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The reported metal–organic framework (MOF) catalyst realizes CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO2, thus achieving quantitative (>99 %) methanol yield. Density‐functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. CO2 fixation: A metal–organic framework (MOF) containing metal‐free N‐heterocyclic carbene moieties performs quantitative hydrogen transfer from silanes to CO2 to obtain CH3OH under ambient conditions. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. [ABSTRACT FROM AUTHOR]

An orange-yellow emitting cationic iridium(III) complex [(ptpy)Ir(BCP)]PF (ptpy: 2-(p-tolyl)pyridine; BCP: bathocuproine) was synthesized. [(ptpy)Ir(BCP)]PF exhibited high thermal stability with the thermal decomposition temperature ( T ) of 375 °C, with the temperature increasing from 20 to 100 °C, the photoluminescent intensity of [(ptpy)Ir(BCP)]PF decreased to 79.9%. It can be efficiently excited by blue light (λ = 457 nm) of GaN chip, and a series of GaN-based light-emitting diodes (LEDs) were fabricated by using it as phosphors blended in silicone at different blending concentrations. At 1.0 wt.%, a cold white LED was obtained, the corresponding color rendering index (CRI) was 77.1, correlated color temperature (CCT) was 6278 K, luminous efficiency ( η ) was 68.4 lm W, and Commission Internationale de L'Eclairage (CIE) value was (0.32, 0.25). At 2.0 wt.%, a neutral white LED was obtained, the corresponding CRI was 74.2, CCT was 4737 K, η was 75.4 lm W, and CIE value was (0.34, 0.27). At 2.5, 3.0, 4.0 and 5.0 wt.%, four warm white LEDs were obtained, among them, the maximum η was 85.8 lm W (at 4.0 wt.%), the maximum CRI was 73.7 (at 2.5 wt.%), their CCT changed between 3410 K and 2328 K, the CIE values were (0.37, 0.30), (0.41, 0.34), (0.46, 0.39) and (0.49, 0.41) respectively. The results suggest [(ptpy)Ir(BCP)]PF is a promising phosphor candidate for white LEDs, especially for warm white LEDs. [ABSTRACT FROM AUTHOR]

• Experiments of droplets impacting onto tubular surfaces are conducted. • Effects of wettability and curvature ratio are studied. • Dislocation-selective chemical etching and surface modification are used to change the surface wettability. • Increase of the curvature ratio hinders rebound but promotes break-up. • Lower surface wettability inhibits spreading, but promotes retraction and rebound. Surface wettability plays a significant role on the dynamic characteristics of droplet impact. In this paper, five different wettability surfaces are prepared for experiments by dislocation-selective chemical etching and surface modification, three of which are mainly discussed. The corresponding apparent contact angles are 13°, 107°, and 153°, respectively. The dynamic processes of droplets impacting the hydrophilic, hydrophobic and super-hydrophobic tubular surfaces with the impact velocity of 0.94 m/s are observed by high speed photography. The effect of surface wettability on droplet impact is analysed with the curvature ratios of 1.4, 0.43, and 0.26, respectively. It is found that the increase of the curvature ratio hinders rebound but promotes the break-up of the droplet. When the curvature ratio is a constant, poor surface wettability hinders droplet spreading, but promotes retracting and rebounding; An interesting phenomenon is found that, when the contact angle is a constant, the maximum spreading factor increases firstly and then decreases with the increase in the curvature ratio, i.e., there is a critical curvature ratio for each contact angle. [ABSTRACT FROM AUTHOR]

A novel noise model is proposed for a balanced-detection ultrafast imaging system to comprehensively analyze the noise in the system. The whole noise model is obtained by solving for erbium-doped fiber amplifier (EDFA) noise, intersymbol interference (ISI) noise and low-pass filter (LPF) noise successively with stochastic process theory. Then, the nonmonotonic relationship between the cut-off frequency and the signal-to-noise ratio (SNR) for certain experimental parameters are derived quantitatively and qualitatively: the SNR first increases and then decreases when the cut-off frequency increases, while the unique extreme point is located at 6.3 GHz. In addition, imaging results are obtained accordingly. The model and the results can provide a reference for system design and parameter selection. [ABSTRACT FROM AUTHOR]

The effect of cerium content (0, 0.011, 0.017, 0.075 wt%) on non-metallic inclusions and solidification microstructures of 55SiCr high-strength spring steel was experimentally studied, along with thermodynamic calculations. The results show that Ce addition changes the type and size of inclusions in this steel and influences the characteristics of the solidification microstructure. In the sample without Ce addition, the main inclusions are MnS, SiO2, SiO2–MnS, and CaO–SiO2–MgO, and the equiaxed ratio in the solidification structure is 44.63%. However, when Ce content increases to 0.011 wt%, the inclusions in the steel become mainly Ce–S, Ce–O–S, and a small amount of MnS, and the equiaxed ratio increases to 50.42%. As the Ce content increases to 0.017 wt%, the inclusions are predominantly Ce–S, Ce–O–S, and Ce–O–S–Ca, while some Ce–P and Ce–O–P–C inclusions are also observed. The equiaxed ratio increases to 67.63%, showing the best effect on heterogeneous nucleation during solidification. When Ce content in the steel reaches 0.075 wt%, the Ce-containing inclusions are Ce–S, Ce–O, Ce–P, Ce–P–O, and Ce–O–S–As, and the size becomes larger. The formation mechanism of inclusions is explained by Gibbs free energy calculations and thermodynamic diagrams. [ABSTRACT FROM AUTHOR]

