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Online quantitative analysis of the reaction gas or tail gas of industrial production process can help to adjust the production process and improve product quality in time, which is of great significance to the transformation and upgrading of the relevant industries. However, due to the influence of industrial production cost, the application of expensive high-resolution mass spectrometer in industrial online quantitative analysis is relatively limited, while low-resolution mass spectrometer may detect the mass spectra with overlapping peaks, causing difficulties in the accurate quantification of reaction or tail gases. Although the current online quantitative analysis methods are relatively mature, there are still some spaces for optimization in terms of quantitative accuracy, method applicability and equipment complexity. For more accurate and more efficient online quantitative analysis, an online process mass spectrometer was proposed to detect the reaction gas or tail gas and separate the overlapping spectral peaks. At first, the component gases and their corresponding contents of the reaction gas or tail gas under measurement were accurately predicted according to industrial production scenarios, obtaining a prediction matrix and formulating a calibration standard gas. Secondly, all the overlapping spectral peaks of the calibration standard gas were obtained through finding the standard mass spectra of each component gas, and the simplest ratio matrix was constructed according to its relationship with the main peaks of each component gas, which was corrected by formulating the ratio standard gases with the same content as the relevant component gases. Then, the calibration matrix was obtained through detecting and calculating the calibration standard gas with the mass spectrometer, together with the prediction matrix and the ratio matrix, the calibration mathematical model was constructed to obtain the relative sensitivity matrix. Finally, a quantitative mathematical model was constructed with the calculated relative sensitivity matrix, the corrected ratio matrix and the detection matrix obtained after detecting and calculating the reaction gas or tail gas under measurement, and the content matrix of each component gas was obtained to monitor and control the industrial production process in real time. The online quantitative analysis of representative yeast fermenter tail gas showed that the method has high accuracy and strong applicability. After several rounds of online quantitative analysis experiments, the maximum quantitative error could be controlled within 0.4%, and the maximum quantitative relative standard deviation could be limited within 2%.

The Nantong Ancient Ship refers to an ancient Chinese wooden ship of the late Ming Dynasty excavated in Nantong city in December 2022. This paper identifies the wood and discusses its related analysis. Wood samples extracted from the Nantong Ancient Ship were studied from the viewpoints of anatomy, physics, and chemistry. Microscopic identification results concluded that willow and Chinese fir were the main wood species used to make this ship. The content of holocellulose in the ancient wood was only 37.9 to 38.9%, while the content of lignin was 55.2 to 56.4%. The cellulose crystallinity of ancient wood was 39 to 42% lower than that of healthy recent wood. Fourier transform infrared (FTIR) spectra revealed that the deterioration of ancient wood caused cellulose and hemicellulose degradation, but no apparent lignin alteration. The results could provide a basis for drawing up a conservation plan for the Nantong Ancient Ship. They could also provide a reference for the research and conservation of other archaeological shipwrecks in China.

This paper presents a low-altitude unmanned aerial vehicle (UAV) attitude detection and tracking algorithm, named UAV-Pose. In the context of low-altitude UAV countermeasure tasks, precise attitude detection and tracking are crucial for achieving laser-guided precision strikes. To meet the varying requirements during the tracking stages, this study designs two capture networks with different resolutions. Firstly, a lightweight bottleneck structure, GhostNeck, is introduced to accelerate detection speed. Secondly, a significant improvement in detection accuracy is achieved by integrating an attention mechanism and SimCC loss. Additionally, a data augmentation method is proposed to adapt to attitude detection under atmospheric turbulence. A self-collected dataset, named UAV-ADT (UAV Attitude Detection and Tracking), is constructed for training and evaluating the target detection algorithm. The algorithm is deployed using the TensorRT tool and tested on the UAV-ADT dataset, demonstrating a detection speed of 300 frames per second (FPS) with a map75 reaching 97.8% and a PCK (Percentage of Correct Keypoints) metric reaching 99.3%. Real-world field experiments further validate the accurate detection and continuous tracking of UAV attitudes, providing essential support for counter-UAV operations.

