A novel fiber-tip Fabry-Perot interferometer (FPI) sensor is proposed for high-sensitivity salinity measurement with low temperature crosstalk. It consists of two cascaded spherical FPIs fabricated directly at the tip of a single-mode fiber (SMF) by two-photon polymerization technology. One is an open sensing cavity that allows free entry of saline solution, the other is a solid reference cavity made of photoresist material. The spherical reflective surface is designed to effectively converge the divergent light beam from SMF, significantly enhancing energy coupling efficiency and spectral contrast compared to conventional planar counterparts. Through utilizing the optical Vernier effect (OVE), the salinity sensitivity amplification can be achieved. At the same time, the thermal effect can be well balanced via elaborate cavity length design, realizing temperature self-compensation for the overall sensor. Experimental results demonstrate that the as-fabricated salinity sensor can successfully provide salinity measurement sensitivity as high as-3.199 nm/%o with excellent linearity (R2 = 0.9987). Notably, the sensor also exhibits extremely low temperature crosstalk of only 0.021 nm/degrees C across a wide temperature range from 20 degrees C to 80 degrees C, significantly lower than that of the state of the art. Moreover, good measurement repeatability and stability have been validated, with wavelength drift less than 0.08 nm during 50 min of continuous monitoring. Considering the high sensitivity, excellent temperature stability, compact structure, and electromagnetic interference immunity advantages, this sensor is ideal for precise salinity detection in applications with significant temperature fluctuations, such as marine monitoring or saline chemical industries.

Chemical structure of a 5-membered ring ketone with a 4,5 double bond, carbonyl at C 1, and methyl and T B S O substituents at C 3. [1937238‐90‐8] C 12 H 22 O 2 Si (MW 226.39) InChI = 1S/C12H22O2Si/c1‐11(2,3)15(5,6)14‐12(4)8‐7‐10(13)9‐12/h7‐8H,9H2,1‐6H3/t12‐/m0/s1 InChIKey = XKWKWCIIAQCIIP‐LBPRGKRZSA‐N (building block used as a precursor for polysubstituted cyclopentane motif in natural product syntheses 1 ) Alternate Name: Maimone's enone. Solubility: soluble in most organic solvents such as CH 2 Cl 2 , EtOAc, hexane, THF, and diethyl ether; slightly soluble in water. Form Supplied in: clear oil. Analysis of Reagent Purity: 1 H NMR. Data: (600 MHz, CDCl 3 ) δ 7.41 (d, J = 5.6 Hz, 1 H ), 6.04 (d, J = 5.6 Hz, 1 H ), 2.53 (d, J = 18.2 Hz, 1 H ), 2.46 (d, J = 18.2 Hz, 1 H ), 1.48 (s, 3 H ), 0.84 (s, 9 H ), 0.08 (s, 3 H ), 0.07 (s, 3 H ). Preparative Methods: this reagent was prepared from commercially available ( R )‐linalool in a two‐step sequence. 2 ( R )‐linalool first undergoes a ring‐closing metathesis catalyzed by Hoveyda–Grubbs II catalyst, followed by TBS protection in the same pot. The cyclopentene is then subjected to allylic oxidation with RuCl 3 / t ‐BuOOH to give the title compound. These reactions can be conducted on a decagram scale. Purification: this compound can be purified via silica gel column chromatography (3% Et 2 O in hexanes to 18% Et 2 O in hexanes). Handling, Storage, and Precautions: this compound is stable at room temperature and can be stored under an argon atmosphere at −20 °C for many months.

