (group A) or unilateral PEDL (group B) were reviewed. Perioperative parameters were assessed by operative time, intraoperative fluoroscopy times, and days of postoperative continuous irrigation and vacuum drainage. Clinical outcomes were evaluated in the Oswestry Disability Index (ODI), visual analog scale (VAS), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). All patients were followed-up for at least 18 months after treatment. The average operative time and intraoperative fluoroscopy time were increased in group A compared with those in group B. There was no statistical significance between the 2 groups in postoperative continuous irrigation and vacuum drainage days. The ESR and CRP curves in the 2 groups showed a similar trend during 18-month follow-up. The VAS and ODI in the 2 groups significantly decreased 6 and 18 months postsurgery. There was no significant difference in the incidence of complication between the 2 groups. Two procedures yielded comparable and satisfactory results. Unilateral PEDL showed shorter operative time and decreased intraoperative fluoroscopy times compared with bilateral PEDL. We suggest the use of unilateral PEDL rather than bilateral PEDL in the treatment of LST. [ABSTRACT FROM AUTHOR]

In order to identify saccharin jujube more quickly and effectively, this article used hyperspectral imaging technology to explore a new detection method. About 240 winter jujubes under four gradients of saccharin stress were prepared, and the original spectra of them were collected. First, a hybrid method was used to preprocess original spectra, which improved the signal‐to‐noise ratio of spectra. Then, three feature extraction methods were adopted to extract feature wavelengths from the spectra after pretreatment, respectively. Subsequently, support vector machines (SVM) was employed to form the classification models based on feature spectra and raw spectra. Because the random parameters (C, g) of SVM affected the ability of model, three intelligent algorithms were used to tune the parameters of SVM, respectively. Finally, the classification accuracy of the final model (VISSA‐GWO‐SVM) reached best result with accuracy of 91.67%. Therefore, hyperspectral imaging technology combined with VISSA‐GWO‐SVM model is a feasible method to identify saccharin jujube. Practical applications: Traditional methods for identification of saccharin jujube mainly depended on the experience of consumers and destructive and time‐consuming testing. In order to overcome the shortcomings of traditional detection methods, hyperspectral imaging technology was used to identify saccharin jujube. Then, the optimal model (VISSA‐GWO‐SVM) was established in this paper, and the recognition accuracy reached a best value. Thus, hyperspectral imaging technology combined with the VISSA‐GWO‐SVM model could be a rapid, precise, and nondestructive method for food safety and market supervision departments to ensure food safety. [ABSTRACT FROM AUTHOR]

We prove some differentiable sphere theorems and topological sphere theorems for Lagrangian submanifolds in Kähler manifold and Legendrian submanifolds in Sasaki space form. [ABSTRACT FROM AUTHOR]

A new telluroborate Rb3BaTeB7O15, with a new type of fundamental building block, namely [B7O16] units, has been synthesized by the high-temperature flux method, and it crystallizes in the monoclinic space group P21/n (no. 11) with a three dimensional network. To the best of our knowledge, Rb3BaTeB7O15 is the first telluroborate that is constructed only by using [TeO3] polyhedra. Meanwhile, the stereochemical activity of the [TeO3] polyhedra was demonstrated by employing theoretical calculations. The UV-vis-NIR diffuse reflectance spectrum, thermal gravimetric results, differential scanning calorimetry curves and infrared spectrum of Rb3BaTeB7O15 were characterized and analyzed. In addition, the electronic structures and birefringence were discussed by using the first-principles calculations. [ABSTRACT FROM AUTHOR]

