Search

Background We aimed to explore the relationship between body mass index (BMI) and body weight perception (BWP) with suicidal behaviors among mainland Chinese adolescents. Methods A nationally representative sample (N = 10 110) of Chinese adolescents was assessed in this study. Suicidal behaviors (ideation, plan and attempt) were evaluated by four self-reported questions. Generalized linear mixed model was used to estimate the adjusted odds ratios (ORs) for the association between BWP/BMI with suicidal behaviors. Results The prevalence of suicidal ideation, suicidal plan and suicidal attempt was 12, 5 and 2.1%, respectively. After adjusting potential covariates, perceiving oneself as obese was significantly associated with increased risks of suicidal ideation (OR: 2.4, 95% confidence intervals, CI: 1.6–4.0, P = 0.001), suicidal plan (OR: 3.1, 95% CI: 1.5–6.3, P = 0.002) and suicidal attempt (OR: 3.7, 95% CI: 1.5–9.1, P = 0.001) compared with perceiving as normal weight among male adolescents; the effect attenuated to null among female adolescents. Perceiving oneself as underweight and overweight both exhibited significant adverse effect on suicidal behaviors (only suicidal ideation and suicidal plan) compared with perceiving oneself as normal weight among male adolescents, but not among female adolescents. The actual measured BMI was not significantly associated with suicidal behaviors among neither gender. Conclusions Self-perception of their body image rather than actual measured weight may have a gender-specific adverse effect on suicidal behaviors among Chinese adolescents.

It is highly desirable to red shift the emission of Y3Al5O12:Ce3+ phosphor to obtain a warmer correlated color temperature (CCT) in applications for blue-light pumped white-light emitting diodes (w...

This paper performs a Monte Carlo CLEAN (MC-CLEAN) spectral analysis with high-resolution electrical image log data and interpret the high-resolution formation sequence by investigating the cycles in the sediments. Firstly, in order to perform a spectral analysis with high-resolution electrical image log data, the background conductivity log curve was extracted from the borehole image. Secondly, the MC-CLEAN spectrum analysis method was used to isolate all the peaks of the logging signal. Then the 95% significance level of the CLEAN spectrum was calculated to identify the true period of the formation by Monte Carlo simulation. Finally, the MC-CLEAN spectral analysis method was applied in the two shale intervals from Lower Pannonian interval of Vienna basin to identify the stratigraphic cycles. The analysis results showed that the identified cycles in the sedimentary record good matched the Milankovitch cycles. This paper provided a new approach of identifying stratigraphic cycles and interpreting high-resolution sequence stratigraphy.

Like micro-silica (MS), nano-silica (NS) can also be considered as a supplementary cementitious material for production of high-performance mortar and concrete. To investigate the influence of MS and NS on the fresh properties of mortar or the mortar phase of concrete, an experimental program encompassing mortar mixes with various water, cement, MS and NS contents was launched for undergoing flowability, cohesiveness and adhesiveness measurements. It was found that the NS added, albeit at much smaller dosage, has greater effects than the MS added on the fresh properties of mortar. More importantly, NS has negative effects on flowability, but positive effects on cohesiveness and adhesiveness. These results suggest that by enhancing the cohesiveness and adhesiveness, the addition of NS in conjunction with MS is a promising method for producing mortar with high adhesiveness requirement, as reflected by the results of the newly developed stone rod adhesion test.DOI: http://dx.doi.org/10.5755/j01.ms.23.4.16632

A series of luminescent Ba0.79Al10.9O17.14:xEu (x = 0.005–0.12) phosphors were prepared by high-temperature solid-state reaction in air atmosphere. The coexistence of Eu2+ and Eu3+ was observed and verified by photoluminescence (PL) and photoluminescence excitation (PLE) spectra, X-ray photoelectron spectra (XPS), and diffuse reflection spectra. The band emission peaking at 430 nm was assigned to 4F65D–4F7 transition of Eu2+, and another four emissions peaking at 589, 619, 655, and 704 nm were attributed to 4F–4F transitions of 5D0–7F J (J = 1, 2, 3, 4) of Eu3+. The related mechanism of self-reduction was discussed in detail. The color of the Ba0.79Al10.9O17.14:xEu phosphors could be shifted from blue (0.23, 0.10) to red (0.42, 0.27) by doping Li+ ions, and the temperature dependence properties were investigated.

