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High Mach flight has put forward more stringent requirements for the material and structure design of new generation of high-speed vehicles. This paper reviews the application of ceramic matrix composites（CMCs） in the structural design of aircraft from the aspects of selection，application，and evaluation，and then the future development direction is put forward to provide reference for aircraft ceramic matrix composite structure design. The selection criteria and corresponding preparation methods of CMCs in different application scenarios are comprehensively reviewed，the typical applications of CMCs in aircraft structures are systematically introduced，and the evaluation criteria and ground test methods of the materials under near-service conditions are analyzed. To order to meet the future demands of aircraft，it is necessary to integrate computer-aided optimization technology and innovative preparation methods to enhance the temperature resistance and fatigue performance of CMCs. Developing highly reliable，long-life joining techniques and integrated design solutions will fully leverage the advantages of these materials. Additionally，in-situ characterization techniques under multi-physical field coupling need to be developed to obtain the performance evolution behaviour of CMCs in actual use，providing a reliable basis for the lightweight structural design of aircraft.

The variation rule of deformation structure and magnetic properties of high strength non-oriented electrical steel with cold rolling were studied by field emission scanning electron microscopy(SEM+EBSD), rapid temperature tube furnace and AC magnetic properties measuring instrument. The results show that the rough strips with a large number of substructures and smooth strips with a small amount of deformation are formed in cold-rolled high strength non-oriented electrical steel. The rough strip has a γ orientation, mainly {111}〈110〉, and the smooth strip has a {112}〈110〉 and {001}〈110〉 orientation. In the rough strips, there are a lot of shear bands with width of about 2-3 μm, which show an angle of 20°-35°to the rolling direction. And the quantity increases gradually with the increase of the reduction rate. There is a certain misorientation between the shear band and the matrix. With the increase of the reduction rate, the shear band gradually changes from {111}〈110〉 to {223}〈110〉, and the misorientation between the shear band and the matrix gradually increases. After annealing, the texture of Goss and {111} increases, while the texture of {001} decreases. The rolling direction magnetic induction intensity increases, the transverse magnetic induction intensity decreases, the magnetic anisotropy is significant, and the iron loss decreases.

Seven samples of Wuyi rock tea (cv. Shuixian) stored for different times (0, 5, 10, 15, 20, 25, and 30 years) were collected to investigate the effect of storage time on the flavor quality of Wuyi rock tea by the combined use of sensory evaluation, non-volatile and volatile composition analysis and chemometrics methods. The results showed that the transformation of the flavor quality of Wuyi rock tea during storage was divided into three stages: 0–5, 10–15, and 20–30 years. As the storage time increased, the taste gradually transformed from mellow to stale, and a sour taste appeared at the middle stage of storage and then faded away at the late stage. The aroma gradually changed from flowery and fruity to aged, woody and herbal. A significant decrease in the content of tea polyphenols, catechins-like and theaflavins and an increase in the content of soluble sugars were the major reasons for the taste changes. Changes in the contents of 15 characteristic volatiles, including indole, trans-nerolidol, dihydroactinidiolide, hotrienol, α-terpineol, methyl salicylate, β-ionone, and (Z)-hexanoic acid-3-hexenyl ester, were the key factors affecting the aroma changes. This study provides a scientific reference for the storage and consumption of Wuyi rock tea.

Due to the large-scale development of rooftop photovoltaics and the continuous improvement of the national carbon trading market, the carbon credits generated by rooftop photovoltaics power generation can obtain additional income through carbon allocation offset or participation in carbon trading market. Firstly, the path and methods of participating in the carbon trading market for rooftop photovoltaic projects are studied, focusing on how large-scale rooftop photovoltaic projects participate in the carbon trading market and the degree of impact on the project's economy. Secondly, the life-cycle economic model of rooftop photovoltaic with carbon trading income is established based on the power generation model. Thirdly, in order to quantitatively analyze the income of carbon trading, an improved grey prediction GM(1, 1) model based on the differential threshold filtering method is proposed to predict the future carbon price. Finally, an example of large-scale rooftop photovoltaic is analyzed. The results show that large-scale rooftop photovoltaic considering participation in the carbon trading market has a relatively significant economic improvement.

Correct network topology is the basis of power grid analysis and control. Because of the lack of measurement on breakers， the identification of breaker states is particularly important in the distribution network. According to the characteristics of closed-loop construction and open-loop operation of the distribution network， section breaker graph is developed to describe the connectivity of the distribution network. The property of tree is used to describe the radial structure constraints of the operation of the distribution network. Based on the principle of weighted minimum absolute value， a identification model is developed， which aims to minimize the adjustments of breaker states and the sum of weighted absolute value of measurement errors. The proposed identification model is a mixed integer linear programming （MILP） problem in mathematic， which can be solved by the simplex method combined with the branch and cut frame. The correctness of proposed model and effectiveness of the proposed method are verified by simulation case.

Objective: This study aimed to investigate the quality changes during the fermentation of sauerkraut without salt and inoculated with lactic acid bacteria and during low-temperature storage. Methods: The basic physicochemical indexes and quality changes of sauerkraut during fermentation were analyzed. Results: The unsalted sauerkraut reached maturity at 5 d of fermentation and the pH, nitrite content, reducing sugar content and vitamin C content decreased significantly (P

BACKGROUND The fast detection of Cu, Pb, Zn and Ni in geochemical samples helps to determine the level of heavy metal pollution, thus assisting in the employment of efficient treatments. OBJECTIVES To establish a method for the simultaneous determination of Cu, Pb, Zn and Ni in geochemical samples by AC Arc direct reading atomic emission spectrometry with solid sampling technique. METHODS With sodium fluoride, alumina, silicon dioxide and carbon powder as buffer agents and germanium as the internal standard element, the element analysis line pairs were optimized, and the exposure time was also optimized at 25s. The standard curve of synthetic silicate was corrected using national first-class reference materials (soil, rock and sediment), so as to reduce the interference of the matrix. Sensitive line and hyposensitive line were selected to enhance the accuracy as well as expand the measurable linear range of elements. Average value of two parallel analyses was adopted for further improved analytical precision. RESULTS The detection limits of Cu, Pb, Zn and Ni were 0.45μg/g, 1.46μg/g, 2.40μg/g and 1.58μg/g, respectively. The precision ranges of the method were 1.36%-6.25% for Cu, 1.17%-8.06% for Pb, 1.64%-9.68% for Zn and 0.91%-5.31% for Ni. Measured values with this method for the national first-class reference materials of soil, sediment and rock were consistent with the certified values (|△logC| ≤ 0.05), qualification rates of the actual samples and external quality control samples were all above 90%. CONCLUSIONS With simple operation, direct solid sampling technique is applied. The method reported here is more environmentally friendly compared to the acid dissolving method, sample contamination caused by reagent blank and vessels used is avoided at the same time. The average results of twice spectral acquisitions are calculated, which is more accurate and precise than the single analysis reported in the literature. All indicators of this method are better than the requirements of regulation (1:250000) DZ/T 0130.5-2006.