To study the flame propagating characteristic and its coupling effect with other parameters in the LPG pipeline, a typical pipeline model with two equal‐length branches perpendicular to each other is designed for experiment and simulation. Then, gas explosion scenarios are experimentally tested and numerically simulated, which is followed by the analysis of flame shape changing with time and peak temperature changing with space. Results show that when passing through the bifurcation, flame propagates to vertical branch B in a sharp knife shape affected by the strong vortex, reflected airflow, and compressed pressure wave in the pipeline with a diameter of 0.125 m. At the monitoring point that is 0.4 m away from the bifurcation point, the peak temperature of the vertical branch B is 57.87% bigger than that of the horizontal branch C, and its arrival time is 80% longer than that of the horizontal branch C, due to the existence of flame in vertical branch B. What's more, in both branches, the coupling results between peak temperature and peak velocity agree very well with the growth function, while the coupling results between peak temperature and peak pressure agree well with the decay function, providing aids to the optimal layout design of industrial pipeline branches as well as to the explosion suppression measures. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-image encryption method based on ghost imaging of Hadamard basis patterns and spatial multiplexing. In the encryption process, firstly, the pixels of each original image are rearranged in ascending order, and then each image rearranged is transformed by Fourier transformation. Most of the spectral information of the images after Fourier transformation is concentrated in the central part, which is sampled by spectrum clipping. Multiple sampled images are combined into one image by spatial multiplexing technology after inverse operation of Fourier transformation is performed. Finally, the combined image is encrypted by ghost imaging using Hadamard basis patterns to obtain ciphertext. In the decryption process, the original plaintext images are reconstructed by compressive sensing algorithm using Hadamard basis patterns and the position index matrices of each original image. We prove the safety and robustness of the proposed method through numerical simulation analysis. Theoretical analysis and numerical simulation analysis prove the safety and robustness of the proposed method. [ABSTRACT FROM AUTHOR]

Ultrafast time‐stretch imaging technique recently attracts an increasing interest for applications in cell classification due to high throughput and high sensitivity. A novel imaging modality of time‐stretch imaging technique for edge detection is proposed. Edge detection based on the directional derivative is realized using differential detection. As the image processing is mainly implemented in the physical layer, the computation complexity of edge extraction is significantly reduced. An imaging system for edge detection with the scan rate of 77.76 MHz is experimentally demonstrated. Resolution target is first measured to verify the feasibility of the edge extraction. Furthermore, various cells, including red blood cells, lung cancer cells and breast cancer cells, are detected. The edges of cancerous cells present in a completely different form. The imaging system for edge detection would be a good candidate for high‐throughput cell classification. An ultrafast time‐stretch imaging technique for edge detection is demonstrated at the scan rate of 77.76 MHz for extracting the edges of various cells including red blood cells, lung cancer cells and breast cancer cells. As the edge detection is implemented in the physical layer, the computation complexity in the back‐end digital signal processing could be significantly reduced. The cells can be easily and rapidly identified by distinguishing the edges. [ABSTRACT FROM AUTHOR]

It is well established that the ship-ice interaction process is quite complex and associated ice loads on the icebreaker hull is a stochastic process. Obviously, novel accurate statistical methods and models should be developed and applied to estimate extreme bow stresses. This paper studies icebreaker bow stresses based on measured distribution of ice thickness in the Arctic Ocean on the way to and from the North Pole. Since the vessel route was carefully selected searching for easier ice conditions, the Arctic Ocean crossing was not a straight linear but a meandering path. Thus, the specific ship route data was biased with respect to general ice statistics in the region, but true with respect to the route specific ice data encountered by a ship navigating in that region. Therefore the route specific ice thickness data is directly needed for ship design and navigation analysis. It is assumed that captains are competent and knowledgeable, and therefore will select a route that provides the most favourable ice conditions. This paper contributes to study of the newest Chinese self-designed polar icebreaker, serving the purpose of enhancing icebreaker operational reliability. Finite Element Method software package ANSYS/LS-DYNA has been employed to simulate bow stress pattern for a particular icebreaker operating in the Arctic Ocean. Extreme bow stresses were estimated using Naess-Gaidai method. The latter is a first application of Naess-Gaidai method to a distribution with lower bound. Thus this paper aims at introducing an efficient method of estimating route-specific icebreaker extreme bow stresses. [ABSTRACT FROM AUTHOR]

Two new optimized three-derivative Runge–Kutta type methods with vanishing phase-lag and its first derivative for the numerical integration of Schrödinger equation are derived in this paper. We present the error analysis in terms of the asymptotic expressions of the local errors. Numerical results are reported to show the efficiency and robustness of the new methods for the numerical integration of the Schrödinger equation with the Woods–Saxon potential. [ABSTRACT FROM AUTHOR]

Long-term exposure to high concentrations of fine particles can cause irreversible damage to people's health. Therefore, it is of extreme significance to conduct large-scale continuous spatial fine particulate matter (PM2.5) concentration prediction for air pollution prevention and control in China. The distribution of PM2.5 ground monitoring stations in China is uneven with a larger number of stations in southeastern China, while the number of ground monitoring sites is also insufficient for air quality control. Remote sensing technology can obtain information quickly and macroscopically. Therefore, it is possible to predict PM2.5 concentration based on multi-source remote sensing data. Our study took China as the research area, using the Pearson correlation coefficient and GeoDetector to select auxiliary variables. In addition, a long short-term memory neural network and random forest regression model were established for PM2.5 concentration estimation. We finally selected the random forest regression model (R2 = 0.93, RMSE = 4.59 μg m−3) as our prediction model by the model evaluation index. The PM2.5 concentration distribution across China in 2021 was estimated, and then the influence factors of high-value regions were explored. It is clear that PM2.5 concentration is not only related to the local geographical and meteorological conditions, but also closely related to economic and social development. [ABSTRACT FROM AUTHOR]