An Ag/AgBr/Bi5O7I heterojunction was developed using a simple in situ co-precipitation method. Ag/AgBr nanoparticles were tightly bound to Bi5O7I, improving charge transfer at the heterojunction interface. The photocatalytic activities of the Ag/AgBr/Bi5O7I composites were studied by monitoring the photodegradation of Rhodamine B (RhB) and through the generation of a transient photocurrent under visible-light irradiation (λ > 420 nm). The Ag/AgBr/Bi5O7I composites displayed enhanced photocatalytic activities compared to either pure Ag/AgBr or Bi5O7I. Charge carrier behavior was investigated using electrochemical impedance spectroscopy (EIS) which indicated the enhanced separation and transfer of photogenerated electrons and holes, thus giving to the higher photocatalytic activity. The high-performance semiconductor heterojunction developed in this work is a good candidate for photocatalytic application.

Sialon-SiC composite powders were synthesized from kyanite tailings through the carbothermal reduction nitridation (CRN) technique. Using Sialon-SiC composites to substitute Si3N4 composites via the CRN technique synthesize Sialon/Si3N4-SiC composite refractories. The phase composition, cross section morphology, and the substituent amount of Sialon-SiC composites impact on refractories mechanical properties were investigated, respectively. The optimized synthesis temperature for the CRN reaction was found to be 1550 °C for 4 h with the excess carbon 20%. The substituent amount of Sialon-SiC was 25%, the mechanical properties of Sialon/Si3N4-SiC composite refractories reached optimal performance, which bending strength value was 41.8 MPa and compression strength value was 61.6 MPa.

ZrO2 fibers and belts have been fabricated by heat-treating the hybrid fibers and belts which were prepared by electrospinning method. Fiber and belt properties, for instance, surface morphology, diameter of fibers, crystallization formation, etc. were investigated by various techniques, scanning electron microscopy (SEM), X-ray diffractometer (XRD), transmission electron microscopy (TEM), energy dispersive spectrum (EDS) included. It was found that more belts and thicker fibers appeared with increasing PVP content. Using N,N,N-trimethyl-1-dodecanaminium bromide (DTAB) can avoid formation of belts and reduce the diameter of fibers from a range of 270 to 750 nm to a range of 90 to 150 nm. It all obtained monoclinic ZrO2 fibers and belts after heat-treating (respectively at 700, 800, 900 °C) hybrid fibers and belts. The higher temperature heat-treatment leads rougher fibers and belts.

Density logging is a very important method of nuclear logging, which is mainly exploring the density of rock bed through study the pore structure of reservoir and commonly employed in petrol geophysical exploration. It’s very important in density logging to study the effects of borehole conditions which can be helpful in developing instruments and improving the exploring efficient. This paper studied the response of high rank anthracite reservoir at the situation of borehole enlarging via MCNP.

Super-grade bauxite, pure silicon carbide, andalusite and metal silicon were used as the raw materials to produce plastic phase mullite-SiC bricks. By analysis of the microstructure, physical and chemical properties, it proves that the introduction of metal plastic phase can improve the properties of bricks, such as lower porosity, higher cold crush strength, and wearing resistance. It also can improve the toughness, and effectively relieve the thermal and mechanical stress when using in cement kilns. By analysis of the comparison with MA spinel bricks and ordinary mullite-SiC bricks, the plastic phase mullite-SiC bricks have good thermal shock resistance and lower thermal conductivity. The result shows that the bricks can replace MA spinel bricks using in the transition zone of cement kilns and realizes the aim of saving energy and a long service life.

Cordierite samples were prepared using quartz sand tailings, industrial alumina and magnesite tailings as raw materials by high-temperature reaction. The influence of mineral composition and sintering temperature on the final phase composition and physical properties of cordierite were studied. The results shown that a large number of cordierite generated at 1300 °C. When the ratio of Al2O3/SiO2 equals to 1.08, the flexural strength of samples increased to 27.66 MPa.

Mullite material was prepared from quartz (SiO2) and industrial alumina (γ-Al2O3). The effects of mineral composition and sintering temperature on the final phase composition and physical properties of mullite were investigated. The results shown that a large number of mullite phase was emerged in samples when the ratio of alumina to silica (A/S) was 2.55. At 1500 oC and 1600 oC, the flexural strength of the samples reached to 87.13 MPa and 89.50 MPa, respectively. Consider the environmental protection and energy saving, the optimal sintering temperature was 1500 °C.