Due to the limitations of configuration scenarios， energy storage capacity configuration takes long time and the net profit value of energy storage capacity is small. Research on energy storage capacity configuration method for power system based on an improved particle swarm optimization （PSO） is proposed. First， the power system energy storage capacity is determined， and the storage capacity configuration constraints are analyzed in respect of the remaining power， charging and discharging efficiency， and reliability of the energy storage system； then， with the objective of maximum net revenue of storage capacity configuration， an economy model of the power system is constructed， and the improved particle swarm algorithm is introduced to solve the model and complete the configuration of the power system energy storage capacity. The experimental results show that the proposed method takes shorter configuration time while owning higher net energy storage capacity revenue， which verifies the application performance of the method.

Objective To explore the intertemporal decision⁃making disorder in patients with Parkinson's disease (PD). Methods From January 2020 to August 2021, a total of 36 patients with PD (PD group) who diagnosed and treated in The Second People's Hospital of Hefei and The Second Affiliated Hospital of Soochow University were selected, and 39 healthy controls (control group) with matched gender age and eudcation were recruited. Hamilton Anxiety Rating Scale (HAMA), Hamilton Depression Rating Scale (HAMD), Mini⁃Mental State Examination (MMSE), Verbal Fluency Test (VFT), Digit Span Test (DST), and Stroop Color⁃Word Test (SCWT) were used to evaluate the neuropsychological characteristics, the delay⁃discount rate K value in the intertemporal decision⁃making paradigm were used to evaluate the intertemporal decision⁃making ability. Results Compared with control group, the PD group had a decrease in MMSE score (Z=⁃4.536, P=0.000), correct number of VFT (Z=⁃4.555, P=0.000), correct repetition of DST⁃forwards (Z=⁃4.696, P=0.000) and DST⁃backwards (Z=⁃3.261, P=0.001), while had an increase in HAMA score (Z=⁃5.153, P=0.000), HAMD score (Z=⁃5.637, P=0.000), Stroop C-A (Z=⁃7.105, P=0.000) and K value (Z=⁃3.209, P=0.004). Correlation analysis showed that there was no correlation between K value and MMSE score, correct number of VFT, Stroop C-A, and correct repetition of DST⁃forwards and DST⁃backwards in PD patients (P＞0.05, for all). Conclusions Patients with PD have symptoms of intertemporal decision⁃making disorder. They can't reasonably balance the value of delayed reward, prefer immediate reward, and have more impulsive decision⁃making behavior.

Objective: Combined with the determination of macromolecular protein, amino acid and total protein, a quantitative analysis method for the content of small molecular peptides in infant formula milk powder was established. Methods: The contents of total protein, polymer protein and free amino acid in infant formula milk powder were determined by Kjeldahl nitrogen determination method, gravimetric method and ion exchange chromatography, and then the contents of small molecular protein peptide were calculated. Results: The precision RSD of the macromolecular protein detection (n=6) was 0.74%; The recovery rates of the 17 kinds of amino acids were 91.0%~103.2%, and the relative deviations of the detection results were 0.6%~ 2.5%. The recovery rates of small molecular weight peptides were 95.2%~98.2%. Conclusion: The established method has been validated by methodology, with good precision and recovery rate, and can be used for the determination of small molecular peptides in infant formula milk powder.

F-doped ZnO (FZO) films were prepared by reactive sputtering using Zn/ZnO/ZnF2 mixture as the target at substrate temperature (Ts) of 150℃ and 300℃ and sputtering atmosphere of Ar+O2 and Ar+H2. The effect of gas flux, Ts, and sputtering atmosphere on the structure and transparent conductive properties of the thin film was investigated. The results show that for FZO films prepared under Ar+O2, Ts=300℃ is conductive to the preparation of films with (002) preferred orientation, high crystallinity, low compressive stress and good transparent conductive properties. For the films prepared under Ar+H2, with the increase of Ts to 300℃, the crystallinity and transmittance of the films improve and the compressive stress reduces, but the film thickness significantly reduces and leads to the deterioration of the conductive properties of the films. The FZO films prepared in the two atmospheres are compared, and it is found that the films prepared in Ar+H2 can obtain better transparent conductive properties (the resistivity of 3.5×10-3 Ω·cm and the average transmittance in visible range of 87%) at 150℃ and in H2 flux range of 0.8-3.2 mL·min-1. The etching effect of H plasma and H doping in the Ar+H2 atmosphere, the bombardment of O ions and the change of oxygen defects of the films in the Ar+O2 atmosphere, the enhancement in reaction activity and mobility of deposited atoms with increasing Ts, and the relationship between Eg and carrier concentration are discussed in detail.

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. Traditional DPN diagnostic methods are based on clinical symptoms and signs as well as electrophysiological examination, which are mainly used to detect the lesions of large nerve fibers. However, the small nerve fibers are the earliest ones damaged in DPN. Corneal confocal microscopy (CCM) can analyze the changes of corneal nerve fibers under a high power microscope. It is a rapid, repeatable and quantitative noninvasive technique to measure small nerve fibers. It can diagnose DPN early and evaluate neuromorphological changes prospectively. It has a good application expectation. During this article, we summarized the role and limitations of DPN's most reliable parameters of corneal nerve in evaluating diabetic autonomic neuropathy and diabetic micro-vascular complications. Further, we reviewed the clinical application of CCM in evaluating diabetic neuropathy and analysis methods of CCM related artificial intelligence, in order to provide references for clinical diagnosis and treatment.