Slag eyes are the upper exposed areas of molten steel in a refining ladle that are formed due to excessive bottom argon bubbling. This phenomenon frequently occurs in the steel-refining process and can lead to slag entrapment and re-oxidation of molten steel. Taking a 150-t industrial steel ladle as the research object, the effects of a dual-plug gas-blown process on the slag-eye size were studied using hydraulic modeling and large-eddy simulations. The experimental results showed that at higher gas flow rates such as 9.1 and 11.7 normal liters/min (Nl/min), the relative central angle of the two porous plugs had a significant effect on the slag-eye size; conversely, at lower gas flow rates, its influence could be ignored. Due to the tendency of the two small slag eyes to merge, the 0.6R–45° (R being the bottom radius of the ladle) case resulted in a larger total slag-eye area compared to the cases with other angles. The 0.6R–135° case showed the most beneficial results for reducing the slag-eye size. Additionally, the numerical simulations helped us to visualize the bubble-uplifting and slag-eye formation processes, and they allowed an exploration of the slag-entrapment mechanism. The simulation results showed that the symmetric gas-blown mode can reduce slag entrapment when compared with the asymmetric mode for the 135°–11.7 Nl/min case; this will be favorable to control the cleanliness of the molten steel. Additionally, analysis of both liquid-level fluctuations and turbulent-kinetic-energy distributions further confirmed the advantages of the symmetric gas-blown mode for suppressing slag entrapment. [ABSTRACT FROM AUTHOR]

Grassland desertification stands as an ecological concern globally. It is crucial for desertification prevention and control to comprehend the variation in area and severity of desertified grassland (DGL), clarify the intensities of conversion among DGLs of different desertification levels, and explore the spatial and temporal driving factors of desertification. In this study, a Desertification Difference Index (DDI) model was constructed based on albedo-EVI to extract desertification information. Subsequently, intensity analysis, the Geo-detector model, and correlation analysis were applied to analyze the dynamics and driving factors of desertification. The results showed the following: (1) Spatially, the DGL in Xilingol exhibited a zonal distribution. Temporally, the degree of DGL decreased, with the proportion of severely and moderately desertified areas decreasing from 51.77% in 2000 to 37.23% in 2020, while the proportion of nondesertified and healthy areas increased from 17.85% in 2000 to 37.40% in 2020; (2) Transition intensities among different desertification levels were more intense during 2000–2012, stabilizing during 2012–2020; (3) Meteorological factors and soil conditions primarily drive the spatial distribution of DDI, with evapotranspiration exhibiting the most significant influence (q-value of 0.83), while human activities dominate interannual DDI variations. This study provides insights into the conversion patterns among different desertification levels and the divergent driving forces shaping desertification in both spatial and temporal dimensions in Xilingol. [ABSTRACT FROM AUTHOR]

Background: At present, the process of inspection and quarantine starts with sampling at the customs port, continues with transporting the samples to the central laboratory for inspection experiments, and ends with the inspected results being fed back to the port. This process had the risks of degradation of biological samples and generation of pathogenic microorganisms and did not meet the rapid on-site detection demand because it took a rather long time. Therefore, it is urgently needed to develop a rapid and high-throughput detection assay of pathogenic microorganisms at the customs port. The aim of this study was to develop a microfluidic chip to rapidly detect swine pathogenic microorganisms with high-throughput and higher accuracy. Moreover, this chip will decrease the risk of spreading infection during transportation. Results: A series of experiments were performed to establish a microfluidic chip. The resulting data showed that the positive nucleic acid of four swine viruses were detected by using a portable and rapid microfluidic PCR system, which could achieve a on-site real-time quantitative PCR detection. Furthermore, the detection results of eight clinical samples were obtained within an hour. The lowest concentration that amplified of this microfluidic PCR detection system was as low as 1 copies/μL. The results showed that the high specificity of this chip system in disease detection played an important role in customs inspection and quarantine during customs clearance. Conclusion: The microfluidic PCR detection system established in this study could meet the requirement for rapid detection of samples at the customs port. This chip could avoid the risky process of transporting the samples from the sampling site to the testing lab, and drastically reduce the inspection cycle. Moreover, it would enable parallel inspections on one chip, which greatly raised the efficiency of inspection. [ABSTRACT FROM AUTHOR]

• Ten factors were chosen for assessing the risk of vegetation change. • The random forest model was employed to invert above-ground biomass. • The Mann-Kendall method was utilized to compute above-ground biomass trends, indicating vegetation degradation. • Bayesian Network enhanced the reliability and efficiency of vegetation change risk assessment. • The spatial and temporal distribution and trend of vegetation change risk in Xilin Gol League were analyzed. As an essential ecological barrier in the north of China, the grassland degradation situation in the Xilin Gol League of Inner Mongolia has remained severe in recent years. Based on data spanning from 2010 to 2022, this study utilizes a set of ten indicators, encompassing altitude, temperature, precipitation, wind speed, FVC, LAI, FRAR, NPP, ET, and above-ground biomass, to construct a Bayesian model for assessing ecological risks associated with vegetation change in the Xilin Gol League. In the case of the most crucial parameter, above-ground biomass, we integrate spectral bands, vegetation indices, and ground-truth data, employing the Random Forest algorithm to estimate the above-ground biomass in the Xilin Gol League. The study further applies the Mann-Kendall trend test and Sen's slope estimation to analyze changes in this parameter and employs it as an indicator for assessing grassland degradation. The results showed that (1) Overall, the risk level decreases gradually from the west to the east and aligns with the grassland types of the Xilin Gol League. (2) In terms of spatial and temporal distribution, medium and high-risk areas are primarily located in the western region of the Xilin Gol League, showing a distinct westward shift from 2010 to 2022. (3) Areas with higher grassland degradation risk are characterized by lower altitudes, higher temperatures, less precipitation, lower vegetation coverage, and reduced potential evapotranspiration. (4) Under the pressures of both climate warming and vegetation change, there has been a significant shift in grassland degradation risk levels in the Xilin Gol League. The application of the Bayesian model effectively reveals intricate causal relationships among various variables, such as climate, terrain, and vegetation dynamics. This study could provide guidance for the prevention and control of grassland degradation in the Xilin Gol League. [ABSTRACT FROM AUTHOR]

