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For obtaining environment-friendly and efficient green corrosion inhibitors， the photinia leaf extracts (PTF) were prepared by distilled water reflux method.The corrosion inhibition performance of PTF on Q235 steel in 1 mol/L hydrochloric acid was studied using electrochemical tests， weight loss tests， scanning electron microscopy and other methods.Results showed that as a mixed corrosion inhibitor， PTF could effectively inhibit the corrosion of Q235 steel in hydrochloric acid medium.The corrosion inhibition efficiency increased with the increase of PTF concentration and decreased with the increase of solution temperature.Furthermore， the inhibition efficiency of 4 g/L PTF was 87.99%at 293 K.The results of adsorption isotherm model showed that PTF could spontaneously adsorb on the surface of Q235 steel through physical effects， which conformed to the Langmuir single-layer adsorption model.

Covalent organic frameworks (COFs) have emerged as compelling interface optimizer candidates for competent perovskite solar cells (PSCs). However, there is a notable absence of rationally designed COFs tailored for perovskite and hole transporting layers (HTLs). Herein, an unreported one-dimensional (1D) triarylamine-based covalent organic framework (COF) {[(TPA)2(TPB)1]–C＝N–} with active amino groups was first synthesized. To anchor COF on the perovskite surface and manipulate the interface hole transportation, this 1D COF was salified with hydrogen halides to produce {[(TPA)2(TPB)1]–C＝N–-X} (COF-X; X = Cl, Br, and I). The ammonium terminals (–NH3+) can coordinate with perovskite via strong ionic interaction. The backbone units of triphenylamine (TPA) and N,N,N′,N′-tetraphenylbenzidine (TPB), renowned for their superior hole extracting and transporting properties, can enhance the hole mobility of the perovskite film from 1.02 to 3.72 cm2 V−1 s−1. Consequently, the optimal device achieved a power conversion efficiency (PCE) of 23.58% and an impressive open-circuit voltage (VOC) of 1.181 V. Additionally, the unencapsulated devices retained 90.8% and 89.2% of their initial efficiencies after atmospheric storage over 4800 hours and continuous illumination over 500 hours, respectively. [ABSTRACT FROM AUTHOR]

A series of single phase (Na1/2Eu1/2)xCa1−xCu3Ti4O12 (x = 0, 0.01, 0.05, 0.1, 0.2, 0.3, 0.35, 0.4 and 0.45) ceramics with different doping amounts were successfully prepared by high temperature solid-state reaction method. The microstructure, ion valence, and dielectric properties of the ceramics were systematically studied. The results indicated that with the increase of Na+ and Eu3+ ions concentration in (Na1/2Eu1/2)xCa1−xCu3Ti4O12 ceramics, Na and Eu elements accumulated at the grain boundaries of ceramics, thereby increasing the insulation of grain boundaries and effectively reducing the dielectric loss of the ceramics. However, the presence of Cu+ in (Na1/2Eu1/2)xCa1−xCu3Ti4O12 (x ≥ 0.3) ceramics with high doping content could affect the polarization mechanism inside the ceramics and improve their dielectric properties. The dielectric constant of (Na1/2Eu1/2)0.3Ca0.7Cu3Ti4O12 ceramics was as high as 25 282, with a dielectric loss of 0.061 (at room temperature and 10 Hz), and it had good dielectric stability. [ABSTRACT FROM AUTHOR]

Pyraclostrobin is a new broad-spectrum methoxyacrylic acid fungicide. Cyazofamid is a new selective foliar spray acaricide. Here, we studied the degradation rate and final residues of pyraclostrobin and cyazofamid in grape and evaluated their dietary risk to consumers. The average recoveries of pyraclostrobin ether ester, cyazofamid and cyazofamid metabolite (CCIM) in grapes were 84–94%, 92–98% and 99–104%, respectively. The relative standard deviations (RSDs) were 6.0–20.3%, 2.4–10.5% and 1.3–4.0%, respectively, and the LOQs were all 0.05 mg/kg. The digestion dynamics of the experimental sites were in accordance with the first-order kinetic equation. The degradation half-lives of pyraclostrobin ether ester and cyazofamid were 17.8 d–28.9 d and 4.3 d–7.8 d, respectively. The final residues of pyraclostrobin ether ester, cyazofamid and CCIM in grapes were <0.05–1.88 mg/kg, <0.05–0.31 mg/kg and <0.05–0.47 mg/kg, respectively. Using probability models, the total chronic risk values for pyraclostrobin and cyazofamid were calculated to be 0.112–189.617% and 0.021–1.714%, respectively. The results of the contribution analysis indicate that pyraclostrobin poses a much greater risk to Chinese consumers than cyazofamid, especially to children and adolescents, who have a significantly greater risk than adults. This suggests that more consideration should be given to the cumulative risk of compounds for vulnerable groups in the future. [ABSTRACT FROM AUTHOR]

