Shandong University of Technology
Recent publications
Nucleic acids (DNA and RNA) play crucial roles in guiding protein synthesis and plant resistance to biotic and abiotic stresses, but our current available understanding concerning on the role and function of nucleic acid metabolism, transcription and translation processes in postharvest fruit and vegetables remains largely unclear. In this study, an iTRAQ-based proteomics was used to investigate changes of protein abundance in postharvest broccoli under 40% O2 + 5% CO2, 20% O2 + 5% CO2 and 5% O2 + 5% CO2 treatments. A total of 128 differentially expressed proteins (fold change ≥ 1.2) were identified. High O2 stress reduced the DNA level by down-regulating the expression of proteins involved in DNA replication and up-regulating the expression of proteins DNA degradation. The decrease of DNA content, inhibition of transcription and promotion of RNA degradation induced by high O2 stress further led to the mass loss of RNA content in postharvest broccoli. Additionally, high O2 stress suppressed RNA processing, transport and translation and activated the expression of 20 S and 26 S proteasome, thereby accelerating the decrease of protein levels in postharvest broccoli. The decrease of DNA and RNA content might be related to the early yellowing and senescence in postharvest broccoli. This study revealed that the effect and mechanism of high O2 stress on DNA and RNA metabolism, transcription and translation processes, and the role of these metabolic pathway on senescence in postharvest broccoli.
Background Despite accumulating epidemiological studies support that diabetes increases the risk of Alzheimer’s disease (AD), the causal associations between diabetes and AD remain inconclusive. The present study aimed to explore: i) whether diabetes is causally related to the increased risk of AD; ii) and if so, which diabetes-related physiological parameter is associated with AD; iii) why diabetes drugs can be used as candidates for the treatment of AD. Two-sample Mendelian randomization (2SMR) was employed to perform the analysis. Results Firstly, the 2SMR analysis provided a suggestive association between genetically predicted type 1 diabetes (T1D) and a slightly increased AD risk (OR = 1.04, 95% CI = [1.01, 1.06]), and type 2 diabetes (T2D) showed a much stronger association with AD risk (OR = 1.34, 95% CI = [1.05, 1.70]). Secondly, further 2SMR analysis revealed that diabetes-related physiological parameters like fasting blood glucose and total cholesterol levels might have a detrimental role in the development of AD. Thirdly, we obtained 74 antidiabetic drugs and identified SNPs to proxy the targets of antidiabetic drugs. 2SMR analysis indicated the expression of three target genes, ETFDH, GANC, and MGAM, were associated with the increased risk of AD, while CPE could be a protective factor for AD. Besides, further PPI network found that GANC interacted with MGAM, and further interacted with CD33, a strong genetic locus related to AD. Conclusions In conclusion, the present study provides evidence of a causal association between diabetes and increased risk of AD, and also useful genetic clues for drug development.
To improve the quality and efficiency of Z -directional 3D preform forming, the Z -yarn frictional force distribution model of the preform and its wear mechanism were investigated. In this study, a tensile force measuring device was designed to measure the force required to replace the guide sleeve, which is equivalent to the Z -yarn frictional forces. The frictional force is proportional to the number of preform layers and is applied to the preform decreased from the corner, edge, sub-edge, and middle in order. A back propagation neural network model was established to predict the friction at different positions of the preform with different layers, and the error was within 1.9%. The wear of Z -yarn was studied at different frictional positions and after different times of successive implantation into the preform. The results showed that with an increase in the number of Z -yarn implantations and frictional forces, the amount of carbon fiber bundle hairiness gradually increased, and the tensile fracture strength damage of the fiber was increasingly affected by the frictional forces. In the corner position of the preform, when the number of implantations was 25, the fiber fracture strength decreased non-linearly and substantially; in order to avoid fiber fracturing in the implantation process, the Z -yarn needs to be replaced in time after 20–25 cycles of continuous implantation. This study solves the problem of difficulty in measuring the force required for individual replacements owing to the excessive number of guide sleeves, puts forward the relationship between fiber wear, preform position, and implantation times, solves the phenomenon of fracture in the preform during Z -direction fiber implantation, and realizes the continuous implantation of fibers.