The reported metal–organic framework (MOF) catalyst realizes CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO2, thus achieving quantitative (>99 %) methanol yield. Density‐functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. [ABSTRACT FROM AUTHOR]

The reported metal–organic framework (MOF) catalyst realizes CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO2, thus achieving quantitative (>99 %) methanol yield. Density‐functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. CO2 fixation: A metal–organic framework (MOF) containing metal‐free N‐heterocyclic carbene moieties performs quantitative hydrogen transfer from silanes to CO2 to obtain CH3OH under ambient conditions. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. [ABSTRACT FROM AUTHOR]

The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of organophosphorus pesticides and antibiotics, a novel Cd(II) chain-based zwitterionic metal-organic framework MOF 1 with high sensitivity fluorescence sensing performance was successfully synthesized. A series of researches showed that the water- and pH-stable bifunctional MOF 1 has a great ability to detect phosmet (PSM) and chlortetracycline (CTC) in water through fluorescence quenching effect, with high detection sensitivity, low detection limits (0.0124 μM and 0.0131 μM), short response time (40 s) and reusability. Practical application results revealed that MOF 1 could detect PSM and CTC in milk, beef, chicken and egg samples, with satisfactory recoveries (95.2%–103.7%). As a novel fluorescence probe, MOF 1 , is known the first case that can detect PSM in animal-derived samples, and the first dual-function material capable of detecting PSM and CTC. Mechanism studies displayed that competitive absorption and photoinduced electron transfer clearly authenticate the high quenching performance of the material. The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of organophosphorus pesticides and antibiotics, a novel Cd(II) chain-based zwitterionic metal-organic framework [CdL] (MOF 1) with high sensitivity fluorescence sensing performance was successfully synthesized. X-ray single crystal diffraction, IR, elemental analyses, SEM, EDS elemental mapping, and Hirshfeld surface analysis have been used to characterize its structure and morphology. A series of property researches showed that the water- and pH-stable bifunctional MOF 1 has a great ability to detect phosmet (PSM) and chlortetracycline (CTC) in water through fluorescence quenching effect, with high detection sensitivity, low detection limits (0.0124 μM and 0.0131 μM), short response time (40 s) and reusability. Practical application results revealed that MOF 1 could detect PSM and CTC in milk, beef, chicken and egg samples, with satisfactory recoveries (95.2%–103.7%). As a novel fluorescence probe, MOF 1 , is known the first case that can detect PSM in animal-derived samples, and the first dual-function material capable of detecting PSM and CTC. Mechanism studies displayed that competitive absorption and photoinduced electron transfer clearly authenticate the high quenching performance of the material. [Display omitted] • A water and pH stable luminescent Cd(II) chain-based metal-organic framework were prepared by one-step hydrothermal method. • The sensor could detect phosmet and chlortetracycline in aqueous solution with high sensitivity. • The first luminescent sensing material for the detection of phosmet and chlortetracycline in actual food samples. [ABSTRACT FROM AUTHOR]

A novel red-emitting cationic iridium(III) coordination polymer using 2-(9-(2-ethylhexyl)-9 H -carbazol-3-yl)benzo[ d ]thiazole as main ligands, 4,4′-bipyridine as bridging auxiliary ligands and Cl ˉ as anions was synthesized. It had high thermal stability with a thermal decomposition temperature ( T d ) of 345 °C and low thermal quenching with an activation energy ( E a ) of 0.2760 eV, with the temperature increasing from 20 °C to 100 °C, its photoluminescent intensity decreased to 76.7%. It can be efficiently excited by blue light of GaN chips, the cold white light of GaN-based LEDs using only Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce, 7.0 wt% in silicone) as phosphors can become warmer when it was blended in. When blending concentrations were 0.1 wt% and 0.2 wt%, the cold white light became neutral white light, the correlated color temperature (CCT) decreased from 6157 K to 5240 K, then to 4043 K, the color rendering index (CRI) changed from 72.7 to 81.3, then to 78.6, the luminous efficiency ( η L ) changed from 134.1 lm·w −1 to 61.9 lm·w −1 , then to 46.3 lm·w −1 , the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates changed from (0.32, 0.33) to (0.34, 0.33), then to (0.38, 0.36). At 0.3 wt%, the light became warm white light, the corresponding CCT was 3475 K, CRI was 75.6, η L was 36.9 lm·w −1 , and CIE value was (0.41, 0.40). The results suggest the coordination polymer is a promising red-emitting phosphor candidate for neutral and warm white LEDs, especially for warm white LEDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel cationic iridium(III) complex containing a Hg2+-sensitive thiosemicarbazide unit was synthesized. • Used as a "turn-on" chemodosimeter for luminescent detection of Hg2+ in DMF/PBS buffer solution at pH = 7–11. • The detection limit was 1.83 × 10−9 mol∙L−1 (0.37 ppb). A novel cationic iridium(III) complex [(ppy) 2 Ir(bPCPC)]PF 6 (ppy: 2-phenylpyridine; bPCPC: 2-([2,2′-bipyridine]-4-carbonyl)-N-phenylhydrazinecarbothioamide) containing a thiosemicarbazide unit was designed and synthesized. The thiosemicarbazide unit was a sensitive functional group to Hg2+, when it reacted with Hg2+, it was desulphurized and thus led to the formation of 1,3,4-oxadiazole, [(ppy) 2 Ir(bPCPC)]PF 6 resultantly was used as a "turn-on" chemodosimeter for luminescent detection of Hg2+ in DMF/PBS buffer solution at pH = 7–11. Except for Ag+, recognition capability of [(ppy) 2 Ir(bPCPC)]PF 6 to Hg2+ was not interfered by other common metal ions (Co2+, Li+, Zn2+, Pb2+, K+, Al3+, Na+, Mn2+, Cu2+, Fe2+, Fe3+, Cr3+, Ba2+, Mg2+, Ni2+ and Ca2+). The detection limit was 1.83 × 10−9 mol∙L−1 (0.37 ppb), which indicated the complex was a highly sensitive chemiluminescent detection reagent of Hg2+. [ABSTRACT FROM AUTHOR]

