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Chlorella pyrenoidosa peptides (SISISVAGGGR, T1) can effectively alleviate obesity and related metabolic disorders in high-fat mice. However, their lipid-lowering mechanism is still unclear. This research endeavor sought to delve into the potential mediators of T1 anti-obesity in high-fat mice through macrogenomics analyses combined with untargeted metabolomics analyses. The results showed that T1 alleviated HFD-induced increases in body weight, epididymal fat weight, TG, LDL, AST, TNF-α, and IL-1β levels, and increased HDL level. Moreover, T1 reversed the HFD-induced gut microbiota dysbiosis. Specifically, T1 resulted in a massive proliferation of Bacteroides, Parabacteroides, and Alistipes, as well as increased levels of metabolites such as DL-arginine, N-stearoyl GABA, and decreased levels of 7α,24(S)-dihydroxy-4-cholesten-3-one, and hexadecanedioic acid. Correlation analysis showed that T1 alleviated HFD-induced obesity metabolic syndrome and associated inflammation by modulating specific gut microbiota and related metabolites. This provides new ideas for the treatment of diet-induced obesity and related metabolic disorders.

This study examines biomass energy policies in the EU, US, and Japan, noting high implementation rates in Poland (86.5 %) and Finland (90.6 %). Germany's biogas utilization is particularly noteworthy, accounting for 29.6 %. The paper summarizes China's national and provincial waste biomass management and energization policies, encompassing agriculture, biomass energy, and environmental governance aspects. Analyzing China's biomass energy industry reveals challenges requiring a comprehensive development plan based on waste biomass resources and environmental zoning. Proposed solutions include establishing ecological energy agriculture demonstration zones, optimizing policies for environmental benefits, encouraging technological innovation, establishing a trade association, improving standards, setting up a waste biomass fund, introducing green certificates and quotas, and integrating waste biomass into the national carbon trading system.

Low-orbit satellites are widely used in communication, navigation, remote sensing and other fields, which is of great significance to meet the needs of communication and improve the accuracy of navigation and positioning.Integrity technology is an important guarantee for the safe and reliable operation of satellite navigation system.With the mature development of low orbit technology and the gradual application of a large number of low orbit satellites, it is urgent to develop the system integrity monitoring technology under the condition of mixed constellation of high and low orbits.This paper proposed a hybrid constellation integrity monitoring technology for high, middle and low orbit navigation based on genetic algorithm for star selection.On the basis of the traditional optimal geometric accuracy factor selection method, genetic algorithm was introduced to construct a fitness factor based on the linear weighted feature slope of the satellite geometric observation matrix, so as to achieve rapid convergence of user protection level to protection limit.This method further improved the integrity of the receiver by optimizing the way of star selection.Under the accuracy requirement of CAT I, for the ＆quot;BeiDou+StarNet-1＆quot; constellation, the global availability level of the proposed algorithm was 5.60%, and the enhancement effect was the best for the mid-latitude and low-latitude of the Eastern Hemisphere, which were increased by 7.01% and 6.42%, respectively.

Abstract Traditional villages are repositories for preserving human artifacts and cultural heritage. An investigation of the spatial distribution characteristics and factors influencing traditional villages in provincial administrative regions can provide new insights regarding the protection of traditional villages and rural development. This study focused on 275 traditional villages in Henan Province. Using ArcGIS and GeoDa software, we analysed the spatial autocorrelation and heterogeneity of the nearest neighbour index, Gini coefficient, Moran’s I, and kernel density of the villages. Additionally, in conjunction with the Python sklearn library and GeoDetector, 15 indicators were selected to construct a decision tree model, spatial lag regression model, and geographic detector. Then the influence and interaction mechanisms of each indicator were analysed. The results revealed that (1) the spatial distribution of traditional villages in Henan Province was clustered and uneven, with a spatial layout comprising “3 high-density areas + 1 medium-density belt”; (2) overall, the number of traditional villages was negatively correlated with altitude, slope, rainfall, population density, proportion of the minority population, and historical-cultural intensity; and (3) the decision tree model results demonstrated that the selected 15 indicators had good predictive ability and that population density was particularly important. The spatial lag regression model results showed that the spatial distribution of traditional villages was positively correlated with distance from rivers, urbanization rate, and tourism resources, and negatively correlated with population density, per capita GRP, historical-cultural intensity, and NDVI. (4) The GeoDetector results indicated that historical-cultural intensity and population density were the two factors with the most significant explanatory power for the spatial differentiation of traditional villages in Henan Province. In terms of interactive factors, population density $$\cap$$ ∩ population was the strongest interactive driving force, followed by population $$\cap$$ ∩ historical-cultural intensity.