Background: Protein-ligand docking has emerged as a particularly important tool in drug design and development, and flexible ligand docking is a widely used method for docking simulations. Many docking software packages can simulate flexible ligand docking, and among them, Autodock is widely used. Focusing on the search algorithm used in Autodock, many new optimization approaches have been proposed over the last few decades. However, despite the large number of alternatives, we are still lacking a search method with high robustness and high performance. Results: In this paper, in conjunction with the popular Autodock software, a novel hybrid version of the random drift particle swarm optimization (RDPSO) algorithm, called diversity-guided Lamarckian RDPSO (DGLRDPSO), is proposed to further enhance the performance and robustness of flexible ligand docking. In this algorithm, a novel two-phase diversity control (2PDC) strategy and an efficient local search strategy are used to improve the search ability and robustness of the RDPSO algorithm. By using the PDBbind coreset v.2016 and 24 complexes with apo-structures, the DGLRDPSO algorithm is compared with the Lamarckian genetic algorithm (LGA), Lamarckian particle swarm optimization (LPSO) and Lamarckian random drift particle swarm optimization (LRDPSO). The experimental results show that the 2PDC strategy is able to enhance the robustness and search performance of the proposed algorithm; for test cases with different numbers of torsions, the DGLRDPSO outperforms the LGA and LPSO in finding both low-energy and small-RMSD docking conformations with high robustness in most cases. Conclusion: The DGLRDPSO algorithm has good search performance and a high possibility of finding a conformation with both a low binding free energy and a small RMSD. Among all the tested algorithms, DGLRDPSO has the best robustness in solving both holo- and apo-structure docking problems with different numbers of torsions, which indicates that the proposed algorithm is a reliable choice for the flexible ligand docking in Autodock software. [ABSTRACT FROM AUTHOR]

Traditional detection methods are not sensitive to small-sized tomato organs (flowers and fruits), because the immature green tomatoes are highly similar to the background color. The overlap among fruits and the occlusion of stems and leaves on tomato organs can lead to false and missing detection, which decreases the accuracy and generalization ability of the model. Therefore, a tomato organ recognition method based on improved Feature Pyramid Network was proposed in this paper. To begin with, multi-scale feature fusion was used to fuse the detailed bottom features and high-level semantic features to detect small-sized tomato organs to improve recognition rate. And then repulsion loss was used to take place of the original smooth L1 loss function. Besides, Soft-NMS (Soft non-maximum suppression) was adopted to replace non-maximum suppression to screen the bounding boxes of tomato organs to construct a recognition model of tomato key organ. Finally, the network was trained and verified on the collected image data set. The results showed that compared with the traditional Faster R-CNN model, the performance was greatly improved (mean average precision was improved from 90.7 to 99.5%). Subsequently, the training model can be compressed so that it can be embedded into the microcontroller to develop further precise pesticide targeting application system of tomato organs and the automatic picking device. [ABSTRACT FROM AUTHOR]

Background and Objective: Both periodontal disease and inflammatory bowel disease (IBD), are chronic inflammatory conditions, which are mediated by a complex interplay among a dysbiotic microbiota, dysregulated host immune-inflammatory responses, and lifestyle factors. Despite substantial differences in physical and chemical environments, rather strong correlations have been detected between microbial compositions of the oral cavity and stool. In this study, we tested the hypothesis that oral health conditions are affected by the presence of IBD. Materials and Methods: We analyzed the data from 73,621 women who were enrolled in the Women's Health Initiative observational cohort study and completed a follow-up questionnaire that surveyed oral health status specifically at year 5. Among these, 880 reported IBD at the baseline, including 47% who were symptomatic cases and 27% who were on immunosuppressive treatment. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association of IBD and medication status for self-reported oral health outcomes, using logistic regression models, adjusted for selected covariates. Results: IBD was not associated with periodontal disease history itself in a multivariable model; however, poorer self-rated oral health was modestly associated with the presence of IBD (OR = 1.15, 95% CI: 1.01–1.30). Likewise, more frequent eating limitations due to teeth were associated with the presence of IBD history (OR = 1.22, 95% CI: 1.07–1.39). When IBD cases were limited to those who were symptomatic, the associations with these two self-rated oral health outcomes were more pronounced with ORs of 1.28 (95% CI: 1.07–1.54) and 1.36 (95% CI: 1.07–1.54), respectively. Immunosuppressive treatment had little effect on these risk estimates. Conclusions: Among this nation-wide cohort of women 50–79 years of age, history of IBD was associated with poorer perceived oral health status. [ABSTRACT FROM AUTHOR]

