Search

Sulfate crystals typically exhibit minimal optical anisotropy due to the near‐zero polarizability anisotropy (δ) of [SO4]2− tetrahedra, arising from highly symmetrical electron clouds. Recent research sought to enhance δ via chemical modifications, such as fluorination. However, the resultant crystals often maintain subpar optical anisotropy, frequently with birefringence values below 0.1. In this study, we have uncovered that δ can be significantly strengthened by chemically tailoring the tetrahedral [SO4]2− with anisotropic π‐conjugated modules. This has been demonstrated by several newly proposed S−O‐Org (Org: π‐conjugated organic species) moieties, which show a sharp increase in δ based on theoretical computations. To further validate this experimentally, we synthesized and characterized six new 3‐pyridinesulfonate crystals with the formula A(3‐C5H4NSO3) ⋅ xH2O (A=Li, Ag, K, Rb, Cs, and NH4; x=0 and 1). Notably, these materials exhibit strong optical anisotropy, with birefringence values ranging from 0.240 to 0.312 at 546 nm. These values are approximately 23 to 145.5 times greater than those of corresponding sulfates, and they outperform a vast number of sulfate‐related optical materials, thus verifying the effectiveness of the proposed strategy. Furthermore, the title compounds exhibit diverse microstructure peculiarities influenced by the size and binding natures of the counter cations. [ABSTRACT FROM AUTHOR]

Sulfate crystals typically exhibit minimal optical anisotropy due to the near‐zero polarizability anisotropy (δ) of [SO4]2− tetrahedra, arising from highly symmetrical electron clouds. Recent research sought to enhance δ via chemical modifications, such as fluorination. However, the resultant crystals often maintain subpar optical anisotropy, frequently with birefringence values below 0.1. In this study, we have uncovered that δ can be significantly strengthened by chemically tailoring the tetrahedral [SO4]2− with anisotropic π‐conjugated modules. This has been demonstrated by several newly proposed S−O‐Org (Org: π‐conjugated organic species) moieties, which show a sharp increase in δ based on theoretical computations. To further validate this experimentally, we synthesized and characterized six new 3‐pyridinesulfonate crystals with the formula A(3‐C5H4NSO3) ⋅ xH2O (A=Li, Ag, K, Rb, Cs, and NH4; x=0 and 1). Notably, these materials exhibit strong optical anisotropy, with birefringence values ranging from 0.240 to 0.312 at 546 nm. These values are approximately 23 to 145.5 times greater than those of corresponding sulfates, and they outperform a vast number of sulfate‐related optical materials, thus verifying the effectiveness of the proposed strategy. Furthermore, the title compounds exhibit diverse microstructure peculiarities influenced by the size and binding natures of the counter cations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly active CeO 2 /CuCo NPs were supported on hollow N-doped carbon spheres. • The catalyst facilitated AB hydrolysis and one-pot tandem reduction of 4-nitrophenol. • Noble metal-comparable catalytic performance was achieved with exceptional TOF of 2830.2 h−1. • Broad substrate scope was utilized including various aromatic nitro compounds. It's a safe method to use high hydrogen density ammonia borane (AB) to facilitate the tandem hydrogenation of aromatic nitro compounds. While a major problem for tandem hydrogenation, the development of non-noble metal catalysts with high activity and stability is encouraging. This work involved the synthesis of highly active CeO 2 /CuCo nanoparticles support on hollow N-doped carbon spheres and its investigation for AB hydrolysis, taking into account the impacts of the HNCSs and CeO 2 supports. Because CuCo alloy, CeO 2 , and HNCSs supports worked in concert, HNCSs@CeO 2 /CuCo was found to be the best catalyst. The activation energy achieved was comparable to the reported Pd- and Pt-based catalysts, with a value as low as 21.8 kJ/mol. Using AB as the in-situ H 2 source, HNCSs@CeO 2 /CuCo exhibited a significant degree of activity in the one-pot tandem reduction of 4-NP with the turnover frequency of 2830.2 h−1, even surpassing over ten times of some noble metal catalysts. Following five consecutive cycles of reaction condition tuning, the HNCSs@CeO 2 /CuCo catalyst demonstrated a constant conversion efficiency. Also, the catalyst's uses for one-pot tandem reduction of other highly active aromatic nitro compounds were expanded. [ABSTRACT FROM AUTHOR]

