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In order to further enhance the performance of the AlSi10Mg parts fabricated by selective laser melting, the WC/AlSi10Mg composite with 0.1%WC(mass fraction) was obtained by mixing the nano-WC and AlSi10Mg in mixing machine, and the specimen block was fabricated by the selective laser melting machine. By comparing the AlSi10Mg specimens fabricated by the same process, the effects of nano-WC on the microstructure formation and evolution of the microstructure and the mechanical properties of the microstructure were investigated. The results show that the WC/AlSi10Mg powder has good sphericity and the particle size distribution is concentrated in 20-60 μm. The WC/AlSi10Mg sample has the density of over 99% and hardness of about 158.89HV, which is 14.58% higher than that of the AlSi10Mg sample. The WC/AlSi10Mg samples grow uniformly and densely, with obvious molten pool lines. The inside of the crystal grain is α-Al matrix, and the boundary is a eutectic Si phase interposed with WC. The yield strength of the WC/AlSi10Mg sample reaches 337.75 MPa, the ultimate strength is as high as 514.00 MPa, and the elongation is 3.78%. Compared with the same process, AlSi10Mg samples are increased by 4.73%, 6.25% and 35.97%, respectively. Therefore, SLM-processed WC/AlSi10Mg composite parts have better application prospects than AlSi10Mg parts.

We report on an Er:Y2O3 ceramic channel waveguide laser operating at continuous-wave and passively Q-switched regimes, for the first time to the best of our knowledge. The Er:Y2O3 ceramic channel waveguide has been fabricated by a femtosecond laser direct-writing technique. The maximum output power reached 123.5 mW in continuous-wave mode with a slope efficiency of about 21%, and the lasing behavior has been found simultaneously at 2710.28, 2716.76, and 2723.18 nm. We have further fabricated an MXene Ti3C2Tx saturable absorber mirror to operate the Er:Y2O3 waveguide in passively Q-switched regime. At the same time, property of the MXene Ti3C2Tx saturable absorber has been characterized, and nonlinear saturable absorption of the saturable absorber has also been measured. The average output power is about 67.6 mW, and the shortest pulse width is about 58.1 ns. This work indicates that femtosecond laser direct writing is a reliable technique for processing mid-infrared ceramic waveguides, and MXene Ti3C2Tx is promising for operating pulsed mid-infrared lasers.

Triaxial seepage tests were conducted on the core-wall clay of a high rock-fill dam to investigate the change of hydraulic conductivity with axial strain. It was found that the compaction density and confining pressure were the two main factors influencing the change of hydraulic conductivity during triaxial compression. When the current confining pressure was greater than the pre-consolidation pressure of a compacted specimen, the specimen kept being compressed and became denser during the compression process, resulting in a decreasing trend in its hydraulic conductivity until it eventually reached a stable state. On the other hand, if the current confining pressure was far less than the pre-consolidation pressure of the specimen, the specimen deformed in a localized shear band which weakened the impermeability of the specimen, and as the shear band continued to dilate, an increasing trend in the overall hydraulic conductivity was observed. This study highlighted an important fact that heavily compacted clay under low confining pressures had a high susceptibility to localized shear bands of high permeability, which could be used to explain many historical leakage problems observed in clay-core dams.

In high rockfill dam, particle breakage is one of the main factors that lead to dam deformation. However, because of the large size of the rockfill particles, the breakage degree of the prototype rockfill materials is difficult to be measured directly through laboratory test. Therefore, the common practice is to reduce the size of the prototype gradation particle to less than 60 mm before the laboratory test can be carried out. However, due to the significant difference between the prototype and the test gradation, the parameters measured in the test are often quite different from the actual parameters of the prototype rockfill materials, thus affecting the in-depth study of the mechanical properties of the prototype rockfill materials. In this paper, a new method is proposed to describe the change of particle size distribution (PSD). Firstly, based on the theory of Weibull distribution of the particle strength and fractal crushing of the particle, the calculation of PSD change of the original rockfill materials is elaborated. Then, the relevant parameters are obtained by conducting the single-particle crushing test, and by comparing with the triaxial test, the rationality of parameter selection is verified. Moreover, the effects of the discrete degree of particle strength on the shape of the PSD is analysed. Finally, the relationship between the relative crushing parameters and stress state of the rockfill materials during loading is discussed.