A compact stress measurement system for transparent objects was proposed based on the combination of photoelascity and DGS methods. The interferometry fringe and speckle image of the deformed specimen were captured from perpendicular and slant directions, respectively. The fundamentals of the stress calculation and imaging model of oblique camera viewing were analyzed mathematically. After phase-shifting computation, image correlation, and geometric transformation, full-field distributions of the major and minor intrinsic principal stresses were obtained simultaneously. A validation experiment was conducted on a circular disk under diametral compression by the proposed method. Comparison between the experimental resulsts and theoretical data calculated according to the theory of elasticity verified the feasibility and accuracy. Moreover, the combined method was also successfully applied for the intrinsic principal stresses determination on transparent wrinkling thin film with defects subjected to shearing forces.
The co-liquefaction of lignite and heavy residues is regarded as a promising technique for upgrading inferior feedstock, but is limited in the long-term by several engineering challenges that must be overcome before commercialization, in particular to the excessive catalyst consumption and production of solid residue (SR) waste. Herein, the SR waste was transformed into a favorable catalytic additive via a simple activation method that simultaneously decreased the required hydrogenation-catalyst dosage and enabled the resulting hazardous wastes to be utilized. The inorganic minerals contained within coal had a positive influence on the hydro-conversion of the co-liquefaction system and the dispersion of SRs, which motivated us to exploit the enriched minerals in SRs by further activation treatments. The application of activated SRs as cheap additives resulted in an enhanced catalytic performance in co-liquefaction reactions, with a sharp decrease in the required hydrogenation catalyst dosage of nearly 60%. The exposure of iron sulfides in activated SRs following the partial removal of organic carbonaceous matter and silica-alumina minerals provided additional catalytic activity for promoting hydrogenation reactions and aromatic-aliphatic bond cleavages. Furthermore, the modified pore structure of activated SRs with a sharply increased surface area was beneficial for restricting coke deposition on the surface of hydrogenation catalysts and reacted coals, and thus improved the catalytic environment of reaction systems with a relatively economic catalyst dosage.
Icing on transmission lines is a challenging problem in the world. Rime icing on silicone rubber insulator was taken as research object in this paper. The position coordinates of supercooled water droplets collided with the surface of the insulator were extracted, the local collision coefficient (E) of the droplet was calculated by a triangular area ratio method. The “point-line-face-solid” ice shape reconstruction algorithm was proposed to realize three-dimensional numerical simulation of rime ice accretion on the insulator. The results shown that the effect of median volume diameter (MVD) of the droplet on the E is greater than that of wind speed (v). The most serious icing occurs on the rod and the edge of the shed. Due to the shielding effect of the shed, the icing on the rod presents the shape of the nose. The length, thickness and amount of rime icing on the insulator calculated by the model increases with time, whose average errors with that obtained by the tests are 7.68%, 7.96%, 10.34%, and 9.45%, respectively. Moreover, the simulated icing distribution is well consistent with the experimental results. Therefore, the effectiveness of the numerical simulation method was proved in the present research.