Magnesium is essential for cellular life, but how it is homeostatically controlled still remains poorly understood. Here, we report that members of CNNM family, which have been controversially implicated in both cellular Mg2+ influx and efflux, selectively bind to the TRPM7 channel to stimulate divalent cation entry into cells. Coexpression of CNNMs with the channel markedly increased uptake of divalent cations, which is prevented by an inactivating mutation to the channel's pore. Knockout (KO) of Trpm7 in cells or application of the TRPM7 channel inhibitor NS8593 also interfered with CNNM-stimulated divalent cation uptake. Conversely, KO of CNNM3 and CNNM4 in HEK-293 cells significantly reduced TRPM7-mediated divalent cation entry, without affecting TRPM7 protein expression or its cell surface levels. Furthermore, we found that cellular overexpression of phosphatases of regenerating liver (PRLs), known CNNMs binding partners, stimulated TRPM7-dependent divalent cation entry and that CNNMs were required for this activity. Whole-cell electrophysiological recordings demonstrated that deletion of CNNM3 and CNNM4 from HEK-293 cells interfered with heterologously expressed and native TRPM7 channel function. We conclude that CNNMs employ the TRPM7 channel to mediate divalent cation influx and that CNNMs also possess separate TRPM7-independent Mg2+ efflux activities that contribute to CNNMs' control of cellular Mg2+ homeostasis. Magnesium is essential for cellular life, but how is it homeostatically controlled? This study shows that proteins of the CNNM family bind to the TRPM7 channel to stimulate divalent cation entry into cells, independent of their function in regulating magnesium ion efflux. [ABSTRACT FROM AUTHOR]

Keywords: Birefringence; Optical Anisotropy; Sulfate Crystals; TetrahedraA design strategy for significantly enhancing the polarizability anisotropy of isotropic tetrahedra in sulfate crystals is reported by Zhiyong Bai and Kang Min Ok in their Research Article (e202315311). This strategy involves chemically alternating tetrahedral [SO4]2− units with π‐conjugated organic groups. Experimental validation of the approach utilized 3‐pyridinesulfonate anion functional building blocks for crystal synthesis...By Zhiyong Bai and Kang Min OkReported by Author; Author [Extracted from the article]

Keywords: Birefringence; Optical Anisotropy; Sulfate Crystals; TetrahedraA design strategy for significantly enhancing the polarizability anisotropy of isotropic tetrahedra in sulfate crystals is reported by Zhiyong Bai and Kang Min Ok in their Research Article (e202315311). This strategy involves chemically alternating tetrahedral [SO4]2− units with π‐conjugated organic groups. Experimental validation of the approach utilized 3‐pyridinesulfonate anion functional building blocks for crystal synthesis...By Zhiyong Bai and Kang Min OkReported by Author; Author [Extracted from the article]

We report a new strongly birefringent material, [Al(H2O)6](IO3)2(NO3) (AINO). Based on a detailed analysis, we concluded that its enhanced birefringence (0.253 at 546 nm) predominantly resulted from a synergy of the effects of its (NO3)− and (IO3)− functional motifs, combined with an equally important and indispensable optimal arrangement of these two groups in the structure. This work has provided insight for discovering new birefringent materials. [ABSTRACT FROM AUTHOR]

• Tm3+:Ca 10 Li(VO 4) 7 crystal was grown successfully by Czochralski method. • Thermal and spectral properties of Tm3+:Ca 10 Li(VO 4) 7 crystal were presented. • Tm3+:Ca 10 Li(VO 4) 7 crystal is a promising candidate for solid state tunable laser at around 2 µm. The single crystal Tm3+:Ca 10 Li(VO 4) 7 with dimensions of Ø 23 × 25 mm3 was grown by Czochralski method. It's thermal and spectroscopic properties were investigated. The thermal expansion coefficient α a is 1.671 × 10−5 K−1 and α c is 1.462 × 10−5 K−1. The absorption cross-sections at 794 nm are 2.43 × 10−20 cm2 and 1.04 × 10−20 cm2 for π - and σ- polarization, respectively. The largest stimulated emission cross-section corresponding to the 3F 4 → 3H 6 transition of Tm3+ ions, is 1.92 × 10−20 cm2 at 1883 nm for π- polarization and 1.69 × 10−20 cm2 at 1917 nm for σ- polarization. The fluorescence lifetime is 1.05 ms. The broad and smooth gain profile from 1750 nm to 2010 nm means that Tm3+:Ca 10 Li(VO 4) 7 is a potential laser crystal for tunable and ultrashort pulse lasers near 2 µm. [ABSTRACT FROM AUTHOR]