[Objectives] The bench test is an important means for the design and verification of steam systems,and the accuracy of the boundary condition is a critical factor for studying the characteristics of the bench test.[Methods] In order to propose a feasible dynamic flow boundary control method,based on the change requirements of steam inlet flow in the bench test of a steam system,the two schemes of PID closed-loop control and open-loop control are proposed,and simulation comparison and analysis are carried out. In the GSE simulation system,JTopmeret modules are employed to establish the whole steam test system,the optimization of the modules and correction of parameters are processed on the basis of the data detected in the steam test,and the simulation data is compared with the experimental data to verify the accuracy and validity of the simulation model.[Results] For the control requirements of reducing steam flow linearly by 20 t/h within 10 s,the simulation results show that the open-loop control scheme allows the control of boundary conditions to be achieved after several iterations,while using the traditional PID closed-loop control scheme makes it difficult to control the boundary as required. The test results show that the flow change at the steam inlet meets the test requirements of the bench test,and is consistent with the simulation results.[Conclusions] The results of this research can provide references for the boundary control of steam system bench tests.

Transmission electron microscopy (TEM) is an excellent characterization method to analyze the size, morphology, crystalline state, and microstructure of perovskite quantum dots (PeQDs). Nevertheless, the electron beam of TEM as an illumination source provides high energy, which causes morphological variation (fusion and melting) and recession of the crystalline structure in low radiolysis tolerance specimens. Hence, a novel and facile strategy is proposed: electron beam peel [PbBr6]4− octahedron defects from the surface of QDs to optimize the crystal structure. TEM and high-angle annular dark-field scanning TEM (HAADF) tests indicate that the [PbBr6]4− octahedron would be peeled from the surface of QDs when QDs samples were irradiated under high-power irradiation, and then a clear image would be obtained. To avoid interference from a protective film of "carbon deposits" on the surface of the sample when using high resolution TEM, amorphous carbon film (15–20 nm) was deposited on the surface of QDs film and then characterized by TEM and HAADF. The detection consequences showed that the defection of PbBr2 on the surface of QDs will gradually disappear with the extension of radiation time, which further verifies the conjecture. [ABSTRACT FROM AUTHOR]

α‐phase formamidine lead iodine (α‐FAPbI3) as a competitive candidate to pursue high‐performance perovskite solar cells (PSCs) suffers from the weakness of random nucleation and disordered growth in chasing high‐grade polycrystalline films. Here, single‐crystal seeds crystallization (SCSC) method is proposed to obtain high‐quality α‐FAPbI3 perovskite films for the first time. Six single‐crystals seeds (CsPbBr3, CsPbI3, FAPbBr3, FAPbI3, MAPbBr3, and MAPbI3) are employed to regulate α‐FAPbI3 perovskite crystallization. These seeds act as nucleation sites and allow the perovskite to grow directly. The rapid crystallization significantly improves the crystallinity of perovskite films with uniform morphology, large grain size, and less defects. Of particular note, FAPbBr3 seed prefers to grow α‐FAPbI3 epitaxially from FAPbBr3@PbI2 heterostructure through a halogen anion exchange process. The average grain size of FAPbBr3‐perovskite film is boosted to 2.6 µm, and the trap density reduced by 11 times. The resultant FAPbBr3‐PSCs achieve a maximum power conversion efficiency (PCE) of 23.84% with a high open‐circuit voltage of 1.18 V. The unencapsulated PSC retains 91% of the initial PCE after 3000 h of storage at ≈30–50% relative humidity and preserves 98.5% of the original value after 155 h illumination with maximum power point tracking. [ABSTRACT FROM AUTHOR]

