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The rotor system is the core equipment of industrial rotating machinery, and ensuring its safety is an essential basis for improving the productivity of the equipment. As a critical monitoring quantity reflecting the operating status of the rotor system, identification models based on axis orbits are effective means for detecting equipment faults. However, most of the existing axis orbit identification models belong to the category of image recognition, and these methods have defects such as unclear physical meaning of features and weak generalization performance. Therefore, the paper returns to the essence of axis orbits and proposes a rotor axis orbit recognition method based on multivariate swing signals, feature extraction and pattern recognition. Firstly, the mutually perpendicular swing signals of the rotor are obtained based on eddy current sensors. Secondly, we propose a feature extraction tool for extracting the multivariate signals named enhanced hierarchical multivariate fuzzy entropy (EHMvFE), a nonlinear dynamics metric based on the enhanced hierarchical decomposition method. Next, the features of axis orbits are extracted by the EHMvFE. Finally, some of the extracted features are input into an extreme learning machine (ELM) for model training, and the effectiveness of the method is verified with the remaining samples. We apply the proposed method to the rotor axis orbit identification case, and the results show that its recognition rate is 98.963%. In comparison experiments with recognition models based on nonlinear dynamics indicators, multivariate signal processing methods, traditional image feature extraction methods, and popular deep learning models, the proposed model shows substantial advantages, verifying the reasonableness and superiority of the proposed method. This study provides a new idea for rotor shaft fault diagnosis, which has significant reference value for promoting the development of intelligent operation and maintenance of industrial equipment.

The Cu–15Ni–8Sn alloy ingot was prepared in the medium-frequency induction melting furnace. The hot extruded alloy was treated by solid solution at 840 °C for 60 min and aging at 400 °C for different times (0 miñ480 min). The effect of aging time on the evolution of the nanophase of Cu–15Ni–8Sn alloy and the strengthening-toughening mechanism were studied. The results show that at the beginning of aging, the alloy undergoes spinodal decomposition, the wavelength of the modulated structure is approximately 3∼7 nm, the ordered phase transformation of D022and L12occurs simultaneously, and the ordered phase size is approximately 5 nm. With the extension of aging time, the modulated structure became coarser, and the wavelength of the modulated structure increased to 5–9 nm. At the same time, the D022ordered phase changed to the L12ordered phase, and a continuous distribution of elliptical discontinuous precipitation appeared at the grain boundary. The ratio of the long and short axes of the discontinuous precipitation was approximately 4.7. In the late aging period, the D022ordered phase was basically transformed into the L12ordered phase, and discontinuous precipitation, which is incompatible with the matrix, extended into the crystal. After 120 min of aging at 400 °C, the hardness, strength, and elongation of the alloy are 105.4 HRB, 839.8 MPa and 9.6 %, respectively. The peak-aging states D022and L12coexist in an orderly phase at the nanoscale, and this nanoscale strengthening phase is completely integrated with the matrix, which improves the strength and toughness of the alloy. The research results can provide support for the development of high-performance copper alloys in the ocean.

Hyperuricemia (HUA) is a widespread metabolic disease marked by an elevated level of uric acid, and is a risk factor for premature death. The protective effect of corn silk flavonoids (CSF) against HUA and its potential mechanisms were explored. Five important apoptosis and inflammation-related signaling pathways were identified by network pharmacological analysis. The CSF exhibited significant uric acid (UA)-lowering activity in vitroby decreasing xanthine oxidase (XOD) and increasing hypoxanthine–guanine phosphoribosyl transferase levels. In a potassium oxonate-induced HUA in vivo, CSF treatment effectively inhibited XOD activity and promoted UA excretion. Furthermore, it decreased the levels of TNF-α and IL-6 and restored pathological damage. In summary, CSF is a functional food component to improve HUA by reducing inflammation and apoptosis through the down-regulating PI3K/AKT/NF-κB pathway.