[Display omitted] • Precise aliovalent chemical substitutions on B-site cations are presented. • Seven groups of d0 transition metal/gallium based nonlinear optical iodates and selenites are reviewed. • Factors affecting second-harmonic generation and band gap are outlined. • Several new nonlinear optical materials are designed and predicted. As an important class of solid-state functional materials, nonlinear optical (NLO) crystals have attracted enormous academic and industrial interest due to their unique ability to generate lasers at a variety of inaccessible wavelengths. A promising NLO material must meet several requirements, including noncentrosymmetric structure, a strong second-harmonic generation (SHG) response, sufficient birefringence (Δ n), and a wide transparency window. The rarity of noncentrosymmetric structures and the three rigorous yet contradictory performance criteria pose significant challenges for the development of NLO materials with desired properties. Therefore, it is imperative to develop effective strategies to achieve the goal of rational design of NLO candidates. Among many, chemistry-directing substitution from existing prototypes has proven to be a promising and accessible approach. In this Review, our aim is to provide useful insights for the discovery of new NLO materials by highlighting how to implement precise aliovalent chemical substitution tactics targeting B-site cations to design novel functional NLO materials. For this purpose, we chose early d0-transition metal (d0-TM) and gallium cations-based iodates and selenites due to their structural diversity and abundant sources. The B-site cations, d0-TM and gallium ions, have sequentially variable oxidization states from hexavalent to trivalent states, providing an ideal platform for inequivalent substitution. In the first section, we describe the three types of distortion of d0-TM cation-centered octahedra and briefly explain the aliovalent substitution strategy. To differentiate the concept of fundamental building units (FBUs) or basic building units (BBUs), we adopt secondary building units (SBUs) to specifically describe the structural fragments generated by the connections of [MX 6 ] (M = TM or Ga cations, X = O or F ligands) octahedra with iodate or selenite groups. Next, we provide seven sets of examples to meticulously illustrate the precise aliovalent chemical substitution on B-site cations and discuss the crystal structure and functional properties. We also rationally design and predict several new NLO candidates based on the above-mentioned pathways. Finally, we discuss several factors that affect the functional properties of NLO materials. [ABSTRACT FROM AUTHOR]

Benefiting from high transmittance of PO4 tetrahedra in the deep-ultraviolet (deep-UV) region, phosphates have been investigated as deep-UV nonlinear optical (NLO) candidates for years. So far, reported deep-UV NLO phosphates are orthophosphates and polyphosphates while cyclophosphates, important members of the phosphates family, have usually been neglected for use as deep-UV NLO crystals. Here, we first report a novel cyclotetraphosphate K2SrP4O12 (KSPO) as a deep-UV transparent NLO crystal. In its structure, the fundamental building groups are ring [P4O12]4− groups. KSPO exhibits a moderate second-harmonic generation (SHG) response that is 0.5 times that of KH2PO4 (KDP) and a short deep-ultraviolet absorption edge smaller than 200 nm. [ABSTRACT FROM AUTHOR]

Ultrasound-based carotid elastography has been developed to evaluate the vulnerability of carotid atherosclerotic plaques. The aim of this study was to investigate the in vivo interoperator reproducibility of carotid elastography for the identification of vulnerable plaques, with high-resolution magnetic resonance imaging (MRI) as reference. Ultrasound radio-frequency data of 45 carotid arteries (including 53 plaques) from 32 volunteers were acquired separately by two experienced operators in the longitudinal view and then were used to estimate the interframe axial strain rate (ASR) with a two-step optical flow method. The maximum 99th percentile of absolute ASR of all plaques in a carotid artery was used as the elastographic index. MRI scanning was also performed on each volunteer to identify the vulnerable plaque. The results showed no systematic bias in the Bland–Altman plot and an intraclass correlation coefficient of 0.66 between the two operators. In addition, no statistical significance was found between the receiver operating characteristic (ROC) curves from the two operators ($p >0.05$), and their areas under the ROC curves were 0.83 and 0.77, respectively. Using the mean measurements of the two operators as the classification criterion, a sensitivity of 71.4%, a specificity of 87.1%, and an accuracy of 82.2% were obtained with a cutoff value of 1.37 $\text{s}^{-1}$. This study validates the interoperator reproducibility of ultrasound-based carotid elastography for identifying vulnerable carotid plaques. [ABSTRACT FROM AUTHOR]

In dry centrifugal granulation technology, the liquid slag is granulated in the granulator to produce a particle population with a high-temperature dilute-phase distribution. During the falling process, inadequate heat transfer can cause the droplets to fail to solidify completely, greatly reducing the safety of the heat recovery bed operation. In this work, A heat transfer model for a particle population of ultra-dilute phase slag was developed, to investigate the particle-fluid-surface heat transfer characteristics of the particle population around the tube, and obtain the changing law of particle population cooling and tube surface heat transfer characteristics. The conclusions of the study show that the fluid flows close to the tube, which is due to particle perturbation. The separation point is to be shifted back, from 180°∼210° to the top 90°∼120°, resulting in a local heat transfer coefficient maximum at the upper of the tube. The amplitude of the fluctuations in the local heat transfer coefficients exhibits the dominance of the different heat transfer types, the percentage of radiant heat transfer is above 60% in all cases. The extended particle residence time can effectively increase the particle cooling rate, the particle cooling rate is above 230 K/s. This study reveals the heat exchange mechanism between the gas-solid phase of the ultra-dilute particle population and the horizontal tube during the falling process, positive performance of horizontal tubes on heat transfer to particle populations was confirmed. Combined heat transfer between the surfaces of dilute-phase particle populations is proposed as a new research content in the field of high-temperature melt granulation, expanding the prospects of industrial applications of combined heat transfer between the surfaces of fluid-solid multiphase flows. • A new method for enhanced heat transfer in slag particle is proposed. • The combined heat transfer mechanism of gravity-driven particle population. • The effects of different factors on the heat transfer were analyzed. [ABSTRACT FROM AUTHOR]

