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As a metal-free photocatalyst, graphitic carbon nitride (g-CN) shows great potential for photocatalytic water splitting, although its performance is significantly limited by structural defects due to incomplete polymerization. In the present work, we successfully synthesize highly conjugated g-CN nanofoam through an iodide substitution technique. The product possesses a high polymerization degree, low defect density, and large specific surface area; as a result, it achieves a hydrogen evolution rate of 9.06 mmol h

When increasing steam parameters, the incomplete thermodynamic cycle and large irreversible system losses are bottlenecks in improving thermal efficiency in ultra-supercritical power plants. In this study, a comprehensive analysis of both parameter optimization and system cycle analysis is carried out for a 1000-MW double reheat ultra-supercritical thermal power plant. First, the genetic algorithm is used to optimize the primary and double thermal pressure, as well as the steam extraction parameters of the steam turbine. Then, a thermodynamic optimization model is proposed to analyze performance. Moreover, the exergy analysis method is applied to reveal the irreversibility mechanism in the thermodynamic cycle. In order to further solve the energy-grade mismatch problem, the performance of a regenerative steam turbine thermal system is improved based on the optimized system. The results indicate that the power generation efficiency of the optimized system is 0.31% higher than that of the prototype system, and the heat consumption rate is decreased by 43.67 kJ (kW h)−1. The power generation efficiency in the regenerative steam turbine system is up to 52.42%, which is 1.44% higher than that of the optimized system. Therefore, an effective method to improve the thermal efficiency is obtained through the thermodynamic cycle analysis and optimization for 700 °C ultra-supercritical double reheats systems.

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

Abundant information resides in the pressure signal of a fluidized bed, especially when the pressure signal of that bed is mixed with steady flow, and the pulsed flow is more prevalent. In this paper, the authors established a stable and pulsed flow fluidized bed experiment platform. They also collected pressure signals with different times, different frequencies and different gas flow rates in the drying process. The pressure signals were analyzed by two approaches. One is based on the use of the multi-scale complexity entropy causality plane, and the other relies on a recurrence plot. With the drying characteristics of wet particles in the bed and flow pattern, the focus was on influence factors such as time lapse, air intake ratio and pulse frequency on both drying efficiency and the characteristics of complex nonlinear dynamics were analyzed. A study of the micro and macro mechanism of flow characteristics is also presented. The results show that the two approaches (i.e., methods) have a higher accuracy in judging the change of the interaction force between moist particles and the change of flow characteristics. The drying efficiency can be deduced by analysis of the dynamic characteristics of the fluidized bed; thus, the multi-scale complexity entropy causality plane and the structure of the recurrence plot corresponding to the best drying efficiency are obtained. A recommended reference range of the three parameters of a recurrence plot that are good for drying will be presented, which corresponds to the ratio of the stable flow and the pulsed flow.

Anaerobic digestion is a feasible method for vinegar residue disposal. However, its treatment efficiency is limited significantly by the low degradation of lignocellulose. In this study, a stable and efficient anaerobic digestion system for vinegar residue was constructed. The continuous solid-state reactor achieved a specific production of 418 mL·g-1 VS biogas and 223 mL·g-1 VS methane at a high organic loading rate (OLR) of 5.83 gVS·(L·d)−1. The stable degradation of lignocellulose between 39.5% and 36.4% was key factor for stable anaerobic digestion at high OLR. This stability under optimum OLR was due to the increase in the degradation of hemicellulose, which compensated for the loss of lignocellulose degradation. The enrichment of microorganism related to lignocellulose hydrolysis and the stable microbial community structure ensured efficient anaerobic digestion under high OLR condition. Digestion efficiency can be further improved mainly by increasing cellulose degradation. This investigation provided the theoretical basis for practical application of this digestion system for solid vinegar residue treatment.