To further enhance the wideband acoustic output performance of the piezoelectric MEMS speaker, a bimorph-enabled multi-mode excitation strategy is proposed. It employs a high-energy-density bimorph stack consisting of two layers of high-quality Sc0.2Al0.8N to construct the electroacoustic transduction structure. By selectively exciting higher-order resonance to provide multiple gain bands, excellent wideband acoustic performance can be achieved. Proof-of-concept experiments demonstrate that, despite a relatively small active area of 9 mm² and a driving voltage of 1 Vrms, the as-fabricated speaker effectively extends the acoustic bandwidth by utilizing multiple resonant modes. Compared to the conventional unimorph reference, it achieves a fundamentally enhanced wideband acoustic output, highlighting the inherent superiority of the bimorph configuration. When evaluated under large-signal conditions (up to 7 Vrms), the speaker demonstrates exceptional wideband output capability, maintaining a high SPL of over 100 dB across a broad frequency range from 23 Hz to 20 kHz, and exceeding 120 dB within the specific bands from 2.78 kHz to 7.30 kHz and 11.87 kHz to 20 kHz. Alongside these high output capabilities, the device maintains excellent electromechanical linearity with low total harmonic distortion (THD) across its primary operating bands. This design contributes to the development of compact and high-performance piezoelectric MEMS speakers that meet the stringent requirements of commercial Hi-Fi audio applications.

To break the self-contradiction dilemma between low Q factor and high sensitivity for further pushing the detection limit of the ultrasonic self-transceiving rangefinder, a ScAlN based bimorph piezoelectric micromachined ultrasonic transducer (PMUT) design is proposed. It consists of multiple elaborately patterned cantilevers interconnected by rigid springs. By selectively removing structural material and introducing additional micro-perforation array, the equivalent mass of the cantilevers can be reduced whilst the viscous damping can be significantly increased instead, thereby effectively lowering its Q factor. Simultaneously, by leveraging the high piezoelectric performance of 20% Sc-doped AlN, the high energy efficiency of the bimorph configuration and the large dynamic range of the cantilever design, high sensitivity can still be maintained. These combined features enable both small blind area of 129.1 mm and large detection distance of 4.25 m with −6 dB divergence angle of 174°, despite of the small active area of 0.62 mm2. Upon integration with a custom-designed horn, further extension of the detection range from 80.7 mm to 7 m with −6 dB divergence angle of 54° can be achieved. These results highlight the potential of the proposed PMUT for applications in intelligent systems such as drones and collaborative robots.

Given the pulse-echo operation mode, the vibration amplitude and the duration time of the piezoelectric micromachined ultrasonic transducer (PMUT) worked under resonance are both positively correlated with the quality factor Q. Therefore, the PMUT-based self-transceiving rangefinders have to face performance trade-off dilemma between the maximum detection distance and the minimum detection blind area. To address this challenge, a specially designed horn-shaped acoustic package is integrated into a quasi-closed PMUT with inherently low Q factor. A lumped-parameter acoustic model and finite element modeling (FEM) method are used for analysis, through which effective enhancement of both of the transmitting and receiving sensitivities of the PMUT can be achieved by optimizing the horn configuration. At the same time, the low Q characteristic can be well maintained, enabling simultaneous detection distance extension and detection blind area reduction. From proof of concept experiment, it can be seen that after the integration of the horn structure, the emission sensitivity and the pulse-echo signal strength of the PMUT can be increased by factors of 2.65 and 7.68, respectively, with a slight decrease in Q factor. As a result, a large detection range covering from 142.9 mm to 6 m with a -6 dB divergence angle of 66 degrees has been successfully demonstrated with a single PMUT driven by a pulsed sinusoidal signal with 72.9 kHz and 40 Vpp, despite its small effective device area of only 0.59 mm2. Provided this competitive performance, the current method possesses excellent application perspective in aircoupled ultrasonic sensing applications.

Direct glucose alkaline fuel cell (DGAFC) is an efficient energy conversion device that can oxidize the glucose in alkaline electrolytes. The nanosized DGAFC meets well with the desire for non-drug hypoglycemic in the safe treatment of diabetes while a novel catalyst could work in a blood environment. The novel glucose catalyst Cu2O/LTA (Cu2O/Linda A structured zeolite) is designed in the blood sugar environment and as-synthesized in a one-pot reaction under hydrothermal conditions. The Cu2O nanoparticles are generated, dispersed, and restricted in the nanosized opening windows of rigid zeolitic pore channels. The nano-size Cu2O/LTA presents high electrocatalytical activity with a Tafel slope of 125.56 mV dec-1, a current density of 29.39 mA cm-2 and a power density of 411.5 W m-2. The nano-size Cu2O/LTA GCE retains about 98.3 % of its initial current density after the 12-h durability test, which is higher than noble metal glucose catalysts and conventional commercial Pt/C. This excellent glucose oxidation performance is attributed to the synergistic effects of the LTA-structured zeolite nanoscale carrier and the expanded nanoscale Cu2O particles. This work supplies some inspiration for non-drug hypoglycemic with commercially available, easily prepared, non-precious metal nano-catalysts.