The optimization of park green space landscape pattern is of great significance to the construction of an ecological civilized city. Through a case study of the national garden city – Mianyang City, Sichuan Province – and with the help of analysis softwares such as ENVI and ArcMap, the public green space landscape pattern in the central urban area has been quantitatively analyzed in terms of Normalized Vegetation Difference Index (NVDI) and landscape pattern index, and corresponding optimization strategies have been proposed. It is found out that: 1. NVDI in Fucheng District presents a growing trend from the perspective of spatial distribution characteristics, although the balance of NVDI increased significantly. 2. Urban park green space is highly fragmented under city scale, and the park green space landscape is featured by small patches and medium-sized and large scale coexisting. 3. Spatial distribution of park green space landscape types in Fucheng District is badly imbalanced and landscape structures are unreasonable 4. Calculation and analysis of landscape pattern index show the small patches in Fucheng District are highly spatially heterogeneous and fragmented with a large patch shape index. This paper aims to provide reference for the planning and construction of an urban park green space landscape.

Focusing on the energy efficiency (EE) improving problem in a densely deployed cellular network with partial conventional base stations (BSs) that cannot be frequently switched on/off, this paper jointly optimizes the switching on/off strategy and user association policy with the consideration of quality-of-service (QoS). By applying a modified switching cost model, we formulate the EE improving problem as an energy efficiency maximization problem (EEMP). To solve the EEMP efficiently, we first concentrate on the EEMP with a constant user distribution where switching cost is omitted temporarily, i.e., static- EEMP, and then the EEMP can be settled by using the results of the static-EEMP. After analyzing the hardness of solving the static-EEMP directly, several sub-optimal strategies are proposed for the static-EEMP to optimize the BSs working states and user association policy. With the results obtained from solving the static-EEMP, we propose a QoS First Maximum EE (QFMEE) scheme to solve the EEMP in two steps. In the first step, necessary BSs are switched on when the user distribution changes to ensure user QoS. In the second step, we judge the extra cost and the energy saving caused by the switching off operations to improve the network EE. Simulation results verify the effectiveness of our proposed strategies for static-EEMP and show that QFMEE can improve the network EE and reduce switching cost significantly when the switching cost occupies a considerable proportion in the total energy consumption.

In this paper, the bifurcation and chaotic motion of a piecewise Duffing oscillator with delayed displacement feedback under harmonic excitation are studied. Based on the Melnikov method, the necessary critical conditions for the chaotic motion in the system are obtained, and the chaos threshold curve is obtained by calculation and numerical simulation. The accuracy of the analytical result is proved by some typical numerical simulation results, including the local bifurcation diagrams, phase portraits, Poincaré maps, and the largest Lyapunov exponents. The effects of excitation frequency and time delay of the displacement feedback are analytically discussed. It could be found that the critical excitation amplitude will increase obviously with the increase of the excitation frequency, and under the selection of certain parameters, the critical excitation amplitude takes the time delay of 0.58 as the inflection point, which decreases at first and then increases.

Chemistry is an experimental science. Practical teaching is a significant link in the cultivation of students majoring in chemistry to foster students' practical, professional application, and innovation abilities. Based on the investigation and analysis of the problems existing in the cultivation of the practical ability of applied chemistry major, take specific measures, such as constructing the practical teaching system of applied chemistry major, explored a better practical teaching system for students of applied chemistry major; applied to the reform and innovation of training mode of students majoring in applied chemistry and achieved good results.