In gas and liquid two-phase flow, different flow patterns show their unique nonlinear dynamic characteristics due to the complex interaction between them. To further reveal the underlying dynamic characteristics of this physical phenomenon, this paper presents a new model for the analysis of small channel gas-liquid two-phase flow pattern signals based on the multi-scale normalized Benford probability distribution (MSNBPD) analysis. The first focus area is the difference between the characteristics of a multi-scale approach to Benford’s probability distribution and Benford’s Law (BL) distribution in a typical nonlinear system. Once the terms are defined, the authors show how BL could be applied in a multi-scale based flow-pattern based method to analyze differential pressure signals of gas-liquid two-phase flow in small channels to reveal the underlying dynamic characteristics of different gas-liquid two-phase flow patterns, and their sensitivity to scale changes. In addition, the stability of different flow patterns was revealed by the variable scale range calculation. Flow patterns could then be distinguished based on Euclidean distance and the variable scale range difference of differential pressure signals. This paper also compares the present method with other methods that have been used in flow identification. The results show that this new method can well distinguish nonlinear systems with different dynamic mechanisms. This method can also reveal the underlying dynamic characteristics of a gas-liquid two-phase flow of micro and small channels. The two characteristic values (Euclidean distance and variable scale range difference) proved to be a good distinction for two-phase flow patterns than other time and frequency methods, with several possible universal applications. However, the identification results of micro and small channels were better than that of regular pipe, which shows that this method is more suitable for the identification of micro and small channel flow.

With the increasing requirement of high computational power in computational fluid dynamics (CFD) field, the graphic processing units (GPUs) with great floating-point computing capability play more important roles. This work explores the porting of an Euler solver from central processing units (CPUs) to three different CPU/GPU heterogeneous hardware platforms using MUSCL and NND schemes, and then the computational acceleration of one-dimensional (1D) Riemann problem and two-dimensional (2D) flow past a forward-facing step is investigated. Based on hardware structures, memory models and programming methods, the working manner of heterogeneous systems was firstly introduced in this paper. Subsequently, three different heterogeneous methods employed in the current study were presented in detail, while porting all parts of the solver loop to GPU possessed the best performance among them. Several optimization strategies suitable for the solver were adopted to achieve substantial execution speedups, while using shared memory on GPU was relatively rarely reported in CFD literature. Finally, the simulation of 1D Riemann verified the reliability of the modified codes on GPU, demonstrating strong ability in capturing discontinuities of both schemes. The two cases with their 1D computational domains discretized into 10,000 cells both realized a speedup exceeding 25, compared to that executed on a single-core CPU. In simulation of the 2D step flow, we came to the highest speedups of 260 for MUSCL scheme with 800 × 400 mesh size and 144 for NND scheme with 400 × 200 computational domain, respectively.

One of the most important controlled parameters of thermal power units is the boiler drum water level. Disturbances of feed water flow rate could cause instability of the drum water level. This study proposes the Gray correlation compensation (GCC) control technology for the Boiler feed water pump turbine (BFPT) to solve this problem. Simulation results indicate that the GCC controller outperforms the traditional proportional-integral-derivative controller when it encounters different disturbances. Furthermore, the GCC controller can rapidly switch to the high-pressure steam source to ensure that the drum water level is in the secure range during steam source switching of the BFPT.

The Co-Ni mixed oxides/graphene composite has been prepared using the solution based oxidation route. The structures of bare Co-Ni mixed oxides and Co-Ni mixed oxides/graphene composite is clearly studied by X-ray diffraction. The electrochemical properties of Co-Ni mixed oxides/graphene composite are investigated by Cyclic Voltammetry (CV) and galvanostatic charge discharge test. The result shows that, the NiO phase has not been detected in the composite, and the graphene composite delivers a discharge capacity of 353.6 F/g at a current density of 0.32 A g-1.

Recently, blackouts have occurred frequently due to various reasons. When the fault in the power grid is repaired, fast cut back (FCB) technology can restore power quickly. Therefore, it is necessary to establish a dynamic mathematical model of thermal power plant to simulate FCB. In this paper, a dynamic mathematical model of 300 MW thermal power plant was built up, which was based on the principles of mass and energy balance. The model considered feed water heater systems, bypass system, and feed water pumps. The heat absorption characteristics of steam-water systems during FCB were considered as well. This model has been verified by the FCB field tests under the conditions of 50% and 100% economize continue rate (ECR) load.