Intensive farming is a primary cause of increased sediment and associated nitrogen (N) and phosphorus (P) loads in surface water systems. Determining their contributing sources, pathways and loads present major challenges in the high-intensity agricultural catchments. Herein, we quantify the sediment sources and magnitude of sediment total N and total P from different sources using a novel application of compound-specific stable isotope (CSSI) and fallout radionuclides (FRNs) of 137Cs and 210Pbex in an intensive agricultural catchment in North China. Sediment sources from surface and sub-surface soils were estimated from FRNs fingerprint and accounted for 62 ± 7% and 38 ± 7% respectively, while surface soil from land uses that originated from hillslope were identified by CSSI fingerprint. Using a novel application of FRNs and CSSI sediment fingerprinting techniques, the dominant sediment source was derived from maize farmland (44 ± 0.1%), followed by channel bank (38 ± 7%). The sedimentation rate (13.55 ± 0.30 t ha−1 yr−1) was quantified by the 137Cs cores (0–60 cm) at the outlet of this catchment. The total N and total P in sediment were both mostly derived from maize farmland and least from channel banks. The channel banks are significant sediment sources but contribute little to the input of sediment N and P for eutrophication. It implies that chemically-applied farmlands are the main hotspots for catchment erosion control and pollution prevention. The novel application of FRNs and CSSI techniques cost-effectively quantified sediment N and P loads from different sources with a single visit to the catchment, enabling rapid assessment for optimizing soil conservation strategies and land management practices. Keywords: Sediment sources, Land use, N and P loads, Compound-specific stable isotope, Fallout radionuclides.

The precise evaluation of micro-crack sizes and locations is crucial for the safe operation of structures. Traditional detection techniques, however, suffer from low spatial resolution, making it difficult to accurately locate micrometer-scale cracks. A method and experimental study were proposed in this paper for identifying and locating micro-cracks using optical fiber strain sensing based on OFDR to address this issue. The feasibility of this method for micro-crack detection was verified by the combination of a polyimide-coated sensing optical fiber (PISOF) and tight sheath sensing optical fiber (TSSOF). A calculation method for micro-crack widths based on distributed optical fiber strain curves was established, and the test results of different optical fibers were compared. Through multiple verification experiments, it was found that the strain peak curves of both fiber types could accurately locate micro-cracks with a precision of 1 mm. Additionally, the crack widths could be obtained by processing the distributed strain curves using a computational model, enabling the accurate capture of micro-crack characteristics at the 10 μm level. A strong linear relationship was observed between the optical fiber stretching length and the crack width. Notably, the relative error in calculating the crack width from the strain curve of PI fiber was very small, while a linear relationship existed between the maximum strain value of the TSSOF and the crack width, allowing for the calculation of the crack width based on the maximum strain value. This further validated the feasibility of the method designed in this paper for the analysis of micro-crack characteristic parameters.

Defects occurring during the welding process of metal structural components directly affect their overall strength, which is crucial to the load-bearing capacity and durability of the components. This signifies the importance of accurate measurement and assessment of weld strength. However, traditional non-destructive testing methods such as ultrasonic and non-contact camera inspection have certain technical limitations. In response to these issues, this paper analyzes the detection principle of weld strength, revealing that weld defects reduce the effective area of the structural bearing section and cause stress concentration around them. Through repeated experimental data analysis of samples, strain distribution data along the one-dimensional direction caused by defects such as slag inclusion and porosity were obtained. Experimental results show that this method can identify defect types in welds, including slag inclusion, porosity, and unevenness, and accurately measure the location and size of defects with a precision of 0.64 mm, achieving qualitative analysis of weld defects. Additionally, by deploying distributed optical fiber sensors (DOFS) at different vertical distances along the weld direction, the propagation law of stress induced by different types of weld defects on samples was thoroughly analyzed. This further validates the advantages of this method in weld strength detection, including high spatial resolution, high sensitivity, and non-destructive measurement.