Tungsten is a strategic metal that is widely used in various fields such as electron communication, aeronautics and astronautics, materials and chemical engineering, due to its special properties. China has the largest reserves of tungsten resources and the largest output of tungsten concentrate in the world, and plays a decisive role in the world tungsten market. In this work, firstly, the reserves and distribution characteristics of tungsten resources in China were summarized, and the production situation of tungsten concentrate in China was reviewed. Based on the gross domestic product per capita (GDP/capita), five different annual GDP growth rates were used to estimate China's tungsten concentrate production in the future. The estimation results suggested that if China's economy continues to grow at the current rate, the accumulative production of tungsten concentrate will exceed current reserves by approximately 2032. Then, from the aspects of process flow, beneficiation equipment and flotation reagents, the beneficiation technology development of different types of tungsten ore in China was also reviewed, including wolframite, scheelite and tungsten-bearing slime. Finally, taking several representative tungsten mines in China as examples, the classic beneficiation technology of different types of tungsten ores was elucidated in detail. Meanwhile, the development direction of tungsten beneficiation technology in the future was put forward, which was of great significance to maintain the superiority of tungsten resources in China.

A survey was conducted to clarify physicians' understanding of the issues surrounding women, menopause, alternative medicine and drug therapy for the treatment of menopause. The survey provided data with regard to physical understanding of menopause treatment options and their primary interaction with patients on this issue.

Pandy's test is used to assess the globulin level in cerebrospinal fluid (CSF). As a semi-quantitative manual method, the practicality and clinical value of Pandy's test has been challenged.

Lime (CaO) and sodium humate (NaHA) were used as the combined depressant for arsenopyrite pre-treated by CuSO4and butyl xanthate. Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite. Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite, for which the Zn grade and recovery of Zn concentrate were 51.21% and 92.21%, respectively. Contact angle measurements, adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species (mainly as Ca2+) were adsorbed on the mineral surfaces, thereby promoting NaHA adsorption. Moreover, the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite, thereby accounting for the strong hydrophilic surface of arsenopyrite. The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms, whereas that on sphalerite surface was relatively weak.

This paper develops an inventory-transport model where demand, lead time and freight loss and damage are all stochastic. An exact formulation, as well as a set of approximations, of a shipper's average logistics cost are derived. They are tested on numerical examples and the results are discussed in terms of the performance of the approximations, the impacts of freight loss and damage, and the relationships between loss and damage control and reductions of the mean and variance of lead time. (Reprinted by permission of the publisher.), I. Introduction The freight rate is only one dimension of transport service. Service quality levels, such as average transit time, transit time variance, and loss and damage (L/D) are also [...]

Environmentally friendly flotation reagent, polyaspartic acid (PAPA), was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite. The depression mechanism of PAPA was revealed by contact angle measurements, Zeta potential measurements, Fourier transform infrared spectroscopy (FT-IR) analysis and inductively coupled plasma (ICP) measurement. The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite, while chalcopyrite remained floatable. Moreover, a concentrate containing 31.40% Cu with a recovery of 92.43% was obtained in flotation tests of artificially mixed minerals. Results of contact angle measurements, Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface, preventing the further adsorption of sodium diethyl dithiocarbamate (DDTC) on its surface. ICP measurements indicated that PAPA had an excellent complexing ability with Cu2+in flotation pulp, weakening the activation of Cu species on sphalerite surface and producing selective depression.

In this research, growing season evapotranspiration of riparian grassland was studied based on micrometeorology data and evaporation data. The mean daily evapotranspiration of grassland during growing season from June to September is 5.8, 4.9, 5.3 and 4.9mm respectively. The 24-h change of grassland evapotranspiration shows a single peak curve, while evapotranspiration occurs during daytime and atmospheric moisture condensation occurs during night. The water circulation process changes from atmospheric moisture condensation to evapotranspiration at about 7:00 from June to September, changes from evapotranspiration to atmospheric moisture condensation at about 20:00 in June and July while at about 19:00 in August and September. The maximum evapotranspiration occurs at 13:00 in June and August while the maximum evapotranspiration occurs at 14:00 in July and September. During daytime, the standard deviation of daily evapotranspiration is large. Soil evaporation is significantly larger than grass transpiration.

At present, most of molecular sieves (MCM-48) are prepared by using dual template agents. In this paper, the effect of different template agents on the synthesis of MCM-48 under the same conditions is studied. MCM-48 was synthesized by different combinations of templates (CTAB + TEAOH, CTAB + TBAB, CTAB + P123). The specific surface areas of them were compared under different crystallization temperature and different crystallization time. The results show that the specific surface area of MCM-48 prepared by CTAB + TEAOH is higher than that of other dual template agnets at the same crystallization time and temperature when the molar ratio of CTAB to another template is 9.