The construction industry is a pillar of the national economy. The complex international competition and the pressure from domestic reforms necessitate improvement on the core competitiveness of Chinese construction enterprises. In this article, we first analyze the development status and challenges of the core competitiveness of Chinese construction enterprises. Subsequently, we summarize the factors that influence the core competitiveness of Chinese construction enterprises using a fishbone diagram and through literature review and expert consultation, including human resource management, scientific and technological innovation, culture and brand building, project management, professional construction, and industrial chain integration. Furthermore, we propose corresponding suggestions and countermeasures from the perspectives of government and enterprise. Specifically, the government should improve the mechanism of scientific and technological innovation, improve relevant standards and policies of green construction, and enhance industry governance. Moreover, construction enterprises should improve the quality of human resource management, promote scientific and technological innovation, create brand soft power, integrate high-quality resources of the industrial chain, and promote core business advantages.

Under global economic competition, rescaling has become an important cross-border governance means to control the development of domestic space to attract capital flows and foster regional economic development momentum. City integration is a kind of urban regional scale, and its mechanism of cross-border governance has gradually become an important regional integration issue. At present, research on cross-border governance from the perspective of rescaling focuses on urban areas represented by urban agglomerations and metropolitan areas and new functional areas represented by state-level new areas, with limited research on the scale of city integration at the meso level. The discussion on the role and status of corresponding governance subjects, construction mechanisms, and incentive mechanisms needs to be enriched. In this paper, the evolution of cross-border governance is discussed from the perspective of rescaling, taking Guangfo city integration, which is relatively mature in the process of domestic city integration, as an example. The study finds that, taking the introduction of the outline of the reform and development plan for the Pearl River Delta region in 2008 and the outline of the development plan for the Guangdong-Hong Kong-Macao Greater Bay Area in 2019 as the target, the city integration process of Guangfo has experienced two stages of rescaling: from the governance scale of an "administrative area" to that of a "functional area" represented by the pilot zone for the high-quality development integration of Guangfo. By comparing and analyzing the cross-border governance mechanisms of city integration across different scales, this study finds that the city integration governance stage of the "functional area" scale, first, enriches the participation of multiple governance subjects, extending from "city-district-town" multi-level government to the functional platform management committee and platform joint venture company. Second, on the basis of the project implementation mechanism led by municipal departments, the construction mechanism strengthens the planning, construction, and operation mechanisms guided by functional areas and, taking the whole cycle as the concept, increases emphasis on integrated planning, construction, and operation. Third, the incentive mechanism has shifted from the driving of political instructions and economic benefits to the striving for policy and the sharing of institutional dividend. Both "administrative area" and "functional area" are the positive scales restructuring strategy of Guangfo to deal with the global competitive environment and respond to the requirements of national strategy. The two-stage cross-border governance mechanism is neither beneficial nor harmful, but is a choice to adapt to the different development stages of city integration. The governance mechanism of the "functional area" scale can be regarded as the experience retention and gradual reform of Guangfo's original governance mechanism, to improve the governance efficiency of the city integration and competitiveness. Guangfo's practice of using rescaling to promote cross-border governance reform and deepening in the last ten years can provide a certain reference for cross-border governance in the Guangdong-Hong Kong-Macao Greater Bay Area and other metropolitan areas in China. However, it should be pointed out that at present, the rescaling of the pilot area is more reflected in spatial planning and cooperation agreements, and has failed to produce a spatial governance subject that is fully integrated with the new scale. In addition, the deeper benefit sharing and risk responsibility sharing mechanism still needs to be strengthened.

The hot corrosion behavior of the second generation nickel base single crystal superalloy DD421 coated with 90%(mass fraction) Na2SO4+10%NaCl (molten at 750 ℃) and pure Na2SO4 (solid state at 750 ℃) was investigated by salt coating method in 750 ℃ atmosphere (without SOx atmosphere). The results show that in the corrosion medium of molten mixed salt, the sulfidation reaction is mainly caused by the corrosion of liquid molten salt. After 100 h of hot corrosion, the main corrosion products are typical simple oxides (Al2O3, Cr2O3, TiO2) and Ni/Cr/Ti sulfides. However, in the pure Na2SO4 solid salt hot corrosion experiment, the corrosion products of the alloy after 100 h of hot corrosion are basically the same as those in the mixed salt test, but the thickness of the corrosion layer is relatively thinner and the size of sulfide is relatively larger. Combined with thermodynamics and microstructure analysis, it is clear that the alloy elements can react with solid Na2SO4 salt in the corrosion environment without SOx atmosphere.

Choriocarcinoma (CC) is a malignant trophoblastic tumor that occurs in women of childbearing age. Its cure rate could be over 90% following single drug or multidrug chemotherapy with methotrexate, 5-fluorouracil and etc. Chemoresistance is the main cause of treatment failure in CC, and the mechanisms have yet to be elucidated. Most of the previous works on the chemoresistance of CC focused on the transcript and protein levels, and much less attention was put on the metabolic level. In this study, the metabolomic phenotypes of two lines of CC cell, methotrexate-resistant cell (JEG3R) and methotrexate-sensitive cell (JEG3), as well as the medium extracts, were investigated using an NMR-based metabonomics method. The results showed that the chemoresistance of CC was likely related to disturbed glucose metabolism. Glucitol accumulation was observed only in the JEG3R cell line, suggesting the involvement of aldose reductase in the development of chemoresistance. In addition, methotrexate chemoresistance was also associated with lactate accumulation and stimulated alanine synthesis to fuel the Krebs cycle. The levels of amino acids, nucleotides and phosphocholine in the resistant line showed significant differences from the non-resistant line, and positive correlations with the proliferation rate of CC. This study provided insights into the chemoresistance of CC from the metabolism aspect.