Moisture content was an important indicator to measure quality of green tea. In order to detect moisture content in green tea effectively and accurately, nondestructive detection for moisture content in green tea based on dielectric technology was proposed in this paper. Inductance‐capacitance‐resistance (LCR) measuring instrument and coaxial‐line cylinder capacitor were used to collect dielectric data. The characteristic frequency points were extracted by successive projection algorithm (SPA) and variable iterative space shrinkage approach (VISSA). Support vector regression (SVR) was used to establish prediction models based on full frequency points and characteristic frequency points. The model results demonstrated that VISSA‐SVR model based on dielectric loss factor ε″ performed best among all the prediction models, but the prediction accuracy was not enough, so the gray wolf optimization (GWO) algorithm was introduced to optimize the parameters (c and g) in SVR model. Furthermore, the best prediction performances for detecting moisture content in green tea was obtained, with the determination coefficient and root mean square errors (RMSEs) for prediction were 0.9695 and 0.0602, respectively. Therefore, dielectric technology combined with VISSA‐GWO‐SVR model is feasible for nondestructive determination of the moisture content in tea, which will provide a promising tool for the moisture content detection of other agricultural products. Practical applications: Well understanding moisture content in tea is great importance. The practical application of this paper is to develop a novel method for moisture content detection in tea using dielectric technology. Compared with traditional methods, dielectric technology can be used to detect moisture content in tea nondestructively and accurately. Characteristic frequency selection algorithms are used to remove the redundant information in the data, and optimization algorithm is used to improve the performance of the model. Thus, dielectric technology combined with the optimal model is considered the most promising method for detecting the moisture content in green tea. [ABSTRACT FROM AUTHOR]

It is shown that graphitic shells encapsulating metal nanoparticles facilitate the amorphization of metals and stabilize the amorphous phase against recrystallization. In an in-situ electron microscopy experiment, where the objects are exposed to laser pulses during their observation, the amorphization of iron and cobalt nanocrystals in graphitic shells is demonstrated. The infrared nanosecond pulses lead to fast melting of the metal which then dissolves carbon atoms from the shell. Fast cooling of the liquid solution after the pulse results in the solidification of an amorphous metal-carbon phase. The amorphous phase is metastable and can be recrystallized by repeated laser pulses or slow thermal annealing. The recrystallization needs heterogeneous nucleation but is unfavorable at the metal-graphite interface and so stabilizes the amorphous phase against recrystallization. The analysis of the experiments explains the formation mechanisms of an amorphous metal-carbon phase as a metastable solution of carbon in a transition metal and shows how that the encapsulation by a graphitic shell can be a route towards the stabilization of otherwise unfavorable amorphous metal or metal-carbon phases. Image 1 [ABSTRACT FROM AUTHOR]

The validity and reliability of visible–near infrared (Vis–NIR) hyperspectral imaging were investigated for the determination of lead concentration in lettuce leaves. Besides, a method involving wavelet transform and stacked auto-encoders (WT-SAE) is proposed to decompose the spectral data in the multi-scale transform and obtain the deep spectral features. The Vis–NIR hyperspectral images of 1120 lettuce leaf samples were obtained and the whole region of lettuce leaf sample spectral data was collected and preprocessed. In addition, WT-SAE the deep spectral features using db5 as wavelet basis function, and support vector machine regression (SVR) was used for regression modelling. Furthermore, the best prediction performances for detecting lead (Pb) concentration in lettuce leaves was obtained from raw data set, with coefficient of determination for calibration (Rc2) of 0.9911, root mean square error for calibration (RMSEC) of 0.05187 m g k g − 1 , coefficient of determination for prediction (Rp2) of 0.9590, root mean square error for prediction (RMSEP) of 0.05587 m g k g − 1 and residual predictive deviation (RPD) of 3.251 using db5 as wavelet basis function with wavelet fifth layer decomposition. The results of this study indicated that WT-SAE can effectively select the optimal deep spectral features and Vis–NIR hyperspectral imaging has great potential for detecting lead content in lettuce leaves. [ABSTRACT FROM AUTHOR]