Accurate estimation of the state-of-charge (SOC) is of extreme importance for the reliability and safety of lithium-ion battery operation, for prevention of overcharge, deep discharge, and irreversible damage to batteries. Traditional SOC estimation methods do not consider the effect of temperature on estimation, which may lead to significant errors in the SOC estimation. Considering the effect of temperature change on SOC estimation for lithium-ion batteries, this paper presents a SOC estimation method based on adaptive dual extended Kalman filter (ADEKF). First, the radial basis function neural network (RBFNN) and the forgetting factor recursive least square (FFRLS) methods are adopted to characterize the relationship between battery temperature and polarization resistance and capacitance (RC) of the dual-polarization model based on experimental lithium-ion battery data, then the relationship between identified RC parameters and temperature is described by the temperature characteristic function. Secondly, an estimation method based on the ADEKF is proposed to update the RC parameters online. This method could reduce the SOC estimation error caused by the mismatch between the set RC parameter value and the actual RC parameter value due to ambient temperature changes. Finally, the experimental data of federal urban driving schedule (FUDS) at -10°C, 25°C, and 50°C are selected to simulate and verify the SOC estimation method proposed in this paper. The results indicate that, compared with the method not considering the effect of ambient temperature, the method developed in this paper is able to achieve accurate SOC estimation with a smaller root mean square error and mean absolute error in a wide range of temperatures.
The frost-free air-source heat pump (ASHP) with integrated liquid desiccant dehumidification is a more promising energy-saving alternative to the conventional ASHP unit. The performance of spray-type finned-tube heat exchanger (FTHE), as one of the key equipment of this frost-free ASHP system, is affected by a combination of various factors including wall wettability, liquid film flow pattern, liquid film thickness, velocity distribution in a liquid film, interface wave, interface velocity and so on. To provide a theoretical basis for the operation, design and optimization of high-performance spray-type FTHE, a visualization experiment system and a three-dimensional (3D) numerical model are employed to study the behaviors of counter-current gas-liquid falling film flow on the air-side of two-row plain FTHE under different parameters in the present paper. According to the experimental results, the flow pattern of liquid film on the finned-tube surface is a mixture flow composed of the rivulet flow and the thin falling film flow, demonstrating that the assumption of the uniform distribution for liquid film thickness proposed in previous studies is not completely consistent with the actual situation. Meanwhile, the numerical results indicate that the transient-average film thickness on the surface of two-row plain finned-tube is significantly 18.3% – 32.5% higher than that on the vertical plate calculated by Nusselt's model. After that, the critical gas and liquid Reynolds numbers of the flow pattern transition for the liquid film are obtained, and it is pointed out that the wall contact angle of 10° is more conducive to the formation of complete film flow on the air-side of the two-row plain FTHE within the fin pitch range of 4.8 – 6.0 mm. The changes of the falling liquid film and gas-liquid interface characteristics are fundamentally attributed to the drag effect of the interfacial shear force. Furthermore, there is a cubic curve relationship between average interface shear force and gas Reg. A quadratic curve relation exists between average wall shear stress and gas Reg. At the same time, the velocity of falling film fluid at the bottom region of laminar flow is reduced, resulting from the inhibiting effect of the interfacial shear force.
Based on ferrocene (Fc)-labeled primers and graphdiyne-methylene blue (GDY-MB) nanocomposite, a ratiometric electrochemical aptasensor was prepared for high-precision detection of kanamycin (KAN). The Fc-labeled primer hybridized with the aptamer forms a rigid structure. When KAN was specifically bound to an aptamer, a primer with a self-complementary sequence was released to form a hairpin structure (HP), drawing the Fc close to the electrode surface, resulting in enhanced IFc. Exonuclease I (Exo I) was used to cleave the single-stranded aptamer and release the target, effectively increasing the cyclic amplification signal. The phosphorylation was carried out at the 3′ end of the primers to prevent HP cleavage. The chitosan - antimony tin oxide (CS-ATO) and AuNPs were used to further modified the electrodes to double the signal amplification. Under the optimal experimental conditions, the KAN concentration exhibited a strong linear relationship with IFc/IMB. The R² (0.997) of the calibration curve was greater than the R² (0.960) of the standard curve of KAN concentration and IFc, which indicates the robustness of the ratiometric electrochemical sensor. The limit of detection (LOD) was 6.044 nM. The aptasensor exhibits strong stability and specificity for successfully detection of KAN in real milk samples.