Obesity can cause a wide range of metabolic diseases, but safe and effective treatments are still lacking. Chlorella pyrenoidosa (C. pyrenoidosa) peptides have a variety of biological activities, but their lipid-lowering effects in vivo are rarely reported. In this study, one (SISISVAGGGR, T1) of the six C. pyrenoidosa peptides with the best lipid-lowering and gut microbial stability maintenance was screened. Then, the anti-obesity effects of different doses of T1 (300 mg/Kg/d, 100 mg/Kg/d) were evaluated in mice fed a high-fat diet (HFD). The results showed that T1 supplementation alleviated HFD-induced weight gain and lipid accumulation, reduced fasting blood glucose and low-density lipoprotein (LDL) and elevated high-density lipoprotein (HDL) levels. T1 improved insulin resistance and attenuated hepatic lipid accumulation and meta-inflammation in both liver and adipose tissues in obese mice. This study demonstrated a novel C. pyrenoidosa peptide as a potential prebiotic with beneficial effects on obesity and related metabolic disorders.

Abstract Non‐stationary interferences are parts of the global navigation satellite system (GNSS) threats; this paper focusses on the impact of intermittent interferences on the baseband processing of the array GNSS receiver. We call the jitters of channel response caused by distributed intermittent interferences as channel scintillations. The inevitability of the channel scintillations under intermittent interferences was illustrated first. Then, the characteristics of channel scintillations were analysed through theory analysis and simulations. Finally, the impact of channel scintillations on the receiver baseband processing was assessed. The results show that though the intermittent interferences power can be suppressed completely by the anti‐jamming filter, the phase lock loop may lose lock due to channel scintillations.

Power inversion algorithms (PI) are widely used by ant-jamming receivers in harsh environment, but it also induces pseudo-range measurement error which is fatal to high precision receivers. In this paper, it proposes a more accurate method based on the S Curve Bias (SCB) to evaluate the pseudo-range bias which can actually affect the positioning results, as it excludes a fixed time delay contained in the directly differing method. When using this method to assess the bias, it is found that pseudo-range errors can be influenced by many factors including the type of interference. Simulation as well as experiment based on a 4-element array antenna are designed and carried out. The simulation has shown that both SOP-PI and STAP-PI will bring bias to pseudo-range measurement. Specifically, the maximum bias caused by SOP-PI is 1m while the bias caused by STAP-PI is up to 10m. Moreover, comparing to the method which directly differs the pseudo-range of output signal and the reference signal, the method proposed in this paper has better performance. Furthermore, the experimental results verify the effectiveness of the proposed evaluating method.

This paper analyzes the performance of sample matrix inversion (SMI) filter used by antenna array receivers in pulse interference environment. Firstly, from the perspective of comparison, it is proved that the theoretical optimal signal to interference noise ratio (SINR) of SMI filter under pulse interference is the same with that under continuous interferences. Then the convergence characteristics of SMI filter under pulse interference are deduced, and the relationship between the convergence speed and length of training samples and duty of interferences is given. Finally, the results of signal simulation are consistent with those of numerical analysis, which verifies the correctness of theoretical analysis. The results show that the convergence speed of SMI filter decreases under pulse interference, and the SMI filter needs more training samples to suppress the pulse interference effectively.