Four diode-type gyrotrons are used in the EAST ECRH system now. The anode is one of the main components of the gyrotron. We can control the output power of the gyrotron by changing the anode voltage. An anode voltage control system for ASIPP anode power supplies was developed based on the ethernet CompactDAQ chassis NI-cDAQ-9185. The anode voltage can be controlled up to 30 kV, and the maximum current is 100 mA. The maximum modulation frequency is 5 kHz at a 50% duty cycle.

Introduction As people age, they are more likely to experience a decline in their response inhibition ability, which interferes with daily life. Previous studies have shown that exercise intervention can improve the cognitive ability of the elderly, but research on open-skill and closed-skill exercises to improve the response inhibition in this age group is still limited. This study will explore the advantages of long-term intervention of table tennis (open-skill exercise) compared with fit aerobics (closed-skill exercise) on the response inhibitory ability of the elderly.Methods and analysis A single-blind randomised controlled trial will be conducted. A total of 90 elderly subjects will be recruited and allocated randomly to the following groups: table tennis, fit aerobics and control. The interventions for the table tennis group and the fit aerobics group will be implemented in three 60 min sessions per week for 6 months; the control group will receive no exercise intervention. The primary assessment will be behavioural indicators of response inhibitory ability in the elderly based on the stop signal task. The secondary outcomes will include cognitive ability, mental status and depression in the elderly. Assessments will be conducted at baseline, 3 months, 6 months and 12 months.Ethics and dissemination This study was approved by the Shanghai University of Sport Research Ethics Committee (102772019RT012) and will provide reference for the advantages of table tennis compared with other types of sports in improving the response inhibitory ability of the elderly. The results of this study will provide a theoretical basis for choosing the best exercise programme to improve the response inhibitory ability of the elderly.Trial registration number This study has been registered prospectively in the Chinese Clinical Trial Registry (ChiCTR2100043616, 23 February 2021).

In this paper we consider the nonlinear Chern-Simons-Schrödinger equations with general nonlinearity

For the high power solar array simulator, the requirements such as high power, miniaturization and modularization are higher. In this paper the total power of the simulator is 2.4 kW with the chassis height is no more than 2U. The forced air cooling is adopted. The modular structure is used in the forced cooling system according to the electrical connection requirement. The chassis is divided into three parts, the linear, the multilevel and the Vicor module. And the independent cooling air duct system is set up for each part. The contractile air duct of the multilevel and the Vicor part are optimized mainly. The forced air cooling system with the optimization design can satisfy the high power density requirements of the simulator. The maximum case temperature of the components can be controlled under 88 ℃, and all the devices in the simulator can work safely and reliably. The results are verified by both finite element simulation and thermal test.

BACKGROUND The oxygen isotopic composition of sulfate radical in mineral or water can be used to identify the source and transformation process. At present, the common method is to convert sulfate radical into barium sulfate and the oxygen isotopic composition determined offline or online. It is possible to shorten the working life of the furnace when δ18O of barium sulfate is measured online under 1420℃. The reaction temperature can be reduced by adding reductant carbon, but there is less discussion about the reaction temperature reported. OBJECTIVES To confirm the key technical parameters during determination of oxygen isotope composition in barium sulfate online. METHODS Nickel-plated carbon was added in a series of conditional experiments during determination of oxygen isotope composition of barium sulfate by elemental analysis/isotope ratio mass spectrometry (EA-IRMS). RESULTS 1350℃ was chosen as the online pyrolysis temperature of barium sulfate by adding Ni-C. The sample size ratio between Ni-C and BaSO4 was set as 0.73-2.15. The sample weight of Ni-C and BaSO4 was 700±100μg, respectively. Under the above conditions, the precision of δ18O of BaSO4 measured by EA/HT-IRMS was ±0.12‰-±0.26‰, better than the reported results of ±0.20‰-±0.50‰. CONCLUSIONS On the premise of better precision, the online pyrolysis temperature of barium sulfate can be reduced to 1350℃ and the lifetime of the reactor can be improved by adding Ni-C.