Objective To observe and analyze the relationship between serum Hcy concentration and coronary artery disease (CAD) in patients with normal high-sensitivity C-reactive protein (hsCRP) level. Methods A total of 4 097 patients (2 787 males and 1 310 females) who underwent coronary angiography and had hsCRP ≤2.0 mg/L in the Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University from April 2017 to April 2019 were enrolled in this study. According to serum Hcy level in the tertile, they were divided into high, middle and low level groups (>19.40, >13.90~19.40, ≤13.90 μmol/L). The differences in baseline data and clinical biochemical parameters were compared among the groups. Logistic regression analysis was used to evaluate the relationship between Hcy concentration with CAD prevalence and severity. Results The severity of CAD was more serious in the high Hcy group than the low Hcy group (Gensini score: 35.39±33.95 vs 26.25±27.04, P < 0.001), and the serum Hcy level was significantly positively correlated with the Gensini score (r=0.122, P < 0.001). The incidence rates of acute myocardial infarction (15.2% vs 9.2%, P < 0.001) and three-vessel disease (34.8% vs 29.0%, P=0.004) were significantly higher in the high Hcy group than low Hcy group. Logistic regression analysis showed that after adjustment for all baseline differences, serum Hcy level was still positively correlated with the prevalence (P=0.006) and severity (P=0.002) of CAD and the incidence of acute myocardial infarction (P=0.001). Conclusion Serum Hcy may be an independent predictor of CAD prevalence and severity in patients with normal hsCRP level.

Objective To investigate the application of superb micro-vascular imaging(SMI) technology in accurately targeted biopsy of prostate cancer. Methods One month after 87 patients with clinically suspected prostate cancer received the first systematic 12-points puncture, 48 patients received system 12-points puncture, 39 patients received SMI technology to accurately target abnormal areas replacing local system puncture. According to histo pathological confirmation of the first puncture, the results of two methods in prostate cancer biopsy were compared and analyzed. Results There was no significant difference in prostate volumes between patients with malignant and benign prostate diseases, and the difference in serum PSA levels was statistically significant(t=2.045, P=0.04). In the SMI group, 20 cases were malignant, puncture positive rate was 51.28%, and the total numbers of puncture were 456 needle points; in the control group, 14 cases were malignant, puncture positive rate was 29.17%, and the total numbers of puncture were 576 needle points; there were significant differences in puncture positive rate and the average numbers of puncture point between the two groups (χ2=4.420, P=0.036; t=13.18, P=0.000). There were 79 cases of malignant pathological tissues and the highest Gleason scores were 7.2±0.4 in the SMI group; in the control group, there were 64 cases of malignant pathological tissues, and the highest Gleason scores were 6.5±0.4; there were significant differences between the two groups in the positive rate of single sampling and the highest Gleason score (χ2=8.232, P=0.004; t=5.940, P=0.000). Conclusion SMI technology to guide prostate cancer biopsy could improve the positive rate of draw materials.

[Objectives]Pulsed load will inject a large number of harmonics into the ship power system. In order to perform harmonic compensation,the phase locking function of the active filter needs to be completed under severe conditions of mains voltage distortion and frequency fluctuation.[Methods]An improved software phase locking method including harmonic suppression and adaptive voltage control is proposed. The parameters such as stability margin,dynamic response and anti-interference of the phase locked loop are optimized. Matlab simulation analysis and hardware verification experiments are carried out.[Results]The simulation results show that the software phase-locked loop can output the correct synchronization signal under non-ideal grid conditions. The hardware experiment results show that the active power filter of the phase-locking method is applicable to the independent small-scale power grids such as ship power system.[Conclusions]The research results can provide reference for the effective management of power quality of ship power system.

[Objectives] Pulsed load has a considerable effect on the power quality and stability of a system. The solutions are different due to the different operation characteristics of pulsed load. To this end, the working characteristics of a diesel generating set under pulsed load in a survey ship are researched.[Methods] Load which changes little in average power is the research object of this paper,and using the inherent mechanical energy storage of diesel generators to stabilize power fluctuation is proposed. Certain factors which influence the dynamic performance of a diesel generating set are analyzed and the stability of change and restoration of speed are attained. As such,the engineering summary of smooth power fluctuations in diesel generating sets is concluded. Based on the actual working conditions of a radar in a survey ship,the capacity and performance of diesel generating sets are calculated according to the formulas.[Results] This research shows that in the worst working conditions in which the load suddenly increases and fluctuates,the speed characteristics and change of the designed generators can meet the requirements.[Conclusions] The results of this research have guiding significance for the preliminary estimation of diesel generating sets under pulsed load.

BackgroundCENDL-3.2 was released in June 2020. Compared with CENDL-3.1, data type and quality has been greatly improved in CENDL-3.2,and most important isotopes including 235U, 238U, 239Pu, 56Fe and others have been re-evaluated and supplemented. Due to its large scattering cross section and small absorption cross section, Be is often used as one of the fuel carrier salt components of molten salt reactor (MSR). The accuracy of reaction cross section data of Be in MSR design cannot be ignored.PurposeThis study aims to examine and analyze the adaptability of the cross section data of Be in CENDL-3.2 to the calculation of MSR problems by the discrete-ordinate method.MethodsBased on CENDL-3.2,the MATXS format multi-group cross section library of 199 neutron groups and 42 photon groups was generated by NJOY, and 35 fast critical benchmarks were selected for its inspection and analysis. Then, results were compared with those of multi-group cross section library based on ENDF/B-7.1 and JENDL-4.0.ResultsThe deviation between the calculated results of the multi-group cross section library based on CENDL-3.2 and the experimental values is less than 0.5% in 26 benchmark cases which is 74.29% of total, outperform those of ENDF/B-7.1 and JENDL-4.0.ConclusionsThe results of this study indicate that the data of Be and the multi-group cross section library based on CENDL-3.2 and its processing method are reliable and can be used in the design of molten salt reactor.

Gut microbiota is important for human health. The complex relationship between intestinal flora and bile acid profile has been studied previously. However, few previous studies have determined the profile and functions of bile acids in different intestinal segments, and whether they are related to the distribution of intestinal flora. In this paper, we measured the distribution of bile acids in different intestinal segments of male and female C57BL/6 mice with ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QqQ-MS) based targeted metabonomics analysis and nuclear magnetic resonance (NMR) based untargeted metabonomics analysis. Gender difference in distributions of bile acids were observed, which was more evident in the lower parts of intestine than in the upper part of intestine, especially in the cecum segment. This might be related to the abundance of gut microflora in different intestine segments. This study provided metabolic phenotypes of bile acids in mice of different genders, and demonstrated their interactions with gut microbiota.