Introduction: Distributed wideband jamming (interference) is commonly used in navigation countermeasure. Due to the limited volume of GNSS (Global Navigation Satellite System) array antenna receiver, the number of interferences usually exceeds the number of array elements. At present, the anti-jamming capability and mechanism of Global Navigation Satellite System array antenna against distributed sup-DOF (Degree of Freedom) interference have not been fully studied.Methods and innovation: To solve this problem, this paper analyzes the characteristics of GNSS System array antenna against sup-Degree of Freedom interference by formula derivation and simulation. Firstly, the definition of sup-Degree of Freedom interference of Global Navigation Satellite System array antenna is proposed from the perspective of spatial anti-jamming; Secondly, the directional characteristics of Global Navigation Satellite System array antenna for sup-Degree of Freedom interference suppression are analyzed.Results: The results show that the performance of sup-Degree of Freedom interference suppression is sensitive to the direction and distribution of interference. On the one hand, the residual interference power varies from interference direction and distribution, while the minimum value of which is zero and the maximum value is the sum of interference power. On the other hand, the suppression performance of UCA (Uniform Circular Array) and central Uniform Circular Array is periodic along azimuth. If the number of elements on the circumference is M (M ≥ 3), the period of the suppression performance is 4π/M/3+(−1M+1.Discussion: The conclusion of this paper show the upper and lower bounds of sup-Degree of Freedom interference suppression performance and the variation rule in azimuth, which can be used in the fields such as interference deployment, anti-jamming performance evaluation and anti-jamming algorithm development.

Summary: The interaction of water molecules with graphene oxide (GO) at the interface or surface will lead to the reversible deformation response of GO-based materials. However, the fabrication of structurally stable and highly sensitive GO-based humidity-responsive films remains a challenge. Since the stability and sensitivity of GO-based humidity-responsive devices are significantly limited by the deformation differences between different components. Herein, we demonstrate that polyamidoamine (PAMAM) bridge-enhanced carboxylated holey GO (hGC/PAMAM) films are sensitive to moisture and exhibit excellent stability in water. Experiments and molecular dynamics (MD) simulation show that the formation of N-C=O between PAMAM and GO sheets significantly increased the interlayer bonding force. Dynamic monitoring of the surface strain of the hGC/PAMAM films showed that the strains spread a gradient from the high-humidity to the low-humidity side, causing asymmetric expansion along the horizontal and vertical directions. This work will provide a better understanding of the mechanism of water molecule transport between layers.

The Global Navigation Satellite System (GNSS) has been applied to all aspects of social livelihood and military applications and has become an important part of national infrastructure construction. However, due to the vulnerability of GNSS, satellite navigation jamming technology can pose a serious threat to GNSS security applications, and this has become a research hotspot in the field of navigation countermeasures. In this paper, satellite navigation jamming technologies are divided into suppression jamming and deception jamming, and the research status of satellite navigation suppression jamming and deception jamming technologies are sorted by three aspects: jamming technology classification, jamming efficiency evaluation, and jamming source deployment. Finally, the future development trend of satellite navigation jamming technology is summarized.

The process and mechanism of gold mineralization are frontier issues. The Dunbasitao deposit is the most important gold deposit discovered along the Armantai suture zone, East Junggar, NW China, which indicates the potential for future ore exploration in this area. Orebodies are mainly hosted in Lower Carboniferous Jiangbasitao Formation volcano-sedimentary rocks, and the ores are characterized by multistage pyrites. Based on microscopy and backscattered electron imaging studies, pyrites are classified into five types: the pre-ore framboidal/colloidal Py0; the early-stage coarse-grained, cubic, and homogeneous Py1; and the middle-stage fine-grained, cubic/pyritohedron Py2 that includes Py2a (core), Py2b (mantle), and Py2c (rim). The results of the EPMA and in situ LA-ICP-MS analyses show that trace elements of pyrite mainly occur in two forms: solid solutions and invisible or visible inclusions. Mn, Co, Ni, and As enter the pyrite lattice, whereas Ti occurs as mineral inclusions, and Au, Cu, Zn, Sb, and Pb can occur in both forms. Au and As show a positive linear relationship with r = 0.850. Py2b has much higher Au contents (20.1 to 201 ppm) than other pyrite types (Py0: 0.01 to 0.36 ppm; Py1: 0.01 to 0.02 ppm; Py2a: 0.31 to 2.48 ppm; and Py2c: 0.18 to 18.0 ppm). The Dunbasitao deposit is classified as an orogenic gold deposit using the two latest machine learning classifiers based on pyrite trace element data. Fluid immiscibility, sudden cooling, and the substitution of S1− with As1− might be crucial mechanisms leading to Au precipitation. Initial ore-forming fluids brought major amounts of As, Au, Co, Ni, Se, Zn, Ag, Cd, Sn, and other elements, and the Jiangbasitao Formation host rocks contributed a certain amount of As, Ni, Cu, Sb, Pb, and Bi, at least.

