Mitochondria are essential organelles that play pivotal roles in cellular energy metabolism, signaling, and homeostasis, and their dysfunction is closely associated with various human diseases. In recent years, the rapid development of mitochondria-targeted fluorescent probes has greatly expanded our ability to visualize mitochondrial structure and monitor diverse physicochemical and biochemical parameters in situ. While existing reviews have primarily categorized these probes by specific physiological readouts, a unified perspective that integrates probe design strategies, fluorophore engineering, and target physiological parameters is stilling lacking. To address this gap, we provide a systematic overview of mitochondrial fluorescent probes, focusing on molecular design principles, fluorophore selection, targeting strategies, and the sensing of key mitochondrial physiological indices. In addition, we critically discuss current limitations and emerging challenges, and outline future directions in this field. This review aims to offer theoretical insights and practical guidance for the rational design of mitochondrial fluorescent probes, promoting their broader applications in life science and biomedical research.

The effects of F doping concentration on the electronic structure and transport properties of SnO2 were systematically investigated using density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) method. The results show that F doping effectively modulates the electronic structure of SnO2, with the band gap decreasing from 2.56 eV for pristine SnO2 to 1.96 eV at 8.33% F doping, indicating enhanced n-type characteristics. Charge density and Bader charge analyses reveal that F substitution induces significant charge redistribution and enhances charge transfer within the lattice. Electronic transport calculations demonstrate that moderate F doping increases the density of states and transmission probability near the Fermi level, resulting in improved conductance and current response. In contrast, excessive F doping suppresses electron transmission and deteriorates transport performance. Real-space transmission-eigenchannel and inverse participation ratio analyses further indicate that this transport suppression is accompanied by enhanced localization of the dominant transport channel at high F concentrations. Among all investigated structures, the Au-SnO2-Au device with approximately 7.50% F doping exhibits the highest conductance and the most favorable transport characteristics under the present computational model. These findings demonstrate that F doping is an effective strategy for tuning the electronic structure and transport behavior of SnO2 and provide theoretical guidance for the design and optimization of high-performance SnO2-based electronic and optoelectronic devices.

Mitochondria are central regulators of cellular energy metabolism, redox balance, and signal transduction, and fluorescent probes have become indispensable tools for visualizing their structure and function with high spatial and temporal precision. Because mitochondrial physiological parameters, including membrane potential, pH, viscosity, reactive species, and ion fluxes, arise from distinct microenvironmental features, their accurate detection requires probe designs based on different photophysical mechanisms. Although several reviews have summarized probes for specific mitochondrial indicators, systematic discussions focused on the underlying photophysical design mechanisms remain scarce. In this review, we comprehensively summarize the major mechanisms that govern mitochondrial probe performance, including photoinduced electron transfer (PET), intramolecular charge transfer (ICT), Förster resonance energy transfer (FRET), aggregation-induced emission (AIE), and excited-state intramolecular proton transfer (ESIPT). Particular emphasis is placed on their design principles, analytical characteristics, representative applications, and inherent advantages and limitations from a bioanalytical perspective. It is respected that this mechanism-oriented review will provide useful guidance for the rational development of next-generation mitochondrial fluorescent probes for precise imaging and sensing.

Flexocatalysis has garnered considerable attention due to its capability to capture and convert dispersed mechanical energy into chemical energy, and this mechanism is universally applicable to all dielectric materials. Nevertheless, research on flexocatalysis was still in its early stages, and the catalytic efficiency remains unsatisfactory. Herein, a novel flexocatalyst MnB4O7 (MBO) with excellent catalytic performance was successfully synthesized via the high-temperature solid-state reaction method. Under ultrasonic oscillation, MBO achieved a TC degradation efficiency of 91.2 % within 6 min, whereas it reached 90.5 % within 50 min under magnetic stirring. According to the results of in-suit EPR and XPS, the concentration of surface oxygen vacancies (Ov) increased from 11.28 % in the untreated MBO sample to 16.98 % and 21.27 % during the magnetic stirring and ultrasonic oscillation reaction processes, respectively, indicating that more Ov were in-situ generated on the material surface under mechanical force. Compared with conventional magnetic stirring, high-intensity ultrasonic oscillation led to a higher concentration of Ov and stronger flexoelectric polarization effect in the MBO sample, thereby endowing MBO with superior flexocatalytic performance. The stronger flexoelectric polarization effect provides a more substantial driving force for charge carrier separation during the MBO catalytic process. Meanwhile, density functional theory (DFT) calculations demonstrated that Ov can regulate the electronic structure of MBO materials, reducing the adsorption energy of MBO samples on TC from - 0.59 eV to - 0.70 eV, and shifting the center of the p-band away from the Fermi level, decreasing from - 1.71 eV to - 1.81 eV, which enhances the charge transport capability of MBO. Those optimizations significantly improves the flexocatalytic performance of MBO materials. This study proposes a novel flexocatalytic material and elucidates the enhanced mechanism of catalytic activity by in-situ oxygen vacancies and flexoelectric polarization effect formed under mechanical force, which holds significant implications for advancing the theoretical advancement of flexocatalysis and promoting its practical applications.