A series of naphthyl-modified graphitic carbon nitride were prepared by using melamine, cyanuric acid as precursors and 6-(naphthalen-2-yl)-1,3,5-triazine-2,4-diamine as a molecular dopant. When their mass ratio was 20:20:1, the product (g–C 3 N 4 –Naphth 20:20:1) showed the best photoluminescence performances. The emission spectrum of g–C 3 N 4 –Naphth 20:20:1 was mainly at 410–650 nm and much wider than that of bulk g-C 3 N 4 (mainly at 410–550 nm), relative to bulk g-C 3 N 4 , the maximum emission wavelength (λ em,max) changed from 455 nm to 485 nm, the light color correspondingly changed from deep blue to blue-green, the PL efficiency increased from 5.1% to 11.3%. Excited by ultraviolet chips (λ em,max = 365 nm), a series of LEDs using g–C 3 N 4 –Naphth 20:20:1 blended in epoxy resin at 4.0 wt% together with red-emitting SrAlSiN 3 :Eu2+ at x wt-% (x = 0.08, 0.12, 0.16, and 0.20) as phosphors were fabricated. When x = 0.08, 0.12, 0.16, the LEDs emitted neutral white light, their correlate color temperatures (CCT) were 5277 K, 4602 K and 3794 K, color rendering indexes (CRI) were 85.4, 88.1 and 79.7, respectively. When x = 0.20, it was a warm white LED, its CCT was 3312 K and CRI was 83.3. The results suggested the naphthyl-modified g-C 3 N 4 can be used as efficient metal-free phosphors for LEDs. Blue-green-emitting naphthyl-modified graphitic carbon nitride (g–C 3 N 4 –Naphth) were prepared and used as phosphors in white LEDs. [Display omitted] • A series of naphthyl-modified g-C 3 N 4 were prepared. • The luminescent color changed from deep blue to blue-green after naphthyl modification. • The PL efficiency changed from 5.1% to 11.3% after naphthyl modification. • The naphthyl-modified g-C 3 N 4 was successfully used as phosphors in white LEDs. [ABSTRACT FROM AUTHOR]

A sp2-carbon-linked covalent organic framework (COF) containing tetraphenylethene units was successfully synthesized by using 2,2'-(1,4-phenylene)diacetonitrile and 4′,4‴,4‴'',4‴''''-(Ethene-1,1,2,2-tetrayl)tetrakis(([1,1′-biphenyl]-4-carbaldehyde)) as monomers. After being investigated by powder X-Ray diffraction (PXRD), nitrogen adsorption-desorption and theoretical calculations, the dual-pore eclipsed Kagome structure (AA-K) of the COF was confirmed. The COF emitted bright yellow light with a solid-state photoluminesce quantum yield (PLQY) of 39.2%. It exhibited high thermal stability with a thermal decomposition temperature (T d) of ca. 610 °C, and its relative emission intensity at 90 °C was nearly 80.0% of that at 30 °C. The COF was blended in epoxy resin at different concentrations and used as phosphors, excited by GaN-based blue-emitting chips (λ em,max ≈ 455 nm), a series of white light-emitting diodes (WLEDs) with different correlated color temperature (CCT) can be obtained. At 1.5 wt%, a cold WLED was obtained, its CCT was 6125 K, color rendering index (CRI) was 83.4, Commission Internationale de L'Eclairage (CIE) chromaticity coordinate was (0.32, 0.29), luminous efficiency (η L) was 20.31 lm·W−1. At 2.0 wt%, a neutral WLED was obtained, its CCT was 4293 K, CRI was 79.6, chromaticity coordinate was (0.36, 0.34) and η L was 19.71 lm·W−1. At 2.5 wt%, a warm WLED was obtained, its CCT was 3348 K, CRI was 69.4, chromaticity coordinate was (0.42, 0.42) and η L was 18.81 lm·W−1. The results suggested the COF can be used promising metal-free phosphors in WLEDs. [Display omitted] • A sp2-carbon-linked covalent organic framework (COF) containing tetraphenylethene units was synthesized. • The COF emitted bright yellow light with a solid-state photoluminesce quantum yield (PLQY) of 39.2%. • The thermal decomposition temperature (T d) of the COF was as high as 610 °C. • Cold/neutral/warm white LEDs with high performances were prepared by using the COF and blue-emitting chips. [ABSTRACT FROM AUTHOR]

