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Modulating the emission wavelength in the range of ultraviolet to deep‐blue with high color purity remains elusive. Herein, a versatile strategy is proposed from the perspective of rationally regulating nonbonding/π‐bonding character of frontier molecular orbitals to finely modulate emission colors while retaining superior color purity. By modifying the fused modes of indolo[3,2,1‐jk]carbazole (ICz) units, the proof‐of‐the‐concept emitters emphasize adjustable hybridization of nonbonding and π‐bonding characteristics, achieving a wide‐range color tuning range from ultraviolet (380 nm) to deep‐blue (428 nm) and small full‐width at half‐maximum (FWHM) of 8–33 nm (63–222 meV). Organic light‐emitting diodes based on the new emitter exhibit electroluminescence emission at 430 nm, a small FWHM of 44 nm (253 meV), maximum external quantum efficiency of 10.9%, and CIE color coordinates of (0.16, 0.05). The CIE coordinates are close to the National Television System Committee (NTSC) standard blue of (0.15, 0.06). [ABSTRACT FROM AUTHOR]

Homoleptic fac‐substituted Ir(III) carbene complexes exhibit higher emission energy (in purple region) in comparison to their mer‐counterparts, prohibiting them to be employed in fabrication of blue emissive organic light‐emitting diode (OLED) devices. Now, the design of two distinctive CF3‐functionalized purin‐8‐ylidene Ir(III) complexes, namely, m‐ and f‐CF3 and m‐ and f‐PhCF3, from new carbene motifs, 9‐(3‐(tert‐butyl)phenyl)‐7‐isopropyl‐2‐(trifluoromethyl)‐7,9‐dihydro‐8H‐purin‐8‐ylidene (A4) and 9‐(3‐(tert‐butyl)phenyl)‐7‐methyl‐6‐phenyl‐2‐(trifluoromethyl)‐7,9‐dihydro‐8H‐purin‐8‐ylidene (B7), having notably stabilized lowest unoccupied molecular orbital energy levels is reported. Hence, the corresponding f‐isomers f‐CF3 and f‐PhCF3 exhibit electroluminescence with peak max. at 478 and 495 nm, max. external quantum efficiencies (EQEs) of 10.4% and 12.8%, respectively. By using f‐CF3 as assistant dopant to convey its energy to terminal emitter t‐DABNA and from f‐PhCF3 donor to 2TCzBN acceptor, two hyper‐OLED devices are successfully fabricated, giving high max. EQE of 23.8%, full‐width at half‐maximum (FWHM) of 30 nm, and CIEx,y coordinate of (0.13, 0.14) for the acceptor t‐DABNA, and max. EQE of 24.0%, FWHM of 28 nm, and CIEx,y of (0.11, 0.36) for the acceptor 2TCzBN, confirming the advantages of these purin‐8‐ylidene Ir(III) complexes. [ABSTRACT FROM AUTHOR]

Four isomeric, homoleptic iridium(III) metal complexes bearing 5‐(trifluoromethyl)imidazo[4,5‐b]pyridin‐2‐ylidene and 6‐(trifluoromethyl)imidazo[4,5‐b]pyridin‐2‐ylidene‐based cyclometalating chelates are successfully synthesized. The meridional isomers can be converted to facial isomers through acid induced isomerization. The m‐isomers display a relatively broadened and red‐shifted emission, while f‐isomers exhibit narrowed blue emission band, together with higher photoluminescent quantum yields and reduced radiative lifetime relative to the mer‐counterparts. Maximum external quantum efficiencies of 13.5% and 22.8% are achieved for the electrophosphorescent devices based on f‐tpb1 and m‐tpb1 as dopant emitter together with CIE coordinates of (0.15, 0.23) and (0.22, 0.45), respectively. By using f‐tpb1 as the sensitizing phosphor and t‐DABNA as thermally activated delayed fluorescence (TADF) terminal emitter, hyperluminescent OLEDs are successfully fabricated, giving high efficiency of 29.6%, full width at half maximum (FWHM) of 30 nm, and CIE coordinates of (0.13, 0.11), confirming the efficient Förster resonance energy transfer (FRET) process. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) materials that can exhibit high efficiencies in non‐doped organic light‐emitting diodes (OLEDs) are highly desired. On the base of a reference TADF molecule (4‐(9,9‐dimethylacridin‐10(9H)‐yl)phenyl)(phenyl)methanone (BP‐DMAC) containing benzoyl/acridine as acceptor/donor, 9‐phenyl‐9H‐3,9"‐bicarbazole (PBCz) is incorporated to the benzoyl side to design and develop a novel emitter, (4‐(9,9‐dimethylacridin‐10(9H)‐yl)phenyl)(9‐phenyl‐9H‐[3,9″‐bicarbazol]‐6‐yl)methanone (PBCz‐BP‐DMAC). The introduction of PBCz unit is proved to endow PBCz‐BP‐DMAC the additional self‐host feature, in addition to its original aggregation‐induced emission and TADF characters. As a result, the non‐doped OLED of PBCz‐BP‐DMAC exhibits sky‐blue emission with remarkable external quantum efficiency (EQE) of 23.0% and rather low efficiency roll‐off (6%) at a brightness of 1000 cd m−2, while its doped device reveals a maximum EQE of 27.5%; the spectra and color coordinates of the doped and non‐doped devices are almost identical. It also acts as a host to sensitize green iridium phosphor (fac‐tris(2‐phenylpyridine) iridium(III), Ir(ppy)3) with high EQE of 23.6%. More fascinatingly, the simplified single‐emitting‐layer all‐TADF white OLED utilizing PBCz‐BP‐DMAC as host emitter in combination with an orange TADF emitter (4CzTPN‐Ph) realizes a state‐of‐the‐art EQE of 20.6%. Evidently PBCz‐BP‐DMAC is one of the best sky‐blue TADF materials and exhibits multi‐functional applications in OLEDs with excellent performance. [ABSTRACT FROM AUTHOR]