CsPbBr3 quantum dots (QDs) prepared through traditional hot‐injection and room temperature reprecipitation methods are usually hexahedral (nanoplate/cube) and green‐emitting. These methods severely obstruct the development of blue perovskite‐based light‐emitting diodes (PeLEDs) because the resultant QDs always suffer unachievable morphology regulation. Here, highly efficient blue‐emitting rhombic dodecahedron CsPbBr3 QDs (CsPbBr3 <12> QDs) are obtained by regulating morphological transformation for the first time through a novel and facile sequential post‐treatment strategy. Hydrobromide (‐NH3+) with stronger adsorption energy promotes the morphology transform of QDs from nanoplate to cube by substituting oleylamine in the first step. Then, polar solvent vapor eliminates PbX64− and led to the (112) crystal plane of the cube QDs being exposed, which is effectively stabilized by ‐NH3+ to realize morphology transition from cube to the dodecahedron. Highly efficient 12‐faceted dodecahedrons are endowed with significantly enhanced photoluminescence quantum yield of 89.8% at 476 nm as well as uniform size distribution and mono‐dispersity. The target blue PeLEDs achieve the maximum external quantum efficiency of 6.6% (480 nm) and excellent spectrum stability. This study provides a new strategy to prepare blue‐emitting CsPbBr3 <12> QDs by delicate control toward the growth and polyhedron process of crystal. [ABSTRACT FROM AUTHOR]

Metalaxyl-M and azoxystrobin have been used to control various fungal diseases on scallion and other crops. In view of the adverse toxic effects of both on the mammalian liver, it is necessary to conduct a cumulative risk assessment of their dietary exposure to consumers. The residues of metalaxyl-M and azoxystrobin on scallion were determined by a quick, easy, cheap, effective, rugged, and safe method (QuEChERS) combined with high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The half-lives were about 1.15 and 3.89 days, respectively, and the final residues after a seven-day harvest interval were <0.001–0.088 mg/kg and 0.190–4.687 mg/kg, respectively. The cumulative dietary risk quotient of the two fungicides to Chinese consumers calculated by the probability model is 13.94%~41.25%. According to the results of the contribution analysis, the risk posed by azoxystrobin is much greater than that of metalaxyl-M. Although metalaxyl-M and azoxystrobin do not pose a cumulative risk to Chinese consumers, the risk to children and adolescents is significantly higher than that to adults. This suggests that in future research, more consideration should be given to the cumulative risk of compounds to vulnerable groups. [ABSTRACT FROM AUTHOR]

Tracing the herbicide bixlozone and its metabolites in food is necessary to assess their risks to human health. In the study, a rapid and effective analytical method using the quick, easy, cheap, effective, rugged, and safe method for the simultaneous determination of bixlozone and its metabolites (2,4‐dichlorobenzoic acid, 3‐hydroxy‐propanamide‐bixlozone, and 5′‐hydroxy‐bixlozone) in plant and animal samples (tomato, cucumber, apple, wheat flour, meat, milk, and egg) was developed based on ultra high performance liquid chromatography–tandem mass spectrometry. The method was validated based on the linearity (R2 > 0.99), sensitivity (limit of quantification = 0.01 mg/kg), recovery (70.2–115.1%), and precision (intraday 1.2–17.6%, interday 0.3–16.0%). Detection was achieved within 6.0 min. The method is reliable for the determination of four target compounds in all seven matrices. The satisfactory validation criteria and successful application show that the proposed methodology is suitable for the detection of four target compounds in real matrices. [ABSTRACT FROM AUTHOR]