Catalytic ozonation utilizes catalysts to improve the decomposition of ozone and the formation of hydroxyl radicals, which can overcome some disadvantages of ozonation. Fe-based materials are widely used as catalysts for heterogeneous catalytic ozonation due to their easy preparation, excellent catalytic performance and the abundance of Fe in nature. In this paper, the performances of various Fe-based catalysts, including Fe 0 -derived, FeOOH-derived, Fe 2 O 3 -derived, Fe 3 O 4 -derived and iron oxides composite, their preparation and characterization methods were briefly introduced. The catalytic ozonation using Fe-based catalysts for the degradation of various emerging contaminants, such as pesticides and herbicides, pharmaceuticals, phthalic acid esters, dyes, nitrobenzenes, phenols, as well as for the treatment of actual wastewater was summarized. The main influencing factors on catalytic ozonation of toxic organic pollutants were discussed, and their potential applications and perspectives were proposed. [ABSTRACT FROM AUTHOR]

Iron oxyhydroxides (FeOOH) are common crystalline forms of iron which play an important role in catalysis through a series of reduction-oxidation reactions. In this paper, Ce substituted goethite (Ce 0.1 Fe 0.9 OOH) was prepared by isomorphous substitution method, characterized by XRD, SEM, TEM-EDS, FTIR, and used for the catalytic ozonation of sulfamethazine (SMT). The results showed that the catalyst can significantly enhance the mineralization of SMT, and more than 42.1% SMT were mineralized in the presence of the catalyst, which is 1.74 times higher than ozonation alone. Moreover, with addition of catalyst, more ozone was dissolved into solution. The solution pH decreased due to small-molecule organic acids formation. The catalytic activity decreased slightly during the repeated batch experiments, due to the corrosion of the catalyst and the adsorption of the residual intermediates on the catalyst surface. [ABSTRACT FROM AUTHOR]

Ce substituted goethite (Ce 0.1 Fe 0.9 OOH) was prepared by isomorphous substitution method and used for the catalytic ozonation of sulfamethazine (SMT). The results showed that acidic and neutral pH is beneficial for SMT mineralization. The mineralization efficiency of SMT was enhanced obviously in the presence of catalyst. Major degradation products of SMT during catalytic ozonation process were quantified and compared at acidic or basic conditions. Among the intermediates, 2-amine-4,6-dimethylpyrimidin accounted for high proportion. The small-molecule organic acids accumulated, which can inhibit the degradation reaction by lowering solution pH value. Based on the competitive degradation results of the intermediates and SMT, the possible pathways for SMT degradation by catalytic ozonation were tentatively proposed. [ABSTRACT FROM AUTHOR]

A novel bend-insensitive long period fiber grating (LPFG) is presented and applied in high temperature measurement. This LPFG is formed by periodically arranging three micro-core-offsets fabricated by employing the cleaving–splicing method in the standard single mode fiber. As bend is applied onto the LPFG along the most bend-insensitive orientation, the resonant wavelength sensitivity of the transmission spectrum is 0.0097 nm/m −1 for a curvature range of 0–3.5 m −1 , which is about three orders lower than those of the conventional gratings. For other orientations of the LPFG, the bend sensitivities are also one or two orders lower than those of conventional ones. This better bend characteristic could be used to improve the sensing performances of the LPFG, such as improving the measurement accuracy and resolving cross sensitivity issue between bend and other parameters. Moreover, since the mode coupling of the LPFG results from the fiber geometry deformation which indicates a better thermal stability, the LPFG could be used for high temperature measurement occasions. [ABSTRACT FROM AUTHOR]