The stabilization of black-phase formamidinium lead iodide (a-FAPbI3) perovskite under various environmental conditions is considered necessary for solar cells. However, challenges remain regarding the temperature sensitivity of a-FAPbI3 and the requirements for strict humidity control in its processing. Here we report the synthesis of stable a-FAPbI3, regardless of humidity and temperature, based on a vertically aligned lead iodide thin film grown from an ionic liquid, methylamine formate. The vertically grown structure has numerous nanometer-scale ion channels that facilitate the permeation of formamidinium iodide into the lead iodide thin films for fast and robust transformation to a-FAPbI3. A solar cell with a power-conversion efficiency of 24.1% was achieved. The unencapsulated cells retain 80 and 90% of their initial efficiencies for 500 hours at 85°C and continuous light stress, respectively. [ABSTRACT FROM AUTHOR]

Purpose To characterize and compare children with correct diagnosis (CD) and misdiagnosis (MD) of tracheobronchial foreign body (TBFB). Methods A retrospective study was performed to review the medical records of children with CD group and MD group of TBFB. CD was defined when TBFB was identified during the first hospital visit. Otherwise, MD was considered. Demographic information, including gender, age, and clinical information, including clinical presentations and characteristics of foreign bodies, were retrieved. These characteristics were compared between two groups by Student's t-test or Wilcoxon two-sample test, or Chi-square analysis or Fisher's exact test, when appropriate. Results A total of 462 children with final diagnosis of TBFB were identified, with 276 children having CD and 186 children having MD. The most common location to identify the TBFB was right main bronchus in both CD and MD groups. Children with the previous history of respiratory tract foreign body were more likely to receive the CD. Children in MD group were more likely to have fever, as well as wheezing and crackles during physical examination. They were more likely to have pneumonia. Most common TBFB were peanuts. The majority of the TBFB were removed by the flexible bronchoscope coupled with forceps. Conclusion Careful history taking and physical examination, especially for those children with unclear causes for their pneumonia or asthma, or children with no improvement on the treatments, should be performed to rule out the possibility of TBFB. Bronchoscopy should be performed if necessary. [ABSTRACT FROM AUTHOR]

• Nonlinear thermoacoustic instability is studied under broad conditions. • Five kinds of stable or unstable flame modes are observed. • Hopf bifurcations for the instability are captured either by changing U in or Φ. • Appearance of ORZ flame is expected to trigger the instability. • Stable combustion regime is wider with lower swirl number S. The nonlinear behavior of thermoacoustic oscillation for premixed swirl flames fueled with CH 4 /air mixtures is experimentally studied by changing the equivalence ratio Φ , combustor inlet bulk velocity U in and swirl number S. The nonlinear dynamic characteristics of the system are analyzed by the methods of phase space reconstruction, recurrence plot, Poincaré section and 0–1 test for chaos. Five kinds of flame modes are observed in the combustion system with the change of Φ , U in , and S , which are lean/rich blow-off, stable combustion, quasi-periodic oscillation, and limit cycle oscillation. Subcritical Hopf bifurcation of the oscillation is captured either by changing Φ or U in , and Φ and U in are found to have similar effects on the flame mode transition under specific operating conditions. It is observed that the appearance of flame in the outer circulation zone (ORZ) and the enhancement of its burning intensity are matched with the occurrence of quasi-periodic and limit cycle oscillations, respectively. It is examined that the lean/rich blow-off limits and oscillation range are extended with a larger S , and the stable combustion regime is wider with a smaller S. This study contributes to understanding the nonlinear thermoacoustic instability of swirl flames under broad flame conditions, which helps to develop effective instability prediction and control methods in stable, efficient, and low-emission gas turbines. [ABSTRACT FROM AUTHOR]