A ratiometric fluorescence method based on carboxylated graphitic carbon nitride nanosheets (C-g-C3N4) and Eu3+ (C-g-C3N4-Eu3+) is described for the detection of tetracyclines (TCs), a broad-spectrum antibiotic. C-g-C3N4, which was used as a fluorescence enhancer of Eu3+, was prepared by direct pyrolysis of melamine and post-functionalization. In the presence of TCs, the fluorescence intensity of Eu3+ at 616 nm increased, accompanied by a decrease of fluorescence intensity of C-g-C3N4 at 435 nm. Under the optimal conditions, the ratio of fluorescence intensity at 616 nm to the one at 435 nm (I616/I415) increases linearly in the 10 nM to 40 μM TC concentration range with a detection limit of 7.7 nM (S/N = 3). It has been successfully applied in the detection of TCs in spiked tap water and soil samples with satisfactory recovery (96.6–107.2%) and high precision. Furthermore, a test paper and smartphone can assist in rapidly detecting TCs due to the emission color change from blue to red with the addition of TCs. This shows that the proposed method has great potential for the rapid detection TCs in real samples. [ABSTRACT FROM AUTHOR]

There have been more concerns over energy resource depletion and indoor comfort improvement along with the increased time spend in a building. Building operation requires more energy in the spaces of high occupancy density in public buildings in summer because most energy has been consumed to make the indoor environment comfortable. Therefore, there is a conflicting issue for optimization, which is minimum energy consumption vs. maximum indoor comfort. In this paper, the indoor comfort model was established based on the weights of the thermal environment and air quality. The indoor air temperature, indoor relative humidity and indoor CO2 concentration as KPI (Key performance indicators) are optimized dynamically according to different outdoor meteorological parameters and different indoor occupancy density by an improved multi-objective optimization method of Non-dominated Sorting Genetic Algorithm II (NSGA-II). A single suitable solution from the non-inferior solutions is selected by the method of fuzzy comprehensive decision. The single solution of those KPI can be used as the set point of air-conditioning controller. A case study was carried out and the corresponding simulation of optimization of energy and comfort was presented. The results showed that the methodology can achieve the maintenance of indoor comfort and energy consumption reduction. [ABSTRACT FROM AUTHOR]

To discern the distinctive effect of the C=C bond and the phenyl bridge on the photophysical and chemical properties of D–π–A molecular systems, three new dicyanovinyl substituted push–pull chromophores 1–3 containing either a C=C bond or a phenyl ring as the central π-linker were synthesized by the Suzuki–Miyaura and Knoevenagel reactions. Together with the counterpart of 1 developed by Zhang's group (TPE-z), their optical properties and single crystal structures were systematically and comparatively investigated. Notably, the simple π-extension of a C=C linker to a phenyl ring between electron donor and electron acceptor moieties could greatly affect the photophysical properties of chromophores, particularly leading to significant hypsochromic shifts in both absorption and emission spectra. Meanwhile, as a node of twisted sections in chromophores, the C=C bond was demonstrated to play an important role in the nonradiative relaxation of excited states, as compared to the rigid phenyl spacer. Moreover, the three chromophores were found to display spectral responses to hydrazine with slightly different sensitivities, and visual detection of hydrazine in the gaseous state was achieved via using readily fabricated paper test strips. [ABSTRACT FROM AUTHOR]

A catalyst system consisting of copper (I) chloride, sodium 2-picolinate (PIC) and TEMPO has been found to be effective in the aerobic oxidative conversion of benzylic alcohols with aqueous ammonia to nitriles in the absence of organic solvent. Various benzyl alcohols were converted to their corresponding nitriles in high yields. The ligand PIC can be easily removed from the reaction mixture due to its water solubility, allowing for easy product purification. [ABSTRACT FROM AUTHOR]

This study describes the development of a new methodology for assessment of indoor comfort in buildings. The assessment not only includes the objective environmental information but also subjective feeling information. It is based on the calculation of two indexes: objective assessment (OA) and subjective assessment (SA). The results of OA and SA are standardized in a unified scale by fuzzy fusion and adaptive fusion separately. Starting from the values of OA and SA indexes, both of them are integrated by fuzzy inference decision to comprehensive comfort results. The proposed method allows the classification of the indoor comfort level. The methodology would therefore help for an assessment in the context of building assessment, where satisfactory indoor conditions are sought, improving environmental and economic performance of the building. [ABSTRACT FROM AUTHOR]