Through a study of the publication data about translations in the field of geography in China from 1900 to 2017, this paper discusses translation as an inherent factor implying foreign geography's impact on modernising and promoting geography in China. The progress of geographical translation in China has been circuitous and arduous, and can be classified into four distinct yet interconnected phases according to the four‐fold aspects of growth, dominant origin, main field of the translations, and proportion of translations among the selected published works. Although translation has been so ubiquitous in Chinese geography that it seems the impact of foreign geography is inescapable, "impact" cannot be equal to translation. With that in mind, indicators including the number and proportion of translations, the import and absorption of translations, the intertwined variation of translations from various countries in different fields and phases, and the social and political contexts in China are considered. The discussion demonstrates that the role of translation in the growth of geography in China changed situationally, and translation implied not only a "foreign impact" but also a "domestic remodelling" of the discipline. Although the status of geography in China is very different from what it used to be, this conclusion suggests that "importing" quality work is necessary for the further promotion of Chinese geography. [ABSTRACT FROM AUTHOR]

High temperatures and low oxygen in aquatic environments, such as intensive aquaculture or in natural watersheds, inevitably cause stress in fish. Fish are exposed to high temperatures during the summer, which exacerbates hypoxia. Hypoxia (1.2 ± 0.2 mg/L) under 20 °C (20 HG) and 26 °C (26 HG) was simulated to induce stress in largemouth bass (Micropterus salmoides). Related enzymes and genes involved in antioxidant, immune, and apoptotic responses were selected to explore the interactive effects of temperature and hypoxia on largemouth bass. The results showed that malondialdehyde (MDA) levels in plasma, gill, and liver increased in the 26 HG (p < 0.05). Liver superoxide dismutase (SOD) activity increased in the 26 HG. Peak SOD (SOD1, SOD2, SOD3a, and SOD3b), CAT , and GSH-Px mRNA levels in the gill and liver were observed at 12–24 h of stress. The levels of gill and liver total antioxidant capacity, catalase (CAT), glutathione peroxidase (GSH-Px) activities and other enzyme activities and genes in the 26 HG were higher than those in the 20 HG (p < 0.05). The gill and liver acid phosphatase and alkaline phosphatase activities increased with time in the 26 HG (p < 0.05), while gill and liver lysozyme activities in the 26 HG were lower than those in the 20 HG (p < 0.05). Tumor necrosis factor-α mRNA level was upregulated in the gill and downregulated in the liver at 24 h in the 26 HG. Interleukin (IL)-1β and IL- 8 mRNA levels were upregulated in the gill and liver in the 26 HG at 24 h, whereas IL- 15 mRNA level was downregulated in the 26 HG at 12 h. Transforming growth factor-β1 mRNA level was upregulated in the gill in the 20 HG at 24 h, but downregulated in gill and liver in the 26 HG at 24 h. Similarly, IL-10 , Hepcidin-1 , and Hepcidin-2 showed lower expression levels in the 26 HG. Gill and liver caspase-3 activities were higher in the 26 HG (p < 0.05), and gill caspase-3 activity was higher than that in the liver. The mRNA levels of proapoptotic genes (caspase-3 , caspase-8 , and caspase-9) were higher in the 26 HG. The present study demonstrates the interactive effects of temperature and hypoxia on stress in largemouth bass gill and liver. These results will be helpful to understand the mechanisms of stress induced by temperature and hypoxia in fish and provide a theoretical basis for aquaculture management. • High temperature aggravates oxidative stress in gill and liver under acute hypoxia. • Immune response in gill and liver is inhibited under high temperature and hypoxia. • Combined effect of heat and hypoxia promotes gill and liver cell apoptosis. [ABSTRACT FROM AUTHOR]

Open-phase fault is a common failure in permanent magnet synchronous motor (PMSM), which would degrade motor performance and increase its loss due to the unbalanced phase currents. However, conventional fault-tolerant strategies suffer from the tracking problem of sinusoidal current references. In this paper, different from previous fault-tolerant strategies, a new fault-tolerant method for open-phase PMSM is proposed by designing a novel transformation matrix for current/voltage references. With the new transformation matrix, the voltage/current references in the d–q frame can be transformed to the phase voltage/current references of the two remaining phases. With the proposed method, open-phase fault-tolerant implementation can be much easier (proportional-integral controller is enough) and its performance can be much higher. Besides, as the tolerant method is designed based on the four-leg inverter, stronger fault-tolerance capability can be obtained compared with the three-phase inverter-based method. Finally, the experimental results confirm the validity of the proposed fault-tolerant method. [ABSTRACT FROM AUTHOR]