The performance and phase behavior of Quartz - Aluminum Matrix Composites at different temperatures were studied. Quartz aluminum matrix composites were prepared by powder metallurgy method. At the temperature that was less than 660.4°C(the melting point of aluminum), a portion of quartz was happened decomposition and revivification to silicon, most aluminum still existed in the form of metal aluminum. All quartz were happened at the temperature that was higher than 660.4°C. When the temperature is 700°C, the compressive strength of S5(added 40% quartz) is up to 46.02MP. The higher the value of compressive strength was, the less the amount of quartz were happened decomposition. At the temperature more than the melting point of aluminum, Quartz was revivification to silicon, aluminum is oxidized to Al2O3. When the amount of silica exceeded 10%, the mechanical properties of composites declined consequently.

The total bauxite reserves of China are about 3.7 billion tons, however the principal and the first-class bauxite reserves account for only about 20%. A large number of coal gangue was accumulated on the surface of earth, which not only encroaches land but also pollutes the environment. In this study, low-grade bauxite with alumina content of 53.18 wt.% originating from Shanxi Yangquan and coal gangue with alumina content of 38.07 wt.% originating from Shanxi Datong were used to synthesize mullite materials. Bauxite and gangue were mixed by the ratio of 1 to 1. The ingredients were prepared according to the alumina content of 45.63 wt.% and 70 wt.%, by adding a certain amount of industrial alumina, respectively. The samples were sintered at 1350°C to 1600°C after being milled, dried and formed. The influence of alumina content and sintering temperature on the phase, microscopic morphology and properties of samples were discussed. The results show that, the main phases of the sample with the alumina content of 70 wt.% were mullite (more than 60 %) and corundum after being sintered for 4h at 1600 °C. The phenomenon of columnar mullite and granular corundum staggering had been observed. The bulk density and the bending strength of sample is 3.21 g/cm3and of 220.73 MPa respectively.

This paper mainly discusses the influences of heating temperatures and CeO2additive contents on the phase transformations of zirconia from zircon ore by carbothermal reduction. The phase transformations of zirconia from zircon ore by carbothermal reduction were monitored by X-ray diffraction. The microstructure of the product was characterized by scanning electron microscopy. The results show that without adding CeO2, the optimized heating temperature of zircon carbothermal reduction was 1600 °C and the main phases of the product were m-ZrO2, ZrC and β-SiC, t-ZrO2; After adding CeO2, the main phase of the products consists of t-ZrO2, m-ZrO2, ZrC and β-SiC when the heating temperature is 1600 °C. CeO2additive can be introduced into zirconia lattice and can cause it to form cerium stabilized zirconia. Zirconia in the product would be turned into partially stabilized zirconia with cerium addition from 5 wt% to 20 wt%. However, the form of zirconia in the product is not changed greatly with the amount of CeO2additive increase.

In this paper, the KNN powders with Li+ substituted (K0.5Na0.5)+ were prepared by the sol-gel method in order to make powders pure, (Na0.50+xK0.50-2xLix) -NbO3 (x=0, 0.04, 0.06, 0.08) ceramics were prepared by pressureless sintering. The phase composition of powders was determined by XRD. The effects of the Li+ substitution on piezoelectric and ferroelectric properties of ceramics were systematically studied for determining optimal Li+ content. Li+ can significantly increase the piezoelectric constant of ceramic. When Li+ content was 0.04, piezoelectric properties of ceramics were the best, d33=115 pC/N, Pr=6.35 μC/cm2, Ec=14.24 kV/cm.

In this study the phase behavior of diatomite during magnesiothermic reduction process was investigated. Two packing routes were adopted to estimate the reduction effectiveness at a low reaction temperature of 650 °C for 2h. The phase and microstructure evolution of diatomite were investigated by XRD, SEM, EDS. The results show that diatomite was sucessessfully reduced by the magnesium vapor and reaction products were Si, MgO, and Mg2Si when the raw diatomite was blended with Mg powder. Mg2Si and MgO were alternatively and incompletely dissolved after being immersed in a 1 M HCl solution for 6 h. Meanwhile, the reactant molar ratio had an important influence on products when the raw diatomite was separated with the Mg powder. A small amount of diatomite was reacted to generate MgO and Mg2Si as the molar ratio of Mg and diatomite was 2:1. By contrast, with the molar ratio increasing to be 10:1, diatomite was completely reacted to be Mg2Si and MgO.