In this paper, a facile hydrothermal synthesis of precursor MnO2 and subsequent high-temperature calcination has been used to prepare sea-urchin-like Mn2O3.The influences of calcination temperatures on the structures and electrochemical performances of Mn2O3 are clearly studied. The results show that the elevated temperature helps to improve the crystallinity and particle size, the 700°C sample shows an optimal electrochemical performance. Therein, a high discharge capacity of 765.7 mAh g− 1 can be retained after 50 cycles at 200 mA g− 1, and a value of 465.8 mAh g− 1 can be kept at 800 mA g− 1.More importantly, a surprised calcination temperature determines phenomenon that discharges capacity increase upon cycles can be observed, which may be useful for the design and nanostructured of Mn-based oxides as lithium-ion battery anodes.

The blend cathode materials LiMn2O4/Li1.2(Mn0.56Ni0.16Co0.08)O2 have been successfully prepared by the physical mixing of commercial Li2MnO4 and self-prepared Li1.2(Mn0.56Ni0.16Co0.08)O2 nanoparticles. The structures, morphologies and electrochemical performances are characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Cyclic Voltammetry (CV) and charge-discharge test, and the results show that the good mass ratio of Li2MnO4 and Li1.2(Mn0.56Ni0.16Co0.08)O2 is 50:50. Therein, the nanosized Li1.2Ni0.16Co0.08Mn0.56O2 uniformly adhere on the surface of Li2MnO4 micro structure, and occupy the gap of Li2MnO4 particles, which can effectively elevate the tap density of Li1.2(Mn0.56Ni0.16Co0.08)O2 nanoparticles. As lithium ion battery cathode, the 50:50 sample reveals an initial discharge capacity of 265.4 mAh/g with negligible irreversible capacity loss at current density of 0.1C within 2.0-4.8 V, and retain 89.2% after 20 cycles.

The model of high solid anaerobic digestion was used by improving the degree of homogeneity of the reaction system and biogas slurry reflux to gradually increase the material load. The vinegar residue-efficient anaerobic digestion system was successfully constructed without pretreatment.The optimum anaerobic digestibility was observed when the material loading of the reaction system reached 6.15 g·(L·d)

Nano-ZnO/bamboo charcoal composites were prepared by precipitation with bamboo charcoal as support. Nano-ZnO/bamboo charcoal composites were characterized by XRD, SEM and EDS. Photocatalytic degradation processes of methyl orange were studied. The results indicate that the structure of nano-ZnO is of the wurtzite type and the grain size is about 19-54 nm. The best preparation temperature for these composites is 500℃. The composites have better photocatalytic degradation ability than pure ZnO under UV irradiation. Photocatalytic degradation of methyl orange with the composites obeys first-order kinetics, and the composites can be recycled.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17397

The main purpose of this paper is the analysis of the influence of steel fiber and hybrid fiber on the ultimate shear load and failure mode of rectangular concrete beams. The results of this experiment study indicate that fibers can enhance the ultimate shear load. Hybrid fibers can change the failure mode. The mechanical behavior of beam with hybrid fibers is better than that with mono-steel fibers.

This paper presents a new model pertaining to the change rule of critical heat flux (CHF) in parallel mini-channels under the action of an electric field force. The working fluid in this experiment is R141b. The mass flow rate of the working fluid is 36-44 kg m−2 s−1, and the heating power of the heating plate is 50-180w. A new CHF prediction formula is based on the experimental results. To make this new prediction method more applicable and accurate, a new dimensionless electric field, referred to as force “E”, is proposed, which can characterize the magnitude of the electric field force. The experimental results show that the electric field force can affect wall temperature and the pressure difference between the inlet and outlet, as well as the heat transfer coefficient and CHF of the channel. By comparing the experimental data with the predicted value, the prediction accuracy of the CHF is within ±15% based on the new prediction model.

At the different elevation of the spouted bed riser pipe layout pressure measuring point, each point below is equipped with purge air, avoid the granular poly group on the pressure measuring point, by adjusting the frequency of the bandpass filter, guarantee the accuracy of pressure measurement. Through experimental study, under the low superficial air velocity, riser pipe pressure pulsation standard deviation has a linear relationship with the superficial air velocity and obey the chi-square distribution, based on the above found , rising pipe pressure pulsation standard deviation forecast the incidence of granular poly group is proposed in this paper. By comparing rising pipe pressure pulsation standard deviation forecast method with conventional average pressure drop forecast method found, rising pipe pressure pulsation standard deviation has higher superficial air velocity recognition rate and less response time when the granular poly group,achieves the spouted bed fast forecast the granular poly group phenomenon.