A new hexa‐TiIV‐substituted sandwich‐type silicotungstate, Na2(H2enMe)4[Ti6(µ‐O)9(A‐α‐SiW9O34H2)2]·16H2O (1, enMe = 1,2‐diaminopropane) has been synthesized under mild hydrothermal conditions and characterized by FT‐IR spectroscopy, elemental analysis, thermogravimetric analysis, single‐crystal and powder X‐ray diffraction. Compound 1 contains a dimeric polyoxoanion with two [A‐α‐SiW9O34]10– Keggin moieties sandwiching a trigonal‐prismatic [Ti6(µ‐O9)]6+ cluster. The catalytic performance of 1 was evaluated for the oxidative decontamination of chemical warfare agent, i.e. sulfur mustard simulant, 2‐chloroethyl ethyl sulfide (CEES), using H2O2 under ambient conditions, showing that 1 is an excellent catalyst for the rapid and complete transformation from CEES to nontoxic 2‐chloroethyl ethyl sulfoxide (CEESO) with 100 % selectivity. In addition, 1 exhibits good stability and recyclability. [ABSTRACT FROM AUTHOR]

Dysregulation of microRNAs (miRNAs) is involved in the pathogenesis of esophageal cancer. miRNA (miR)-542-3p is a tumor suppressor in multiple types of cancer. However, whether and how miR-542-3p contributes to the progression of esophageal cancer remains unknown, and this is the aim of the present study. In the current study, decreased expression of miR-542-3p was detected in tumor tissues compared with normal tissues from patients with esophageal cancer, and miR-542-3p expression was negatively correlated with mRNA expression levels of ovarian tumor domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1) in tumor tissues from patients with esophageal cancer. In KYSE150 human esophageal squamous cell carcinoma cells, overexpression of miR-542-3p significantly decreased OTUB1 at mRNA and protein levels, whereas downregulation of miR-542-3p significantly increased OTUB1 expression. Using a dual-luciferase assay, OTUB1 was validated to be a target gene of miR-542-3p in KYSE150 cells. Functionally, miR-542-3p significantly inhibited the migration and invasion of KYSE150 cells by repression of OTUB1 expression. These results demonstrated that miR-542-3p may promote the metastasis of esophageal cancer cells, and indicated that miR-542-3p may be a treatment target for esophageal cancer. [ABSTRACT FROM AUTHOR]

Purpose: Currently, lubrication analysis of piston ring is generally done under engine rated operating condition. However, the engine (such as the vehicle engine) does not always operate in rated operating condition, and its operating condition changes frequently in actual use. In addition, the lubrication status of piston ring is generally assumed as the flooded lubrication or a certain form of poor lubrication in most of the lubrication analysis. Design/methodology/approach: In this paper, based on the equations about the flow rate of lubricating oil and the variation of control volume, the flow model of lubricating oil in the piston ring-cylinder liner conjunction is established. The lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done, in which the lubricating oil at the inlet of piston ring is considered as the lubricating oil attached on the relevant location of cylinder wall after the piston ring moves over at the previous stroke. Findings: There is remarkable difference for the lubrication characteristics of the piston ring under different engine operating conditions. The worst lubrication status of piston ring may not take place under engine rated operating condition. Originality/value: In this paper, based on the measured engine cylinder pressure, the lubrication analysis of piston ring for a four-stroke engine under different engine operating conditions is done in which the lubricating oil supply condition at the inlet of piston ring is considered. The results of this paper are helpful for the design and research of engine piston ring-cylinder liner conjunction. [ABSTRACT FROM AUTHOR]

In this note, we prove that for a 3-dimensional submanifold in an η -Einstein 5-Sasaki manifold with Einstein constant a ≥ 4 , if the Reeb vector field is tangent to the submanifold and it has parallel mean curvature form, then it is a slant submanifold. Furthermore, if a > 4 , then it is either an invariant submanifold or an anti-invariant submanifold. [ABSTRACT FROM AUTHOR]