Model strength and biases are two main factors for GNSS integer ambiguity resolution. Due to the nonideal GNSS signal, the receiver's observations will be biased. In GNSS relative positioning, the double difference pseudorange bias cannot be eliminated due to the different receiver's technical parameters between base and rover stations, which are generally ignored. This paper investigates single epoch ambiguity resolution performance in the presence of pseudorange biases. Specifically, two commonly ambiguity resolution methods are used, including the bootstrapped and the Least-Squares Ambiguity Decorrelation Adjustment (LAMBDA) methods. A transfer model of pseudorange biases affecting integer ambiguity resolution is proposed to analyze the influence of pseudorange biases theoretically. The theoretical analysis and simulation results show that the pseudorange biases can affect the float ambiguities and decrease the success rate of integer ambiguity resolution. The simulation result shows that the performance of bootstrapped method may exceed the LAMBDA method in the presence of pseudorange biases. Further, a real data experiment is conducted to confirm the influence of pseudorange biases on ambiguity resolution. Both the simulations and the experimental results show that decimeter-level pseudorange biases can also decrease the success rate of ambiguity. The real data experiment indicates that with the pseudorange biases modified, the success rate of ambiguity fixing may increase up by 5% in zero baseline. The better the geometry of the observations, the robuster the ambiguity resolution against pseudorange biases.

The global satellite navigation system represented by global position systems (GPS) has been widely used in civil and military fields, and has become an important cornerstone of space-time information services. However, the frequency band of satellite navigation signals is open, and the frequency points overlap with some radars and communication systems, which brings challenges to the application of satellite navigation. Time-domain adaptive filtering technology is a typical anti-jamming method which can suppress the narrow-band interference faced by satellite navigation. However, in the process of suppressing narrow-band interference, the navigation signal will be distorted, which is mainly reflected in the distortion of the spectrum of the navigation signal, which will lead to the enhancement of the side lobes in the correlation function. In this paper, we focus on time-domain adaptive anti-jamming, study the mechanism of correlation function sidelobes lift caused by narrow-band interference suppression, and propose a correlation function sidelobes suppression method based on time-domain adaptive anti-jamming, which can be realized without losing anti-jamming performance. The simulation experiment verifies the validity of the mechanism analysis of the sidelobes lift of the correlation function and the effectiveness of the proposed method. The analysis results and the proposed method are of great significance, which is reflected in the improvement of the anti-jamming performance and acquisition performance of satellite navigation receivers.

Bridges are special infrastructures that emit large amounts of carbon dioxide from construction. Attention should be given to the carbon cost generated by the bridge, which includes its direct economic cost; the carbon cost is the largest driving force encouraging the enterprise to implement carbon emission reduction measures. In this study, the life cycle assessment (LCA) method is applied to carbon emissions in the bridge construction stage, which include emissions from material production, transportation and on-site construction; then, a carbon emission calculation model for the construction stage is established. Next, the carbon cost calculation model for the bridge in the construction stage is determined by combining the carbon pricing mechanisms of carbon emission taxing and trading to monetize carbon emissions. Finally, by taking a bridge in Beijing as an example, the carbon emissions in the bridge construction stage are calculated, and the carbon cost is calculated. The results show that carbon emission monetization is beneficial for clarifying the environmental impact of bridge construction; these calculations should be included in cost accounting.

The first complete chloroplast genome of Campylotropis grandifolia Schindl. is reported and characterized in this study. The whole chloroplast genome was 153,213 bp in length with 128 genes, including 81 protein-coding genes, 39 tRNAs, and eight rRNAs. Maximum-likelihood (ML) phylogenetic analysis of 25 legume species strongly supported that Campylotropis is most closely related with Kummerowia and Lespedeza, which is consistent with previous studies.

