Search

Fe2O3-C-Ni heterojunction structured composite on foam Ni was successfully prepared by simple and effective hydrothermal reaction. The obtained material had good structural stability and excellent electrical conductivity. This binder-free Fe2O3-C-Ni electrode exhibits typical pseudocapacitance. Specific capacitance of Fe2O3-C-Ni in 1.0 mol L-1 KOH reaches 844.6 F g-1, which is higher than that of Fe2O3-Ni and C-Ni electrodes. For practice application, assembled Fe2O3-C-Ni//AC capacitor exhibits a long-term cycling performance with remains 79.5% capacitance retention within 20000 cycles at 1 A g-1.

Metal oxide electrode materials have relatively high theoretical capacitance. However, structure, morphology and composition of this kind of materials have significant influence on electrochemical performance. Moreover, metal oxide electrode materials have problems of low power density and cyclic stability. In this work, Mo-doped hydroxide zinc carbonate material (Mo-HZC) is synthesized on foam Ni surface by hydrothermal method. This Mo-doping electrode exhibits typical pseudocapacitance. Specific capacitance of Mo-HZC in 1.0 mol L-1 KOH is 698.9 F g-1 (1.0 A g-1), which is 2.5 times that of the undoped sample. The maximum energy density and power density of Mo-HZC electrode are 32.1 WH kg-1 and 3.16 KW kg-1, respectively. Assembled Mo-HZC//AC capacitor exhibits a long-term cycling performance with remains 79.5% capacitance retention within 20 000 cycles at 1.0 A g-1.

Purpose: To compare the diagnostic accuracy of plasma aldosterone concentration (PAC), plasma renin activity (PRA) and aldosterone-to-renin ratio (ARR) in primary aldosteronism (PA) using radioimmunoassay (RIA) and chemiluminescence immunoassay (CLIA) methods. Methods: Both RIA and CLIA were used to analyze the PAC, PRA and ARR with subjects in standing or supine position, before and after a saline infusion test (SIT). The correlation between RIA and CLIA was measured by regression analysis. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy by RIA and CLIA. Results: A positive correlation was found between PAC and PRA after SIT using RIA and CLIA (0.1745 and 0.3085, respectively). A positive correlation was found between the PAC and PRA in standing and supine position using RIA and CLIA (0.3979 vs 0.2399 and 0.1885 vs 0.4032, respectively). There was no obvious difference in AUCs of PAC, PRA, and ARR between RIA and CLIA (PAC: 0.91 vs. 0.89; PRA: 0.88 vs. 0.87; ARR: 0.93 vs. 0.92). In standing posture, the AUCs of PAC, PRA and ARR using RIA were 0.63, 0.72 and 0.78, respectively, and the results of CLIA were 0.65, 0.75 and 0.82, respectively. In supine posture, the AUC of PAC, PRA and ARR using RIA was 0.65, 0.68 and 0.71, respectively, and the results of CLIA were 0.68, 0.70 and 0.79, respectively. Conclusion: Chemiluminescent assay is reliable for diagnosis of PA when compared with radioimmunoassay.

Tuberculosis (TB) is one of the world’s deadliest infectious disease killers today, and despite China’s increasing efforts to prevent and control TB, the TB epidemic is still very serious. In the context of the COVID-19 pandemic, if reliable forecasts of TB epidemic trends can be made, they can help policymakers with early warning and contribute to the prevention and control of TB. In this study, we collected monthly reports of pulmonary tuberculosis (PTB) in Guiyang, China, from January 1, 2010 to December 31, 2020, and monthly meteorological data for the same period, and used LASSO regression to screen four meteorological factors that had an influence on the monthly reports of PTB in Guiyang, including sunshine hours, relative humidity, average atmospheric pressure, and annual highest temperature, of which relative humidity (6-month lag) and average atmospheric pressure (7-month lag) have a lagging effect with the number of TB reports in Guiyang. Based on these data, we constructed ARIMA, Holt-Winters (additive and multiplicative), ARIMAX (with meteorological factors), LSTM, and multivariable LSTM (with meteorological factors). We found that the addition of meteorological factors significantly improved the performance of the time series prediction model, which, after comprehensive consideration, included the ARIMAX (1,1,1) (0,1,2)12 model with a lag of 7 months at the average atmospheric pressure, outperforms the other models in terms of both fit ( RMSE = 37.570 , MAPE = 10.164 % , MAE = 28.511 ) and forecast sensitivity ( RMSE = 20.724 , MAPE = 6.901 % , MAE = 17.306 ), so the ARIMAX (1,1,1) (0,1,2)12 model with a lag of 7 months can be used as a predictor tool for predicting the number of monthly reports of PTB in Guiyang, China.