In materials lacking spatial inversion symmetry, the photovoltaic generation effect (PGE) manifests under polarized irradiation without the necessity of a p-n junction and demonstrates high polarization sensitivity across a broad spectrum. This characteristic presents significant potential for applications in low-power two-dimensional optoelectronic devices. In this study, we investigate the electronic structure, optical properties, and PGE in 2H-TiS2 by first-principles simulations, incorporating various types of point defects. We propose a mechanism to enhance photoconductivity in 2H-TiS2 by substitution doping and vacancy defects. When the photodetector is aligned along the armchair direction, the photocurrent exhibits a cosine dependency on the linear polarization angle. We achieved a remarkable enhancement in photocurrent, with a maximum value of 1.33 a20/photon, in contrast to only 0.11 a20/photon for the pure membrane. This improvement can be attributed to the introduction of point defects, which diminish the symmetry of the device and increase its asymmetry, thereby enhancing the photocurrent. Furthermore, we attained high polarization sensitivity, evidenced by a maximum extinction ratio of 262.4. Our findings not only propose an effective mechanism for enhancing PGE by substitution doping but also underscore the promising applications of the two-dimensional 2H-TiS2 monolayer in optoelectronics, particularly in photoelectric detection.

Take advantage of the 4f electron transition of Er ions and two-dimensional nanosheets, four kinds of ErBO3 powders with different morphologies were prepared by hydrothermal method and their photocatalytic degradation performance of Norfloxacin were investigated. XRD and SEM results indicate that all four prepared products are single-phase ErBO3 compounds, exhibiting distinct microstructural morphologies. Among them, the ErBO3(8) flower self-assembled by two-dimensional nanosheets exhibits the highest photocatalytic performance and the degradation rate of norfloxacin can reach 89.6 % after 120 min illumination, and the first-order rate constant is 1.04 x 10-2 min-1. Through the comparative analysis of the four powders' properties, it was found that ErBO3(8) flower balls had the lowest fluorescence intensity and the highest photocurrent, which indicated that the material exhibits a high efficiency in separating photogenerated carriers. This can primarily be attributed to its unique nanosheet structure, which not only confers a high specific surface area but also significantly increases the concentration of chemisorbed oxygen, thereby effectively suppressing the recombination of photogenerated carriers.

Although k-means and its variants are known for their remarkable efficiency, they suffer from a strong dependence on the prior knowledge of K and the assumption of a circle-like pattern, which can result in the algorithms dividing the input space instead of discovering non-predetermined data patterns. Thus, we propose beyond k-means++ that infers and utilizes explicit clusters by emphasizing local geometrical information for better cluster exploration. To avoid the K dependence, a novel framework of iterative division and aggregation (IDA) over k-means++ is presented. It begins with any K≥1, then increases and reduces K along with the procedure of clusters' division and aggregation, respectively. To break through the circle-like pattern limitation, we introduce a reasonability checking strategy (RCS) for cluster division. Given local geometrical information, RCS achieves arbitrary cluster shape support by rejecting edge patterns with distinguished convergence direction and merging adjacent clusters with pseudo-edge patterns. Furthermore, we design an edge shrinkage strategy (ESS). Taking edge patterns as the cluster prototype, it benefits accuracy by effectively avoiding representability reduction due to irregular distribution. To compensate for the loss of efficiency, a near maximin and random sampling algorithm is suggested for large-scale data with high dimensionality. Experimental results confirm that beyond k-means++ is featured by handling arbitrary cluster shapes with remarkable accuracy.