GNSS is now being speedily expanded to our daily life, but the positioning precision still can hardly meet the demands of many high-precision applications, such as approaching landing system on airports. Due to the development of GNSS, quadruple-frequency signals are now available in China's BeiDou Navigation Satellite System (BDS) and the European Galileo system, which can contribute to positioning precision. Positioning precision can not be improved obviously by quadruple-frequency carrier phases until cycle slips are detected and repaired. A method using four linear combinations to detect and repair quadruple-frequency cycle slips is proposed in the paper. The choices of the four linear combinations are conducted in cascaded steps in accordance to the cycle slip fixing probability. When the four detection combinations are determined, cycle slips on original carrier phase observations can be uniquely determined. The proposed algorithm has been tested on real 30-second quadruple-frequency static observations of BDS and Galileo and on real 0.05-second quadruple-frequency kinematic observations of BDS and Galileo. Simulated and real cycle slips are tested. The results show that the proposed algorithm can detect and repair cycle slips even for one cycle effectively.

A code recovery method of a global navigation satellite system (GNSS) authorized service (AS) signal component is described under the condition of a high signal-to-noise ratio. The correctness of the spreading code verification can be used to monitor the health status of satellite payloads. Pseudo code recovery is a precondition to verify the validity of pseudo code. For a specified GNSS signal multiplexing approach, the distribution of baseband signal phase points on a constellation diagram is established. The open service signal component and the AS signal component correlate with each other on the unit circle. By wiping off the signal carrier, each signal component can be recovered according to the phase table of the transmitted signal. Different states of the global positioning system L1 signal is introduced, and the AS signal component recovery performance under different constant enveloping modulations is analyzed. This paper provides a reference for the analysis, evaluation, and system optimization design of a GNSS signal. Relevant research results can be applied to satellite signal quality monitoring and electronic reconnaissance.

Given the importance of catalysts in the chemical industry, they have been extensively investigated by experimental and numerical methods. With the development of computational algorithms and computer hardware, large-scale simulations have enabled influential studies with more atomic details reflecting microscopic mechanisms. This review provides a comprehensive summary of recent developments in molecular dynamics, including ab initio molecular dynamics and reaction force-field molecular dynamics. Recent research on both approaches to catalyst calculations is reviewed, including growth, dehydrogenation, hydrogenation, oxidation reactions, bias, and recombination of carbon materials that can guide catalyst calculations. Machine learning has attracted increasing interest in recent years, and its combination with the field of catalysts has inspired promising development approaches. Its applications in machine learning potential, catalyst design, performance prediction, structure optimization, and classification have been summarized in detail. This review hopes to shed light and perspective on ML approaches in catalysts.

The Hopkinson pressure bar is widely used to measure the reflected pressure of blast waves over a short distance. However, dispersion effects will occur when the elastic stress waves propagate in the pressure bar due to lateral inertia, and there will be errors between the signals obtained from the sensors and the actual loading. For the free surface velocity measured in our system, we developed a local phase-amplitude joint correction method to convert the measured velocity into the average reflected pressure of a shock wave at the impact end of the bar, considering factors such as propagation modes of the elastic wave, the frequency components’ time of arrival, velocity variation over the bar axis, and the stress–velocity relationship. Firstly, the Pochhammer–Chree frequency equation is calculated numerically, and the first to fourth orders of phase velocity, group velocity, normalized frequency, and propagation time curves of elastic wave propagation in 35CrMnSiA steel are obtained. Secondly, the phase and amplitude correction formulas for calculating average reflected pressure from center velocity are derived based on the propagation mode of the axial elastic wave in the pressure bar by analyzing the time-frequency combined spectrum obtained by short-time Fourier transform. Thirdly, a local phase-amplitude joint correction algorithm based on propagation mode is proposed in detail. The experimental tests and data analyses are carried out for eight sets of pressure bar. The results show that this method can identify the propagation mode of elastic waves in the bar intuitively and clearly. The first three orders of propagation modes are stimulated in the bar 04, while only the first order of propagation is stimulated in the other eight bars. The local phase-amplitude joint correction algorithm can avoid correcting the component of the non-axial elastic wave. The rising edge of the average stress curve on the impact surface of bar 01 and bar 04 is corrected from 4.13 μs and 4.09 μs to 2.70 μs, respectively.