A new long period fiber grating (LPFG) fabrication method based on periodically arranging a series of waist-enlarged fusion bitapers (WFBs) along the axis of a standard single mode fiber has been proposed and experimentally demonstrated. A strong grating modulation induced by the WFBs excites the mode coupling between the core and cladding modes, resulting in the formation of a grating resonance band. The mode coupling strength is directly proportional to the number of WFBs. A compact WFB-LPFG with a length of 3.28 mm has been achieved by five periods and displays a contrast of over 30 dB. By measuring the transmission intensity and resonant wavelength shift of the transmission spectrum, strain and temperature can be simultaneously determined. [ABSTRACT FROM AUTHOR]

Abstract: SNARE domain proteins are key molecules mediating intracellular fusion events. SNAP25 family proteins are unique target-SNAREs possessing two SNARE domains. Here we report the genetic, molecular, and cell biological characterization of C. elegans SNAP-29. We found that snap-29 is an essential gene required throughout the life-cycle. Depletion of snap-29 by RNAi in adults results in sterility associated with endomitotic oocytes and pre-meiotic maturation of the oocytes. Many of the embryos that are produced are multinucleated, indicating a defect in embryonic cytokinesis. A profound defect in secretion by oocytes and early embryos in animals lacking SNAP-29 appears to be the underlying defect connecting these phenotypes. Further analysis revealed defects in basolateral and apical secretion by intestinal epithelial cells in animals lacking SNAP-29, indicating a broad requirement for this protein in the secretory pathway. A SNAP-29-GFP fusion protein was enriched on recycling endosomes, and loss of SNAP-29 disrupted recycling endosome morphology. Taken together these results suggest a requirement for SNAP-29 in the fusion of post-Golgi vesicles with the recycling endosome for cargo to reach the cell surface. [Copyright &y& Elsevier]

• Flowerlike PtPd NPs loaded on Hollow nitrogen-doped carbon spheres were prepared. • PtPd/HNCSs exhibited superior catalytic performance for MOR, EOR and EGOR. • Studies on tolerance to CO poisoning and kinetics were carried out. • After 200 scanning cycles, the catalyst kept high normalized current. The development of high active and durable electrocatalysts is of critical importance for the commercial viability of direct alcohol fuel cells. Here, hollow N-doped carbon spheres (HNCSs) were prepared by using a polydopamine-assisted method for supporting flowerlike PtPd alloy nanoparticles which were synthesized by the reduction of H 2 PtCl 6 and Na 2 PdCl 4 with ascorbic acid. The effect of Pt-to-Pd molar ratios on the catalytic activity was investigated for methanol, ethanol and ethylene glycol electrooxidation (MOR, EOR and EGOR). Electrochemical measurements demonstrated that PtPd/HNCSs (only 2 wt.%) exhibited higher catalytic activity, stability and tolerance to CO poisoning than commercial Pt/C (20 wt.%) catalyst in the alcohols oxidation. It could be attributed to the structural and compositional advantages of the synergistic effect of Pt and Pd besides large specific surface area and mesoporous structure of HNCSs. After 200 scanning cycles, the peak currents density of Pt 3 Pd 1 /HNCSs still remained 77.8%, 88.9% and 93.9% of the initial cycle in MOR, EOR and EGOR, respectively. Meanwhile, the kinetic study confirmed that the MOR, EOR and EGOR processes were diffusion-controlled and irreversible. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Introduction of the planar organic cation [C(NH2)3]+ into tetrahedronal inorganic arsenate generates a new ultraviolet nonlinear optical crystal triguanidine arsenate dihydrate, [C(NH2)3]3AsO4·2H2O, which exhibits a short ultraviolet absorption edge (210 nm), suitable second-harmonic generation response (0.9 × KDP), and moderate birefringene (0.0387 at 546 nm). Notably, by optimizing the growth conditions, transparent and wafer well-developed bulk single crystals can be easily prepared. [ABSTRACT FROM AUTHOR]

Large birefringence (Δn = 0.277 at 546 nm) and strong second-harmonic generation (SHG) intensity (4.3 × KDP) achieved a remarkable balance in a potential ultraviolet nonlinear optical crystal: 2(C3H7N6)+·2Cl−·H2O. Theoretical calculations showed that planar benzene-like π-conjugated [C3N6] groups had important optical properties. [ABSTRACT FROM AUTHOR]

TRPM7 and TRPM6 were the first identified bifunctional channels to contain their own kinase domains, but how these channel-kinases are regulated is poorly understood. Previous studies identified numerous phosphorylation sites on TRPM7, but very little is known about TRPM6 phosphorylation or sites on TRPM7 transphosphorylated by TRPM6. Our mass spectrometric analysis of homomeric and heteromeric TRPM7 and TRPM6 channels identified phosphorylation sites on both proteins, as well as several prominent sites on TRPM7 that are commonly modified through autophosphorylation and transphosphorylation by TRPM6. We conducted a series of amino acid substitution analyses and identified S1777, in TRPM7's catalytic domain, and S1565, in TRPM7's exchange domain that mediates kinase dimerization, as potential regulatory sites. The phosphomimetic S1777D substitution disrupted catalytic activity, most likely by causing an electrostatic perturbation at the active site. The S1565D phosphomimetic substitution also inactivated the kinase but did so without interfering with kinase dimerization. Molecular modeling indicates that phosphorylation of S1565 is predicted to structurally affect TRPM7's functionally conserved N/D loop, which is thought to influence the access of substrate to the active site pocket. We propose that phosphorylation of S1565 within the exchange domain functions as a regulatory switch to control TRPM7 catalytic activity. [ABSTRACT FROM AUTHOR]