Vitamin D deficiency and insufficiency is a global health issue that afflicts people of different age groups all over the world. As a reliable indicator for the evaluation of vitamin D, 25OHD is usually determined by LC-MS/MS. The tandem mass spectrometry based on ion trap has the characteristics of simple structure and high sensitivity. However, there are some problems such as narrow linear range and space charge effect, which limit its analysis of trace substances in complex matrix samples. In this study, the device and technology of a new quadrupole linear ion trap mass spectrometry was used to reduce the space charge interference of trace or ultra trace target ions by high abundance impurity ions in complex matrices. For the first time, isotope dilution mass spectrometry for accurate measurement of serum 25OHD was established by QLIT-6610MD, which is quadrupole-linear ion trap tandem mass spectrometer, and was independently developed by Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology. Serum samples were precipitated with methanol, extracted with n-hexane, dried with liquid nitrogen, redissolved in the initial mobile phase, and determined by QLIT-6610MD. The matrix-matched standard curve was used for quantification. The linear ranges of 25OHD2 and 25OHD3 were in the range of 0.78-50 μg/L and 1.56-100 μg/L with R2>0.999 9, respectively. The detection and quantification limits of 25OHD2 and 25OHD3 were 0.06, 0.12 μg/L and 0.02, 0.06 μg/L, respectively. The precision of quality control was better than 4.06%. The recoveries ranged from 99.25% to 108.38%, and the coefficients of variation were all less than 5.1%. After the method confirmation, the quantitative results of clinical samples were compared with triple quadrupole tandem mass spectrometry. 50 Clinical serum samples were measured and compared by QLIT-6610MD, AB 4500MD and YS EXACT 9900MD. The correlation and consistency of the data were analyzed by Pearson and Bland-Altman. The correlation coefficient of the three groups data was R≥0.998 0, P

Combined with mass spectrometry, ion spectroscopy can obtain a spectrum of the target ion by measuring its intensity change, which is induced by laser strength and wavelength. It integrates the high sensitivity of mass spectrometry and the structural specificity of spectroscopy, and thus proves to be very useful in structure characterization of complex biomolecules, such as proteins, peptides, glycans, oligonucleotides, etc. However, the electronic or vibrational spectra becomes too complex to be resolved when analyzing isomeric ions. Ion mobility spectrometry (IMS) allows ionized molecules to be separated on the basis of mobilities in the gas phase, and its coupling with electrospray and MALDI ion sources opens up possibilities for structural studies of a wide range of biomolecules in gas-phase. Ion mobility spectrometry coupled with mass spectrometry has seen spectacular growth for the last two decades. The introduction of ion mobility to ion spectroscopy has been of growing attention in recent years. While IMS can be used as an isomer filter to reduce spectral congestion of ions, highly resolved ion spectra facilitates the identification of the isomer peaks separated by IMS. Taken together, spectra and collision cross section (CCS) measurements on the same system prove to be rather useful for structural analysis and provide clearer spectroscopic fingerprint to isomers. Therefore, this paper briefly summarized advances in ion spectroscopy research based on ion mobility-mass spectrometry technology, introduced representative researches, and prospected possible development in multi-dimensional structural mass spectrometry.

In this paper, research was conducted on Deep Learning Wavefront Sensing (DLWS) neural networks using simulated atmospheric turbulence datasets, and a novel DLWS was proposed based on attention mechanisms and Convolutional Neural Networks (CNNs). The study encompassed both indoor experiments and kilometer-range laser transmission experiments employing DLWS. In terms of indoor experiments, data were collected and training was performed on the platform built by us. Subsequent comparative experiments with the Shack-Hartmann Wavefront Sensing (SHWS) method revealed that our DLWS model achieved accuracy on par with SHWS. For the kilometer-scale experiments, we directly applied the DLWS model obtained from the indoor platform, eliminating the need for new data collection or additional training. The DLWS predicts the wavefront from the beacon light PSF in real time and then uses it for aberration correction of the emitted laser. The results demonstrate a substantial improvement in the average peak intensity of the light spot at the target position after closed-loop correction, with a remarkable increase of 5.35 times compared to the open-loop configuration.

The existence of the double grid frequency (100 Hz) ripple current in dc/ac dual active bridge (DAB) power converters can degrade their performance and as such these ripples need to be compensated. An active power decoupling method is proposed in this paper to attenuate the 100-Hz current ripple in single phase dc/ac DAB converters. Compared to other current ripple reduction methods for which additional switches are used, the proposed method does not require any additional switching components thus decreasing the system cost. In the proposed method, the existing switching devices of the primary side full bridge converter and an LLC circuit integrated to form a 100-Hz ripple current reduction circuit, which is controlled by regulating the duty cycle of the primary full bridge converter switching legs. The mathematical analysis and the circuit parameter design methods are proposed. In addition, a current sharing method is proposed to keep the currents of the inductors in the LLC circuit are balanced against any possible circuit parameter deviations. The effectiveness of the developed method is evaluated through the simulation and experimental tests.