In the extreme environment, the signal of the target object is very weak, even reaching the photon level. The single-photon detection technology can detect the weak signal effectively. Ghost imaging (GI) system with single-photon detection technology has a good application in weak light imaging, but the quality of the photon-level GI is still poor. In this paper, we develop a conditional generative adversarial network (CGAN) algorithm to restore images, and the network is trained with simulation data. The results show that the CGAN algorithm has an excellent performance, and the average PSNR and SSIM of test results increase to about 20.8 dB and 0.87 respectively, proving the proposed method is feasible. It is of great significance for imaging under low photon conditions. [ABSTRACT FROM AUTHOR]

A novel reddish-orange-emitting cationic iridium(III) complex [(PPP) 2 Ir(BPPO)]PF 6 (PPP: 2-(4-pentylphenyl)pyridine; BPPO: 2-(4-(tert -butyl)phenyl)-5-(pyridin-2-yl)-1,3,4-oxadiazole) was synthesized and doped in silica gel via a simple sol-gel method. By comparing photoluminescence (PL) intensity of the composites containing [(PPP) 2 Ir(BPPO)]PF 6 at different doping concentrations, the composite containing 12.5 wt% [(PPP) 2 Ir(BPPO)]PF 6 was determined as the best target product due to its highest PL intensity. This composite showed higher thermal stability and lower thermal quenching property than those of pure [(PPP) 2 Ir(BPPO)]PF 6 , their thermal decomposition temperatures (T d) were 350 °C and 320 °C, their PL intensities at 150 °C were 70.8% and 35.8% of those at 30 °C, respectively. Excited by blue-emitting GaN-based chips, both of pure [(PPP) 2 Ir(BPPO)]PF 6 and the composite can be used as phosphors for fabricating reddish-orange LEDs. Moreover, the cold white light of the LEDs fabricated by blue-emitting GaN-based chips and yellow-emitting Y 3 Al 5 O 12 :Ce3+ (YAG:Ce) can be adjusted into neutral/warm white with good performances when pure [(PPP) 2 Ir(BPPO)]PF 6 or the composite was added in the LEDs as red light sources. Relatively, the LEDs using the composite were much more efficient than the LEDs directly using pure [(PPP) 2 Ir(BPPO)]PF 6 at the same amounts. Cationic iridium(III) complexes being doped into silica gel is an effective way for their application as phosphors in LEDs. [Display omitted] • A novel reddish-orange-emitting cationic iridium(III) complex was synthesized and doped in silica gel. • The complex in silica gel showed higher luminous efficiency, higher thermal stability and lower thermal quenching than the pure complex. • Efficient neutral and warm white light-emitting diodes were fabricated by using the composite and Y 3 Al 5 O 12 :Ce3+ as phosphors. [ABSTRACT FROM AUTHOR]

Aerosol pollution has become an increasingly serious problem in China. Among the multiple factors causing aerosol pollution, wildfires in China are occurring more frequently and have gradually become one of the most important contributing factors. However, little is known about their potential causality trends or spatial characteristics. In this research, satellite data of fire events and atmospheric aerosol datasets from 2001 to 2016 were applied in the geographical, statistical "Geodetector model" (GDM) to better understand their causal relationship. From long term observation data in China, we found that the increase in wildfires over the study period greatly enhanced their impacts on the aerosol optical depth (AOD) in recent years. The contribution of burning areas to AOD was 18.29% in 2001 and increased to 38.94% in 2016, and the contribution of fire radiative power (FRP) was 18.80% in 2001 and became 36.05% in 2016. In addition, seasonal research suggested that wildfires contributed rapidly to aerosol pollution, usually from April to September. The regional results in China showed that wildfires can be a relatively dominant factor for aerosol pollution in the southern regions, so that more importance should be attached to the complicated pollution conditions. Overall, our findings highlight the causal effects of wildfires on atmospheric aerosol pollution in China. We suggest that the rising contributions of wildfires to AOD in China should be noticed, and attention should be given to adaptions to local conditions regarding wildfires and aerosol pollution management. [Display omitted] [ABSTRACT FROM AUTHOR]

A reddish-orange-emitting cationic iridium(III) complex [(dfppy) 2 Ir(EPTC)]PF 6 (dfppy: 2-(2,4-difluorophenyl)pyridine, EPTC: 9-ethyl-3-(3-(pyridin-2-yl)-1,2,4-triazin-5-yl)-9 H -carbazole) containing a carbazole-triazine bipolar unit was synthesized. The thermal decomposition temperature (T d) of the complex was 355 °C, its relative emission intensity at 100 °C was 78.6% of that at 20 °C, which was enough for it to be used in LEDs. Mainly due to the bipolar unit, [(dfppy) 2 Ir(EPTC)]PF 6 can efficiently absorb and be excited by blue light (λ em,max = 457 nm) of GaN chips. Excited by blue-emitting GaN chips, the complex can be used for fabricating reddish-orange LEDs, moreover, together with yellow-emitting Y 3 Al 5 O 12 :Ce3+ (YAG:Ce), neutral and warm white light-emitting diodes (WLEDs) can be obtained with good performances. When [(dfppy) 2 Ir(EPTC)]PF 6 was blended in silicone at 1.0, 1.5 and 2.0 wt% respectively, all together with YAG:Ce at 4.0 wt%, three efficient neutral WLEDs were obtained. Their correlate color temperatures (CCT) were 4874 K, 4312 K and 3665 K, color rendering indexes (CRI) were 80.2, 78.3 and 76.4, luminous efficiencies (η L) were 88.5 lm·W−1, 83.6 lm·W−1 and 67.4 lm·W−1, Commission International de I'Eclairage (CIE) values were (0.34, 0.32), (0.36, 0.33) and (0.38, 0.33) respectively. When blending concentration of [(dfppy) 2 Ir(EPTC)]PF 6 was increased to 2.5 wt% together with YAG:Ce still at 4.0 wt%, a warm WLED was obtained, its CCT was 3282, CRI was 73.9, η L was 63.0 lm·W−1, and CIE value was (0.40, 0.35). Image 1 • A reddish-orange-emitting cationic iridium(III) complex containing a carbazole-triazine bipolar unit.. • The complex can be efficiently excited by blue-emitting GaN chips mainly due to the effect of the bipolar unit. • Together with Y 3 Al 5 O 12 :Ce3+ as phosphors, neutral and warm white light-emitting diodes can be obtained with good performances. [ABSTRACT FROM AUTHOR]