BACKGROUND As the world's largest producer of synthetic diamonds, China accounts for more than 90% of the world's total production, of which high pressure-high temperature (HPHT) synthetic diamonds are dominant. Previous scholars have conducted many studies on analytical methods and property analysis of HPHT synthetic diamonds. However, the research on the pickling process after the growth of HPHT synthetic diamonds and the internal and external micro-structures after pickling is still insufficient. OBJECTIVES To characterize 118 synthetic diamonds produced in China by high temperature and high pressure method. METHODS The HPHT synthetic diamonds were observed by laser scanning confocal microscopy (LSCM) and ultra-depth-of-field 3D microscopy, and the dark inclusions in these micro-structures were qualitatively analyzed by laser Raman spectroscopy. RESULTS Three structure types were found. Step-like growth structures with certain angles revealed the crystallographic characteristics of HPHT synthetic diamond poly-crystals. Near-parallel linear scratches reflected the contact relationship between diamond grains in the growth chamber. The 'rope-tied' structures reflected the growth rate of HPHT synthetic diamonds. CONCLUSIONS The micromorphology of these diamond surfaces reflects the growth conditions and environment of HPHT synthetic diamond gradient high temperature and continuous high pressure, which is of significance for the identification of HPHT synthetic diamonds.

Objective To explore the effects of clinicopathological features and adjuvant therapy on the prognosis of patients with poorly-differentiated gastric neuroendocrine tumors. Methods We retrospectively analyzed 124 cases of gastric neuroendocrine tumors treated with radical surgery. The neoplasms were classified into different types, grades and stages according to the standard of classification. Follow-up was conducted. The survival curves were drawn by Kaplan-Meier method. Univariate analysis was performed by Log rank test and multivariate analysis was conducted by Cox proportional hazards model. Results The 5-year survival rates of gastric neuroendocrine tumor, gastric neuroendocrine carcinoma and gastric mixed adenoneuroendocrine carcinoma patients were 100%, 52.4% and 38.8%, respectively. Multivariate analysis showed that lymph node metastasis (P=0.030) and adjuvant therapy (P=0.017), especially cisplatin combined with etoposide regimen (HR=0.051, P=0.015) were independent prognostic factors for patients with gastric neuroendocrine carcinoma; while lymph node metastasis, distant metastasis, TNM stage and adjuvant therapy were not independent prognostic factors for patients with mixed neuroendocrine carcinoma. Conclusion The prognosis of patients with gastric neuroendocrine carcinoma is related to lymph node metastasis and adjuvant treatment, and cisplatin plus etoposide regimen is a reasonable choice for adjuvant treatment.

In order to begin an approach to the structure of arbitrary Lie color triple systems, (with no restrictions neither on the dimension nor on the base field), we introduce the class of split Lie color triple systems as the natural generalization of split Lie triple systems. By developing techniques of connections of roots for this kind of triple systems, we show that any of such Lie color triple systems T with a symmetric root system is of the form T = U + ∑[α]∈Λ1/∼ I[α] with U a subspace of T0 and any I[α] a well described (graded) ideal of T, satisfying {I[α], T, I[β]} = 0 if [α] ≠ [β]. Under certain conditions, in the case of T being of maximal length, the simplicity of the triple system is characterized.