The separation of andalusite and quartz was investigated in the sodium oleate flotation system, and its mechanism was studied by solution chemical calculation, zeta-potential tests, Fourier transform infrared spectroscopic (FTIR), and X-ray photoelectron spectroscopic (XPS). The flotation tests results show that FeCl3·6H2O has a strong activation effect on andalusite and quartz and citric acid has a strong inhibitory effect on activated quartz, thus increasing the floatability difference between quartz and andalusite when the pulp pH is approximately 8. The FTIR, Zeta potential, and XPS analyses combined with the chemical calculation of flotation reagent solutions demonstrate that Fe forms hydroxide precipitates on the surface of andalusite and quartz and that oleate anions and metal ions adsorb onto the surface of the minerals. The elements Al and Fe can be chemically reacted. The anions in citric acid have different degrees of dissolution of Fe on the andalusite and quartz surfaces, thereby selectively eliminating the activation of the elemental Fe on andalusite and quartz and increasing the floatability of andalusite, leading to a better separation effect between andalusite and quartz.

Ferric ions produced during grinding influence the flotation separation between kyanite and quartz adversely. In this study, citric acid was used as a regulator to eliminate the effect of ferric ions on the separation of kyanite from quartz with sodium oleate (NaOL) as a collector. The microflotation test results indicated that the quartz was selectively activated by FeCl3 and maintained significant quartz recovery. However, the citric acid could selectively eliminate the effect of ferric ions on the quartz and minimally influenced the kyanite. Contact angle tests demonstrated that FeCl3 significantly increased the interaction between NaOL and quartz, resulting in the high hydrophobicity of quartz, and the addition of citric acid made the quartz surface hydrophilic again but slightly influenced the kyanite. Fourier-transform infrared spectroscopy showed that FeCl3 facilitated NaOL adsorption onto the quartz surface, and the addition of citric acid eliminated the activation of FeCl3 on the quartz, resulting in the nonadsorption of NaOL onto the quartz surface. However, the FeCl3 and citric acid exhibited a negligible effect on NaOL adsorption onto the kyanite surface. X-ray photoelectron spectroscopy analysis indicated that the citric acid eliminated FeCl3 activation on the quartz.

A numerical simulation method is hereby adopted in this paper to calculate and analyze the thermal dispersion influence factors of three particle-shaped porous mediums of two-dimensional porous medium with different skeleton structures. Result shows that the thermal dispersion influence factors include fluid thermal properties, Darcy velocity, porosity and skeleton structure, etc. Under the same condition, the thermal dispersion coefficient of a circular particle model is maximum, and it increases with the rise of Pednumber; with the increase of the porosity or the reduction of Darcy velocity, the thermal dispersion coefficient reduces increasingly. When considering the thermal dispersion effect, the axial temperature variation of fluid is more applicable for numerical simulation, which proves that it shall consider the thermal dispersion during researches on porous medium models.

Mobile e-commerce systems are the big trend of international economy and social development now days, and also the key process of industry upgrade, industrialization and modernization in our country. Mobile e-commerce systems are considered as the backbone of the manufacturing industry in China, Vulnerabilities in web applications continue to be the most frequently discovered security problem. This article illustrates a trusted operating systems how to provide a flexible solution to the problem of application for e-commerce. With the help of Chinese Wall, web services are becoming popular in Web applications. In the end, we present strategies for e-commerce application: trusted e-commerce module.