A new rare earth borate photocatalytic material ErBO3 has been successfully prepared by hydrothermal method. Due to the particularities of f–f electron transition of Er3+ ion, ErBO3 becomes a visible light responsive photocatalytic material. ErBO3 exhibits certain photodegradation ability to RhB molecules. Then, a series of GO@ErBO3 composites were prepared by using GO as a co-catalyst. The properties of samples were characterized using XRD, FE-SEM, XPS, FT-IR, Raman, and BET methods. Through detection analysis, it was found that the combination of GO could improve the visible light absorption performance, the specific surface area and the photogenerated carrier separation efficiency of ErBO3 material, and then the visible light responsive photocatalytic material 0.5 wt

The efficient photogenerated carriers separation is the key factor in enhancing the activity of photocatalysts to solve environmental pollution problems. The internal polarized electric fields in polar materials most likely provide a more direct and stronger driving force for photogenerated carriers separation. Here, we investigate polar ε-Cd(IO3)2 (CIO) with two different morphologies as an efficient photocatalyst for the photodegradation of antibiotics and dyes. According to the theoretical calculation of the ratios of mh*/me* along three different crystal axis directions, the photogenerated carrier separation efficiency along the c-axis direction is the largest, which matches the direction of the polarized electric field in the crystal. The internal polarized electric field promotes the separation of photogenerated carriers, leading to a high transfer efficiency of the catalyst. Moreover, photodegradation experiments demonstrate that the photocatalytic activity of CIO-1 is approximately 3 times that of TiO2 P25. This study provides some insights that might aid the development of polar photocatalysts with superior performance.

目的 提高金属/陶瓷体系高温固体润滑耐磨涂层的抗氧化性能.方法 采用离心喷雾造粒、高压氢还原镀镍和固相合金化技术,制备包覆型NiCoCrAlY/Al2O3-10％B4C复合粉体,并采用超音速火焰喷涂技术在镍基高温合金上沉积复合涂层材料,通过SEM和XRD研究粉体和涂层的显微结构和物相组成,通过马弗炉研究涂层在高温下的氧化性能.结果 Al2O3-B4C颗粒表面均匀包覆着一层厚度为2～3μm的NiCoCrAlY合金.超音速火焰喷涂NiCoCrAlY/Al2O3-10％B4C复合涂层结构致密,孔隙率仅为0.45％±0.05％,涂层与基体结合良好.涂层和粉体的主晶相均为Ni的固溶体、α-Al2O3相和B4C相,涂层衍射峰强度比粉体有所降低.在850℃氧化96 h后,涂层表面生成了一层连续的灰色物质,其厚度为1～3μm,经EDX分析,其主要元素组成为O、Ni、Al和Cr,说明主要成分为Ni、Al和Cr的金属氧化物.涂层在850℃的氧化动力学曲线分为2个阶段,氧化初期,涂层快速氧化,生成以NiO、Al2O3和Cr2O3为主的混合氧化物膜;氧化后期,涂层进入稳定氧化阶段,此时涂层的氧化过程主要由O在氧化膜中的扩散速度决定.结论 涂层在850℃的抗氧化性能良好,可在850℃的氧化环境下使用.

The crystal structure of Ba2-xMgB2O6:xEu3+ phosphors, synthesized using a solid-state reaction, have been confirmed by X-ray diffraction analysis. This study focuses on the site occupancy preference of Eu3+ ions within the matrix, which was determined using bond energy theory, fluorescent spectra, and a consideration of energy transport and decay curves. The impact of Eu3+ ion concentration on luminescence has been assessed, and an optimal concentration (x = 0.22) identified. The critical distance, Rc was 9.6 angstrom, with a calculated theta value of 19.67, indicating that quadrupole-quadrupole interaction plays a critical role in the quenching Ba2-xMgB2O6: xEu3+ phosphors. The Ba2-xMgB2O6:xEu3+ phosphors exhibited a color purity of 99.26%, and a quantum efficiency of 49.68%. The activation energy Ea was determined to equal 0.2987 eV. The results have established Ba1.78MgB2O6:0.22Eu3+ as a red fluorescent powder with high quantum efficiency and a millisecond fluorescence lifetime.