Dissipation and residue levels of bifenthrin and chlorfenapyr in eggplant and soil under field conditions were investigated using gas chromatography coupled with an electron capture detector (GC-ECD). The mean recoveries of bifenthrin and chlorfenapyr were 85.2–104.9%, with relative standard deviations (RSDs) of 0.5–9.1%. The limit of quantification (LOQ) was 0.01 mg kg−1. Bifenthrin exhibited half-lives of 3.3 to 4.1 days in eggplant and 17.8 to 25.7 days in soil; the half-lives of chlorfenapyr were 3.5 to 3.8 days in eggplant and 21.7 to 27.7 days in soil. During harvest, the terminal residues of bifenthrin and chlorfenapyr were below 0.031 and 0.083 mg kg−1, respectively. Risk assessment for different groups of people in China was evaluated. The risk quotients (RQs) of bifenthrin and chlorfenapyr were ranged from 0.0068 to 0.0148 and from 0.0033 to 0.0072, respectively. These results may provide guidance on reasonable use of pesticides and serve as a basis for establishing maximum residue limits (MRLs) in China. [ABSTRACT FROM AUTHOR]

The polymerase chain reaction (PCR) has become an indispensable technique in molecular biology, however, it suffers from low efficiency and specificity problems. Developing suitable additives to effectively avoid nonspecific PCR reactions and explore the mechanism for PCR enhancing is a significant challenge. In this paper, we report three different modified gold nanoparticles (AuNPs) with different surface charge polarities and poly (diallyl dimethylammonium) chloride (PDDA) for use as novel PCR enhancers to improve the efficiency and specificity. These AuNPs included the positively charged PDDA protected AuNPs (PDDA-AuNPs), the neutral PDDA-AuNPs modified with excess chloride ion (PDDA.C-AuNPs), and the negatively charged sodium citrate (Na3Ct) protected AuNPs (Na3Ct-AuNPs). Our data clearly suggests that the positively charged PDDA-AuNPs with an optimum concentration as low as 1.54 pM could significantly enhance the specificity and efficiency of PCR, however, the optimum concentration of the negatively charged Na3Ct-AuNPs (2.02 nM) was more than 3 orders of magnitude higher than that of positively charged PDDA-AuNPs. The PCR specificity and efficiency are also improved by the neutral PDDA.C-AuNPs with an optimum concentration, much more than that of the PDDA-AuNPs. This suggests that there should be an electrostatic interaction between the positively charged PDDA-AuNPs and the negatively charged PCR components, and the surface charge polarities of PDDA-AuNPs may play an important role in improving the PCR specificity and efficiency. [ABSTRACT FROM AUTHOR]

DOI: 10.1002/jssc.202000992 The cover picture shows an analytical method for simultaneous determination of the novel herbicide bixlozone and its metabolites in plant and animal samples. Front Cover: Simultaneous determination of the herbicide bixlozone and its metabolites in plant and animal samples by liquid chromatography-tandem mass spectrometry We have investigated the extraction and purification procedures, chromatographic conditions, and mass spectrometer parameters to obtain the optimal sensitivity. [Extracted from the article]

Nominal (Ba1−xMgx)TiO3 (x = 0.015) (BM1T) and (Ba1−xMgx)TiO3 (x = 0.03–0.20) (BMT) ceramics were prepared by the mixed-oxide route at sintering temperatures (Ts) of 1200−1400 °C and 1200 °C, respectively. The solubility limit of Mg2+ in BMT was determined by XRD to be x = 0.05, and evidence was found for occupation of the A site by Mg2+. Electron paramagnetic resonance (EPR) was employed as a key technique to investigate the effect of Ts on oxygen vacancies in BM1T. The structure of BM1T changed from pseudocubic at Ts = 1200 °C to tetragonal at 1300 °C to mixed phases of hexagonal and tetragonal at 1400 °C. When Ts ≥ 1300 °C, a g = 1.956 EPR signal was observed at T = −188 °C and assigned as ionized oxygen vacancies. Mg2+ exhibited amphoteric behavior of substituting for the double cation sites. When Ts = 1400 °C, B-site Mg2+ and oxygen vacancies mainly existed in the hexagonal phase and A-site Mg2+ was dominant in the tetragonal phase. The higher tan δ was attributed to the higher concentrations of oxygen vacancies and Ti3+ in the hexagonal phase. [ABSTRACT FROM AUTHOR]