With the development of Micro-satellite,the number of satellites launched every year in the world is gradually increasing. As a key technology in micro-satellite,the release device is required as simple and reliable,without the production of redundancy. Of these release device,the pyrotechnic device is the most widely used. To avoid the formation of space trash by the broken hold-down rod,the unlocked rod needs to set the capture cap to limit its movement. So,the strength and structure form of the capture cap directly influence its functions. Based on the non-linear analysis software ABAQUS,the characteristics of the capture cap’s structure and its fixed form are studied and the weak position of the release device is located and verified. The results of simulation and electric explosion tests show that the weak position of the device can withstand the impact after the pyrotechnic release. This method can be applied to aeronautics and astronautics fields,providing an effective way for the analysis of various types of unlocking devices,such as satellite-rocket separation and rocket fairing separation.

The corrosion behaviour of Q235 steel in Qingdao and Wanning of China,the two kinds of polluted marine environment were simulated by cyclic immersion test, and the correlation of indoor cyclic immersion test and outdoor marine atmospheric corrosion test of Q235 steel were studied. The corrosion morphologies, corrosion products, corrosion kinetics of Q235 steel were investigated with methods of scanning electron microscopy (SEM), X-ray diffraction (XRD) and mass loss. The results reveal that the corrosion morphologies and compositions of corrosion products after cyclic immersion test agree with those after the real atmospheric test. Corrosion prediction model of Q235 steel in two kinds of marine atmospheric environment was built combined with Grey correlation method: T QD=137.002 t 1.093, T WN=102.398 t 0.952.

In view of problems of poor stability, easy to be influenced by interference and bad tracking of desired trajectory existed in excitation controller of synchronous generator based on open-loop iterative learning control, an excitation controller of synchronous generator based on open-closed-loop PID iterative learning control and power system stabilization was designed. A closed-loop feedback control was introduced based on open-loop iterative learning control, current control input was obtained by the last error of input and output and current output error, so as to constitute open-closed-loop PID iterative learning control. Meanwhile, additional positive damping signal provided by power system stabilization was used to improve stability of voltage and power angel of exicitation control system of synchronous generator. The simulation result shows that the excitation controller has strong robustness and improves stability of the system.

Extraction by foam plastics is a common method to determine platinum group elements (PGEs) for most geological samples, however, the high temperature ashing method conducted to release Au and Pt, has complex processing. According to the insoluble residues for Pt in aqua regia, produced by the high temperature ashing method, the analysis results are unstable and produce low recovery rates. The unsatisfactory duplicate results were yielded by the sole use of 20 g/L thiourea as the elution solution. In this paper, this method was improved by decomposing the samples in 50% aqua regia in a closed system, reduced by SnCl2 and concentrated by foam plastics then eluted by 20 g/L thiourea solution-20% hydrochloric acid. Au and Pt were continuously determined by Graphite Furnace Atomic Absorption Spectrometry. The adsorption efficiency was stable under the oscillation time and the absorption temperature of 30 min and 20℃, respectively. The recovery rates of Au and Pt were both greater than 95%. The detection limits of the Au and Pt were 0.23 ng/g and 0.39 ng/g with RSD of 1.8%-10.3% and 1.3%-13.3% (n=10), respectively. The method has been verified by determination of national first grade standard material with satisfactory results. The extraction of foam plastics avoided the high-temperature ashing by being extracted several times with aqua regia and one time in 100℃ water bath which greatly simplified the chemical procedure. Compared with high-temperature ashing, the extraction temperature was greatly reduced, the analysis process was simple and the number of samples was significantly increased for each batch with less interferences and low blanks. The improved method met the needs of various testing of geological samples except for the insoluble Pt minerals by aqua regia.

For problems that high temperature caused by bad contact of isolator of mine-used high-voltage distribution equipment usually leads to faults and the faults are hardly detected, a design scheme of on-line monitoring system for temperature of isolator contact of mine-used high-voltage distribution equipment was put forward and software designs of lower computer program and on-line monitoring program based on LabVIEW of the system were introduced emphatically. The test result showed that the system can monitor temperature of isolator contact of mine-used high-voltage distribution equipment real-timely and remotely with error less than 1 ℃, which can meet requirement of actual project. Besides, the system has functions of fault diagnosis and early warning according to monitored temperature signal.

Objective To study the characteristics and clinical value of intestinal metabolites in children aged 4-6 years with obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods A total of 31 children aged 4-6 years with OSAHS were prospectively enrolled as the test group, and 24 healthy children aged 4-6 years were included as the control group. Relevant clinical indicators were recorded. Fecal samples were collected, and non-targeted metabolomics analysis using liquid chromatography-mass spectrometry was performed to detect all metabolites. Results A total of 206 metabolites were detected, mainly amino acids and their derivatives. There was a significant difference in the overall composition of intestinal metabolites between the test and control groups (P<0.05). Eighteen different metabolites were selected, among which six (N-acetylmethionine, L-methionine, L-lysine, DL-phenylalanine, L-tyrosine, and Lisoleucine) had receiver operating characteristic curve areas greater than 0.7 for diagnosing OSAHS. Among them, Nacetylmethionine had the largest area under the curve, which was 0.807, with a sensitivity of 70.83% and a specificity of 80.65%. Correlation analysis between different metabolites and clinical indicators showed that there were positive correlations between the degree of tonsil enlargement and enterolactone, between uric acid and phenylacetaldehyde, between blood glucose and acetylmethionine, and between cholesterol and 9-bromodiphenyl and procaine (P<0.05). There were negative correlations between the degree of tonsil enlargement and N-methyltyramine, aspartate aminotransferase and indolepropionic acid and L-isoleucine, between alanine aminotransferase and DL-phenylalanine, between indolepropionic acid and L-isoleucine, between uric acid and hydroxyquinoline, and between urea nitrogen and N,N-dicyclohexylurea (P<0.05). The metabolic functional pathways affected by differential metabolites mainly included riboflavin metabolism, arginine and proline metabolism, pantothenic acid and coenzyme A biosynthesis, cysteine and methionine metabolism, lysine degradation and glutathione metabolism. Conclusions Intestinal metabolites and metabolic functions are altered in children aged 4-6 years with OSAHS, primarily involving amino acid metabolism disorders. The screened differential intestinal metabolites have potential screening and diagnostic value as biomarkers for OSAHS. [ABSTRACT FROM AUTHOR]