In this work, we present a novel single-phase red phosphor of Cs 2 NaAlF 6 :Mn4+ with two Al3+ lattice sites, which shows two groups of vibrational phonon sidebands and ultra-intense zero phonon line (ZPL) under blue light illumination. The evidences have shown that the interesting spectral features originate from the non-equivalent occupation of Mn4+ for both Al3+ sites, which induces the neighboring cation vacancies surrounding Mn4+ and highly distorted [MnF 6 octahedral in the Cs 2 NaAlF 6 host. The luminescent behavior of double sites occupied by Mn4+ can absorb researchers' interest on novel red-emitting phosphors. Profiting from the photoluminescence (PL) features, superior color rendering index of R a = 90.3, R 9 = 81, and low correlated color temperature of T c = 3967 K are achieved from white light-emitting diode (LED) by using yellow Y 3 Al 5 O 12 :Ce3+ (YAG) and red Cs 2 NaAlF 6 :Mn4+ phosphors as blue light converters. These results suggest that Cs 2 NaAlF 6 :Mn4+ for phosphor has a stupendous potential for LED lighting. A novel red phosphor of Cs 2 NaAlF 6 :Mn4+ with unprecedented spectral features of double vibrational phonon sidebands and ultra-intense ZPL comparable to the sharpest v 6 peak under blue light excitation was obtained. The amazing spectral feature is originated from the non-equivalent occupation of Mn4+ for both Al3+ sites in CNAF host. Profiting from the extraordinary PL properties, excellent optical performance of CNAF:Mn as color converter is achieved, implying its potential application in white LED lighting or display devices. Image 1 • A novel red-emitting phosphor of Cs 2 NaAlF 6 :Mn4+ has been successfully synthesized. • The crystal structure of Cs 2 NaAlF 6 :Mn4+ has been confirmed. • The spectral feature with ultra-intense zero phonon line has been elucidated. • Double sites occupancy of Mn4+ in Cs 2 NaAlF 6 has been verified. [ABSTRACT FROM AUTHOR]

One new kind of red-emitting oxyfluoride phosphors Rb 2 WO 2 F 4 doped with different Mn4+ contents were synthesized via a facile co-precipitation method at an ambient condition. Meanwhile, the luminescent behaviors of Mn4+ in Rb 2 WO 2 F 4 were investigated in detail. The sample prepared with the WO 3 /K 2 MnF 6 molar ratio of 40:1 has a broad excitation band around 465 nm and emits a series of sharp-emitting peaks around 631 nm. The crystal-field strength D q as well as Racah parameters B and C were calculated to be 2151, 583 and 3872 cm−1, meaning that Mn4+ in Rb 2 WO 2 F 4 experiences a strong crystal field. The luminescence decay time was also determined to be 2.15 ms. Finally, a warm white LED was obtained using Rb 2 WO 2 F 4 :Mn4+ as red component. It's color rendering index was improved to 81.4 and color temperature was decreased to 3588 K. Image 1 • New red phosphor Rb 2 WO 2 F 4 :Mn4+ was synthesized by facile co-precipitation method. • Rb 2 WO 2 F 4 :Mn4+ yields narrow-band emission around 631 nm. • The optimum concentration of Mn4+ has been confirmed to be about 11 mol%. [ABSTRACT FROM AUTHOR]

The Beibu Gulf Economic Rim of China is a key economic region in China as demonstrated by the "Beibu Gulf Cities Development Project" (2017) that plans to build a "Blue Livable Gulf" to balance environmental protection while providing sustainable economic development. This region has significant energy needs and is predicted to exhibit rapid growth in the future. By means of meteorological observations located at seven islands, a comprehensive statistical analysis on wind energy potential in the northern coastal part of the Beibu Gulf is conducted in this study. Specifically, wind speed, Weibull parameters, wind power density, as well as wind directions on various timescales are analyzed. The analysis shows that annual mean wind power density during 2010–2017 at 100 m above mean sea level was, respectively, 605.6, 542.0, 368.0, 282.0, 265.6, 87.6 and 321.5 W m-2 at the seven sites, with average value of 353.2 W m-2. Evidently, wind power potential demonstrates intra-annual variability, with greatest values occurring in December, while another peak value is observed in July. Wind speeds are lowest in May with another trough occurring in August. The data also display weak inter annual variability. The prevailing wind directions in the rim are mainly from opposing directions of N (winter and autumn) and S (summer). • An assessment on wind energy potential in the Beibu Gulf of the South China Sea was conducted for the period 2010-2017. • Wind power development in the study area has its own unique advantages, including policy and geographic advantages. • Intra-annual variability of wind power in the study area was evident for the period 2010-2017. • The Beibu Gulf evidently has vast resources of wind energy that will reduce its dependency on imported fossil fuels. [ABSTRACT FROM AUTHOR]