The largely twisted intramolecular charge transfer (TICT) framework is the most commonly adopted strategy for constructing thermally activated delayed fluorescence (TADF) molecules. By increasing the dihedral angle between the donor and acceptor, a small singlet–triplet energy splitting (ΔEST), high reverse intersystem crossing rate (kRISC) and large proportion of delayed emission can be achieved simultaneously. Five twisted molecules, tCPT, Ph-tCPT, o-PhCz-tCPT , p-PhCz-tCPT and 3-PhCz-tCPT, are designed and synthesized combining cyaphenine and 3,6-di-tert-butyl-9H-carbazole or its derivatives. Phenyl (Ph) and N-phenyl carbazole (N-PhCz) are introduced to the 1-site of 3,6-di-tert-butyl-9H-carbazole to design the donor units, with the expectation to tune the dihedral angle between the donor and acceptor and the frontier molecular orbital distribution. As a result, the ΔEST decreases from 0.30 eV for tCPT to 0.20 eV for 3-PhCz-tCPT, and the delayed fluorescence (DF) proportion increases from 19.5% for tCPT to 31.9% and 37.3% for o-PhCz-tCPT and 3-PhCz-tCPT. Organic light-emitting diodes (OLEDs) using these molecules as doped emitters exhibit pure blue emission with the peaks at 456–466 nm. The emitters with higher DF proportions show higher electroluminescence efficiencies, e.g. 13.8 and 16.4 cd A−1 for o-PhCz-tCPT and 3-PhCz-tCPT devices, respectively, representing an efficiency increase by 10% relative to tCPT. It is demonstrated that incorporation of bulky substituents at the 1-site of carbazole is an effective and practical way to facilitate RISC and enhance the DF proportion of blue TADF materials. [ABSTRACT FROM AUTHOR]

Blue iridium phosphors are always precious and desirable for both fundamental research and industrial applications in organic light-emitting diodes (OLEDs). Three heteroleptic cyclometalated iridium(III) complexes, namely, Ir1, Ir2 and Ir3, incorporating 2-(3,5-bis(trifluoromethyl)phenyl)-pyrimidine (tfmphpm) or 2-(2,4-difluorophenyl)-pyrimidine (dfppm) as the main ligand, and 2-(3-(trifluoromethyl)-1H-pyrazol-5-yl)pyridine (fppz) or 2-(5-(4-(trifluoromethyl)phenyl)-2H-1,2,4-triazol-3-yl)pyridine (Htaz) as the ancillary ligand, were developed for application in OLEDs. Owing to the introduction of the strong-field CF3-containing ancillary ligand and the incorporation of electron-withdrawing F or CF3 groups on the HOMO-lying C-related aromatic rings of the C^N cyclometalating ligands, the phosphorescence of these Ir(III) complexes peaked at 457–459 nm. In comparison with the well-known commercial sky-blue iridium complex FIrpic (bis(4′,6′-difluorophenylpyridinato) iridium(III) picolinate, 475 nm), the phosphorescence of these complexes is hypsochromically shifted by 16–18 nm, more closely approaching standard blue light. They have high phosphorescence quantum yields in solution. The phosphorescent OLEDs employing these complexes as doped emitters display impressive performance. In particular, the PhOLED based on Ir3 achieves an outstanding maximum external quantum efficiency of 21.23% with Commission Internationale de l'Eclairage (CIE) coordinates of (0.15, 0.26), which is about 27% higher than that of the control device using FIrpic as a dopant (16.63%). [ABSTRACT FROM AUTHOR]

To explore the correlation of the acceptor electron affinity and the molecular conformation to the thermally activated delayed fluorescence (TADF) feature, a series of d‐π‐A molecules were designed and synthesized with triazine (Trz) as the acceptor (A) and carbazole (Cz) or tert‐butylcarbazole (BuCz) as the donor (D). On the phenylene bridge between D and A, methyl or trifluoromethyl was incorporated close either to D or to A to tune the molecular conformation and the electron‐withdrawing ability of acceptor. Both the twist angles and the singlet and triplet energy difference (ΔEST) were observed strongly dependent on the type and position of the substituent on the π‐bridge. Only those molecules with trifluoromethyl locating close to the D side, namely TrzCz‐CF3 and TrzBuCz‐CF3, exhibit TADF feature, verifying that both sufficient electron affinity of the A unit and large dihedral angle between D and the π‐bridge are necessary to ensure the occurrence of TADF. The blue organic light‐emitting diodes fabricated with TrzCz‐CF3 and TrzBuCz‐CF3 achieved external quantum efficiencies of 9.40 % and 14.22 % with CIE coordinates of (0.19, 0.23) and (0.18, 0.29) respectively. This study provides practical design strategy for blue TADF materials particularly when planar and less crowded group is used as donor. [ABSTRACT FROM AUTHOR]