In traditional hybrid energy storage system (HESS), separated bidirectional dc/dc converter is usually used to interface energy storage system with dc bus. Though it has an advantage in flexibility of control system design using separated power converters, it results in more switches, auxiliary components, and cost for the whole system development. Particularly, since the energy storage system (ESS) designed for high dynamic compensation (e.g., supercapacitor) is mainly used to provide high-dynamic compensation in transient state process, the utilization rate of the corresponding interface dc/dc converter is relatively low. On the other hand, the dc bus voltage compensation performance will be discounted due to the inherent time delay for the current reference signal production of HESS with outer loop voltage control. In this paper, to address these two issues, an integrated topology of the hybrid energy storage system is proposed, and an improved control method that has the ability to enhance the control performance of HESS to compensate the dc bus voltage is developed too. The experimental test results are provided to validate the correctness and effectiveness of the proposed methods.

Input-parallel output-series (IPOS)-based combined converter is usually used in the situation with low input voltage and high output voltage to satisfy the requirements in switch voltage stress reduction and power expansion. In such a system, the voltage balance of filter capacitor in the output side or current sharing in the input side usually used to guarantee the control performance of the conversion system. In this paper, a phase-shifted full bridge (PSFB)-based IPOS converter with modified connection of output filter circuit used for the wide variation of input voltage is proposed, which is beneficial to reduce ripple current of filter inductor significantly. A control scheme using the same phase shifting for the two different modules of this IPOS converter is detailedly investigated with both steady state and small signal model-based analysis, it manifests that special voltage balance and current sharing control scheme are not necessary for IPOS system under the common phase shifting control method. And the small signal transfer functions of this topology used for dual loop control system design are also developed. The simulation and experiment results are presented to validate the analysis and control scheme.

A bidirectional integrated bus voltage conditioner (IBVC) for an isolated phase-shifted full bridge (PSFB) dc/dc converter is proposed to reduce the dc bus voltage oscillations in a cascaded power converter system, where a load converter is controlled tightly with high-control bandwidth. In the proposed method, unlike conventional dc bus voltage stabilization methods for which auxiliary switches are used, the multiplexing utilization of the full bridge switches at the primary side of a PSFB is adopted. In this paper, to improve the dc bus voltage stability, an equivalent virtual resistor is implemented by applying the duty cycle regulation for both legs of the PSFB. The effectiveness of the proposed method on the dc voltage stabilization is examined through simulations and experiments. The achieved results reveal that the dc bus voltage stability is significantly improved with the proposed method.

A heat conduction model with an arrow-shaped high thermal conductivity channel (ASHTCC) in a square heat generation body (SHGB) is established in this paper. By taking the minimum maximum temperature difference (MMTD) as the optimization goal, constructal designs of the ASHTCC are conducted based on single, two, and three degrees of freedom optimizations under the condition of fixed ASHTCC material. The outcomes illustrate that the heat conduction performance (HCP) of the SHGB is better when the structure of the ASHTCC tends to be flat. Increasing the thermal conductivity ratio and area fraction of the ASHTCC material can improve the HCP of the SHGB. In the discussed numerical examples, the MMTD obtained by three degrees of freedom optimization are reduced by 8.42% and 4.40%, respectively, compared with those obtained by single and two degrees of freedom optimizations. Therefore, three degrees of freedom optimization can further improve the HCP of the SHGB. Compared the HCPs of the SHGBs with ASHTCC and the T-shaped one, the MMTD of the former is reduced by 13.0%. Thus, the structure of the ASHTCC is proven to be superior to that of the T-shaped one. The optimization results gained in this paper have reference values for the optimal structure designs for the heat dissipations of various electronic devices.

The three-port converter (TPC) obtains major attention due to its power density and ability to dispose different electric powers flexibly. Since the control models of the TPC are derived from particular steady state work point through small signal modeling method, the model parameters usually be deviated from their normal values with the change of operation and load conditions. Furthermore, there are couplings and interactions in power delivery between different ports, which have a significant influence in the dynamic control performance of the system. In this paper, the H∞ mixed sensitivity method is employed to design robust controllers for a TPC control system. Simulation results are given to demonstrate the effectiveness of the proposed scheme, and experimental studies are conducted on a prototype circuit to further validate the developed method. Compared to a traditional PI controller, it shows that a mixed sensitivity based robust controller manifest balanced performance in model parameters changes attenuation and dynamic control performance.

Since it has strong ability to realize a conversion to adapt to a wide variation of input voltage, the double-switch buck-boost (DSBB) converter is usually employed as a front-end converter in two-stage power converter systems, where conversion efficiency is always highly valued. Because there is only one switch in the Pulse Width Modulation (PWM) state in the buck or boost work mode, the combined control scheme was investigated for its advantages in inductor average current and conversion efficiency. However, in this method, the operation mode should be determined by additional logic according to the change of input voltage. Moreover, different control systems should be designed for different operation modes to guarantee dynamic control performance and smooth transition between different work modes. To address these issues, the linear active disturbance rejection control (LADRC) method is introduced to develop an inner current control loop in this paper. In this method, the model deviations in different work modes are considered as a generalized disturbance, and a unified current control plant can be derived for current controller design. Furthermore, the duty cycle limitations in practice are considered, an additional mode for transitional operation is produced, and the corresponding control scheme is also developed. Simulation and experimental test results are provided to validate the correctness and effectiveness of the proposed control scheme.

