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•Industrial installations for eliminating dioxins from flue gas.•Mechanisms of catalytic oxidation of chloroaromatics.•Catalyst classification and adaptation.•Catalyst deactivation ...and possible regeneration.•Miscellaneous methods to improve the catalytic oxidation process.
Commercial catalysts for the catalytic oxidation of chloroaromatics are mainly based on either noble metals or transition metal oxides supported on a suitable carrier. This paper reviews studies relative to these two generic groups of catalysts and their performances for chloroaromatic decomposition, i.e. conversion efficiency, stability and selectivity towards harmless products (e.g., CO2), and in particular, avoiding the formation of polychlorinated by-products. The various approaches towards improved catalysts, including tuning the support, adding dopants or promoters, improving the preparation methods, or auxiliary means such as the introduction of ozone (O3) or hydrogen peroxide (H2O2) in the gas to be treated, and combination with non-thermal plasma treatment are systematically reviewed. This review also appraises various modes of deactivation (i.e., originating from fouling, coking, poisoning, sintering of the catalyst, and from volatilization of its active phases) as well as possible methods for regeneration.
Houses mean a lot to Chinese people, and in the context of the urban-rural dualist system, town housing has a special significance for rural-urban migrants. Based on the 2017 China Household Finance ...Survey(CHFS) data, this study uses the Ordered Logit (OLogit) model to empirically test the effect of owning commercial housing on the subjective well-being(SWB) of rural-urban migrants, and through the mediating effect and moderating effect to conduct an in-depth investigation into the intrinsic effect mechanism and further explains the relationship between the two and the current residential location of their family. The results of the study show that: (1) Owning commercial housing can significantly enhances the subjective well-being(SWB) of rural-urban migrants, and the findings remain robust after using alternative model, adjusting the sample size, correcting for sample selectivity bias using propensity score matching(PSM), and controlling for potential endogeneity bias combining instrumental variables and conditional mixed process(CMP); (2) The effect of owning commercial housing on the subjective well-being(SWB) of the first generation rural-urban migrants, rural-urban migrants in the eastern and central regions, and those who obtained housing before the rapid rise in house prices is more pronounced; (3) Commercial housing acts on the subjective well-being(SWB) of rural-urban migrants through the mediating effect of housing assets, and there is some regional variation in the mediating effect of housing assets. At the same time, the household debt acts as a positive moderator between commercial housing and the subjective well-being(SWB) of rural-urban migrants; (4) Even with commercial housing, rural-urban migrants whose families are currently living in rural areas still have a stronger sense of subjective well-being (SWB).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
As a significant biomarker of prion diseases, ultrasensitive assay of infectious isoform of prion (PrPSc) is highly desirable for early diagnostics of prion diseases. Herein, taking normal cellular ...form of prion (PrPC) as a model owing to a high risk of pathogenicity of PrPSc, a new photoelectrochemical immunosensor has been developed based on hemin-induced switching of photocurrent direction. In the presence of PrPC, nitrogen-doped porous carbon-hemin polyhedra labeled with secondary antibody were introduced onto the CdS-chitosan (CS) nanoparticles-modified indium–tin oxide (ITO) electrode via the antigen–antibody specific recognition. Because of the matched energy level between CdS and hemin, the high-efficiency switch of photocurrent direction of the ITO/CdS-CS photoelectrode from anodic to cathodic photocurrent was observed even at very low concentration (0.4 aM) of PrPC. Through changing the specific antibody, this method can be easily expanded to PrPSc assay. Such low detectable limit is very useful in the early diagnosis and screening of prion diseases. The developed method has also promising applications in bioanalysis, disease diagnostics, and clinical biomedicine.
•A new photoelectrochemical immunosensor for ultrasensitive assay of prion protein.•Hemin-induced photocurrent direction switching of the ITO/CdS-CS photoelectrode.•Prion protein was determined at very low concentration (0.4 aM).
Herein, a new photoelectrochemical (PEC) biosensor based on a photocurrent direction switching system and target-triggered strand displacement amplification strategy was developed for the sensitive ...detection of microRNA (miRNA)-155, and it showed excellent selectivity and a low detection limit of about 49 aM.
Vibration-based condition monitoring among all the components of the aircraft structure is an important approach to improve the flight safety before any component in aircraft reaches resonance. This ...paper presents multichannel and multihop low-power wide-area network (MCMHL) architecture suitable for vibration monitoring on aircraft. First, microelectro mechanical system-long Range (LoRa)-based sensor node architecture in light of hardware cross-layer algorithm is proposed for implementing the tradeoff among hardware cost, power consumption, and performance. To achieve high accuracy of synchronous acquisition, multihop slot segmenting scheduling and multichannel data communication algorithm are proposed. In addition, the beacon transmission delay, of beacon between sink and sensor nodes is calculated, and further synchronization compensation algorithm is designed. The experiments of the proposed approach in aircraft vibration test and data synchronization test on aircraft skin are validated, showing that the proposed MCMHL approach has these abilities of data synchronous collections, remote communication, and data stream uploading in a wide monitoring area.
