363 research outputs found
Dynamic Evolutionary Game Analysis of Symbiosis System in E-commerce Industrial Park
Based on the evolutionary game theory and the bounded rational and asymmetric information assumptions, we construct the dynamic evolutionary game model between the three game players and analyze the replication dynamic equations. Furthermore, we analyze the strategy of three symbiosis units and the evolution mechanism of E-commerce industrial park symbiosis system. Finally, two conclusions are drawn: Conclusion 1, the probability that three symbiosis units of E-commerce Industrial Park choosing the symbiosis strategy increases with increase of the probability that the other two symbiosis units selecting the symbiosis strategy. Conclusion 2, the probability of the symbiosis unit to choose the symbiosis strategy increase with the increase of the benefit and decrease with the increase of the cost, risk and loss
Identification of a male-specific amplified fragment length polymorphism (AFLP) marker in Broussonetia papyrifera
The present study exhibits amplified fragment length polymorphism (AFLP) molecular marker for sex identification in Broussonetia papyrifera. Based on nine selective amplification primer combinations, 230 bands were produced and the E-AGG/M-CAA combination was found to be a male-specific AFLP marker. Subsequently, this male-specific AFLP fragment was sequenced and converted into a sequence tagged site (STS) marker. Based on STS sequence, two primers, MADB-1 and MADB-2 (Male-Associated DNA from B. papyrifera), were designed to verify the specificity of the fragment. The results indicate that common homology sequence is existed in both male and female plants while one of the bands amplified via MADB-2 primer was solely present in male individuals at high annealing temperature up to 66°C. Finally, MADB-2 primer was introduced to amplify another 16 plants and it revealed that this primer could be used as a convenient, efficient, reliable, and low-cost molecular marker for sex identification in B. papyrifera.Keywords: Broussonetia papyrifera, AFLP, STS, male-specific marke
On the positive effect of UVC light during the removal of benzothiazoles by photoelectro-Fenton with UVA light
Benzothiazole (BTH) and 2-hydroxybenzothiazole (2-OH-BTH) are ubiquitous pollutants in aquatic ecosystems. This article reports their photoelectro-Fenton (PEF) treatment, either alone or mixed, in sulfate medium at pH 3.0 using an IrO2-based/air diffusion cell that generates H2O2 under UVA and/or UVC irradiation. UVC-PEF was more effective than UVA-PEF to remove the target pollutants, which suggests a positive impact of OH formed via Fenton's reaction and photo-induced homolysis of H2O2 in the former method. In addition, BTH disappeared more quickly than 2-OH BTH. Full-time UVA-/UVC-PEF outperformed UVC-PEF and UVA-PEF to mineralize the mixtures, although requiring a much higher energy consumption. The evolution of generated H2O2 and homogeneous OH confirmed the positive contribution of UVC photolysis in UVA-PEF. Part-time use of UVC radiation in UVA-PEF yielded a similar total organic carbon removal, with much lower energy consumption. BTH was oxidized to 2-OH-BTH, which was subsequently transformed into other five heteroaromatics
Tailoring Intermolecular Interactions Towards High‐Performance Thermoelectric Ionogels at Low Humidity
Development of ionic thermoelectric (iTE) materials is of immense interest for efficient heat-to-electricity conversion due to their giant ionic Seebeck coefficient (Si), but challenges remain in terms of relatively small Si at low humidity, poor stretchability, and ambiguous interaction mechanism in ionogels. Herein, a novel ionogel is reported consisting of polyethylene oxide (PEO), polyethylene oxide-polypropylene oxide-polyethylene oxide (P123), and 1-ethyl-3-methylimidazolium acetate (Emim:OAC). By delicately designing the interactions between ions and polymers, the migration of anions is restricted due to their strong binding with the hydroxyl groups of polymers, while the transport of cations is facilitated through segmental motions due to the increased amorphous regions, thereby leading to enlarged diffusion difference between the cations and anions. Moreover, the plasticizing effect of P123 and Emim:OAC can increase the elongation at break. As a consequence, the ionogel exhibits excellent properties including high Si (18 mV K−1 at relative humidity of 60%), good ionic conductivity (1.1 mS cm−1), superior stretchability (787%), and high stability (over 80% retention after 600 h). These findings show a promising strategy to obtain multifunctional iTE materials by engineering the intermolecular interactions and demonstrate the great potential of ionogels for harvesting low-grade heat in human-comfortable humidity environments
Fabrication and Thermoelectric Properties of Graphene/ Bi
Graphene/Bi2Te3 thermoelectric materials were prepared by spark plasma sintering (SPS) using hydrothermal synthesis of the powders as starting materials. The X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) were used to investigate the phase composition and microstructure of the as-prepared materials. Electrical resistivity, Seebeck coefficient, and thermal conductivity measurement were applied to analyze the thermoelectric properties. The effect of graphene on the performance of the thermoelectric materials was studied. The results showed that the maximum dimensionless figure of merit of the graphene/Bi2Te3 composite with 0.2 vol.% graphene was obtained at testing temperature 475 K, 31% higher than the pure Bi2Te3
Numerical simulation for optimizing the nozzle of moist-mix shotcrete based on orthogonal test
The nozzles of moist-mix shotcrete are the key parts of forming a steady jet flow field and ensuring the uniform mixing of water and other ingredients. In this paper, for optimizing the nozzle of moist-mix shotcrete, both the internal and external field of a variety of spray nozzles were simulated and analyzed by adopting orthogonal test method with Fluent simulation software combined. Then the phase volume fraction and single-phase velocity of the outlet section of flow field inside the nozzles and cloud pictures including single-phase velocity and volume of different sections lengthways in the external flow field of nozzle were obtained. The results demonstrated that the change of different factors and different levels of the same factor affected the shotcreting performance of spray nozzle, but the effect degree is different. Additionally, compared with the traditional nozzle, the rationality of new-type nozzle structure was verified, which provided a basis for the improvement and optimization of the nozzle structure in the future