When an ionic crystal dissolves in solvent, the positive and negative ions associated with solvent molecules release from the crystal. However, the existing form, interaction, and dynamics of ions in real solution are poorly understood because of the substantial experimental challenge. We observed the diffusion and aggregation of polyoxometalate (POM) ions in water by using liquid phase transmission electron microscopy. Real-time observation reveals an unexpected local reciprocating hopping motion of the ions in water, which may be caused by the short-range polymerized bridge of water molecules. We find that ion oligomers, existing as highly active clusters, undergo frequent splitting, aggregation, and rearrangement in dilute solution. The formation and dissociation of ion oligomers indicate a weak counterion-mediated interaction. Furthermore, POM ions with tetrahedral geometry show directional interaction compared with spherical ions, which presents structure-dependent dynamics.

The high-power density and capability of three-port converters (TPCs) in generating demanded power synchronously using flexible control strategy make them potential candidates for renewable energy applications to enhance efficiency and power density. The control performance of isolated TPCs can be degraded due to the coupling and interaction of power transmission among different ports, variations of model parameters caused by the changes of the operation point and resonant peak of LC circuit. To address these issues, a linear active disturbance rejection control (LADRC) system is developed in this paper for controlling the utilized TPC. A virtual damping based method is proposed to increase damping ratio of current control subsystem of TPC which is beneficial in further improving dynamic control performance. The simulation and experimental results show that compared to the traditional frequency control strategy, the control performance of isolated TPC can be improved by using the proposed method.

A heat conduction model in a radial-pattern disc by considering non-uniform heat generation (NUHG) is established in this paper. A series of high conductivity channels (HCCs) are attached on the rim of the disc and extended to its center. Constructal optimizations of the discs with constant and variable cross-sectional HCCs are carried out, respectively, and their maximum temperature differences (MTDs) are minimized based on analytical method and finite element method. Besides, the influences of the NUHG coefficient, HCC number and width coefficient on the optimal results are studied. The results indicate that the deviation of the optimal constructs obtained from the analytical method and finite element method are comparatively slight. When the NUHG coefficient is equal to 10, the minimum MTD of the disc with 25 constant cross-sectional HCCs is specifically reduced by 48.8% compared to that with 10 HCCs. As a result, the heat conduction performance (HCP) of the disc can be efficiently improved by properly increasing the number of HCCs. The minimum MTD of the disc with variable cross-sectional HCC is decreased by 15.0% when the width coefficient is changed from 1 to 4. Therefore, the geometry of variable cross-sectional HCC can be applied in the constructal design of the disc to a better heat transfer performance. The constructal results obtained by investigating the non-uniform heat generating case in this paper can contribute to the design of practical electronic device to a better heat transfer performance.

AIM: To investigate the relationship between pathological myopia and the LAMA1 gene.METHODS: Individuals with pathological myopia and control subjects of Chinese Southern Han were selected. Genomic DNA was collected from 5mL peripheral blood, then the exon27, exon36 in the LAMA1 gene were analyzed by polymerase chain reaction(PCR)and direct sequencing. Allele frequencies were tested for Hardy-Weinberg equilibrium(HWE). The χ 2 Fisher test was conducted to investigate the genotypic and allelic distri-bution between the pathological myopia and control groups.RESULTS: In this study, no gene mutation was identified in the exon27, exon36 in the LAMA1 gene.CONCLUSION: The relationship between pathological myopia and the LAMA1 gene is still waiting for the further proof.

An understanding of solid-liquid interfaces is of great importance for fundamental research as well as industrial applications. However, it has been very challenging to directly image solid-liquid interfaces with high resolution, thus their structure and properties are often unknown. Here, we report a quasi-liquid phase between metal (In, Sn) nanoparticle surfaces and an aqueous solution observed using liquid cell transmission electron microscopy. Our real-time high-resolution imaging reveals a thin layer of liquid-like materials at the interfaces with the frequent appearance of small In nanoclusters. Such a quasi-liquid phase serves as an intermediate for the mass transport from the metal nanoparticle to the liquid. Density functional theory-molecular dynamics simulations demonstrate that the positive charges of In ions greatly contribute to the stabilization of the quasi-liquid phase on the metal surface.