Background: Statin has been more and more widely used in chronic liver disease, however, existed studies have attained contradictory results. According to the present study, we aimed to test the efficacy and safety of statin via a meta-analysis.Methods: Different databases were searched for full-text publication based on inclusion and exclusion criteria. For data-pooling, fixed-effect model was applied if heterogeneity wasn't detected. Otherwise, random-effect model was adopted. Heterogeneity was detected by I squire (I2) test. All results of analysis were illustrated as forest plots. Publication bias was assessed using the Begg's adjusted rank correlation test. Standard mean difference (SMD) was calculated in continuous variables. Pooled hazard ratio or odds ratio was calculated in catergorical variables.Results: Seventeen clinical studies were finally included. Hepatic portal hemodynamic parameters were improved in statin users for a short-term response. For a long-term follow-up, statin treatment surprisingly decreased mortality rate (HR = 0.782, 95% CI: 0.718-0.846, I2 > 50%) and lower the occurrence of hepatocellular carcinoma (HR = 0.75, 95% CI: 0.64-0.86, I2 > 50%) in liver cirrhosis. Statin seemed not to decrease the risk of esophageal variceal bleeding and spontaneous bacterial peritonitis. However, statin was proved to decrease the risk of hepatic encephalopathy and ascites. Incidence of drug related adverse events didn't increase in statin users. Dose-dependent effects of statin on hepatocellular carcinoma development, decompensated cirrhosis events occurrence, and liver cirrhosis progression.Conclusion: Statin influenced parameters of hepatic portal vessel pressure in short-term treatment. Prognosis of liver cirrhosis benefited from statin treatment in long term follow-up. The efficacy and safety of statin in liver cirrhosis treatment is confirmed. To date, similar study is hardly seen before. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential microelement for humans and a beneficial element for plants. Increasing grain yield and Se content simultaneously in crop is of great significance. In the present study, we hypothesize that the delay in the application of appropriate concentrations of Se contributes to increased grain yield and Se content. A two-year field experiment was conducted to investigate the effects of three concentrations of selenite (0, 5, or 20 g ha−1) sprayed at two stages (initial or peak flowering stage) on the yield, yield components, agronomic traits, photosynthetic characteristics, dry matter, and Se accumulation and distribution of common buckwheat plants. Results indicated that low concentration of Se promoted leaf photosynthesis more than higher concentration. The grain dry matter weight and Se content increased linearly with increasing Se application concentration. Delayed growth stages resulted in 2.65 and 1.66 times higher grain Se content in plants sprayed with low and high Se concentrations, respectively. Both Se application rate and spray time contributed significantly to grain yield. The grain produced under low-concentration spraying of Se at the IFS was safe for human consumption. In the present study, we suggest that foliar application of Se at 5 g ha−1 at the IFS is the most efficient way to improve grain Se accumulation and yield in common buckwheat. Future research may focus on quantifying the species of Se and localizing the Se element distribution in grains. [Display omitted] • Low Se rate (5 g ha−1) promoted the growth and grain yield of common buckwheat. • The delay of spraying stage increased the Se content in common buckwheat grain. • The interaction of Se rates and spraying stage significantly affected grain yield. • Se content in common buckwheat grain correlated positively with Se application rates. [ABSTRACT FROM AUTHOR]