As an essential enzyme highly associated with various human diseases, alkaline phosphatase (ALP) plays an important role in human tissues. Developing new materials and strategies for monitoring ALP ...is thus important. We have developed a novel label-free fluorescent sensing system for ALP activity that is based on the “turn-on” fluorescence of VS
2
quantum dots. The fluorescence of VS
2
quantum dots quenched by Fe
3+
can be restored by ascorbic acid, which is generated by hydrolysis of
l
-ascorbic acid 2-phosphate catalyzed by ALP. Rapid, convenient, and sensitive detection of ALP is achieved in the range from 3 to 1000 U/L (
R
2
=0.9985), with a detection limit of 0.27 U/L. The proposed sensor exhibits excellent selectivity for ALP compared with other enzymes and proteins, such as glucose oxidase, lysozyme, trypsin, human serum albumin, and bovine serum albumin. The reliability for ALP determination in human serum plasma has been demonstrated with satisfactory recovery, revealing promising application in clinical diagnosis and biomedical research.
Graphical abstract
Hydrothermally synthesized VS
2
quantum dots serving as a novel turn-on fluorescent probe for detection of alkaline phosphatase (ALP) activity. AA
l
-ascorbic acid, AAP
l
-ascorbic acid 2-phosphate, NAC
N
-acetyl-
l
-cysteine
The high toxicity and low volatility of PCDD/Fs prevent detailed study of their catalytic degradation removal characteristics. In this study, 1,2-dichlorobenzene (1,2-DCBz) was initially used as a ...model to investigate the catalytic characteristics of various vanadium-based catalysts prepared by different methods. Then, the optimized catalyst was used for catalytic degradation of real PCDD/Fs at low temperatures based on a self-made stable source. The VO
x
/TiO
2
catalysts synthesized by the mechanochemical method (VTi-MC2) had a higher 1,2-DCBz removal efficiency (>85%) and stability (> 420 min) at low temperatures (< 200 °C) compared to VTi-SG (sol-gol method) and VTi-WI (wetness impregnation method). The physicochemical properties of catalysts were studied using comprehensive characterization. It was found that the VTi-MC2 has better VO
x
species distribution and possesses the highest V
5+
species and surface adsorbed oxygen content, which are the key factors that contributed to the higher removal efficiency. Accordingly, the mechanochemical method can be used to control the physicochemical properties of catalysts by adjusting the milling parameters. The optimum ball milling time is 2 h and a suitable precursor is NH
4
VO
3
for VO
x
/TiO
2
. Moreover, the removal efficiency and catalytic degradation efficiency of PCDD/Fs in gas phase catalyzed by VTi-MC2 were 97% and 50% respectively, within a range of temperatures below 200 °C, which are both higher than those reported research. In general, the mechanochemical strategy employed in this study provides a means for seeking more efficient catalysts used for low-temperature degradation of various trace organic pollutants.
This study develops a fault detection device for the fiber Bragg grating (FBG) sensing system and a fault detection method to realize the rapid detection of the FBG sensing system on airplanes. ...According to the distribution of FBG sensors on airplanes, the FBG sensing system is built based on wavelength division multiplexing (WDM) and space division multiplexing (SDM) technologies. Furthermore, the hardware and software of the fault detection device and the relevant FBG demodulator are studied in detail. Additionally, in view of the similar features of the healthy FBG sensor in the same measuring point, a rapid fault diagnosis method based on a synthetical anomaly index is proposed. The features (light intensity I, signal length L, standard deviation of original sample σ and energy value in time-domain P) of FBG sensors are extracted. The aggregation center value of the above feature values is obtained through the loop iteration method. Furthermore, the separation degrees of features are calculated and then form the synthetical anomaly index so as to make an effective diagnosis of the state of the FBG sensor. Finally, the designed fault detection instrument and proposed fault detection method are used to monitor the 25 FBG sensors on the airplane, the results indicated that three faulty and two abnormal FBG sensors on the airplane are identified, showing the effectiveness of the proposed fault detection method.
Herein, based on DNAzyme-induced disassembly of the “Z-scheme” TiO2/Au/CdS QDs system, a facile and sensitive photoelectrochemical biosensor was developed for lead ion assay and a low detection limit ...of 0.13 pM was obtained.
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