Objective To constructed a TA-siRNA nanogel to target the inhibition of Schwann cell death. Methods The study used the transcriptome sequencing data of GEO database GSE244328 for bioinformatics analysis to screen pyroptosis-related genes and evaluated the expression level of specific genes through polymerase chain reaction and protein imprint analysis. Mouse Schwann cells from the American ATCC were used, and LPS was used to simulate inflammatory stimulation. Self-assembled TA-siRNA nanogels were prepared, and CCK8 kit experiments, cytoskeleton staining, and scratch experiments were used to evaluate the cell function of TA-siRNA nanogels. GraphPad Prism 8, ImageJ, and R 4.2.1 were used for statistical difference analysis, with P < 0.05 as the statistical difference standard. Results The Gzmb gene was significantly (P < 0.05) highly expressed during the pyroptosis of Schwann cells. TA-siRNA nanogel had excellent biocompatibility with a size of 68.65 ± 7.35 nm and a potential of -36.48 mV, which could be effectively internalized by Schwann cells and did not lead to the elongation and deformation of Schwann cells (P > 0.05). TA-siRNA nanogel could effectively inhibit the Gzmb gene of Schwann cells, thus inhibiting the death of Schwann cells and increasing the survival rate and activity of Schwann cells (P < 0.05). Conclusion Given the role of Schwann cells in PNI, TA-siRNA nanogel inhibition of Schwann cell pyroptosis may be a potential treatment strategy for PNI in the future. [ABSTRACT FROM AUTHOR]

Tea plant, as one of the plants with high fluorine contents, has fluoride-polymerizing property. In this paper, based on scanning electron microscopy, the roots of 'Huangdan' and 'Foshou' were treated with different fluoride concentrations (10 mg·L-1 and 50 mg·L-1) and different time periods (1 d and 16 d). The differentially expressed gene WSD1 of tea wax synthesis under fluoride treatment was screened from the transcriptome data of our research group. The results show that under 50 mg·L-1 fluoride treatment, the epidermal cells of 'Huangdan' root had slightly more wax on the surface and relatively loose cell arrangement, while the epidermal cells of 'Foshou' root had blurred boundaries, significantly more wax on the surface, and fluorine intolerance symptoms such as cell wall distortion and breakage. Quantitative fluorescence results of WSD1 related to wax synthesis show that WSD1 had a significant up-regulation effect on the wax content of tea root under exogenous fluoride treatment. The prediction results of WSD1 protein interaction network and correlation analysis show that WSD1 was negatively regulated by CSS0041298, CSS0012327 and CSS0049082. This study provided a theoretical reference for alleviating fluorine stress in tea plants from the perspective of the interaction between tea plants and wax synthesis, and provided a scientific basis for further exploring the regulation of fluorine absorption in tea plants and the breeding of fluorine-tolerant tea cultivars. [ABSTRACT FROM AUTHOR]

With the rapid popularization of the Internet, the amount of Internet news has increased dramatically. In this case, how to effectively find relevant reports that are more in line with a specific topic has become an urgent problem to be solved. To address this issue, a topic matching algorithm based on the fusion of key entities and text abstracts was proposed in this study. Firstly, the W² NER model was used for named entity recognition to extract key entities using features such as word frequency, TF-IDF, lexical cohesion word-word similarity, and word-sentence similarity. Secondly, the Pegasus model was used for text summarization, and the deep semantic features of news texts were obtained by combining the key entity features with the text summary features using BiLSTM. Next, the cross-attention mechanism was employed to enhance the interaction between the matching news articles by performing feature interaction. Finally, the deep semantic features of the news texts and the text interaction features were fused together to participate in the determination of text topic matching. Comparative experiments were conducted on real data from Sohu, and the results showed that the proposed algorithm achieved similar accuracy and precision compared to other algorithms, while recall and F1 score were improved. [ABSTRACT FROM AUTHOR]

The influence of laser cutting parameters on cutting quality of tussah by CO laser was studied, and the optimal combination of technical parameters was obtained. Orthogonal test method was used to study the influence of light intensity, feed speed and lens on seam width and seam depth, and to analyze the variation rule of main effect and interaction test data. The results showed that the main factor affecting laser cutting was lens height, and the interaction between feed speed and light intensity was significant. In actual production, the optimal combination of technical parameters can be determined according to different cutting effects required, such as laser cutting of tussah wood with water content of 6.5%, in order to obtain seam depth of about 3 000 μ m, seam width of about 200 μ m, 5 mm lens height, 40 mm/s feed speed and 40% laser intensity. [ABSTRACT FROM AUTHOR]

This study used ArcGIS to visualize the spatial distribution of barium in soil, and analyzed the adsorption and migration characteristics of barium in soil-groundwater system. Furthermore, the human health risk index was applied to evaluate the human health risk of barium in soil-groundwater. The results showed that barium was mainly accumulated in the area of chlor-alkali enterprises, with a maximum concentration of 25 000 mg kg-1 and an average concentration of 1 584 mg·kg-1, far higher than the regional background value of 292.6 mg·kg-1. The adsorption of the soil for barium could be described by linear isothermal adsorption equation and Kd was 0.0011, indicating that the absorption capacity of soil for barium was weak. Leaching test showed that the concentration of barium in the leachate reduced with time and stabilized at 40 mg·L-1 on the fourth day. Due to the high content of barium in the leachate, the leachate could be hazardous to the groundwater system. Visual MODFLOW model showed that the maximum anticipated barium concentrations in the nearby and downstream rivers were 147 mg L-1 and 13.9 mg L-1, respectively, far exceeding the Class III screening value (0.7 mg·L-1) in Standard for Groundwater Quality (GB/T 14848-2017) and the standard value (0.7 mg·L-1) in Environmental Quality Standards for Surface Water (GB 3838-2002). The human health risk index of barium in soil-groundwater was assessed according to the human health risk assessment model. It was found that the hazard index (HI) of barium in the soil to children was lower than that of adults, with 0.545 and 1.018, respectively, which was contrary to previous human health risk assessment conclusions for other heavy metals. The hazard index of adults exceeded the acceptable range of non-carcinogenic health risks (HI<1), indicating that there is a non-carcinogenic risk (NCR) for adults from the barium. At 10 m, 200 m downstream of groundwater, and in the Pi River system, the HI values of barium for children were 27.788, 16.021, and 2.628, while the values for adults were 21.215, 12.232, and 2.006, respectively. This showed that barium caused some harm to humans after diffusing into underground water. In conclusion, barium pollution in soil-groundwater is detrimental to human health, which may result from the leaching of barium-containing liquid in the chlor-alkali business. [ABSTRACT FROM AUTHOR]