A multi-sensitization strategy is proposed to develop highly efficient and low efficiency roll-off solution-processed single-emission-layer all-fluorescence white organic light-emitting diodes, resulting in significantly boosted Förster energy transfer from blue emitter and green sensitizer to the orange-red dopant and thus a recorded external quantum efficiency of 22.8%. [Display omitted] • Multi-sensitization strategy to boost FRET and block exciton loss. • Exciton utilization efficiency was improved by BDP-C-Cz with HLCT character. • An EQE of 26.8% for blue s-OLED was achieved with 70% Θ// of spin-coated EML. • An EQE of 22.8% was achieved for the multi-sensitized all-fluorescence s-WOLED. Limited by the inefficient energy transfer from blue thermally activated delayed fluorescence (TADF) material to the complementary color fluorescent dopant and unwanted charge trapping effect, it is challenging to achieve a spectrally stable, high efficiency and low efficiency roll-off solution-processed single-emission-layer (SEL) white organic light-emitting diodes (WOLEDs). Herein, a highly efficient solution-processed all-fluorescence SEL-WOLED with suppressed efficiency roll-off and stable electroluminescence spectra is achieved by introducing a hybridized local and charge-transfer (HLCT) orange-red emitter (BDP-C-Cz) and a TADF sensitizer (4CziPN) into an optimized blue TADF OLED. Specially, the adopted BDP-C-Cz emitter has a high molar absorption coefficient, whose absorption spectrum has a significant overlap with the emission spectra of 4CziPN and blue emitter. By additionally introducing 4CziPN as an assistant sensitizer of blue emitter, Förster energy transfer can be enhanced to give favorable exciton allocation and thus effectively blocks triplet exciton loss. Accordingly, a recorded external quantum efficiency of 22.8% and current efficiency of 60.0 cd/A were realized for the solution-processed SEL-WOLEDs, with color coordinates of (0.33, 0.44) and good color stability, providing a valuable guidance for the future development of simplified, high-efficiency and low-cost WOLEDs. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A general molten salt route was applied to fabricate Zn 2 Ti 1− x Ge x O 4 (0 ≤ x ≤ 0.15) solid solutions. • The Zn 2 Ti 1− x Ge x O 4 (0 ≤ x ≤ 0.15) exhibit improved photocatalytic activity and durable photocatalytic stability. • The band gap of the Zn 2 Ti 0.9 Ge 0.1 O 4 solid solution is reduced and the light absorption is enhanced. • Zn 2 TiO 4 affords a light effective carrier mass and strong electron delocalization by forming a solid solution with Zn 2 GeO 4. Abstract Photocatalytic CO 2 reduction conjugated with H 2 O oxidation is regarded as a promising artificial photosynthesis system because it can simultaneously solve energy and environment problems. Here, a novel solid solution, Zn 2 Ti 1− x Ge x O 4 (0 ≤ x ≤ 0.15), with high photocatalytic activity for the reaction was successfully synthesized via a facile molten salts route. The Zn-based solid solutions with size about 200 nm have a homogeneous inverted cubic spinel structure (Fd3m) and a continuously modulated band gap with the Ge content. For the CO 2 reduction reaction with H 2 O under simulated solar irradiation, the Zn 2 Ti 1− x Ge x O 4 solid solutions display not only high activity for the conversion of CO 2 into CH 4 and CO fuels, but also long-term stability (>60 h of catalytic reaction). Experimental results and theoretical calculations indicated that the conduction and the valence bands of the cubic spinel Zn 2 TiO 4 are positively shifted by introducing Zn 2 GeO 4 with a pseudocubic inverse spinel structure, but the band gaps of solid solutions are simultaneously modulated with the introduction of germanium. Nevertheless, the Zn 2 TiO 4 affords a light-carrier effective mass and strong electron delocalization by forming a solid solution with Zn 2 GeO 4 , which is beneficial to improving migration of photogenerated electrons and holes. As a synergistic result of band gap narrowing and high carrier diffusion, good conversion efficiencies for production of solar fuels through the reactions of CO 2 reduction with H 2 O are achieved. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction (SCR) is now an established NOx removal technology for industrial flue gas as well as for diesel engine exhaust gas. However, it is still a big challenge to develop a novel low-temperature catalyst for NH3-SCR of NOx, especially at a temperature below 200°C. In the past few years, many studies have demonstrated the potential of iron (Fe)-based catalysts as low-temperature catalysts for NH3-SCR of NOx. Herein, we summarize the recent progress and performance of Fe-based catalysts for low-temperature NH3-SCR of NOx. Catalysts are divided into three categories: single FexOy, Fe-based multimetal oxide, and Fe-based multimetal oxide with support catalysts. The catalytic activity and selectivity of Fe-based catalysts are systematically analyzed and summarized in light of some key factors such as activation energy, specific surface area, morphology, crystallinity, preparation method and precursor, acid sites, calcination temperature, other metal dopant/substitute, and redox property of catalysts. In addition, H2O/SO2 tolerance and the NH3-SCR reaction mechanism over Fe-based catalysts, including Eley-Rideal and Langmuir-Hinshelwood mechanism, are emphasized. Lastly, the perspectives and future research directions of low-temperature NH3-SCR of NOx are also proposed. [ABSTRACT FROM AUTHOR]

Context:The flowers ofTrollius chinensisBunge (Ranunculaceae), used for respiratory tract infections, mainly contain flavonoids, phenolic acids, and alkaloids; however, the effective components are debatable because of their unclearin vivoactivities. Objective:This study investigates the effective components from the perspectives of biotransformation and absorption. Materials and methods:Both single person derived- and multiple people-derived intestinal florae were used to investigate the biotransformation of aqueous extract of the flowers ofT. chinensis(AEOF) at the concentrations of 15.0, 30.0, and 60.0 mg/mL, respectively, for 72 h. Both human colon adenocarcinoma cell line (Caco-2) monolayers and everted gut sacs were employed to evaluate the intestinal absorption of the intestinal bacterial transformed AEOF at the concentrations of 10, 20, and 30 mg/mL, respectively, for 180 min. Results:2″-O-β-l-Galactopyranosylorientin, orientin, vitexin, quercetin, veratric acid, proglobeflowery acid, and trolline in AEOF were not transformed by intestinal bacteria, while isoquercetin and trollioside were completely transformed. ThePappvalues of 2″-O-β-l-galactopyranosylorientin, orientin, and vitexin calculated based on the experimental data of intestinal absorption were at the levels of 10−5, whereas those of veratric acid, proglobeflowery acid, and trolline were at 10−4. The mass ratio of flavonoids to phenolic acids to alkaloids changed from 16:10:7 to 9:12:8 before and after absorption. Discussion and conclusion:The dominant position of flavonoids was replaced by phenolic acids after absorption. In addition to flavonoids which are usually considered as the dominant effective ones, phenolic acids and alkaloids should be also very important for the efficacy of these flowers. [ABSTRACT FROM PUBLISHER]