In order to further enhance the performance of the AlSi10Mg parts fabricated by selective laser melting, the WC/AlSi10Mg composite with 0.1%WC(mass fraction) was obtained by mixing the nano-WC and AlSi10Mg in mixing machine, and the specimen block was fabricated by the selective laser melting machine. By comparing the AlSi10Mg specimens fabricated by the same process, the effects of nano-WC on the microstructure formation and evolution of the microstructure and the mechanical properties of the microstructure were investigated. The results show that the WC/AlSi10Mg powder has good sphericity and the particle size distribution is concentrated in 20-60 μm. The WC/AlSi10Mg sample has the density of over 99% and hardness of about 158.89HV, which is 14.58% higher than that of the AlSi10Mg sample. The WC/AlSi10Mg samples grow uniformly and densely, with obvious molten pool lines. The inside of the crystal grain is α-Al matrix, and the boundary is a eutectic Si phase interposed with WC. The yield strength of the WC/AlSi10Mg sample reaches 337.75 MPa, the ultimate strength is as high as 514.00 MPa, and the elongation is 3.78%. Compared with the same process, AlSi10Mg samples are increased by 4.73%, 6.25% and 35.97%, respectively. Therefore, SLM-processed WC/AlSi10Mg composite parts have better application prospects than AlSi10Mg parts.

The spherical and dense alumina nanoparticles were used to prepare alumina microcrystalline ceramics. The effect of granulation and sintering parameters on the microstructure and mechanical properties of the ceramics was studied. The results show that fine green body can be obtained with the addition of 0.8% (mass fraction) PVA, and the density of green body can also be improved. With the increase of sintering temperature from 1400℃ to 1550℃, the density is increased from 74.1% to 97.5%, while the grain size of the ceramics is only increased gradually from 0.6 μm to 1.4 μm owing to the stable spherical shape and the uniformly packed pores. With the increase of holding time from 30 min to 120 min at 1550℃, the porosity is decreased from 4.8% to 0.4%, and the grain size is then increased from 1.2 μm to 2.7 μm. Besides, the sintering activation energy of the employed spheres is 788 kJ/mol, which proves that the particles are inactive during earlier and medium stage of sintering, and the spheres are benefit to obtain microcrystalline ceramics. The ceramic sintered at 1550℃ for 90 min has a density of 98.9%, an average grain size of 1.6 μm, a hardness of 26.4 GPa and a bending strength of 574 MPa.

A simple synthetic method of poly(hexamethylene guanidine hydrochloride) grafted hollow nano-silica (HSN-PHMG), a novel antibacterial material, was proposed. The water dispersibility and antibacterial property of HSN grafting of PHMG were improved. The hollow structure of nano-silica was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis were used to characterize the successful grafting of PHMG and the mass fraction of PHMG is about 9.5% in HSN-PHMG. Antibacterial test using Escherichia coil (E.coil) and Staphylococcus aureus (S.aureus) as test strains and the results show that the minimum inhibitory concentration (MIC) of HSN-PHMG on E.coil and S.aureus are all 32 mg/L; E.coil can be completely killed within 2 h when the concentration of HSN-PHMG is 64 mg/L.

Objective To compare the case-fatality rate (CFR) and relapse rate (RR) between patients with pregnancy-associated breast cancer (PABC) and non-PABC and explore the possible factors contributing to such differences. Methods We searched the online databases including PubMed, CNKI, Wanfang, and VIP for case-control or cohort studies describing the outcomes of patients with breast cancer diagnosed during or within 1 year after pregnancy. The Newcastle-Ottawa Scale (NOS) was used for literature quality evaluation. The odds ratio (OR) and 95% confidence interval (95% CI) were calculated using RevMan5.3, and the publication bias of the retrieved articles was evaluated. Results We retrieved 23 articles that compared the CFR between patients with PABC (n=1 999) and non-PABC (n=13 271). The results of meta-analysis showed that the patients with PABC had a significantly higher CFR than those with non-PABC (OR=1.46, 95% CI: 1.31-1.63; P=0.40, I 2=5%). Meta-analysis of 5 articles that compared the RR between patients with PABC (n=188) and non-PABC (n=493) showed that the patients with PABC had a significantly higher RR than those with non-PABC (OR=2.10, 95%CI: 1.45-3.04; P=0.30, I2=18%). The funnel plots indicated no publication bias in all the articles included in this analysis. Conclusion The patients with PABC have a poorer prognosis than those with non-PABC.