A novel piezoelectric MEMS speaker design based on Scandium-doped Aluminum Nitride (ScAlN) for in-ear application scenario is presented. It consists of six triangular cantilever beams with the same area, which are arranged into a hexagon shape, acting as the active electro-acoustic transduction structure. Their boundary conditions can be flexibly designed according to different requirements by controlling the etching pattern during the cantilever fabrication. As a result, the speaker can demonstrate multi resonant frequencies within the audible range. Through combining this frequency superposition design with particular actuation strategy, the output sound pressure level (SPL) of the speaker can be effectively enhanced whilst still maintaining compact device footprint without introducing additional process complexity. Moreover, a selective sealing treatment is used to solve the additional air leakage as well as the resultant SPL reduction at low frequency induced by the etching pattern. For proof-of-concept demonstration, these cantilevers with side length of 1.5 mm are intentionally designed into three groups and their resonant frequencies are measured to be 6.82 kHz, 8.06 kHz and 15.52 kHz, respectively. Despite of its small effective working area of only 5.85 mm2 and non-optimized structure design, the as-fabricated speaker device can provide SPL exceeding 70 dB and 95 dB within frequency band above 65 Hz and 5.6 kHz, respectively, under driving voltage of 7 Vrms, while the total harmonic distortion (THD) at 1 kHz can be kept at low level of only 0.77 % at the driving voltage as high as 14 Vrms.

In this study, Co2NiO4 with a tunable and hierarchical distribution of oxygen vacancies was synthesized via Ce doping and NaBH4 reduction to enhance its electrochemical performance. Ce doping through a hydrothermal method gave rise to lattice distortions and uniform oxygen vacancies at asymmetric sites, thereby improving the mobility and concentration of carriers within Co2NiO4. Moreover, the NaBH4 reduction process brought about a considerable number of oxygen vacancies and surface-active sites, both of which contributed to the increased conductivity and specific capacitance. Characterization results indicated that the Ce/Co2NiO4-Vo nanosheets with surface burrs exhibited an abundant distribution of oxygen vacancies, resulting in a boost of the material's specific capacitance while ensuring stability. At a 1 A g(-1) current density, these nanosheets achieved a maximum specific capacitance of 1493.6 F g(-1). When tested at 10 A g(-1), Ce/Co2NiO4-Vo retained 88.47% of its initial capacitance after undergoing 5000 cycles. The synthesized Ce/Co2NiO4-Vo was further combined with activated carbon (AC) to form an asymmetric supercapacitor configuration known as Ce/Co2NiO4-Vo//AC, attaining an 80.51 Wh kg(-1) energy density at 800 W kg(-1) power density. This study provides innovative strategies and highlights advancements in the high-performance supercapacitors and energy storage solutions.

The catalytic conversion of nitrogen oxides (NOx) to non-toxic products has emerged as a critical strategy for air pollution control under stringent emission regulations. Photocatalytic NOx removal performance highly depends on the transmission of photogenerated electrons and the amount of reactive oxygen species (ROS) generated. Herein, the Bi/BiOCl/SrTiO3 heterostructure photocatalyst was prepared by a simple in situ synthesis method to address the limitations of conventional NOx removal systems. Due to the synergistic effect of bismuth (Bi) surface plasmon resonance (SPR) and the built-in electric field in BiOCl/SrTiO3 S-scheme heterojunction, Bi/BiOCl/SrTiO3 showed strong light absorption ability and high charge separation efficiency, with the highest NO removal efficiency reaching 70 %. The enhanced electronic interaction between Bi and BiOCl/SrTiO3 induced Bi-O covalent bonds with the BiOCl layer to facilitate fast charge separation, promoting the rapid transfer of interfacial photogenerated carriers, this process induces the activation of O2 and H2O to form reactive oxygen species (ROS) to promote the oxidative removal of NO. This study provides new insights into the development of effective photocatalysts with fast charge separation by synergistic metal active sites and built-in electric field of heterojunction for air pollutant purification.