Aqueous foam is regarded as a versatile medium in numerous scientific and engineering applications due to its high viscosity and low density. The objective of this study is to investigate the flow characteristics of aqueous foams through the jet device and horizontal pipe. The pressure distribution and foam production capacity are measured at different operating conditions. Experimental results show that the pressure fluctuations reduce significantly by increasing the foam liquid concentration, especially in the downstream of jet device. The bubble flow turns into homogeneous foams gradually when the concentration increases from 0.025% to 0.35%, while the foam behaviors take little change at a higher concentration, and the foamability reaches a limit. Subjected to the large pressure difference produced between the top and bottom of horizontal pipe, aqueous foams undergo a gas–liquid separation at a high terminal pressure, resulting in bubbles at the top and liquid at the bottom. Therefore, the terminal pressure should be kept less than a critical value to hold a good foam pattern. Based on the above contributions, it is believed that the study laid an important foundation for the widespread application of foam technology. [ABSTRACT FROM PUBLISHER]

The performance enhancement of laser additive manufactured components depends on structural innovation and tailored printing, and the naturally optimized structures can provide inspiration for design and manufacturing. In this work, a layered TiB 2 /Ti6Al4V structure inspired by the biological structure of the Crysomallon squamiferum shell was designed and built by multi-material laser powder bed fusion (LPBF). The mechanisms for material densification, element diffusion, interfacial reaction, crystal growth and performance enhancement of multi-material LPBF-processed layered TiB 2 /Ti6Al4V parts were revealed by experiments and simulations. A strategy of process optimization by alternating appropriate printing parameters for metallic and ceramic materials yielded fully dense multi-material parts without discernible interfacial defects. The microstructure control showed that TiB whiskers were generated by the in-situ reaction between TiB 2 and Ti matrix, yielding a sound metallurgical bonding between dissimilar materials. The gradient elements and microstructures induced the gradually changed microhardness at the interface, thereby reducing the abrupt change and incoordination of microstructure and properties at the interface. The excellent flexural performance with a strength of 2033.2 MPa and a strain of 7.8% was obtained for the laser printed of TiB 2 /Ti6Al4V multi-material parts, revealing the contribution of the high interfacial bonding between layers to the performance enhancement. The internal crack propagation in laser-fabricated parts was fulfilled by crack deflection and multistage cracking, which extended the propagation path and increased the crack propagation energy. The flexural strength and ductility of LPBF-fabricated TiB 2 /Ti6Al4V multi-material parts were enhanced by the combined effects of the bio-inspired layered composite structure and the interior whiskers-structured reinforcement. This study sheds light on the manufacturing and strengthening of ceramic/metal multi-material using laser additive manufacturing technology. [Display omitted] • Fully dense layered ceramic/metal structure with good interfacial bonding was prepared by multi-material 3D printing. • Formation mechanisms of layered TiB 2 /Ti6Al4V multi-material parts were investigated by experiments and simulations. • Gradient distributions of elements, microstructures and microhardness at the interface were determined. • Mechanical properties were enhanced by the combined effects of bio-inspired layered composite and the whiskers-structured reinforcement. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multiple CT channels and 3LE states contribute to the speedy k r and RISC processes. • High Θ and small FWHM are realized due to the rigid disk-like structure. • η r and η out above 30% are achieved owing to triplet exciton utilization and high Θ. • EQE above 10% was realized for the standard blue device based on BO3N. The efficiency of pure blue Organic light-emitting diodes (OLEDs) still needs to be improved, which is limited by the utilization of the forbidden transition triplet excitons and low light-out-coupling efficiency in devices. Herein, two blue emitters were developed through combining multiple diphenylamine (DPA) donors with an oxygen-bridged boron (DBA) or triphenyl triazine (TRZ) acceptor. Notably, a narrow-band deep blue emission with a peak of 423 nm and a Full-width at half-maximum (FWHM) of 34 nm is realized for the boron-based emitter in toluene solution. Thanks to their multiple Charge transfer (CT) channels and high orientated disk-like structure, high radiative transition rates (k r > 108 s−1) and high horizontal emitting dipole ratios (Θ > 80%) can be realized simultaneously. Meanwhile, the introduction of the peripheral DPA units can also provide multiple localized triplet (3LE) states for spin up-conversion of forbidden transition triplet excitons. Owing to the effective up-conversion of triplet excitons and high light-out-coupling efficiency, maximum external quantum efficiency of more than 10% is achieved for the boron emitter-based pure blue OLEDs with a Commission Internationale de l'Eclairage (CIE) coordinates of (0.14, 0.08). [ABSTRACT FROM AUTHOR]