To guide significance for water management of winter rape in Hebei Province, effect of pre-winter irrigation on yield formation of winter rapeseed was studied. Materials included 12 winter Brassica rapa and 9 B. napus varieties (lines), they were irrigated before winter. The traits were investigated including overwintering rate, contents of N, P and K in leaves and siliques, and yield composition. Results showed that winter irrigation effectively prevented freezing injury of rapeseed, increased the overwintering rate, and then improved later growth, agronomic characteristics and yield formation. The overwintering rate reached more than 90%, significantly higher than non-winter irrigation control. Although winter irrigation treatment had no significant effect on growth duration, it significantly improved agronomic traits of branch length, plant height and plot yield by 33%, 90.3% and 16.9% respectively. The contents of N and P in leaves, and K in silique shell of 6 tested winter rapeseed were higher than the other organs. [ABSTRACT FROM AUTHOR]

【Objective】There is a problem that traditional unrepeatered transmission system need to use disturbed Raman amplifier and remote optical pump amplifier, while both of these two amplifiers need to use high power pump laser which will increase the complexity of fiber link in unrepeatered transmission system. In this paper, we propose a new structure of unrepeatered transmission system using Erbium Doped Optical Fiber Amplifier (EDFA) to replace the forward disturbed Raman amplifier.【Methods】We analyze and compare the performance of the proposed unrepeatered transmission system, and realize a real-time unrepeatered transmission experiment with the proposed structure.【Results】The results show that the gain effect of forward Raman pump in traditional unrepeatered communication system can be achieved by using high power amplifier to increase the signal launch power, and the new structure of unrepeatered transmission system is more suitable to achieve higher bitrate with the help of Wavelength Division Multiplexing (WDM) technology. We confirm the unrepeatered transmission system can achieve 500 km span distance at 10 Gbit/s bit rate in single channel communication transmission, and 500 km span distance at 4×10 Gbit/s bit rate in the WDM technology.【Conclusion】The proposed unrepeatered transmission system can simplify the traditional unrepeatered transmission system, and increase the bit rate by using multi-channel WDM system with EDFA. It has important practical significance to simplify the structure and improve the bit rate in future unrepeatered transmission system.

A direct current power flow controller is a key device for regulating steady-state power flow in multi-terminal DC （direct current） grids. In response to the limitations of existing DC power flow controllers， a novel multi-port DC power flow controller is designed by incorporating a cascaded submodules with adjustable DC output voltage in a circular branch. Firstly， the topology and operation principles of the proposed controller are explained. Then， its control strategies and parameter selection methods are introduced. Finally， the performance of the DC power flow controller is validated through electromagnetic transient simulations on a five-terminal DC grid with eight DC lines. The results indicate that the proposed controller can simultaneously regulate power flow on multiple DC lines connected to the same DC bus， demonstrating advantages of modularity and easy scalability.

With the rapid development of industry, large amount of refractory organic pollutants in domestic and industrial wastewater are discharged into water bodies, posing a serious threat to human health and the environment. Advanced oxidation processes (AOPs) based on persulfates have shown outstanding performance in treating refractory organic wastewater, and the use of single-atom catalysts (SACs) can maximize the utilization of metal atoms and reduce the leaching of metal ions, which has a promising application prospect in the activation of persulfates for the degradation of organic pollutants. The preparation methods of single-atom catalysts were summarized, and the advantages and disadvantages of various methods were discussed. The application of single-atom catalysts with metals such as Fe, Co, Mn and Cu in the activation of persulfates for the degradation of organic pollutants was discussed. The mechanisms of single-atom catalysts in activating persulfates and the degradation mechanisms of the persulfate system catalyzed by single-atom catalysts towards organic pollutants were summarized. Finally, the future development of single-atom catalysts in activating persulfates for the degradation of organic pollutants was discussed.

Abstract [Objective] This study aims to investigate the effects of drought stress on the distribution of carbon (C), nitrogen (N), and phosphorus (P) elements and stoichiometry in organs of Pinus yunnanensis seedlings, and to provide a theoretical basis for water management in the cultivation of P . yunnanensis. [Methods] The contents of C, N, and P in organs of 1-year-old P . yunnanensis seedlings under drought stress were determined by potted water control method and four drought treatments. [Results] (1) Compared with the appropriate water treatment, the C content in leaves, stems, and fine roots of P . yunnanensis seedlings was decreased under drought stress, but was increased in coarse roots. N content was decreased in coarse roots and increased in fine roots. P content was increased in leaves and decreased in stems. (2) The variation coefficient of element content was P>N>C. The contents of C and N showed the greatest variability in fine roots. The variability of P content was the highest in leaves and the lowest in coarse roots. (3) There was a significant negative correlation between N content and coarse roots, a significant positive correlation between stems and fine roots, and a significant positive correlation between N and P contents in stems and coarse roots. [Conclusion] Under drought stress, growth of P . yunnanensis seedlings is restricted by N elements, and the utilization efficiency of N and P is increased. The overall variability of C, N, and P content in coarse and fine roots is higher than leaves and stems. The root system is more sensitive to changes in soil water status.