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Synergistic effects of neck circumference and metabolic risk factors on insulin resistance: the Cardiometabolic Risk in Chinese (CRC) study
Objectives: Recent studies have associated neck circumference (NC) with insulin resistance (IR). We examined whether such relation was modified by other metabolic risk factors. Methods: The study samples were from a community-based health examination survey in central China. A total of 2588 apparently healthy Chinese men and women were included. Results: Plasma levels of total cholesterol (TC), HDL-C, uric acid (UA) and diastolic blood pressure (DBP) were independently associated with NC after adjusted for age, sex, body mass index (BMI), waist circumference (WC) and hip circumference (HC) (P = 0.009, 0.001, 0.015 and 0.015, respectively). We observed significant interactions of NC with triglyceride (TG) and UA (all the p for interaction = 0.001) in relation to HOMA-IR. It appeared that the associations between NC and HOMA-IR were more evident in those with higher UA or TG level. Conclusions: Our data indicate that in apparently healthy Chinese adults, there were synergistic effects of UA, TG and neck circumference on insulin resistance
Empirical prediction of blast-induced vibration on adjacent tunnels
The blast-induced vibration during excavation by the drilling and blasting method has an important impact on the surrounding buildings/structures and auxiliary equipment. In particular, with the development of tunnel engineering, the impact of blasting vibration on tunnel construction has attracted extensive attention. Based on literature data statistics, this paper first explored the performance of several commonly used empirical equations in predicting the propagation and attenuation characteristics of blasting vibration on adjacent tunnels. Secondly, the relationships between the empirical parameters of the blasting vibration prediction equation and the geological strength index (GSI) of tunnel surrounding rock were discussed, and two new blasting vibration prediction equations based on site rock GSI were established to approximately predict blast-induced vibration on adjacent tunnels. Finally, the application feasibility of the established prediction equation in practical engineering was discussed based on field test data. The research results show that under the condition of multiple groups of data, the prediction performance of various prediction models does not differ significantly. With the increase of the GSI of the surrounding rock mass of the adjacent tunnel, the site coefficients β and k of the blasting vibration prediction equation in predicting PPV (peak particle velocity, resultant velocity) both show a decreasing trend as a whole. The site coefficient k is generally within 3,000. Two new empirical prediction equations of blasting vibration propagation and attenuation on adjacent tunnels under different site conditions were established: Eq. (14) for PPV and Eq. (15) for PPVi (max) (maximum value of the three component velocities; i = x, y, z represent peak component particle velocity). The verification analysis of five sites shows that these two equations have a certain practical application value. Compared with other empirical equations, these two equations do not need regression fitting blasting vibration data, they only used the GSI of the site rock mass, and they are more easy to use in the field when there is a lack of monitoring data
Microstructure Characterization and Mechanical Properties of TiSi 2 -SiC-Ti 3 SiC 2 Composites Prepared by Spark Plasma Sintering
Dense TiSi 2 -SiC and TiSi 2 -SiC-Ti 3 SiC 2 composites in which SiC particles in 200-300 nm disperse, were reactively synthesized through spark plasma sintering (SPS) technique using TiC, Si, and C powders in micrometer as starting reactants. The phase constituents and microstructures of the samples were analyzed by X-ray diffraction, field emission scanning electron microscopy and transmission emission microscopy. The hardness, fracture toughness and bending strength of TiSi 2 -SiC and TiSi 2 -SiC-Ti 3 SiC 2 composites were tested at room temperature. The fracture toughness and bending strength of TiSi 2 -SiC-Ti 3 SiC 2 composites reach 5:4 AE 0:3 MPaÁm 1=2 and 700 AE 50 MPa, respectively. The factors leading to the improvement of the mechanical properties were discussed
High-level expression and purification of soluble recombinant FGF21 protein by SUMO fusion in Escherichia coli
<p>Abstract</p> <p>Background</p> <p>Fibroblast growth factor 21 (FGF21) is a promising drug candidate to combat metabolic diseases. However, high-level expression and purification of recombinant FGF21 (rFGF21) in <it>Escherichia coli (E. coli) </it>is difficult because rFGF21 forms inclusion bodies in the bacteria making it difficult to purify and obtain high concentrations of bioactive rFGF21. To overcome this problem, we fused the <it>FGF21 </it>with <it>SUMO </it>(Small ubiquitin-related modifier) by polymerase chain reaction (PCR), and expressed the fused gene in <it>E. coli </it>BL21(DE3).</p> <p>Results</p> <p>By inducing with IPTG, SUMO-FGF21 was expressed at a high level. Its concentration reached 30% of total protein, and exceeded 95% of all soluble proteins. The fused protein was purified by DEAE sepharose FF and Ni-NTA affinity chromatography. Once cleaved by the SUMO protease, the purity of rFGF21 by high performance liquid chromatography (HPLC) was shown to be higher than 96% with low endotoxin level (<1.0 EU/ml). The results of <it>in vivo </it>animal experiments showed that rFGF21 produced by using this method, could decrease the concentration of plasma glucose in diabetic rats by streptozotocin (STZ) injection.</p> <p>Conclusions</p> <p>This study demonstrated that SUMO, when fused with FGF21, was able to promote its soluble expression of the latter in <it>E. coli</it>, making it more convenient to purify rFGF21 than previously. This may be a better method to produce rFGF21 for pharmaceutical research and development.</p
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