A novel red-emitting phosphor K 2 [MoO 2 F 4 ]•H 2 O:Mn4+ prepared by a simple precipitation method emits the intense red light with the high internal quantum efficiency of 86.5% and the high thermal stability of luminescence. A w-LED fabricated with this red phosphor shows intense warm white-light with a high color rendering index of 94, a low correlated color temperature of 3945 K. Therefore, K 2 [MoO 2 F 4 ]•H 2 O:Mn4+ maybe find application on w-LED lighting. • K 2 [MoO 2 F 4 ]•H 2 O:Mn4+ was designed and synthesized by a simple precipitation method. • This phosphor exhibits intense red-emission and high internal quantum efficiency. • This phosphor has the high thermal stability of luminescence. • A w-LED coating this sample has excellent photoelectric performances. A red-emitting phosphor K 2 [MoO 2 F 4 ]•H 2 O:Mn4+ (denoted as KMOF:Mn4+) was designed and synthesized by a simple precipitation method, and its structure and luminescence properties were studied in details. The as-prepared KMOF:Mn4+ phosphors show broad excitation band in the blue-light region. The as-optimized phosphor KMOF:Mn4+ (3.28 mol%) has the strongest red-emission with high internal quantum efficiency of 86.5% among these samples with different contents of Mn4+. Meanwhile, this sample is of the high thermal stability of luminescence. One white light-emitting diode (w-LED) was fabricated by coating KMOF:Mn4+ (3.28 mol%) and Y 3 Al 5 O 12 :Ce3+ on a GaN chip. This w-LED can emit intense warm white-light and show excellent photoelectric performances with a high color rendering index of 94, a low correlated color temperature of 3945 K, and the high luminous efficiency of 150.1 lm/W. Hence, KMOF:Mn4+ (3.28 mol%) could be a promising red phosphor for w-LEDs. [ABSTRACT FROM AUTHOR]

Line edge roughness (LER) has been an important issue in the nanofabrication research, especially in integrated circuits. Despite numerous research studies has made efforts on achieving smaller LER value, a strategy to achieve sub-nanometer level LER still remains challenging due to inability to deposit energy with a profile of sub-nanometer LER. In this work, we introduce a strategy to fabricate structures with sub-nanometer LER, specifically, we use scanning helium ion beam to expose hydrogen silsesquioxane (HSQ) resist on thin SiNx membrane (∼20 nm) and present the 0.16 nm spatial imaging resolution based on this suspended membrane geometric construction, which is characterized by scanning transmission electron microscope (STEM). The suspended membrane serves as an energy filter of helium ion beam and due to the elimination of backscattering induced secondary electrons, we can systematically study the factors that influences the LER of the fabricated nanostructures. Furthermore, we explore the parameters including step size, designed exposure linewidth (DEL), delivered dosage and resist thickness and choosing the high contrast developer, the process window allows to fabricate lines with 0.2 nm LER is determined. AFM measurement and simulation work further reveal that at specific beam step size and DEL, the nanostructures with minimum LER can only be fabricated at specific resist thickness and dosage., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

We have developed a photocatalyst-free reaction system that uses Hantzsch esters as photoreducing agents to promote the coupling of carbonyl compounds to 1,2-diols. The system fully utilizes the single electron transfer and proton donor roles of Hantzsch esters. The system shows a wide range of substrate application. Aromatic ketones, aliphatic ketones, and aldehydes can be applied to the catalytic system. Both self-coupling and cross-coupling can achieve ideal results.

Stretchable electronics commonly assemble multiple material modules with varied bulk moduli and surface chemistry on one packaging substrate. Preventing the strain-induced delamination between the module and the substrate has been a critical challenge. Here we develop a packaging substrate that delivers mechanically stable module/substrate interfaces for a broad range of stiff and stretchable modules with varied surface chemistries. The key design of the substrate was to introduce module-specific stretchability and universal adhesiveness by regionally tuning the bulk molecular mobility and surface molecular polarity of a near-hermetic elastic polymer matrix. The packaging substrate can customize the deformation of different modules while avoiding delamination upon stretching up to 600%. Based on this substrate, we fabricated a fully stretchable bioelectronic device that can serve as a respiration sensor or an electric generator with an in vivo lifetime of 10 weeks. This substrate could be a versatile platform for device assembly., (© 2024. The Author(s).)

In microfluidic systems, it is important to maintain flow stability to execute various functions, such as chemical reactions, cell transportation, and liquid injection. However, traditional flow sources, often bulky and prone to unpredictable fluctuations, limit the portability and broader application of these systems. Existing fluidic stabilizers, typically designed for specific flow sources, lack reconfigurability and adaptability in terms of the stabilization ratios. To address these limitations, a modular and standardized stabilizer system with tunable stabilization ratios is required. In this work, we present a Lego-like modular microfluidic stabilizer system, which is fabricated using 3D printing and offers multi-level stabilization combinations and customizable stabilization ratios through the control of fluidic RC constants, making it adaptable to various microfluidic systems. A simplified three-element circuit model is used to characterize the system by straightforwardly extracting the RC constant without intricate calculations of the fluidic resistance and capacitance. By utilizing a simplified three-element model, the stabilizer yields two well-fitted operational curves, demonstrating an R-square of 0.95, and provides an optimal stabilization ratio below 1%. To evaluate the system's effectiveness, unstable input flow at different working frequencies is stabilized, and droplet generation experiments are conducted and discussed. The results show that the microfluidic stabilizer system significantly reduces flow fluctuations and enhances droplet uniformity. This system provides a new avenue for microfluidic stabilization with a tunable stabilization ratio, and its plug-and-play design can be effectively applied across diverse applications to finely tune fluid flow behaviors in microfluidic devices.