Objective To explore the relationship between the arterial oxygen saturation (SaO2) as a susceptibility risk factor for acute mountain sickness (AMS) in healthy people entering a high altitude area abruptly. Methods A search in Medline, PubMed, Springer, Elsevier and LWW databases was done to collect the reports concerning SaO2 as a susceptibility risk factor for AMS from 2000 to 2010 published in literature abroad, and meta-analysis was performed with RevMan 5.0 software. Results Nine papers concerning the relationship of AMS and SaO2 were retrieved. The heterogeneity test indicated that the nine studies were consistent statistically (Q=12.98, df=10, P>0.05), the data from these nine studies could be analyzed by fixed effect model. After combination of the data, those of 246 subjects with AMS and 557 subjects without AMS were collected. Test of overall effect by fixed effect model showed that the SaO2 was significantly lower in AMS group than in non-AMS group (weighted mean difference was 4.04, 95%CI was 3.36-4.71, P

The non-sintering Ti (C,N)-Si3N4-SiC composite refractories were prepared using natural quartz, rutile and silicon carbide particles/powders as the raw materials, phenolic resin and urotropin as a complex binder and silicon powder as the additive. The influence of the binder amount on the density, flexural strength, volume shrinkage and the microstructure of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories was studied in detail. The results showed that the amount of binder has significant effects on the properties of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories. The bulk density decreased and the apparent porosity increased as the amount of binder increased, and the flexural strength increased and then decreased as the amount of binder increased, and the volume shrinkage increased with the increase of the amount of binder. The binder is propitious to the properties of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories, but excessive binder will result in the degradation of properties of the as-fabricated composite refractories, the optimum amount of complex adhesive is 15%.

In the log interpretation, the CBM content evaluation methods include: regression, LAN’s equation, KIM method, neural network, and so on. This paper investigates the suitability of these methods for a CBM reservoir in Southern Qinshui Basin, Shanxi Province of China, and finds out the most reasonable interpretation model of CBM content in this area. The results show that the composite parameter(COMP) method and the LAN’s equation method are more suitable for evaluating the CBM content in this study area, while the other methods are not.

In the present work, a novel compound purifying tank was adopted in the rural sanitary sewage treatment. The cultivation and acclimation of biological film could be completed in a short start-up by aerobic precoating. According to the running results,the average COD removal rate reached 59.62%,and the removal efficiency of TP was 33.4%.For the denitrogenation,the removal rates were not remarkable (21.7 to NH4+-N,21.9 to TN),but the large removal quantity of NH4+-N and TN were abtained as 8.58mg/L and 9.12mg/L,respectively. The study suggests that the compound purifying tank is a potential alternative for rural sanitary sewage treatment.

The purpose of interactive design is to achieve good usability and user experience, that is to say a good interactive design not only to help users achieve the basic operation, but also in the interactive process allows users to have a positive emotional experience. Because the usability and user experience focus on the direction is not consistent. Definition and evaluation criteria are different, which in many cases, the interaction design is difficult to meet the consistency of the two. Thus, the theory of Embodied cognition theory in psychology can provide an opportunity to establish a unified usability and user experience. Based on the current cognitive psychology of new orientation of Embodied cognitive research progress, combined with the development trend of mobile payment in recent years. The relationship between usability, user experience, and Embodied cognition is analyzed experimentally by interacting with the payment form. The discovery of usability and user experience is based on the cognitive orientation of the implicit measurement method and the traditional assessment of the design method of continuous iterative design evaluation. According to the idea of cognitive design, combined with people-centered design ideas, proposed to build a process based on specific cognitive payment form interaction. The biggest characteristic of this process is to unite the evaluation criteria of usability and user experience for the purpose of cognitive design, which lays the foundation for the establishment of systematic and scientific cognitive mobile interactive design method. Finally, our practical experiment applies the theoretical method of mobile interactive design based on cognitive knowledge and proves the availability of the method.

Alumina from sericite phyllite was extracted by the way of limestone self-pulverization sintering technique. The key technical processes, including self-pulverization sintering, clinker leaching reaction and the carbonation decomposition, were investigated systematically. The results showed that the main phases of pulverized clinker consisted of γ-C2S and C12A7, and the self-pulverization rate was 95% . The dissolution rate of Al2O3 clinker could reach 86.7% when the concentration of Na2CO3 solution was 7% and the solid-liquid ratio was 1:3. The Al(OH)3 prepared at 80°C carbonation temperature and pH=10.5 was relatively pure, with hexagonal plate-like crystals. The α-alumina could be acquired by calcination at 1200°C with the content of 99.71% Al2O3 and 0.02% Na2O. This work provided optimal technological parameters for effectively extracting alumina from the sericite and other inexpensive non-bauxite mineral resources with A/S ratio lower than 1.