Dynamic response performance of PEMFC affects its durability and reliability significantly. So improving on dynamic performance of PEMFC has become the key for prolonging PEMFC life in fuel cell vehicles application. In this study, in order to promote the PEMFC dynamic response performance, RuO2·xH2O was prepared by solgel method and then sprayed onto catalyst layers. The RuO2·xH2O prepared was characterized by TEM, which shows the average particle size of RuO2·xH2O was 8 nm and particulates were well distributed. A 10-cell stack using MEAs with and without RuO2·xH2O was assembled and studied under different relative humidity. It was found that added with RuO2·xH2O dramatically improves the dynamic response performance, which revealing that RuO2·xH2O can buffer the voltage undershoot and improve the stability and lifetime of PEMFC stack.

Fe3O4 modified Pt/C electro-catalyst was synthesized and studied. Fe3O4 and Fe3O4 with carbon coating (designated as Fe3O4/C) were prepared by co-precipitation method and ethyl acetate pretreatment. Fe3O4 and Fe3O4/C were sprayed onto the Pt/C cathode surface. X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) results show that Fe3O4 and Fe3O4 with carbon coating nano-particles (Fe3O4/C) are distributed evenly and c.a. 11.2 nm and 14.3 nm, respectively. TEM images show that electrode surfaces with Fe3O4 and Fe3O4/C are of little difference from that with Pt/C only; Fe3O4/C is much more evenly distributed on the electrode surface than Fe3O4 because of the adaptability of carbon coating. Cathodic curves of Rotating Disk Electrode (RDE) tests shows that the adding of Fe3O4 (7 wt %) improves oxygen reduction reaction (ORR) activity about 30 mV in both cases. The adding of Fe3O4/C (Fe3O4: 7 wt %) to the Pt/C catalysts demonstrates the highest peak current of about 13.8 mA•cm-2 in all cases. The promotion of Fe3O4 in O2 enrichment and dispersion of Pt particles are confirmed in the study. The paramagnetism of Fe3O4 and its promotion in 4-electron oxygen reduction reaction (ORR) are the possible reasons for the promotion.his template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Coal samples in the air for three months were characterized by Thermogravimetric Analysis (TGA). The effect of a PVA oxygen-insulating barrier on the spontaneous combustion of coal was examined. The moisture loss activation energy, oxidation activation energy and combustion activation energy were calculated by an integral method using the Coats-Redfen formula. The results show that the tendency for spontaneous combustion of three coal samples (judged by the activation energy) falls in the order: CYW>YJL>SW. The oxidation activation energy and combustion activation energy of coal protected by the PVA oxygen-insulating barrier increased. A significant increase in the combustion activation energy was noted, especially for the CYW coal where the increase was 28.53 kJ/mol. Hence, oxidation of the protected coal samples was more difficult. The PVA oxygen-insulating barrier helps to prevent spontaneous combustion of the coal.

An effective method for preventing spontaneous combustion of coal stockpiles on the ground is to control the air-flow in loose coal. In order to determine and predict accurately oxygen concentrations and temperatures within coal stockpiles, it is vital to obtain information of self-heating conditions and tendencies of spontaneous coal combustion. For laboratory conditions, we designed our own experimental equipment composed of a control-heating system, a coal column and an oxygen concentration and temperature monitoring system, for simulation of spontaneous combustion of block coal (13–25 mm) covered with fine coal (0–3 mm). A BP artificial neural network (ANN) with 150 training samples was gradually established over the course of our experiment. Heating time, relative position of measuring points, the ratio of fine coal thickness, artificial density, voidage and activation energy were selected as input variables and oxygen concentration and temperature of coal column as output variables. Then our trained network was applied to predict the trend on the untried experimental data. The results show that the oxygen concentration in the coal column could be reduced below the minimum still able to induce spontaneous combustion of coal — 6% by covering the coal pile with fine coal, which would meet the requirement to prevent spontaneous combustion of coal stockpiles. Based on the prediction of this ANN, the average errors of oxygen concentration and temperature were respectively 0.5% and 7 °C, which meet actual tolerances. The implementation of the method would provide a practical guide in understanding the course of self-heating and spontaneous combustion of coal stockpiles.