The hydrothermal synthesis of MCM-48 molecular sieves with CTAB and TEAOH as dual template agents and alkaline silica sol as silicon source has been systematically studied. The samples prepared at different crystallization temperature and time were analyzed by XRD, IR, nitrogen adsorption and desorption. The result shows that the best crystallization temperature and time are 100°C and 48h, respectively. According to BJH algorithm, the specific surface area of the sample is 1088 ~ 1669 m2/g, the pore size is 2.48 ~ 2.54 nm, and the pore volume is 1.2064 ~ 1.263 0cm3/g. Because it has high specific surface area, it can be widely used in catalytic adsorption, environmental engineering, biomedicine and other fields. Keywords: MCM-48; mesoporous molecular sieve; high specific surface area; dual template agents; alkaline silica sol

The depression mechanism of zinc sulfate (ZnSO4) and sodium dimethyl dithiocarbamate (DMDC) as the combined depressant on sphalerite was investigated by micro-flotation experiments, ion complexing tests, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis.The micro-flotation tests revealed that ZnSO4+DMDC had a better selective depression effect on sphalerite than using single ZnSO4or DMDC. Ion complexing tests confirmed that DMDC had a strong complexing capacity with lead ions or hydroxy complexes. Contact angle tests illustrated that ZnSO4+DMDC makes the sphalerite surface more hydrophilic than ZnSO4or DMDC. XPS analysis indicated that the combined depressant could prevent collector adsorbing on the Pb-activated sphalerite surface by a competitive adsorption method, while the combined depressant and collector were co-adsorbed on galena surface.

By making a distinction between two kinds of histories, this article attempts to chart the fine line between “actions in the past” and “subsequent records” within the multilayered process of humankind’s practices. One might call “History B” the efforts by later writers to impose some “continuity” onto history, embodying a kind of discursive power; similarly, one might give the name of “History A” to the indelible historical vestiges left by humans who lived in the past. History A constitutes a kind of “counter-power” that constantly challenges existing historiographic discourses. Focusing on the complex yet paradoxical relationship between these two kinds of histories, this article discusses the achievements and pitfalls of contemporary historiography, particularly Chinese.

Hierarchical porous carbon (HPC) was simply prepared through pyrolysis of sodium citrate and further used as modified material for the determination of dopamine (DA) and uric acid (UA). Compared with a conventional glassy carbon electrode, the modified sensor achieved a larger active area and a faster electron transfer rate due to the high specific area and unique hierarchical porous construction. The separate and simultaneous analysis of DA and UA using the modified electrode was carried out by amperometry (AP) and differential pulse voltammetry (DPV), respectively. For separate measurement of each analyte, the linear ranges were 0.027-417 uM and 0.13-806 uM for DA and UA, with the detection limits (S/N = 3) of 0.012 and 0.06 uM, while for simultaneous detection, it exhibited the linear detection ranges of 0.04-100uM for DA and 0.2-100uM for UA, with the detection limits (S/N = 3) of 0.018 and 0.07 uM, respectively. In addition, the sensor is applied to simultaneous detection of DA and UA in spiked samples of juice, milk and urine samples, and satisfactory recoveries were obtained (97.0-104.0%). The results demonstrated that the modified HPC sensor has the advantages of simplicity, sensitivity, and practicality.

BACKGROUND:The objective of current study was to develop and validate a nomogram to predict overall survival in pancreatic neuroendocrine tumors (PNETs). METHODS:The Surveillance, Epidemiology, and End Results (SEER) database was queried for patients with PNETs between 2004 and 2015. Patients were randomly separated into the training set and the validation set. Cox regression model was used in training set to obtain independent prognostic factors to develop a nomogram for predicting overall survival (OS). The discrimination and calibration plots were used to evaluate the predictive accuracy of the nomogram. RESULTS:A total of 3142 patients with PNETs were collected from the SEER database. Sex, age, marital status, primary site, TNM stage, tumor grade, and therapy were associated with OS in the multivariate models. A nomogram was constructed based on these variables. The nomogram for predicting OS displayed better discrimination power than the Tumor-Node-Metastasis (TNM) stage systems 7th edition in the training set and validation set. The calibration curve indicated that the nomogram was able to accurately predict 3- and 5-year OS. CONCLUSIONS:The nomogram which could predict 3- and 5-year OS were established in this study. Our nomogram showed a good performance, suggesting that it could be served as an effective tool for prognostic evaluation of patients with PNETs.