The paper presents a novel variable structure control with finite time sliding sector for spacecraft atmospheric entry guidance. The finite time convergence of tracking error in the presence of system uncertainty can be guaranteed. In contrast with the normally used notion of asymptotic stability in conventional sliding sector, a finite time sliding sector for the entry guidance is designed as a subset of state space in which the Lyapunov function candidate satisfies the finite time stability condition. Then, the finite time sliding sector controller is designed to guarantee the tracking error to converge to a small region of zero. The chattering existing on the boundary of the sliding sector is further reduced by introducing inner sector and outer sector which are the subsets of the proposed sector. Finally, numerical simulation results are given to demonstrate the effectiveness of the proposed method. • Finite time stability is guaranteed inside the proposed sector. • The proposed method can deal with unmatched parameter uncertainties. • Chattering can be further reduced by introducing inner sector and outer sector. [ABSTRACT FROM AUTHOR]

The present study focused on exploring the inhibitory mechanism of microRNA (miR)-23a in endometrial cancer. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to investigate miR-23a expression in endometrial tissues and endometrial cancer cells. A colony formation assay using crystal violet staining was performed to compare cell proliferation, while wound-healing and Transwell assays were performed to compare cell migration and invasion. Subsequently, bioinformatics and a luciferase reporter gene assay were used to investigate the effect of miR-23a on sine oculis homeobox homolog 1 (SIX1) expression, and the biological function of SIX1 was analyzed. Additionally, a nude mouse tumorigenicity assay was performed to test the inhibitory effect of miR-23a and Taxol® therapy in endometrial cancer. Finally, immunohistochemistry and RT-qPCR were used to explore the association between miR-23a and SIX1 expression in endometrial cancer tissues. miR-23a was underexpressed in endometrial cancer tissues compared with in para-carcinoma tissues, and the overexpression of miR-23a inhibited proliferation and invasion of endometrial cancer cells. Furthermore, SIX1 was demonstrated to be a downstream target of miR-23a, and miR-23a reduced SIX1 expression. Additionally, SIX1 inversely promoted cell proliferation, migration and invasion. In addition, the effects of reduced cell proliferation and increased cell invasion following miR-23a overexpression could be reversed by adding SIX1 to in vitro culture. Furthermore, the inhibitory effect of miR-23a and Taxol therapy, which reduced SIX1 expression in endometrial cancer, was demonstrated in vivo. Finally, a negative association between miR-23a and SIX1 expression was demonstrated in endometrial cancer tissues. The results of the present study revealed that miR-23a may inhibit endometrial cancer development by targeting SIX1. [ABSTRACT FROM AUTHOR]

Since the first case of the hemolytic disease of the fetus and newborn (HDFN) caused by anti-K was reported in 1946, the fetal diagnosis of K-HDFN has made rapid progress from invasive immunological and biochemical tests to noninvasive Doppler ultrasound and molecular biology techniques. However, its treatment, especially prenatal intervention, has developed slowly compared with RhD-HDFN. This review attempts to clarify the current key points and explore the direction of the next phase by systematically reviewing the development of diagnosis and treatment of this disease, which involving multidisciplinary participation. [ABSTRACT FROM AUTHOR]

Three mixed-metal phosphates, namely, centrosymmetric LiSrP3O9 and LiCsP2O6 as well as noncentrosymmetric K2SrP4O12 have been synthesized by the high temperature solution method. These structures were characterized by single-crystal X-ray diffraction and their P–O units are shown to feature distinct polyanionic configurations from [PO3]∞ chains in LiSrP3O9 to [P4O12]4− rings in LiCsP2O6 and K2SrP4O12. Besides, K2SrP4O12 shows a moderate second harmonic generation response about 0.6 times that of KH2PO4 and can be applied as a potential nonlinear optical material for the ultraviolet spectral region. Thermal behaviour analyses indicate that the compounds LiSrP3O9 and K2SrP4O12 remain stable up to 659 and 698 °C, respectively. In addition, the crystal structures, thermal stabilities and infrared spectra of the title compounds have been examined. [ABSTRACT FROM AUTHOR]

