Water scarcity and pollution have become a global problem, especially in China. Whether China can solve the water resources dilemma is closely related to its ability to achieve high-quality ...development. At present, studies on China’s water resources policy are relatively few and all of them are theoretical interpretations or regional studies. There is little literature examining the impact of China’s water resources policy on enterprises and its mechanisms. Therefore, this paper takes China’s water resource tax reform in 2017 as a quasi-natural event and constructs a difference-in-differences model to investigate the micro-governance effects of water resource tax reform based on panel data of high water-consuming enterprises listed in Shanghai and Shenzhen A-shares between 2012 and 2020. The findings of the study are as follows. Firstly, the water resource tax reform significantly improves the environmental performance of water-intensive enterprises. Secondly, through the mechanism test the author finds that water resource tax reform can promote the research and development of green invention patents in companies, which in turn improves their environmental performance. However, water resource tax showed no significant effect on green utility model patents. Finally, taking into account heterogeneity, this paper points out that the impact of the reform is more prominent in water-scarce regions and among large-scale enterprises. This paper provides experience and evidence for the promotion of water resource tax reform and inspires the author to give some policy recommendations. In the future, China should continue to implement water resource tax policy and increase technical and financial support to enterprises for green innovation.
Uncontrolled hemorrhage is closely related to the high risk of death. However, local hemostats still have various defects and side effects. Herein, an aldehyde dextran (PDA) sponge with proper ...absorption and adhesion properties is developed for hemorrhage control. PDA sponge with pore size of ∼30–50 μm fabricated by lyophilization not only absorbs blood quickly (47.7 g/g), but also possesses strong tissue adhesion (∼100 kPa). PDA sponge with low cytotoxicity and hemolysis achieves effective hemostasis and remarkable blood loss reduction in the ear vein, femoral artery and liver injuries of rabbit models. Furthermore, the exploration of hemostatic mechanisms related to tissue, blood, plasma, cells and coagulation system indicates that PDA sponge can significantly accelerate coagulation by rapid wound block, fast cells aggregation and initiation, and high coagulation factors concentration, instead of by the coagulation cascade activation. Importantly, this hemostat exhibits excellent biodegradability and nearly no skin irritation. Overall, the biodegradable and tissue adhesive PDA sponge will be a promising quick-hemostatic dressing for uncontrollable hemorrhage.
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Drastic changes in the random load of an electromechanical system bring about a reliability problem for the proportional solenoid valve based on a thermal effect. In order to accurately and ...effectively express the thermal load of a proportional solenoid valve under random load conditions and to meet the requirements of online acquisition, adaptive anomaly detection, and the missing substitution of thermal load data, a thermal load prediction model based on the Kalman filter algorithm is proposed. Taking the compound operation process of an excavator as the object and based on the field testing of an excavator and the independent testing experiment of a proportional solenoid valve in a non-installed state, a method of obtaining historical samples of the proportional solenoid valve's power and thermal load is given. The k-means clustering algorithm is used to cluster the historical samples of the power and thermal load corresponding to the working posture of a multi-tool excavator. The Grubbs criterion is used to eliminate the outliers in the clustering samples, and unbiased estimation is performed on the clustering samples to obtain the prediction model. The results show that the cross-validation of the sample data under the specific sample characteristics of the thermal load model was carried out. Compared with other methods, the prediction accuracy of the thermal load model based on the Kalman filter is higher, the adaptability is strong, and the maximum prediction deviation percentage is stable within 5%. This study has value as a reference for random cycle thermal load analyses of low-frequency electromechanical products.