Traditional piezoelectric MEMS speakers that work based on exciting the first-order mode resonance of its electro-acoustic transduction structure have to face challenge in achieving broadband high sound pressure level (SPL) output performance. To address this critical issue, a novel structure design strategy by selectively exciting additional high-order resonance with net air volume pushing characteristic in the transduction structure is presented. Under the effect of resonance amplification, the broadband SPL output capability of the speaker can be effectively enhanced without compromising the compact device size. In proof-of-concept experiment, a Scandium-doped Aluminum Nitride (ScAlN) based piezoelectric MEMS speaker consisting of four identical triangular cantilever beam-like piezoelectric actuators that are arranged into a square configuration is used. Through elaborately designing the cantilever beam structure and the top electrode partition as well as corresponding driving strategy, both of its first-order (4.05 kHz) and the third-order (17.83 kHz) resonance modes can be specifically activated to cover relatively wide frequency range. From the SPL spectrum measurement results using the IEC ear simulator, it can be seen that the as-fabricated speaker prototype can successfully generate SPL higher than 90 dB over the whole audio frequency range. Especially for frequency above 65 Hz, even higher SPL of 100 dB can be achieved, under driving voltage of 20 Vpp despite of its compact active area of 3.2 x 3.2 mm2. Moreover, excellent operation linearity has also been revealed even the driving voltage is increased to as high as 30 Vpp and the total harmonic distortion (THD) as low as 0.52 % at 1 kHz (108 dB SPL) can be obtained. Given the competitive wideband performance, the proposed strategy demonstrates potential application perspective in developing piezoelectric MEMS speaker to meet commercial requirements.

Hydroxychloroquine (HCQ) residues in food and environmental water pose significant health risks to organisms, necessitating simple, on-site detection methods for home use. This study aims to develop a visual fluorescent biosensor for rapid, ultra-trace HCQ detection using smartphone-assisted visualization. Ni-doped MCM-41 mesoporous nanoparticles (Ni-MCM-41) were synthesized via a hydrothermal method, featuring an aluminosilicate core with dispersed Ni atoms and a silicated MCM-41 shell. The biosensor leverages aggregation-induced emission (AIE) to enhance HCQ fluorescence through strong host-guest adsorption. For detection, a droplet of sample is mixed with Ni-MCM-41; under UV irradiation, blue-purple fluorescence indicates HCQ presence, with intensity correlating to concentration. Smartphone color recognition software enables quantitative analysis. Results demonstrate a linear detection range of 10-7 to 10-3 M, a limit of detection (LOD) of ca. 10-9 M for visual detection, and 0.30 mu M for fluorescence spectroscopy, with high selectivity, stability, and recovery rates (97.74-107.10 %) in real samples like seawater and honey. This work introduces a low-cost, efficient homebased HCQ detection platform and provides new insights into AIE mechanisms in Ni-MCM-41-host systems.

Despite of good performance immunity to stress and high transmitting/receiving sensitivity advantages, the fabrication imperfection induced asynchronous vibration and the resultant prolonged ring-down tail severely limit the potential of the cantilever beam-based piezoelectric micromachined ultrasonic transducer (PMUT) in pulse-echo applications as transceiver. To address this issue, a novel post processing soft interconnecting strategy is presented. In this case, specific reservoir structure is intentionally integrated into the cantilever-beam based PMUT design, under the assistance of which the liquid PDMS can be accurately applied and spontaneously driven to seal the air gaps between the already released cantilever beams via the capillary effect. After curing, the PDMS will be transformed from liquid to solid and serve as soft interconnecting spring between adjacent cantilever beams so as to force them to vibrate in synchronous mode. At the same time, this treatment does not change the existing fabrication process and has little effect on the original PMUT performance. From both of the mechanical and acoustic response measurement results, effective suppression for the asynchronous vibration and significant reduction of the ring-down tail have been successfully demonstrated for the treated PMUT device. In the subsequent pulse-echo rangefinding experiment, a distance detection range covering from 270.8 mm to 3.8 m with a divergence angle close to 170° has been achieved when it is driven at resonant frequency of 69.2 kHz with 40 Vpp, 40-cycles sinusoidal signal. Given the simple yet effective treatment, the proposed strategy shows great prospective in developing high performance PMUT for in-air rangefinding applications.