To study the effect of soft segments of thermoplastic polyurethane elastomer (TPU) material on the sealing performance of hydraulic cylinders, a series of TPU materials were synthesized by polybutylene adipate diol (PBA),polycarbonate diol (PCDL), polycaprolactone diol(PCL), polytetrahydrofuran ether diol ( PTMEG ), diphenyl methane-4, 4'--diisocyanate (MDI) and hydroquinone dihydroxyethyl ether (HQEE).The effects of soft segment types on physical and mechanical properties, friction and wear properties, hydraulic oil aging properties and sealing properties of TPU materials were studied. The results show that the four kinds of TPU materials synthesized by four soft segments have good physical and mechanical properties. PBA-type TPU material has the best wear resistance, and the friction coefficient of the TPU materials synthesized by four soft segments under the condition of hydraulic oil lubrication is 0. 05, indicating a lower friction coefficient. PCDL--type TPU material has the best tolerance to hydraulic oil and sealing performance. PCDL--type TPU material is an ideal material for manufacturing hydraulic cylinder seals. [ABSTRACT FROM AUTHOR]

The aim of the experiment was to screen out high quality oat varieties suitable for planting in Tumet Right Banner, Inner Mongolia. Ten oat varieties were used as test materials, and their phenological period, agronomic characters, yield characters and nutritional quality were analyzed. The results showed that 10 oat varieties could complete the whole growth and development process in experimental area, and the growth period was 87~110 d. The plant height of Dingyan No. 2 was significantly higher than that of other varieties (P<0.05), while the plant height of Mengyan No. 1 was significantly lower than that of all other varieties (P<0.05). The grain yield of Bayou No.18 was the highest, followed by Bayan No.6, and Yuanza No.1 was significantly lower than that of other varieties (P<0.05). The hay yield of Dingyan No.2 and Bayou No. 18 was significantly higher than that of other varieties (P<0.05), while that of Yuanza No. 1 was significantly lower than that of all other varieties (P<0.05). GL381 had the highest crude protein content and Quebec had the lowest crude protein content. The highest crude fat content was Baoyou No.3, and the lowest was Mengyan No.1 and Dingyan No.2 crude fiber content was the highest, Bayou No.3 crude fiber content was the lowest. The crude ash content than that of other varieties (P<0.05), and Bayou No.3 was significantly lower than that of other varieties (P<0.05). Bayou No.3 had the highest relative feeding value (107.67), while Dingyan No.2 had the lowest. The comprehensive analysis of grey correlation degree showed that Zhangyan No. 4, Bayou No.18 and Bayou No.3 had better performance in terms of production performance and nutritional quality. The study indicates that Zhangyan No.4, Bayou No.18 and Bayou No.3 are suitable for planting and promoting in Tumet Right Banner and its surrounding areas. [ABSTRACT FROM AUTHOR]

In order to analyze the vehicle-bridge coupling of viaducts for multi-line subway, this paper establishes a metro train-bridge coupling model based on ANSYS's parametric design language (APDL), for considering the operation of single and double lines. The prototype bridge is a three-span continuous viaduct for four-line subway, and the train type is the type-B metro train of six cars (4 motor cars and 2 trailers cars). The dynamic response of the viaduct for metro train operations along different single and double lines is analyzed. The results show that the influence of metro train on the viaducts' lateral displacement and acceleration is small. When the double-line trains run simultaneously in opposite direction, the vertical displacement and acceleration responses of the bridge are greater than the case of running along a single line, and the internal forces of the bridge's critical section is approximately 67%--99% of the sum as the train running along a single line. The numerical model and calculation results presented in this paper can provide a theoretical method and evaluation basis for the study of train-bridge coupling vibration of multi-line subway viaduct. [ABSTRACT FROM AUTHOR]

Pancreatic cancer, one of the most lethal cancers in the world, has been increasing in incidence and mortality year by year, and the overall prognosis of patients is poor. Early detection and effective treatment are crucial for improving the prognosis and survival rates of pancreatic cancer patients. Unlike traditional imaging, emerging molecular imaging can visualize the abnormalities at the molecular or cellular level in the process of tumor development. At present, multimodality molecular imaging that integrates multiple imaging methods to achieve complementary advantages and multifunctional nanoplatforms with integrated diagnosis and treatment functions have become research hotspots in the field of molecular imaging. Remarkable progress has been made in preclinical research concerning magnetic-optical multimodality molecular imaging probes and their derived multifunctional nanoplatforms, which provides new ideas for early detection, accurate treatment and efficacy evaluation of pancreatic cancer.

Electrocoagulation was used to treat the high temperature super-heavy oil produced water. The effects of relevant factors were studied, including reaction time, current density and plate distance. The response surface methodology was used to optimize the process conditions. The mechanisms of purification in electrocoagulation and factors affecting electrode passivation were also studied. The results showed that the electrocoagulation could effectively remove oil, COD, and SiO2 from high temperature super-heavy oil produced water. Reaction time had a significant impact on the removal rate of COD and SiO2. When the reaction time was 27.2 min, the current density was 8.6 mA/cm2, and the electrode distance was 1.8 cm, the removal rates of COD and SiO2 were 80.95% and 100% respectively. Electrocoagulation played an important role in the removal of organic matter, which was the multinuclear hydroxy aluminum complex colloid generated by the combination of aluminum ions and OH-. The increase of Cl- in the produced water slightly weakened the passivation of aluminum plates. The increase of SO42- and HCO3- increased the passivation of aluminum plates. When the produced water was neutral, the passivation of aluminum plate was the highest.

[ Objective ] It is of great significance to explore the distribution of NSC ( non-structural carbohy- drate ) and their components in different organs with seasonal changes for revealing the mechanism of car- bon distribution in different age Pinus armandii . [ Methods ] The contents of NSC and their components in different organs of young and middle-aged P . armandii were determined by periodic sampling to explore the seasonal changes of P . armandii during the year. [ Results ] ( 1 ) The distribution pattern of NSC and their components in different age P . armandii was the same among all organs , where the starch content was in the order : Roots > leaves > branches > stems. The starch content in stems was significantly low- er than that in other organs , while the content of soluble sugar and NSC in leaves , roots and branches was not significantly different. The ratio of sugar to starch in stems was significantly higher than that in other organs. ( 2 ) During the growing season , NSC and their components were mainly affected by seasons , fol- lowed by the interaction between seasons and organs , and the influence of forest age was the least. ( 3 ) The correlation between NSC and their components in different P . armandii organs was the same. Except the negative correlation between the ratio of sugar to starch and starch , NSC in young-aged P . armandii and the ratio of sugar to starch and starch in middle-aged P . armandii , the other indexes were positively correlated. [ Conclusion ] NSC and their components in various organs of P . armandii had obvious season- al fluctuations. When the environment changed , the carbon supply and demand of different organs changed synergistically , which was conducive to the growth of P . armandii , and enhanced its resistance and adaptability to cope with extreme environment.