Search

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]

[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.

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]

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]