Coal remains an irreplaceable main energy source in China. This paper uses the zero-sum gain data envelopment analysis (ZSG-DEA) model, and proposes a production capacity optimization allocation plan, which provides a theoretical basis for how to ensure energy security in the context of China's dual-carbon strategy. Results show: (1) the optimal plan adjusts the production capacity by 7.32 million tons/year, accounting for 6.33% of the total production capacity; 32 mines will be increased in production capacity, and 19 mines will be reduced in production capacity. (2) Under the optimal plan, the raw coal output, income, and profit of provincial coal mines will increase by 3.5965 million tons, 2.65 billion yuan, and 0.972 billion yuan, respectively, and wages are expected to decrease by 73.5 million yuan. (3) In terms of the fairness of personnel placement, the Gini coefficient of the actual situation is 0.3082, and that of the optimal scheme is 0.2896. It suggests that engaging in the “one size fits all” campaign of marginalization and coal decoalization is unadvisable. Coal supply and market demand should be efficiently connected, and the elimination of backward production capacity and the release of advantageous production capacity should be rationally coordinated.
This paper reports a form-stable molten salt based composite phase change material (CPCM) owning extremely low melting point and large temperature range that can be a promising candidate used in low and middle temperature thermal energy storage fields. The composite was prepared by a so-called cold compress and hot sintering approach with a eutectic quaternary nitrate of Ca(NO3)2-KNO3-NaNO 3-NaNO 2 used as phase change material (PCM), a MgO as structure supporting material (SSM) and graphite as thermal conductivity enhancer (TCE). A series of characterizations were carried out to investigate the composite microstructure, chemical compatibility and thermal properties as well as cycling stability. The results show no chemical reaction occurred among the compositions of salt, SSM and TCEM before and after sintering, indicating excellent chemical and physical compatibility in the composite. A fairly low melting point around 89.56 °C and relatively high decomposition temperature of 628 °C were observed, giving the composite a large energy storage density over 626 kJ/kg at temperature range of 50–600 °C. A mass loading of 50% MgO gives the optimal formulation of the composite at which over 10% graphite can be involved and a thermal conductivity over 1.4 W/m⋅ ∘C can be obtained. The present results indicate that such a salt based composite with fairly low melting temperature and large temperature range could be an effective alternative to organic based PCMs used in low-mid temperature thermal energy storage.
Technological progress has a positive footprint on the global economy, and this can curb carbon emissions. This study aims to estimates the technical progress and CO2 emissions from Bangladesh’s manufacturing and industrial sector covering the period 1980 to 2018. We carried a quantile regression model to analyze the impact of technological progress on CO2 emissions and to establish the association among the variables. The study’s empirical outcomes are: First, the model’s R-square reaches 0.9, which suggests that these models clarify the driving factor of carbon emissions more than 90%. Second, the manufacturing sectors’ technological progress has a positive impact while the industrial sectors’ technological progress has mix impact on CO2 emissions. Third, the estimated CO2 emissions growth is rising with lower environmental effects from 2019 to 2040. Fourth, the estimations and policies might help Bangladesh contribute to improving management capability, technical development, public awareness, energy-saving technologies, energy efficiency measures, and supporting green technology in both sectors. Further policies are given below, which will assist Bangladesh’s policymakers in acknowledging appropriately.
To increase the transient power limit, and reduce the impact of operating condition changes on the electric vehicles’ powerful battery, it is essential to stabilize the working condition, enhance the vehicle’s dynamic performance and energy utilization. In this paper, a novel mechanical–electro–hydraulic power coupling system for electric vehicles is proposed. It integrates a planetary gear mechanism as a power coupling component with an accumulator, a hydraulic pump/motor, which efficiently converts electrical, mechanical, and hydraulic energy. A rule-based dynamic energy management strategy is established to control the energy distribution and the dynamic switching of working conditions in real time. By analyzing the system’s operating mode, a new vehicle model is established. First, the feasibility and superiority of the new model are verified compared with the pure electric vehicle model. Simultaneously, the vehicle speed jitter problem during electro–hydraulic power switching is eliminated by altering the inclination angle of the secondary element. Ultimately, the verification results illustrate that the battery power consumption is reduced by 14.7%, and the energy recovery rate of the accumulator is as high as 94.3%. Furthermore, reasonable distribution of the torque in two motors through fuzzy control strategy significantly stabilizes the main motor’s working state and improves its overall efficiency.