The large fluctuations in charging loads of electric vehicles (EVs) make short-term forecasting challenging. In order to improve the short-term load forecasting performance of EV charging load, a ...corresponding model-based multi-channel convolutional neural network and temporal convolutional network (MCCNN-TCN) are proposed. The multi-channel convolutional neural network (MCCNN) can extract the fluctuation characteristics of EV charging load at various time scales, while the temporal convolutional network (TCN) can build a time-series dependence between the fluctuation characteristics and the forecasted load. In addition, an additional BP network maps the selected meteorological and date features into a high-dimensional feature vector, which is spliced with the output of the TCN. According to experimental results employing urban charging station load data from a city in northern China, the proposed model is more accurate than artificial neural network (ANN), long short-term memory (LSTM), convolutional neural networks and long short-term memory (CNN-LSTM), and TCN models. The MCCNN-TCN model outperforms the ANN, LSTM, CNN-LSTM, and TCN by 14.09%, 25.13%, 27.32%, and 4.48%, respectively, in terms of the mean absolute percentage error.
This study reports the application of polyglutamate acid (PGA) and amino-functionalised carbon nanotube (MWCNT-NH2) nanocomposite modified glassy carbon electrodes for the electrochemical ...determination of bisphenol A (BPA). The PGA/MWCNT-NH2 nanocomposite exhibits excellent electrocatalytic activity for the oxidation of BPA by substantially enhancing the current response and decreasing the BPA oxidation overpotential. The composite modified glass carbon electrode (GCE) exhibited good performance for detecting BPA due to the enhanced electron transfer kinetics and large active surface area. The effective enrichment of BPA is due to the carboxyl and amino groups on the composite. Under the optimised conditions and according to the results from differential pulse voltammetry (DPV), the BPA oxidation current is linear in a concentration range of 0.1 to 10μM (R=0.998), and the detection limit was determined to be 0.02μM (S/N=3). The proposed sensors were successfully employed to determine BPA in real plastic products, and the recoveries were between 95% and 108%. This strategy might enable more opportunities for the electrochemical determination of BPA in practical applications.
Magnesium alloys are promising materials for biodegradable vascular stents because of their good biocompatibility and physical properties. The poly-β-hydroxybutyrate (PHB) coating with vascular ...endothelial growth factor and heparin was prepared on the surface of WE magnesium alloys by layer-by-layer self-assembly technique. In this study, the effects of magnesium alloys with bioactive drug coating on human umbilical vein endothelial cells (HUVECs) and blood compatibility were investigated. The results showed that magnesium alloys with bioactive drug coating could decrease platelet adhesion, platelet activation, hemolysis rate, fibrinogen adsorption and increase activated partial thromboplastin time, prothrombin time, dynamic clotting of magnesium alloys. In addition, magnesium alloys with bioactive drug coating did not alter cytoskeleton morphological features of HUVECs, promoted cell adhesion and cell growth, and inhibited cell apoptosis. Therefore, the magnesium alloys with bioactive drug coating can be considered as potential and degradable biomaterials for vascular stents.
Objective To systematically evaluate the effect of physical exercise intervention on the activities of daily living (ADL) on patients with Alzheimer’s dementia (AD) and explore the optimal exercise ...scheme. Methods PubMed, EMBASE, the Cochrane Library, Web of Science, and Science Direct databases were searched from 1987 to December 2023 to collect randomized controlled trials (RCTs). Two investigators independently screened the literature and extracted data according to the inclusion and exclusion criteria. The quality of the included studies was evaluated using Cochrane Review Manager 5.3. And STATA 16.0 was used for performing the meta-analysis. Results Fifteen randomized controlled trials were included. The results of the meta-analysis showed that physical exercise had a positive effect on the improvement of ADL in patients with AD standardized mean difference (SMD) = 0.312, 95% confidence interval (CI 0.039–0.585), P = 0.02, and the difference was statistically significant. The results of subgroup analysis showed that anaerobic exercises such as strength and balance training with a medium cycle of 12–16 weeks and lasting 30–45 min each time were more ideal for the improvement of basic daily living ability of AD patients. Conclusion Physical exercise can effectively improve activities of daily living in patients with Alzheimer’s dementia and it may be a potential non-drug treatment for AD patients.
