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Sludge viscosity expansion has always been a difficulty in the operation control of A2O process. The sludge viscosity expansion problem occurred in a sewage treatment plant in Zhengzhou City, resulting in poor sludge settling performance with SVI gradually increasing to about 240 mL/g and the mud level of the secondary sedimentation tank continuing to rise. The reasons of sludge swelling were analyzed from the aspects of inlet water quality, water temperature, aeration rate and scum. And then some measures such as adjusting the residual sludge discharge, sludge age, dissolved oxygen value, reflux ratio, hydraulic residence time were timely adopted, so that the sludge bulking problem was alleviated to a certain extent. In order to eliminate the floating mud in the biological tank, 40 mg/L cationic polymer flocculant was added to the distribution well of the secondary sedimentation tank. After a period of time, the sedimentation performance of the sludge was obviously improved with the SVI gradually decreasing to the normal level of about 120 mL/g, indicating that the problem of sludge viscosity swelling and eliminated the floating mud in the biological tank was solved. It provides a way to solve the viscous swelling of sludge.

Based on the self-polymerization reaction of dopamine (DA), a polydopamine (PDA) film was formed on the surface of silver nanoparticles (AgNPs) and glassy carbon electrode (GCE), which could result in uniform dispersion of AgNPs on the surface of GCE. As a result, PDA@AgNPs/GCE modified electrode was obtained. The self-polymerization time of DA and the electrochemical test method and conditions for chlorpromazine were investigated and optimized to establish a rapid method for the detection of chlorpromazine based on square wave voltammetry. The modified electrode was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Under the optimal conditions, the oxidation peak current of chlorpromazine on PDA@AgNPs/GCE had a good linear relationship with its concentration in the range of 5.0 × 10-8–1.0 × 10-5 mol/L (R2 = 0.991). The detection limit (RSN = 3) was 1.7 × 10-8 mol/L. The recoveries of chlorpromazine in spiked pork, chicken and beef samples were 84.9%–88.8%, 79.8%–93.8% and 80.6%–93.9%, respectively. The instrument used in the method was light and portable, and the preparation method of the modified electrode was simple, easy, cheap, and convenient for batch preparation of modified electrodes, and could be used for the rapid detection of chlorpromazine in livestock and poultry meat.

This paper explores whether university–industry collaboration can facilitate university technology license with the moderating effects of external and internal environments. Here, the university technology license is measured by the license of university non-collaborative-patent. We set up panel data during 2010–2016 of 118 top universities in China and adopted negative binomial regression for empirical analysis. Results show that university–industry collaboration is positively related to non-collaborative-patent license and market for technology has no moderating effect while the R&D strength can moderate the relationship. Specifically, funding has a positive effect on non-collaborative-patent license while research full-time equivalent of R&D personnel negatively moderates the relationship between collaboration and non-collaborative-patent license. This paper creates a new direction to study influencing factors of university technology license from the perspective of collaborators and environment and verified the driving effect of university–industry collaboration on university technology license. Moreover, it sheds light on theoretical streams of university technology license in developing countries. [ABSTRACT FROM AUTHOR]

The sensitive detection of ammonia at room temperature is crucial for both the chemical industry and human health. In this study, phosphorized NiMo layered double hydroxide (NiMo-P)-modified MXene-based composite materials were prepared using a combination of hydrothermal and calcination processes. A two-dimensional (2D)/2D van der Waals heterojunction formed between the MXene and NiMo-P phases facilitated the interlayer shuttling of charge carriers during gas adsorption. Furthermore, the composite material acquired abundant acidic sites during phosphorization, which fundamentally enhanced its NH3 sensing performance. In addition, the morphology of the composite was effectively controlled by tuning the poly-(methyl methacrylate). The hollow microspherical MXene@NiMo-P (MX-s@NiMo-P) composite material demonstrates highest sensing response to NH3. At 25 °C and 45% relative humidity (RH), the response of MX-s@NiMo-P to 100 ppm of NH3 was as high as 188.9%. After 30 d, the gas-sensing performance of the MX-s@NiMo-P sensor reached 93.4% of the initial value, highlighting its long-term stability over the 30-d period. This study describes an effective approach to improve the response of MXene-based gas sensor with long-term stability. [ABSTRACT FROM AUTHOR]