An environment control and life support system (ECLSS) is an important system in a space station because it can provide a basic living environment for astronauts. The ECLSS is a typical time-variant complex system, hence there exits time-consuming technical difficulty during its development. The real-time simulation technology can help to accelerate its research process because some models of complex hardware need not to be built and calibrated at all. For a real-time simulation system with time-varying parameters, an implicit fixed time step numerical integration method is normally used as its solver. However, its computational efficiency is too low especially for the complex ECLSS simulation system on a single personal computer (PC) cluster. An explicit fixed time step integration method is computationally efficient, but their potential instability problems, which are caused by the time-varying parameters, limit its application to the ECLSS system. In this paper, an improved model method based on the explicit Euler method is proposed to simulate the complex time-variant ECLSS on a PC cluster. A simplified ECLSS system is established as an example to explain this proposed method. The eigenvalue estimation theory is used to analyze the numerical stability of the simplified system. Further, the potential instability problem of the explicit method can be avoided by an adaptive operator. Both of the stability and the accuracy of the proposed method are investigated carefully. It can be concluded from simulation results that this proposed method can provide a solution to realize the real-time simulation for the complex time-variant ECLSS on a PC cluster.

To explore genetic differentiation and the genetic relationships of Phytophthora sojae in Anhui Province, the inter-simple sequence repeat (ISSR) technique was used to analyze the genetic diversity of P. sojae. One hundred and sixty ISSR fragments were observed, including 129 (80.6%) polymorphic bands. This suggested that abundant genetic diversity existed among P. sojae in Anhui Province. The pairwise genetic similarity coefficients among the 62 strains ranged from 0.72 to 0.96, with a mean value of 0.85, indicating that there was a high level of genetic variation. Phytophthora sojae strains were divided into five clusters based on neighbor-joining (NJ) analysis, and the clustering was not related to geographic source, according to Mantel's test (r = 0.3938). In addition, the clustering of strains from the same geographical source had little relationship to the year of collection. Analysis of molecular variance (AMOVA) showed that 16.65% of the genetic variation was derived from the collection area and 83.35% of the genetic variation was within-population variation. The genetic flow between different geographical sources ranged from 0.623 to 2.773, with a mean of 1.325, suggesting that gene exchange was frequent. Genetic distance and the genetic differentiation coefficient were not related to spatial distance. [ABSTRACT FROM AUTHOR]

Scenic tourist buildings are the important material security conditions for famous scenic cities to carry out tourism activities, and the level of their planning and design will directly affect the tourists' recognition of the scenic spots. Based on this, a research on the evaluation of the coupling degree between scenic tourist buildings and sites based on analytic hierarchy process was put forward. First of all, the theory of the coupling between the landscape tourism architecture and the site was elaborated, and then the landscape tourism architecture and its planning and design were proposed; taking a certain project as an example, planning and design of its teahouse, villas, sightseeing stand and other buildings were analyzed emphatically; in addition, the evaluation of the coupling degree of AHP was used to show that the planed and designed scenic tourist buildings are in the landscape and they can also be the landscape.

Egg is one of the eight major food allergens, and ovalbumin (OVA) is the most abundant allergenic protein in eggs. In this study, the effects of pulsed electric field (PEF)-assisted Alcalase hydrolysis on the spatial conformation and potential allergenicity of OVA were studied, and the mechanism of its inhibiting allergic reactions effect was revealed. PEF-assisted Alcalase hydrolysis increased the degree of hydrolysis, surface hydrophobicity, and free sulfhydryl group content. Moreover, the reduction in the α-helix content, fluorescence intensity, and disulfide bond content suggested that PEF promoted the OVA hydrolysis by Alcalase. Additionally, enzyme-linked immunosorbent assay data indicated that PEF-assisted Alcalase hydrolysis hindered OVA binding to immunoglobulins E and G1. Finally, based on bioinformatics combined with mass spectrometry, PEF-assisted Alcalase reduced OVA-induced allergic reactions by destroying epitopes in OVA. Overall, PEF technology further destroyed the epitopes of allergens by targeting the binding sites of substrates and enzymes to improve the affinity of enzymes and substrates, reducing allergic reactions.