Increasing research effort has been made aiming at developing electromagnetic (EM) wave absorbing materials with high absorption performance. An ideal EM absorber should be relatively light-weight, ...thermally stable, capable of absorbing wide EM frequency, and cost effective. As a dielectric material, silicon carbide (SiC) has great potential with relatively low density, good thermal and chemical resistance, and it can function at high temperatures or under harsh working environments. This review summarizes the research progress in the design and characterization of SiC and SiC based composites as EM absorption materials. Pristine SiC with various morphological, phase, and structural features can be tailored to achieve better absorption performance. Moreover, SiC based materials can either be modified using dielectric or magnetic materials, or be designed with variation in geometry, composition, and mass fraction of the filler composition for further improvement in EM absorption. This review intends to inspire new concepts and approaches for designing excellent EM absorbing materials.
A review of research progress in the design and characterization of SiC based composites as electromagnetic wave absorbing materials.
To fight the global epidemic of drug-resistant bacteria, essential oils have gained increasing attention as a new source of antibiotics. The antimicrobial activity of Monarda didyma essential oils ...(MDEO) for the Carbapenem-resistant Klebsiella pneumoniae (CRKP) strains were determined by agar disc diffusion assay and broth microdilution assay. To further understand MDEO efficacy, a time-growth curve was performed. The biofilm formation of CRKP were determined by crystalline violet staining method, additionally, changes in intracellular Adenosine triphosphate (ATP), protein, Alkaline phosphatase (AKP) activities, and membrane integrity were investigated to assess the influence of MDEO on cell membrane damage. Finally, the activities of key enzymes in the tricarboxylic acid (TCA) pathways and pentose phosphate (PPP) pathways were examined to determine the effect of MDEO on the respiratory metabolism of CRKP. This study presents the antibacterial mechanism of MDEO against CRKP with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 1.25 mg/ml. To understand MDEO efficacy, a time-kill kinetics approach was performed. The bactericidal effect of MDEO was evident at 2 h compared to the control at its MIC and 2MIC. Surface electron microscopic and ATP assay studies provided evidence for the multi-target action of MDEO against CRKP. MDEO could inhibit CRKP biofilm formation. MDEO could also cause irreversible damage to the CRKP cell membrane, resulting in the leakage of biological macromolecules (protein, ATP) and the reduction of intracellular enzymes (AKP) activities. Finally, MDEO affected the pathways of respiratory metabolism, such as PPP and TCA pathways. MDEO could reduce the activity of key enzymes (Glucose-6-phosphate dehydrogenase, citrate synthase, isocitrate dehydrogenase, and alpha-ketoglutarate dehydrogenase) in the PPP and TCA pathways to exert its biological effects against CRKP. These results suggest MDEO can exert inhibitory effects on CRKP, and potential mechanisms of action including inhibition of biofilm formation, damage of cell membrane structure and inhibition of energy metabolism.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Understanding the relationship between the defects and properties could give the guidance to tailor the materials by virtue of regulating defects. In the present research, β-SiC nanowires (NWs) with ...different states of stacking faults have been fabricated by varying the heating temperature. The stacking fault states are characterized by transmission electron microscope and powder X-ray diffractometer. The electronic structures are investigated by X-ray absorption near-edge structures (XANES) at C K-edge and Si K-edge. Microstructural analysis revealed that the content of stacking faults in SiC NWs decreased significantly with an increase of heating temperature. The unoccupied density of states (DOS) in the C K-edge XANES spectra positively correlated with stacking fault contents in SiC NWs. The stacking fault planes were inclined at an angle of 35° to the growth direction at a heating temperature of 1400 °C, which were converted to perpendicular to the growth direction as the temperature increased to 1600 °C. The inclined stacking fault planes in the domain induced strongest dielectric resonance. The SiC NWs synthesized at 1400 °C with the highest carbon unoccupied DOS possess the most stacking fault content and numerous dipoles, which result in extensive polarization and energy dissipation under an altering electromagnetic field. As a result, a lowest reflection loss (
R
L
) value of −30 dB and an effective absorption band (
R
L
< −10 dB) covering a frequency range of 3.7 GHz were achieved.
SiC nanowires with a higher carbon unoccupied DOS possess more stacking faults, resulting in extensive energy dissipation under electromagnetic radiation.
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