High-accuracy temperature measurement plays a vital role in biomedical, oceanographic, and photovoltaic industries. Here, a highly sensitive temperature sensor is proposed and demonstrated based on cascaded polymer-infiltrated Mach–Zehnder interferometers (MZIs), operating near the dispersion turning point. The MZI was constructed by splicing a half-pitch graded index fiber (GIF) and two sections of single-mode fiber and creating an inner air cavity based on femtosecond laser micromachining. The UV-curable polymer-infiltrated air cavity functioned as one of the interference arms of MZI, and the residual GIF core functioned as the other. Two MZIs with different cavity lengths and infiltrated with the UV-curable polymers, having the refractive indexes on the different sides of the turning point, were created. Moreover, the effects of the length and the bending way of transmission SMF between the first and the second MZI were studied. As a result, the cascaded MZI temperature sensor exhibits a greatly enhanced temperature sensitivity of −24.86 nm/°C based on wavelength differential detection. The aforementioned result makes it promising for high-accuracy temperature measurements in biomedical, oceanographic, and photovoltaic applications. [ABSTRACT FROM AUTHOR]

Catalytic wet air oxidation (CWAO) of fomesafen wastewater was studied using CeO2-TiO2 catalysts. The catalysts were prepared by coprecipitation method and characterized by Brunauer, Emmett, and Teller (BET) surface area, X-ray diffraction, and X-ray photoelectron spectroscopy. In addition, effects of temperature, oxygen partial pressure, and initial pH on the removal efficiency of chemical oxygen demand (COD) were investigated. Moreover, kinetics of CWAO of wastewater of fomesafen production was studied. Results showed that the CeO2-TiO2 catalyst with Ti/Ce of 3:1 had the largest BET surface area. When the reaction temperature was 250°C, oxygen partial pressure was 3 MPa, pH was 5.0, and reaction time was 3 h, the COD removal rate reached 78%. The ratio of biochemical oxygen demand (BOD5) to COD increased from 0.03 to 0.32 after 3 h, which indicated that CWAO can effectively improve the biodegradability of wastewater of fomesafen production. Furthermore, the second-order kinetic model conformed well to experimental data with correlation coefficients greater than 0.90. This is the first study to investigate the CWAO of real wastewater from fomesafen production with CeO2-TiO2 catalyst. This study can add new knowledge to CWAO of the real wastewater of fomesafen production and further enhance the understanding on the function and applicability of CeO2-TiO2 catalyst. [ABSTRACT FROM AUTHOR]

A novel optical fiber sensing technology based on intensity distribution change in orbital angular momentum (OAM) mode is proposed and implemented herein. The technology utilizes a chiral long-period fiber grating (CLPFG) to directly excite the 1st-order OAM (OAM1) mode. The intensity changes in the coherent superposition state between the fundamental mode and the OAM1 mode at the non-resonant wavelength of the CLPFG is tracked in order to sense the external parameters applied to the grating area. Applying this technology to temperature measurement, the intensity distribution change has a good linear relationship with respect to temperature in the range of 30 °C to 100 °C. When the intensity was denoted by the number of pixels with a gray value of one after binarization of collected images, the sensitivity was 103 px/°C and the corresponding resolution was 0.0097 °C. Meanwhile, theoretical and experimental results show that the sensitivity and resolution can be further improved via changing the area of the collected image. Compared with sensing methods based on spiral interference pattern rotation in previous work, this sensing technology has the advantage of exquisite structure, easy realization, and good stability, thus making it a potential application in practices. [ABSTRACT FROM AUTHOR]

A highly sensitive torsion sensor can be constructed by combining a twisted photonic crystal fiber with a liquid-filled waveguide in its air-hole cladding. The torsion sensitivity of this type of sensor is determined directly by the phase-matching conditions between the fiber core mode and the liquid waveguide mode, which can be improved by tuning the helicity (denoted by the initial twist rate, α0) of the twisted photonic crystal fiber. The enhancement mechanism of α0 on the sensitivity of the proposed torsion sensor is investigated theoretically, followed by experimental verifications, and a torsion sensitivity as high as 446 nm∙mm∙rad−1 can be obtained by tailoring these parameters. Experimental results show that the torsion sensitivity increases with α0 decreasing from 3.142 to 3.925 rad/mm, which are in consistence with that of the numerical predictions. The demonstrated torsion sensor is expected to contribute to the development of highly sensitive torsion-related photonic crystal fiber devices. [ABSTRACT FROM AUTHOR]