Physically assisted chemical modifications can effectively reduce the allergenicity of ovomucoid (OVM). However, only a few studies have used pulsed electric field (PEF)-assisted alcalase hydrolysis to reduce the allergenicity of OVM. Herein, we investigated the effect of PEF-assisted alcalase treatment on the spatial conformation, allergenicity, and antigenic epitopes of OVM based on multispectroscopic analyses, bioinformatics, and mass spectrometry. The results showed that PEF-assisted alcalase treatment promoted the hydrolysis of OVM; moreover, the α-helix content and surface hydrophobicity of OVM significantly decreased, which disordered its spatial conformation and weakened its intermolecular interactions. Additionally, enzyme-linked immunosorbent assay (ELISA) results showed that the PEF-assisted alcalase treatment significantly reduced the binding levels of IgE and IgG1, which were 47.66 and 36.41%, respectively. Finally, eight epitopes of OVM were obtained by immunoinformatic tools. Nano-high performance liquid chromatography coupled to tandem mass spectrometry (nano-HPLC MS/MS) results showed that the hydrolysate of OVM and alcalase (HOVM) had nine more peptide-containing epitopes than the hydrolysate of PEF-treated OVM and PEF-treated alcalase (HOVM-PP′), indicating that PEF could promote the elimination of linear epitopes in OVM, thereby reducing OVM allergenicity.

The differing social roles of historians in ancient Greece and in ancient China provide the starting point for this investigation of the specific features of Chinese historiography. The writing and reading of history in China was far from a specialized pursuit: it formed one of the core domains of a generalist practice of scholarship with which not only scholars and writers, but all aspirants to public office, had to be familiar. The twentieth-century reorganization of academic disciplines has partially but not totally obscured the earlier function of historians as advisors and critics of the powerful. Speaking from the vantage point of guoxue, the traditional Chinese interdisciplinary field of literature plus history and philosophy, Liu Dong here advocates a revival of Chinese modes of recording and reliving the past.

Study on civil aircraft emergency evacuation process by using of computer model is an effective way to validate and improve the evacuation performance of aircraft. In this paper, based on the characteristics of the aircraft structure and personnel evacuation, a finer-grid civil aircraft evacuation model (FGCAEM) is built. In this model, the effect of seat area, others and fire products on escape process is considered. Simulations reproduce typical characteristics of aircraft evacuation, such as the movement synchronization between adjacent pedestrians, route choice and so on. It is indicated that evacuation efficiency will be reduced significantly in case of fire, especially in the last period of the evacuation process. Results will be helpful for the design of security auxiliary equipment of airplane and promoting management procedure to emergency case.

AbstractIn the paper, the authors construct three new sequences converging fast to Euler–Mascheroni constant γand obtain a sharp double inequality for bounding the harmonic number.

Baicalin is a major bioactive component of Scutellaria baicalensis and a substrate of multiple drug resistance-associated protein 2. Expression of multiple drug resistance-associated protein 2 is regulated by NF-E2-related factor 2. The aim of this study was to explore whether ursodeoxycholic acid, an NF-E2-related factor 2 activator, could influence the oral bioavailability of baicalin. A single dose of baicalin (200 mg/kg) was given orally to rats pretreated with ursodeoxycholic acid (75mg/kg and 150 mg/kg, per day, intragastrically) or normal saline (per day, intragastrically) for six consecutive days. The plasma concentration of baicalin was measured with the HPLC method. The result indicated that the oral bioavailability of baicalin was significantly and dosedependently reduced in rats pretreated with ursodeoxycholic acid. Compared with control rats, the mean area under concentration-time curve of baicalin was reduced from 13.25±0.24mg/L h to 7.62±0.15mg/L h and 4.97±0.21mg/L h, and the Cmax value was decreased from 1.31±0.03 mg/L to 0.62±0.05mg/L and 0.36±0.04 mg/L in rats pretreated with ursodeoxycholic acid at doses of 75 mg/kg and 150 mg/kg, respectively, for six consecutive days. Hence, ursodeoxycholic acid treatment reduced the oral bioavailability of baicalin in rats, probably due to the enhanced efflux of baicalin from the intestine and liver by multiple drug resistance-associated protein 2. [ABSTRACT FROM AUTHOR]