Sparse representation-based classification (SRC) and collaborative representation-based classification (CRC) have garnered significant attention recently. In CRC, it is argued that it is the collaborative representation mechanism but not the ℓ[sub 1]-norm sparsity that makes SRC successful for classification tasks. However, recent studies reveal that sparsity does play a critical role in accurate classification, thus it should not be totally overlooked due to relatively high computational cost. Inspired by these findings, we propose a method called sparsity augmented weighted collaborative representation-based classification (SA-WCRC) for image classification. First, the representation coefficients of the test sample are obtained via weighted collaborative representation and sparse representation, respectively. Second, we augment the coefficient obtained by weighted collaborative representation with the sparse representation. Finally, the test sample is classified based on the augmented coefficient and the label matrix of the training samples. Both the augmented coefficient and classification scheme make SA-WCRC efficient for classification. Experiments on three face databases and one scene dataset demonstrate the superiority of SA-WCRC over its counterparts. [ABSTRACT FROM AUTHOR]

Asymmetric modes competition in Cerenkov devices were studied with a view to developing a novel method to suppress modes competition, based on loading of the slow-wave structure (SWS) with an anisotropic medium. Due to differences in the field distribution between the asymmetric and symmetric modes, the asymmetric modes are susceptible to significant attenuation in anisotropic media with an appropriate imaginary part for the azimuthal permittivity. In contrast, the symmetric modes, such as the TM01 mode, incur no such losses. Using the EH11 mode as an example, the quality factor obtained from experiments involving the SWS loaded with an anisotropic medium was reduced by approximately 90% compared with that for a copper SWS. The attenuation was sufficiently high that the electromagnetic fields for the asymmetric modes were barely established, indicating that the suppression technique was highly effective. The approach provides a feasible way to eliminate asymmetric modes in high-power microwave (HPM) sources and may lead to a range of new applications in HPM systems. [ABSTRACT FROM AUTHOR]

Currently used turbulent lubrication model that considers the effects of surface roughness can only handle the isotropic rough surfaces and cannot handle the rough surfaces with directional properties. In this paper, based on the stochastic method and the Ng-Pan turbulent model, the stochastic turbulent lubrication models of one-dimensional longitudinal rough surface, one-dimensional transverse rough surface and isotropic rough surface are derived. The turbulent lubrication performance of a journal bearing with isotropic rough surface is calculated by the stochastic turbulent lubrication model. The results are in good agreement with the corresponding experimental data. Moreover, the proposed stochastic turbulent lubrication models are also suitable for parts of friction pairs such as journal bearing and thrust bearing. • Stochastic method is used to study bearing with rough surfaces. • Turbulent models of longitudinal, transverse and isotropic rough surface are derived. • The derived stochastic turbulence model is suitable for any type of bearing. [ABSTRACT FROM AUTHOR]

We theoretically study mode selection characteristics in a left-handed metamaterial (LHM) loaded into a circular waveguide. The existent modes in the circular waveguide are closely related to the radius of the coaxially loaded LHM, and a general rule that determines whether one mode can exist in the structure is given in this paper. Therefore, the modes in the circular waveguide can be controlled by adjusting the radius of the loaded LHM. For a specific, normalized boundary radius, only one mode is capable of existing in the structure. Moreover, we discuss the variation in the cutoff frequency for different modes as a function of the LHM radius. We find that the eigenfrequencies of almost all waveguide modes increase sharply when the LHM radius approaches half the waveguide radius. These properties may lead to a wide range of applications such as controllable mode microwave generators and perfect waveguide reflectors. [ABSTRACT FROM AUTHOR]