The non-doped organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) materials are attracting increasing attentions due to the excellent performance and simple fabrication. We report an effective design strategy of TADF emitters to improve the non-doped performance by adjusting the valence state of the S atom in TADF molecules and utilizing the steric hindrance effect. Two novel TADF materials PT-BZ-DMAC and PS-BZ-DMAC were designed and synthesized with benzophenone acceptor and acridine donor. In particular, the thioether or sulfone group was attached to benzophenone. Remarkably, the bluish-green TADF-OLED with non-doped PT-BZ-DMAC turned on at 2.5 V and realized a maximum external quantum efficiency (EQE) of 17.34%, which was comparable with its doped OLED (17.71%) but showed much slower roll-off. At 100 and 1000 cd m−2, the non-doped PT-BZ-DMAC device still maintained acceptable efficiencies at 14.65% and 12.59%. In contrast, sulfone-modified PS-BZ-DMAC exhibited good efficiency of 20.55% only in doped OLED. The single crystal analysis and DFT calculation revealed that the phenyl thioether unit in PT-BZ-DMAC hardly contributes to the LUMO or the electronic transitions, instead determines the highly twisted geometry and acts as the barrier group, finally improving the performance of PT-BZ-DMAC in neat film device. Two TADF emitters are developed by attaching thioether or sulfone groups to the benzophenone acceptor. Unlike the strong electron withdrawing sulfone group that contributes to the electronic transition and TADF, the phenyl thioether blocked the conjugation of molecular backbone. The steric hindrance effect of phenyl thioether moiety along with the intermolecular hydrogen bondings can effectively prevents exciton quenching, thus further raising the EQE of non-doped TADF-OLED to 17.34% with low efficiency roll-off. [Display omitted] • Thioether and sulfone were incorporated as substituents to design TADF molecules PT-BZ-DMAC and PS-BZ-DMAC. • Thioether was found to strongly suppress intermolecular interactions and prevent exciton quenching via steric hindrance effect. • Non-doped OLED of thioether based PT-BZ-DMAC exhibited comparably high efficiency (17.34%) to its doped device (17.71%), but with much slower roll-off. • Sulfone based PS-BZ-DMAC exhibited high efficiency of 20.55% only in doped OLED, while non-doped device did not work. [ABSTRACT FROM AUTHOR]

It is generally difficult to identify fluid types in low-porosity and low-permeability reservoirs, and the Chang 8 Member in the Ordos Basin is a typical example. In the Chang 8 Member of Yanchang Formation in the Zhenyuan area of Ordos Basin, affected by lithology and physical properties, the resistivity of the oil layer and water layer are close, which brings great difficulties to fluid type identification. In this paper, we first analyzed the geological and petrophysical characteristics of the study area, and found that high clay content is one of the reasons for the low-resistivity oil pay layer. Then, the formation water types and characteristics of formation water salinity were studied. The water type was mainly CaCl2, and formation water salinity had a great difference in the study area ranging from 7510 ppm to 72,590 ppm, which is the main cause of the low-resistivity oil pay layer. According to the reservoir fluid logging response characteristics, the water saturation boundary of the oil layer, oil–water layer and water layer were determined to be 30%, 65% and 80%, respectively. We modified the traditional resistivity–porosity cross plot method based on Archie's equations, and established three basic plates with variable formation water salinity, respectively. The above method was used to identify the fluid types of the reservoirs, and the application results indicate that the modified method agrees well with the perforation test data, which can effectively improve the accuracy of fluid identification. The accuracy of the plate is 88.1%. The findings of this study can help for a better understanding of fluid identification and formation evaluation. [ABSTRACT FROM AUTHOR]

Saturated red iridium phosphors are strongly desired for application in organic light-emitting diodes (OLEDs). Most of the reported iridium complexes with 2-arylquinoline or its derivatives as cyclometalating ligands are orange-red phosphorescent with peak wavelength below 620 nm. Herein trifluoromethyl (CF 3) or Fluorine (F) is introduced into the 6-site of quinoline ring to design and synthesize the cyclometalated ligands 2-phenyl-6-CF 3 /F-quinoline (CF 3 -phq or F-phq) and heteroleptic iridium complexes Ir(CF 3 -phq) 2 (acac) (Ir-1), Ir(CF 3 -phq) 2 (tmd) (Ir-2), Ir(F-phq) 2 (acac) (Ir-3) and Ir(F-phq) 2 (tmd) (Ir-4). Owing to the electron-deficient feature of CF 3 and F, the electron affinity of these complexes are increased, the corresponding LUMOs are pulled downwards, and the phosphorescence of CF 3 -containing iridium complexes are saturated red with peaks at 627–632 nm in photoluminescence. At the same time, by varying the ancillary ligand from acetylacetonate (acac) to 2,2,6,6-tetrametylheptane-3,5-dionate (tmd), the emitting performance are dramatically improved. As a result, the Ir(CF 3 -phq) 2 (tmd) based red OLED realized pure red electroluminescence with Commision Internationale de L'Eclairage (CIE) coordinates of (0.67, 0.33) with a high brightness of 12695 cd m−2 and a maximum external quantum efficiency of 14.96%, respectively, which maintained as high as 9.62% at a practical luminance of 1000 cd m−2. This is the first example of saturated red iridium phosphors with structure modification at the 6-site of quinoline ring of 2-phenylquinoline ligand. By incorporating electron-withdrawing fluorine (-F) or trifluoromethyl (-CF 3) at the 6-site of quinoline ring of the 2-phenyl-quiniline cyclometalating ligands and changing the auxiliary ligand from acac to bulky tmd, the heteroleptic iridium complexes realize pure red phosphorescence with CIE coordinates of (0.67, 0.33) and high efficiency of 14.96% in doped organic light-emitting diodes, which still remains at 9.62% at a practical brightness of 1000 cd m−2. Image 1 [ABSTRACT FROM AUTHOR]