Two bicrystal specimens containing high angle grain boundary (about 20 degrees) were prepared by seed crystal method. The effect of Hf on the as-cast, heat-treated grain boundary microstructure, composition and stress rupture properties under 1100℃/100MPa was investigated in Ni-based single crystal superalloy contained Re with different contents of Hf (mass fraction:0%, 0.4%). The results show that Hf addition results in the increase of the volume fraction of (γ+γ') eutectic and MC along the grain boundary. The volume fraction of cellular recrystallization microstructure is significantly decreased after heat treatment with Hf addition. The transverse stress rupture life is observed to increase significantly under 1100℃/100MPa in the Hf-containing alloy. The stress rupture properties are closely related to the type, morphology, content and composition of the precipitation phase along grain boundary, but the obvious segregation of Hf is not observed. This study can be helpful for the understanding of Hf's role of strengthening mechanism in grain boundary in advanced Ni-based single crystal superalloy.

The actual combustion rate of pulverized coal in the blast furnace tuyere is hard to be measured. In this research, the combustion rate of pulverized coal injected into oxygen blast furnace was obtained by a new equipment. This equipment can simulate the actual blast furnace well, and the relationship between pulverized coal injection (PCI) ratio and AO/C was established by mathematical deduction. The experimental results show that the best combustibility of the four pulverized coals is C, and when the coal injection ratio is 350 kg/tHM, the combustion rate can be reached 79%, while the combustion rate of B in the same case is only 45.6%. With the increase of AO/C, the relative amount of oxygen to coal increases, the combustion conditions become better, and combustion rate of the pulverized coal increases. In addition, under the condition of high temperature and rapid combustion, with the increase of coal’s volatile, the combustion rate increases and the corresponding PCI ratio is also increased. By using the new equipment, the unburned coal under the oxygen blast furnace conditions can be collected for further study.

In this paper, a blast furnace gas flow distribution model with variable furnace structure was founded based on CFD (computational fluid dynamics) theory, and the gas velocity distribution near the surface of the copper staves in different areas of the BF is calculated under different conditions of variational structure parameters like Bosh angle, shaft angle, and the newly proposed “equivalent Bosh angle.” Based on the calculation, the influence rule of the BF structure on the service life of copper stave and the corresponding operation measures were obtained. The result shows that the increase of the Bosh angle and the decrease of the shaft angle will incur increasing of the gas flow velocity near the surface of the copper staves, which is harmful to the cooling stave life; the variation of the equivalent Bosh angle has a most significant influence on the cooling stave life, and the increase of the equivalent Bosh angle will cause a sharp increase of the gas flow velocity, which will damage the copper staves seriously; adopting long tuyeres and minishing the equivalent Bosh angle will reduce the washing action of the gas flow and ensure the stability of slag hanging to achieve a long service life of copper staves.

BACKGROUND Overgrowth diamond refers to the product of thick CVD synthetic diamond layer grown on a natural diamond with the whole appearance. Since overgrown diamonds contain information on the nitrogen impurities of natural diamonds, traditional synthetic diamond screening methods and testing procedures are no longer applicable to the detection of overgrown diamonds. OBJECTIVE To gemologically test an overgrowth diamond sample in order to investigate the full identification features and to propose the optimum detection strategy. METHODS Minspecting, screening instruments testing, UV-Vis/FTIR/PL spectra examinations, as well as fluorescence and phosphorescence observation under deep UV excitation are carried out. RESULTS The sample cannot be identified by traditional microscopic observation, diamond instrument screening, and infrared spectra measurement. The sample has a distinct boundary that is separated by different luminescence under DiamondViewTM. The upper layer displays red fluorescence and greenish blue phosphorescence, while the lower layer shows deep blue fluorescence and no phosphorescence. Infrared spectroscopic analysis shows that the upper layer is type Ⅱa and the lower layer is type Ⅰa diamond. The UV-Vis absorption and photoluminescence spectra confirmed the coexistence of N3 centers and a high level of[Si-V]- defects in the diamond. CONCLUSIONS It was confirmed that the lower part of the sample is natural and the upper part of the sample is CVD synthetic layer with a thickness around 740μm. The first overgrowth diamond reported domestically was compared to the same type of samples reported abroad. The existence of a boundary are missing and the thickness of the CVD layer increased significantly in this sample. The innovative application of the multidirectional luminescence imaging and spectroscopic analyses is the key to laboratory testing of overgrowth diamond.