Three kinds of EuBO3 photocatalysts with different morphological characteristics were successfully synthesized using a facile hydrothermal method. The crystal structure, surface chemical composition, and micromorphology features of the EuBO3 photocatalysts were measured using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and BET-specific surface area measuring methods. The optical characteristics of all synthesized photocatalysts were described in detail by ultraviolet-visible spectroscopy and photoluminescence spectroscopy measurements. The photocatalytic activity of all synthesized photocatalysts in the photodegradation of RhB under UV-light irradiation (λ > 254 nm) was determined. The EuBO3(9) catalyst showed the highest photocatalytic activity among three kinds of photocatalysts with different morphologies. The enhanced photocatalytic activity of the EuBO3(9) photocatalyst is primarily attributed to the higher specific surface area than the other samples. Meanwhile, a possible mechanism for photocatalytic degradation was proposed.

In Brain Computer interface (BCI) system, motor imagination has some problems, such as difficulty in extracting EEG signal features, low accuracy of classification and recognition, long training time and gradient saturation in feature classification based on traditional deep neural network, etc. In this paper, a deep belief network (DBN) model is proposed. Fast Fourier transform (FFT) and wavelet transform (WT) combined with deep machine learning model DBN were used to extract the feature vectors of time-frequency signals of different leads, superposition and average them, and then perform classification experiments. The number of DBN network layers and the number of neurons in each layer were determined by iteration. Through the reverse fine-tuning, the optimal weight coefficient W and the paranoid term B are determined layer by layer, and the training and optimization problems of deep neural networks are solved. In this paper, a motion imagination and Motion observation (MI-AO) experiment is designed, which can be obtained by comparing with the public dataset BCI Competition IV 2a. The DBN model is used to compare with other algorithms, and the average accuracy of binary classification is 83.81%, and the average accuracy of four classification is 80.77%.

为评估排气后处理系统中混合器的性能,利用计算流体力学(CFD)耦合尿素分解详细机理建立柴油机排气后处理系统的三维数值模型.基于该模型计算尿素水溶液的蒸发和热解产物包括3种尿素分解副产物(缩二脲、三聚氰酸和三聚氰酸一酰胺)的形成过程,并利用尿素结晶和副产物的质量与分布、选择性催化还原(SCR)入口均匀性以及混合器前后压力差等指标评价两个不同结构混合器的性能.其中混合器1前后及底部各布置一块挡板,混合器2顶部布置旋流叶片.结果表明:湍流强度小且分布均匀的系统(如混合器1)尿素结晶质量多而液膜和副产物质量少,尿素结晶、液膜和副产物主要分布在混合器;局部湍流强度大且分布不均匀的系统(如混合器2)尿素结晶质量少而液膜和副产物质量多,尿素结晶和液膜分布在混合管和混合器,而副产物主要分布在混合管;混合器1的SCR入口 NH3均匀性好于混合器2,其前后压力差也小于混合器2.

NaBa12B7O21F4:xEu(3+) phosphors, where 0 < x <= 0.16, were obtained through the high temperature solid phase reaction method. The phosphors showed significant red fluorescence emission resulting from the dominant D-5(0)-> F-7(2) transitions. The optimum doping concentration of Eu3+ ions in the NaBa(12)B(7)O(21)F(4 & nbsp;)matrix were estimated to be 14 mol%. The phenomenon of concentration quenching was researched, and the concentration quenching of NaBa12B7O21F4:xEu(3+) phosphors maybe caused by the exchanging interaction of Eu3+ ions. Moreover, it was found that the optimal-component NaBa12B7O21F4:xEu(3+) phosphor showed high absolute luminescence quantum efficiency and had a millisecond fluorescence lifetime.

采用高温固相反应法制备了一系列镝离子掺杂Bi2ZnB2O7(BZBO)光催化剂.通过XRD、TEM和HRTEM等手段对BZBO:xDy3+材料的结构及形貌等进行了表征,通过RhB溶液在紫外灯下的光降解实验研究了不同浓度镝离子掺杂对BZBO光催化性能的影响.RhB光降解实验结果表明,当Dy3+在BZBO中的掺杂量为4％时,BZBO:4％Dy3+具有最好的光降解活性,其光降解活性为纯BZBO的1.56倍.通过光吸收性能分析可知,Dy3+的引入增强了BZBO的紫外吸收强度,并稍降低了其禁带宽度.光吸收性能、光致发光光谱、光电流和EIS实验结果表明,BZBO:4％Dy3+的光催化活性增强的主要原因是BZBO中掺杂的镝不仅提高了BZBO光催化剂的光吸收能力,更促进了光生电子-空穴对的分离和转移.因此,在稀土元素和极化电场的作用下,BZBO:4％Dy3+的光催化活性要高于其他所制备的样品.