In order to develop the high efficiency and cost-effective particle removal technology, a novel particle removal unit combined flue gas condensation and acoustic agglomeration was designed based on theoretical analysis. The performance of the designed combined particle removal unit was evaluated by the laboratory scale experiments. Compared with the single external field of sound or condensation, the combination of the two external fields made the removal efficiency higher. The maximum total removal efficiency could be up to 70% when the sound frequency was 1500 Hz, the sound pressure level (SPL) was 141 dB, and the cooling water flow rate was 560 L/h. With the increase of flue gas temperature drop, the removal efficiency increased. In addition, more waste water and heat could be recovered from the flue gas. There was an optimal sound frequency range of 1500–2000 Hz for the combined particle removal unit, and the removal efficiency decreased whether the sound frequency increased or decreased. The removal efficiency increased with the rise of SPL, but the considerable improvement was obtained only when the SPL exceeded 120 dB. Therefore, there was an SPL threshold for the application of combined particle removal unit. Through the techno-economic comparisons with other technologies, the novel particle removal unit was proved to be a highly efficient and cost-effective particle removal technology. • A novel combined particle removal unit was designed based on theoretical analysis. • The performance was evaluated by laboratory scale experiments. • Effects of parameters on particle removal efficiency were analyzed. • An optimal sound frequency range for particle removal was determined. • There was a SPL threshold for the application of combined particle removal unit. [ABSTRACT FROM AUTHOR]

This approach is developed to achieving smaller bandgap values and a closer bracketing of the CO 2 /reduced-H 2 O/oxidized redox couples to drive the overall conversion reactions of CO 2 and H 2 O, and this is critical for efficient solar energy conversion. Highlights • A new type of spinel germanium and iron double-substituted ZnGa 2 O 4 solid-solution photocatalysts was prepared. • The solid-solution catalysts showed improved photocatalytic activities for CO 2 reduction with H 2 O. • Introducing ZnFe 2 O 4 and Zn 2 GeO 4 into ZnGa 2 O 4 can effectively expand the light-harvesting wavelength range. • A great difference in the mobility between the electrons and holes to lessen the electron–hole recombination rate. • This approach can achieve smaller bandgap values and a closer bracketing of the CO 2 /reduced-H 2 O/oxidized redox couples. The conversion of CO 2 into renewable fuels by artificial photosynthesis is an attractive solution for storing solar energy in the form of chemical fuel. Herein, we presented a general molten-salt route to synthesize spinel germanium and iron double-substituted ZnGa 2 O 4 solid solutions. Introducing ZnFe 2 O 4 and Zn 2 GeO 4 into ZnGa 2 O 4 can effectively expand the light-harvesting wavelength range to improve the ability of photocatalyst in CO 2 reduction and H 2 O oxidation. The solid solutions provide a larger effective mass of holes compared with electrons through the introduction of Fe3d, Ge4s and Ge4p orbitals according to DFT analysis. This leads to a great difference in the mobility between the electrons and holes to lessen the electron–hole recombination rate, and enhance the conversion of CO 2 and H 2 O in kinetics. This approach is developed to achieving smaller bandgap values and a closer bracketing of the CO 2 /reduced-H 2 O/oxidized redox couples to drive the overall conversion of CO 2 and H 2 O. [ABSTRACT FROM AUTHOR]

It is well-known that there is an interaction between biomass and coal in co-gasification process. In this paper, gasification of semi-coke (SC) and soybean straw char (SS) and their blends were carried out using non-isothermal thermogravimetric method. Interaction between SS and SC during co-gasification was investigated and synergy factors were calculated at different conversion stage. In order to explore whether the physical and chemical structure features have an effect on interaction, surface area analyzer, XRF and Raman spectrometer were adopted to determine the porous properties, ordering degree and ash composition for blends. The results show that the changes of porous properties and ordering degree for blends follow a linear law. The correlation expressions linking char characteristics to char reactivities indicate that the degree of graphitization is the main reason influencing the gasification reactivity. The interaction exhibits a negative synergetic effect at low conversion stage and a positive synergetic effect at high conversion stage. In addition, there are significant synergistic effects in the co-gasification of 75%SC/25%SS. Similar conclusions about synergetic effect are also observed from the kinetics data calculated by three kinetic models. • The biochar reactivities significantly greater than that of semi-coke. • The reactivities of biochar and semi-coke correlate well with their properties. • The increasing proportion of biochar weakens synergies during co-gasification. • Synergies on gasification of char vary with biochar/semi-coke mass ratio. • SF < 1 at low conversion stage and SF ＞1 at high conversion stage for co-gasification. [ABSTRACT FROM AUTHOR]