BACKGROUND Reagent purification, sample pretreatment, environmental humidity, reactor cleanliness and experimental quality control are the main influence factors for determination of oxygen isotopic composition of silicates and oxide minerals by BrF5 method. OBJECTIVES To determine the optimal experimental conditions and improve the accuracy by selecting silicates and oxide minerals as laboratory raw materials for oxygen isotopic composition analysis. To discuss the influence factors for determination of oxygen isotopic composition of silicates and oxide minerals by BrF5 method. METHODS Using BrF5 analysis method and taking standard sample as the reference, oxygen isotopic compositions of silicates and oxide minerals were determined at different calcination temperatures. At the same time, the effects of environmental humidity and reactor cleanliness on the analytical results were also studied. RESULTS The results show that 650-750℃ is the best calcination temperature range for removing carbon components during oxygen isotope analysis, which can avoid the isotope fractionation caused by temperature. By reducing the relative environment humidity or the sample loading time within 0.5min, the lower δ18O values caused by vapor was improved. The new reactor, or the reactor with large yellow substance falling off, or the contaminated reactor will reduce the yield of oxygen and cause oxygen isotope fractionation, so the reactors should be fluorinated or purged in time. The sample and standard material is loaded alternately for each reactor to monitor the reliability of the isotopic composition of the sample. The results of oxygen isotopic composition of GBW04409 are consistent with the recommended values. The relative standard deviation is better than 0.1‰ for δ18O under the optimized conditions. CONCLUSIONS The proposed method can effectively control oxygen isotope fractionation and improve the applicability of BrF5 oxygen isotope analysis method.

Presently, condition monitoring and fault diagnostics in the three-phase voltage-source inverter (VSI) system are already considered essential to improve maintenance efficiency and increase reliability levels. This paper presents a new open-switch fault real-time diagnosis method in the VSI based on the phase currents. First, on the basis of real-time measured two phase currents, the sum of the absolute value of the normalized phase currents is calculated, whose average value is less relevant to the transient condition such as load variations and current frequency variations. Second, the current zero-cross detection method is employed to avoid the influence of current distortion caused by the transient condition. Then, the fault detection signal is built to precisely localize the faulty switches, and the real-time fast diagnosis for three-phase VSI with the open-switch fault is realized. Finally, the experiment results verify the reliability and effectiveness of the proposed method.

The cloud radio access network (C-RAN) with mobile edge computing (MEC) structure which consists of a baseband unit (BBU) pool integrating with an MEC server and several remote radio heads (RRHs) beside the mobile terminals can help users with computational resource-intensive tasks and bring extra profits to network operator at the same time. This paper presents a novel task-aware C-RAN with MEC structure and formulates a profit maximization problem by jointly optimizing offloading strategy, radio and computational resources allocation under the constraints of offloading latency, fronthaul capacity along with limited bandwidth and computational resource. To solve this NP-hard optimization problem in a distributed and efficient way, we propose a spectrum efficiency (SE)-based joint optimization for offloading and resource allocation (SJOORA) scheme which decomposes the original problem into two sub-problems. A SE-based offloading strategy is proposed with confirmed resource allocation, and on the other hand, bandwidth and computational resource allocation problem is solved by using a Lagrangian multiplier method with predetermined offloading strategy. Finally, by solving these two sub-problems iteratively, a suboptimal solution is obtained for the original problem. The simulation results show that the proposed SJOORA scheme can effectively increase the profit of network operator with relative lower complexity.

