To establish a new method of testing and evaluating the quality of refined montan wax (RMW), digital color and GC fingerprint technology were introduced and applied. CIE Lab color mode was used to digitize the exterior colors of RMW, and the score obtained through a fitting function was also used to reflect its quality. It is shown that they were in complete accord with the human visual perception trend. The GC fingerprint was used to characterize the internal chemical information of RMW, and the composition of its internal features was reflected through the relative retention time (RRT) and relative peak area (RPA) values. It is shown that there was a high degree of similarity between the fingerprints, while certain differences also existed. This can be used to implement effective application of RMW to aspects such as quality control, adulteration identification, and origin attributions.
Considering COVID-19 epidemic prevention and control, education materials were excavated and refined, such as chemical disinfectants, typical drugs used in clinical treatment or trial and materials for preparation of medical protective equipment. We have carried out thematic teaching on "The important role of chemistry in the fight against COVID-19 epidemic", and integrated ideological and political education into the thematic teaching. Through thematic teaching, we can make students feel the charm of chemistry subject, stimulate students' interest in learning chemistry, fully mobilize students' learning enthusiasm and initiative, strengthen students' confidence and courage to overcome difficulties, cultivate the students' professional disciplines literacy and scientific literacy, activate students' love for the motherland, the people and the Communist Party of China. 相似文献
Effective performance management is critical to efficient supply chain management systems with the balanced scorecard as well as to effective evaluation models and their algorithms. Problems often encountered in the modeling of the balanced scorecard for supply chain are how to overcome the multicollinearity in its index system. In this paper, a new fuzzy hierarchical evaluation model featuring the criteria of the balanced supply chain scorecard is proposed and analyzed on the basis of data about Chinese firms. The model, based on the fuzzy weight’s matrix derived from a fuzzy principal component analysis, overcomes the multicollinearity in the index system of the balanced supply chain scorecard. This method proves good performance in determining the weight distribution matrix of the fuzzy hierarchical evaluation and improves the evaluation accuracy and generalization as shown for a group of firms in western China. 相似文献
This work reported an efficient electrochemical treatment for drinking water disinfection using a pyrolytic graphite electrode modified with ferrocenyl tethered poly(amidoamine) dendrimers–multiwalled carbon nanotubes–chitosan nanocomposite. The influence parameters of electrochemical disinfection of Escherichia coli and Staphylococcus aureus, such as applied potential and sterilization time, were investigated. Further investigation indicated that almost all (99.99 %) of the initial bacteria were killed after applying a low potential of 0.4 V for 10 min. During the electrochemical disinfection process, the oxidized form of ferrocene was formed on electrode, which played a key role in the disinfection towards E. coli and S. aureus. Hence, the proposed method may provide potential application for the disinfection of drinking water.
Figure
Schematic diagram of electrochemical disinfection progress 相似文献
We describe a rapid and convenient colorimetric method for the detection of oxidative DNA damage caused by peroxynitrite (ONOO?) using unmodified gold nanoparticles (AuNPs). AuNPs are stable in the presence of single-stranded DNA (ssDNA) against the aggregation induced by a high ionic strength. If adsorbed ssDNA are cleaved by ONOO? to form smaller fragments, the AuNPs rapidly aggregate due to electrostatic attraction. As a result, the color of the solution changes from red to blue, and this can be seen with bare eyes. We also have evaluated the activity of the antioxidants gallic acid, ascorbic acid and caffeic acid to scavenge ONOO?. This method therefore also can be applied to screen for anti-oxidation drugs and agents.
Figure
ONOO?-induced ssDNA cleavage can be visually detected by a red-to-blue color change of AuNPs. 相似文献
The photoactivity of CdS nanorods was greatly improved by amino functionalized accordion-like MXene and spherical ZnSnO3. MXene possesses good electron transfer capability and ZnSnO3 presents matched energy band with CdS, which deeply accelerate the electron transfer and prevent the recombination of photogenerated electron-hole pair, leading to a strong photoelectrochemical (PEC) response. Taking the merit of the improved photoactivity of CdS nanorods, a novel PEC biosensor was constructed for DNA hydromethylation detection based on immune recognition of target molecule, where 5-hydroxymethyl-2′-deoxycytidine triphosphate (5hmdCTP) was employed as detect target, CdS/MXene was used as photoactive material, and ZnSnO3 was adopted as signal amplification unit. Under enzymatic covalent reaction of –CH2OH of 5hmdCTP with –NH2 of MXene, 5hmdCTP was specifically recognized and captured. Then, taking advantages of the covalent reaction between phosphate group of 5hmdCTP and ZnSnO3, the signal amplification unit was captured. Under the optimum conditions, this PEC biosensor presents wide linear range of 0.008–100 nM and low detection limit of 4.21 pM (3σ). The applicability of the developed method was evaluated by investigating the effect of Cd2+ and perfluorohexane compound pollutant on 5-hydroxymethylcytosine content in the genomic DNA of the roots and leaves of wheat seedlings. 相似文献