Glycogen synthase kinase-3β (GSK-3β) plays a key role in type II diabetes and Alzheimer's diseases, to which non-ATP competitive inhibitors represent an effectively therapeutical approach due to their good specificity. Herein, a series of small molecules benzothiazepinones (BTZs) as novel non-ATP competitive inhibitors of GSK-3β have been designed and synthesized. The in vitro evaluation performed by luminescent assay showed most BTZ derivatives have inhibitory effects in micromolar scale. Among them compounds 6l, 6t and 6v have the IC50 values of 25.0 μM, 27.8 μM and 23.0 μM, respectively. Moreover 6v is devoid of any inhibitory activity in the assays to other thirteen protein kinases. Besides, SAR is analyzed and a hypothetical enzymatic binding mode is proposed by molecular docking study, which would be useful for new candidates design.

In this paper, SiC nanowires were successfully synthesized on Si substrate by the thermal evaporation method without the assistance of a metal catalyst. The phase composition, morphology and microstructure of the SiC–SiO 2 core–shell nanowires were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The SiC nanowires produced grew along the [111] direction and had diameters of 50–100 nm with lengths of several hundreds of microns. The SiC nanowire was composed of a single-crystalline SiC core with a thin amorphous SiO 2 shell. The growth mechanism of the nanowires can be explained by the vapor–solid (VS) process.

Tourmaline has characteristics of repeatedly producing electric dipole polarity transformation. Using FTO glass substrate coated with conductive films as raw materials, the research aims to prepare functional glass materials, which have spontaneous polarization effect, absorption of wideband electromagnetic radiation and high visible light transmittance. This paper applied Magnetron Sputtering deposition technique, studying on tourmaline as target, sputtering on conductive FTO glass, using multiple means to measure and analyze the surface morphology, component, structure, electrical and magnetic properties. And the functions of tourmaline as composite electromagnetic shielding films are also discussed in the paper.

Ultralong single crystal Sialon nanobelts were prepared on a graphite cover coated with Ni(NO3)2 by facile thermal chemical vapor deposition reactions of Si, Al, and Al2O3 with flowing N2 at 1450 °C. The as-synthesized Sialon nanobelts were up to several millimeters long and several hundred nanometers wide, and they had width/thickness ratios of 5–15. Their growth process was codominated by a Ni-catalytic vapor–liquid–solid (VLS) base-growth mechanism and a vapor–solid (VS) tip-growth mechanism. The former was responsible for the initial nucleation and proto-nanobelt formation of Sialon and the subsequent growth along the [100] direction, and the latter additionally contributed the growth at tips. The room-temperature photoluminescence (PL) spectrum showed that the as-synthesized Sialon nanobelts had a special emission with two maximum peaks at 409 nm (3.03 eV) and 428 nm (2.90 eV) located in the violet-blue spectral range, making possible potential applications in LED and optoelectronic nanodevices.

Silicon nitride (β-Si3N4) nano-belts had been synthesized by used silica bricks and carbon powder as raw materials through carbothermal reduction nitridation. The morphology and microstructure of β-Si3N4 nano-belts were characterized by scanning electron microscopy (SEM/HRSEM), energy disperse spectrum (EDS) and X-ray diffraction (XRD). Results showed that the well-crystallized β-Si3N4 nano-beltes were grown with thinness of 50-150nm and width of 3-5μm. The relatively purer β-Si3N4 were prone to be thin films with thinness of 150nm, while the as-grown SiCN (impurityβ-Si3N4with C elements) were presented as nanorods with cross section length of 150*150nm. Orientation growth mechanism by grain dislocation and vapor-solid (VS) mechanism were both involved in the growth of nanostructures of β-Si3N4 nano-beltes and SiCN nanorods.

In this study, β-Sialon/Al2O3/TiN diphase powder was synthesized using low-grade bauxite and rutile via carbothermal reduction-nitridation. The phase transitions of low-grade bauxite and rutile in the carbothermal reduction and nitridation process were analyzed by XRD, SEM and EDS. The effects of different reaction parameters such as reaction temperature, rutile addition on the phase composition and microstructure of products were analyzed. The results showed that β-Sialon/Al2O3/TiN powder was prepared using low-grade bauxite and rutile as raw materials and coke as reducing agent by carbothermal reduction-nitridation reaction in flowing nitrogen atmosphere of 0.03 MPa at 1350-1375 °C, for 4 h.