PCN-222@V In -ZnIn 2 S 4 core–shell Z-scheme heterostructure containing indium defects is fabricated via solvothermal method, and it shows excellent photocatalytic degradation of tetracycline and hydrolytic hydrogen production.

Three hydrophobic porphyrin titanium-based metal-organic frameworks (MOFs) (HPA/DGIST-1, DPA/DGIST-1, and OPA/DGIST-1) were synthesized through a postsynthetic coordination reaction by using alkylphosphonic acid of different lengths (HPA, hexylphosphonic acid; DPA, dodecylphosphonic acid; OPA, octadecylphosphonic acid). Compared with the hydrophilic DGIST-1, modified DGIST-1 exhibits excellent hydrophobicity and presents good stability in humid atmospheres. Due to the introduction of porphyrin ligands, HPA/DGIST-1, DPA/DGIST-1, and OPA/DGIST-1 showed good visible-light absorption (380-700 nm) and sensitive photogenerated charge responses. When acted as catalysts, these hydrophobic Ti-MOFs can selectively reduce CO2 to HCOO- under visible-light irradiation with average reaction rates of 150.9, 178.5, and 228.3 mu molh(-1)g(-1), where these values are 1.3-2.0 times higher than the system mediated by the initial porphyrin Ti-MOF catalyst. C-13 NMR spectroscopy demonstrates that the catalytic product HCOO- anion originates from the reactant CO2. The photocatalytic experiments, electron paramagnetic resonance, and photoluminescence spectra tests showed that porphyrin ligands and Ti-O units can act as catalytic activity centers to realize the conversion of CO2 to HCOO-. This work demonstrated that the combination of porphyrin titanium-based MOF and alkyl hydrophobic groups is an effective way to enhance the stability of titanium-based MOFs and maintain their high photocatalytic performance.

For glucose sensors, improved sensitivity, accuracy, stability and convenience have always been desired. A novel sensing platform combining CuxO (x = 1, 2) nanoparticles and LTA-structured zeolite well fulfills these requirements and achieves breakthrough sensing concentration (6.0 x 10(-15) M). In hydrothermal conditions, highly dispersed CuxO nanoparticles are formed and restrined in the nano-opening windows of the zeolite surface pores, ultimately yielding CuxO LTA. These in situ-synthesized CuxO NPs have high catalytic activity, while the zeolite provides a stable and rigid framework. This sensor has good selectivity and sensitivity (1.45 mu A mu M-1 cm(-2)) for the determination of glucose under physiological conditions (pH = 7.4) using the DPV method with a limit of detection (LOD) as low as 6.0 x 10(-15) M. The amperometry method exhibited a fast response time of only 0.1 s under strong alkaline conditions (1.0 M NaOH) and achieved a sensitivity of 6.94 mu A mu M-1 cm(-2) and LOD of 2.0 x 10(-9) M. This advanced hybrid sensor system not only provides a wide range of application environments, but also has important implications for the development of low-cost, stable, fast, and efficient non-enzymatic glucose sensors for noble metals. The theoretical support of density-functional theory (DFT) affirms the interaction between zeolite fine structure and glucose molecules.

Three dye-loaded tunable dual-emission colorimetric fluorescent probes RhB@UiO-66-Ph (R@U-P) were prepared by in-situ encapsulation method under solvothermal conditions. The resonance energy transfer between UiO-66-Ph and RhB made the dual emission of R@U-P easily tunable with the embedded dye content changing. The R@U-P composites achieved emission from purple light to red light, and served as probes to realize comparative detection of Fe3+, Fe2+ and Cr2O72- in water through colorimetric or quenching detection mode. Mechanism study indicates that the resonance energy transfer or electron transfer interactions between R@U-P composites and inorganic ions resulted in the relative changes of the two emission peaks and realized the selective detection of analytes. The preparation and application of R@U-P probes provide a promising strategy for the in-situ encapsulation dye to obtain two dual-emission composites for the comparative detection of Fe3+, Fe2+ and Cr2O72- in water samples.