Let Fq be the finite field of q elements and let D2n=〈x,y|xn=1,y2=1,yxy=xn−1〉 be the dihedral group of 2n elements. Left ideals of the group algebra Fq[D2n] are known as left dihedral codes over Fq of length 2n, and abbreviated as left D2n-codes. Let gcd(n,q)=1. In this paper, we give an explicit representation for the Euclidean hull of every left D2n-code over Fq. On this basis, we determine all distinct Euclidean LCD codes and Euclidean self-orthogonal codes which are left D2n-codes over Fq. In particular, we provide an explicit representation and a precise enumeration for these two subclasses of left D2n-codes and self-dual left D2n-codes, respectively. Moreover, we give a direct and simple method for determining the encoder (generator matrix) of any left D2n-code over Fq, and present several numerical examples to illustrative our applications.
Many experiments simulate the corona phenomenon on the surface of single grounding wire of transmission line in an ideal environment, without considering the influence of environmental factors such as wind. In this paper, the finite element method is used to consider the motion process of small positive ions, large aerosol ions and aerosol neutral particles. Based on the simulation results, the shielding effect between two grounding wires can be seen by comparison. Considering the wind speed from 0 m/s to 5 m/s, the grounding wire corona discharge experiment was carried out. The simulation and experimental results show that with the increase of wind speed, the corona discharge degree on the surface of the grounding wire increases, the positive ion concentration generated by the corona increases, and the corona current increases. The positive ion offset increases, the shielding effect on the grounding wire weakens, and the electric field intensity above the grounding wire increases, which increases the probability of the corona to flow beam transition. With the increase of wind direction angle, the positive ion density on the grounding wire surface increases, which weakens the spatial electric field intensity and is not conducive to the development of upward leader.
Postharvest fruit decay is one of the most important limitations for the fruit industry, which results in tremendous economic losses. Methyl jasmonate (MeJA), a critical hormone that participates in postharvest fruit disease control, could activate the autophagy pathway in plants, which plays an important role in stress response. To reveal the role of autophagy in MeJA-induced postharvest fruit resistance against Botrytis cinerea, green-mature tomato fruit was treated with 0.05 mmol L⁻¹ MeJA for 12 h after immersing 50 mmol L⁻¹ lithium chloride (LiCl, an activator of autophagy) or 5 mmol L⁻¹ hydroxychloroquine (HCQ, an inhibitor of autophagy), respectively, for 10 min and stored at 25 ± 1 °C for 12 d The results indicated that MeJA treatment induced transcript levels of autophagy-related genes (SlATGs), promoted autophagosome formation, as well as inhibited disease incidence and lesion diameter of postharvest tomato by activating the transcript levels of genes related jasmonic acid (JA) signaling pathway (SlLOX, SlAOC, SlMYC2, and SlCOI1) and regulating reactive oxygen species (ROS) metabolism, including the increased activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase and the decreased contents of superoxide anion radical and hydrogen peroxide. However, the above impacts regulated by MeJA were weakened by HCQ pretreatment and boosted by LiCl pretreatment. Moreover, correlation analysis suggested that disease development was negatively correlated with the transcript levels of genes related to autophagy and JA signaling pathway, especially SlATG13a, SlATG18a, and SlMYC2. The principal component analysis also showed that autophagy was involved in MeJA-induced postharvest fruit quality regulation. Overall, these findings indicated that MeJA treatment enhanced postharvest fruit disease resistance, at least in part, via the JA and autophagy pathway.