Fermentation of available sugars in milk by yogurt starter culture initially and later by Saccharomyces boulardii (Probiotic yeast) improves the bioavailability of nutrients and produces bioactive substances and volatile compounds that enhance consumer acceptability. The combination of S. boulardii, a unique species of probiotic yeast, and inulin, an exopolysaccharide used as a prebiotic, showed remarkable probiotic and hydrocolloid properties in dairy products. The present study was designed to study the effect of fermentation and storage on antioxidant and volatile capacities of probiotic and synbiotic yogurt by incorporation of S. boulardii and inulin at 1%, 1.5%, and 2% (w/v), compared with the probiotic and control plain yogurt. All samples were stored at 4 °C, and during these four weeks, they were analyzed in terms of their antioxidant and volatile compounds. The synbiotic yogurt samples having inulin and S. boulardii displayed significantly higher DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical activity values and more values of TPC (total phenol contents) than control plain yogurt. A total of 16 volatile compounds were identified in S5-syn2 and S4-syn1.5, while S3-syn1 and S2-P had 14, compared with the control S1-C plain yogurt samples, which had only 6. The number of volatile compounds increased with the increasing concentration of inulin throughout the storage period. Therefore, this novel synbiotic yogurt with higher antioxidant and volatile compounds, even with chilling storage conditions, will be a good choice for consumer acceptability.

BackgroundMn bath method is one of the most commonly used methods to measure the intensity of radionuclide neutron sources in the world.PurposeThis study aims to guarantee the accuracy of numerical transmission and give a reasonable parameter range during the design of manganese bath device.MethodsFirst of all, Monte Carlo N–Particle Transport Code System (MCNP) was employed to calculate the correction factors, solution concentrations and Mn-bath sphere. Then, a reference device of Mn bath measurement was setup according to the MCNP calculation results, and applied to the measurement of 12 neutron sources located in the standard of thermal neutron fluence rate with International Comparison of neutron sources.ResultsSimulation results show higher ratio of total neutron absorption and manganese neutron capture is obtained when the solution concentration is 17.3%~38.6% in which the uncertainty of neutron-escaping and section ratio is reduced, and the radius of Mn-bath sphere is 45~60 cm in which the volume specific activity of solution is increased and neutron-escaping is decreased. When the number of input particles is up to 100 000, the values of correction factors remain stable, hence the statistical fluctuation can be ignored. The international comparison of neutron sources for the measurement of 12 neutron sources indicates consistent results with the reference values within the uncertainty range.ConclusionsThe parameters range of this study provides an effective reference for the establishment of Mn bath device in the future.

The cost of growing triploid watermelon seedlings has increased due to their low-efficiency grafting. The first priority in growing seedless watermelon seedlings is increasing the grafted-plant and seed-utilization rates. This study aimed to improve the grafted-plant rate by screening the most suitable substrate formulation, optimizing water moisture in the substrate, and evaluating the effect of different scions to improve seed-utilization rate. Five combinations of substrate (S1 to S5) and seven relative humidity levels (45%, 50%, 55%, 60%, 65%, 70%, and 75%) were used. Three types of scions (yellow bud, Ts-1; two cotyledons did not unfold, Ts-2; and first true leaf appeared, Ts-3) were tested. Results showed that the combination of S1 exhibited the best seed-utilization rate which was 71.6%. Moreover, the most suitable water moisture in the substrate ranged from 50% to 55%. The usage of the scion from Ts-3 significantly increased the grafting survival, grafted plant and seed-utilization rates by 13.7%, 10.1% and 22%, respectively, compared with the conventional method. Our study suggested that the best time to use the scion and the rootstock was during the seedling stage when the first true leaf unfolded. The proposed method decreased the production cost of seedlings and significantly improved the efficiency of grafting procedures. The results of this work are applicable to the technique of growing seedlings and can thus guide growers of high-quality grafted plants of triploid watermelon.