A novel torsion sensor is proposed, which is composed of one long period fibre grating and one asymmetrically corrugated long period fibre grating based on the high-frequency CO2laser pulses technology and burning fibre coating and etching cladding technology, respectively. By combing the advantages of the two aforementioned elements, a sensitivity of 331.7 and 310.3 pm/(rad/m) towards clockwise and anticlockwise direction, respectively, is reached in the experiments. [ABSTRACT FROM AUTHOR]

Tiny and soft breath sensors offer unique capabilities in a continuous and long-term recording of vital physiological parameters for human health monitoring. Here, we propose an all fiber-optic breath sensor based on helical intermediate-period fiber grating (E-HIPFG) written in an elliptic core polarization-maintaining fiber. This E-HIPFG-based breath sensor shows ultrafast response time and recovery time, which are 34.46 ms and 41.34 ms, respectively. The response time and recovery time are three orders faster than the corresponding values of conventional optical fiber-based breath sensors with humidity-sensitive material. In addition, this sensor does not combine with any additional coating materials or fiber architectures, increasing the stability in a continuous and long-term detection for breath monitoring. The E-HIPFG sensor is insensitive to external influences, such as temperature, torsion and strain, endowing the possibility of stable detection in the moving body. Particularly, the temperature sensitivity of the sensor is 2.75 pm/°C, which is two orders lower than the corresponding value of previous reports. Due to its considerable stability, quick response, and insensitivity to external influences, the E-HIPFG-based breath sensor offers significant potential for long-term and compact breathing monitoring devices. • A breath sensor is designed with elliptical core helical intermediate-period fiber grating (E-HIPFG). • The E-HIPFG is an all-fiber transducer without sensitive material and restructure. • The E-HIPFG sensor gains an ultrafast response time and recovery time. • The E-HIPFG-based breath sensor shows excellent resistance to environmental disturbances. [ABSTRACT FROM AUTHOR]

The degradation of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution has been studied by heterogeneous Fenton-like process using synthetic FeS as a catalyst, and the properties of FeS were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Several operation parameters including pH, FeS dosage, H 2 O 2 concentration and temperature were investigated and the results showed that 2,4-D was efficiently removed from aqueous solution using FeS as a catalyst over a wide range of pH values from 2.0 to 6.5. At the initial pH of 4.5 (without pH adjustment), 10 mM of H 2 O 2 , 10 mg/L of 2,4-D and a FeS dose of 0.5 g/L, 2,4-D was almost completely removed within 300 min and the total organic carbon (TOC) removal could reach 70.4%. The degradation intermediates such as 2,4-dichlorophenol, 2-chlorohydroquinone, 4,6-dichlororesorcinol, 2-chlorobenzoquinone, several short-chain acids and chloride ion have been identified by a gas chromatography mass spectrometry (GC–MS) and an ion chromatography (IC). Based on the findings, a possible reaction pathway was proposed. The results of five consecutive experiments indicated the good stability and reusability of FeS and the scavenging experiments revealed that 2,4-D was mainly decomposed by the attack of HO radicals, especially the surface-bounded HO . [ABSTRACT FROM AUTHOR]

A simple and compact device for simultaneous directional bending and temperature sensing is proposed and demonstrated. The device is constructed by overlapping a long period grating (LPG) on a fiber Bragg grating (FBG), and is capable of measuring the directional bending and the temperature at the same position. The LPG written with CO2 laser irradiation has a cross asymmetrical refractive modulation and the FBG is formed by UV laser exposure in the fiber core. The cross-sensitivity between measurement of the directional bending and of the temperature of an LPG is effectively eliminated by solving a matrix equation, by considering the temperature response characteristics of FBG. Experimental results show that the bending and temperature sensitivities are − 6.819 nm m−1 in a range from −2 to 2 m−1 and 10.25 pm °C−1, respectively. [ABSTRACT FROM AUTHOR]