In order to rapidly and nondestructively identify tea grades, fluorescence hyperspectral imaging (FHSI) technology was proposed in this paper. A total of 309 Tieguanyin tea samples with three different grades were collected and the fluorescence hyperspectral data was acquired by hyperspectrometer (400 to 1000 nm). The characteristic wavelengths were respectively selected by Bootstrapping Soft Shrinkage (BOSS), Variable Iterative Space Shrinkage Approach (VISSA) and Model Adaptive Space Shrinkage (MASS) algorithms. Then, Support Vector Machine (SVM) was applied to establishing the relationship between the characteristic peaks, the full spectra, three characteristic spectra and the labels of tea grades. The results showed that VISSA‐SVM model had the best classification performance, but the model precision can still be improved. Thus, Artificial Bee Colony (ABC) algorithm was introduced to optimize the parameters of SVM model. The accuracy and Kappa coefficient of test set of VISSA‐ABC‐SVM model were improved to 97.436% and 0.962, respectively. Therefore, the combination of fluorescence hyperspectra with VISSA‐ABC‐SVM model can accurately identify the grade of Tieguanyin tea. Practical Application: The rapid and accurate nondestructive tea grade identification method contributes to the construction of the tea online grade detection system. FHSI technology can solve the shortcomings of the reported methods and improved the identification accuracy of tea grades. It can be applied to the rapid detection of tea quality by tea companies, tea market, tea farmers and other demanders. [ABSTRACT FROM AUTHOR]

The Chinese High Temperature Reactor Pebble-bed Module (HTR-PM) is the world first commercial nuclear power plant (NPP) with the characteristics of fourth generation. Accident diagnosis tasks for HTR-PM are directly associated with safe and efficient operation. Although different kinds of accident diagnosis methods have been studies on conventional NPPs, the research of accident diagnosis of HTR-PM is relatively lacking according to the different characteristics and new applications of HTR-PM. In this article, a new algorithm for HTR-PM accident diagnosis based on deep learning methods is proposed. By using the preprocessing, classification network and postprocessing techniques, the proposed algorithm could avoid over-reliance on the previous experiences and make fully use of the signals, also it can use only few number of training signal sequences to get high accuracy results, which is a significant advantage compared with traditional algorithms using deep learning methods. This algorithm is tested using the signals produced by the engineering simulator of HTR-PM for normal state and several accidents, including loss of feed water, large break depressurized loss of forced cooling, small break depressurized loss of forced cooling and inadvertent withdrawal of a single control rod. The results show the feasibility and effectiveness of the algorithm for HTR-PM accident diagnosis, and also the potentiality to use in other NPPs accident diagnosis tasks. [ABSTRACT FROM AUTHOR]

By extracting information from various original materials and using geography departments, curricula, and faculty as indicators, this paper contributes to the discussion of the development of geography in higher education in China from 1904 to 1949. Four mutual connections are outlined. First, the development of geography in higher education is inextricably linked to social and political changes. Second, geography in higher education during the period concerned progressed in fits and starts, which affected its distribution. Third, geography departments were split into two categories according to the type of higher educational institution, which created differences in the tasks, curricula, and faculty of these departments. Fourth, faculty were trained in both domestic and foreign universities, and Western universities made an obvious contribution to the growth of qualified academic faculty. Simultaneously, universities where qualified academic faculty were trained were centralized both in domestic and foreign aspects. The special role of geographers returning from overseas study, the particularity of geography in higher education in China, and the connection between Chinese and foreign geography are also discussed in terms of geography departments, curricula, and faculty. [ABSTRACT FROM AUTHOR]

To achieve phase locking of high power microwave oscillators on a relatively weak coupling strength, an inducing phase locking method is investigated. With an external signal injected from the end of relativistic backward wave oscillator, the frequency and phase of the output microwave is pulling in the starting oscillation process and remaining stable in the later stationary oscillation process. The simulation results indicate that injecting of inducing signal prior to the onset of natural oscillations is necessary, while the duration of injection, power of injection and locking bandwidth are not limited by classic Adler's law. [ABSTRACT FROM AUTHOR]

To increase the efficiency of the magnetically insulated line oscillator (MILO) and expand its frequency band, a coaxial transit time oscillator (TTO) is introduced to use the load currents of an annular MILO, called the annular MILO-TTO, which comprises an inward-emitting MILO, an outward-emitting MILO, and a coaxial TTO. In simulation, when the input power is 78 GW and the diode voltage is 520 kV, three microwaves with powers of 3.2, 9.6, and 7.0 GW are generated, with a total efficiency of 25.4%, in the inward-emitting MILO, the outward-emitting MILO, and the coaxial TTO, and the frequencies are 1.7, 3.3, and 4.2 GHz, corresponding to L, S, and C bands, respectively. [ABSTRACT FROM AUTHOR]