Peroxymonosulfate (PMS) could be activated by either radical path or non-radical path, how to rationally mediate these two routines was an important unresolved issue. This work has introduced a simple way to address this problem via metal atom doping. It was found that Fe-doped nitrogen-rich graphitic carbon nitride (Fe-C3N5) exhibited high activity towards PMS activation for tetracycline degradation, and the degradation rate was 3.14 times higher than that of Co-doped nitrogen-rich graphitic carbon nitride (Co-C3N5). Radical trapping experiment revealed the contributions of reactive species over two catalysts were different. Electron paramagnetic resonance analysis further uncovered the non-radical activation path played a dominated role on Fe-C3N5 surface, while the radical activation path was the main routine on Co-C3N5 surface. Density functional theory calculations, X-ray photoelectron spectroscopy analysis, and electrochemical experiments provided convincing evidence to support these views. This study supplied a novel method to mediate PMS activation path via changing the doped metal atom in g-C3N5 skeleton, and it allowed us to better optimize the PMS activation efficiency.

A quasi-static multi-degree-of-freedom piezoelectric MEMS micromirror with large mirror plate and high fill factor based on AlScN is presented. It consists of two individual components, namely the mirror plate and the actuator. They are fabricated separately and vertically assembled together to form the final combination. In current case, a square mirror plate with side length of 5 mm is used. The actuator is designed into a gimbal-less structure, which involves a central connection platform with a mounting hole and four groups of piezoelectric actuators that are connected to the platform's corners via serpentine springs. This configuration provides multi-degree-of-freedom driving capabilities, allowing tip-tilt-piston mirror movement. The piezoelectric actuator is composed of three-stage cantilever-type actuation units that are connected in series, and they are intentionally arranged into S-shape so as to be completely hidden beneath the mirror plate. Moreover, the driving performance is further improved by optimizing the electrode coverage region on each actuation unit. As a result, not only large displacement but also nearly 100 % fill factor as well as high optical utilization efficiency can be achieved. From experimental results, the as-fabricated MEMS micromirror demonstrates static mechanical tilt angles of approximately +/- 2.2 degrees about two orthogonal axes and piston vertical movement of +/- 54.9 mu m within +/- 50 V-DC driving voltage range with excellent linearity. Given the large mirror size, high fill factor and multi-degree-of-freedom motion advantages, the proposed micromirror could be found application perspective in light field shaping, free space optical communication and projection lithography areas.

To improve the performance of the Piezoelectric Micromachined Ultrasonic Transducer (PMUT) based rangefinder and decrease its stress sensitivity, a novel design with quasi-closed structure is proposed. It adopts a circular piezoelectric composite diaphragm structure with clamped boundary, in which all the deposited stack layers in its central region are intentionally removed and additional cross-slits are created into the remaining silicon device layer. Due to the reduced mass and the enhanced thermal-viscous damping at slits, a 35.2 % decrease in quality factor Q has been achieved in the proposed PMUT when compared with the conventional design, resulting in a distinctly reduced blind area from 231.3 mm to 170.7 mm. At the same time, the proposed quasi-closed PMUT facilitates the release of accumulated stress in the device structure during fabrication and operation. As a result, an approximate 50 % reduction in frequency deviation between different as-fabricated PMUTs across the same wafer has been successfully obtained. Moreover, due to the increased linear operation range, the developed bare PMUT chip demonstrates a maximum detection distance of 3 m at the operation frequency of 71.5 kHz under 40 V pp driving voltage. Given the advantages of lower Q , insensitivity to stress, good fabrication consistency and large linear operation range, the proposed quasi-closed PMUT design can well address the requirements on small blind area and large detection range for distance sensing applications.