Cold chain logistics is a complex system, involving the whole process of temperature control of the entire chain from the packaging, transporting, storage and consumption of the products. The meeting of the market demand must be based on the forecasting. The main goal of this study is to forecast product demand values for cold chain logistics from 2010 to 2015 in China using GM (1,1). The residents’ consumption data of refrigerated and frozen food ranging from meat to milk were obtained from the China statistical yearbook of 2005 to 2009. A gray forecast equation of cold chain logistics demand is established and estimated by DPS 7.05 software so as to confirm its scientific and accurate forecasting system. The results show all the prediction accuracy of GM (1,1) model of the refrigerated and frozen food demand of historical data reached level 1 except average residual error, which reached level 2. So, we can see that the previous established GM (1,1) models have achieved good prediction effect. Meanwhile, by 2015, the amounts of products transported under refrigeration condition will be more than 55,649 tons, with a 4.3 proportion growth per year in the period of 2010 to 2015. Key words: Cold chain logistics, demand forecasting, grey model, China.

Digital works are considered as research focus in most existing digital copyright protection schemes. But the customers not the digital works have active aggressiveness. That is to say the customers are the fundamental reason of copyright protection problem. So customers should be monitored moreover. The existing identity authentication could verify the legitimacy of customers. But it can not distinguish the legitimacy of customer operations. In this paper, we propose an effective behavior authentication scheme for customers based on fragile watermark and multiple robust zero watermark technology. After using a digital work, the scheme can decide whether the digital work is used beyond the usage authority and determine the customer who exceeded authority further. It is known that the scheme could be applied in most situations by validity analysis. The experiment results also show that the scheme is executed efficiently and correctly.

A novel tamper-proof model of Web pages using virus-based watermarking is proposed in this paper. The model provides a good security and accuracy about judging the situation of Web page tampering. The classifying theory based on virus is applied when watermark embedded and extracted. The proposed scheme is applied in all kinds of HTML or XML files, not just for English letters but also for the rest of characters. More importantly, it can be restored to the original file completely when the watermark is extracted. Therefore, the proposed scheme, associated with 3rd generation technology of tamper-proof for web pages, exhibits a good property of real-time performance and security. Experiment results show that it overwhelms existing schemes of tamper-proof in that it does not increase the file size and it does not expend great computing time such as cryptography.

Micro RNAs are small, non-coding RNA molecules that regulate gene expression via either translational inhibition or mRNA degredation. Enhancer of zeste homolog 2 (EZH2)-mediated hypertrophic signaling is a major regulatory response to hypertrophic stimuli. In this study, we constructed AAC rat models and PE-induced hypertrophic cardiomyocytes. We demonstrated that miR-214 relative levels were upregulated, whereas EZH2 was downregulated in both vivo and vitro models. Further, one conserved base-pairing site in the EZH2 3′-untranslated region (UTR) was verified. Mutation of the site in the EZH2 3′-UTR completely blocked the negative effect of miR-214 on EZH2, suggesting that EZH2 is a direct target for miR-214 regulation. Using a gain-of-function approach, incorporating the lentivirus constructed miR-214 and its sponge, we demonstrated that miR-214 significantly regulated endogenous levels of EZH2 gene expression; whereas, changes in the expression of the Sine oculis homeobox homolog gene were induced by an adrenergic receptor agonist in the AAC rat model. Having made this study it is possible to conclude that the negative regulation of EZH2 expression contributed to miR-214-mediated cardiac hypertrophy.