In this paper, the weighted L1-gain analysis and control synthesis for switched positive linear systems are investigated via a weighted edge-dependent average dwell time approach. First, a novel multiple convex copositive Lyapunov function is devised in a polytopic form with clock-dependent function coefficients, which not merely upgrades the degrees of freedom of the Lyapunov function considerably, but also permits the descent at switching instants. By weighted edge-dependent switching technique, the feasible switching zone is greatly extended, and the dwell time constraint is eliminated for each subsystem. In a particular scenario, the lower bound on the weighted sum of all dwell times can be even erased thoroughly, and the relevant non-weighted L1-gain results can be derived. Furthermore, two L1-gain convex control laws are derived in time-varying forms, comprising state feedback and output feedback, which can be updated continuously during the running time of systems. Finally, a positive circuit system and two numerical examples are presented to conduct comparative studies with other clock-dependent Lyapunov function results, suggesting that the proposed results perform better under low complexity on L1-gain, switching zone, computation time, etc, and improve transient performances such as settling time and overshoot.
In nature, the hydroxyl radical (•OH) is produced during the anaerobic-aerobic transition when groundwater level fluctuates. In addition, the •OH is also detected in iron-bearing clay minerals and iron oxides during the redox process. Goethite is one of the most stable iron oxides involved in biogeochemical cycles. In this study, the coexisting humic acid (HA) enhanced the generation of Fe(II) during the iron reduction process and accelerated the generation of •OH in the redox process of goethite. The organic contaminants in black and odorous water were decomposed by constructing an iron-reducing bacteria-HA-Fe(II)/Fe(III) reaction system under anaerobic-aerobic alternation. The results demonstrated that in the anaerobic stage, HA could promote the reduction and dissolution of goethite through the complexation effect and electron shuttle mechanism, as well as significantly strengthening the iron reduction process in water. Under aerobic conditions, Fe(II) in the reaction system would activate O2 to generate •O2⁻. The •OH, formed by Fe (II) and •O2⁻ via Fenton reaction and Haber-Weiss mechanism, oxidized dissolved organic matter (DOM) in water. The characterization of DOM by three-dimensional fluorescence spectroscopy (3DEEM) indicated that after four redox fluctuations, the organic contaminants in water samples were effectively degraded. Generally, this study provides new approaches and insights into the biogeochemical cycling of Fe and C elements and water pollution remediation at the anoxic-anoxic interface.
Biomass transformation into fuels, platform chemicals and materials contributes to developing sustainability and carbon neutralization. Pyrolysis is one of the most important approaches to valorize biomass. The distributed activation energy model (DAEM) is a comprehensive kinetic model for describing biomass pyrolysis kinetics. The estimation of the DAEM parameters is difficult because of the complex structure of the DAEM equation. This work formulated the numerical calculation approach of the DAEM and proposed a hybrid simulated annealing (SA) algorithm and pattern search (PS) method for optimizing the DAEM parameters. The DAEM kinetic parameters were evaluated by simultaneously fitting the experimental kinetic data of cellulose, xylan and lignin pyrolysis at various heating rates with the DAEM using the proposed hybrid optimization method. The results showed that the proposed hybrid optimization method could effectively and accurately determine the DAEM parameters and the DAEM with the optimal parameters could reproduce the experimental kinetic data of xylan, cellulose and lignin pyrolysis very well. The distributed activation energies of xylan, cellulose and lignin predicted by hybrid optimization were centered at 162.8, 222.8 and 236.7 kJ mol⁻¹, respectively, with standard deviations of 4.6, 0.8 and 25.9 kJ mol⁻¹, respectively. The reaction orders of xylan, cellulose and lignin pyrolysis are 1.7, 1.1, and 2.5, respectively.
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710 members
Chengfeng Li
  • School of Materials science and Engineering
Jianfeng Wang
  • School of Mathematics and Statistics
Hongbo Zhao
  • School of Civil and Architectural Engineering