This paper is based on the wavelet transform theory and the Hilbert transform, it aims at researching on the pressure fluctuation characteristics in the bed, through analyzing and comparing the calculated envelope spectrum of pressure signal after transforms. On the basis of self-built cold fluidized bed, we choose to change the air flow and diameter of particle in fluidized bed as the two influencing factors. For researching the pressure fluctuation characteristics of fluidized bed, we collect pressure signal of the large particle fluidized bed which under normal operation conditions. The experimental results reveal that: as the increasing of the air flow, the energy of pressure increases; and with the increase of particle size in fluidized bed, the pressure fluctuation decreases in the bed.

Gambogic acid (GA) is the major active ingredient of gamboge, which is secreted from a Chinese traditional medicine, Garcinia hanburyi, which possesses potent antitumor activity. GA3, a new GA derivative, has been shown to possess better water solubility than GA. The aim of the present study was to examine the antitumor activity of GA3 and the mechanism underlying it.The growth inhibition of cancer cell lines induced by GA3 was assessed using the SRB assay. DAPI staining, flow cytometry, a DNA fragment assay, and Western blot analysis were used to study the apoptotic mechanisms of GA3.GA3 displayed wide cytotoxicity in diversified human cancer cell lines with a mean IC(50) value of 2.15 micromol/L. GA3 was also effective against multidrug resistant cells, with an average resistance factor (RF) that was much lower than that of the reference drug, doxorubicin. Mechanistic studies revealed that GA3-induced apoptosis in HL-60 cells proceeded via both extrinsic and intrinsic pathways, with caspase-8 functioning upstream of caspase-9. In addition, GA3-driven apoptotic events were associated with up-regulation of Bax, down-regulation of Bcl-2 and cleavage of Bid. Moreover, GA3 triggered cytochrome c release from the mitochondria, in particular bypassing the involvement of the mitochondrial membrane potential.Better solubility and a potential anti-MDR activity, combined with a comparable antitumor efficacy, make GA3 a potential drug candidate in cancer therapy that deserves further investigation.

Gambogic acid (GA) is the major active ingredient of gamboge secreted from a Chinese traditional medicine Garcinia hanburryi possessing potent anti-tumor activity. N-(2-ethoxyethyl)gambogamide (NG-18), a derivative of GA, also efficiently inhibits proliferation of cultured human tumor cells. The inhibition effect of NG-18 is associated with its ability to induce apoptosis. In the present study, NG-18 markedly induced leukemia HL-60 cells apoptosis, and the extrinsic and intrinsic apoptosis pathways were activated almost at the same time. NG-18-induced tumor cell apoptosis was associated with up-regulation of pro-apoptotic Bcl-2 family member Bax, and downregulation of anti-apoptotic protein Bcl-2. The NG-18-induced apoptosis was blocked completely by a pan-caspase inhibitor Z-VAD-FMK, indicating that caspases were functionally and actively involved in this process. The specific inhibition of caspase-8 activity using Z-IETD-FMK significantly blocked NG-18-induced apoptosis. In contrast, inhibition of other initiator caspases, caspase-2 or -9, using Z-VDVAD-FMK or Z-LEHD-FMK respectively had no effect on NG-18-induced apoptosis. Altogether, our data demonstrated that NG-18-induced apoptosis was dependent on caspases and caspase-8 acted as a key executor in the event.

The tranditional thermal calculation program cannot satisfactorily reflect the variety steam temperature characteristics of boiler burning mixture of pulverized coal and blast furnace gas(BFG). In order to resolve this problem, the method of combining experimental study and thermal calculation is adopted. The program is checked with a lot of experimental data. The heat transfer coefficient of every main heated surface is corrected. The thermal calculation program is assured and it will become a more dependable basis for the boiler design, operation optimization and reconstruction.

During biped robot moving, it is hard to avoid external impulse. If biped robot receives external impulse, its joint velocity has abrupt changes. As a result, biped robot deviates from normal status, to quickly reject external impulse, impulse model of biped robot is conducted, and compensation acceleration to each joint is calculated. Changes of joint angle and joint angle velocity are eliminated. Finally the rejecting method is proved effective by simulation result of biped robot.