A highly sensitive and compact fiber-optic sensor for simultaneous measurement of refractive index (RI) and temperature has been proposed and experimentally demonstrated. The device is based on a fiber modal interferometer assisted by an embedded fiber Bragg grating, which helps to resolve the crosstalk issue. The fiber modal interferometer consists of an Up-Fusion-Bitaper (UFBT) pair to excite high-order cladding-modes and re-couple them to the fiber core. For high order cladding mode involved in the interference, the implemented sensor yields high spectral sensitivities of −197.03±7.35nm/RIU (refractive index unit) for a refractive index (RI) range of 1.365–1.415 and 63.7±1.84pm/°C for a temperature range from 20 to 80°C, respectively. Simultaneous measurement of ambient RI and temperature has been experimentally demonstrated. The maximum RI and temperature measurement errors are ±0.00054RIU and ±0.77°C, respectively. These results demonstrate the feasibility of this configuration for reliable RI-based chemical and biochemical monitoring. [ABSTRACT FROM AUTHOR]

Trace amounts of Co3O4 modified TiO2 nanorod arrays were successfully fabricated through the photochemical deposition method without adding any nocuous reagents. The Co3O4/TiO2 nanorod arrays fabricated in acid solution had the highest photo-electrochemical activity. We elaborated on the mechanism of Co3O4-TiO2 fabricated in different pH value solutions. The Co3O4-TiO2 had a more remarkable photo-electrochemical performance than the pure TiO2 nanorod arrays owing to the heterojunction between Co3O4 and TiO2. The degradation of methylene blue and hydroquinone was selected as the model reactions to evaluate the photo-electrochemical performance of Co3O4-TiO2 nanorod arrays. The Co3O4/TiO2 nanorod arrays had great potential in waste water treatment. [ABSTRACT FROM AUTHOR]

This paper reports the chemical synthesis of highly-active Mn 3 O 4 /PdCu nanocomposites coated with N-doped carbon (NC) shell using polydopamine (PDA) as the carbon source, which provides high specific surface area and pore volume. The structure and morphology of Mn 3 O 4 /PdCu@NC nanocomposites were systematically studied. Taking advantage of the synergistic effects of PdCu alloy and Mn 3 O 4 support, the Mn 3 O 4 /PdCu@NC catalyst exhibited an outstanding activity toward the reduction of 4-nitrophenol (4-NP), in comparison to Mn 3 O 4 /PdM@NC (M = Ni, Au, Ag), Mn 3 O 4 /PdCu@PDA, and commercial Pd/C catalyst. Owing to the protection by NC shell, the as-prepared catalyst showed stable conversion efficiency of up to 90% over ten successive cycles. Considering 4-NP as one of the important organic pollutants from industrial production, the effects of various inorganic and organic species on the catalytic efficiency were further tested and most of them had negligible impact. This strategy of utilizing an N-doped carbon shell could be extended to obtain PdCu alloys supported on other metal oxides, making it applicable for applications in treatment of environmental pollutants. Unlabelled Image • Nitrogen-doped carbon shell by polydopamine coating was introduced to protect the Mn 3 O 4 /PdCu core. • Mn 3 O 4 /PdCu@NC catalyst exhibited outstanding catalytic performance compared to Mn 3 O 4 /PdM@NC (M = Ni, Au, Ag). • Mn 3 O 4 /PdCu@NC held over 90% catalytic efficiency for 4-NP reduction after ten successive cycles. • This catalyst was employed to rapidly treat environmental 4-NP water with good anti-interference. [ABSTRACT FROM AUTHOR]

This paper presents a review of our work concerning the recent progress in fabrications and applications of heating-induced long period fiber gratings (LPFGs). Firstly, three kinds of heating fabrication techniques based on CO2 laser, hydrogen–oxygen flame and arc discharge are demonstrated to fabricate LPFGs, i.e., standard LPFGs (SLPFGs) and helical LPFGs (HLPFGs), in different types of optical fibers such as conventional fibers, photonic crystal fibers, and photonic bandgap fibers. Secondly, the all-fiber orbital angular momentum (OAM) mode converters based on heating-induced SLPFGs and HLPFGs in different types of fibers are studied to increase the transmission capacity. Finally, the heating-induced SLPFGs and HLPFGs are investigated to develop various LPFG-based strain, pressure, torsion and biochemical sensors. [ABSTRACT FROM AUTHOR]

We propose a novel method for generating ±1-order orbital angular momentum (OAM) in long-period fiber gratings (LPFGs) by adjusting a polarization controller (PC). An LPFG, inscribed in a four-mode fiber (4MF) using a CO2 laser, was used to generate OAM±1 across a broad range of wavelengths from 1530 nm to 1630 nm. Additionally, the OAM vortex phase remained stable while the temperature increased from 23 °C to 50 °C. The LPFG, as a temperature sensor, and its temperature sensitivity was measured to be 38.6 ± 0.37 pm/°C at the resonant wavelength of 1625 nm. This design offers simple fabrication and several properties which are highly beneficial for all-fiber optical communications based on the OAM mode-division multiplexing technique. [ABSTRACT FROM AUTHOR]